CN101153696A - Electro-optic device, image forming device - Google Patents

Abstract

An electro-optical device, comprising a light source array in which a plurality of light emitting elements are arranged in one direction on a substrate, and a lens array in which a plurality of lens elements for imaging the emitted light from the light emitting elements on an image carrier are arranged in the one direction , a first light transmission member and a second light transmission member disposed between the light source array and the lens array in such a manner as to be in contact with the light source array and the lens array, the first light transmission member and the second light-transmitting member are connected and disposed in the one direction, and the elastic modulus, refractive index, and light transmittance of the first light-transmitting member and the second light-transmitting member are at least a difference.

Description

Electro-optical device, image forming device

technical field

The present invention relates to an electro-optical device having an electro-optic panel in which light-emitting elements such as EL elements and electro-optical elements such as light valve elements are arranged, an image forming apparatus using the electro-optic device, and a method for manufacturing the electro-optic device.

Background technique

As a linear print head for writing an electrostatic latent image on an image carrier (such as a photoreceptor drum) of an electrophotographic image forming apparatus, an electroluminescent element (hereinafter referred to as "EL element") is used. array technology. In such a technique, generally, a condensing lens array is disposed between the EL element array and the image carrier. As the lens array, there is, for example, SLA (Self Focusing Lens Array) available from Nippon Panel Glass Co., Ltd. (self-focus/SELFOC is a registered trademark of Nippon Panel Glass Co., Ltd.). Each of the distributed refractive index lenses of the condensing lens array is a graded-index optical fiber formed so that the refractive index on the central axis is low, and the refractive index increases as the distance from the central axis increases. When the light passes through, an erect image of the image on the EL element array is formed on the image carrier. The images obtained by multiple refractive index distributed lenses form a continuous electrostatic latent image on the image carrier. (For example, refer to JP-A-2006-205430)

In such a print head described in JP-A-2006-218848, in order to reduce the loss of light emitted from the EL elements, a light-transmissive spacer (spacer) is disposed between the EL element array and the condensing lens array. )Technology. In such a configuration, compared with a configuration in which only air exists between the light source array and the lens array, the light beams from the EL elements toward the lens array are narrowed. Therefore, it is possible to increase the ratio (light utilization efficiency) of the amount of light incident on the lens array among the emitted light from the light source array.

In such a print head, when a plurality of EL elements emit light, it is desired that the optical characteristics of the spot irradiated onto the image carrier from these EL elements be uniform. That is, it is desirable that a spot caused by light from a certain EL element and a spot caused by light from another EL element have as similar optical characteristics as possible.

Contents of the invention

Therefore, the present invention provides an electro-optical device, an image forming device using the electro-optic device, and a method of manufacturing the electro-optic device, which can improve the uniformity of optical characteristics of a point irradiated from the electro-optical device to an image carrier when driving a plurality of electro-optical devices. .

Description of drawings

FIG. 1 is a perspective view showing a partial configuration of a printer according to a first embodiment of the present invention.

Fig. 2 is a plan view schematically showing a light source array according to an embodiment of the present invention.

Fig. 3 is a perspective view of a lens array according to an embodiment of the present invention.

4 is a side view of a print head which is an electro-optical device according to a first embodiment of the present invention.

5 is a side view showing a partial configuration of the printer according to the first embodiment of the present invention.

6 is a side view showing a print head which is an electro-optical device according to a modified example of the first embodiment of the present invention.

7 is a perspective view showing a partial configuration of a printer according to a second embodiment of the present invention.

Fig. 8 is a side view of a print head according to a second embodiment of the present invention.

9 is a side view of a print head according to a modified example of the second embodiment of the present invention.

FIG. 10 is a perspective view schematically showing a part of a conventional image forming apparatus.

FIG. 11 is a perspective view schematically showing a condensing lens array of the image forming apparatus shown in FIG. 10 .

Fig. 12 is a cross-sectional view of the converging lens array of Fig. 11 .

FIG. 13 is a schematic side view showing a part of the image forming apparatus of FIG. 10 .

FIG. 14 is a graph showing the characteristics of the imaging radius R of the image forming apparatus of FIG. 10 .

15 is a plan view of an electro-optical device according to a third embodiment of the present invention.

Fig. 16 is a side view (front view) of the electro-optic device of Fig. 15 .

FIG. 17 is a graph showing the characteristics of the imaging radius R of an image forming apparatus using the electro-optical device of FIG. 15 as an optical head.

18 and 19 are diagrams illustrating a method of manufacturing the electro-optical device of FIG. 15 .

20 and 21 are diagrams showing other methods of manufacturing the electro-optical device of FIG. 15 .

Fig. 22 is a side view (front view) of an electro-optical device according to a fourth embodiment of the present invention.

23 to 26 are diagrams illustrating a method of manufacturing the electro-optical device of FIG. 22 .

Fig. 27 is a graph showing the relationship between light emitting elements and luminance of a conventional electro-optic device.

Fig. 28 is a plan view showing an electro-optical device according to a fifth embodiment of the present invention.

FIG. 29 is a side view of the electro-optical device of FIG. 28 .

FIG. 30 is a graph showing the relationship between light-emitting elements and brightness in the electro-optical device of FIG. 28 .

31A and 31B are explanatory views showing an example of the manufacturing process of the electro-optical device.

32A and 32B are explanatory views showing other examples of the manufacturing process of the electro-optical device.

Fig. 33 is a side view showing an electro-optical device according to a sixth embodiment of the present invention.

34A to 34D are explanatory views showing an example of the manufacturing process of the electro-optical device.

35 is a longitudinal sectional view showing an example of an image forming apparatus according to an embodiment of the present invention.

36 is a longitudinal sectional view showing another example of the image forming apparatus according to the embodiment of the present invention.

Detailed ways

Hereinafter, various embodiments of the present invention will be described with reference to the drawings.

In the drawings referred to in the description of each of the following embodiments, the dimensional ratio of each part is suitably different from the actual one.

first embodiment

1 is a perspective view showing a partial configuration of an electrophotographic printer 1 (image forming apparatus) to which a print head 2 (electro-optic device) according to a first embodiment of the present invention is applied.

As shown in FIG. 1 , a printer 1 has a print head 2 and a photoreceptor drum 3 that is an image carrier. The photoreceptor drum 3 is supported by a rotation shaft extending parallel to the longitudinal direction of the print head 2 , and rotates with its outer peripheral surface facing the print head 2 . The print head 2 is used as an exposure device of the printer 1 .

The print head 2 has: a substantially rectangular light source array 4 in which a plurality of light-emitting elements are arranged on the substrate; a lens array 5 formed by arranging and disposing lens elements that make the outgoing light from the light source array 4 form a positive image on the photoreceptor drum 3; The isolator member 6 is disposed between the light source array 4 and the lens array 5 .

FIG. 2 is a plan view schematically showing the light source array 4 . The light source array 4 is an element substrate 7 made of a substantially rectangular high-purity glass (glass) as a main component, and a light-emitting element array 8A in which light-emitting elements, that is, a plurality of organic EL (electroluminescent) elements 8 are arranged, is integrally formed. A drive element group consisting of a plurality of drive elements 9 for driving the organic EL element 8, and a control circuit 9a for controlling driving of these drive elements 9 (drive element group). It should be noted that, in FIG. 2 , the organic EL elements 8 are arranged in one row, but they may be arranged in two rows in a zigzag shape. In this case, the interval between the organic EL elements 8 in the longitudinal direction of the light source array 4 can be reduced, and the resolution of the printer can be improved.

The organic EL element 8 has at least an organic light-emitting layer between a pair of electrodes, and emits light by supplying a current to the light-emitting layer from the pair of electrodes. One electrode of this organic EL element 8 is connected to a common line 10 , and the other electrode is connected to a data line 11 via a drive element 9 . The drive element 9 is constituted by a switching element such as a thin film transistor (TFT) or a thin film diode (TFD). When a TFT is used as the driving element 9, the data line 11 is connected to the source region, and the control circuit 9a is connected to the gate. Further, the operation of the drive element 9 is controlled by the control circuit group 9 a, and the drive element 9 controls the conduction of electricity from the data line 11 to the organic EL element 8 .

A sealing body 12 for sealing the organic EL elements 8 is bonded to the portion of the element substrate 7 where the organic EL elements 8 are arrayed. This sealing body 12 cooperates with the element substrate 7 to seal an approximately rectangular plate material of the organic EL element 8 (shielded from outside air), and its long side is arranged along the long side direction of the element substrate 7 . Thereby, deterioration of the organic EL element 8 due to adhesion of external air or moisture can be suppressed. It should be noted that the control circuit 9 a is mounted on the element substrate 7 not covered by the sealing body 12 .

The light source array 4 configured in this way is of a bottom emission type, and the element substrate 7 is disposed downward (see FIG. 1 ). The linear expansion coefficient (ratio of length change with temperature change) of the element substrate 7 which is a main constituent member of the light source array 4 is, for example, about 3.8×10 ⁻⁶ /°C.

FIG. 3 is a perspective view of the lens array 5 . The lens array 5 is constituted by arranging self-focusing (registered trademark) lens elements 51 a of Nippon Panglass Corporation. The lens element 51a is formed in a fibrous shape with a diameter of about 0.28 mm. In addition, each lens element 51a is arranged in a zigzag shape, and the gap between each lens element 51a is filled with black silicone resin 52 . A frame 54 is arranged around it to form the lens array 5 .

The lens element 51a has a parabolic refractive index distribution from the center to the periphery. Therefore, the light incident on the lens element 51a advances while oscillating at a constant period inside the lens element 51a. If the length of the lens element 51a is adjusted, the image can be formed with equal magnification. Furthermore, according to the lens of equal magnification, images formed by adjacent lenses can be superimposed, and images of a wide range can be obtained. Therefore, the lens array 5 in FIG. 3 can image the light from the entire light source array with high precision. Incidentally, the coefficient of linear expansion of the lens array 5 is, for example, about 1.0×10 ^-5 /°C.

Returning to FIG. 1 , the spacer member 6 is formed of a light-transmitting material such as glass or plastic. The isolator member 6 has a substantially rectangular cross section perpendicular to the longitudinal direction, and its length in the longitudinal direction is shorter than that of the light source array 4 and longer than that of the lens array 5 . In addition, the length of the isolator member 6 in the short direction (width direction) is shorter than the length of the light source array 4 in the short direction, and longer than the length of the lens array 5 in the short direction. In addition, the length of the spacer member 6 in the thickness direction (height direction, vertical direction in FIG. 1 ) is shorter than the length of the width direction in a cross section perpendicular to the longitudinal direction. The linear expansion coefficient of the separator member 6 is, for example, about 9.4×10 ⁻⁶ /°C.

The light source array 4, the lens array 5, and the spacer member 6 constituted in this way are shown in FIG. The lens array 5 is bonded to the upper side with a light-transmitting adhesive 14, and the print head 2 is integrated. The overall size of the print head 2 is about 230 to 240 mm in the longitudinal direction for A4 size paper, and about 320 to 330 mm in the longitudinal direction for A3 size paper.

FIG. 4 is a side view of the print head 2 . As shown in FIG. 4, the adhesive 13 is comprised of two types of adhesives, such as a 1st adhesive 13a and a 2nd adhesive 13b. Similarly, the adhesive 14 is also composed of two types of adhesives, such as the first adhesive 14a and the second adhesive 14b.

At one end (the right side in FIG. 4 ) of each of the element substrate 7 of the light source array 4, the lens array 5, and the spacer member 6, apply Each first adhesive 13a, 14a

For each of the first adhesives 13a and 14a, for example, a thermosetting adhesive or an ultraviolet curing adhesive is used. Specifically, there can be mentioned UV-curable epoxy-based adhesives manufactured by Daikin Industries, Ltd., which have a refractive index close to that of glass, 1.514, and a light transmittance of 90% or more (at a film thickness of 0.1 mm). optodyne (registered trademark) UV-3200, a UV curable epoxy adhesive with a refractive index higher than that of glass of 1.63 after solidification, optocrave (trademark) HV153 manufactured by Adell Co., Ltd., and a refractive index after solidification of 1.567 The preferred UV-curable epoxy-based adhesive is optodyine (registered trademark) UV-4000 manufactured by Daikin Industries, Ltd., but it is not limited thereto.

The light source array 4 and the spacer member 6 are bonded to each other with a predetermined interval maintained by the first adhesive 13a. In addition, the spacer member 6 and the lens array 5 are bonded to each other with a predetermined interval maintained by the first adhesive 14a. It should be noted that the distances d1 and d2 between the element substrate 7 of the light source array 4 and the isolator member 6 , and between the isolator member 6 and the lens array 5 are, for example, about 10 μm.

On the other hand, the respective second adhesives 13b, 14b are applied to the adhesive surfaces of the light source array 4, the lens array 5, and the spacer member 6 other than the portions where the first adhesives 13a, 14a are applied. The occupied areas of the second adhesives 13b, 14b are set to be larger than the occupied areas of the first adhesives 13a, 14a on the respective adhesive surfaces.

For the second adhesives 13b, 14b, use a gel-like composition or a rubber-like composition with a smaller elastic modulus than the first adhesives 13a, 14a, and have the same properties as the first adhesives 13a, 14a. Refractive index, light-transmitting adhesive.

The actions of the adhesives 13 and 14 of the print head 2 configured in this way will be described.

FIG. 5 is a side view showing a partial configuration of the printer 1 . As shown in FIG. 5, in the print head 2, the light source array 4, the lens array 5, and the spacer member 6 expand when the temperature rises, for example, due to heat generated by the organic EL element 8 or peripheral devices (not shown). At this time, each thermal expansion coefficient (thermal expansion coefficient) is different (hereinafter, as in the first embodiment, the case where the linear expansion coefficient of the spacer member 6 is larger than the linear expansion coefficient of the light source array 4 is described, so due to the shape change (degree of expansion) For example, when the temperature changes in Fig. 5, the stretching rate in the direction of arrow A is different), deformation occurs, and the two ends of the long side direction of the print head 2 are warped in the direction away from the photoreceptor drum 3 to be arc-shaped (Fig. 5 double-dotted line). If the print head 2 is tilted into an arc shape, then for the specified distance L1 between the photoreceptor drum 3 and the lens array 5, along with the lengthwise center of the print head 2 toward both ends , the distance between the photoreceptor drum 3 and the lens array 5 gradually becomes longer (the position shift of the lens array). Accordingly, for the standard imaging position (reference position), that is, the position P of the surface of the photoreceptor drum 3, the actual The imaging position shifts in the direction of the optical axis, and the optical characteristics of the reference position deteriorate (image blurring).

However, in the first embodiment, the second adhesives 13b, 14b composed of a gel-like composition or a rubber-like composition with a small elastic modulus are applied over a wide range on each adhesive surface, so the second The adhesives 13b, 14b deform elastically, thereby absorbing distortion caused by the difference in thermal expansion rate (thermal expansion coefficient) of the light source array 4 , the spacer member 6 , and the lens array 5 . Therefore, it is possible to prevent the print head 2 from being deformed into a bowed shape.

Therefore, according to the above-mentioned first embodiment, the print head 2 does not warp even when the temperature rises, and a predetermined distance is kept from the photosensitive drum 3 at any place on the surface of the lens array 5 facing the photosensitive drum 3 . L1. Furthermore, the first adhesives 13a and 14a function as adhesives for fixing that the distance between the element substrate 7 of the light source array 4 and the spacer member 6, and the distance between the spacer member 6 and the lens array 5 are always kept at predetermined intervals. . Therefore, even when the second adhesive 13b, 14b elastically deforms, it does not have any influence on the print head 2 . Therefore, it is possible to prevent the optical characteristics of the image formed on the photoreceptor drum 3 from deteriorating.

The spacer member 6 is mainly made of glass or plastic material, and the lens array 5 is made of plastic softer than the spacer member 6 , so the elastic modulus of the lens array 5 is smaller than that of the spacer member 6 . Therefore, the spacer member 6 and the lens array 5 may be bonded to each other using only the first adhesive 14a, that is, the first adhesive 14a may be used instead of the second adhesive 14b. In doing so, the lens array 5 absorbs deformation due to the difference in thermal expansion coefficients of the spacer member 6 and the lens array 5 . Therefore, it is difficult for the print head 2 to be raised in an arcuate shape.

That is, it can be said that the deformation (warping) of the print head 2 is largely caused by the rigidity of the parts (light source array 4, lens array 5, and spacer member 6). Therefore, only the first adhesive 14a can be used to bond the spacer member 6 and the lens array 5, and like the light source array 4 and the spacer member 6, the coefficients of thermal expansion are different, and when materials with strong rigidity are joined together, distortion will occur. The influence of α is large, and deformation (warping) is likely to occur by bonding only by the first adhesive 13a.

In addition, in the above-mentioned first embodiment, the case where the first adhesives 13a, 14a are applied to the corresponding one ends of the element substrate 7 of the light source array 4, the lens array 5, and the spacer member 6 respectively (refer to Figure 4). However, as shown in FIG. 6 , the element substrate 7 of the light source array 4 , the lens array 5 , and the center of the spacer member 6 in the longitudinal direction are applied over substantially the entire width direction (short direction) of the print head 2 . The first adhesive 13a, 14a is coated with the second adhesive 13c, 13d, 14c, 14d on the adhesive surface other than the first adhesive 13a, 14a.

In such a structure, compared with the case where the first adhesive 13a, 14a is applied to one end of the element substrate 7 of the light source array 4, the lens array 5, and the spacer member 6, the relationship between them can be more reliably maintained. The distance d1, d2, and can maintain a stable joint state.

It should be noted that at this time, like the second adhesives 13b and 14b, the second adhesives 13c, 13d, 14c, and 14d are made of gels with a softer elastic modulus than the first adhesives 13a, 14a, respectively. It is composed of a jelly-like composition or a rubber-like composition, and has the same refractive index and light-transmitting properties as the first binders 13a and 14a.

Furthermore, in the above-mentioned first embodiment, instead of the second adhesives 13b, 14b, 13c, 13d, 14c, 14d, it is also possible to use non-adhesive and curable adhesives that have the same properties as the first adhesive. 13a and 14a have the same refractive index and light-transmitting liquid (such as silicone oil). Even if the liquid is injected into the gap between the element substrate 7 of the light source array 4 and the isolator member 6 and the gap between the isolator member 6 and the lens array 5, the respective gaps d1 and d2 are about 10 μm, so they are held in the gap by surface tension. , will not overflow from print head 2.

If a liquid is used instead of the second adhesive 13b, 14b, 13c, 13d, 14c, 14d, it can absorb the coefficient of thermal expansion more effectively than the second adhesive 13b, 14b, 13c, 13d, 14c, 14d The expansion and contraction changes of each part caused by the difference. Therefore, it is possible to more reliably prevent degradation of the optical characteristics of the image formed on the photoreceptor drum 3 .

In addition, after the element substrate 7, the spacer member 6, and the lens array 5 are bonded using only the first adhesive 13a, 14a, the manufacturing operation is completed only by injecting liquid into these gaps, so that the working time can be shortened.

In addition, the intervals between the light source array 4, the lens array 5 and the spacer member 6 can be determined by applying the first adhesive 13a, 14a to each position, without the second adhesive 13b, 14b, 13c, 13d, 14c. , 14d or liquid, print head 2 can also be used. However, at this time, not only the mutual positional relationship of the parts becomes unstable, but also there is air between the light source array 4 and the lens array 5, so the proportion of the light incident on the lens array 5 among the emitted light from the light source array 4 decreases. . The second adhesive 13b, 14b, 13c, 13d, 14c, 14d or liquid is buried in the adhesive surface (gap portion) other than the first adhesive 13a, 14a, so that the mutual positional relationship of each part is stable, Furthermore, it is possible to increase the ratio of the amount of light incident on the lens array 5 among the emitted light from the light source array 4 .

second embodiment

Next, a second embodiment of the present invention will be described based on FIG. 2 , FIG. 3 , FIG. 7 , and FIG. 8 . The same code|symbol is attached|subjected to the same element as 1st Embodiment, and it demonstrates.

In the second embodiment, the basic structure of the printer 30 including the print head 31 and the photoreceptor drum 3 is the same as that of the first embodiment.

FIG. 7 is a perspective view showing a partial configuration of a printer 30 to which a print head 31 according to a second embodiment is applied. FIG. 8 is a side view of the print head 31 .

The print head 2 of the first embodiment has a light source array 4 , a lens array 5 , and a spacer member 6 provided between the light source array 4 and the lens array 5 , and is bonded by adhesives 13 and 14 , respectively. However, in the print head 31 of the second embodiment, as shown in FIG. Connect the light source array 4 and the lens array 5.

As shown in FIG. 8 , the light source array 4 and the lens array 5 are bonded to each other with a light-transmitting adhesive 13 .

The adhesive 13 is composed of two types of adhesives, the first adhesive 13a and the second adhesive 13b. The first adhesives 13a, 14a are applied across the width direction (short side direction) of the print head 31 to respective one ends (right side in FIG. 8 ) of the light source array 4 and the lens array 5 .

On the other hand, the second adhesive 13b is applied to the bonding surface of the light source array 4 and the lens array 5 other than the portion where the first adhesive 13a is applied. The area occupied by the second adhesive 13b is set to be larger than the area occupied by the first adhesive 13a on the adhesive surface.

Therefore, according to the second embodiment described above, the same effect as that of the first embodiment can be obtained. There is no spacer member 6 between the light source array 4 and the lens array 5 , and a light-transmitting adhesive 13 is used to bury the space between them. Therefore, it is possible to increase the ratio of the amount of light incident on the lens array 5 among the emitted light from the light source array 4 (light utilization efficiency), and reduce the number of parts.

In the above-mentioned second embodiment, the case where the first adhesive 13a is applied to the corresponding one ends of the element substrate 7 of the light source array 4 and the lens array 5 (refer to FIG. 8 ), but as shown in FIG. 9 , it is also possible to apply the first adhesive 13a across the width direction (short side direction) of the print head 31 on the element substrate 7 of the light source array 4 and the long side direction central part of the lens array 5, and in the first bonding The adhesive surfaces other than the adhesive 13a are coated with the second adhesives 13c and 13d.

According to this structure, compared with when the first adhesive 13a is applied to one end of the element substrate 7 of the light source array 4 and the lens array 5, the gap between the element substrate 7 of the light source array 4 and the lens array 5 can be more reliably maintained. distance, and can maintain a stable joint state.

The print heads 2 and 31 of the first and second embodiments described above can be used in an electrophotographic printer 1 (image forming apparatus). The printer will be described in detail later. Since such a printer has the print heads 2 and 31 according to the embodiment, it is possible to prevent the print head 2 from warping even when the temperature rises. Therefore, it is possible to provide an excellent printer capable of preventing deterioration of the optical properties of the image formed on the photoreceptor drum 3 and realizing a high-quality output image. In addition, it is possible to provide a printer that is excellent in print quality and reliability even if the print speed is increased.

In addition, in each of the above-mentioned embodiments, as a plurality of electro-optic elements whose light emission characteristics or light transmission characteristics change according to the supplied electric energy, the organic EL elements that require excitation by recombination of carriers are used. Light-emitting elements that do not require excitation (for example, inorganic LED elements), light valve elements that change light transmission characteristics according to supplied electric energy (for example, liquid crystal elements), and the like can be used.

In the above-mentioned embodiments, a bottom emission type organic EL device was described as an example, but it can also be applied to a top emission type organic EL device. The pixel electrode of a top-emission organic EL device is made of a metal material with high reflectivity such as Al or Cr. However, in order to improve hole injection, it is desirable to form ITO (indium tin oxid) and IZO (registered Trademark, indium zinc oxide) and other transparent conductive materials.

In the above-mentioned embodiment, the case when the temperature of the print heads 2 and 31 rises is described. However, when the temperature falls, such as when used in a cold place, due to the thermal expansion coefficients of the light source array 4, the lens array 5, and the spacer member 6, When distortion occurs, the distortion can be absorbed by the second adhesive 13b, 14b or the liquid, so there is no need to worry about the printing head 2, 31 tilting into an arc shape.

In addition, in the above-mentioned embodiment, the adhesives 13, 14 are composed of two types of adhesives, such as the first adhesives 13a, 14a and the second adhesives 13b, 14b (13c, 13d, 14c, 14d). However, the adhesives 13 and 14 may be composed of two or more types of adhesives. At this time, one of the plurality of adhesives is used as the first adhesive, that is, as the space between the element substrate 7 and the spacer member 6 of the light source array 4 and the distance between the spacer member 6 and the lens array 5 are always kept at predetermined intervals. The gap, or the gap between the light source array 4 and the lens array 5 is fixed by an adhesive, and all the adhesives may have the same refractive index and light transmittance.

In the above-mentioned embodiment, the case where the 1st adhesive 13a, 14a is the same type was demonstrated. However, the present invention is not limited thereto, and the first adhesive may be a different type of adhesive if it functions as an adhesive for fixing and has the same refractive index and light transmittance.

Furthermore, in the above-mentioned first embodiment, at one end (right side in FIG. direction), apply the respective first adhesives 13a, 14a, or at the central part in the longitudinal direction of the element substrate 7 of the light source array 4, the lens array 5 and the isolator member 6, across the short side of the print head 2 The first adhesive 13a, 14a is applied substantially in the entire direction. However, the position where the first adhesive 13a, 14a is applied is not limited to these, and any position may be used as long as it is each bonding surface.

In addition, in the second embodiment described above, the first adhesive is applied across the width direction (short side direction) of the print head 31 at one end portion (the right side in FIG. 8 ) of the light source array 4 and the lens array 5 . 13a, or the first adhesive 13a is applied across the width direction (short side direction) of the print head 31 at the center of the element substrate 7 of the light source array 4 and the lens array 5 in the longitudinal direction. However, the position where the first adhesive 13a, 14a is applied is not limited to these, and any position may be used as long as it is each bonding surface.

In addition, in the above-mentioned embodiment, the occupied area of the second adhesive 13b, 14b (13c, 13d, 14c, 14d) is set to be smaller than the occupied area of the first adhesive 13a, 14a on each adhesive surface. large area. However, the present invention is not limited thereto, and the occupied area of the first adhesive 13a, 14a may be set larger than the occupied area of the second adhesive 13b, 14b (13c, 13d, 14c, 14d). However, compared with the case where the occupied area of the second adhesive 13b, 14b (13c, 13d, 14c, 14d) is large, the distortion caused by the difference in the thermal expansion coefficient of the light source array 4, the lens array 5, and the spacer member 6 is absorbed. Decrease in ability. That is, the occupied area of the second adhesive 13b, 14b (13c, 13d, 14c, 14d) on each bonding surface is larger, and the ability to absorb deformation is improved more, while the second adhesive 13b, 14b (13c, 13d , 14c, 14d) the smaller the occupied area, the lower the ability to absorb distortion.

In the above-mentioned embodiment, the case where the thermal expansion coefficient of the spacer member 6 or the thermal expansion coefficient of the lens array 5 is larger than the thermal expansion coefficient of the light source array 4 will be described. However, the present invention is not limited thereto, and the same effects as those of the present embodiment can be produced even when the coefficients of thermal expansion of the components (light source array 4, isolator member 6, and lens array 5) are different.

third embodiment

Here, the prior art that forms the basis of the present invention will be described. FIG. 10 is a perspective view schematically showing a part of a conventional image forming apparatus. In this image forming apparatus, a condensing lens array 140 is arranged between a light-emitting panel 120 provided with an EL element array and a photoreceptor drum 110, and a light-transmitting lens array 140 is arranged between the light-emitting panel 120 and the condensing lens array 140. Transient isolator 170. As described above, as the converging lens array 140 , there is, for example, SLA (Self Focusing Lens Array) available from Nippon Panglass Co., Ltd. (Selfoc/SELFOC is a registered trademark of Nippon Panglass Co., Ltd.).

FIG. 11 is a perspective view schematically showing the condensing lens array 140 . The condensing lens array 140 has a plurality of distributed refractive index lenses 141 arranged in one direction in a zigzag pattern in two rows. Each distributed refractive index lens 141 is a graded-refractive-index optical fiber formed with a low refractive index on the central axis and a higher refractive index as the distance from the central axis increases. For the positive image of the image on the light-emitting panel 120 . The images obtained by the plurality of distributed refractive index lenses 141 constitute one continuous image on the photoreceptor drum 110 .

FIG. 12 is a cross-sectional view of the converging lens array 140 cut along a plane perpendicular to the direction in which the distributed refractive index lenses 141 are arranged (hereinafter referred to as "X direction"). As shown in the figure, the optical distances of the condensing lens array 140 include an object-side working distance (Lo), an image-side working distance (Li), and a conjugate length (TC). In order to sufficiently improve the optical characteristics (such as sharpness) of imaging, the photoreceptor drum 110 and the light-condensing lens array 140 are arranged at an interval (Di ) coincides with Li, and the light emitting panel 120 and concentrating lens array 140 are arranged such that the distance (Do) between the light emitting surface Q in the light emitting panel 120 and the light incident surface S2 of the concentrating lens array 140 coincides with Lo.

FIG. 13 is a schematic side view showing a part of a conventional image forming apparatus. As shown in FIG. 13 , Li and Lo of the condensing lens array 140 generally deviate in the X direction. For example, when focusing on the first position (x1), second position (x2), and third position (x3) arranged in order in the X direction, Li[x1], Li[x2], and Li[x3] at each position ] are different from each other, and Lo[x1], Lo[x2], and Lo[x3] of each position are different from each other. Specifically, Li[x1]<Li[x3]<<Li[x2], Lo[x1]<Lo[x3]<<Lo[x2].

As can be seen from the above examples, the deviations of Li and Lo in the X direction can be nonlinear. The imaging plane P, the light exiting plane S1 , the light incident plane S2 and the light emitting plane Q are respectively flat in the X direction. Therefore, it is difficult to arrange the photoreceptor drum 110 and the condenser lens array 140 such that the full lengths of the Di and Li condenser lenses 140 match with high precision, or to arrange the light emitting panel 120 and the condenser lens array 140 so that the Do and Li Lo coincides with high precision over the entire length of the condensing lens array 140 . Therefore, in the conventional image forming apparatus, there is a possibility that the optical characteristics of imaging may vary greatly in the X direction.

FIG. 14 is a graph showing the characteristics of the imaging radius R with respect to Di in a conventional image forming apparatus. The imaging radius R is the radius of the image of the EL element formed on the imaging plane P. As shown in FIG. The smaller the imaging radius R is, the higher the optical properties of the imaging are. The characteristic line C1 shows the characteristic of the position (position in the X direction) where the difference between Do and the ideal interval (Bo) matching Lo is zero. When 1/2 of the maximum value of the difference between Lo and Bo is a (a > 0), the characteristic line C2 shows the characteristics of the position where the difference between Do and Bo is a (the position in the X direction), and the characteristic line C3 shows Do and Bo The difference of is characteristic of a position twice as large as a (position in the X direction).

From the relative positions of the characteristic lines C1-C3, it can be known that the smaller the difference between Do and Bo, the smaller the imaging radius R is. In addition, it can be seen from the respective shapes of the characteristic lines C1 to C3 that the smaller the difference between Di and the ideal interval (Bi) coincident with Li, the smaller the imaging radius R is. For example, on the characteristic line C1, when the difference between Di and Bi is 0 (point T1), the imaging radius R (r1) is smaller than the imaging radius R (r2) when the difference between Di and Bi is b (each point T2), r2 is smaller than the imaging radius R(r3) when the difference between Di and Bi is twice b (each point T3). Wherein, b>0.

When 1/2 of the maximum value of the difference between Li and Bi is b, the maximum variation width (W1) of the imaging radius R of the conventional image forming apparatus is the difference between r1 and r4. r4 is the imaging radius R of point T4 where the difference between Di and Bi is twice b, and the difference between Do and Bo is twice a. The optical characteristics of the image formed by the conventional image forming apparatus may have large variations in the X direction because W1 is too large. The third and fourth embodiments solve this problem.

Next, an electro-optical device 1A according to a third embodiment of the present invention will be described. In the electro-optical device 1A, the spacer is a layer transverse to the optical axis of the distributed-refractive-index lens, in which a plurality of members having different refractive indices from each other are arranged in one direction. Hereinafter, it will describe in detail.

First, the configuration of the electro-optical device 1A will be described.

FIG. 15 is a plan view of the electro-optical device 1A, and FIG. 16 is a side view (front view) of the electro-optical device 1A. The electro-optic device 1A includes a light-emitting panel (electro-optic panel) 120 , a converging lens array 140 , and a light-transmitting spacer 80 sandwiched between the light-emitting panel and the concentrating lens array 140 . The light-emitting panel 120 has a light-transmitting element substrate 122, a plurality of EL elements 121 formed on the element substrate 122, and a sealing body 123 covering these EL elements 121, and light from each EL element 121 passes through the element substrate 122 side. The light emerges from the exit surface S3.

Each EL element 121 is an electro-optical element whose luminescence characteristics change according to the supplied electric energy, specifically, it has a luminescent layer which is excited to emit light by recombination of injected carriers, and a pair of electrodes sandwiching the luminescent layer. An organic EL element that emits light at the voltage between the pair of electrodes. Among these pair of electrodes, the electrode on the element substrate 122 side is a transparent electrode such as ITO (Indium Tin Oxide). Wiring for supplying a driving voltage to each EL element 121 is provided on the light emitting panel 120 . It should be noted that circuit elements (such as TFTs (Thin Film Transistors)) for supplying driving voltages to the respective EL elements 121 may also be provided on the light emitting panel 120 .

The element substrate 122 is a flat plate made of a light-transmitting material such as glass or transparent plastic, and has a refractive index of n ₂ . The EL elements 121 are arranged in two rows in a zigzag shape on the element substrate 122 , and the plane passing through these element substrates 122 becomes the light emitting surface Q. The sealing body 123 is mounted on the element substrate 122, cooperates with the element substrate 122, isolates the EL element 121 from external air, especially moisture and oxygen, and suppresses its deterioration.

The light-condensing lens array 140 transmits a part of the light incident on its light incident surface S2, emits from its light exit surface S1, has the function of transmitting the light advancing from the light emitting panel 120, and can form an image on the light emitting surface Q ( A plurality of distributed refractive index lenses 141 of the positive image of the image on the light emitting panel 120 . The light incident surface S2 and the light emitting surface S3 of the light emitting panel 120 face each other. The electro-optical device 1A is arranged such that the distance (Di) between the light exit surface S1 and the imaging surface P coincides with the working distance (Li) on the image side of the condensing lens array 140 .

The distributed refractive index lenses 141 are arranged in two rows in a zigzag shape in the X direction, and overlap the region of the light emitting panel 120 where the EL elements 121 are formed. The images obtained by the plurality of distributed refractive index lenses 141 constitute one continuous image. It should be noted that the arrangement patterns of the EL elements 121 and the distributed refractive index lenses 141 are not limited to the one shown in the figure, and may be single row or more than three rows, and other appropriate patterns may be used.

The isolator 80 is filled between the light-emitting panel 120 and the concentrating lens array 140, so that the distance between the two is the same layer of equal thickness, extending across the optical axis of each refractive index distribution lens 141, and made of glass or A plurality of rectangular parallelepiped members 81 to 83 formed of transparent plastic and connected in the X direction transmit light passing through the light emitting panel 120 . In the surface of the isolator 80, the entire area of the surface on the side of the light-emitting panel 120 is in contact with the light-emitting surface S3 of the light-emitting panel 120, and the entire area of the light-incident surface S2 of the light-condensing lens array 140 is in contact with the side of the light-emitting lens array 140. surface contact.

The plurality of members 81 to 83 are in contact with the light exit surface S3 of the light emitting panel 120 and the light incident surface S2 of the condensing lens array 140 . The refractive index of the member 82 is n ₃ , and the refractive indices of the member 81 and the member 83 sandwiching the member 82 are both n ₁ . That is, in the spacer 80 , a plurality of members having different refractive indices are continuous in the X direction. Therefore, the optical distance between the light emitting surface Q and the light incident surface S2 varies in the X direction.

n ₁ to n ₃ , the thickness of the spacer 80 , and the area occupied by each of the members 81 to 83 in the X direction (the occupied area of each member 81 to 83 ) are based on the working distance (Lo) on the object side of the converging lens array 140 , decided to satisfy expression (1).

$\mathrm{<span\; class="notranslate">\; Lo</span>}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

In Expression (1), m is the number of layers between the light emitting face Q and the light incident face S2. In this embodiment, each of the isolator 80 and the element substrate 122 constitutes one layer. _ni and d _i are the refractive index and thickness of the i-th layer.

Usually, the refractive index (n ₂ ) of the element substrate 122 is determined according to the specifications that the light emitting panel 120 should satisfy. In addition, the thickness of the spacer 80 is the same in the X direction. Therefore, the refractive index (n ₃ ) of the member 81 and the member 83, the refractive index (n ₁ ) of the member 82, and the occupied area of each member 81 to 83 are determined according to the position in the X direction. Regarding them, specifically, as shown in FIG. 16 , it is determined that a member 81 formed of a material with a relatively high refractive index (n ₁ ) occupies the vicinity of the first position (x1), and is formed of a material with a relatively high refractive index (n ₁ ). The member 83 occupies the vicinity of the third position (x3), and the member 82 formed of a material having a relatively low refractive index (n ₃ ) occupies the vicinity of the second position (x2). Therefore, if comparing FIG. 13 and FIG. 16, it can be seen that the deviation between the light-emitting surface Q and the surface of the light-emitting surface Q separated from the light incident surface S2 of the light-condensing lens array 140 by an ideal interval (Bo) consistent with Lo can be suppressed to a small amount. . Bo is the distance between the light emitting surface Q and the light incident surface S2 when the optical distance between the light emitting surface Q and the light incident surface S2 matches Lo.

FIG. 17 is a graph showing the characteristics of the imaging radius R with respect to Di of an image forming apparatus using the electro-optical device 1A as an optical head. The imaging radius R is the radius of the image of the EL element formed on the imaging plane P. As shown in FIG. The smaller the imaging radius R, the higher the optical properties of the imaging. Among the characteristic lines C1 to C6 , the characteristic lines C1 to C3 are the same as those shown in FIG. 13 , and the characteristic lines C4 to C6 represent the characteristics of the electro-optical device 1A.

The characteristic line C4 shows the characteristics of the position where the difference between Do and Bo is 0 (the position in the X direction), and the characteristic line C5 shows that when 1/2 of the maximum value of the difference between Lo and Bo is g (g>0), Do and Bo The characteristic of the position where the difference of Bo is g (position in the X direction), the characteristic line C6 shows the position where the difference between Do and Bo is twice g when the maximum value of 1/2 of the difference between Lo and Bo is g (X direction and position). The characteristic line C4 is exactly the same as the characteristic line C1.

As described above, in the electro-optical device 1A, the deviation between the surface away from Bo from the light incident surface S2 of the converging lens array 140 and the light emitting surface Q is suppressed to be small. Therefore, the maximum value of the difference between Do and Bo is smaller than that of the conventional image forming apparatus. That is, g<a. Therefore, as shown in FIG. 17, the density of characteristic lines C4 to C6 is higher than the density of characteristic lines C1 to C3, and the maximum variation width (W2 ) is smaller than W1. It should be pointed out that W2 is the difference between r1 and r5, and r5 is the imaging radius R of point T5 where the difference between Di and Bi is twice b, and the difference between Do and Bo is twice g.

As described above, the electro-optical device 1A has: the light emitting panel 120; the distributed refractive index lenses 141 that transmit the light going forward from the light emitting panel 120 and can form a positive image of the image on the light emitting panel 120 are arranged in one direction more than one. A concentrating lens array 140 that forms a continuous image by the image obtained by a plurality of refractive index distribution type lenses 141; over the isolator 80. In addition, in the spacer 80 , a plurality of members (the member 81 and the member 82 , or the member 82 and the member 83 ) having different refractive indices from each other are connected in the X direction. Therefore, according to the electro-optic device 1A, the optical distance between the light emitting panel 120 and the converging lens array 140 can be made different although the distance between the light emitting panel 120 and the converging lens array 140 is the same in the X direction. In addition, in the electro-optical device 1A, the arrangement of the members 81 to 83 and the refractive index of each member are appropriately determined according to Lo of the condensing lens array 140 . Therefore, according to the electro-optical device 1A, it is possible to reduce variation in optical characteristics of imaging in the X direction.

Manufacturing method of the third embodiment

Next, a method of manufacturing the electro-optical device 1A of the third embodiment will be described. Various methods are considered as a method of manufacturing the electro-optical device 1A. Here, the first manufacturing method and the second manufacturing method are listed.

First manufacturing method of the third embodiment

In the first manufacturing method, the light emitting panel 120 and the spacer 80 are first manufactured. In manufacturing the light-emitting panel 120, a light-transmitting flat plate having a refractive index _n2 is used as the element substrate 122, and EL elements 121 are arranged in two rows in a zigzag shape on the flat plate. In the manufacture of the isolator 80, Lo of the condensing lens array 140 is measured first. In this measurement, only air exists between the light source and the condensing lens array 140, the relative position of the light source and the condensing lens array 140 is variable, and the relative position of the condensing lens array 140 and the imaging plane is fixed. In this process, across the entire length of the condensing lens array 140, the distance between the light emitting surface and the condensing lens array 140 is repeated based on the radius of the imaging of the light emitted from the light source and transmitted through the condensing lens array 140 becomes the smallest. Set as Lo's job.

In the manufacture of the separator 80 , the respective refractive indices, dimensions, and arrangement of the members 81 to 83 are determined based on the measured Lo, and then the members 81 to 83 are joined. Specifically, the refractive index of member 81 and member 83 is determined as n ₁ , the refractive index of member 82 is determined as n ₃ , and the occupied area of each member 81 to 83 is determined, so that when joining members 81 to 83, in one direction, There is a member 82 between the member 81 and the member 83, and when the one direction coincides with the X direction, the member 81 occupies the vicinity of the first position (x1), the member 82 occupies the vicinity of the second position (x2), and the member 83 occupies the third position (x3) near.

Next, as shown in FIG. 18 , the spacer 80 is bonded to the light emitting panel 120 . This bonding is performed in such a way that the entire area of one of the widest surfaces of the isolator 80 is in contact with the light emitting surface S3 of the light emitting panel 120, and the entire area of the area of the light emitting panel 120 where the EL element 121 is formed is in contact with the widest surface S3 of the light emitting panel 120. The wide surfaces overlap, and the one direction coincides with the arrangement direction of the EL elements 121 . Next, as shown in FIG. 19 , the condenser lens array 140 is bonded to the spacer 80 . This joining is carried out in such a manner that the entire area of the light incident surface S2 of the light-condensing lens array 140 is in contact with the other widest surface of the isolator 80, and the refractive index distributed lens 141 of the light-condensing lens array 140 is in contact with the other widest surface. The arrangement direction (X direction) coincides with the one direction, and each distributed refractive index lens 141 overlaps with a region of the light emitting panel 120 where the EL elements 121 are formed.

Next, the relative positions of the light emitting panel 120, the spacer 80, and the condensing lens array 140 are fixed. The fixing method is arbitrary. For example, the side surface of the isolator 80 can be bonded to the light-emitting panel 120 and the concentrating lens array 140, or the light-emitting panel 120 and the concentrating lens array 140 can be placed on the side of the isolator 80. In the box, the light emitting panel 120, the spacer 80, and the converging lens array 140 are housed and fixed.

Second manufacturing method of the third embodiment

In the second manufacturing method, the light emitting panel 120 and the member 82 are manufactured first. In the manufacture of the member 82 , first, Lo of the converging lens array 140 is measured, and then, according to the measured Lo, the respective refractive indices, dimensions, and arrangement of the members 81 to 83 are determined to form the member 82 .

Next, as shown in FIG. 20 , a spacer 80 is bonded to the light emitting panel 120 , and a converging lens array 140 is bonded to the spacer 80 . Next, as shown in FIG. 21 , between the light-emitting panel 120 and the converging lens array 140 , a cured transparent adhesive having a refractive index of _n1 is injected and cured to form members 81 and 83 . It should be noted that a guide frame may be used to prevent the fluid adhesive before hardening from flowing out and to solidify the adhesive into a predetermined shape.

Fourth Embodiment

Next, an electro-optical device 1B according to a fourth embodiment of the present invention will be described. In this electro-optical device 1B, the isolator has a plurality of layers transverse to the optical axis of the distributed refractive index lens, and in at least two of these layers, a plurality of members having different refractive indices are arranged in one direction. Hereinafter, differences from the electro-optical device 1A of the third embodiment will be described in detail.

First, the configuration of the electro-optical device 1B will be described.

FIG. 22 is a side view (front view) of the electro-optical device 1B. The electro-optical device 1B differs from the electro-optical device 1A in that an isolator 90 is provided instead of the isolator 80 . The isolator 90 is a part filled between the light-emitting panel 120 and the concentrating lens array 140 to make the intervals between the two uniform, and consists of a light-transmitting multilayer extending across the optical axis of each distributed refractive index lens 141. 91 to 93 are configured to transmit the light traveling from the light emitting panel 120 .

Layer 91 is an isolator body of equal thickness sandwiched between layers 92 and 93, and is formed of glass or transparent plastic. The refractive index of layer 91 is n ₁ . The entire surface of the light-emitting panel 120 side of layer 91 is bonded to the entire surface of layer 92 on the converging lens array 140 side, and the entire surface of layer 91 on the converging lens array 140 side is bonded to the light emitting surface of layer 93. Full bonding of the faces on one side of the panel 120 .

The layer 92 is an adhesive layer of equal thickness sandwiched between the layer 91 and the light emitting panel 120 , and is composed of a plurality of cuboid members 921 to 923 connected in the X direction. The member 922 is formed of a transparent adhesive having a refractive index of _n6 , and the members 921 and 923 are each formed of a transparent adhesive having a refractive index of _n5 . That is, in the layer 92, members having different refractive indices are connected in the X direction.

The layer 93 is an adhesive layer of equal thickness sandwiched between the layer 91 and the converging lens array 140 , and is composed of a plurality of cuboid members 931 to 933 connected in the X direction. The member 931 is formed of a transparent adhesive having a refractive index of _n5 , and the member 932 is formed of a transparent adhesive having a refractive index of _n6 . That is, in layer 93 , members having different refractive indices are connected in the X direction. The distribution of the refractive index of these members is completely different from the distribution of the refractive index of the plurality of members included in the layer 92 . That is, the two distributions are different from each other.

According to the Lo of the converging lens array 140, _n2 , _n4 - _n6 , the thicknesses of the layers 91-93, and the areas occupied by the members 921-923, 931-932 in the X direction (each member 921-923, 931 ~932 occupied area) is determined to satisfy the expression (1). n ₂ is usually determined according to the specifications that the light-emitting panel 120 should meet. The refractive index (n ₄ ) of layer 91 and the thicknesses of layers 91 to 93 are the same in the X direction, so n ₅ and n are determined according to the position in the X direction. _6. Occupied areas of the components 921-923, 931-932.

As can be seen from the above description, the electro-optical device 1B produces the same effects as those of the electro-optical device 1A. In addition, when any one of the layer 92 or the layer 93 does not exist, the optical distance between the light emitting surface Q and the light incident surface S2 is diversified by using a member with a refractive index of _n5 and a member with a refractive index of _n6 . However, in the electro-optic device 1B, the isolator 90 has a layer 92 including members with different refractive indices and a layer 93 including members with different refractive indices, and the distribution of the refractive indices of the plurality of members included in layer 92 and the layer The distribution of the refractive index of the 93 members is different, so more optical distance can be obtained. This is a shift in optical properties that contributes to further reducing imaging in the X direction.

Manufacturing method of the fourth embodiment

Next, a method of manufacturing the electro-optical device 1B of the fourth embodiment will be described. Various methods are considered as a method of manufacturing the electro-optical device 1B. Here, one manufacturing method is listed.

First, the light emitting panel 120 and the layer 91 are manufactured. In the manufacture of the layer 91, the Lo of the converging lens array 140 is first measured, and then the refractive index and thickness of the layer 91, the refractive index and the occupied area of the members 921 to 923, 931, and 932 are determined according to the measured Lo, and then A layer 91 having a refractive index _n4 is formed.

Next, as shown in FIG. 23, a transparent adhesive with a refractive index of _n6 after hardening is applied to the area occupied by the member 922 on the light emitting surface S3 of the light-emitting panel 120, and the adhesive is compressed until the light-emitting The thickness determined by the panel 120 and the layer 91 is hardened in this state. That is, the layer 91 is bonded to the light emitting panel 120 . The hardened adhesive becomes member 922 . Next, as shown in FIG. 24, a transparent adhesive having a cured refractive index of _n5 is injected between the light-emitting panel 120 and the layer 91, and cured. The hardened adhesive becomes member 921 and member 923 .

Next, as shown in FIG. 25 , the occupied area of the member 932 on the surface of the converging lens array 140 side of the layer 91 is coated with a transparent adhesive having a refractive index of _n6 after hardening, and the bonding is performed. The agent is compressed to a thickness determined by the layer 91 and the converging lens array 140, and hardens in this state. That is, the condenser lens array 140 is bonded to the layer 91 . The hardened adhesive becomes member 932 . Next, as shown in FIG. 26, a cured transparent adhesive having a refractive index of _n5 is injected between the layer 91 and the converging lens array 140 and cured. The hardened adhesive becomes the member 931 .

It should be noted that in the step of applying or injecting the adhesive, a guide frame may be used to prevent the fluid adhesive before hardening from flowing out and to solidify the adhesive into a desired shape. In addition, in order to reliably fit the compressed adhesive, a solid space ensuring material may be contained in the compressed adhesive. As the gap securing material, it is desirable to have a light-transmitting, spherical shape, and a material having almost the same refractive index as the surrounding adhesive.

In the fourth embodiment described above, layers 92 and 93 have materials with different refractive indices, but this may be modified so that either one of layers 92 and 93 has materials with different refractive indices. In addition, the third embodiment described above may be modified so that isolators 80 include members not related to transmission of light from light emitting panel 120 . Similarly, the fourth embodiment described above may be modified so that at least one of the layer 92 and the layer 93 includes a member not involved in the transmission of light from the light emitting panel 120 . The above-described embodiment may be modified so that the separator includes three or more layers having members having different refractive indices.

In the third and fourth embodiments described above, the bottom emission type light emitting panel 120 in which the light emitted from each EL element 121 passes through the element substrate 122 and is emitted from the light emitting panel 120 is used, but it may also be used. A top emission type light-emitting panel that emits light in the opposite direction. That is, the object that transmits light proceeding from the plurality of electro-optical elements may be a sealing body. At this time, the light transmittance of each part is determined so that the light emitted from each EL element and traveling toward the sealing body side is not blocked.

In addition, in the above-mentioned third and fourth embodiments, as a plurality of electro-optical elements whose light emission characteristics or light transmission characteristics change according to the supplied electric energy, excitation by recombination of carriers is used as an essential element. Organic EL elements, but it is also possible to use light-emitting elements that do not require recombination of carriers (such as inorganic EL elements), excitation of light-emitting elements that are not necessary (such as inorganic LEDs), and light transmission characteristics that change according to the supplied electric energy. A light valve element (such as a liquid crystal element).

Fifth Embodiment

The conventional image forming apparatuses described with reference to FIGS. 10 to 14 have the following problems. In light-emitting elements such as EL elements constituting the light-emitting panel 120 , as shown in FIG. 27 , there is variation in brightness (brightness or power). A0 in the figure represents the brightness of the light emitted from the light emitting element, and A1' represents the brightness on the imaging surface of the image support or the like. The aforementioned variation is due to, for example, manufacturing variation of the light emitting element. If an electrostatic latent image is formed in such a state where the brightness of the light-emitting element varies, a difference in gradation or uneven gradation will appear in the finally developed image, and a beautiful picture cannot be obtained. Therefore, in order to eliminate the deviation of the luminance of the above-mentioned light-emitting element, as in JP-A-2006-289721, it is proposed to provide a function (for example, adjustment of current and voltage, Adjustment of luminescence time, etc.).

However, if the above-mentioned functions are provided on the driving circuit, not only the size of the driving circuit will be increased, which is not conducive to the miniaturization of the light-emitting panel, but also has the problem of increasing the cost. In addition, in order to correct the variation in brightness of the light-emitting element, it is necessary to repeatedly measure the brightness of the light-emitting element, adjust the current and voltage, or adjust the emission time. Therefore, a lot of labor and time are required, and the production cost increases inefficiently. The fifth and sixth embodiments solve this problem.

FIG. 28 is a plan view showing a fifth embodiment of the electro-optical device of the present invention, and FIG. 29 is a side view showing the electro-optical device. The electro-optic device IC of the illustrated example has a light emitting panel (electro-optic panel) 220 , a converging lens array 140 , and a light transmission member (isolator) 30 interposed between the light emitting panel and the concentrating lens array 140 . The light-emitting panel 220 has a light-transmitting element substrate (array substrate) 222 , a plurality of light-emitting elements 221 as electro-optic elements formed on the element substrate 222 , and a sealing body 223 covering the light-emitting elements 221 . The light from each light emitting element 221 is emitted from the light emitting surface (in the figure, upper surface) S13 of the element substrate 222 .

Each light-emitting element 221 is an electro-optical element whose light-emitting characteristics change according to the supplied electric energy, specifically, it has a light-emitting layer excited to emit light by recombination of injected carriers, and a pair of electrodes sandwiching the light-emitting layer, An organic EL element that emits light according to a voltage applied between the pair of electrodes. Of the pair of electrodes, the electrode on the element substrate 222 side is a transparent electrode such as ITO (Indium Tin oxide). Wiring for supplying a driving voltage to each light emitting element 221 may also be provided on the light emitting panel 220 . In addition, a circuit element (such as a TFT (Thin Film Transistor)) for supplying a driving voltage to each light emitting element 221 may be provided on the light emitting panel 220 .

The element substrate 222 is a flat plate formed of a light-transmitting material such as glass or transparent plastic. On the element substrate 222, the light emitting elements 221 are arranged in a zigzag shape in one direction, and the plane passing through these light emitting elements 221 becomes a light emitting surface. Q. The sealing body 223 is mounted on the element substrate 222, cooperates with the element substrate 222, and isolates the light-emitting element 221 from external air, especially moisture and oxygen, and suppresses its deterioration.

The light-condensing lens array 140 transmits a part of the light incident on its light-incident surface S12, emits from its light-emitting surface S11, and has the function of transmitting the light advancing from the light-emitting panel 220 to form an image on the light-emitting surface Q (light emission). A plurality of distributed refractive index lenses 141 of the positive image of the image on the panel 220 . The light incident surface S12 of the condensing lens array 140 and the light emitting surface S13 of the light emitting panel 220 face each other, and the distance between the light emitting surface Q and the light emitting surface S13 is approximately equal to the sum of the thickness of the element substrate 222 and the thickness of the light transmitting member 30 . In the above-mentioned electro-optic device 1C, the distance between the light exit surface S11 and the imaging surface P is arranged so as to correspond to the working distance on the image side of the light-condensing lens array 140 .

The distributed refractive index lenses 141 are arranged in a zigzag shape in one direction (X direction) as shown in FIG. 28 , and overlap the region of the light emitting panel 220 where the light emitting elements 221 are formed. The images obtained by the plurality of distributed refractive index lenses 141 constitute one continuous image. It should be noted that the arrangement patterns of the light emitting elements 221 and the distributed refractive index lenses 141 are not limited to the one shown in the figure, and may be arranged in a single row or more than three rows, or arranged in other appropriate patterns.

The light-transmitting member 30 exists between the light-emitting panel 220 and the condenser lens array 140, keeps the distance between them constant, and guides the light from the light-emitting panel 220 to the condenser lens array 140. The optical axis direction of the lens 141 is configured as one or more layers. In addition, the light transmission member 30 extends transversely to the optical axis of each distributed refractive index lens 141. In this embodiment, it is formed of glass or transparent plastic and has an overall substantially rectangular parallelepiped shape that is long in the X direction. The light emitted from the light emitting panel 220 is transmitted and guided to the condensing lens array 140 . In the surface of the light-transmitting member 30, the entire area of the surface on the side of the light-emitting panel 220 is in contact with the light-emitting surface 13 of the light-emitting panel 220, and the entire area of the light-incident surface S12 of the light-condensing lens array 140 is in contact with the light-emitting lens array. 140 side surface contact.

In this embodiment, the light transmittance of the light-transmitting member 30, more specifically, the light transmittance of the lens 141 in the direction of the optical axis is set in the direction in which the lens 141 and the light emitting element 221 are arranged (FIG. 28, X direction in Fig. 29) is different. In the embodiment shown in the figure, the light transmission member 30 is constituted as one layer, and the light transmission member 30 constituted by the one layer is divided into a plurality of parts 30a to 30c in the longitudinal direction (the X direction), so that The light transmittance of each part 30a-30c differs. Accordingly, it is possible to eliminate variations in the brightness of the light-emitting elements 221 that are a plurality of electro-optic elements or the sum of the elements 221 and the light-condensing lens array 140 .

Specifically, the brightness of the light emitted from the plurality of light emitting elements 221, as shown in A1 in FIG. When there is a deviation in the brightness, the light transmittance of the light transmission member 30 is set so as to be almost inversely proportional to the brightness. In this embodiment, as shown in FIG. 30 , the central part of the arrangement direction of the light-emitting elements 221 is bright, and the brightness of both ends is lower than that of the central part. The light transmittance of 30c is set to a relatively high light transmittance a ₁ , and the light transmittance of the central portion 30b is set to a lower light transmittance a ₂ .

Accordingly, in FIG. 29 , the light from the light-emitting element 221 of light brightness _IX1 passes through the element substrate 222 and the part 30a (or 30c) of the light-transmitting member 30 and the converging lens array 140 and is on the image carrier. The light brightness I _Y1 and the brightness I _X2 of the light projected on the imaging surface of 10 etc. from the light-emitting element 221 pass through the element substrate 222 and the part 30b of the light-transmitting member 30 and the concentrating lens array 140 and The brightness I _Y2 of the light projected and imaged on an imaging surface such as the support body 10 can be almost equal. Expressions (2) to (4) express this relationship.

I _Y1 = a ₁ b s I _x1 ...... (2)

I _Y2 ＝a ₂ b s I _x2 ......(3)

I _Y1 = I _Y2 ... (4)

b in the expressions (2) and (3) is the light transmittance of the element substrate 222 , and s represents the light utilization rate of the condensing lens array.

As described above, according to the present embodiment, by varying the light transmittance of the light transmission member 30 in the direction in which the lenses 141 are arranged, it is possible to correct variations in brightness of the light emitting elements 221 . As in the above-mentioned embodiment, the light transmittance in the arrangement direction of the lenses 141 of the light-transmitting member 30 is gradually different (changed) according to the brightness of the light-emitting element 221, and the above-mentioned A1 in FIG. 30 can be corrected. The deviation of the brightness of the light-emitting element, A2 in FIG. 30 represents the brightness after correction, that is, the imaging in the state where the light-transmitting member 30 exists between the light-emitting panel 220 and the concentrating lens array 140 as shown in FIG. 29 Brightness on face P. It can be seen that the variation in brightness of A2 is smaller than that of A1.

In the above-described embodiment, the light transmittance of the light transmission member 30 is changed stepwise, but it may be changed continuously. In addition, in the above-described embodiment, the brightness variation of the light-emitting element 221 is corrected, but if there is a variation in transmittance or brightness in the converging lens array 140, the light-emitting element 221 and the converging lens will The difference in brightness added by the array 140 makes the light transmittance of the light transmission member 30 different. As the light transmission member 30, if the light transmittance is as high as possible, the brightness after correction can be made brighter.

As mentioned above, the electro-optical device 1C includes: a light-emitting panel 220 as an electro-optic panel having a plurality of light-emitting elements 221 as electro-optic elements; A plurality of distributed refractive index lenses 141 of the positive image of the image are arranged in one direction, and the images obtained by a plurality of distributed refractive index lenses 141 form a concentrating lens array 140 of a continuous image; Between the panel 220 and the condensing lens array 140 is a light transmission member 30 that guides the light emitted from the light emitting panel 220 to the condensing lens array 140 . The light transmittance of the light-transmitting member 30 is different in the arrangement direction of the lenses 141, so that the brightness of the light-emitting element 221 or the elements 221 including the light-condensing lens array 140 can be easily corrected. the brightness deviation.

Manufacturing method of the fifth embodiment

Next, taking the electro-optical device of the fifth embodiment as an example, the method of manufacturing the electro-optical device of the present invention will be specifically described. Various methods are conceivable as a method of manufacturing the electro-optical device 1C of the above-mentioned embodiment. Here, the first manufacturing method and the second manufacturing method are listed.

First manufacturing method of the fifth embodiment

In the first manufacturing method, the light emitting panel 220 and the light transmission member 30 are first manufactured. In the manufacture of the light-emitting panel 220, a light-transmitting flat plate is used as the element substrate 222. On this plate, as shown in FIG. Arranged in Z shape. On the other hand, when manufacturing the light-transmitting member 30, the brightness of the light emitted from the plurality of light-emitting elements 221 or the brightness of the light emitted from the plurality of light-emitting elements 221 and transmitted through the condensing lens array 140 is measured first. The brightness of the light. In these measurements, measurements are performed sequentially or collectively along the direction in which the light emitting elements 221 or the lenses 141 of the condensing lens array 140 are arranged (the X direction).

It should be noted that when measuring the brightness of the light emitted from the plurality of light emitting elements 221, it can be measured that the light emitted from the plurality of light emitting elements 221 passes through the members constituting the light emitting panel 220 (in the above embodiment, the element Brightness behind the substrate 222). In addition, when measuring the brightness of light emitted from the plurality of light emitting elements 221 and passing through the converging lens array 140, when the light emitting elements 221 and the concentrating lens array 140 are arranged in a predetermined assembled state, Alternatively, both are measured in a state where the lens 141 is arranged to overlap in the optical axis direction. Or measure the brightness of light emitted from a plurality of light-emitting elements 221, the brightness or transmittance or light attenuation rate of light passing through the light-condensing lens array 140, and calculate from the measured results to obtain the Brightness of the light transmitted by the plurality of light emitting elements 221 through the condensing lens array 140 .

Next, based on the above-mentioned measurement results, when there is a shift in the X-direction in the brightness, the light transmittance of the light-transmitting member 30 is varied according to it. As shown in FIG. 29, when the light transmission member 30 is constituted as a single layer, and the light transmittance is changed stepwise in the longitudinal direction (the X direction), the light transmission member 30 in the above-mentioned The longitudinal direction is divided into a plurality of parts 30a-30c, the length dimension and light transmittance of each part 30a-30c are respectively determined, and the parts with the corresponding light transmittance are connected together to form the light-transmitting member 30. In this embodiment, as shown in FIG. 31A , on both sides of the central portion 30b formed of a light-transmitting material with a light transmittance of a ₂ , a glass made of a light-transmitting material with a light transmittance of a ₁ is integrally fixed. Both end portions 30a, 30c form the light transmission member 30 .

Next, the light transmission member 30 is bonded to the light emitting panel 220 as shown in FIG. 31A. This joining is carried out in such a manner that the entire area of one widest surface (lower side of the figure) of the light-transmitting member 30 is in contact with the light-emitting surface S13 of the light-emitting panel 220. The entire area of the region overlaps with the widest surface, and the longitudinal direction of the light transmission member 30 coincides with the arrangement direction of the light emitting elements 221 . Next, as shown in FIG. 31B , a condensing lens array 140 is bonded to the widest surface (upper surface in the figure) of the other side of the light transmission member 30 (the side opposite to the light emitting panel 220 ). This bonding is carried out in such a manner that the entire area of the light incident surface S12 of the light-condensing lens array 140 is in contact with the other widest surface of the light-transmitting member 30, and the refractive index of the light-condensing lens array 140 The arrangement direction (X direction) of the distributed lenses 141 coincides with the longitudinal direction of the light transmission member 30 , and each distributed refractive index lens 141 overlaps the region of the light emitting panel 220 where the light emitting elements 221 are formed.

Finally, the relative positions of the light-emitting panel 220 , the light-transmitting member 30 and the concentrating lens array 140 are fixed. The fixing method is arbitrary. For example, the side surfaces (upper and lower surfaces) of the light-transmitting member 30 can be bonded to the light-emitting panel 220 and the light-condensing lens array 140, or the light-emitting panel 220 and the light-condensing lens array 140 can be placed next to each other. The light-emitting panel 220 , the light-transmitting member 30 , and the condensing lens array 140 are accommodated in a case on the side of the light-transmitting member 30 .

Second manufacturing method of the fifth embodiment

In the second manufacturing method, the manufacturing of the light-emitting panel 220 and the measurement of the variation are the same as those in the first manufacturing method, and the light transmittance of the light-transmitting member 30 is varied according to the measurement results. As described above, the light transmission member 30 composed of one layer is divided into a plurality in the longitudinal direction, and the length dimension and light transmittance of each part are determined in the same manner as described above. Moreover, in the second manufacturing method, first, the central portion 30b is formed of a light-transmitting material with a light transmittance of _a2 , and the light-transmitting material is directly placed on the light-emitting panel 220 to form the central portion 30b, Alternatively, additionally formed materials are placed on the light emitting panel 220 .

FIG. 32A shows that the central part 30b of the light transmittance _a2 formed into a substantially rectangular parallelepiped is placed on the light-emitting panel 220, and the condensing lens array 140 is placed thereon. The portion 30a is bonded to the light emitting panel 220 and the converging lens array 140 in close contact with each other. Next, as shown in FIG. 32B , between the light-emitting panel 220 and the light-condensing lens array 140 on both sides of the portion 30b, a transparent light-transmitting material that _doubles as the light transmittance after curing of the adhesive is injected into the space. , which hardens to form portions 30a and 30c. It should be noted that a guide frame or the like may also be used in order to prevent the fluidity of the translucent material from flowing out and to shape the portions 30a and 30c into desired shapes.

Sixth Embodiment

Next, an electro-optical device according to a sixth embodiment will be described. In the electro-optical device 1D of the present embodiment, a multilayer structure in which a plurality of light transmission members are stacked in the optical axis direction of the lens is formed, and at least one of these layers, in this embodiment, two layers The light transmittance is different. Hereinafter, differences from the fifth embodiment will be mainly described in detail.

33 is a side view (front view) of an electro-optical device according to a sixth embodiment of the present invention. The electro-optical device 1D of this embodiment differs from the fifth embodiment ( FIG. 29 ) in that the light transmission member 30 is composed of one layer, whereas the light transmission member 30 of this embodiment is composed of multiple layers. . In the illustrated form, the light transmission member 30 is composed of three layers 31 to 33 . The light-transmitting member 30 is filled between the light-emitting panel 220 and the condensing lens array 140 so that the intervals between the two are the same, and the light-transmitting member 30 extends from the optical axis transverse to each distributed refractive index lens 141. A plurality of layers 31 to 33 are configured to transmit light traveling from the light emitting panel 220 .

The layer 31 is an intermediate layer of equal thickness existing between the layers 32 and 33, and is formed of glass or transparent plastic in this embodiment, and the light transmittance of the layer 31 is _a3 , which is kept constant over the entire length. The entire surface of the light-emitting panel 220 side of the layer 31 is bonded to the entire surface of the layer 32 on the converging lens array 140 side, and the entire surface of the layer 31 on the converging lens array 140 side is bonded to the entire surface of the layer 31. The entire surface of the light emitting panel 220 side surface of the layer 33 is bonded.

The layer 32 is a layer of equal thickness also serving as an adhesive sandwiched between the layer 31 and the light-emitting panel 220, and is composed of a plurality of rectangular parallelepiped parts 32a to 32c connected in the X direction. The portion 32b is formed of a translucent material that also serves as a transparent adhesive with a light transmittance of _a5 , and the portions 32a and 32c are each formed of a translucent material that also serves as a transparent adhesive with a light transmittance of _a4 .

The layer 33 is a layer of equal thickness also serving as an adhesive sandwiched between the layer 31 and the converging lens array 140, and is composed of a plurality of rectangular parallelepiped parts 33a to 33b connected in the X direction. The portion 33a is formed of a translucent material serving as a transparent adhesive having a light transmittance of _a6 , and the portion 33b is formed of a translucent material serving as a transparent adhesive having a light transmittance of _a7 .

The X-direction lengths and light transmittances of the portions 32a to 32c and 33a to 33b of the layer 32 and the layer 33 are the same as described above. The luminance added by the condensing lens array 140 is appropriately set. Accordingly, the luminance in the assembled state of the light-emitting panel 220, the light-transmitting member 30, and the condensing lens array 140 as shown in FIG. become certain.

Use a mathematical formula to illustrate this relationship. In FIG. 33 , the light emitted from the light-emitting element 221 with predetermined brightness _IX passes through the element substrate 222, the multilayer light-transmitting member 30, and the converging lens array 140, and the brightness of the light when forming an image on the imaging surface is as follows: degree is I _Y , I _Y can be expressed as in expression (5).

${\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; Y</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\underset{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Pi;</span>}}}{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

是来自发光元件221的光按顺序透过的构件的各构件的光透过率的积。S表示聚光性透镜阵列的光利用率。表达式(5)中的光透过率i_j能按表达式(6)那样表示。i _j in the expression (5) is the transmittance of the member through which the light from the light emitting element 221 passes,

is the product of the light transmittance of each member through which the light from the light emitting element 221 transmits sequentially. S represents the light utilization efficiency of the condensing lens array. The light transmittance i _j in Expression (5) can be expressed as in Expression (6).

i _j ＝e ^-αt ......(6)

In the expression (6) is the absorption coefficient, which is a value inherent to the substance, and t is the thickness of the substance.

α can be expressed as in Expression (7).

α＝4πk·λ ^-1 ......(7)

k in the expression (7) is an attenuation coefficient, which is a value inherent to a substance, and λ represents the wavelength of light.

In the present embodiment, by locally varying the light transmittance between the layers 32 and 33 of the light-transmitting member 30, the brightness I _Y of the light emitted from all the light-emitting elements 221 when forming an image on the imaging surface becomes almost constant. . According to this, even if there is variation in the brightness of the light emitting elements 221 or light from the light emitting elements 221 including the condensing lens array 140 , the brightness in the X direction can be kept almost constant.

As can be seen from the above description, in this embodiment, the same effect as that of the fifth embodiment can be obtained. In addition, as in the present embodiment, by forming the light transmission member 30 with a plurality of layers 31 to 33, dividing the two or more layers into a plurality of parts, and making the light transmittance of each part different, various types of light can be obtained. The light transmittance distribution can more finely correct the aforementioned variation in brightness.

It should be noted that, in the above embodiment, the two layers are set according to the brightness of the light emitted from the plurality of light emitting elements 221 or the brightness of the light emitted from the plurality of light emitting elements 221 and transmitted through the condensing lens array 140. 32 and 33 have different light transmittance distributions, but only one or three or more layers may have different light transmittance distributions. In addition, when the light transmittance of the light transmission member 30 is different according to the brightness of the light emitted from the plurality of light emitting elements 221 and transmitted through the condensing lens array 140, the brightness of the light emitted from the plurality of light emitting elements 221 Variations in brightness can be corrected in any layer (for example, layer 33 ), and variations in brightness, light transmittance, or light absorption of converging lens array 140 can also be corrected in other layers (for example, layer 32 ). In addition, the number of said layers, the number of divided layers, and the number of divided parts can be changed suitably.

Manufacturing method of the sixth embodiment

Next, taking the electro-optic device 1D of the sixth embodiment as an example, a manufacturing method when the light-transmitting member 30 is formed in multiple layers will be described. Various methods are conceivable for the method of manufacturing the electro-optical device of the sixth embodiment, but one method is listed here.

First, the light emitting panel 220 and the layer 31 are manufactured. The layer 31 is formed into a predetermined size and shape using a translucent material such as glass or transparent plastic, for example. As the light-transmitting material, a material with as high a light transmittance as possible can be used so that the brightness is not lowered. In the present embodiment, as described above, the light transmittance is a ₃ and becomes constant over the entire length.

Then, as shown in FIG. 34A, at the installation position of the portion 32b on the light emitting surface S13 of the light-emitting panel 220, a light-transmitting material that also serves as a transparent adhesive with a light transmittance after curing of a ₅ is applied, and the The light-transmitting material is sandwiched between the light-emitting panel 220 and the layer 31, and compressed to a predetermined thickness. It is hardened in this state, a portion 32b is formed as shown in FIG. 34B , and the light emitting panel 220 and the layer 31 are bonded through the portion 32b. Next, as shown in FIG. 34B, between the light-emitting panel 220 and the layer 31 on both sides of the portion 32b, a light-transmitting material with a light transmittance of _a4 after curing is injected, and it is cured. , as shown in FIG. 34C, a portion 32a and a portion 32c are formed.

Next, as shown in FIG. 34C , on the surface (upper surface) of the layer 31 opposite to the light-emitting panel 220, a transparent adhesive that also serves as a transparent adhesive with a light transmittance of _a7 after hardening for forming the portion 33b is applied. The optical material is compressed to a predetermined thickness by sandwiching the light-transmitting material between the layer 31 and the light-condensing lens array 140 . In this state, it is cured to form a portion 33 b as shown in FIG. 34D , and the bonding layer 31 and the converging lens array 140 are passed through this portion 33 b. Next, between the layer 31 on the side of the portion 33b and the converging lens array 140, inject a light-transmitting material that also serves as a transparent adhesive with a light transmittance of _a6 after hardening, and harden it to form Part 33a will suffice.

In the step of applying or injecting the translucent material serving as the binder, in order to prevent the outflow of the fluid translucent material before hardening, and to form the part formed of the translucent material into a predetermined The shape of the guide frame, etc. can also be used. In addition, when forming the part by compressing the translucent material, in order to form the part with a predetermined thickness with high precision, there may be other objects such as a spherical shape with a predetermined radius between the members compressing the translucent material. The material for securing the interval of the required shape, or is mixed with the above-mentioned light-transmitting material. It is desirable that the gap ensuring material has light transmittance and has light transmittance substantially equal to that of the light transmittance material.

As described above, there are multiple layers 31 to 33 of light-transmitting members 30 between the light-emitting panel 220 and the converging lens array 140 , thereby enabling simple and reliable manufacture of the electro-optic device shown in FIG. 33 . As described above, when changing the number of layers of the light-transmitting member 30 or the number of layers and the arrangement of parts having different light transmittances, the above-described process can also be appropriately changed accordingly.

In the above-mentioned fifth and sixth embodiments, the light emitted from each light emitting element 221 passes through the element substrate 222, and the light emitting panel 220 of the bottom emission type is emitted from the light emitting panel 220, but it is also possible to use the opposite. A top emission type light-emitting panel that emits light in the direction of the light. That is, the object through which light proceeding from a plurality of electro-optic elements (light-emitting elements) passes may be the sealing body 223 . At this time, in order not to block the light emitted from each light-emitting element and traveling toward the sealing body side, a light-transmitting material is used as the material of each part.

In the above-mentioned fifth and sixth embodiments, as a plurality of electro-optical elements whose luminescence characteristics or light transmittance are changed according to supplied electric energy, organic EL devices which require excitation by recombination of carriers are employed. However, it is also possible to use light-emitting elements that do not require recombination of carriers (such as inorganic EL elements), do not require excitation as a necessary light-emitting element (such as inorganic LED elements), and transmit light according to the supplied electric energy. Light valve elements with variable characteristics (such as liquid crystal elements).

image forming device

Each electro-optical device according to the embodiment of the present invention can be used as a line optical head for writing a latent image on an image carrier in an image forming apparatus using electrophotography. As examples of the image forming apparatus, there are a printer, a printing section of a copier, and a printing section of a facsimile.

35 is a longitudinal sectional view of the image forming apparatus according to the embodiment of the present invention. This image forming apparatus is a tandem-type color image forming apparatus using a system with an intermediate transfer body. In this image forming apparatus, four optical heads 10K, 10C, 10M, and 10Y having the same structure are respectively arranged at exposure positions of four photoreceptor drums (image carriers) 110K, 110C, 110M, and 110Y having the same structure. The optical heads 10K, 10C, 10M, and 10Y are electro-optical devices according to embodiments of the present invention.

As shown in the figure, a driving roller 1121 and a driven roller 1122 are provided in the image forming apparatus, and an endless intermediate transfer belt 1120 is wound around these rollers 1121 and 1122 and rotates around the rollers 1121 and 1122 as indicated by arrows. Although not shown, a tension applying member such as a tension roller that applies tension to the intermediate transfer belt 1120 may be provided.

Around the intermediate transfer belt 1120 , four photoreceptor drums 110K, 110C, 110M, and 110Y having photosensitive layers are arranged at predetermined intervals from each other. The subscripts K, C, M, and Y mean that they are used to form black, cyan, magenta, and yellow visible images, respectively. The same applies to other components. The photoreceptor drums 110K, 110C, 110M, and 110Y are rotationally driven in synchronization with the driving of the intermediate transfer belt 1120 .

Around each photoreceptor drum 110 (K, C, M, Y), a corona charger 111 (K, C, M, Y), an optical head 10 (K, C, M, Y), and a developer 114 are arranged. (K, C, M, Y). The corona chargers 111 (K, C, M, Y) uniformly charge the outer peripheral surfaces of the corresponding photoreceptor drums 110 (K, C, M, Y). The optical head 10 (K, C, M, Y) writes an electrostatic latent image on the charged outer peripheral surface of the photoreceptor drum. Each optical head 10 (K, C, M, Y) is arranged such that the array direction of the plurality of EL elements 121 is along the generatrix (main scanning direction) of the photoreceptor drum 110 (K, C, M, Y). Writing of an electrostatic latent image is performed by irradiating the photoreceptor drum with light from the plurality of EL elements 121 . The developing units 114 (K, C, M, Y) attach toner, which is a developer, to the electrostatic latent image to form a visible image, that is, a video image, on the photoreceptor drum.

Visible images of black, cyan, magenta, and yellow formed by such 4-color monochromatic development forming positions are sequentially transferred to the intermediate transfer belt 1120, and superimposed on the intermediate transfer belt 1120, resulting in a visible color image. picture. Four primary transfer corotrons (transfer units) 112 (K, C, M, Y) are arranged inside the intermediate transfer belt 1120 . The primary transfer corotrons 112 (K, C, M, Y) are arranged in the vicinity of the photoreceptor drums 110 (K, C, M, Y) The visible image is attracted electrostatically, and the visible image is transferred on the intermediate transfer belt 1120 passing between the photoreceptor drum and the primary transfer corotron.

Sheets 102 to be finally imaged are conveyed one by one from the paper feed cassette by the pickup roller 103 to the nip between the intermediate transfer belt 1120 and the secondary transfer roller 126 that are in contact with the drive roller 1121 Holding point (nip). The full-color visible image on the intermediate transfer belt 1120 is uniformly secondarily transferred to one side of the paper 102 by the secondary transfer roller 126 , and fixed on the paper 102 through the fixing part, namely the fixing roller pair 126 . Then, the paper 102 is discharged by the paper discharge roller 128 to a paper discharge cassette formed on the upper part of the apparatus.

Fig. 36 is a longitudinal sectional view of another image forming apparatus according to the embodiment of the present invention. This image forming apparatus is a full-color image forming apparatus using a rotary development system with an intermediate transfer body system. In the image forming apparatus shown in FIG. 36 , a corona charger 168 , a rotary developing unit 161 , an optical head 167 , and an intermediate transfer belt 169 are provided around a photoreceptor drum (image carrier) 165 . The optical head 167 is an electro-optical device according to an embodiment of the present invention.

The corona charger 168 uniformly charges the outer peripheral surface of the photoreceptor drum. The optical head 167 writes an electrostatic latent image on the charged outer peripheral surface of the photoreceptor drum 165 . The optical head 167 is an electro-optical device or an electro-optical device of a modified example thereof, and is provided such that the array direction of the plurality of EL elements 121 is along the generatrix (main scanning direction) of the photoreceptor drum 165 . Writing of an electrostatic latent image is performed by irradiating the photoreceptor drum with light from the plurality of EL elements 121 .

The developing unit 161 is a drum in which four developing units 163Y, 163C, 163M, and 163K are arranged at an angular interval of 90°, and is rotatable counterclockwise around an axis 161 a. The developing units 163Y, 163C, 163M, and 163K respectively supply yellow, cyan, magenta, and black toners to the photoreceptor drum 165 , and attach the toner as a developer to the electrostatic latent image to form a visible image on the photoreceptor drum 165 . Visual image.

The endless intermediate transfer belt 169 is wound around the driving roller 1170a, the driven roller 1170b, the primary transfer roller 166 and the tension roller, and rotates around these rollers in the direction indicated by the arrow. The primary transfer roller 166 electrostatically attracts the visible image from the photoreceptor drum 165 , and transfers the visible image to the intermediate transfer belt 169 passing between the photoreceptor drum and the primary transfer roller 166 .

Specifically, in the first turn of the photoreceptor drum 165, an electrostatic latent image for a yellow (Y) image is written by the optical head 167, a visible image of the same color is formed by the developer 163Y, and then transferred to the intermediate transfer. Ribbon 169. In addition, in the next turn, an electrostatic latent image for a cyan (C) image is written by the optical head 167, and a visible image of the same color is formed by the developer 163C, and is transferred to the intermediate transfer belt while superimposed on the visible image of yellow. 169. Then, when the photoreceptor drum 9 rotates four times in this way, visible images of yellow, cyan, magenta, and black are sequentially superimposed on the intermediate transfer belt 169 , and as a result, a full-color image is formed on the transfer belt 169 . When forming images on both sides of paper as the object of final image formation, on the intermediate transfer belt 169, the visible image of the same color on the surface and the back is transferred, and then on the intermediate transfer belt 169, the next image on the surface and the back is transferred. In the form of the visible image of the color, a full-color visible image is obtained on the intermediate transfer belt 169 .

A paper transport path 174 through which paper passes is provided in the image forming apparatus. The paper is taken out one by one from the paper feed cassette 178 by the pick-up roller 179, is advanced on the paper conveyance path 174 by the conveying roller, and passes through the nip between the intermediate transfer belt 169 and the secondary transfer roller 171 in contact with the driving roller 1170a. Hold on. The secondary transfer roller 171 uniformly electrostatically attracts a full-color visible image from the intermediate transfer belt 169, and transfers the visible image to one side of the paper. The secondary transfer roller 171 approaches or moves away from the intermediate transfer belt 169 by a clutch not shown. The secondary transfer roller 171 is in contact with the intermediate transfer belt 169 when transferring a colored visible image onto the paper, and is separated from the secondary transfer roller 171 when superimposing and developing on the intermediate transfer belt 169 .

The paper on which the image has been transferred as described above is conveyed to the fixing unit 172, and passes between the heating roller 172a and the pressing roller 172b of the fixing unit 172, whereby the visible image on the paper is fixed. The fixed paper is pulled in by the discharge roller pair 176 and advances in the arrow F direction. During double-sided printing, after most of the paper passes through the pair of discharge rollers 176, the pair of discharge rollers 176 rotates in the opposite direction, and as indicated by arrow G, is guided to the transport path 175 for double-sided printing. Then, the visible image is transferred to the other side of the paper by the secondary transfer roller 171 , the fixing process is performed by the fuser 172 again, and the paper is discharged by the paper discharge roller pair 176 .

According to each of the image forming apparatuses described above, since the electro-optical device according to the embodiment of the present invention is used as the optical head, a high-quality image can be formed.

The image forming apparatuses to which any one of the electro-optical devices according to the embodiments of the present invention can be applied have been mentioned above, but any one of the electro-optical devices according to the embodiments of the present invention can also be applied to other electrophotographic image forming devices. Such an image Forming means is within the scope of the invention. For example, an image forming apparatus of a type that directly transfers a visible image from a photoreceptor drum without using an intermediate transfer belt, or an image forming apparatus that forms a monochrome image.

Claims (12)

1. electro-optical device, have: a direction on substrate is arranged the array of source of a plurality of light-emitting components; To on a described direction, arrange a plurality of lens arras from the lens element that the emergent light of described light-emitting component is held volume imaging in the picture load; And according at first light-transmitting member and second light-transmitting member that dispose with mode that described array of source contacts with described lens arra between described array of source and the described lens arra,

Described first light-transmitting member is connected configuration with described second light-transmitting member on a described direction;

At least one is different in elastic modelling quantity, refractive index, light transmission rate for described first light-transmitting member and described second light-transmitting member.

2. electro-optical device according to claim 1 is characterized in that:

The elastic modelling quantity of described second light-transmitting member of the modular ratio of described first light-transmitting member is low, and the area of described first light-transmitting member is bigger than the area of described second light-transmitting member.

3. electro-optical device according to claim 1 is characterized in that:

The refractive index height of described second light-transmitting member of the refractive index ratio of described first light-transmitting member, from the emergent light of described light-emitting component outgoing, see through described first light-transmitting member and hold in described picture load by described lens arra volume imaging light the imaging radius with see through described second light-transmitting member and hold in described picture load by described lens arra volume imaging light the imaging radius about equally.

4. electro-optical device according to claim 1 is characterized in that:

The light transmission rate of described first light-transmitting member is than the light transmission rate height of described second light-transmitting member, from the emergent light of described light-emitting component outgoing, see through described first light-transmitting member and from the lightness of the light of described lens arra outgoing with see through described second light-transmitting member and about equally from the lightness of the light of described lens arra outgoing.

5. electro-optical device according to claim 1 is characterized in that:

Described first light-transmitting member and described second light-transmitting member are binding agents.

6. electro-optical device, have: a direction on substrate is arranged the array of source of a plurality of light-emitting components; To on a described direction, arrange a plurality of lens arras from the lens element that the emergent light of described light-emitting component is held volume imaging in the picture load; Be configured in first light-transmitting member between described array of source and the described lens arra; According at second light-transmitting member and the 3rd light-transmitting member that dispose with mode that described array of source contacts with described first light-transmitting member between described array of source and described first light-transmitting member; And according at the 4th light-transmitting member that disposes with mode that described first light-transmitting member contacts with lens arra between described first light-transmitting member and the described lens arra,

Described second light-transmitting member is connected configuration with described the 3rd light-transmitting member on a described direction;

At least one is different in elastic modelling quantity, refractive index, light transmission rate for described second light-transmitting member and described the 3rd light-transmitting member.

7. electro-optical device according to claim 6 is characterized in that:

The elastic modelling quantity of described the 3rd light-transmitting member of the modular ratio of described second light-transmitting member is low, and the area of described second light-transmitting member is bigger than the area of described the 3rd light-transmitting member.

8. electro-optical device according to claim 6 is characterized in that:

The refractive index height of described the 3rd light-transmitting member of the refractive index ratio of described second light-transmitting member, from the emergent light of described light-emitting component outgoing, see through described second light-transmitting member and hold in described picture load by described lens arra volume imaging light the imaging radius with see through described the 3rd light-transmitting member and hold in described picture load by described lens arra volume imaging light the imaging radius about equally.

9. electro-optical device according to claim 6 is characterized in that:

The light transmission rate of described second light-transmitting member is than the light transmission rate height of described the 3rd light-transmitting member, from the emergent light of described light-emitting component outgoing, see through described second light-transmitting member and from the lightness of the light of described lens arra outgoing with see through described the 3rd light-transmitting member and about equally from the lightness of the light of described lens arra outgoing.

10. electro-optical device according to claim 6 is characterized in that:

Described first light-transmitting member is glass or plastics, and described second light-transmitting member, described the 3rd light-transmitting member and described the 4th light-transmitting member are binding agents.

11. an image processing system has:

The picture load is held body;

Make described picture load hold the charged charged device of body;

To advance and carry on a shoulder pole the charged face of holding body to described picture from described array of source and shine, form the described electro-optical device of claim 1 of sub-image through the light of described lens arra;

Adhere to toner at described sub-image, thereby hold the developer that body forms visible image in described picture load; With

Hold the transfer printing device that body is transferred to described visible image on other objects from described picture load.

12. an image processing system has:

The picture load is held body;

Make described picture load hold the charged charged device of body;

To advance and carry on a shoulder pole the charged face of holding body to described picture from described array of source and shine, form the described electro-optical device of claim 6 of sub-image through the light of described lens arra;

On described sub-image, adhere to toner, thereby hold the developer that body forms visible image in described picture load; With

Hold the transfer printing device that body is transferred to described visible image on other objects from described picture load.

Images