JP2011185969A - Electrooptical device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrooptical device for enhancing luminance on the front face of a scattering film or in the neighborhood of it and preventing rainbow-like coloring, and to provide electronic equipment including the electrooptical device. <P>SOLUTION: The electrooptical device includes an electrooptical material between a pair of substrates, a scattering film layer 16 on one substrate side, and a reflector 14 on the other substrate side. The scattering film layer 16 transmits incident light, diffuses light reflected from the reflector 14, and is arranged so that an incident light side is a minus side when one side for a reference face orthogonal to the surface is the minus side and the other side is a plus side, and a plurality of the scattering films 16A (16B) formed to have diffusion characteristics being a prescribed angle of the plus side from a prescribed angle of the minus side are formed to be laminated when the diffusion angle range makes zero angles of a normal direction of the scattering film. In the plurality of the scattering films 16A, 16B, respective diffusion characteristics are formed substantially the same. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electro-optical device and an electronic apparatus.

  A liquid crystal display device, which is one of electro-optical devices, is characterized by being lightweight and thin, and is therefore widely used for various applications including displays for portable information terminals. A liquid crystal display device performs display by changing the transmission intensity of light by driving liquid crystal molecules with an effective voltage of several volts, but the liquid crystal itself is a non-light emitting substance and requires some other light source. The power for the light source is much larger than the driving power. Therefore, by providing a reflective liquid crystal display device that has a reflector on the lower side of the liquid crystal display element to display using ambient light, it is possible to realize a display device that consumes the original characteristics of liquid crystal with extremely low power consumption. Become.

  However, since the reflective liquid crystal display device displays using ambient light, there is a problem that brightness can be obtained only in the regular reflection direction of light incident on the display device. Under such a background, a scattering film (directional scattering film) made of a special diffusion film that scatters light from a specific angle and transmits light from other angles has little viewing angle dependency. A reflective liquid crystal display device (reflective liquid crystal display element) having characteristics has been proposed (see, for example, Patent Documents 1 to 8).

Japanese Patent No. 3209718 Japanese Patent No. 3219377 Japanese Patent No. 3219733 Japanese Patent No. 3238887 Japanese Patent No. 3351945 Japanese Patent No. 3480260 Japanese Patent No. 3570419 Japanese Patent No. 3760675

  However, the scattering film according to the patent document has a problem that the brightness at the front is low and the film becomes dark. For example, when a scattering film having a diffusion range of 0 ° to 45 ° is used, the diffusion characteristics of this scattering film are usually trapezoidal as shown in the graph of FIG. 11 showing the correlation between the diffusion angle and the luminance. Approximate to both legs and upper base line. That is, when light is incident at, for example, 30 degrees with respect to the normal line of the scattering film, the incident light hardly depends on the incident angle and is 0 with respect to the normal line of the scattering film as shown in FIG. It diffuses in an angular range of about 45 degrees or more and 45 degrees or less. However, strictly speaking, the intensity (luminance) of light diffused at 0 degrees or 45 degrees is low. Therefore, the luminance at the front (0 degree), which is a position where the possibility of being observed is high, becomes low.

  For such a problem, it is conceivable to use a scattering film whose diffusion range is expanded to the minus side (for example, minus 10 degrees or minus 5 degrees). However, when this scattering film is applied to a reflective liquid crystal display device, as shown in FIG. 12, the scattering film F is in the range of minus 5 degrees to 0 degrees, which is near the front (0 degree, the normal method of the scattering film). In addition to diffusion at the time of incidence on the light, diffusion may occur at the time of emission from the scattering film F after being reflected by the reflector 55. As a result, as shown in FIG. 13, the luminance near the front (particularly in the range of minus 5 degrees to 0 degrees) is lowered and darkened.

In addition, the scattering film is not diffused when light is incident on the scattering film F as shown in FIG. By arranging, it is considered that the luminance at the front or in the vicinity thereof is improved.
However, in that case, when the light is reflected by the reflector and then emitted from the scattering film, the diffused light may interfere with each other, and a rainbow-like coloring may be visually recognized in the display image.
Further, when there are a plurality of light sources or when the incident light is diffused light, the possibility of blurring in the display image increases.

  The present invention has been made in view of the above circumstances, and provides an electro-optical device that increases the luminance at or near the front of the scattering film and prevents rainbow-like coloring, and an electronic apparatus equipped with the electro-optical device. The purpose is that.

  In order to achieve the above object, an electro-optical device according to the present invention is provided with an electro-optical material between a pair of substrates arranged opposite to each other, and a scattering film layer is provided on one of the pair of substrates. A reflector is provided on the other side of the pair of substrates, and the scattering film layer transmits incident light, diffuses the light reflected from the reflector, and When one side is a minus side and the other side is a plus side with respect to a reference plane orthogonal to the surface, the incident light is arranged to be a minus side, and the diffusion angle range of the scattering film is When the normal direction is 0 degree, a plurality of scattering films formed with diffusion characteristics having a predetermined angle on the positive side from the predetermined angle on the negative side are formed by laminating a plurality of the plurality of scattering films. Scattering of Lum is characterized in that each of the diffusion properties is formed to be substantially the same.

According to this electro-optical device, as the scattering film layer, when one side is a minus side and the other side is a plus side with respect to a reference plane orthogonal to the surface of the scattering film layer, the light incident side is a minus side. And a plurality of scattering films formed by diffusing the diffusion angle range so that the diffusion angle range is a predetermined angle on the positive side from a predetermined angle on the negative side. Since the film is stuck in the direction of diffusing only at the time of emission after being reflected by the reflector, the luminance at the front or near the scattering film layer is greatly improved.
In addition, since a plurality of the scattering films are laminated, the light reflected by the reflector and emitted from the scattering films is diffused for each scattering film, thereby increasing the degree of diffusion. As a result, interference caused by the diffused light hardly occurs, and the rainbow-like coloring is prevented from being visually recognized in the display image.

In the electro-optical device, it is preferable that a thickness of the one substrate is 0.2 mm or less.
Thus, if the thickness of one substrate on the side closer to the scattering film is 0.2 mm or less, the distance of the optical path to the scattering film of the light reflected from the reflector is shortened. Therefore, even when there are a plurality of light sources or when the incident light is diffused light, it is possible to prevent the display image from being blurred.

Further, in the electro-optical device, the scattering film has a diffusion characteristic in a graph showing a correlation between the diffusion angle and the luminance, and the luminance is almost constant, and the correlation between the diffusion angle and the luminance is a first straight line. In the first range to be approximated and on the side where the diffusion angle in the first range is close to 0 degrees, the luminance changes substantially constant, and the correlation between the diffusion angle and the luminance is approximated to a second straight line. It is preferable that the intersection of the first straight line and the second straight line is at a position where the diffusion angle is negative.
If it does in this way, the brightness | luminance of the light which diffuses at 0 degree | times of a scattering film will become 1st range, and will become high. Therefore, the brightness at the front of the scattering film or in the vicinity thereof is improved.

In the electro-optical device, it is preferable that an organic EL front light is provided outside the scattering film.
In this way, even when there is no external light source such as sunlight or room light, it is possible to perform display using the light of the organic EL front light.
Further, in the electro-optical device, the scattering film has a property of transmitting light incident from the first direction and diffusing light incident from the second direction, and the first direction is the minus direction. The organic EL front light is preferably arranged so that the light is incident on the scattering film from the first direction.

According to another aspect of the invention, an electronic apparatus includes the electro-optical device.
According to this electronic apparatus, as described above, the electro-optical device in which the luminance at the front surface or the vicinity thereof with respect to the scattering film layer is significantly improved and the rainbow-like coloring is prevented from being visually recognized in the display image is provided. Therefore, this electronic device itself has excellent display performance.

1 is a side sectional view schematically showing an embodiment of a liquid crystal display device according to the present invention. (A) and (b) are the principal part enlarged views which show the structure of a scattering film layer typically. (A) (b) is a schematic diagram for demonstrating the effect | action of a scattering film. It is a schematic diagram for demonstrating the effect | action of a scattering film layer. It is a graph which shows the diffusion characteristic of a scattering film. (A) (b) is a schematic diagram for demonstrating the effect | action of a scattering film layer. (A) (b) is a graph which shows the diffusion characteristic of a scattering film. It is a sectional side view which shows typically other embodiment of the liquid crystal display device which concerns on this invention. It is a top view which shows schematic structure of an organic electroluminescent front light. It is a schematic block diagram of the mobile telephone which concerns on the electronic device of this invention. It is a graph which shows the diffusion characteristic of a scattering film. It is a schematic diagram for demonstrating the effect | action of a scattering film. It is a graph which shows the diffusion characteristic of a scattering film.

Hereinafter, the present invention will be described in detail with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.
FIG. 1 is a diagram showing an embodiment of a liquid crystal display device as an electro-optical device of the present invention, and is a side sectional view schematically showing a schematic configuration of the liquid crystal display device.

  In FIG. 1, reference numeral 1 denotes a liquid crystal display device. The liquid crystal display device 1 includes a liquid crystal cell 2. In the liquid crystal cell 2, a liquid crystal layer 12 is filled between a first substrate (one substrate) 10 and a second substrate (the other substrate) 11 that are arranged to face each other, and a transparent electrode 13 is formed on the inner surface of the first substrate 10. And the liquid crystal cell 2 in which the reflector (reflector) 14 is formed on the inner surface of the second substrate 11.

On the first substrate 10 side of the liquid crystal cell 2 on the display side, in order from the first substrate 10, a viewing angle compensation film (retardation plate) 15, a scattering film layer 16, a retardation plate 17, and a polarizing plate are arranged on the outer surface side. 18 is provided.
Based on such a configuration, the liquid crystal display device 1 adopts an ECB (Electrically Controlled Birefringence) mode. However, the liquid crystal display device of the present invention is not limited to the ECB mode, but is a TN (Twisted Nematic) mode, a VAN (Vertical Aligned Nematic) mode, an STN (Super Twisted Nematic) mode, an OCB (Optical Compensated Bend) mode, or the like. Of course, can be adopted. In that case, it is possible to cope with various modes by adding conventionally known components such as a color filter, a polarizing plate, and an electrode that also serves as a reflector.

In the present embodiment, the first substrate 10 and the second substrate 11 constituting the liquid crystal cell 2 are both formed of a glass substrate. In particular, the first substrate 10 is formed of a transparent glass substrate and has a thickness of 0.2 mm or less, for example, 0.2 mm.
The transparent electrode 13 is formed of indium / tin / oxide (ITO) or the like. The reflection plate 14 is made of a metal film formed by depositing, for example, silver on the inner surface of the second substrate 11. The reflective film 14 may be used directly as an electrode, or silver or aluminum may be deposited on a separately formed electrode to function as a reflective film (reflector).

An alignment film (not shown) is formed on the inner surfaces of the transparent electrode 13 and the reflective film 14, and these alignment films are subjected to a known alignment process.
Between the first substrate 10 and the second substrate 11, spacers (not shown) such as beads are arranged between them, and a sealing material (not shown) is provided between the outer peripheral portions of the inner surfaces of the first substrate 10 and the second substrate 11. ing. Then, liquid crystal is filled in a gap surrounded by the first substrate 10 and the second substrate 11 and the sealing material, and a liquid crystal layer 12 is formed.

The viewing angle compensation film (retardation plate) 15 is for ensuring viewing angle characteristics and contrast, and is made of an optical film that functions as a retardation plate such as an NH film or a WV film.
Further, the polarizing plate 18 and the retardation plate 17 constituting the outermost part on the display side are configured so that circularly polarized light is incident on the liquid crystal cell 2 side.

  In this embodiment, the scattering film 16 layer disposed between the retardation film 17 and the viewing angle compensation film 15 is formed by laminating two scattering films 16A and 16B, that is, the scattering film 16A and the scattering film 16B. Has been. These scattering films 16A and 16B are forward scattering films formed so that the diffusion range is a predetermined angle range set in advance, and in this embodiment, the scattering films 16A and 16B are made of the same configuration.

  That is, as the scattering films 16A and 16B, those having a diffusion range in an angle range of minus 5 degrees to plus 45 degrees are used in this embodiment. Here, since the scattering films 16A and 16B have the same configuration as described above, their diffusion characteristics, that is, diffusion ranges are formed to be substantially the same. Therefore, in the present embodiment, the scattering films 16A and 16B both have an angle range of minus 5 degrees to plus 45 degrees.

  However, in the present invention, variation in product characteristics between the scattering films 16A and 16B is allowed. Specifically, between these scattering films 16A and 16B, if the diffusion range is 5% or less, there is no particular problem even if they are different. Therefore, the diffusion range is different within 5% or less. In the present invention, “the plurality of scattering films are formed with substantially the same diffusion characteristics”.

  That is, in the scattering film layer 16 composed of the scattering films 16A and 16B, good visibility can be obtained only in a range where the diffusion ranges of the scattering films 16A and 16B overlap due to the diffusion characteristics. Therefore, the best visibility can be obtained if the diffusion ranges of these scattering films 16A and 16B are completely matched (overlapped). However, if it is in the range of 5% or less as described above, the visibility is only slightly lowered, and there is no practical problem. As such a forward scattering film, for example, Lumisty (trade name) manufactured by Sumitomo Chemical Co., Ltd. is used.

  As shown in FIG. 2A, the scattering films 16A and 16B are formed by alternately laminating a plurality of resin layers (for example, resin layers 50A and 50B) having different refractive indexes, and further, an interface between the resin layers 50A and 50B. 51 is formed to be inclined at a predetermined angle with respect to the front surface (or back surface) of the scattering film 16.

  And these scattering films 16A and 16B are laminated | stacked so that the direction where the said interface 51 inclines may become the same, as shown in FIG.2 (b). That is, the straight lines 51a formed by the interface 51 appearing on the respective upper surfaces (or lower surfaces) are all parallel between the scattering films 16A and 16B. The scattering films 16A and 16B are laminated in a state where the respective resin layers 50A and 50B are shifted from each other, and thus the interface 51 is shifted without being continuous. In addition, about these scattering films 16A and 16B, if the inclination direction is simply aligned and pasted on the viewing angle compensation film 15, the probability that the interface 51 will continue is extremely low. Is done.

  As shown in FIG. 3A, the scattering films 16A and 16B having such a configuration are both from the one side with respect to the reference plane 52 orthogonal to the surface of the scattering film 16A (16B). When light is incident in the same direction (second direction) as the direction in which the light is inclined, the incident light diffuses in the diffusion range when passing through the scattering film 16. Moreover, in the liquid crystal display device 1 of this embodiment, since the reflecting plate 14 (reflector) exists behind the scattering film 16 </ b> A (16 </ b> B), incident light is reflected by the reflecting plate 14 and again passes through the scattering film 16. In this case, the reflected light (emitted light) enters the scattering film 16 in a direction (first direction) intersecting with the direction in which the interface 51 of the scattering film 16 is inclined, so that the reflected light is diffused. It emits as it is without waking up. Therefore, in the state shown in FIG. 3 (a), as schematically shown by the arrows in FIG. 3 (a), diffusion occurs when entering the scattering film 16, but no diffusion occurs when exiting. .

  On the other hand, as shown in FIG. 3 (b), when light is incident on the reference surface 52 perpendicular to the surface of the scattering film 16A (16B) from the other side in a direction crossing the direction in which the interface 51 is inclined, Incident light is incident as it is without being diffused when passing through the scattering film 16. The reflected light (emitted light) reflected by the reflecting plate 14 enters the scattering film 16 in the same direction as the interface 51 of the scattering film 16 is inclined. To spread. Therefore, in the state shown in FIG. 3B, as schematically shown by the arrow in FIG. 3B, diffusion does not occur when entering the scattering film 16, but diffusion occurs when exiting. .

Therefore, in this embodiment, the scattering films 16A and 16B are arranged so that diffusion does not occur when entering the scattering film 16A (16B) and diffusion occurs when exiting, as shown in FIG. The scattering film layer 16 is formed.
That is, in the liquid crystal display device 1 shown in FIG. 1, the virtual reference plane 19 is disposed perpendicular to the surface of the scattering film layer 16 (scattering film 16B), that is, the surface of the polarizing plate 18 parallel thereto. In addition, about this reference | standard surface 19, as shown to Fig.3 (a), (b), this scattering film 16A (of FIG. 2) of resin layer 50A, 50B (refer FIG. 2) which comprises scattering film 16A (16B). 16B) It is arranged so as to be parallel to the length direction of the interface 51 (straight line 51a) on the surface.

  One side of the reference plane 19 is the minus (−) side, and the other side is the plus (+) side. Further, the minus side and the plus side of the scattering film layer 16 (scattering films 16 </ b> A and 16 </ b> B) correspond to the direction of the observer with respect to the liquid crystal display device 1 in this way. That is, in FIG. 1, the observer (observer's viewpoint) P is positioned on the plus (+) side, at 0 degree or in the vicinity thereof. Therefore, the liquid crystal display device 1 is configured such that the plus (+) side is below the display surface of the liquid crystal display device 1 and the minus (−) side is above the display surface. Further, by configuring in this way, the light source (sun, room light, etc.) S is positioned on the minus (−) side opposite to the observer P.

  Under such a configuration, each of the scattering films 16A and 16B is configured to prevent incident light from the minus (−) side where the light source S is disposed with respect to the reference surface 52 shown in FIG. It does not diffuse when incident, but diffuses only when the reflected light is emitted. Further, as described above, since both of the scattering films 16A and 16B have an angle range of minus 5 degrees to plus 45 degrees, the reflected light of light incident from the minus (−) side ( When the light exits the scattering film 16, as shown by an arrow R in FIG. 3B, the light exits within an angle range of minus 5 degrees to plus 45 degrees with respect to the plane 52 a parallel to the reference plane 52. To do.

  Therefore, when light is incident on the scattering film layer 16 formed by laminating the scattering films 16A and 16B from the minus (−) side, the light reflected from the reflecting plate 14 is reflected by the scattering film 16A as shown in FIG. First, it diffuses in an angle range of minus 5 degrees to plus 45 degrees. Further, of the diffused light, the diffused light traveling from the minus (−) side to the plus (+) side is diffused again by the scattering film 16B. Therefore, since the light emitted from the scattering film layer 16 is diffused for each of the scattering films 16A and 16B, the degree of diffusion is increased, and interference due to the diffused light hardly occurs.

  Here, FIG. 5 shows a graph (a graph showing the diffusion characteristics) representing the correlation between the diffusion angle and the luminance for the scattering films 16A and 16B in which the diffusion range is from minus 5 degrees to plus 45 degrees. As shown in the graph of FIG. 5, when light is incident on the reference surface 52 at, for example, 30 degrees, the scattering film 16 is shown in FIG. 5 without depending on the incident angle. Thus, the diffusion range is about minus 5 degrees or more and 45 degrees or less. However, strictly speaking, the brightness of the light diffused at minus 5 degrees or 45 degrees is lowered.

  However, when compared with the scattering film having the diffusion characteristics shown in FIG. 11 and having a diffusion range of 0 degree to plus 45 degrees, the scattering film shown in FIG. 11 is more likely to be observed as described above. While the brightness at the front (0 degree) as the position is low, the scattering film 16 shown in FIG. 5 has a sufficiently high brightness at the front (0 degree). Therefore, the display quality when viewed from the front is sufficiently improved by using such scattering films 16A and 16B. It should be noted that the display quality when viewed from the front in this way is sufficiently improved even in the case of the scattering film layer 16 formed by laminating the scattering films 16A and 16B.

  Further, the light source S is positioned on the minus (−) side as shown in FIG. 1 with respect to the scattering film layer 16 (scattering films 16A and 16B), so that incident light from the light source S is diffused when incident. Since the reflected light reflected by the reflecting plate 14 is diffused only when it exits the scattering film 16, the vicinity of the front surface (particularly in the range of minus 5 degrees to 0 degrees) as shown in FIG. Therefore, when the observer (observer's viewpoint) P is positioned at 0 degree or in the vicinity thereof, the inconvenience that the display becomes dark and is visually recognized is prevented.

  Further, in the liquid crystal display device (electro-optical device) 1 of the present embodiment, since the scattering film layer 16 formed by laminating the scattering films 16A and 16B is provided, the light reflected by the reflecting plate 14 is as described above. By diffusing each scattering film 16A, 16B and increasing the degree of diffusion, interference caused by diffused light hardly occurs. Therefore, it is possible to prevent the rainbow-like coloring from being visually recognized in the display image.

Here, it is considered that the interference phenomenon that occurs when only one scattering film is used is caused by the fact that light slightly out of phase between diffused light exits the same position as it is. When light of the same wavelength overlaps and is strengthened by the interference phenomenon as described above, the color of this wavelength appears on the display screen. In addition, the rainbow-like (rainbow-like) coloring is visually recognized on the display screen because the wavelength of the enhanced light differs depending on the viewing position and viewing angle on the display screen.
On the other hand, in the liquid crystal display device (electro-optical device) 1 according to the present embodiment, the interference caused by the diffused light hardly occurs as described above, so that rainbow-like coloring can be prevented.

  Further, in the liquid crystal display device 1 of the present invention, as described above, the thickness of the first substrate 10 shown in FIG. 1 is formed to be 0.2 mm or less (for example, 0.2 mm). By doing in this way, the distance between the reflecting plate 14 of the liquid crystal cell 2 and the scattering film 16 becomes remarkably short compared with the past. That is, in the related art, the thickness of the first substrate 10 in the liquid crystal cell 2 is about 0.5 mm to 0.6 mm, whereas in the present embodiment, the thickness is 0.2 mm or less. The distance between the reflector 14 and the scattering film layer 16 is also shortened by 0.3 mm or more. A liquid crystal layer 12 and a viewing angle compensation film 15 are disposed between the reflector 14 and the scattering film layer 16. The thickness of the liquid crystal layer 12 is several μm (2 to 4 μm) and the viewing angle. The thickness of the compensation film 15 is several tens of μm (40 to 50 μm) or less, and thus is sufficiently smaller than the thickness (plate thickness) of the first substrate 10.

Thus, by shortening the distance between the reflecting plate 14 and the scattering film layer 16, even when there are a plurality of light sources such as room lights, or when the incident light is diffused light, the scattering film layer 16 is reduced. The display image caused by the emitted light is prevented from being blurred.
That is, when the distance between the reflecting plate 14 and the scattering film layer 16 is long as in the prior art, and thus the optical path is long, a plurality of (two in FIG. 6A) light sources as shown in FIG. The light reflected from the pixel G from S is incident on another part of the scattering film layer 16 again and diffused here, so that a part of each diffused light is observed by the observer P. As a result, the display may be visually recognized in a blurred state.

  On the other hand, the thickness of the first substrate 10 is set to 0.2 mm or less and the distance between the reflecting plate 14 and the scattering film layer 16 is shortened as in the present embodiment, so that each of the plurality of light sources S is used. When the light reflected from the pixel G is incident again on the scattering film layer 16 as shown in FIG. 6B, the reflected light is incident on different positions as shown in FIG. 6B. However, the incident light enters almost the same position. Therefore, blurring in the display image is suppressed.

Here, the results of examining the thickness of the first substrate 10 and the presence or absence of display blur are shown below.
In the configuration shown in FIG. 1, three types of liquid crystal display devices were manufactured using the first substrate 10 having a thickness of 0.6 mm, 0.3 mm, and 0.2 mm, and the others were the same. However, for the scattering film layer 16, only one scattering film 16A was provided as a single layer without stacking the two scattering films 16A and 16B.
When these three types of liquid crystal display devices are driven to perform display, and the presence or absence of blur is visually checked, blur is clearly recognized in the case of using the first substrate 10 having a thickness of 0.6 mm. Slight blur was observed in the case of using the first substrate 10 having a thickness of 0.3 mm, and no blur was observed in the case of using the first substrate 10 having a thickness of 0.2 mm.
Therefore, it was confirmed that the above-described blur can be suppressed by setting the thickness of the first substrate 10 to 0.2 mm or less.

  In the above embodiment, the scattering films 16A and 16B have a diffusion range of minus 5 degrees to plus 45 degrees, but the present invention is not limited to this, and the diffusion angle range is on the minus side. It can be used as long as it has a diffusion characteristic that becomes a predetermined angle on the plus side from a predetermined angle. Specifically, those having a diffusion range in which the predetermined angle on the minus side is about -1 to -10 degrees and the predetermined angle on the plus side is about +40 degrees to +50 degrees are preferably used.

 However, even in this case, in the graph in which the diffusion characteristic indicates the correlation between the diffusion angle and the luminance, the luminance is substantially constant, and the correlation between the diffusion angle and the luminance is approximated to the first straight line. And a second range in which the luminance changes substantially constant and the correlation between the diffusion angle and the luminance is approximated by a second straight line on the side where the diffusion angle in the first range is close to 0 degrees. It is desirable to use the one where the intersection of the first straight line and the second straight line is at a position where the diffusion angle is negative.

  That is, the diffusion characteristic represented by the correlation between the diffusion angle and the luminance does not have a clean trapezoidal shape as shown in the graphs of FIGS. 11 and 5 schematically shown. For example, the diffusion range is from minus 5 degrees to plus 45. The graph shown in FIG. FIG. 7A shows the correlation between the diffusion angle and the luminance when light is incident at an incident angle of 30 degrees. As shown in FIG. 7A, although a peak appears in the total reflection area (diffuse angle is 30 degrees) with respect to an incident angle of 30 degrees, it has a substantially trapezoidal shape (both trapezoid legs and upper base) in other areas. Approximate to a line.

Therefore, a range in which the luminance is substantially constant and the correlation between the diffusion angle and the luminance is approximated to the first straight line, which is the upper base portion of the substantially trapezoid excluding the peak, is defined as a first range E1. Further, on the side where the diffusion angle in the first range E1 is close to 0 degrees, the luminance is changed to be substantially constant, which is one leg portion of the substantially trapezoid, and the correlation between the diffusion angle and the luminance is the second. A range approximated by a straight line is defined as a second range E2.
And as shown in FIG.7 (b), it is using the scattering film in which the diffusion angle of the intersection Q of the said 1st straight line L1 and the said 2nd straight line L2 in each of these ranges becomes a minus. desirable.
If it does in this way, the brightness | luminance of the light which diffuses at 0 degree | times of a scattering film will become high by becoming the 1st range E1. Therefore, compared with the conventional scattering film shown in FIG. 11, the brightness at the front of the scattering film or in the vicinity thereof is significantly improved.

  As described above, in the liquid crystal display device 1 of the present embodiment, as the scattering film layer 16, one side with respect to the reference plane 19 orthogonal to the surface of the scattering film layer 16 is the minus side, and the other side. When the positive side is the positive side, the light incident side is arranged to be the negative side, and the diffusion angle range is formed to have a diffusion characteristic in which the predetermined angle on the positive side is changed from the predetermined angle on the negative side. Since a plurality of scattering films 16A (16B) are laminated and the scattering films 16A and 16B are attached in a direction that diffuses only at the time of emission after being reflected by the reflector 14, the scattering films The brightness at or near the front of the layer 16 is greatly improved, and the display quality is excellent.

Moreover, since the scattering film layer 16 formed by laminating the scattering films 16A and 16B is provided, the light reflected by the reflecting plate 14 is diffused for each of the scattering films 16A and 16B, thereby increasing the degree of diffusion. Interference caused by light hardly occurs. Therefore, it is possible to prevent the rainbow-like coloring from being visually recognized in the display image.
Furthermore, since the thickness of one of the substrates on the side closer to the scattering film is 0.2 mm or less, the distance of the optical path from the light reflected from the reflection plate 14 to the scattering film 16 is shortened. Therefore, even when there are a plurality of light sources or when the incident light is diffuse light, the display image is prevented from being blurred and the display quality is improved.
In such a liquid crystal display device 1, it is preferable that a memory is provided in a pixel. With this configuration, power consumption can be reduced.

FIG. 8 is a view showing another embodiment of the liquid crystal display device as the electro-optical device of the present invention, and is a side sectional view schematically showing a schematic configuration of the liquid crystal display device.
The liquid crystal display device shown in FIG. 8 is different from the liquid crystal display device 1 shown in FIG. 1 in that an organic EL front light 20 is provided on the outer surface side of the polarizing plate 18, that is, outside the scattering film 16. .

The organic EL front light 20 is composed of an organic EL panel, and is affixed on the polarizing plate 18 with the light emitting direction directed toward the liquid crystal cell 2.
That is, the organic EL front light 20 is formed by arranging a large number of point light sources 21 made of organic EL elements in a grid between a pair of transparent substrates as shown in FIG. The organic EL element forming the point light source 21 has an anode (not shown) formed on one of a pair of transparent substrates and a cathode (not shown) formed on the other. It has a known structure formed by laminating organic functional layers such as a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer between the cathodes.

 Note that light emitted from the organic EL element is directed to the liquid crystal cell 2 side at a position corresponding to the point light source 21 on the substrate located on the outer side (the side opposite to the liquid crystal cell 2) of the pair of substrates. In addition, a light shielding layer (not shown) is provided so as not to emit directly. However, since the point light sources (organic EL elements) 21 are arranged in a grid shape as described above, and each of them is formed sufficiently small (in a small area), the light shielding layer corresponding to these point light sources 21 is The observer is hardly visible. Therefore, the display formed by the liquid crystal cell 2 and diffused by the scattering film layer 16 passes through the organic EL front light 20 almost as it is and is visually recognized by the observer.

  Each point light source (organic EL element) 21 has an appropriate light guide structure (not shown), so that emitted light is incident on the polarizing plate 18 in a predetermined direction. . That is, these point light sources 21 are formed with a light guide structure so that light is incident on the scattering film 16 from the minus side of the reference surface 19 shown in FIG.

 Therefore, in the liquid crystal display device shown in FIG. 7, it is possible to perform display by the light of the organic EL front light 20 even when there is no external light source such as sunlight or room light. In addition, since light from the organic EL front light 20 is incident on the scattering film 16 from the minus side, the scattering film layer 16 does not diffuse when the light is incident, and the reflecting plate 14 is not diffused. Thus, the light is diffused only at the time of emission after being reflected by the light, so that the luminance at or near the front surface with respect to the scattering film 16 is greatly improved, and the display quality is excellent. Further, it is possible to prevent the rainbow-like coloring from being visually recognized in the display image.

Next, an electronic apparatus including the liquid crystal display device having the above-described configuration will be described.
FIG. 10 is an external perspective view showing a mobile phone which is an electronic apparatus including the liquid crystal display device of the present invention. The electronic apparatus according to the present embodiment is a mobile phone 300 as shown in FIG. 10, and includes a main body 301 and a display body 302 that can be opened and closed. A display device 303 is arranged inside the display body 302, and various displays relating to telephone communication can be visually recognized on the display screen 304. In addition, operation buttons 305 are arranged on the main body 301.

An antenna 306 is attached to one end of the display body 302 so as to be extendable. In addition, a speaker (not shown) is built in the receiver 307 provided on the upper portion of the display body 302. Furthermore, a microphone (not shown) is built in the transmitter 308 provided at the lower end of the main body 301. Here, the liquid crystal display device shown in FIG. 1 or FIG. 8 is used for the display device 303.
Therefore, in the mobile phone 300, the brightness of the display device 303 at the front or in the vicinity thereof is enhanced, and the rainbow-like coloring is prevented from being visually recognized, and the display quality is remarkably enhanced. , Will be excellent.

  In addition to the cellular phone, the electronic device of the present invention includes, for example, an electronic notebook, personal computer, electronic book, viewfinder type, monitor direct view type video tape recorder, car navigation device, pager, electronic notebook, calculator, word processor. , Workstations, videophones, POS terminals and the like.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the scattering film layer 16 is formed by laminating two scattering films 16A and 16B, but may be formed by laminating three or more.

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device (electro-optical device), 10 ... 1st board | substrate (one board | substrate), 11 ... 2nd board | substrate (the other board | substrate), 12 ... Liquid crystal layer, 14 ... Reflector (reflector), 16 ... Scattering Film layer, 16A, 16B ... scattering film, 19 ... reference plane, 20 ... organic EL front light, 21 ... point light source, 52 ... reference plane, P ... observer, S ... light source, G ... pixel, E1 ... first Range, E2 ... second range, L1 ... first straight line, L2 ... second straight line, Q ... intersection

Claims (6)

An electro-optic material is provided between a pair of substrates arranged opposite to each other, a scattering film layer is provided on one side of the pair of substrates, and reflection is performed on the other side of the pair of substrates. The body is provided,
The scattering film layer transmits incident light, diffuses light reflected from the reflector, and adds one side to the minus side and the other side to the reference plane perpendicular to the surface of the scattering film. The incident light is arranged to be on the minus side, and the diffusion angle range is set to a predetermined value on the plus side from a predetermined angle on the minus side when the normal direction of the scattering film is 0 degree. A scattering film formed with a diffusion characteristic that becomes an angle is formed by laminating a plurality of sheets,
The electro-optical device, wherein the plurality of scattering films have substantially the same diffusion characteristics.   The electro-optical device according to claim 1, wherein a thickness of the one substrate is 0.2 mm or less.  The scattering film has a diffusion characteristic of a first range in which the luminance is substantially constant and the correlation between the diffusion angle and the luminance is approximated by a first straight line in a graph showing the correlation between the diffusion angle and the luminance. The second range in which the luminance changes substantially constant and the correlation between the diffusion angle and the luminance is approximated to the second straight line on the side where the diffusion angle in the first range is close to 0 degrees. The electro-optical device according to claim 1, wherein an intersection of the first straight line and the second straight line is located at a position where the diffusion angle is negative.   The electro-optical device according to claim 1, wherein an organic EL front light is provided outside the scattering film. The scattering film has a property of transmitting light incident from the first direction and diffusing light incident from the second direction, and is disposed so that the first direction is the minus side. ,
The electro-optical device according to claim 4, wherein the organic EL front light is disposed so that light is incident on the scattering film from the first direction.   An electronic apparatus comprising the electro-optical device according to claim 1.

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