JP2004094099A - Light guide, lighting device, electro-optical device, electronic equipment, and manufacturing method of light guide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce thickness in the thickness direction of a light guide in the light guide in a structure for achieving the light emission to both of front and back and various devices using the light guide. <P>SOLUTION: The light guide 2 has a reflection film 4 and a pair of light guide sections 6a, 6b that sandwiches the reflection film 4 and opposes each other. The reflection film 4 is provided between the pair of light guides 6a, 6b by insert formation. The light guide 4 is formed by the insert formation, thus extremely thinning an entire thickness T regardless of the structure where the reflection film 4 is held between the pair of light guide sections 6a, 6b. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a light guide plate for guiding light from a light source to another place and a method for manufacturing the same, a lighting device for applying light to an object, and modulating light using an electro-optical material such as a liquid crystal to achieve a desired function. The present invention relates to an electro-optical device to be obtained and an electronic apparatus configured using the electro-optical device.
[0002]
[Prior art]
Electronic devices such as mobile phones and personal digital assistants include an electro-optical device such as a liquid crystal device, for example, as a display device. A liquid crystal device modulates light supplied to a liquid crystal as an electro-optical material by utilizing the property that the orientation of liquid crystal molecules contained in the liquid crystal changes when the voltage applied to the liquid crystal changes. I do. In order to supply light to the liquid crystal as described above, an illumination device may be provided in the liquid crystal device.
[0003]
Such an illumination device generally converts point-like or linear light from a light source into planar light by using a light guide, and supplies the planar light to a liquid crystal device in many cases. Here, the light guide generally has a light guide 156 and a reflective film 154 fixed to the surface thereof, as shown in FIG. The light emitted from the light source 163 is taken into the light guide 156, is reflected by the reflective film 154 while propagating through the light guide 156, and is emitted to the outside from the surface facing the reflective film 154. Thereby, planar light is obtained (for example, see Patent Document 1).
[0004]
By the way, in a conventional electronic device such as a mobile phone, the display unit is often provided at only one place. However, recently, the display unit is often provided on two different surfaces of the electronic device, for example, the front and back surfaces. Considering the case where the display units provided on the front and back surfaces are each formed by a liquid crystal device, the illumination device attached to the liquid crystal device must supply light in two directions, front and back.
[0005]
[Patent Document 1]
JP-A-5-341284 (page 2, FIG. 1)
[0006]
[Problems to be solved by the invention]
However, in order to supply light in the two directions of the front and back as described above, since the light guide portion of the light guide plate must be provided on both the front and back sides of the reflection film, the thickness of the light guide plate becomes extremely thick, and In addition, there has been a problem that the overall thickness of the illumination device, the overall thickness of the electro-optical device such as a liquid crystal device, and the overall thickness of the electronic device are extremely large.
[0007]
The present invention has been made in view of the above problems, and in a light guide having a structure capable of emitting light on both front and back surfaces and various devices using the same, the thickness of the light guide in the thickness direction is reduced. The purpose is to make it thin.
[0008]
[Means for Solving the Problems]
(1) In order to achieve the above object, a light guide according to the present invention has a reflective film and a pair of light guides facing each other with the reflective film interposed therebetween, and the reflective film is formed by insert molding. It is provided between the pair of light guides.
[0009]
A conventional light guide having a structure in which two light guides are stacked with a reflective film interposed therebetween, for example, bonded with an adhesive, has a thickness of at least two light guides. On the other hand, according to the light guide according to the present invention having the above-described configuration, since the reflection film is disposed in the light guide by insert molding, the entire thickness of the light guide is the same as that of the conventional light guide. Is almost the same as the thickness of one of the light guides. That is, according to the present invention, the thickness of the light guide having the function of emitting light to both the front and back surfaces can be extremely reduced. Further, since the thickness of the reflection film and the light guide can be reduced, cost reduction can be achieved.
[0010]
(2) In the light guide having the above configuration, the insert molding is performed by injecting the material of the light guide portion into the material ejection space with the reflective film placed in the material ejection space of the molding apparatus. be able to. Thereby, the reflection film can be accurately embedded in the light guide.
[0011]
(3) Next, a lighting device according to the present invention includes the light guide having the above-described configuration, and a light source that inputs light to one or both of the pair of light guides. According to the light guide having the above-described configuration, the thickness of the light guide can be extremely reduced. Therefore, the thickness of a lighting device incorporating the light guide can be extremely reduced. In addition, since the cost can be reduced for the light guide having the above-described configuration, the cost can be also reduced for the lighting device incorporating the light guide.
[0012]
(4) In the lighting device having the above configuration, the thickness of the light guide can be set to be substantially the same as the light emitting area of the light source. This can prevent light emitted from the light source from leaking outside without entering the light guide.
[0013]
(5) Next, an electro-optical device according to the present invention includes the illumination device having the above-described configuration, and an electro-optical panel to which light is supplied by the illumination device. With respect to the lighting device having the above-described configuration, the thickness of the light guide included therein can be made extremely thin, so that the thickness of the lighting device can be made very thin. Therefore, the thickness of the electro-optical device incorporating the illumination device can be extremely reduced. Further, since the cost can be reduced for the illumination device having the above-described configuration, the cost can also be reduced for an electro-optical device incorporating the illumination device.
[0014]
In general, an electro-optical panel is a panel structure that incorporates an electro-optical material such as a liquid crystal, and can be supplied to the market as one unit. If a wiring board such as an FPC (Flexible Printed Circuit) is mounted on the electro-optical panel, a signal or a power supply voltage can be supplied from an external circuit to the electro-optical panel through the wiring board. If a lighting device is attached to the electro-optical panel, light can be supplied to the electro-optical panel.
[0015]
Generally, an electro-optical panel is often recognized as an electro-optical element that does not include ancillary devices such as a wiring board and a lighting device. However, if an object having a wiring board and a lighting device mounted on a panel structure is supplied to the market as one unit, the entire object including the wiring substrate and the lighting device is recognized as one electro-optical panel. It doesn't hurt at all.
[0016]
Further, if the electro-optical panel includes a plurality of panel structures, and the panel structures are supplied to the market in a state where the panel structures are connected by a wiring board, a structure including the plurality of panel structures is provided. Can be recognized as one electro-optical panel.
[0017]
Next, the electro-optical device refers to any device that includes an electro-optical material and can be one of a plurality of constituent elements of an electronic device such as a mobile phone. Specifically, the electro-optical panel is also one electro-optical device, the one in which the wiring substrate is connected to the electro-optical panel is one electro-optical device, and the one in which the lighting device is provided in the electro-optical panel is one electro-optical device. Optical device.
[0018]
(6) In the electro-optical device having the above configuration, the electro-optical panel can be configured by a panel structure including a liquid crystal layer. The electro-optical device thus configured is a liquid crystal device. In a liquid crystal device, a pair of electrodes are provided so as to sandwich a liquid crystal layer, and the voltage applied between these electrodes is controlled to control the alignment of liquid crystal molecules in the liquid crystal for each pixel. Thereby, the light passing through the liquid crystal layer is modulated for each pixel according to the alignment state of the liquid crystal molecules.
[0019]
(7) Next, an electronic apparatus according to the present invention includes the electro-optical device having the above-described configuration, and control means for controlling an operation of the electro-optical device. With respect to the electro-optical device having the above-described configuration, the thickness of the light guide included therein can be extremely reduced, so that the thickness of the electro-optical device can be extremely reduced. For this reason, the thickness of the electronic apparatus incorporating the electro-optical device can be extremely reduced. In addition, since the cost can be reduced with respect to the electro-optical device having the above-described configuration, the cost can be reduced with respect to an electronic device incorporating the same.
[0020]
(8) Next, in the method for manufacturing a light guide according to the present invention, in the method for manufacturing a light guide having a reflective film and a pair of light guides opposed to each other with the reflective film interposed therebetween, It is provided between the pair of light guides by insert molding.
[0021]
With respect to a conventional method of manufacturing a light guide in which two light guides are overlapped with a reflective film interposed therebetween, for example, with an adhesive, the completed light guide has a thickness of at least two light guides. Was. On the other hand, according to the method for manufacturing a light guide according to the present invention having the above configuration, since the reflection film is disposed in the light guide by insert molding, the overall thickness of the completed light guide is: It is almost the same as the thickness of one light guide in a conventional light guide. That is, according to the present invention, the thickness of the light guide can be extremely reduced. Further, since the thickness of the reflection film and the light guide can be reduced, cost reduction can be achieved.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment of light guide and lighting device, and embodiment of manufacturing method of light guide)
Hereinafter, an embodiment of a light guide, an embodiment of a lighting device, and an embodiment of a method of manufacturing a light guide according to the present invention will be described with reference to FIG. This embodiment is an example of the present invention, and the present invention is not limited to this embodiment.
[0023]
In FIG. 1, a lighting device 1 according to the present invention includes a light guide 2 and a light source 3. Generally, a plurality of light sources 3 are provided, and three light sources 3 are provided in the present embodiment. Further, the light guide 2 includes a reflective film 4 and a pair of light guide portions 6a and 6b facing each other with the reflective film 4 interposed therebetween.
[0024]
The reflection film 4 is disposed at a substantially central position in the thickness T direction of the light guide 4. That is, the thicknesses of the light guide 6a and the light guide 6b are set to be substantially equal. Further, the reflection film 4 is disposed substantially parallel to the respective surfaces of the light guide portions 6a and 6b. As the light source 3, a light source having an arbitrary structure can be used. For example, a white light light source using a YAG phosphor, a so-called three-wavelength white light light source, or the like can be used.
[0025]
The YAG phosphor is formed, for example, by using a blue LED 7 as a light emitting element and providing a resin 8 containing the YAG phosphor on the light emitting surface of the blue LED 7 as shown in FIG. In this way, when the blue light generated from the blue LED 7 passes through the resin 8, a part of the blue light impinges on the YAG phosphor and is converted into yellow light, that is, mixed light of green light and red light. White light is obtained by mixing with blue light emitted outside without hitting the phosphor.
[0026]
As shown in FIG. 5B, the so-called three-wavelength light source is, for example, a light emitting element that emits light having a wavelength of about 30 to 410 nm, that is, ultraviolet light, for example, an LED 9, and a fluorescent light provided around the LED 9. Substance 11. The fluorescent substance 11 emits R (red) light in response to ultraviolet light, a G phosphor that emits G (green) light in response to ultraviolet light, and emits B (blue) light in response to ultraviolet light. And a B phosphor. When the LED 9 emits light to generate ultraviolet light, the light strikes the R, G, and B color phosphors and is converted into light of each color, and the lights are mixed and recognized as white light to the outside.
[0027]
In the present embodiment, the light guide 2 is formed by so-called insert molding. This insert molding is injection molding known per se. Specifically, in a state where an insert substance is previously put in an injection space which is a space where resin is to be injected, a resin melted at a high temperature in the injection space. And then further cooling to produce a resin product having an outer shape corresponding to the shape of the injection space.
[0028]
In this embodiment, the light guide portions 6a and 6b are formed on both the front and back surfaces of the reflection film 4 by injecting a resin into the emission space in a state where the reflection film 4 is disposed in the emission space as an insert material. In this case, the reflection film 4 can be formed by depositing a light-reflective substance, for example, aluminum on both front and back surfaces of iron or stainless steel. The thickness of the reflection film 4 can be formed to about 0.1 mm.
[0029]
Further, the light guide portions 6a and 6b can be formed of, for example, acrylic or polycarbonate. The overall thickness T of the light guide 2 can be set to about 0.5 mm according to the characteristics of the injection molding process. In the present embodiment, the thickness T of the light guide 2 is set to about 0.75 mm in consideration of a positional shift when the light guide is incorporated in an electro-optical device such as a liquid crystal device.
[0030]
In the conventional light guide shown in FIG. 15, since one light guide has a thickness of, for example, about 0.75 mm, two light guides are stacked to emit light to both front and back surfaces. When used, the overall thickness was 0.75 mm × 2 = 1.5 mm or more. On the other hand, according to the present embodiment using insert molding, the entire thickness T of the light guide 2 including the reflection film 4 is set to the thickness of one injection molded product, for example, 0.5 mm to 0.75 mm. Can be suppressed to the extent.
[0031]
Thus, the light guide 2 having a structure in which the two light guide portions 6a and 6b are overlapped can be formed very thin. Also, compared to the conventional structure in which two light guides are superimposed, the number of parts is reduced, and the cost can be reduced.
[0032]
The light source 3 has a unique light emitting area A as shown in FIGS. 5A and 5B, and the light emitting area A is substantially equal to the thickness T of the light guide 2. Is set to This can be set by adjusting the size of the light emitting area A of the light source 3, adjusting the thickness T of the light guide 2, or adjusting the distance between the light source 3 and the light guide 2. This can prevent the light emitted from the light source 3 from leaking outside without entering the light guide 2.
[0033]
Since the lighting device 1 of the present embodiment is configured as described above, as shown in FIG. 2, the light emitted from the light source 3 emits light at the side ends of the light guides 6 a and 6 b of the light guide 2, that is, The light is introduced into the light guides 6a and 6b from the light receiving surface, and is reflected on the front and back surfaces of the reflection film 4 while propagating through the light guides 6a and 6b. The light is emitted to the outside as light B. Thereby, the point light from the light source 3 is converted into the plane light.
[0034]
In addition, an uneven pattern for guiding light to the outside can be formed on the light emitting surfaces of the light guide portions 6a and 6b and the opposite surface as necessary. Reference numeral 12 denotes an optical sheet such as a diffusion sheet, a prism sheet (light collecting sheet), or the like. Further, the light source 3 is not limited to the point light source used in the present embodiment, but may be a linear light source such as a cold cathode tube.
[0035]
(Other Embodiments of Light Guide and Lighting Device)
FIG. 3 shows another embodiment of a light guide and a lighting device. The embodiment shown here differs from the embodiment shown in FIG. 1 in that the arrangement of the reflection film 4 in the light guide 22 is modified and the arrangement of the light source 3 is modified. is there.
[0036]
Specifically, the reflection film 4 is provided in a state of being inclined over the diagonal portion of the light guide 22, and the light guide portions 16 a and 16 b are formed in a substantially wedge shape correspondingly. Is formed in a flat plate shape as a whole. 3 has a light receiving surface 13 on the near side in FIG. 3, and the lower light guide 16b on the lower side in FIG. 3 has a light receiving surface 13 on the far side in FIG. Therefore, the light sources 3 are disposed on two opposing side end surfaces of the light guide 22 corresponding to the light receiving surfaces 13. The light guides 16a and 16b, the reflection film 4, and the light source 3 can be formed of the same material as that of the light guide 2 in FIG.
[0037]
The light guide 22 is formed by insert molding in the same manner as the light guide 2 shown in FIG. Therefore, the entire thickness T of the light guide 22 can be formed to be substantially the same as the thickness of one conventional light guide shown in FIG. 15, for example. Thus, the thickness T of the light guide 22 having the structure in which the two light guides 16a and 16b are overlapped can be formed very thin. Further, cost reduction can be achieved by reducing the number of parts.
[0038]
Since the lighting device 21 of the present embodiment is configured as described above, as shown in FIG. 4, light emitted from the light source 3 is applied to the side edges of the light guides 16 a and 16 b of the light guide 22, that is, The light is introduced into the light guides 16a and 16b from the light receiving surfaces 13 and reflected on the front and back surfaces of the reflection film 4 while propagating through the light guides 16a and 16b. The light exits from the surface as plane light B to the outside. Thereby, the point light from the light source 3 is converted into the plane light.
[0039]
In addition, an uneven pattern for guiding light to the outside can be formed on the light emitting surfaces of the light guide portions 16a and 16b and the opposite surface as necessary. Reference numeral 12 denotes an optical sheet such as a diffusion sheet, a prism sheet (light collecting sheet), or the like. Further, the light source 3 is not limited to the point light source used in the present embodiment, but may be a linear light source such as a cold cathode tube.
[0040]
(Embodiment of electro-optical device)
Hereinafter, an electro-optical device according to the present invention will be described by taking a simple matrix type transflective liquid crystal device as an example. This embodiment is an example of the present invention, and the present invention is not limited to this embodiment.
[0041]
In FIG. 6, a liquid crystal device 31 includes a first liquid crystal panel 32 acting as a main display, a second liquid crystal panel 33 acting as a sub-display, and a lighting device 34 commonly used as a backlight for those liquid crystal panels. Having. The lighting device 34 is supported by a casing 36, and the first liquid crystal panel 32 and the second liquid crystal panel 33 are also supported by the casing 36. The lighting device 34 is configured by the lighting device 1 shown in FIGS. 1 and 2.
[0042]
The first liquid crystal panel 32 has a first substrate 37a, which is a substrate on the observation side, and a second substrate 37b, which is a substrate facing the first substrate 37a. A polarizing plate 38a is fixed to the outer surface of the first substrate 37a by, for example, bonding, and a polarizing plate 38b is fixed to the outer surface of the second substrate 37b by, for example, bonding. Each of the first substrate 37a and the second substrate 37b is formed in a square shape or a rectangular shape when viewed from the arrow C direction. In addition, the first substrate 37a has an overhang 39 protruding outside the second substrate 37b on one side thereof.
[0043]
FIG. 7 shows an enlarged cross-sectional structure of the peripheral portion of the first liquid crystal panel 32 indicated by the arrow D. In FIG. 7, a sealing material 29 is formed on the surface of the first substrate 37a or the second substrate 37b along the edge of the substrate by printing or the like. Then, the first substrate 37a and the second substrate 37b are bonded to each other with a gap maintained by the spacer 28, that is, a so-called cell gap, by the sealing material 29. An opening (not shown) is formed at an appropriate position of the sealing material 29, and a liquid crystal, for example, a STN (Super Twisted Nematic) liquid crystal 27 is injected into the cell gap through the opening. The opening is sealed with a resin after the completion of the liquid crystal injection. The first substrate 37a is formed on a first substrate 41a formed of transparent glass, transparent plastic, or the like, a color filter 49 formed on an inner surface of the first substrate 41a, and formed on the color filter 49. A first electrode 44a and an alignment film 46a formed on the first electrode 44a.
[0044]
The first electrode 44a is formed in a predetermined pattern by a photolithography process and an etching process using a transparent metal oxide such as ITO (Indium Tin Oxide). In this embodiment, in order to configure a simple matrix type liquid crystal panel, a plurality of first electrodes 44a extending linearly in the left-right direction of FIG. 7 are arranged in parallel in the direction perpendicular to the paper of FIG. To form a stripe. Note that a portion extending from the first electrode 44a and existing outside the sealing material 29 is a wiring 48.
[0045]
The alignment film 46a is formed, for example, by applying a polyimide solution and then firing. The alignment film 46a is subjected to an alignment process, for example, a rubbing process, and the rubbing process determines the alignment of the liquid crystal molecules near the alignment film 46a.
[0046]
The second substrate 37b facing the first substrate 37a includes a second substrate 41b formed of transparent glass, transparent plastic, or the like, a transflective film 42 formed on the second substrate 41b, It has an insulating film 43 formed on the transmission / reflection film 42, a second electrode 44b formed on the insulating film 43, and an alignment film 46b formed thereon.
[0047]
The transflective film 42 is formed, for example, by forming a film of aluminum or another light-reflective metal by photolithography. Further, in order to achieve the effect of transmitting light, an opening 47 is formed at an appropriate position of the reflection film by etching or the like. Generally, in a liquid crystal panel, an image such as a character, a number, a graphic, or the like is often displayed by selectively lighting a plurality of display dots arranged in a dot matrix. It is formed corresponding to the dot.
[0048]
Like the first electrode 44a, the second electrode 44b is formed in a stripe shape when viewed from the direction of arrow C, but its extending direction is set in a direction orthogonal to the first electrode 44a, that is, in a direction perpendicular to the plane of FIG. Is done. The alignment film 46b is subjected to an alignment process, for example, a rubbing process, whereby the alignment of the liquid crystal molecules near the alignment film 46b is determined.
[0049]
FIG. 8 is an enlarged cross-sectional view of the central portion of the liquid crystal panel indicated by arrow E in FIG. In this figure, a square area or a rectangular area formed by crossing a first electrode 44a extending in the left-right direction of the figure and a second electrode 44b extending in a direction perpendicular to the paper of the figure when viewed in the direction of the arrow C is shown. A display dot 51 which is a minimum unit is formed. The plurality of display dots 51 are arranged in a matrix when viewed from the direction of arrow C, and these display dots 51 form a display area.
[0050]
As shown in FIG. 8, the color filter 49 formed in the first substrate 37a of FIG. 7 includes three primary color picture elements 52 of R (red), G (green), and B (blue) as display dots. It is formed by arranging it corresponding to 51. The space between these color picture elements 52 is filled with a black mask 53. In the present embodiment, since color display is performed by three colors of R, G, and B, one pixel is constituted by three display dots corresponding to these three colors. On the other hand, when displaying black and white without using a color filter, one display dot 51 forms one pixel.
[0051]
The color filter 49 can be formed by any method. For example, in the case of using a so-called pigment dispersion method, a pigment corresponding to one of R, G, and B is dispersed in a photosensitive photoresist. Is applied to the surface of the base material by spin coating or another film forming method, the pattern is exposed after drying, and the pattern is further developed, which is repeated for each color. Further, it can also be formed by a method of discharging and fixing each color picture element to a predetermined position based on an ink jet method. Further, the black mask 53 can be formed of a light-absorbing metal such as chromium or a black resin material in which carbon black is dispersed, or by superposing R, G, and B color picture elements. It can also be formed by a method of forming a black area.
[0052]
Returning to FIG. 6, the first liquid crystal panel 32 is configured as described above. On the other hand, the second liquid crystal panel 33 disposed on the surface opposite to the first liquid crystal panel 32 can have the same configuration as the first liquid crystal panel 32. However, the display surface of the first liquid crystal panel 32 is on the upper side of FIG. 6, while the display surface of the second liquid crystal panel 33 is on the lower side of FIG. In the first liquid crystal panel 32 and the second liquid crystal panel 33, the voltage applied between the first electrode 44a and the second electrode 44b is controlled for each display dot 51 in FIG. The orientation of the liquid crystal molecules is controlled for each display dot 51. Thus, the light passing through the layer of the liquid crystal 27 is modulated for each display dot 51, and an image is displayed to the outside depending on whether the modulated light passes or does not pass through the polarizing plate 38a in FIG.
[0053]
Since the liquid crystal panel of the present embodiment is a transflective liquid crystal panel, there are two types of light to be supplied to the layer of the liquid crystal 27, a reflection type and a transmission type. The reflection method is a method of performing display using external light in an environment where the present liquid crystal device is placed, for example, when the outdoors or the room is bright. On the other hand, the transmission method is a method of performing display using the illumination device 34 of FIG. 6 as a backlight when the outdoors or indoors are dark.
[0054]
In the case of the reflection type, the external light passes through the layer of the liquid crystal 27 from the first substrate 37a, which is the observation side substrate, and is reflected by the semi-transmissive reflection film 42 of the second substrate 37b, as shown by the arrow R in FIG. Then, it is supplied to the layer of the liquid crystal 27 again. On the other hand, in the case of the transmission system, as shown by the arrow S, the plane light emitted from the illumination device 34 (see FIG. 6) is supplied to the layer of the liquid crystal 27 through the opening 47 of the semi-transmissive reflection film 42. . As described above, the light supplied to the layer of the liquid crystal 27 is modulated according to the alignment state of the liquid crystal molecules.
[0055]
In the liquid crystal device 31 of the present embodiment, the first liquid crystal panel 32 serves as a main display, and the second liquid crystal panel 33 serves as a sub-display, and display can be performed on one or both of these displays. For example, if a mobile phone having a foldable structure is considered as an electronic device, the main display as the mobile phone can be performed using the first liquid crystal panel 32 when the mobile phone is used in an open state. When not used in the closed state, auxiliary display can be performed using the second liquid crystal panel 33.
[0056]
According to the liquid crystal device 31 shown in FIG. 6 according to this embodiment, the lighting device 34 used for the liquid crystal device 31 is configured by the lighting device 1 shown in FIG. Further, since the light guide 2 included in the lighting device 1 is formed by insert molding, the thickness can be extremely reduced. Therefore, the liquid crystal device 31 configured using the lighting device 34 can be formed very thin. In addition, the light guide 2 in the lighting device 1 of FIG. 1 can be formed of a material for approximately one conventional light guide, despite the fact that both front and back surfaces are light-emitting surfaces. Accordingly, the cost of the liquid crystal device 31 using the same can be suppressed.
[0057]
(Other Embodiments of Electro-Optical Device)
FIG. 9 shows another embodiment of the electro-optical device according to the present invention. This embodiment is an example of the present invention, and the present invention is not limited to this embodiment. The liquid crystal device 61 according to this embodiment is a modification of the liquid crystal device 31 shown in FIG. 6, and specifically, the lighting device 34 shown in FIG. 6 is replaced with the lighting device 1 shown in FIGS. Instead of using the illumination device 34, the illumination device 34 is configured by the illumination device 21 shown in FIGS.
[0058]
According to the liquid crystal device 61 according to the present embodiment, the lighting device 34 used for the same is configured by the lighting device 21 shown in FIG. Further, since the light guide 22 included in the lighting device 21 is formed by insert molding, the thickness can be extremely reduced. Therefore, the liquid crystal device 61 configured using the lighting device 34 can be formed very thin. In addition, the light guide 22 in the lighting device 21 of FIG. 3 can be formed of a material of substantially one conventional light guide, despite the fact that both front and back surfaces are light emitting surfaces, so that the cost is low. Therefore, the cost of the liquid crystal device 61 using the same can be reduced.
[0059]
(Modification)
The electro-optical device to which the present invention can be applied is not limited to a simple matrix type liquid crystal device, and an active matrix type liquid crystal having a structure using a two-terminal switching element such as a TFD (Thin Film Diode) as an active element. An active matrix type liquid crystal device having a structure using a device or a three-terminal switching element such as a TFT (Thin Film Transistor) as an active element is also conceivable.
[0060]
Further, the present invention is not limited to the liquid crystal device, and can be applied to an electro-optical device having any other structure that requires a lighting device.
[0061]
(Embodiment of electronic device)
Hereinafter, an electronic device according to the invention will be described with reference to embodiments. This embodiment is an example of the present invention, and the present invention is not limited to this embodiment.
[0062]
FIG. 10 shows an embodiment of an electronic device according to the present invention. The electronic device shown here includes a display information output source 101, a display information processing circuit 102, a power supply circuit 103, a timing generator 104, and a liquid crystal device 105. The liquid crystal device 105 has a liquid crystal panel 107 and a driving circuit 106.
[0063]
The display information output source 101 includes a memory such as a random access memory (RAM), a storage unit such as various disks, a tuning circuit that tunes and outputs a digital image signal, and the like, and various clock signals generated by the timing generator 104. , The display information such as an image signal in a predetermined format is supplied to the display information processing circuit 102.
[0064]
Next, the display information processing circuit 102 includes a number of well-known circuits such as an amplification / inversion circuit, a rotation circuit, a gamma correction circuit, and a clamp circuit, and executes processing of input display information to convert an image signal. It is supplied to the drive circuit 106 together with the clock signal CLK. Here, the driving circuit 106 is a general term for an inspection circuit and the like together with a scanning line driving circuit (not shown) and a data line driving circuit (not shown). The power supply circuit 103 supplies a predetermined power supply voltage to each of the above components.
[0065]
The liquid crystal device 105 can be configured, for example, similarly to the liquid crystal device 31 shown in FIG. 6 or the liquid crystal device 61 shown in FIG. Since the liquid crystal device 31 and the liquid crystal device 61 can be formed very thin, the present electronic device using them can also be formed very thin. Further, since the liquid crystal device 31 and the liquid crystal device 61 can be formed at low cost, the present electronic device using them can also be formed at low cost.
[0066]
FIG. 11 shows a mobile personal computer as another embodiment of the electronic apparatus according to the invention. The personal computer 110 shown here comprises a main body 114 having a keyboard 112 and a cover 118 having a liquid crystal display unit 116. If the liquid crystal display unit 116 is constituted by the liquid crystal device 31 shown in FIG. 6 or the liquid crystal device 61 shown in FIG. 9, the back surface of the cover part 118 (the surface depicted in FIG. 11) is used as a main display. The front surface of the cover 118, which is the back surface, can be used as a sub-display.
[0067]
FIG. 12 shows a mobile phone as still another embodiment of the electronic apparatus according to the present invention. The mobile phone 120 shown here has a first body 121a and a second body 121b that can be folded around a hinge 122. The first body 121a is provided with a liquid crystal display device 123, an earpiece 124, and an antenna 126. The second body 121b is provided with a plurality of operation buttons 127 and a mouthpiece 128.
[0068]
When the liquid crystal display device 123 is configured by the liquid crystal device 31 shown in FIG. 6 or the liquid crystal device 61 shown in FIG. 9, the back surface (the surface depicted in FIG. 12) of the first body 121a is used as a main display. The back surface of the first body 121a can be used as a sub-display.
[0069]
FIG. 13 shows a wristwatch-type electronic device as still another embodiment of the electronic device according to the present invention. The wristwatch-type electronic device 140 shown here has a liquid crystal display device 142 as a display unit supported by a watch main body 141. If the liquid crystal display device 142 is constituted by the liquid crystal device 31 shown in FIG. 6 or the liquid crystal device 61 shown in FIG. 9, the surface of the timepiece body 141 (the surface depicted in FIG. 13) is used as a main display. The back surface can be used as a sub-display.
[0070]
The liquid crystal display device 142 is controlled by a control circuit 143 provided inside the timepiece body 141, and displays time, date, and the like as information on a main display. Further, other necessary information can be displayed on the sub-display.
[0071]
FIG. 14 shows a PDA (Personal Digital Assistant), which is still another embodiment of the electronic apparatus according to the present invention. The PDA 150 shown here has an input device 151 of a contact type, so-called touch panel type, on its front panel. The input device 151 is transparent, and a liquid crystal display device 152 as a display unit is disposed below the input device 151. By touching the pen-type input tool 153 attached to the input surface of the input device 151, the user can select buttons displayed on the liquid crystal display device 152, other displays, draw characters, figures, and the like. And enter the required information. A predetermined operation is performed on the input information by the computer in the PDA 150, and the result of the operation is displayed on the liquid crystal display device 152.
[0072]
When the liquid crystal device 31 shown in FIG. 6 or the liquid crystal device 61 shown in FIG. 9 is used as the liquid crystal display device 152, the front surface (the surface depicted in FIG. 14) of the PDA 150 is used as a main display, and the back surface is used as a sub display. It can be used as a display.
[0073]
(Modification)
In addition to the personal computer, the mobile phone, the wristwatch type electronic device, and the PDA described above, the electronic device may be a liquid crystal television, a viewfinder type or a monitor direct-view type video tape recorder, a car navigation system, or the like. Examples include a device, a pager, an electronic organizer, a calculator, a word processor, a workstation, a videophone, a POS terminal, and the like.
[0074]
(Other embodiments)
As described above, the present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and can be variously modified within the scope of the invention described in the claims.
[0075]
【The invention's effect】
As described above, according to the present invention, the light guide formed by sandwiching the reflection film between the pair of light guides has a laminated structure formed by insert molding. The thickness can be almost the same as the thickness of a conventional light guide in which only one surface is a light emitting surface. That is, according to the present invention, the thickness of the light guide whose front and back surfaces are light emission surfaces can be extremely reduced. Further, since the thickness of the reflection film and the light guide can be reduced, cost reduction can be achieved.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a light guide and an embodiment of a lighting device according to the present invention.
FIG. 2 is a side sectional view of the lighting device of FIG. 2;
FIG. 3 is a perspective view showing another embodiment of the light guide according to the present invention and another embodiment of the lighting device.
FIG. 4 is a side sectional view of the lighting device of FIG. 3;
FIG. 5 is a cross-sectional view showing one embodiment of a light source.
FIG. 6 is a sectional view showing an embodiment of the electro-optical device according to the present invention.
7 is an enlarged cross-sectional view illustrating a cross-sectional structure of a peripheral portion of the liquid crystal panel indicated by an arrow D in FIG.
8 is an enlarged cross-sectional view showing a cross-sectional structure of the liquid crystal panel indicated by an arrow E in FIG.
FIG. 9 is a sectional view showing another embodiment of the electro-optical device according to the present invention.
FIG. 10 is a block diagram illustrating an embodiment of an electronic apparatus according to the invention.
FIG. 11 is a perspective view showing a personal computer as another embodiment of the electronic apparatus according to the invention.
FIG. 12 is a perspective view showing a mobile phone as still another embodiment of the electronic apparatus according to the invention.
FIG. 13 is a perspective view showing a wristwatch-type electronic device as still another embodiment of the electronic device according to the present invention.
FIG. 14 is a perspective view showing a PDA as still another embodiment of the electronic apparatus according to the invention.
FIG. 15 is a perspective view showing an example of a conventional light guide.
[Explanation of symbols]
1: Lighting device
2: Light guide
3: Light source
4: Reflective film
6a, 6b: light guide section
12: Optical sheet
16a, 16b: light guide section
21: Liquid crystal device (electro-optical device)
22: Light guide
27: Liquid crystal
31: Liquid crystal device
32: First liquid crystal panel
33: second liquid crystal panel
34: Lighting device
61: Liquid crystal device (electro-optical device)
110: Computer (electronic device)
120: Mobile phone (electronic device)
140: Wristwatch type electronic device (electronic device)
150: PDA (electronic equipment)

Claims (8)

A light guide, comprising: a reflective film; and a pair of light guides facing each other with the reflective film interposed therebetween, wherein the reflective film is provided between the pair of light guides by insert molding. 2. The method according to claim 1, wherein the insert molding is performed by injecting the material of the light guide into the material injection space with the reflective film placed in the material injection space of a molding apparatus. Light guide. An illumination device comprising: the light guide according to claim 1 or 2; and a light source that inputs light to one or both of the pair of light guides. 4. The lighting device according to claim 3, wherein the light guide has substantially the same thickness as a light emitting area of the light source. An electro-optical device comprising: the lighting device according to claim 3; and an electro-optical panel to which light is supplied by the lighting device. The electro-optical device according to claim 5, wherein the electro-optical panel is a panel structure including an electro-optical layer. 7. An electronic apparatus comprising: the electro-optical device according to claim 5; and control means for controlling an operation of the electro-optical device. In a method for manufacturing a light guide having a reflective film and a pair of light guides opposed to each other with the reflective film interposed therebetween, the reflective film is provided between the pair of light guides by insert molding. Of producing a light guide.

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