JP2007025630A - Liquid crystal device, and electronic appliance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal device for a double-sided display with which display unevenness is scarcely visually recognized by reducing a footprint of a reflection polarizing plate and, while modulating an abrupt change of a reflectance, and an electronic appliance. <P>SOLUTION: In the liquid crystal device for the double-sided display including first and second liquid crystal panels disposed so as to at least partially overlap with each other in a plan view via an illuminator, a reflection polarizing plate is equipped between the second liquid crystal panel and the illuminator, and in a region which is in a reflection polarizing plate non-existing region of the illuminator on the second liquid crystal panel side and is at least adjacent to the reflection polarizing plate, a reflectance adjusting member for making light reflectance in the region come close to that in a reflection polarizing plate existing region, different from the reflection polarizing plate, is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal device and electronic device for double-sided display, and more particularly to a liquid crystal device and electronic device for front and back double-sided display in which two liquid crystal panels are arranged back to back with an illumination device interposed therebetween.

  Conventionally, in a liquid crystal device, a pair of substrates each having an electrode formed thereon are arranged opposite to each other, and a voltage applied to a plurality of pixels that are intersecting regions of the respective electrodes is selectively turned on and off, whereby The light passing through the liquid crystal material is modulated to display an image such as an image or a character. In recent years, as a liquid crystal device used in an electronic device such as a mobile phone or a PDA (Personal Digital Assistant), there is a liquid crystal device for front and back display in which two liquid crystal panels are arranged back to back with an illumination device interposed therebetween.

In such a liquid crystal device for double-sided display, there has been proposed a display device capable of effectively using light and capable of performing bright display without increasing power consumption. For example, as shown in FIG. 14, two liquid crystal panels 510 and 520, a backlight 540 that is formed between the liquid crystal panels 510 and 520 and can irradiate the liquid crystal panels 510 and 520, and the backlight A display device 500 including two reflective polarizing plates 531 and 532 formed between a light 540 and liquid crystal panels 510 and 520 is disclosed (see Patent Document 1).
According to such a display device, each reflective polarizing plate transmits light having a predetermined polarization direction, while reflecting light having another polarization direction to display light irradiated from the illumination device. It can be used without waste.
JP-A-2004-199027 (Claims, FIGS. 5 and 6)

However, the reflective polarizing plate used in the display device described in Patent Document 1 is generally high in cost, and like the disclosed display device, the reflective polarizing plate is disposed on both sides of the lighting device, so that the display device itself In some cases, the production cost would be high.
In addition, such a reflective polarizing plate is originally required to be disposed only in a region where the first liquid crystal panel and the second liquid crystal panel that need to transmit light are present on each surface of the lighting device. However, when the reflective polarizing plate is partially arranged, there is a problem that the light reflectance is partially different. In such a case, if the size of the display surface of the first liquid crystal panel is different from that of the second liquid crystal panel, display unevenness due to the difference in light reflectance is visually recognized on the display surface of the other liquid crystal panel. The case was seen.

Accordingly, the inventors of the present invention diligently worked on a liquid crystal device for double-sided display having two liquid crystal panels arranged so as to overlap in a plane with an illumination device interposed therebetween. The present invention has been completed by finding that such a problem can be solved by disposing only in the existing region of the reflective polarizing plate and providing a predetermined reflectance adjusting member in the non-existing region of the reflective polarizing plate.
That is, the present invention provides a liquid crystal device for double-sided display in which display unevenness due to different light reflectance is not visually recognized even when a reflective polarizing plate is used in a minimum range. Objective. Another object of the present invention is to provide an electronic apparatus including such a liquid crystal device.

According to the present invention, the first liquid crystal panel that holds the liquid crystal material, and the second liquid crystal panel that holds the liquid crystal material and that is disposed so as to at least partially overlap the first liquid crystal panel A liquid crystal device for double-sided display including a lighting device disposed between the first liquid crystal panel and the second liquid crystal panel,
Between the second liquid crystal panel and the illuminating device, only light having a predetermined polarization direction out of light emitted from the illuminating device is incident on the second liquid crystal panel side, and light having another polarization direction is incident on the second liquid crystal panel. A reflective polarizing plate for reflecting toward the first liquid crystal panel,
On the second liquid crystal panel side of the illuminating device, in the non-existing region of the reflective polarizing plate, at least in the region adjacent to the reflective polarizing plate, the reflectance of the light in the region is expressed, and the light in the existing region of the reflective polarizing plate A liquid crystal device including a reflectance adjusting member that is different from the reflective polarizing plate for bringing the reflectance closer to the reflectance is provided, and the above-described problems can be solved.
That is, an increase in production cost can be suppressed by arranging a reflective polarizing plate that reflects light in another polarization direction while allowing light in a specific polarization direction to pass therethrough. Even in such a case, by providing a predetermined reflectance adjusting member in a predetermined region adjacent to the region where the reflective polarizing plate is present, light is reflected on the display surface of the first liquid crystal panel. It is possible to effectively prevent display unevenness due to different rates from being visually recognized. Therefore, it is possible to provide a liquid crystal device for double-sided display that has excellent display quality while suppressing an increase in production cost.

In configuring the liquid crystal device of the present invention, it is preferable that the first liquid crystal panel is disposed so as to overlap in a plane across the existing region and the non-existing region of the reflective polarizing plate.
With this configuration, even when the first liquid crystal panel is disposed so as to face the existing region and the non-existing region of the reflective polarizing plate, the back side of the display surface of the first liquid crystal panel In this case, the light reflectance does not change rapidly. Therefore, it is possible to effectively prevent display unevenness due to the difference in reflectance.

Further, in configuring the liquid crystal device of the present invention, it is preferable to arrange the reflectance adjusting member over the entire non-existing region of the reflective polarizing plate.
With this configuration, the difference in the light reflectance between the existing region and the non-existing region of the reflective polarizing plate can be reduced, and the light reflectance in the non-existing region can be made uniform. It is possible to effectively prevent the display unevenness in the liquid crystal panel from being visually recognized.

Further, when the reflectance adjusting member is arranged in the entire non-existing region of the reflective polarizing plate in configuring the liquid crystal device of the present invention, the reflectance of light in the region is determined by reflecting the light in the existing region of the reflective polarizing plate. It is preferable to match the rate.
With such a configuration, the reflectance of light reflected toward the first liquid crystal panel can be made uniform, so that display unevenness in the first liquid crystal panel can be more effectively prevented from being visually recognized. .

Further, in the configuration of the liquid crystal device of the present invention, when the reflectance adjusting member is disposed only in the region adjacent to the reflective polarizing plate, the reflectance of light in the region where the reflectance adjusting member is disposed is reflected polarized light. It is preferable to set an intermediate value between the light reflectance in the region where the plate is present and the light reflectance in the region where the reflectance adjusting member is not disposed in the non-existing region.
With this configuration, the reflectance of the light can be varied step by step while reducing the arrangement area of the reflectance adjusting member, thereby preventing display unevenness in the first liquid crystal panel from being visually recognized. And increase in production cost can be suppressed.

In configuring the liquid crystal device of the present invention, it is preferable that the reflectance adjusting member is any one of a white polyethylene terephthalate film, a silver vapor-deposited sheet, and an aluminum vapor-deposited sheet.
With this configuration, it is possible to reduce the display unevenness in the first liquid crystal panel by adjusting the light reflectance to a desired value, and to prevent the liquid crystal device from becoming thick.

In configuring the liquid crystal device of the present invention, a flexible circuit board is connected to the second liquid crystal panel, and the flexible circuit board is shaped so as to surround the second liquid crystal panel. It is preferable to provide a reflectance adjusting member by giving the flexible circuit board around the second liquid crystal panel a reflection function or a light shielding function.
By configuring in this way, the reflectance of light can be adjusted without increasing the number of components, so that the manufacturing process is not increased and the increase in production cost can be suppressed.

In configuring the liquid crystal device of the present invention, it is preferable to arrange the reflectance adjusting member also on the first liquid crystal panel side.
By comprising in this way, it can prevent effectively that display nonuniformity is visually recognized by the reflectance of light in each of the 1st liquid crystal panel and the 2nd liquid crystal panel differing.

In configuring the liquid crystal device of the present invention, it is preferable that the entire second liquid crystal panel overlaps with a part of the first liquid crystal panel in a planar manner.
With this configuration, even if the liquid crystal device for double-sided display has a configuration in which one of the liquid crystal panels entirely overlaps with a part of the other liquid crystal panel, the light reflectance of each liquid crystal panel is different. Therefore, it is possible to effectively prevent display unevenness from being visually recognized.

Still another embodiment of the present invention is an electronic apparatus including any one of the liquid crystal devices described above.
In other words, since the liquid crystal device for double-sided display in which the reflection of shadows due to the difference in light reflectance is reduced is provided, an electronic device with less display defects can be provided.

Hereinafter, embodiments of the liquid crystal device and the electronic apparatus of the present invention will be specifically described with reference to the drawings. However, this embodiment shows one aspect of the present invention and does not limit the present invention, and can be arbitrarily changed within the scope of the present invention.
In addition, what is attached | subjected with the same code | symbol in each figure has shown the same member, and while omitting description suitably, in each figure, one part member may be abbreviate | omitted suitably.

[First Embodiment]
The first embodiment includes a first liquid crystal panel that holds a liquid crystal material, a second liquid crystal panel that holds the liquid crystal material and is disposed so as to partially overlap the first liquid crystal panel, And a lighting device disposed between the first liquid crystal panel and the second liquid crystal panel.
In such a liquid crystal device, only light having a predetermined polarization direction is incident on the second liquid crystal panel side between the second liquid crystal panel and the illumination device, and other polarized light is emitted. A reflective polarizing plate for reflecting light having a direction toward the first liquid crystal panel, and a non-existing region of the reflective polarizing plate on the second liquid crystal panel side of the lighting device, at least adjacent to the reflective polarizing plate The region to be provided is provided with a reflectance adjusting member different from the reflective polarizing plate for bringing the reflectance of light in the region close to the reflectance of light in the region where the reflective polarizing plate exists.

Hereinafter, as the liquid crystal device according to the first embodiment, for a double-sided display having a configuration in which a reflective polarizing plate is provided between the lighting device and the first liquid crystal panel and between the lighting device and the second liquid crystal panel. The liquid crystal device will be described as an example.
In this embodiment, a liquid crystal device using an active matrix type liquid crystal panel provided with a TFT element (Thin Film Transistor) will be described. However, an active matrix type liquid crystal panel provided with a TFD element (Thin Film Diode). In addition, various liquid crystal panels such as a passive matrix liquid crystal panel that does not include a switching element can be used. In the following description, a liquid crystal panel refers to a state in which a liquid crystal material is injected between a pair of substrates bonded with a sealing material, and a flexible circuit board or an electronic component is connected. A state in which an illumination device such as a light source is attached is referred to as a liquid crystal device.

1. Basic Configuration First, a basic configuration of a liquid crystal device for front and back side display according to the present embodiment will be described with reference to a cross-sectional view of FIG.
As shown in FIG. 1, in the liquid crystal device 10 of this embodiment, a first liquid crystal panel 20 </ b> A and a second liquid crystal panel 20 </ b> B are arranged back to back with the illumination device 11 in between. In addition, the first liquid crystal panel 20A and the second liquid crystal panel 20B are arranged so as to partially overlap in a plane. Further, first and second reflective polarizing plates 15a and 15b described later are provided between the illumination device 11 and the first liquid crystal panel 20A and the second liquid crystal panel 20B, respectively.
Then, a part of the light emitted from the illumination device 11 travels toward the second liquid crystal panel 20B, and the second reflective polarizing plate disposed between the illumination device 11 and the second liquid crystal panel 20B. Enter 15b. At this time, light having a predetermined polarization direction passes through the second reflective polarizing plate 15b as it is and enters the second liquid crystal panel 20B, while light having another polarization direction is second reflected. The light is reflected by the polarizing plate 15b and travels toward the first liquid crystal panel 20A.

On the other hand, since the first reflective polarizing plate 15a is also provided between the first liquid crystal panel 20A and the illuminating device 11, the second liquid crystal is also used for light traveling toward the first liquid crystal panel 20A. Similar to the light traveling toward the panel 20B, only light having a predetermined polarization direction is transmitted through the first reflective polarizing plate 15a and incident on the first liquid crystal panel 20A. The light it has is reflected by the first reflective polarizing plate 15a and travels again toward the second liquid crystal panel 20B.
While such reflection is repeated, light enters the liquid crystal panel at a timing at which the polarization direction coincides with the transmission axis of the reflective polarizing plate, so that light can be used efficiently without waste.

In the liquid crystal device having the above-described structure, light incident on each liquid crystal panel passes through the transparent transparent electrode portion, passes through the colored layer, the liquid crystal material, and the like and exits from the liquid crystal panel. Transparent display is performed.
In the liquid crystal device of the present embodiment, when transmissive display is performed, the light emitted from the light source is effectively used without waste while minimizing the use area of the reflective polarizing plate, which has a relatively high production cost. A bright image can be displayed on each of the first liquid crystal panel and the second liquid crystal panel.
When the liquid crystal panel includes a light reflecting film, external light such as sunlight or room illumination light enters the liquid crystal panel from the counter substrate side, and passes through the colored layer or the liquid crystal material. Reflection display can also be performed by reaching the reflection film, being reflected there, passing through the liquid crystal material or the colored layer again, and exiting from the liquid crystal panel.

2. Next, the first liquid crystal panel and the second liquid crystal panel used in the liquid crystal device according to the present embodiment will be described. Here, FIG. 2 shows a cross-sectional view of the liquid crystal panel 20 used in the liquid crystal device of the present embodiment.
As shown in FIG. 2, in the liquid crystal panel, the counter substrate 30 and the element substrate 60 are bonded together by a sealing material (not shown) at their peripheral portions, and the counter substrate 30, the element substrate 60, and the seal are further bonded. The liquid crystal material 21 is enclosed in a gap surrounded by the material.

The counter substrate 30 is formed of glass, plastic, or the like, and on the counter substrate 30, a color filter, that is, colored layers 37r, 37g, and 37b, and a counter layer formed on the colored layers 37r, 37g, and 37b. An electrode 33 and an alignment film 45 formed on the counter electrode 33 are provided. In addition, an insulating layer 41 for optimizing retardation is provided between the colored layers 37r, 37g, and 37b and the counter electrode 33 in the reflective region R.
Here, the counter electrode 33 is a planar electrode formed over the entire surface of the counter substrate 30 with ITO (indium tin oxide) or the like. In addition, the colored layers 37r, 37g, and 37b are disposed at positions facing the pixel electrode 63 on the element substrate 60 side, such as R (red), G (green), B (blue), or C (cyan), M (magenta), and Y. A color filter element of any color such as (yellow) is provided. A black mask or black matrix, that is, a light shielding film 39 is provided next to the colored layers 37 r, 37 g, and 37 b and at a position that does not face the pixel electrode 63.

The element substrate 60 facing the counter substrate 30 is formed of glass, plastic, or the like. On the element substrate 60, a TFT element 69 as an active element functioning as a switching element and a transparent insulating film 81 are sandwiched. And the pixel electrode 63 formed in the upper layer of the TFT element 69.
Here, the pixel electrode 63 is formed as a light reflection film 79 (63a) for performing reflective display in the reflective region R, and is formed as a transparent electrode 63b with ITO or the like in the transmissive region T. . The light reflection film 79 as the pixel electrode 63a is formed of a light reflective material such as Al (aluminum) or Ag (silver). An alignment film 85 made of a polyimide-based polymer resin is formed on the pixel electrode 63, and a rubbing process as an alignment process is performed on the alignment film 85.

  Further, a phase difference plate 47 is formed on the outer surface (that is, the upper side in FIG. 2) of the counter substrate 30, and a polarizing plate 49 is further formed thereon. Similarly, a retardation plate 87 is formed on the outer surface of the element substrate 60 (that is, the lower side in FIG. 2), and a polarizing plate 89 is further formed thereunder. Further, a backlight unit (not shown) is disposed below the element substrate 60.

The TFT element 69 includes a gate electrode 71 formed on the element substrate 60, a gate insulating film 72 formed on the entire area of the element substrate 60 on the gate electrode 71, and the gate insulating film 72 interposed therebetween. A semiconductor layer 70 formed above the gate electrode 71, a source electrode 73 formed on one side of the semiconductor layer 70 via a contact electrode 77, and a contact electrode 77 on the other side of the semiconductor layer 70. And a drain electrode 66 formed through the electrode.
The gate electrode 71 extends from the gate bus wiring (not shown), and the source electrode 73 extends from the source bus wiring (not shown). Further, a plurality of gate bus lines extend in the horizontal direction of the element substrate 60 and are formed in parallel in the vertical direction at equal intervals, and the source bus lines cross the gate bus lines with the gate insulating film 72 interposed therebetween. A plurality of lines extending in the vertical direction are formed in parallel in the horizontal direction at equal intervals.
Such a gate bus wiring is connected to a liquid crystal driving IC (not shown) and functions as, for example, a scanning line, while a source bus wiring is connected to another driving IC (not shown), for example, a signal line. Acts as
The pixel electrode 63 is formed in a region excluding a portion corresponding to the TFT element 69 in a rectangular region defined by the gate bus wiring and the source bus wiring intersecting each other.

Here, the gate bus wiring and the gate electrode can be formed of chromium, tantalum, or the like, for example. The gate insulating film is formed of, for example, silicon nitride (SiN _x ), silicon oxide (SiO _x ), or the like. Further, the semiconductor layer can be formed of, for example, doped a-Si, polycrystalline silicon, CdSe, or the like. Further, the contact electrode can be formed of, for example, a-Si, and the source electrode and the source bus wiring and the drain electrode integrated therewith can be formed of, for example, titanium, molybdenum, aluminum, or the like.

The organic insulating film 81 is formed over the entire area of the element substrate 60 so as to cover the gate bus lines, the source bus lines, and the TFT elements. However, a contact hole 83 is formed in a portion corresponding to the drain electrode 66 of the organic insulating film 81, and the pixel electrode 63 and the drain electrode 66 of the TFT element 69 are electrically connected at the contact hole 83.
In addition, in the organic insulating film 81, a resin film having a concavo-convex pattern composed of a regular or irregular repetitive pattern of peaks and valleys is formed as a scattering shape in a region corresponding to the reflective region R. Has been. As a result, the light reflection film 79 (63a) laminated on the organic insulating film 81 also has a light reflection pattern composed of an uneven pattern. However, this uneven pattern is not formed in the transmission region T.

3. As shown in FIG. 3 (a), the lighting device disposed between the first liquid crystal panel and the second liquid crystal panel includes a light source 12 such as an LED at the end, and An illumination device including a light guide plate 13 for introducing light emitted from the light source 12 into each liquid crystal panel is generally used. In the illuminating device 11 including the light guide plate 13, a side surface of the light guide plate 13, that is, a surface that does not face the first and second liquid crystal panels, includes a light reflection film, a light shielding film, and the like for preventing light leakage. It is preferable.
On the other hand, as another example of the illumination device, as shown in FIG. 3B, an illumination device in which a plurality of cold cathode fluorescent tubes 14 are arranged in a plane can be used.

4). Reflective Polarizing Plate In addition, as shown in FIG. 1, the liquid crystal device according to the present embodiment includes an illumination device 11 between the illumination device (light guide plate) 11 and the first liquid crystal panel 20A and the second liquid crystal panel 20B. Reflective polarizing plates 15a and 15b are provided for allowing only light having a predetermined polarization direction out of the light 19 emitted from the light to enter the liquid crystal panel as it is and reflecting light having other polarization directions. By providing such a reflective polarizing plate, a part of light necessary for transmissive display can be transmitted and transmissive display can be performed, while other light is reflected and incident on the other liquid crystal panel side. It can also be used when performing transmissive display on the liquid crystal panel side. Therefore, it is possible to make a bright image visible by effectively using the light emitted from the light source without waste.
Further, in the liquid crystal device of the present invention, in order to suppress an increase in production cost, such a reflective polarizing plate is provided corresponding only to a region where the liquid crystal panel exists between the lighting device and each liquid crystal panel. Yes.
As such a reflective polarizing plate, for example, a cholesteric liquid crystal polymer film (manufactured by Nitto Denko Corporation: NIPOX) can be used.

5. Reflectivity adjusting member Further, as shown in FIG. 1, the liquid crystal device according to the present embodiment includes a first liquid crystal device between a lighting device (light guide plate) 11 and the first liquid crystal panel 20A and the second liquid crystal panel 20B. In the non-existing region of the polarizing plate 15a and the second reflective polarizing plate 15b, at least in the region adjacent to the reflective polarizing plates 15a and 15b, the reflectance of light in the region and the reflectance of light in the reflective polarizing plate The reflectance adjusting members 17a and 17b, which are different from the reflective polarizing plate, are provided.
That is, in the liquid crystal device of the present invention, the first liquid crystal panel is disposed so as to overlap in a plane across the existing region and the non-existing region of the reflective polarizing plate. The reflectance of light on the back side of the display surface of the liquid crystal panel is different. Therefore, with this configuration, the area where the reflective polarizing plate is not present in the region adjacent to the reflective polarizing plate advances toward one liquid crystal panel while reducing the sticking area of the relatively expensive reflective polarizing plate. The reflectance of the light toward the other liquid crystal panel can be brought close to the reflectance of the light in the reflective polarizing plate to prevent the reflectance from changing abruptly. Accordingly, it is possible to prevent the display unevenness due to the difference in the light reflectance from being visually recognized on the display surface of the liquid crystal panel opposite to the side on which the reflectance adjusting member is provided with the illumination device interposed therebetween. .

  Here, referring to FIG. 4 to FIG. 5, the light emitted from the illumination device 11 is taken by taking the reflective polarizing plate 15 b and the reflectance adjusting member 17 b provided on the second liquid crystal panel 20 B side as an example. A state of entering each liquid crystal panel 20A and 20B will be described. As shown in FIGS. 4 to 5, as described above, the second reflective polarizing plate 15b is provided between the lighting device 11 and the second liquid crystal panel 20B so as to keep the production cost low. It is disposed only in the region 5a where the panel 20B exists. Therefore, the reflectance of light differs between the existence area 5a of the second reflective polarizing plate 15b and the other non-existence area 5b. Then, the light incident on the first liquid crystal panel 20A including the reflected light becomes partially non-uniform, and the reflectance at the boundary portion changes abruptly, and the display surface of the first liquid crystal panel 20A The display unevenness is visually recognized. Therefore, by providing the predetermined reflectance adjusting member 17b in the region 5c adjacent to the second reflective polarizing plate 15b in the non-existing region 5b of the second reflective polarizing plate 15b, the light reflectance changes rapidly. Can be prevented. Therefore, it is possible to effectively prevent the display unevenness due to the difference in light reflectance from being visually recognized on the display surface of the first liquid crystal panel 20A.

For example, as shown in FIG. 4A, a light reflection film 79 made of aluminum or the like is provided in the non-existing region 5b of the second reflective polarizing plate 15b on the second liquid crystal panel 20B side of the illumination device 11. The reflectance of the light reflecting film 79 is larger than the reflectance of light in the region 5a where the second reflective polarizing plate 15b is present. In this case, the reflectance of light in the non-existing region 5b and at least the region 5c adjacent to the second reflective polarizing plate 15b is made smaller than the reflectance of the light reflecting film 79, so that the second The reflectance adjusting member 17b is provided so as to approach the reflectance of the reflective polarizing plate 15b.
As such a reflectance adjustment member, for example, as shown in FIG. 4B, the reflectance adjustment member 17b is made of a member lower than the reflectance of the light reflection film 79 and partially includes the opening region 17X. Can be used. More specifically, by using a black material such as carbon, which is a material for forming a light-shielding film that is generally provided in a liquid crystal panel, on the side closer to the lighting device than the light reflecting film in the lighting device (light guide plate). On the other hand, it can be set as the reflectance adjustment member which formed the film | membrane by patterning so that an opening area | region may be included. By providing such a reflectance adjusting member, the reflectance of the light reflecting film can be reduced in a region adjacent to the second reflective polarizing plate. Therefore, the difference between the reflectance of light in the region where the second reflective polarizing plate exists and the reflectance of light in the region including the reflectance adjusting member, and the reflectance and light of the light in the region including the reflectance adjusting member. The light reflectivity and difference in the region having only the reflective film are smaller than the light reflectivity and difference in the region having only the second reflective polarizing plate and the light reflectivity and difference in the region having only the light reflective film, respectively. can do. Accordingly, since there is no boundary portion where the reflectance of light greatly changes, display unevenness is hardly visible on the display surface of the first liquid crystal panel.

As another example, as shown in FIG. 5A, a light absorbing member such as a light shielding film is provided in the non-existing region 5a of the second reflective polarizing plate 15b on the second liquid crystal panel 20B side of the lighting device 11. When 88 is provided, the reflectance of light in the arrangement region 5b of the light absorbing member 88 is smaller than the reflectance of light in the region 5a of the second reflective polarizing plate 15b. In this case, the light reflectance in at least the region 5 c adjacent to the second reflective polarizing plate 15 b in the non-existing region 5 b is larger than the light reflectance in the arrangement region 5 b of the light absorbing member 88. And it is set as the structure provided with the reflectance adjustment member 17b which approaches the reflectance of the light in the area | region 5a of the 2nd reflective polarizing plate 15b.
As such a reflectance adjusting member, for example, as shown in FIG. 5B, the reflectance adjusting member 17b is made of a member higher than the reflectance of the light absorbing member 88 and partially includes the opening region 17X. Can be used. More specifically, the second reflective polarizing plate is formed by forming a film at the same position as the above-described reflectance adjusting member using aluminum, silver, or the like generally used for reflecting light. It is possible to increase the reflectance of light in the adjacent region. Therefore, similarly to the above, it is possible to eliminate the boundary portion where the reflectance of light greatly changes, and display unevenness is hardly observed on the display surface of the first liquid crystal panel. In addition, a reflectance adjusting member made of such a material is a preferable mode because it can be formed as a thin film and the liquid crystal device is not enlarged.

As shown in FIGS. 4 and 5, when the reflectance adjusting member 17b is disposed only in the region 5c adjacent to the existing region 5a of the second reflective polarizing plate 15b, the reflectance adjusting member 17b is disposed. The reflectance of the light in the region 5c is determined by the reflectance of the light in the region 5a of the second reflective polarizing plate 15b and the reflectance of the light in the region where the reflectance adjusting member 17b is not disposed in the non-existing region 5b. An intermediate value is preferred.
This is because the reflectance of light in the existing region of the reflective polarizer and the reflectance of light in the non-existing region can be changed in steps at the same rate. This is because the light reflectance does not change abruptly even at the boundary portion. Therefore, display unevenness on the display surface of the first liquid crystal panel can be made less visible.
More specifically, for example, in the case where the reflectance of the reflective polarizing plate is 50% and a light reflecting film having a reflectance of 80% is provided, the reflectance of light in the region where the reflectance adjusting member is disposed is set. It is preferable to make it about 65%.

In addition, the reflectance adjustment member mentioned above becomes a structure which adjusts the reflectance of the light in the arrangement | positioning area | region of a reflectance adjustment member by covering a part of the member on the basis of the reflectance of the member which exists from the first. However, it is not limited to such a configuration. That is, if the reflectance itself of the reflectance adjusting member is a member that shows a value that is about the intermediate value between the reflectance of the reflective polarizing plate and the reflectance of the other region, a predetermined opening as shown in FIG. By using the reflectance adjusting member 17b that does not have a region, similar to the configuration described above, a sudden change in reflectance is adjusted, and display unevenness on the display surface of the first liquid crystal panel 20A is visually recognized. Can be made difficult.
As such a reflectance adjusting member, for example, a white polyethylene terephthalate film can be used. That is, by disposing a polyethylene terephthalate film whose whiteness is adjusted so as to exhibit a desired reflectance in a region adjacent to the second reflective polarizing plate, an existing region and a non-existing region of the second reflective polarizing plate In the meantime, a region where the difference in reflectance can be reduced can be formed.

Further, regarding the arrangement position of the reflectance adjusting member, it is necessary to arrange at least in a region adjacent to the second reflective polarizing plate, but as shown in FIG. 7, the entire non-existing region 5b of the second reflective polarizing plate 15b. It is preferable to arrange in.
The reason for this is that the light reflectance in the non-existing region can be made uniform while reducing the difference in light reflectance between the existing region and the non-existing region of the second reflective polarizing plate. This is because it is possible to more effectively prevent the display unevenness from being visually recognized on the display surface of the first liquid crystal panel by reducing the number of portions.

Further, when the reflectance adjusting member 17b is arranged in this way, the light reflectance in the arrangement region 5b of the reflectance adjusting member 17b is set to the light reflectance in the existence region 5a of the second reflective polarizing plate 15b. It is preferable to match.
This is because the light reflectance in the existing region and the non-existing region of the second reflective polarizing plate can be made uniform, and the display unevenness due to the different light reflectance on the display surface of the first liquid crystal panel. This is because it can be prevented from being visually recognized.
Such a reflectance adjusting member can be obtained by adjusting and providing so as to match the reflectance of the reflective polarizing plate while using the materials described above.

Needless to say, the first reflective polarizing plate and the first reflectance adjusting member provided between the lighting device and the first liquid crystal panel are the same as those described above. It can be set as the structure similar to a 2nd reflectance adjustment member. Further, as described above, the reflectance adjusting member is not limited to the aspect formed in the lighting device (light guide plate), and can be disposed at a predetermined position as an independent plate-like reflectance adjusting plate.
And if it is the liquid crystal device for double-sided display of this embodiment, since it has the 1st and 2nd reflective polarizing plates and the 1st and 2nd reflectance adjustment members on both sides of an illuminating device, respectively, The light emitted from the lighting device can be effectively used without waste, and the display unevenness due to a sudden change in reflectance is effectively prevented from being visually recognized on the display surfaces of the first and second liquid crystal panels. The liquid crystal device can be obtained.

[Second Embodiment]
In the second embodiment of the present invention, a flexible circuit board connected to the second liquid crystal panel as a reflectance adjusting member in the liquid crystal device of the first embodiment has a shape surrounding the periphery of the second liquid crystal panel. In addition, this is a liquid crystal device for double-sided display in which a flexible circuit board around the second liquid crystal panel is provided with a reflection function or a light shielding function and is used as a reflectance adjustment member.
The following description will focus on the reflectance adjustment member different from that of the first embodiment, and description of points common to the first embodiment will be omitted as appropriate.

As shown in FIGS. 8A to 8B, the liquid crystal device 10 ′ for double-sided display according to the present embodiment includes a flexible circuit board 93b connected to the second liquid crystal panel 20B as the reflectance adjustment member 17b. The flexible circuit board 93b around the second liquid crystal panel 20B is provided with a reflection function or a light shielding function while being shaped to surround the second liquid crystal panel 20A provided with the second reflective polarizing plate 15b. The reflectance adjusting member 17b configured as described above is provided. With such a reflectance adjustment member, it is possible to efficiently use light efficiently by reflecting a predetermined ratio of light and preventing other light from leaking to the outside. In addition, since the number of parts is not increased, the reflectance can be adjusted without lowering the production efficiency and cost, and the display unevenness on the display surface of the first liquid crystal panel can be made less visible.
More specifically, an illumination device in a flexible circuit board in a region adjacent to the second reflective polarizing plate while using a flexible circuit substrate having a shape that also exists in a region adjacent to at least the second reflective polarizing plate. By performing silk screen printing of silver, aluminum or the like on the side surface, a reflectance adjusting member capable of exhibiting a desired reflectance and light shielding rate can be formed.
FIG. 8A is a schematic view of the liquid crystal device 10 ′ according to the present embodiment as viewed from the side, and FIG. 8B shows the liquid crystal device 10 ′ of FIG. It is the top view seen from.

As described in the first embodiment, the flexible circuit board as the reflectance adjusting member needs to be present at least in a region adjacent to the second reflective polarizing plate, that is, around the second liquid crystal panel. In the case of the arrangement as described above, it is preferable that the reflectance adjusting member is adjusted so as to show the reflectance of light that is an intermediate value between the existing region and the non-existing region of the second reflective polarizing plate.
Further, in order to make display unevenness less visible, as shown in FIGS. 9A to 9B, the display unevenness 5 b is made to exist in the entire non-existing region 5 b of the second reflective polarizing plate 15 b and the reflectance adjusting member 17. It is preferable that the reflectance of light in the arrangement region 5b of the second electrode coincides with the reflectance of light in the region 5a of the second reflective polarizing plate 15b.

[Third Embodiment]
According to a third embodiment of the present invention, in the liquid crystal device according to the first embodiment or the second embodiment, both surfaces of the second liquid crystal panel are arranged so as to overlap with a part of the first liquid crystal panel in a plane. It is a liquid crystal device for display.
The following description will focus on the arrangement positions of the first and second liquid crystal panels, which are different from the points described in the first and second embodiments, and description of points already described will be omitted as appropriate.

  As shown in FIG. 10, in the liquid crystal device 10 ″ of the present embodiment, the first liquid crystal panel 20 </ b> A and the second liquid crystal panel 20 </ b> B are arranged back to back with the illumination device 11 in between. The entire panel 20B is disposed so as to overlap with a part of the first liquid crystal panel 20A. Further, first and second reflective polarizing plates 15a and 15b are provided between the illumination device 11 and the first liquid crystal panel 20A and the second liquid crystal panel 20B, respectively.

In addition, in the region where the second reflective polarizing plate 15b is not present between the lighting device (light guide plate) 11 and the second liquid crystal panel 20B, at least in the region adjacent to the reflective polarizing plate 15b, A reflectance adjusting member 17 different from that of the reflective polarizing plate is provided to make the light reflectance close to the light reflectance of the reflective polarizing plate.
For example, as shown in FIG. 10, the reflectance adjusting member 17 includes a reflectance adjusting member (configuration shown in FIG. 4B or FIG. 5B) 17 having the configuration described in the first embodiment. can do. As another example, as shown in FIG. 11, the reflectance adjusting member (configuration shown in FIG. 8B) 17 using the flexible circuit board 93b as described in the second embodiment may be used. it can.

As for the arrangement position of the reflectivity adjusting member, as shown in FIG. 10, the reflectivity adjusting member 17b can be arranged only in the region 5c adjacent to the existing region 5a of the second reflective polarizing plate 15b. As shown in FIG. 12, the second reflective polarizing plate 15b can be disposed over the entire non-existing region 5b.
In addition, the relationship between the reflectance of the reflectance adjusting member and the reflectance of the reflective polarizing plate can be configured by appropriately selecting the aspect described in the first embodiment and the second embodiment.

  In the liquid crystal device according to the present embodiment configured as described above, even if the whole of one liquid crystal panel overlaps with a part of the other liquid crystal panel in a plan view, Reflecting the reflectance of light traveling to one liquid crystal panel to the other liquid crystal panel in a region adjacent to the reflective polarizing plate in a region adjacent to the reflective polarizing plate while reducing the pasting area. It is possible to prevent the reflectance from changing rapidly by approaching the reflectance of light in the polarizing plate. Accordingly, it is possible to prevent the display unevenness due to the difference in the light reflectance from being visually recognized on the display surface of the liquid crystal panel opposite to the side on which the reflectance adjusting member is provided with the illumination device interposed therebetween. .

[Fourth Embodiment]
4th Embodiment of this invention is an electronic device provided with the liquid crystal device in any one of 1st Embodiment-3rd Embodiment.
FIG. 13 is a schematic configuration diagram showing the overall configuration of the electronic apparatus of the present embodiment. The electronic apparatus includes a liquid crystal panel 20 provided in the liquid crystal device and a control unit 200 for controlling the liquid crystal panel 20. In FIG. 13, the liquid crystal panel 20 is conceptually divided into a panel structure 20 </ b> A and a drive circuit 20 </ b> B composed of a semiconductor element (IC) or the like. The control means 200 also includes a display information output source 201, a display processing circuit 202, a power supply circuit 203, and a timing generator 204.
The display information output source 201 includes a memory composed of a ROM (Read Only Memory) or a RAM (Random Access Memory), a storage unit composed of a magnetic recording disk, an optical recording disk, etc. And is configured to supply display information to the display processing circuit 202 in the form of an image signal having a predetermined format based on various clock signals generated by the timing generator 204.

The display processing circuit 202 includes various well-known circuits such as a serial-parallel conversion circuit, an amplification / inversion circuit, a rotation circuit, a gamma correction circuit, and a clamp circuit, and executes processing of input display information to display the image. Information is supplied together with the clock signal CLK to the drive circuit 20B. Furthermore, the drive circuit 20B can include a first electrode drive circuit, a second electrode drive circuit, and an inspection circuit. Further, the power supply circuit 203 has a function of supplying a predetermined voltage to each of the above-described components.
In the electronic device according to the present embodiment, the reflectance adjustment member is disposed at least in a region adjacent to the reflective polarizing plate while reducing the pasting area of the relatively expensive reflective polarizing plate as much as possible. Therefore, it is possible to provide an electronic device in which display unevenness is difficult to be visually recognized.

  According to the present invention, in the liquid crystal device for double-sided display in which the first and second liquid crystal panels are arranged back to back so as to overlap each other with the illumination device interposed therebetween, the predetermined reflectance adjusting member By providing the liquid crystal device, it is possible to provide a liquid crystal device in which the difference in reflectance at the boundary portion is reduced while the light is efficiently used effectively, and the visibility of display unevenness is reduced. Accordingly, liquid crystal devices including TFD elements and other various liquid crystal devices and electronic devices such as mobile phones and personal computers, liquid crystal televisions, viewfinder type / monitor direct view type video tape recorders, car navigation devices, The present invention can be widely applied to pagers, electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, electronic devices equipped with touch panels, and the like.

It is the schematic which shows the liquid crystal device for double-sided display of 1st Embodiment. It is a schematic sectional drawing of the liquid crystal panel used for a liquid crystal device. (A)-(b) is a figure which shows the example of an illuminating device. (A)-(b) is a figure which shows the structural example of the reflectance adjustment member in the case of providing a light reflection film in the non-existing area | region of a reflective polarizing plate. (A)-(b) is a figure which shows the structural example of the reflectance adjustment member in the case of providing a light absorption film in the non-existing area | region of a reflective polarizing plate. It is a figure which shows another structure of a reflectance adjustment member. It is a figure which shows the example which has arrange | positioned the reflectance adjustment member in the whole surface of the non-existing area | region of a reflective polarizing plate. (A)-(b) is a figure provided in order to demonstrate the structure of the liquid crystal device for double-sided display of 2nd Embodiment. (A)-(b) is a figure which shows the example which has arrange | positioned the reflectance adjustment member using a flexible circuit board in the non-existing area | region whole surface of a reflective polarizing plate. (A)-(b) is a figure provided in order to demonstrate the structure of the liquid crystal device for double-sided display of 3rd Embodiment. (A)-(b) is a figure which shows the structural example of the liquid crystal device provided with the reflectance adjustment member using a flexible circuit board. It is a figure which shows the example which has arrange | positioned the reflectance adjustment member in the whole surface of the non-existing area | region of a reflective polarizing plate. It is a block diagram which shows schematic structure of the electronic device of 4th Embodiment. It is a figure provided in order to demonstrate the structure of the conventional liquid crystal device.

Explanation of symbols

5a: Reflecting polarizing plate existence region, 5b: Reflecting polarizing plate non-existing region, 5c: Adjacent region, 10: Liquid crystal device, 11: Illumination device, 12: Light source: 13: Light guide plate, 14: Fluorescent tube, 15.15a. 15b: reflective polarizing plate, 17, 17a, 17b: reflectance adjusting member, 17X: aperture region, 20A, 20B: liquid crystal panel, 79: light reflecting film, 88: light absorbing member, 93: flexible circuit board

Claims (10)

A first liquid crystal panel holding a liquid crystal material;
A second liquid crystal panel that holds the liquid crystal material and is arranged so that at least a part thereof overlaps the first liquid crystal panel in a plane;
A lighting device disposed between the first liquid crystal panel and the second liquid crystal panel;
In a liquid crystal device for double-sided display including
Between the second liquid crystal panel and the illuminating device, only light having a predetermined polarization direction out of the light emitted from the illuminating device is incident on the second liquid crystal panel side and other polarization directions. A reflective polarizing plate for reflecting light having the above to the first liquid crystal panel side,
In the non-existing region of the reflective polarizing plate on the second liquid crystal panel side of the lighting device, at least in the region adjacent to the reflective polarizing plate, the reflectance of the light in the region is determined. A liquid crystal device, comprising: a reflectance adjusting member different from the reflective polarizing plate, in order to approach the reflectance of light in the existing region.   2. The liquid crystal device according to claim 1, wherein the first liquid crystal panel is disposed so as to overlap in a plane across an existing region and a non-existing region of the reflective polarizing plate.   The liquid crystal device according to claim 1, wherein the reflectance adjusting member is disposed over the entire non-existing region of the reflective polarizing plate.   When the reflectance adjusting member is disposed over the entire non-existing region of the reflective polarizing plate, the reflectance of light in the region is matched with the reflectance of light in the existing region of the reflective polarizing plate. Item 4. The liquid crystal device according to item 3.   When the reflectance adjusting member is disposed only in a region adjacent to the reflective polarizing plate, the reflectance of light in the region where the reflectance adjusting member is disposed is defined as the reflectance of light in the region where the reflective polarizing plate exists. 3. The liquid crystal device according to claim 1, wherein the liquid crystal device has an intermediate value between the reflectance of light in a region where the reflectance adjusting member is not disposed in the non-existing region.   The liquid crystal device according to any one of claims 1 to 5, wherein the reflectance adjusting member is any one of a white polyethylene terephthalate film, a silver vapor deposition sheet, and an aluminum vapor deposition sheet.   A flexible circuit board is connected to the second liquid crystal panel, the flexible circuit board is shaped to surround the second liquid crystal panel, and the flexible circuit board around the second liquid crystal panel is formed. The liquid crystal device according to claim 1, wherein a reflectance adjusting member is provided by providing a reflective function or a light shielding function to the liquid crystal device.   The liquid crystal device according to claim 1, wherein the reflectance adjusting member is also disposed on the first liquid crystal panel side.   The liquid crystal device according to claim 1, wherein the second liquid crystal panel entirely overlaps with a part of the first liquid crystal panel. An electronic apparatus comprising the liquid crystal device according to claim 1.

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