JP4682502B2 - Electro-optical device and electronic apparatus including the electro-optical device - Google Patents

Description

  The present invention relates to an electro-optical device and an electronic apparatus including the electro-optical device, and more particularly to an electro-optical device including display panels on both sides and an electronic apparatus including the electro-optical device.

  2. Description of the Related Art Conventionally, a double-sided liquid crystal display device in which two liquid crystal display devices are arranged back to back on an inner surface and an outer surface of an information portable terminal such as a cellular phone or a PDA (Personal Digital Assistant) has been used. Yes. In such a double-sided liquid crystal display device, the first and second liquid crystal panels disposed on the front and back, the first and second LEDs serving as the light sources of the first and second liquid crystal panels, and the first and second LEDs The first and second light guide plates that diffuse the light from the LEDs and guide the light to the first and second liquid crystal panels, respectively, and the first and second LEDs pass through the first and second light guide plates. What is comprised with the 1st and 2nd reflection sheet | seat which each reflects light is well-known (for example, refer patent document 1).

Japanese Patent Laid-Open No. 2002-244133, FIG.

  However, in the conventional double-sided liquid crystal display device, the first and second reflective sheets are used. However, in order to reduce the thickness of the double-sided liquid crystal display device, the reflective sheet is made common and the reflective surfaces are formed on both sides. When the reflective sheet is used, the light emitted from the first LED or the second LED passes through the reflective sheet, and the leaked light enters the second or first liquid crystal display panel. As a result, there is a problem that display unevenness is visually recognized by an observer.

  The present invention has been made in view of the above, and provides an electro-optical device having no display unevenness and an electronic apparatus including the electro-optical device when a display panel is provided on both sides and a reflecting member is used in common. With the goal.

In order to solve the above-described problems and achieve the object, the present invention provides an electro-optical device having display panels on both sides, including first and second light sources, and illuminating light on the first and second surfaces. First and second illuminating means respectively emitting to the side, a reflecting member provided between the first illuminating means and the second illuminating means, and having reflecting surfaces formed on both surfaces, and the first illuminating means A normally white first display panel provided on the first surface side with the means as a backlight and capable of displaying an image, and the first panel on the second surface side with the second illumination means as a backlight. And a second display panel that is smaller in outer shape than the first panel and capable of displaying an image, wherein the first illumination means emits illumination light emitted from the first light source. Including a first light guide plate that guides to the first surface side, The first light source is disposed to face the end surface of the first light guide plate, and the second illumination means guides the illumination light emitted from the second light source to the second surface side. A second light guide plate, wherein the second light source is disposed to face an end surface of the second light guide plate, and the first light source has a region for displaying an image of the second display panel; An area that does not overlap is disposed in an area that overlaps with the first display panel, and the second light source is disposed in an area that displays an image of the first display panel and an area that overlaps with the second display panel. A light shielding member is disposed between the second light source and the reflection member, and illumination light emitted from the second light source by the reflection sheet and the light shielding member is the first display panel. It is characterized by preventing leakage to the side.

According to the above invention, the light shielding member shields the illumination light emitted from the second light source from being transmitted to the first reflective panel through the reflective member shared for the purpose of thinning. Thereby, it is possible to prevent the illumination light emitted from the second light source from passing through the reflecting member and leaking to the first display panel . As a result, it is possible to provide an electro-optical device without display unevenness when display panels are provided on both sides and the reflecting member is shared.

According to a preferred aspect of the present invention, the first illumination unit includes a first light guide plate that guides illumination light emitted from the first light source to the first surface side, and the first light source. Is arranged opposite to the end face of the first light guide plate, and the second illumination means is a second light guide plate for guiding the illumination light emitted from the second light source to the second surface side. Preferably, the second light source is disposed to face the end surface of the second light guide plate. Thereby, when a side edge type backlight is used, the illumination light emitted from the first light source or the second light source passes through the reflecting member and is transmitted to the second display panel or the first display panel. Leakage can be prevented.

  According to a preferred aspect of the present invention, the first display panel is formed larger than the outer shape of the second display panel, and the light shielding member includes the head of the second light source and the reflection. It is desirable to block the leakage of light from the head of the second light source to the first display panel. Thereby, illumination light leaking from the head of the second light source to the first display panel can be prevented.

  According to a preferred aspect of the present invention, it is desirable that the light shielding member is a light shielding tape. Thereby, the light shielding member can be configured with a simple and low-cost structure.

  According to a preferred aspect of the present invention, it is desirable that the first and second light sources are LEDs. Thereby, since LED which is a point light source was used as a light source, while being able to reduce power consumption, a backlight can be reduced in thickness.

  According to a preferred aspect of the present invention, it is preferable that the first display panel is normally white and the second display panel is normally black. Thereby, even when the first display panel is turned off, display unevenness due to light leakage of the second light source can be prevented.

  Moreover, according to a preferable aspect of the present invention, it is desirable that the light shielding tape has a silver color on the first surface side and a white color on the second surface side. Accordingly, it is possible to efficiently shield the illumination light emitted from the first light source or the second light source from being transmitted through the reflecting member and leaking to the second display panel or the first display panel.

  According to a preferred aspect of the present invention, it is desirable that the electronic apparatus is equipped with the above-described electro-optical device. Thereby, when a display panel is provided on both sides and a reflecting member is used in common, an electronic device without display unevenness can be provided.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same. In the following embodiments, a liquid crystal display device will be described as an example, but the electro-optical device according to the present invention is not limited to this. In this specification, a single electro-optical panel or electro-optical module is also referred to as an electro-optical device.

  FIG. 1 is a perspective view of an electronic apparatus 1 on which the electro-optical device according to the present embodiment is mounted. FIG. 1-1 is a diagram showing a state in which a lid is opened, and FIG. 1-2 is a diagram in which the lid is closed. It is a figure of a state. As shown in FIG. 1A, in the electronic device 1, a first display panel (main display panel) 100 is disposed on the inner side of the lid, and a main body 500 connected to the first display panel (a main display panel) so as to be opened and closed by a hinge. A keyboard, various control units, processing units, storage units, etc. are installed. When the lid of the electronic device 1 is closed in the direction of arrow A, a second display panel (sub display panel) 200 is disposed on the outer surface of the lid, as shown in FIG.

  FIG. 2 is a cross-sectional view schematically illustrating the configuration of the electro-optical device according to the present embodiment. The electro-optical device 10 according to the present embodiment is a double-sided liquid crystal display device, and is roughly classified into a first display panel 100 capable of displaying an image and a first display for irradiating the first display panel 100 with illumination light. Illumination means 110, a second display panel 200 having an outer shape smaller than that of the first display panel 100 and capable of displaying an image, and a second illumination for irradiating the second display panel 200 with illumination light. The illumination light of the second LED 211 is disposed between the means 210, the first illumination means 110, and the second illumination means 210, the reflection sheet 300 having a reflection surface formed on both surfaces, and the first LED 211. A light shielding tape 400 is provided for preventing leakage to the display panel 100 side. In the following description, the surface on which the first display panel 100 is disposed is referred to as a first surface, and the surface on which the second display panel 200 is disposed is referred to as a second surface.

The first display panel 100 is an active matrix type color liquid crystal display panel,
It is normally white. The first display panel 100 is configured by enclosing liquid crystal between two upper display substrates 100a and lower display substrates 100b arranged to face each other. The upper display substrate 100a and the lower display substrate 100b are made of glass. On the upper display substrate 100a, a color filter (not shown), a protective layer, a first drive electrode formed of an ITO film, and the like are formed. On the lower display substrate 100b, a switching element such as a TFD or a TFT (not shown), a protective film, a second drive electrode, and the like are formed. A first upper polarizing plate 101 and a second lower polarizing plate 102 are attached to the upper and lower sides of the first display panel 100, respectively.

  The second display panel 200 is a passive matrix type monochrome liquid crystal display panel, which is normally black. The second display panel 200 is configured such that liquid crystal is sealed between two upper display substrates 200a and 200b disposed to face each other. The upper display substrate 200a and the lower display substrate 200b are made of glass. Scan electrodes and data electrodes are formed on the upper display substrate 200a and the lower display substrate 200b. A second upper polarizing plate 201 and a second lower polarizing plate 202 are attached to both surfaces of the second display panel 200, respectively.

  On the second surface side of the first polarizing plate 102, the first illumination unit 110 is disposed. The first illumination unit 110 is mounted on the FPC 120 and includes a first LED 111 (provided in plurality) that is a point light source disposed at a position facing the end surface of the first light guide plate 112. A first light guide plate 112 that leads the illumination light emitted from one LED 111 to the first display panel 100, a first diffusion sheet 113 that diffuses the illumination light emitted from the first light guide plate 112, and And a first prism sheet 114 that polarizes the illumination light diffused by the first diffusion sheet 113.

  Similarly, a second illumination unit 210 is disposed on the first surface side of the second polarizing plate 202. The second illumination unit 210 is mounted on the FPC 220 and has a second LED 211 (a plurality of points) which is a point light source disposed at a position facing the end face of the second light guide plate 212, and a second LED 211. A second light guide plate 212 that leads the illumination light emitted from the two LEDs 211 to the second display panel 200, a second diffusion sheet 213 that diffuses the illumination light emitted from the second light guide plate 212, and And a second prism sheet 214 that polarizes the illumination light diffused by the second diffusion sheet 213.

  Between the first light guide plate 112 and the second light guide plate 212, a reflective sheet 300 having reflective surfaces formed on both sides is disposed. The reflection sheet 300 reflects the leakage light of the first light guide plate 112 to the first surface side, and reflects the leakage light of the second light guide plate 212 to the second surface side. On the first surface side, the illumination light emitted from the first LED 111 is a first light guide plate 112, a first diffusion sheet 113, a first prism sheet 114, and a first lower polarizing plate 102. Then, the light enters the first display panel 110. On the other hand, on the second surface side, the illumination light emitted from the second LED 211 is emitted from the second light guide plate 212, the second diffusion sheet 213, the second prism sheet 214, and the second lower polarization. The light enters the second display panel 200 through the plate 202.

  Here, since the first display panel 100 is disposed on the head of the second LED 211, a part L1 of the illumination light emitted from the second LED 211 passes through the reflection sheet 300. Then, the light may enter the first display panel 100 and be viewed as a bright portion by an observer of the first display panel 100. Since the first display panel 100 is normally white, light leakage from the second LED 212 is easily visually recognized, particularly when the first display panel 100 is not driven (when the light is turned off). Therefore, in this embodiment, a thin-film light-shielding tape 400 is attached to the head of the second LED 212 and the reflective sheet so that the illumination light emitted from the head of the second LED 211 does not leak to the first display panel 100. 300. One surface of the light shielding tape 400 is attached to the head of the second LED 211, and the other surface is attached to the reflection sheet 300. Thereby, the illumination light L1 emitted from the second LED 211 can be prevented from being leaked to the first display panel 100 by being shielded by the light shielding tape 400. For example, “white and silver”, “black and silver”, “silver and white”, “white and silver”, or “white and silver” on both sides of the light shielding tape 400 "Silver color and silver color" can be used, but "silver color and white color" are more preferable because they can efficiently block light.

  FIG. 3 is a plan view for explaining the shape of the light shielding tape 400, and is a plan view of the light shielding tape 400 and the reflection sheet 300 viewed from the second surface side. The light-shielding tape 400 is configured to have a protruding portion 401 so that it can be attached easily, and has a structure in which a plurality of second LEDs 212 are shielded by a single sheet.

  As described above, according to the above-described embodiment, the first display panel 100 and the second illumination means 210 that emit illumination light to the first display panel 100 and the second display panel 200, respectively, have a double-sided surface. The light-shielding tape (light-shielding member) for preventing light emitted from the second LED 211 from leaking to the first display panel 100 in a thin structure in which the reflective sheet 300 having a reflective surface is formed on the thin film. Since 400 is provided, it is possible to prevent light emitted from the second LED 111 from passing through the reflection sheet 300 and leaking to the first display panel 100. As a result, an electro-optical device without display unevenness can be provided.

  Further, according to the present embodiment, the first display panel 100 is formed larger than the outer shape of the second display panel 200, and the light shielding tape 400 is provided between the head of the second LED 211 and the reflection sheet 300. Since light is leaked from the head of the second LED 211 to the first display panel 100, light leaks from the head of the second LED 211 to the first display panel 100. Can be prevented. Further, according to this embodiment, since the light shielding tape 400 is used as the light shielding member, the light shielding member can be configured with a simple and low-cost structure.

  Moreover, according to the present Example, since LED which is a point light source is used as a light source, power consumption can be reduced and a backlight can be reduced in thickness. Further, according to the present embodiment, the first display panel 100 is normally white and the second display panel is normally black. Therefore, even when the first display panel 100 is turned off, the first display panel 100 is normally white. Display unevenness due to light leakage of the second LED 211 can be prevented. In addition, according to the present embodiment, the light shielding tape 400 has the first surface side silver and the second surface side white, so that the light can be efficiently shielded.

  In the above embodiment, the first display panel 100 is disposed on the head of the second LED 211. However, the present invention is not limited to such a configuration, and the head of the first LED 111 is not limited thereto. The second display panel 200 may be disposed on the part, and a light shielding tape may be disposed to shield light leaked from the first LED 111.

( Reference example )
FIG. 4 is a schematic cross-sectional view of the electro-optical device 1 for explaining a modification of the above embodiment. 4, parts having the same functions as those in FIG. 2 are denoted by the same reference numerals, and description of common parts is omitted. In the modification, a cutout portion (hole) 301 having substantially the same shape as the light shielding tape 400 is formed at a position covering the head of the second LED 211 of the reflection sheet 300. The light shielding tape 400 is disposed in the cutout portion 301 of the reflection sheet 300 and the light shielding tape 400 is attached to the heads of the first light guide plate 112 and the second LED 211. The reflection sheet 300 and the light shielding tape 400 are substantially flush with each other.

According to the modified example, at a position covering the head of the second LED 211 of the reflection sheet 300,
Since a cutout portion (hole) 301 having substantially the same shape as the light shielding tape 400 is formed and the light shielding tape 400 is disposed in the cutout portion 301, the reflection sheet 300 and the light shielding tape 400 may be substantially flush with each other. In addition, the electro-optical device can be made thinner.

  The electro-optical device according to the present invention can be used for transmissive, reflective, and transflective electro-optical devices. The electro-optical device according to the present invention is applied to a passive matrix type electro-optical device or an active matrix type electro-optical device (for example, an electro-optical panel including a TFT (thin film transistor) or a TFD (thin film diode) as a switching element). Can be used. Further, the electro-optical device according to the present invention is not limited to a liquid crystal display device, but is an organic electroluminescence device, an inorganic electroluminescence device, a plasma display device, an electrophoretic display device, an electron emission display device (Field Emission Display and Surface-Conduction Electron). -Emitter Display etc.), LED (Light Emitting Diode) display devices, etc., and can be used for various electro-optical devices that can control the display state for each of a plurality of pixels.

  An electronic device equipped with the electro-optical device according to the present invention includes a mobile phone, a portable information device called PDA (Personal Digital Assistants), a portable personal computer, a personal computer, a workstation, a digital still camera, an in-vehicle monitor, a digital Widely used in electronic devices such as video cameras, LCD TVs, viewfinder type, monitor direct view type video tape recorders, car navigation devices, pagers, electronic notebooks, calculators, word processors, workstations, video phones, and POS terminals. Can do.

FIG. 2 is a perspective view illustrating a schematic overall configuration of an electronic apparatus according to the present embodiment. FIG. 2 is a perspective view illustrating a schematic overall configuration of an electronic apparatus according to the present embodiment. 1 is a schematic cross-sectional view of an electro-optical device according to an embodiment. The top view for demonstrating a light shielding tape. Sectional view showing a reference example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic device, 10 Electro-optical apparatus, 100 1st display panel (main display panel), 101 1st upper polarizing plate, 102 1st lower polarizing plate, 110 1st illumination means, 111 1st LED, 112 First light guide plate, 113 First diffusion sheet, 114 First prism sheet, 120 FPC, 200 Second display panel (sub display panel), 201 Second upper polarizing plate, 202 Second upper polarization Plate, 210 second illumination means, 211 second LED, 212 second light guide plate, 213 second diffusion sheet, 214 second prism sheet, 220 FPC, 300 reflection tape, 400 light shielding tape, 401 protrusion , 500 Body

Claims (6)

In an electro-optical device with display panels on both sides,
First and second illumination means including first and second light sources and emitting illumination light to the first and second surface sides, respectively.
A reflecting member provided between the first illuminating means and the second illuminating means and having reflecting surfaces formed on both sides;
A normally white first display panel which is provided on the first surface side with the first illumination means as a backlight and capable of displaying an image;
A second display panel that is provided on the second surface side as the backlight with the second illumination means as a backlight, has a smaller outer shape than the first panel, and can display an image;
With
The first illumination means includes a first light guide plate that guides illumination light emitted from the first light source to the first surface side, and the first light source is an end surface of the first light guide plate. Arranged opposite to
The second illumination means includes a second light guide plate that guides the illumination light emitted from the second light source to the second surface side, and the second light source is an end surface of the second light guide plate. Arranged opposite to
The first light source is an area that does not overlap an area for displaying an image of the second display panel, and is disposed in an area that overlaps the first display panel.
The second light source is disposed in a region displaying an image of the first display panel and a region overlapping the second display panel;
A light shielding member is disposed between the second light source and the reflecting member,
An electro-optical device that prevents illumination light emitted from the second light source by the reflection sheet and the light shielding member from leaking to the first display panel side. The light shielding member is disposed between the head of the second light source and the reflecting member, and shields light from leaking from the head of the second light source to the first display panel. The electro-optical device according to claim 1 .   The electro-optical device according to claim 1, wherein the light shielding member is a light shielding tape.   The electro-optical device according to claim 1, wherein the first and second light sources are LEDs.   5. The electro-optical device according to claim 1, wherein the light shielding member has a silver color on the first surface side and a white color on the second surface side. 6.   An electronic apparatus comprising the electro-optical device according to claim 1.

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