JP4702334B2 - Electro-optical device and electronic apparatus including the electro-optical device - Google Patents

Description

The present invention relates to an electro-optical device used in, for example, a cellular phone, and more particularly to an electro-optical device having optical panels on both front and back surfaces and an electronic apparatus including the electro-optical device.

In recent years, electro-optical devices such as liquid crystal display devices have been widely used as display units in electronic devices such as mobile phones, portable computers, and video cameras. As this electro-optical device, in particular, a mobile phone or a PDA (Personal Digital Assistant)
) And the like, in which two liquid crystal devices are arranged back to back (see, for example, Patent Document 1 and Patent Document 2).
In such an electronic device, the first liquid crystal panel and the second liquid crystal panel are arranged at a predetermined interval, and light is sequentially guided between the first liquid crystal panel and the second liquid crystal panel from the first liquid crystal panel side. A member and a transflective plate are provided. A part of the light guided through the light guide member is reflected by the transflective plate and travels to the first liquid crystal panel, and the remaining light is transmitted by the transflective plate, and the second liquid crystal panel. Head for. In this way, image light is emitted from the display surface side of each liquid crystal panel.

By the way, when the first liquid crystal panel and the second liquid crystal panel are arranged to face each other with the transflective plate sandwiched between them as in the liquid crystal display devices described in Patent Document 1 and Patent Document 2, the liquid crystal displays of each other are displayed. It will affect the liquid crystal display on the opposite side as a shadow and cause display defects. As a double-sided display device that solves this problem, a device that sets the second liquid crystal panel to black display (LED is normally black) and shields transmitted light from the back surface has been proposed (see, for example, Patent Document 3). .

JP 2004-87409 A JP 2003-207801 A JP 2004-78047 A

Here, in the liquid crystal display devices described in Patent Document 1 and Patent Document 2, only the light of the light guide member is divided into both surfaces using a transflective plate. In the double-sided display device described in Patent Document 3, external light incident from the second liquid crystal panel side is shielded to the first,
When viewed from the liquid crystal panel side, the area where the second liquid crystal panel is disposed is prevented from being brightened. Therefore, in the technologies described in Patent Document 1 to Patent Document 3, depending on the environment,
When viewed from the first liquid crystal panel side, there arises a problem that the area of the second liquid crystal panel becomes dark.

  The present invention has been made to solve the above-described problem, and an electro-optical device that prevents a shadow of the second optical panel from appearing on the first optical panel with a simple configuration, and the electro-optical device. It is an object to provide an electronic device including

In order to achieve the above object, the present invention provides the following means.
The electro-optical device includes a first optical panel including a pair of substrates that sandwich the electro-optical material, and a pair of substrates that sandwich the electro-optical material, and is disposed so as to overlap the first optical panel in a plane. The second optical panel having a smaller planar dimension than the first optical panel, a light source that emits light, and the first optical panel and the first optical panel, and the first optical panel and the second optical panel. And a light guide member for allowing light emitted from the light source to enter each of the two optical panels, and a display area of the second optical panel on the second optical panel side of the light guide member. The light emitted from the light guide member is directed to light that is directed to a region other than the display region of the second optical panel and light that is reflected from a region other than the display region of the second optical panel. Comprising a light absorbing member having an opening for incident light to the display area of the panel, pre SL and a second optical panel side of the prism sheet and a diffusion sheet, a light-guiding member has an end surface opposed to the light source The light guide member has an inclined surface where the thickness of the light guide member decreases with distance from the light guide member, and the prism sheet and the diffusion sheet are disposed between the light guide member and the light absorbing member. The edge of the opening of the light absorbing member overlaps the edge of the prism sheet and the diffusion sheet at a position where it can be provided.

When the present inventor examined conventional problems, the intensity of light emitted from a region where the second optical panel is not disposed and a region where the second optical panel is disposed in the first liquid crystal panel. I found the problem that there was a difference. This is because the light emitted from the light guide member to the region where the second optical panel is not disposed is reflected, for example, inside the housing and then travels toward the first optical panel, so that the intensity of the light is the second optical The problem is that it is stronger than the light emitted from the area where the panel is arranged.

In the electro-optical device according to the present invention, the light absorbing member is provided on one end surface of the light guide member on the second optical panel side, so that when the light absorbing member is disposed in a portion other than the display area of the second optical panel, It becomes easy to align the absorbing member and the second optical panel.
In the electro-optical device according to the aspect of the invention, a light-shielding film is formed on a peripheral portion of the pair of substrates on the liquid crystal layer side of the second optical panel, and an edge of the opening of the light absorbing member is formed on the second optical panel. that is located in a region overlapping with the light-shielding film in the peripheral portion of the panel.

  In the electro-optical device according to the aspect of the invention, it is preferable that the light absorbing member is provided on the second optical panel side of the light guide member.

In addition, the electro-optical device according to the aspect of the invention has an opening for allowing the light emitted from the light guide member to enter the display area of the first optical panel on the first optical panel side of the light guide member. It is preferable that a light shielding member is provided.

Electro-optical device of the present invention includes a first optical panel side prism sheet and a diffusion sheet between said light blocking member and the light guide member, the edge of the opening of the light shielding member, wherein the first optical panel that located in the region overlapping the prism sheet and the edges of the diffusion sheet of use.
Electro-optical device of the present invention, between the light-absorbing member and the light guide member, to reflect part of the light from the light guide member side to the first optical science panel side, wherein the remainder of the light semitransparent reflective sheet that provided to transmit to the second optical science panel.
In the electro-optical device according to the aspect of the invention, it is preferable that the light absorbing member is a black resin film.
In the electro-optical device according to the present invention, since the light absorbing member is a black resin film, light can be sufficiently absorbed, and the entire device can be thinned.

In the electro-optical device according to the aspect of the invention, the opening formed in the light absorbing member and the display area of the second optical panel are rectangular, and the opening is four sides of the display area of the second optical panel. of Ru is arranged around the region.

Electronic device of the present invention, that provides the above-described electro-optical device as a display unit.
The electronic apparatus according to the present invention can provide an electronic apparatus including an electro-optical device that can display an image with high quality.

Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

First, a liquid crystal display device according to an embodiment of the electro-optical device of the present invention will be described with reference to FIGS.
Will be described with reference to FIG.
As shown in FIGS. 1 and 2, the liquid crystal display device 1 according to the present embodiment is provided in a housing 2, and includes a first liquid crystal panel 10 including a pair of substrates 11 and 12, and a pair of substrates 21 and 22. The second liquid crystal panel 20 is disposed so as to overlap the first liquid crystal panel 10 in a planar manner and has a smaller planar size than the first liquid crystal panel 10, and the first and second liquid crystal panels 10, 20. A lighting device 30 used as a common backlight and a light absorbing member 40 provided between the first liquid crystal panel 10 and the second liquid crystal panel 20 are provided.

As shown in FIG. 2, the first liquid crystal panel 10 includes a pair of rectangular substrates 11 and 12 that are provided to face each other with a cell gap therebetween with a sealing material 13 therebetween.
And a liquid crystal layer (electro-optical material) 14 sandwiched between the two, and an illumination device 30 is provided on the substrate 12 side. An exit-side polarizing plate 15 is provided on the outer surface 11 a of the substrate 11, and an incident-side polarizing plate 16 is provided on the outer surface 12 a of the substrate 12. Also, the substrate 12
A driver 4 for performing image display processing of each of the first and second liquid crystal panels 10 and 20 is mounted.

As shown in FIG. 2, the second liquid crystal panel 20 is similar to the first liquid crystal panel 10 in the sealing material 2.
A pair of rectangular substrates 2 in plan view provided facing each other with a cell gap therebetween via 3
1 and 22 and a liquid crystal layer (electro-optical material) 24 sandwiched between the substrates 21 and 22, and an illumination device 30 is provided on the substrate 22 side. Further, an exit-side polarizing plate 25 is provided on the outer surface 21 a of the substrate 21, and an incident-side polarizing plate 26 is provided on the outer surface 22 a of the substrate 22.

One substrate 21 has a plurality of scanning lines (not shown) in a matrix on the upper surface on the liquid crystal layer 24 side.
And a plurality of data lines (not shown) are formed, and a pixel electrode 42 is provided for each region surrounded by the scanning lines and the data lines. A TFT element 41 is provided at a position where the scanning line and the data line intersect, and each pixel electrode 42 is connected to the data line via the TFT element 41.
Accordingly, when a signal is applied to the scanning line and the data line, the TFT element 41 is turned on / off, and the signal is written to the pixel electrode 42. An alignment film 43 that has been subjected to a rubbing process is formed on the entire surface of the TFT element 41, the pixel electrode 42, and the like.

Further, on the lower surface of the substrate 22 on the liquid crystal layer 24 side, a peripheral light shielding film 51, a color filter 52,
An overcoat layer 53, a common electrode 54, and an alignment film 55 are laminated in this order. The common electrode 54 is a flat film formed of a light-transmitting conductive material such as ITO.
The peripheral light-shielding film 51 has a rectangular frame shape in plan view, is provided along the inner peripheral side of the sealing material 23, and defines an effective image display area A.
Further, the color filter 52 includes a light shielding portion 52a and colored portions 52R, 5 of red, green, and blue.
2G and 52B, and the light shielding part 52a is formed in a matrix so as to partition the colored parts 52R, 52G and 52B. The light shielding part 52a is made of, for example, a black photosensitive resin film.

The above-described substrates 11, 12, 21, and 22 are light transmissive substrates made of a transparent material such as glass. The alignment films 43 and 55 are made of polyimide, for example.
The first and second liquid crystal panels 10 and 20 are provided with an FPC board (Flexible Printed Circuit) 3 as shown in FIGS. The FPC board 3 is a flexible circuit board on which electronic components 5 and the like are mounted.

As shown in FIG. 1, the illumination device 30 is disposed between a light source 31 that emits light, the first liquid crystal panel 10, and the second liquid crystal panel 20, and the first liquid crystal panel 10 and the second liquid crystal panel. 2
And a light guide plate (light guide member) 32 for allowing the light emitted from the light source 31 to enter each of the zero.
The light source 31 is assumed to be composed of, for example, an LED (Light Emitting Diode). The light source 31 may be composed of something other than an LED. For example, the light source 31 may be composed of a semiconductor laser such as an organic electroluminescence element, an edge emitting semiconductor laser, or a surface emitting semiconductor laser. Moreover, you may comprise a light source with a cold cathode tube. As shown in FIG. 2, the light source 31 is mounted and mounted on a substrate 31a.

The light guide plate 32 is a plate made of a light transmissive material such as acrylic resin, and a diffusion sheet 34 and a first prism sheet 35 are provided on one surface (other surface) 32a on which the first liquid crystal panel 10 is disposed.
And the 2nd prism sheet 36 is provided in order.
The diffusion sheet 34 is a plate-shaped sheet member that diffuses light emitted from the light guide plate 32.
As the diffusion sheet 34, an acrylic sheet in which a diffusing agent is dispersed can be used. With this diffusion sheet 34, the surface brightness of the light emitted from the light guide plate 32 can be made uniform, and the grooves of the first prism sheet 35 and the second prism sheet 36 and reflections (unevenness of brightness) can be prevented. It has become.
Further, the first prism sheet 35 and the second prism sheet 36 have a prism surface on one surface side (first liquid crystal panel 10 side) made of a transparent acrylic resin or the like. Various irregularities (not shown) are formed.

Further, the transflective sheet 3 is provided on the other surface 32b of the light guide plate 32 on the second liquid crystal panel 20 side.
3 is provided. The transflective sheet 33 is made of, for example, a transparent resin film,
A part of the light guided through the light guide plate 32 is reflected toward the first liquid crystal panel 10 and the remaining light is transmitted toward the second liquid crystal panel 20.

As shown in FIG. 5, the light absorbing member 40 has an opening 4 having a size equivalent to that of the second liquid crystal panel 20.
0a is formed. And the light absorption member 40 is distribute | arranged between the 1st liquid crystal panel 10 and the 2nd liquid crystal panel 20, as shown in FIG. Specifically, the light absorbing member 40 is provided on the other surface 32b side of the light guide plate 32, and one end portion of the light absorbing member 40 holds the second liquid crystal panel 20, for example, a frame 6 made of white resin. It is fixed to. Further, the light absorbing member 40 is provided outside the display area of the second liquid crystal panel 20. That is, the light absorbing member 40 is provided in the display area of the second liquid crystal panel 20 so that the opening 40a is positioned as shown in FIG.

Specifically, in the light absorbing member 40, the edge of the opening 40a is located in a peripheral light shielding film (light shielding region) 51 in the peripheral portion of the second liquid crystal panel 20, as shown in FIG. The length L from the edge of the opening 40a to the end face 51a on the color filter 52 side of the peripheral light shielding film 51 is equal to or greater than the positional deviation between the second liquid crystal panel 20 and the light absorbing member 40 when the liquid crystal display device 1 is assembled. It only has to be length. Thereby, it is possible to prevent the light-absorbing member 40 from shielding the effective display area A. In the present embodiment, the length L is 0.5 mm .

In addition, the light absorbing member 40 is emitted from the other surface 32b of the light guide plate 32, and is reflected by the light toward the outside of the display area of the second liquid crystal panel 20 and the inside of the housing 2, the frame 6, or the like. To the first liquid crystal panel 10 is absorbed. That is, the first
In the liquid crystal panel 10, the light emitted from the region where the second liquid crystal panel 20 is disposed is transmitted through the opening 40 a and the light emitted from the region where the second liquid crystal panel 20 is not disposed is absorbed. Is possible.

Furthermore, in this embodiment, the light absorption member 40 is a resin film and is made of a black polyethylene terephthalate (PET) material. In addition, although the polyethylene terephthalate (PET) was used as the light absorption member 40, it is not restricted to this, Polyethylene naphthalate (PEN), Triacetyl cellulose (TAC), Polyarylate, Polyimide, Polyether, Polycarbonate, Polysulfone, Various resin films made of polyethersulfone, cellophane, polyamide, polyethylene, polypropylene, polyvinyl alcohol and the like can also be used.
Further, between the transflective sheet 33 and the light absorbing member 40, the above-described diffusion sheet 34,
A diffusion sheet 41, a first prism sheet 42, and a second prism sheet 43, which are the same as the first prism sheet 35 and the second prism sheet 36, are provided in this order from the transflective sheet 33 side.

The light shielding member 45 is disposed between the incident-side polarizing plate 16 on the one surface 32 a side of the light guide plate 32 and the second prism sheet 36, and the light emitted from the light guide plate 32 is directed to the first liquid crystal panel 10. It has an opening 45a for incidence. The opening 45a is formed by the diffusion sheet 34, the first
The prism sheet 35 and the second prism sheet 36 are large enough to cover the vicinity of the outer edge and the end face. This prevents light from entering the non-display area at the peripheral edge of the first liquid crystal panel 10 from the light emitted from the light guide plate 32.

Next, the operation of the liquid crystal display device 1 of the present embodiment having the above configuration will be described below.
First, the light emitted from the light source 31 enters the light guide plate 32 and guides the inside of the light guide plate 32. A part of the light guided inside the light guide plate 32 is reflected to the first liquid crystal panel 10 side by the transflective sheet 33 provided on the other surface 32b of the light guide plate 32, and the remaining light is ,
The light is transmitted to the second liquid crystal panel 20 side. At this time, out of the light directed to the first liquid crystal panel 10, the light emitted from other than the display area of the second liquid crystal panel 20 and the inside of the housing 2, the frame 6, and the like are reflected from the second liquid crystal panel 20 side to the first. Light traveling toward the liquid crystal panel 10 is absorbed by the light absorbing member 40. Thereby, in the area | region of the 1st liquid crystal panel 10 seen from the 1st liquid crystal panel 10 side, the light inject | emitted from the area | region where the 2nd liquid crystal panel 20 is distribute | arranged, and the area | region where the 2nd liquid crystal panel 20 is arrange | positioned Is substantially uniform.

According to the liquid crystal display device 1 according to the present embodiment, since the light absorbing member 40 is provided, it is possible to suppress display luminance unevenness as viewed from the first liquid crystal panel 10 side. Therefore, the shadow of the second liquid crystal panel 20 does not occur on the first liquid crystal panel 10.

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.
For example, as shown in FIG. 2, the light absorbing member 40 is disposed between the first liquid crystal panel 10 and the second liquid crystal panel 20 and is provided on the other surface 32 b side of the light guide plate 32. However, the present invention is not limited to this, and the light guide plate 32 may be provided on the one surface 32a side.

1 is an exploded view showing an electro-optical device according to a first embodiment of the invention. FIG. FIG. 2 is a cross-sectional view of a main part showing the electro-optical device of FIG. 1. FIG. 2 is a top view showing the electro-optical device of FIG. 1. FIG. 2 is a bottom view showing the electro-optical device of FIG. 1. FIG. 2 is a perspective view illustrating a light absorbing member of the electro-optical device in FIG. 1. FIG. 2 is an enlarged cross-sectional view of a main part showing a size of a light absorbing member of the electro-optical device in FIG. 1. FIG. 11 is a perspective view illustrating an embodiment of an electronic apparatus according to the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device (electro-optical device), 10 ... 1st liquid crystal panel, 14 ... Liquid crystal layer (electro-optical material), 20 ... 2nd liquid crystal panel, 14 ... Liquid crystal layer (electro-optical material), 30 ... Illumination device, 31
... light source, 32 ... light guide plate (light guide member), 32a ... one surface of the light guide plate, 32b ... the other surface of the light guide plate, 45 ... light shielding member, 45a ... opening of the light shielding member.

Claims (8)

A first optical panel comprising a pair of substrates sandwiching an electro-optic material;
A second optical panel comprising a pair of substrates sandwiching an electro-optical material and disposed so as to overlap the first optical panel in a planar manner, and having a smaller planar dimension than the first optical panel;
A light source that emits light and a light that is arranged between the first optical panel and the second optical panel, and the light emitted from the light source is incident on each of the first optical panel and the second optical panel. An illumination device having a light guide member
Light that is provided outside the display area of the second optical panel on the second optical panel side of the light guide member, and that travels outside the display area of the second optical panel among the light emitted from the light guide member; A light absorbing member that absorbs light reflected outside the display area of the second optical panel and has an opening for allowing light to enter the display area of the second optical panel;
Comprising a prism sheet and a diffusion sheet before Symbol second optical panel side, and
The light guide member has an inclined surface in which the thickness of the light guide member decreases as the distance from the end surface facing the light source decreases.
The edge of the opening of the light absorbing member is positioned at a position where the prism sheet and the diffusion sheet can be disposed between the light guiding member and the light absorbing member. An electro-optical device overlapping the edges of the prism sheet and the diffusion sheet. A light-shielding film is formed in a peripheral portion on the liquid crystal layer side of the pair of substrates of the second optical panel;
The optical edge of the opening of the absorbing member, the electro-optical device according to 請 Motomeko 1 that is located in a region overlapping with the light-shielding film in the peripheral portion of the second optical panel. Said first optical panel side of the light guide member, 請 Motomeko shielding member that provided with an opening for applying light emitted from the light guide member in the display region of the first optical panel The electro-optical device according to claim 1. A prism sheet and a diffusion sheet on the first optical panel side are provided between the light guide member and the light shielding member, and an edge of the opening of the light shielding member is formed of the prism sheet and the diffusion sheet for the first optical panel. the electro-optical device according to 請 Motomeko 3 that is located in an area overlapping the edges. Between the light-absorbing member and the light guide member, said to reflect a part of light to the first optical science panel side from the light guide member side, transmits the remaining light to the second optical science panel side the electro-optical device according to any one of claims 4 請 Motomeko 1 that have semitransparent reflective sheet is provided to. The light absorbing member, the electro-optical device according to any one of claims 5 to 請 Motomeko 1 Ru resin film der black. Display area of the opening portion and the second optical panel is formed on the light-absorbing member is rectangular, billed to the opening Ru arranged in the region around the four sides of the display area of the second optical panel the electro-optical device according to any one of claims 6 to claim 1. Electrooptical have that electronic equipment includes a display unit according to any one of claims 1 to 7.

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