JP2002098959A - Liquid crystal display module and electronic device using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the thickness of a liquid crystal display module while maintaining the display quality. SOLUTION: A liquid crystal display panel in which liquid crystal is sealed between a pair of substrates, and a polarizing plate is attached to a part of a surface of the pair of substrates opposite to the liquid crystal; In a liquid crystal display module provided on one surface side and guiding a light incident on a side end surface to the liquid crystal display panel side, and a light source opposed to the side end surface, the liquid crystal display panel in the light guide plate The side surface has a configuration including a protruding surface and a non-protruding surface. The protruding surface is a surface protruding toward the liquid crystal display panel and adjacent to the side end surface, and supports a substrate of the liquid crystal display panel facing the light guide plate. On the other hand, the non-projecting surface is lower than the projecting surface and supports the polarizing plate facing the light guide plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a liquid crystal display module and an electronic apparatus using the same.

[0002]

2. Description of the Related Art As is well known, a liquid crystal display panel is widely used for a display device of a portable electronic device such as a portable telephone. However, since the liquid crystal itself is a non-light emitting element, it can be visually recognized in a dark place. In general, a backlight unit is provided on the back surface of the liquid crystal display panel in order to ensure performance.
Here, the backlight unit includes a light source, and a light guide plate that receives light from the light source on a side surface and guides the light to a substrate surface of the liquid crystal display panel.

[0003]

However, in a display device used for such a portable electronic device, the demand for a thinner device is extremely severe. In order to meet this demand, it is necessary to reduce the thickness of not only the liquid crystal display panel but also the backlight unit.

Here, in order to realize a thin backlight unit, it is desirable that the light guide plate is also thin. However, when the light guide plate is made thin, the area of the side surface receiving the light from the light source becomes small, so that the amount of light incident on the light guide plate becomes small. As a result, there may be a problem that the liquid crystal display panel is not irradiated with sufficient light and the display becomes dark.

The present invention has been made in view of the circumstances described above, and provides a liquid crystal display module that can efficiently use light from a light source while satisfying a demand for thinning, and an electronic device using the same. The purpose is to do.

[0006]

According to the present invention, a liquid crystal is sealed between a pair of substrates, and a polarizing plate is provided on a part of a surface of the pair of substrates opposite to the liquid crystal. A light guide plate disposed on one surface side of the liquid crystal display panel and guiding light incident on a side end surface to the liquid crystal display panel side, and a light source facing the side end surface Wherein the surface of the light guide plate on the liquid crystal display panel side includes a protruding surface and a non-protruding surface. That is, the protruding surface is a surface that protrudes toward the liquid crystal display panel and is adjacent to the side end surface, and is a surface that supports the substrate facing the light guide plate in the liquid crystal display panel. This is a surface that is lower than the protruding surface and supports the polarizing plate facing the light guide plate.

By forming the protruding surface on the light guide plate as described above,
Since the area of the side end surface (that is, the area of the region irradiated with light from the light source) can be increased, the amount of light incident on the light guide plate can be increased as compared with the case where no protruding surface is provided. Thus, the display by the liquid crystal display module can be made brighter.

On the other hand, the non-projecting surface of the light guide plate supports the polarizing plate on the rear side of the liquid crystal display panel, and the projecting surface supports the substrate on the rear side of the liquid crystal display panel. In other words, to fit into the step formed by the protruding surface and the non-protruding surface in the light guide plate,
Since the liquid crystal display panel is provided, the thickness of the liquid crystal display module itself is increased in spite of the configuration in which the light guide plate can receive sufficient light as described above. There is no such thing as. As described above, according to the liquid crystal display module of the present invention, it is possible to effectively meet the demands for both improvement in display quality and reduction in thickness.

Here, in the liquid crystal display module, a plate-like member is attached to the non-projecting surface of the light guide plate, and a polarizing plate facing the light guide plate comes in contact with the plate-like member. Is also good. As the plate-like member, for example, it is conceivable to use at least one of a diffusion plate for diffusing light emitted from the light guide plate and a light collecting plate for condensing light emitted from the light guide plate. In this case, the light from the light source can be further effectively used by the action of the diffusion plate and the light collector.

In the liquid crystal display module, it is preferable that a notch corresponding to the outer shape of the light source is provided on the side end face of the light guide plate. With this configuration, the light source can be disposed at a position closer to the light guide plate by the amount of the cutout, and the size of the liquid crystal display module can be reduced. Further, the area of the surface of the cutout that receives light from the light source can be increased, so that the light from the light source can be used more efficiently.

On the other hand, a case accommodating the light guide plate, the case having a support surface having substantially the same height as the protruding surface of the accommodated light guide plate is further provided, and a substrate facing the light guide plate is provided. A configuration supported by both the protruding surface and the support surface is also desirable. With this configuration, since the substrate on the back side of the liquid crystal display panel is supported not only by the protruding surface of the light guide plate but also by the support surface of the case, the liquid crystal display panel is more reliably supported. Become.

Further, when such a configuration is adopted, the substrate facing the light guide plate is fixed to both the projecting surface and the supporting surface by a double-sided tape adhered to the projecting surface and the supporting surface. It may be. In this case, the liquid crystal display module is fixed to the protruding surface of the light guide plate and the support surface of the case by the double-sided tape, so that a configuration resistant to external impact can be realized. In the case where a double-sided tape is used as described above, it is preferable that an angle between a surface from the non-projecting surface to the projecting surface and the non-projecting surface in the light guide plate is an obtuse angle. By forming the light guide plate in such a shape, there is an advantage that the work of attaching the double-sided tape to the step portion (slope portion) from the non-projecting surface to the projecting surface can be easily performed.

According to another aspect of the invention, there is provided an electronic apparatus including the above-described liquid crystal display module. According to such an electronic device, it is possible to simultaneously satisfy the requirements for both improvement in display quality and reduction in thickness.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. Such an 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.

FIG. 1 is an exploded perspective view of a liquid crystal display module according to an embodiment of the present invention. As shown in FIG. 1, the liquid crystal display module includes a case 10, a light guide plate 20, a liquid crystal display panel 40, a diffusion plate 30, a light collector 31, and both surfaces interposed between the liquid crystal display panel 40 and the light guide plate 20. It is configured to include the tape 32. In FIG. 1, the polarizing plate 46 is a component of the liquid crystal display panel 40, but is separated from the liquid crystal display panel 46 for convenience of explanation. Also, actually, the liquid crystal display panel 40
A flexible printed circuit board on which an IC chip or the like for driving the LCD is mounted is moved from the liquid crystal display panel 40 to the case 10.
Is formed so as to reach the back side (the side opposite to the light guide plate 20), but since it is not directly related to the present invention, its description and illustration are omitted.

The case 10 is made of plastic and has a role of accommodating the light guide plate 20 and supporting the liquid crystal display panel 40. The case 10 includes a rectangular bottom portion 11 and three side portions 12a, 12b, and 12c formed along each side of the bottom portion 11. Furthermore, the side portion 1 along the short side of the bottom portion 11
Of the 2b, a plurality of white LEDs (Light Emitting Diodes) 13 are arranged on the surface on the side where the light guide plate 20 is accommodated. Each white LED 13 functions as a light source for irradiating light to the side surface of the light guide plate 20 housed in the case 10. In the following, the white LE of the light guide plate 20 is used.
The side surface facing D13, that is, the side surface on which light from the white LED 13 is incident is referred to as "light incident surface".

The light guide plate 20 is a plate-like member for guiding light incident on the light incident surface from the white LED 13 to the liquid crystal display panel 40 side. Here, FIG. 2 is a cross-sectional view showing the configuration in the vicinity of the white LED 13 when the assembled liquid crystal display module is viewed from the line AA ′ shown in FIG. As shown in the figure, the light guide plate 20 has one surface
The case 10 is housed in a region surrounded by the side surfaces 12 a to 12 c of the case 10 in a state of being in contact with the bottom surface 11. Specifically, side portions 12a and 12
c is provided with a hole (not shown), and the light guide plate 10
The protrusion (not shown) provided on the side surface is housed in the case 10 in a state of being engaged with each of the holes.

As shown in FIG. 1 and FIG.
Includes a protruding surface 21 protruding toward the liquid crystal display panel 40 and a non-protruding surface 22 lower than the protruding surface 21.
Are adjacent (intersecting) with the light incident surface. In other words, of the edges of the light guide plate 20, the edge near the white LED 13 when housed in the case 10 has a shape protruding toward the liquid crystal display panel 40. According to such a configuration, the area of the light incident surface of the light guide plate 20 is determined by the area of the cross section of the non-projecting surface 22 parallel to the light incident surface (that is, the cross sectional area of the light guide plate 20 at a position sufficiently distant from the white LED 13). Can also be wider.
Further, as shown in FIG. 2, in the present embodiment, the height of the protruding surface 21 of the light guide plate 20 and the top surface of the side surface portion 12b of the case 10 (corresponding to the “support surface” in the claims). And the height are almost the same. In the following, a surface inclined from the protruding surface 21 to the non-protruding surface 22 is referred to as a “slope 23”.

FIG. 3A is a perspective view illustrating the shape of the light guide plate 20 when viewed from the side surface 12b (white LED 13 side). FIG. 3B is a perspective view of the light guide plate 20. FIG. 3 is a plan view illustrating the positional relationship between the light guide plate 20 and the white LED 13 when viewed from the liquid crystal display panel 40 side. As shown in these drawings, a portion of the light incident surface of the light guide plate 20 facing each white LED 13 is provided with the white LED 1.
A notch 24 corresponding to the outer shape of No. 3 is formed.

On the other hand, as shown in FIGS. 1 and 2, the non-projecting surface 22 of the light guide plate 20 has a diffusion plate 3 for uniformly diffusing light emitted from the light guide plate 20 to the liquid crystal display panel 40.
0 and a light collector (prism sheet) 31 for improving the light collection efficiency are adhered.

Next, the double-sided tape 3 shown in FIGS.
2 is for fixing the liquid crystal display panel 40 to one side of the light guide plate 20. The double-sided tape 32 is formed by applying an adhesive to both surfaces of a thin film having a light-shielding property,
The display area of the liquid crystal display panel 40 (more precisely, the polarizing plate 4
An opening 32a is provided corresponding to (6). Light guide plate 20
The light emitted from the light source and passing through the diffusion plate 30 and the light collector 31 reaches the display area of the liquid crystal display panel 40 through the opening 32 a of the double-sided tape 32. However, light emitted from the light guide plate 20 to reach a region outside the display region of the liquid crystal display panel 40 is blocked by the double-sided tape 32.

The double-sided tape 32 extends from the non-projecting surface 22 of the light guide plate 20 to the projecting surface 21 via the inclined surface 23, and further has the top surface of the side surface portion 12 b of the case 10 having substantially the same height as the projecting surface 21. It has a shape that leads to Here, as shown in FIG. 1, the angle θ between the inclined surface 23 and the non-projecting surface 21 in the light guide plate 20 is an obtuse angle (15 in the present embodiment).
0 °). With this configuration, compared to the case where the angle θ is set to 90 ° or less, the non-projecting surface 22 of the light guide plate 20 can be used.
There is an advantage that the work of sticking along the step from the to the protruding surface 21 can be easily performed.

On the other hand, as shown in FIG. 2, the liquid crystal display panel 40 has a pair of substrates 41 and 42 bonded together via a sealing material 43 and a liquid crystal 44 sealed between the two substrates.
And polarizers 45 and 46 attached so as to cover regions other than the edges of the outer surfaces (opposite to the liquid crystal 44) of both substrates. An electrode for driving the liquid crystal 44 and an alignment film subjected to a rubbing process for defining the alignment direction of the liquid crystal are formed on the inner surfaces of both substrates, but are not directly related to the present invention. Therefore, illustration and detailed description thereof are omitted.

As shown in FIGS. 1 and 2, the liquid crystal display panel 40 is fixed to one side of the light guide plate 20 via a double-sided tape 32. The details are as follows.
First, as shown in FIG. 1 and FIG.
The polarizing plate 46 located on the back side (that is, the side opposite to the observation side) passes through the opening 32 a of the double-sided tape 32, and its surface comes into contact with the surface of the light collector 31. . Furthermore, the portion of the substrate 42 of the liquid crystal display panel 40 that is not covered by the polarizing plate 46 is the protruding surface 21 of the light guide plate 20 and the side surface 12 of the case 10.
b Contact the double-sided tape 32 stuck over both top surfaces. In other words, in the liquid crystal display panel 40, the polarizing plate 46 on the back side is supported by the non-projecting surface 22 of the light guide plate 20, and the substrate 42 on the back side is the projecting surface 21 on the light guide plate 20 and the side surface on the case 10. It is supported by the top surface of the portion 12b.

As described above, according to the present embodiment, the portion of the surface of the light guide plate 20 on the side of the liquid crystal display panel 40 which is close to the light incident surface is formed as a protruding surface protruding toward the liquid crystal display panel 40. The area of the light incident surface irradiated with the light from the white LED 13 is relatively large. Therefore, as compared with the case where the protruding surface 21 is not provided, the amount of incident light from the white LED 13 to the light guide plate 20 can be increased, and the display by the liquid crystal display module can be brightened.

On the other hand, the thickness of the non-projecting surface 22 of the light guide plate 20 can be made relatively thin, and the polarization plate 4
The liquid crystal display panel 40 is disposed so that the light guide plate 6 fits into a step formed by the protruding surface 21 and the non-protruding surface 22. Despite adopting a configuration that allows the liquid crystal display module to be incident on the liquid crystal display module, the thickness of the liquid crystal display module itself does not increase. As described above, according to the present embodiment, the display quality of the liquid crystal display module can be improved while responding to the demand for thinning.

Further, in this embodiment, the polarizing plate 4
6 is supported not only by the surface of the non-projecting surface 21 of the light guide plate 20, but also by the projecting surface 21 of the light guide plate 20 and the top surface of the side surface portion 12 b of the case 10. Therefore, the liquid crystal display panel 40 can be reliably supported.

In the present embodiment, the light guide plate 20
The light incident surface is provided with a notch 24 corresponding to the outer shape of each white LED 13. By doing so, each white LED 13 can be arranged at a position close to the light guide plate 20, so that the size of the liquid crystal display module can be reduced. Further, a white LED is provided on the surface of the notch 24.
Since the area receiving the light from the light source 13 can be increased, the amount of light incident on the light guide plate 20 can be increased as compared with the case where the notch 24 is not provided, and a brighter display can be realized. .

In the embodiment, the liquid crystal display panel which performs the transmissive display is exemplified. However, in the present invention, the transmissive display and external light such as natural light or room illumination light are made incident from the observation side, and this light is displayed. The present invention can be applied to a so-called transflective liquid crystal display panel, which can switch between a reflective display and a reflective display that performs display by reflecting light.

Next, electronic equipment to which the liquid crystal display module according to the above-described embodiment is applied will be described. FIG.
FIG. 2 is a perspective view illustrating a configuration of a mobile phone as an example of the electronic apparatus. In the figure, a mobile phone 1300 includes the above-described liquid crystal display panel 100, in addition to a plurality of operation buttons 1302, an earpiece 1304, and a mouthpiece 1306. As described above, when the liquid crystal display panel according to the embodiment is used as a display device, it is possible to simultaneously improve display quality and reduce the thickness of a mobile phone.

In addition, other electronic devices include a liquid crystal television, a notebook personal computer, a viewfinder type / monitor direct-view type video tape recorder,
Car navigation devices, pagers, electronic organizers, calculators,
Word processors, workstations, video phones,
Examples include a POS terminal, a digital still camera, and a device equipped with a touch panel. Needless to say, the liquid crystal display module according to the embodiment can be applied to these various electronic devices.

[0032]

As described above, according to the present invention,
It is possible to improve both the display quality and the thickness of the liquid crystal display module.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view illustrating the configuration of a liquid crystal display module according to an embodiment of the present invention.

FIG. 2 shows the same liquid crystal display module as AA ′ shown in FIG.
FIG. 3 is a cross-sectional view illustrating a configuration near a white LED when viewed from a line.

FIG. 3A is a perspective view illustrating a configuration of the light guide plate viewed from a white LED side, and FIG. 3B is a perspective view illustrating the light guide plate and a white LED when the light guide plate is viewed from a liquid crystal display panel side.
It is a top view which illustrates the positional relationship with respect to.

FIG. 4 is a perspective view illustrating the configuration of a mobile phone as an example of an electronic device using a liquid crystal display module.

[Explanation of symbols]

10 Case, 11 Bottom part, 12a, 12b, 1
2c ... side part, 13 ... white LED (light source), 20 ...
... Light guide plate, 21 ... Projecting surface, 22 ... Non-projecting surface, 23 ...
... Slope, 24 ... Notch, 30 ... Diffusion plate, 31 ... Condenser, 32 ... Double-sided tape, 32a ... Opening, 40 ...
... Liquid crystal display panel, 41 ... substrate, 43 ... sealing material,
44 ... liquid crystal, 45, 46 ... polarizing plate.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H038 AA52 AA55 BA06 2H089 HA40 JA10 QA11 TA15 TA18 TA20 2H091 FA08X FA08Z FA16Z FA21Z FA23Z FA41Z LA11 5G435 AA00 AA18 BB12 BB15 EE04 EE13 EE27 FF00 FF07 FF07 FF07 FF07 FF07 FF07 FF07 FF07 FF07 FF07 FF07 FF07 FF05 FF07 FF07 FF07 FF07 FF07 FF07 LL12 LL14 LL17

Claims (8)

[Claims] A liquid crystal display panel having a liquid crystal sealed between a pair of substrates and a polarizing plate attached to a part of a surface of the pair of substrates opposite to the liquid crystal; and the liquid crystal display panel. A light guide plate disposed on one side of the light guide plate and guiding light incident on the side end surface to the liquid crystal display panel side; and a light source opposed to the side end surface. The panel side surface is a protruding surface that protrudes toward the liquid crystal display panel side and is adjacent to the side end surface, the protruding surface supporting the substrate facing the light guide plate in the liquid crystal display panel, A liquid crystal display module comprising: a low non-projecting surface; and a non-projecting surface for supporting the polarizing plate facing the light guide plate. 2. The light guide plate according to claim 1, wherein a plate member is attached to the non-projecting surface of the light guide plate, and a polarizing plate facing the light guide plate abuts on the plate member. LCD module. 3. The plate-shaped member is at least one of a diffusion plate for diffusing light emitted from the light guide plate and a light collecting plate for condensing light emitted from the light guide plate. 3. The liquid crystal display module according to 2. 4. The liquid crystal display module according to claim 1, wherein the side end surface of the light guide plate has a cutout corresponding to an outer shape of the light source. 5. A case for accommodating the light guide plate,
The light guide plate further includes a case having a support surface having substantially the same height as the protruding surface of the light guide plate, wherein the substrate facing the light guide plate is supported by both the protruding surface and the support surface. Claim 1.
5. The liquid crystal display module according to any one of items 4 to 4. 6. The substrate facing the light guide plate is fixed to both the projecting surface and the supporting surface by a double-sided tape attached to the projecting surface and the supporting surface. A liquid crystal display module according to item 1. 7. The liquid crystal display module according to claim 6, wherein the light guide plate has an obtuse angle between the surface extending from the non-projecting surface to the projecting surface and the non-projecting surface. 8. An electronic apparatus comprising the liquid crystal display module according to claim 1.