JP2003202423A - Light guide plate and liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light guide plate and a liquid crystal display which can be made lightweight, small-sized, and thin by decreasing the number of components. <P>SOLUTION: The liquid crystal display 1 comprises the light guide plate 2, a reflection type liquid crystal display panel 4 which is arranged facing a reflection pattern 3 for a front light on the light guide plate 2, a transmission type or half-transmission type liquid crystal panel 6 which is arranged facing a reflection pattern 5 for a back light on the light guide plate 2, and a light source 7 which emits light 8 to the light guide plate 2. The light guide plate 2 is made of a translucent material and has a light emission surface 2a as one surface end an opposite surface 2b as the other surface facing the light emission surface 2a. On the opposite surface 2b, the reflection pattern 3 for the front light and reflection pattern 5 for the back light are provided which can reflect light and are different in reflection pattern. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide plate and a liquid crystal display device, and more particularly to a light guide plate and a liquid crystal display device suitable for a device having a display section on each of a front surface side and a back surface side.

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices have been used in the display section of various devices. Among such devices, there is a device in which a display section is provided on each of the front surface side and the back surface side, and for example, a mobile phone is given.

Some mobile phones are of the foldable type, and the foldable mobile phone is used in an open state at the time of use, but the portability is improved by keeping it in the closed state at the time of carrying. Some of the folding type mobile phones include a small window display unit on the front side (outside) of the mobile phone so that various information can be obtained even when the mobile phone is closed. This small window display section displays the name and telephone number of the other party as information when receiving a call, and the date and time as information when waiting.

On the other hand, the back side of the mobile phone is provided with an original display section which is seen when the mobile phone is opened. Each display unit is generally composed of a liquid crystal display device including a liquid crystal display panel. In this way, in order to provide the display unit on each of the front surface side and the back surface side of the mobile phone, in the mobile phone, a light guide plate for emitting light to the liquid crystal display panel of the small window display unit and its light source,
A light guide plate that emits light and its light source are separately provided on the original liquid crystal display panel of the display unit.

[0005]

Here, it is desired that the mobile phone be lightweight, small and thin. However, when the small window display unit is provided on the front surface side of the mobile phone in the closed state as described above, the light guide plate for emitting light to the liquid crystal display panel of the small window display unit and the light source thereof are required.

Therefore, in addition to the light guide plate and its light source for emitting light to the original liquid crystal display panel of the display unit, another set of light guide plate and its light source are required, which makes the mobile phone lighter and smaller. However, it has been an obstacle to further thinning.

There are various possible uses of the liquid crystal display device having display portions on both the front surface side and the back surface side in addition to the mobile phone. However, the liquid crystal display device is lightweight, small, and thin regardless of the application. Is preferred.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to reduce the number of parts in an apparatus having display portions on both the front surface side and the back surface side.
An object of the present invention is to provide a light guide plate and a liquid crystal display device that can reduce the weight, size, and thickness of the device.

[0009]

The light guide plate according to the present invention comprises:
As described in claim 1, in a light guide plate which is made of a translucent material and has one surface as a light emitting surface and the other surface facing the light emitting surface as a facing surface, light reflecting on the facing surface. And a reflection pattern for a front light and a reflection pattern for a back light which are different in reflection pattern from each other are provided. Thereby, light can be emitted in two directions with one light guide plate. Therefore, since it can play the role of two light guide plates, it is possible to reduce the number of parts in a device having a display unit on both the front surface side and the back surface side, and to reduce the weight, size and thickness of the device. Can be planned.

Further, in the light guide plate according to the present invention, as described in claim 2, a plurality of front light reflection patterns and a plurality of backlight reflection patterns are provided in a mixed manner on the facing surface. It is characterized by being Thus, one light guide plate can be applied to a device having a plurality of display units on both the front surface side and the back surface side.

Further, as described in claim 3, the light guide plate according to the present invention is formed of a translucent material and has one surface and the other surface opposite to the one surface. In the above, the one surface and the other surface are each provided with a reflection pattern capable of reflecting light. With this, since reflection patterns can be provided on one surface and the other surface of one light guide plate, light can be emitted in two directions with one light guide plate. Therefore, since it can play the role of two light guide plates, it is possible to reduce the number of parts of the light guide plate in a device having a display unit on both the front surface side and the back surface side, and to reduce the weight and size of the device. The thickness can be reduced. In addition, since reflection patterns can be provided on two surfaces of one light guide plate, the degree of freedom in designing a device having a display unit on both the front surface side and the back surface side (position of liquid crystal display panel, etc.) is increased. be able to.

Further, in the light guide plate according to the present invention, as described in claim 4, the light guide plate is arranged such that the reflection pattern provided on the one surface opposes the reflection pattern provided on the other surface. It is characterized by being. With this, since reflection patterns can be provided at the opposite positions on the front and back of one light guide plate, liquid crystal display panels can be arranged on the front and back at the same position, and the display can be provided on both the front and back sides. It is possible to reduce the weight, the size, and the thickness of the device including the unit.

Further, in the light guide plate according to the present invention, as described in claim 5, the light guide plate is arranged so that the reflection pattern provided on the one surface does not face the reflection pattern provided on the other surface. It is characterized by being. Accordingly, since reflection patterns can be provided on the front and back surfaces of one light guide plate at positions not facing each other, the liquid crystal display panel can be arranged on the back surface side at a position different from the position of the front side liquid crystal display panel. The degree of freedom in arranging the display panel is increased.

Further, as described in claim 6, the liquid crystal display device according to the present invention has the light guide plate according to claim 1 and a light emitting surface side of the light guide plate facing the front light reflection pattern. A reflective liquid crystal display panel arranged,
The liquid crystal display panel may include a transmissive or semi-transmissive liquid crystal display panel disposed on a light emitting surface side of the light guide plate facing the backlight reflection pattern, and a light source that emits light to the light guide plate. Thereby, light can be emitted to two liquid crystal display panels with one light guide plate. Therefore, it is possible to reduce the weight, the size, and the thickness of the device including the display units on both the front surface side and the back surface side.

Further, in the liquid crystal display device according to the present invention, as described in claim 7, a plurality of front light reflection patterns and a plurality of backlight reflection patterns are mixedly provided on the facing surface. It is characterized by being As a result, light can be emitted to a plurality of liquid crystal display panels with one light guide plate, and a device having a plurality of display units on both the front surface side and the back surface side can be made lighter, smaller, and thinner. Can be realized.

Further, as described in claim 8, a liquid crystal display device according to the present invention is arranged on the light guide plate according to claim 3 and on the light emitting surface side facing the reflection pattern of the light guide plate. A liquid crystal display panel and a light source for emitting light to the light guide plate are provided. By this, 1
Since it is possible to arrange the liquid crystal display panel so as to face one surface and the other surface of the one light guide plate, one light guide plate is used.
Light can be emitted to one liquid crystal display panel. Therefore, it is possible to reduce the weight, the size, and the thickness of the device including the display units on both the front surface side and the back surface side. In addition, since the liquid crystal display panel can be provided on the two surfaces of one light guide plate, the degree of freedom in designing the device (the position of the liquid crystal display panel, etc.) can be increased.

Further, in the liquid crystal display device according to the present invention, as described in claim 9, the reflection pattern provided on the one surface is opposed to the reflection pattern provided on the other surface. It is characterized by being arranged. With this, the liquid crystal display panel can be provided so as to be superposed on one light guide plate, so that further size reduction and weight reduction can be achieved.

Also, in the liquid crystal display device according to the present invention, as described in claim 10, the reflection pattern provided on the one surface does not face the reflection pattern provided on the other surface. It is characterized by being arranged.
Accordingly, since reflection patterns can be provided on the front and back surfaces of one light guide plate at positions not facing each other, the liquid crystal display panel can be arranged on the back surface side at a position different from the position of the front side liquid crystal display panel. The degree of freedom in arranging the display panel is increased.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a light guide plate and a liquid crystal display device according to the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG. 1 is an explanatory view showing a light guide plate and a liquid crystal display device according to the first embodiment. 2 is a perspective view (a) of the light guide plate and the light source of FIG. 1, and a perspective view (b) of the liquid crystal display panel of FIG. As shown in FIG. 1 or FIG. 2, the liquid crystal display device 1 according to the first embodiment is a reflection type in which a light guide plate 2 and a front light reflection pattern 3 of the light guide plate 2 are arranged to face each other. Liquid crystal display panel 4, a transmissive or semi-transmissive liquid crystal display panel 6 arranged so as to face the backlight reflection pattern 5 of the light guide plate 2, and a light source 7 for emitting light 8 to the light guide plate 2. And are provided.

According to the liquid crystal display device 1, when the light 8 is emitted from the light source 7, the light 8 is reflected by the backlight reflection pattern 5, and the reflected light 8 is reflected by the liquid crystal display panel 6 (transmissive type or semi-transparent type). The content displayed on the liquid crystal display panel 6 is visually perceived by the observer 9 through the transparent type.

Further, by emitting light 8 from the light source 7, the light 8 is reflected by the front light reflection pattern 3,
The reflected light 8 is reflected by the liquid crystal display panel 4 (reflective type), so that the content displayed on the liquid crystal display panel 4 is visually observed by an observer 9.

The light guide plate 2 is made of a light-transmissive material (methacrylic resin, polycarbonate resin, olefin polymer, etc.) and has one surface as a light emitting surface 2a and the other surface facing the light emitting surface 2a. The surface 2b is provided with a reflection pattern 3 for a front light and a reflection pattern 5 for a backlight, which can reflect light and have different reflection patterns, on the facing surface 2b. Liquid crystal display panels 4 and 6 are arranged to face the light emitting surface 2a.

As the reflection pattern 3 for the front light, for example, as shown in FIG. 2A, a pattern of triangular concave and convex grooves acting as a prism is used, which is formed in the width direction of the light guide plate 2. As the backlight reflection pattern 5, for example, a textured pattern or an uneven pattern such as print dots formed by screen printing is used. Alternatively, a prism pattern shape may be used as in the front light. These reflection patterns are for improving the brightness and uniformity of the light emitted from the light guide plate 2.

Since the front light reflection pattern 3 and the backlight reflection pattern 5 can be simultaneously formed by integral molding, they can be manufactured in the same number of steps as the conventional light guide plate manufacturing process. Is.

The light source 7 is, for example, as shown in FIG. 2A, constituted by a rod-shaped light guide body 7b having light emitting diodes 7a, 7a provided at both ends thereof, and the light 8 from the light guide body 7b is linearly emitted. Used as a light source. Further, as the linear light source, a chemical fluorescent lamp (CFL) or the like can be used without using the rod-shaped light guide. It is also possible to use, as the light source 7, a plurality of point light sources (light emitting diodes or the like) arranged at the edge of the light guide plate 2 without using the linear light source.

As a result, the light 8 can be emitted to the two liquid crystal display panels 4 and 6 by one light guide plate 2, so that the number of light guide plates 2 can be reduced. In addition, by providing the reflection pattern 3 for the front light and the reflection pattern 5 for the backlight on the same surface (opposing surface 2b) of the light guide plate 2, the processing of the patterns 3 and 5 is facilitated.

Further, the light guide plate 2 can be provided on the facing surface 2b in a mixture of a plurality of front light reflection patterns 3 ... And back light reflection patterns 5.
As a result, it is possible to deal with various variations of the device configuration, and thus the applicable range of the liquid crystal display device 1 can be expanded.

In the first embodiment, the example in which the light source 7 is provided on the backlight reflection pattern 5 side of the light guide plate 2 has been described, but the light source 7 is the front light reflection pattern 3.
It is also possible to prepare for the side. In this case, if a point light source is used, uniform surface emission of the light guide plate cannot be obtained, and thus the light source 7 needs to use a linear light source.

However, as shown in FIG. 1 or FIG. 2, in the structure in which light is incident from the backlight reflection pattern 5 side, the end face of the area of the light guide plate of the backlight reflection pattern 5 (the backlight reflection pattern 5 And the front light reflection pattern 3), when the light is emitted to the area of the light guide plate of the front light reflection pattern 3, this end surface serves as a linear light source, so that the front light reflection pattern 3 side is also uniform. It is possible to obtain a flat surface emission.

(Second Embodiment) Next, a second embodiment will be described. As shown in FIG. 3, the liquid crystal display device 10 according to the present embodiment is a transmissive type or a semi-transmissive type which is arranged so as to face the light guide plate 12 and the backlight reflection patterns 13 a and 13 b of the light guide plate 12. Type liquid crystal display panels 14a and 14b, and a light source 7 for emitting light 8 to the light guide plate 12 are provided.

The light guide plate 12 is made of a translucent material (methacrylic resin, polycarbonate resin, olefin polymer, etc.) and has one surface 12a and one surface 12a.
It has the other surface 12b facing a, and the one surface 12a and the other surface 12b are provided with backlight reflection patterns 13a and 13b capable of reflecting light, respectively, so as not to face each other.

Thus, the liquid crystal display panel 14a is arranged so as to face one surface 12a of the light guide plate 12 and the surface opposite to the surface 12a, and the other surface 1a.
Since the liquid crystal display panel 14b can be arranged so as to face the surface on the 2b side and the surface opposite to the surface 12b, one light guide plate 12 emits the light 8 to the two liquid crystal display panels 14a and 14b. Therefore, the number of light guide plates 12 can be reduced. In addition, since the backlight reflection patterns 13 and 13 can be provided on the two surfaces of the light guide plate 12,
The degree of freedom in design can be increased. The light source 7 is composed of a light emitting diode and a rod-shaped light guide as in the first embodiment.

According to the liquid crystal display device 10, when the light 8 is emitted from the light source 7, the light 8 is reflected by the backlight reflection patterns 13a and 13b, and the reflected light 8 is reflected on the liquid crystal display panels 14a and 14b. The contents displayed on the liquid crystal display panels 14a and 14b by being respectively transmitted are visually observed by the observers 9 and 9.

(Third Embodiment) Next, a third embodiment will be described. As shown in FIG. 4, the liquid crystal display device 20 according to the present embodiment includes a light guide plate 22 and front light reflection patterns 23 a and 23 b of the light guide plate 22.
Reflective liquid crystal display panel 2 arranged to face
4a and 24b, and a light source 7 that emits light 8 to the light guide plate 22 are provided.

The light guide plate 22 is made of a translucent material (methacrylic resin, polycarbonate resin, olefin polymer, etc.) and has one surface 22a and one surface 22a.
It has the other surface 22b facing a, and front surface reflection patterns 23a and 23b capable of reflecting light are provided on the one surface 22a and the other surface 22b so as not to face each other. As a result, the surface 23 of the light guide plate 22 is
By arranging the liquid crystal device panel 24a (24b) so as to face the surface a (23b) and the surface opposite to the surface 23a (23b), the same effect as that of the second embodiment can be obtained. .

According to the liquid crystal display device 20, when the light 8 is emitted from the light source 7, the light 8 is reflected by the front light reflection patterns 23a and 23b, and the reflected light 8 is reflected by the liquid crystal display panels 24a and 24b. The contents displayed on the liquid crystal display panels 24a and 24b by being reflected are observed by the observer 9,
Visually by 9. The light source is composed of a light emitting diode and a rod-shaped light guide as in the above-described embodiment.

(Fourth Embodiment) Next, a fourth embodiment will be described. As shown in FIG. 5, the liquid crystal display device 30 according to the present embodiment includes a light guide plate 32 and a transmissive type or a semi-transmissive type arranged so as to face the backlight reflection patterns 33 a and 33 b of the light guide plate 32. The liquid crystal display panels 34a and 34b of the mold and the light source 7 for emitting the light 8 to the light guide plate 32 are provided.

The light guide plate 32 is made of a translucent material (methacrylic resin, polycarbonate resin, olefin polymer, etc.) and has one surface 32a and one surface 32a.
It has the other surface 32b on the opposite side that faces a, and the one surface 32a and the other surface 32b are provided with backlight reflection patterns 33a and 33b capable of reflecting light, respectively.

As a result, the same effect as that of the second embodiment can be obtained, and in addition, since the liquid crystal display panels 34a and 34b can be superposed on the single light guide plate 32, a further compact structure can be obtained. And weight reduction.

According to this liquid crystal display device 30, when the light 8 is emitted from the light source 7, the light 8 is reflected by the backlight reflection patterns 33a and 33b, and the reflected light 8 is reflected on the liquid crystal display panels 34a and 34b. The contents displayed on the liquid crystal display panels 34a and 34b by being transmitted are observed by the observers 9 and 9.
To be seen by. The light source is composed of a light emitting diode and a rod-shaped light guide.

[0042]

As described above in detail, according to the invention described in claim 1, since one light guide plate can serve as two light guide plates, the front surface side and the back surface side can be fulfilled. It is possible to provide a light guide plate that can reduce the weight, size, and thickness of the device by reducing the number of parts of the light guide plate in a device having a display unit on both sides.

According to the invention described in claim 2,
Since the front light reflection pattern and the back light reflection pattern are provided in a mixed manner, one light guide plate can be applied to devices equipped with multiple display units on both the front surface side and the back surface side. It is possible to provide a light guide plate capable of expanding the range.

According to the invention described in claim 3,
By emitting light in two directions with one light guide plate, the light guide plate functions as two light guide plates, so that the number of parts of the light guide plate in the device having the display unit on both the front surface side and the back surface side is reduced. Therefore, the device can be made lighter, smaller, and thinner. In addition, since reflection patterns can be provided on two surfaces of one light guide plate, the degree of freedom in designing a device having a display unit on both the front surface side and the back surface side (position of liquid crystal display panel, etc.) is increased. It is possible to provide a light guide plate.

According to the invention described in claim 4,
Since reflection patterns can be provided at the opposite positions on the front and back of one light guide plate, liquid crystal display panels can be arranged on the front and back at the same position, and display units are provided on both front and back sides. It is possible to provide a light guide plate that can reduce the weight, size, and thickness of the device.

According to the invention described in claim 5,
Since the reflection patterns can be provided on the front and back surfaces of one light guide plate at positions not facing each other, the liquid crystal display panel can be arranged on the back surface side at a position different from the position of the liquid crystal display panel on the front surface side. It is possible to provide a light guide plate with increased flexibility.

According to the invention described in claim 6,
Light can be emitted to two liquid crystal display panels with one light guide plate. Therefore, it is possible to provide a liquid crystal display device capable of achieving weight reduction, size reduction, and thickness reduction of a device including display portions on both the front surface side and the back surface side.

According to the invention described in claim 7,
Light can be emitted to a plurality of liquid crystal display panels with one light guide plate, and a device having a plurality of display units on both the front surface side and the back surface side can be made lighter, smaller, and thinner. A liquid crystal display device that can be provided can be provided.

According to the invention described in claim 8,
Since the liquid crystal display panel can be arranged so as to face one surface and the other surface of one light guide plate, it is possible to emit light to the two liquid crystal display panels with one light guide plate. Therefore, it is possible to reduce the weight, the size, and the thickness of the device including the display units on both the front surface side and the back surface side. In addition, since the liquid crystal display panel can be provided on the two surfaces of one light guide plate, it is possible to provide a liquid crystal display device which can increase the degree of freedom in designing the device (position of the liquid crystal display panel, etc.).

According to the invention described in claim 9,
Since the liquid crystal display panel can be provided so as to be superposed on one light guide plate, it is possible to provide a liquid crystal display device that can be further reduced in size and weight.

According to the tenth aspect of the invention, since the reflection patterns can be provided on the front and back surfaces of one light guide plate at positions not facing each other, the back surface at a position different from the position of the front side liquid crystal display panel. It is possible to provide a liquid crystal display device in which a liquid crystal display panel can be arranged on the side, and the degree of freedom in arranging the liquid crystal display panel can be increased.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a first embodiment of a light guide plate and a liquid crystal display device according to the present invention.

2 is a perspective view (a) of the light guide plate and the light source of FIG. 1, and a perspective view (b) of the liquid crystal display panel of FIG.

FIG. 3 is an explanatory diagram showing a second embodiment of a light guide plate and a liquid crystal display device according to the present invention.

FIG. 4 is an explanatory view showing a third embodiment of a light guide plate and a liquid crystal display device according to the present invention.

FIG. 5 is an explanatory diagram showing a fourth embodiment of a light guide plate and a liquid crystal display device according to the present invention.

[Explanation of symbols]

1, 10, 20, 30 Liquid crystal display device 2, 12, 22, 32 Light guide plate 2a Light emitting surface (one surface) 2b Opposing surface (other surface) 3, 23a, 23b Front light reflection pattern 4, 24a, 24b Reflective liquid crystal display panel 5, 13a, 13b, 33a, 33b Reflective pattern for backlight 6, 14a, 14b, 34a, 34b Transmissive or semi-transmissive liquid crystal display panel 7 Light source 7a Light emitting diode 7b Rod-shaped light guide 8 Light 12a, 22a, 32a One surface 12b, 22b, 32b The other surface

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02F 1/13357 G02F 1/13357 // F21Y 101: 02 F21Y 101: 02 (72) Inventor Masanori Mori Saitama Prefecture 6-1-1 Fujimi, Tsurugashima City Pioneer Precision Co., Ltd. (72) Inventor Hideki Ozawa 6-1-1 1-1 Fujimi, Tsurugashima City, Saitama Pioneer Precision Co., Ltd. F term (reference) 2H038 AA55 BA06 2H091 FA23X FA23Z FD01 FD04 LA11 LA13 MA10

Claims (10)

[Claims] 1. A light guide plate, which is made of a light-transmitting material and has one surface as a light emitting surface and the other surface facing the light emitting surface as a facing surface, wherein light can be reflected on the facing surface. A light guide plate having a front light reflection pattern and a back light reflection pattern having different reflection patterns. 2. The light guide plate according to claim 1, wherein a plurality of front light reflection patterns and a plurality of backlight reflection patterns are provided in a mixed manner on the facing surface. 3. A light-transmitting material, which is formed on one surface and
In the light guide plate having the other surface facing the one surface, a reflection pattern capable of reflecting light is provided on each of the one surface and the other surface. 4. The light guide plate according to claim 3, wherein the reflection pattern provided on the one surface is arranged so as to face the reflection pattern provided on the other surface. 5. The light guide plate according to claim 3, wherein the reflection pattern provided on the one surface is arranged so as not to face the reflection pattern provided on the other surface. 6. The light guide plate according to claim 1, a reflective liquid crystal display panel arranged on the light emitting surface side of the light guide plate facing the front light reflection pattern, and a backlight for the light guide plate. A liquid crystal display device comprising: a transmissive or semi-transmissive liquid crystal display panel arranged on a light emitting surface side facing a reflection pattern; and a light source for emitting light to the light guide plate. 7. The liquid crystal display device according to claim 6, wherein a plurality of front light reflection patterns and a plurality of backlight reflection patterns are provided in a mixed manner on the facing surface. 8. The light guide plate according to claim 3, a liquid crystal display panel arranged on a light emitting surface side facing the reflection pattern of the light guide plate, and a light source for emitting light to the light guide plate. A liquid crystal display device characterized by the above. 9. The liquid crystal display device according to claim 8, wherein the reflection pattern provided on the one surface is arranged so as to face the reflection pattern provided on the other surface. . 10. The liquid crystal display device according to claim 8, wherein the reflection pattern provided on the one surface is arranged so as not to face the reflection pattern provided on the other surface. .