KR100312275B1 - Front-illuminating device and a reflection-type liquid crystal display using such a device - Google Patents

Abstract

The front lighting device according to the present invention is used by being disposed on the front surface of a light such as a reflective liquid crystal display device and has a light source and a light guide. The light guide includes an incidence plane that enters light (a light source light) from a light source, a first exit plane that emits light toward an object to be illuminated, and a second exit plane that emits reflected light from the light object opposite thereto. Equipped with. This second output surface has a step shape in which the inclined portion and the flat portion are alternately arranged. The light source light emitted from the first emission surface to the object to be illuminated is reflected by the object, and the reflected light reaches the observer's side from the first emission surface through the flat portion. At this time, a component parallel to the flat portion of the light source light is reflected by the inclined portion and irradiated onto the object to be illuminated. Therefore, in this invention, the brighter front illumination device which improved the utilization efficiency of light source light can be provided.

Description

FRONT-ILLUMINATING DEVICE AND A REFLECTION-TYPE LIQUID CRYSTAL DISPLAY USING SUCH A DEVICE}

The present invention is disposed between a lighted object and an observer, and is used to irradiate light on the lighted object and to transmit the reflected light so that the viewer can see the reflected light from the lighted object, and the front light. A reflective liquid crystal display device comprising the device as an auxiliary light source.

Unlike other displays called Cathode Ray Tube (CRT), Plasma Display Panel (PDP), or Electro Luminescence (EL), liquid crystal displays do not emit light by controlling the amount of light transmitted by a particular light source Display text or images.

Conventional liquid crystal display devices (hereinafter referred to as LCDs) are broadly classified into transmissive LCDs and reflective LCDs. In the transmissive LCD, a surface emitting light source such as a fluorescent tube or EL as a light source (back light) is disposed on the back of the liquid crystal cell.

On the other hand, since the reflective LCD displays the display using ambient light, there is an advantage that power consumption is small without requiring back light. In addition, in a very bright place where direct sunlight encounters, the display of the light emitting display or the transmissive LCD is almost invisible, but the display of the reflective LCD shows more clearly. For this reason, reflective LCDs have been applied to portable information terminals and mobile computers, which are increasingly in demand.

However, the reflective LCD has the following problems. That is, since the reflective LCD uses ambient light, the degree to which the display brightness depends on the surrounding environment is very high. For this reason, display may not be recognized at all especially in the darkness, such as night. In particular, in a reflective LCD using a color filter for colorization or a reflective LCD using a polarizing plate, such a problem is particularly large, and auxiliary lighting is required in case a case where sufficient ambient light is not obtained.

However, the reflective LCD is provided with a reflecting plate on the back of the liquid crystal cell, and it is impossible to use the back light such as the transmissive LCD. Although a device called a semi-transmissive LCD using a half mirror as a reflecting plate has been proposed, its display characteristics are halfway, which cannot be said to be a transmissive type or a reflective type, and thus it is considered to be difficult to use.

Thus, conventionally, a front light system for disposing on the front side of a liquid crystal cell has been proposed as an auxiliary illumination of a reflective LCD when the surroundings are dark. This front light system generally includes a light guide and a light source disposed on the side of the light guide. The light source light incident from the light guide side surface propagates inside the light guide, reflects in a shape made on the light guide surface, and exits to the liquid crystal cell side. The emitted light is dimmed in accordance with the display information while passing through the liquid crystal cell, and is reflected by the reflecting plate arranged on the rear side of the liquid crystal cell. The reflected light passes through the light guide again and exits to the observer side. Thus, the observer can recognize the display even when the amount of ambient light is insufficient.

Such a front light is disclosed, for example, in Japanese Patent Laid-Open No. 5-158034, SID DIGEST P. 375 (1995) and the like.

Here, the operation principle of the front light system disclosed in SlD DIGEST P. 375 (1995) will be briefly described with reference to FIG. In the above-mentioned front light system, one side surface of the light guide body 104 having the interface 101 formed from the flat portion 101a and the inclined portion 101b is formed at an incident surface on which light from the light source 106 is incident. 105). In other words, the light source 106 is disposed at a position opposite to the incident surface 105 of the light guide 104.

Some of the light that enters the light guide 104 from the light source 106 through the incident surface 105, some go straight, and some enter the interface (101 · 108) between the light guide 104 and the surrounding medium do. At this time, if the peripheral medium of the light guide 104 is air, and the refractive index of the light guide 104 is about 1. 5, Snell's law (Equation 1) shows that the interface 101. It can be seen that light having an incident angle of about 41.8 ° or more is totally reflected at the interface 101 占.

θ _c = arcsin (n ₂ / n ₁ )

Provided that n ₁ represents the refractive index of the first medium (here, the light guide 104),

n ₂ is the index of refraction of the second medium (here air),

θ ₁ is the angle of incidence from the light guide 104 to the interface 101,

θ ₂ is the exit angle from the interface 101 to the second medium,

θ _c is the critical angle.

Among the light incident on the interface 101 · 108, the light totally reflected by the inclined portion 101b which is the reflective surface and the light reflected by the inclined portion 101b of the interface 101 after totally reflecting on the interface 108 are It enters into the liquid crystal cell 110. The light incident on the liquid crystal cell 110 is dimmed by a liquid crystal layer (not shown), and then is reflected by the reflecting plate 111 provided on the rear surface of the liquid crystal cell 110, and is incident again on the light guide 104 to form a flat portion. It penetrates 101a and exits to the observer 109 side.

In addition, the light passing through the incident surface 105 from the light source 106 and entering the flat portion 101a instead of the inclined portion 101b is between the interface 101 and the interface 108. It propagates by repeating the total reflection until it reaches. Moreover, the area of the inclined portion 101b seen from the observer 109 side is formed sufficiently smaller than the area of the flat portion 101a.

Here, the conventional front light system has the following problems in its structure.

(1) As shown in FIG. 52, light which cannot reach the inclined portion 101b even if the total reflection is repeated, or light which is incident almost perpendicularly to the incident surface 105, faces the incident surface 105. It becomes the light 114 which exits the light guide body 104 from the surface 107, and cannot be used for display. That is, the utilization efficiency of light is bad.

(2) The shape of the interface 101 composed of the inclined portion 101b and the flat portion 101a is similar to the shape of exactly flattening the vertex of the prism sheet, and as shown in FIG. 52, the ambient light 115 ) Is easily reflected to the observer 109 side, leading to deterioration of display quality.

These problems are common to most of the conventional front light systems. For this reason, even with such a front light system, it is not possible to illuminate an object to be illuminated (reflected LCD, etc.) with a sufficient amount of light. Therefore, the improvement of the utilization efficiency of the light source light of a front light system is calculated | required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to improve the utilization efficiency of the light source light, and to provide a uniform and brighter illumination for the object to be illuminated, and a reflection using the front illumination device. It is providing the liquid crystal display device of a type | mold.

In order to solve the above problems the front lighting device according to the present invention,

Has a light source disposed in front of the light source and the light object,

The light guide includes an incidence surface that incidents light from a light source, a first emission surface that emits light toward an object to be illuminated, and a second emission surface that emits reflected light from an object to be illuminated against the first emission surface. With that,

The inclination part which the said 2nd emitting surface mainly reflects the light from a light source toward the 1st emitting surface, and the flat part which mainly transmits the reflected light from the to-be-illuminated object are formed in the staircase shape alternately arrange | positioned.

In the above-described configuration, illumination light is emitted from the first emission surface to the object to be illuminated, and the reflected light from the illumination object is returned from the first emission surface to the light guide body again, and is transmitted through the flat portion of the second emission surface to the observer's side. To reach. In the light guide member having the above-described configuration, the second emission surface facing the first emission surface is formed in a step shape in which the inclined portion and the flat portion are alternately arranged, and the inclined portion located between the flat portion and the flat portion is mainly a light source. Since the light from the light is reflected toward the first emission surface, all of the components parallel to the flat portion of the light incident from the light source are reflected at the inclined portion and irradiated to the illuminated object from the first emission surface. Therefore, compared with the conventional structure which has a light guide body formed in substantially flat plate shape, in the front lighting apparatus of this invention, the component of the light which propagates parallel to a flat part does not leak out of the light guide body, but is irradiated with a to-be-illuminated object. . Therefore, the utilization efficiency of the light source light can be improved to provide a brighter front lighting device.

In order to solve the said subject, the said front illumination apparatus further includes the 2nd light guide body which averages the luminance distribution of the emitted light from the said 1st light emission surface, when the said light guide body is made into a 1st light guide body.

In the above configuration, since the first light guide is formed in a step shape, the distance from the inclined portion of the second emission surface to the first emission surface is reduced in proportion to the distance from the light source. For this reason, the luminance distribution of light emitted from the first emission surface may not be uniform. The above-mentioned structure is equipped with the 2nd light guide body, and the luminance distribution of the emitted light to a to-be-illuminated object is averaged. As a result, it is possible to provide a front illumination device that functions as a surface light source without luminance unevenness.

In order to solve the said subject, the said front lighting apparatus further includes the optical compensation plate which matched the emission direction of the emission light from the flat part on the 2nd emission surface, and the emission light from the inclination part.

In the above configuration, since the second emission surface is formed in a staircase shape in which the flat portion and the inclined portion are alternately arranged, the reflected light from the illuminated object incident on the light guide from the first emission surface is the flat portion and the inclined portion of the second emission surface. It radiates from each other in a mutually different direction, and there exists a possibility of causing the blur of an image of a to-be-illuminated object. For this reason, by providing the optical compensation plate which matched the emission direction from the light emission from the flat part of the 2nd emission surface and the light emission from the inclination part, it becomes possible to obtain a clear image of a to-be-illuminated object.

In order to solve the above problem, the front lighting apparatus further includes a prism sheet, a diffusion plate, and the like that restrict the expansion of light from the light source between the light source and the incident surface.

In the above configuration, the light from the light source is mainly reflected at the inclined portion of the second emission surface, but in order to reduce the component leaking out of the light guide body without total reflection at the inclined portion, the degree of directivity to the light from the light source is somewhat increased. It is desirable to reduce the component incident on the inclined portion at an angle smaller than the critical angle. To this end, the above-described configuration includes a prism sheet and a diffusion plate for restricting the expansion of light from the light source, so that the leakage light from the inclined portion is less, so that the utilization efficiency of the light is further improved and the image of the object to be blurred is blurred or blurred. This is avoided. As a result, the front lighting apparatus as a surface light source from which a bright and clear object image to be obtained is realized.

In order to solve the above problems, the reflective liquid crystal display device according to the present invention includes a reflective liquid crystal element having a reflective plate,

The front illuminating device which has the said structure is arrange | positioned in front of the said reflection type liquid crystal element.

In the above configuration, when there is a sufficient amount of ambient light, for example, outdoors in the middle of the day, the front lighting device is turned off while the front lighting device can be turned on and used when a sufficient amount of ambient light is not obtained. As a result, it becomes possible to provide a reflective liquid crystal display device that can realize bright high quality display at any time regardless of the surrounding environment.

Another reflective liquid crystal display device according to the present invention is a reflective liquid crystal display device having a front illumination device having the optical compensation plate on the front surface of a reflective liquid crystal element having a reflection plate in order to solve the above problems.

While the optical compensation plate is flexible to a predetermined pressure,

On each of the optical compensation plate and the second emission surface, a pair of transparent electrodes for detecting a position where pressure is applied by contacting each other is provided.

In the above configuration, the front lighting device functions as a so-called touch panel. That is, when a certain position on the surface of the optical compensation plate is pressed with a pen or the like, for example, the optical compensation plate is bent so that the pair of transparent electrodes provided on the optical compensation plate and the second emission surface respectively contact each other at the above positions. Recognizing this position as a coordinate, a reflection type liquid crystal display device capable of pen input with respect to the contents displayed on the liquid crystal element is realized.

Still other objects, features, and advantages of the present invention can be fully understood from the descriptions given below. Further advantages of the present invention will become apparent from the following description with reference to the accompanying drawings.

1 is a cross-sectional view showing a configuration of a reflective LCD according to one embodiment of the present invention.

2A, 2B, and 2C show the shape of the light guide of the front light included in the reflective LCD shown in FIG. 1, FIG. 2A is a plan view of the light guide viewed from above the normal direction of the flat portion, and FIG. Fig. 2C is a cross-sectional view of the light guide taken from the normal direction of the incident surface, and the light guide is cut into a cross section in which the longitudinal direction of the light source is normal.

3A, 3B, and 3C are explanatory views showing the behavior of the light from the light source in the light guide.

4 is an explanatory diagram showing the behavior of light reflected by a reflecting plate of a reflective LCD;

5 is an explanatory diagram of a measurement system for measuring the light intensity of the front light shown in FIGS. 2A to 2C.

FIG. 6 is a graph showing a measurement result of light intensity of the front light shown in FIGS. 2A to 2C.

Fig. 7A is an explanatory diagram showing the relationship between the outgoing light from the emissive display and the ambient light, and Fig. 7B is an explanatory diagram showing the relation between the outgoing light from the reflective LCD shown in Fig. 1 and the ambient light.

8 is a cross-sectional view showing a configuration of a reflective LCD according to another embodiment of the present invention.

FIG. 9A is a cross-sectional view showing a uniform distance from the inclined portion of the light guide to the surface serving as the exit surface of the front light system in the front light system with the reflective LCD shown in FIG. For comparison, in the front light with a reflective LCD shown in Fig. 1, a cross-sectional view showing that the distance from the inclined portion to the surface serving as the exit surface of the front light is not uniform.

10A and 10B are explanatory views showing measurement systems for measuring the luminance distribution of the irradiation light by the front lights shown in Figs. 9A and 9B, respectively.

11A and 11B are graphs respectively showing measurement results of luminance distribution of irradiation light by front lights shown in FIGS. 9A and 9B, respectively.

12 is a cross-sectional view showing the configuration of a reflective LCD as still another embodiment according to the present invention;

FIG. 13 is a schematic diagram showing the behavior of light in a front light system with a reflective LCD shown in FIG. 12; FIG.

FIG. 14 is a graph showing a measurement result of luminance distribution of irradiation light of a front light system with a reflective LCD shown in FIG. 12;

Fig. 15 is an explanatory diagram showing a principle of blurring or blurring of an image in a reflective LCD according to still another embodiment of the present invention;

Fig. 16 is a sectional view showing an enlarged portion of the inclined portion of the light guide of the reflective LCD, showing a structure in which a metal reflective film is provided on the inclined portion.

17A to 17E are cross-sectional views illustrating a step of forming the metal reflective film.

FIG. 18 is a schematic diagram showing the behavior of light when there is no metal reflective film in the light guide shown in FIG. 16; FIG.

19 is a sectional view showing a modification of the configuration shown in FIG. 16;

20 is a cross-sectional view showing the configuration of a reflective LCD as still another embodiment according to the embodiment of the present invention;

Fig. 21 is a schematic diagram showing the behavior of light between the light guide and the optical compensation plate in the reflective LCD.

22A, 22B, and 22C show the configuration of a reflective LCD as a modification of the configuration shown in FIG. 20, and FIG. 22A is a sectional view of this reflective LCD, and FIGS. 22B and 22C are optical of this reflective LCD. Sectional drawing which showed the structural example of a compensation plate, respectively.

Fig. 23 is a sectional view showing the structure of a touch panel with a reflective LCD as another form according to the embodiment of the present invention.

Fig. 24 is an explanatory diagram showing the configuration of the reflective electrode provided in the touch panel.

Fig. 25 is a plan view showing a structure for detecting coordinates of a position pressed by a pen in the touch panel.

Fig. 26 is a cross-sectional view showing a state when a part of the touch panel is pressed with a pen.

Fig. 27 is a sectional view showing the structure of a reflective LCD as still another embodiment according to the present invention.

FIG. 28 is an explanatory diagram for explaining a condition under which light incident from an incident surface is totally reflected at an inclined portion in the light guide of the reflective LCD shown in FIG. 27; FIG.

FIG. 29 is a graph showing condensing characteristics of a prism sheet with a reflective LCD shown in FIG. 27;

30A and 30B are explanatory views showing another configuration example that can be applied to limit the expansion of incident light to the reflective LCD shown in FIG. 27;

31A, 31B, and 31C are sectional views showing the behavior of light in the light guide together with the configuration of the light guide provided with the reflective LCD according to another embodiment of the present invention.

32 is a cross-sectional view showing a configuration of a reflective LCD as still another embodiment according to the present invention;

Fig. 33 is an explanatory diagram for explaining the condition of the inclination angle of the incident surface of the front light of the reflective LCD shown in Fig. 32;

Fig. 34 is a perspective view showing the structure of a reflective LCD as another form according to the embodiment of the present invention.

35 is a perspective view showing an example of use of a lighting apparatus as still another embodiment according to the embodiment of the present invention.

36 is a plan view illustrating an example of use of the lighting apparatus illustrated in FIG. 35.

Fig. 37 is a sectional view showing the structure of a reflective LCD according to still another embodiment of the present invention.

38A, 38B, and 38C show the shape of the light guide of the front light with the reflective LCD shown in FIG. 37, FIG. 38A is a plan view of the light guide viewed from above the normal direction of the flat portion, and FIG. 38B is a light guide. Fig. 38C is a cross-sectional view of the body taken from the normal direction of the incidence surface, and Fig. 38C is a cross-sectional view of the light guide being cut into a cross section of the light source in the longitudinal direction.

FIG. 39 is an explanatory diagram for explaining a configuration of a flat portion and an inclined portion in the light guide shown in FIG. 38; FIG.

40A and 40B are explanatory views showing the behavior in the light guide of light from a light source.

FIG. 41 is a graph showing the relationship between the distance from a light source and the luminance in the front light with the reflective LCD shown in FIG. 37; FIG.

FIG. 42 is a graph showing the characteristics of the angle of emitted light in the front light with the reflective LCD shown in FIG. 37; FIG.

Fig. 43 is a sectional view showing the structure of a reflective liquid crystal cell with a reflective LCD shown in Fig. 37;

44A to 44E are process charts showing the method for forming a reflective electrode in the reflective liquid crystal cell shown in FIG. 43;

45 is a graph showing the reflectance angle dependence of the reflective electrode in the reflective liquid crystal cell shown in FIG. 43;

46 is a cross-sectional view showing another example of the reflective liquid crystal cell shown in FIG. 43;

FIG. 47 is a plan view showing the structure of a pixel, a scan line, and a signal line in the reflective liquid crystal cell shown in FIG. 43;

FIG. 48 is a graph showing the luminance and luminance distribution characteristics of the emitted light in the front light with the reflective LCD shown in FIG. 37; FIG.

Fig. 49 is a sectional view showing the configuration of a reflective LCD as still another embodiment according to the present invention.

50A and 50B are graphs respectively showing measurement results of luminance distributions of illumination light in a front light with a reflective LCD shown in FIG. 49 and a conventional front light;

Fig. 51 is a sectional view showing the behavior of light in this reflective LCD, with a schematic configuration of a conventional reflective LCD having an auxiliary illumination function;

Fig. 52 is a sectional view showing the behavior of light in the conventional reflective LCD.

<Explanation of symbols for main parts of drawing>

10: reflection type liquid crystal cell

17: reflector

20: front lighting device

23: second exit surface

29: gap

47: metal reflective film

64: reward

Embodiment 1

EMBODIMENT OF THE INVENTION When one Embodiment of this invention is described based on drawing, it is as follows.

As shown in FIG. 1, the reflective LCD according to the present embodiment is configured to include a front light 20 (front lighting device) on the front surface of the reflective liquid crystal cell 10 (reflective liquid crystal element).

The front light 20 is mainly comprised by the light source 26 and the light guide 24. The light source 26 is a linear light source, such as a fluorescent tube, for example, and is arrange | positioned along the side surface (incident surface 25) of the light guide 24. As for the light guide 24, the interface 28 (1st output surface) by the side of the liquid crystal cell 10 is formed flat. On the other hand, in the light guide 24, the interface 23 (second emission surface) facing the interface 28 includes the flat portion 21 and the flat portion 21 formed in parallel or substantially parallel to the interface 28. The slanted portions 22 which are inclined at a constant angle in the same direction with respect to the?) Are alternately arranged. That is, the light guide 24 is formed in the step shape which goes down from the light source 26 in the cross section which makes the longitudinal direction of the light source 26 a normal line, as is evident from FIG.

The inclined portion 22 mainly serves as a surface that reflects light from the light source 26 toward the interface 28. On the other hand, the flat part 21 mainly acts as a surface which transmits the reflected light toward the observer side when the illumination light from the front light 20 returns as the reflected light from the liquid crystal cell 10.

Here, the shape of the light guide 24 will be described in more detail with reference to FIGS. 2A to 2C. 2A is a plan view of the light guide 24 viewed from above the normal direction of the flat portion 21, and FIG. 2B is a side view of the light guide 24 viewed from the normal direction of the incident surface 25, and FIG. 2C is a light guide 24. ) Is a cross-sectional view cut into a plane perpendicular to both the incident surface 25 and the interface 28.

The light guide 24 can be formed by injection molding using, for example, polymethylmetacrylate (PMMA). The light guide 24 which concerns on this embodiment has width W = 110.0mm, length L = 80. 0 mm, thickness h ₁ = 2 of incident surface 25 portion. 0 mm and the width w ₁ of the flat portion 21 = 1. It is set to 9 mm. Further, the width w ₂ of the inclined portion 22 is about 87 μm by setting the step height h ₂ = 50 μm of the inclined portion 22 and the inclination angle α = 30 ° of the inclined portion 22 with respect to the flat portion 21. .

Since the light guide 24 is formed in a staircase shape, the front light 20 has the following advantages. First, as shown in FIG. 2B, when the flat portion 21 is formed completely parallel to the interface 28 when viewed from the normal direction of the incident surface 25, the flat portion 21 is not visually recognized. Instead, only the inclined portion 22 is visually recognized. That is, the total sum of the projected projections from the inclined portion 22 to the incident surface 25 is equal to the incident surface 25.

In such a case, of the light source light incident from the incident surface 25, all of the components perpendicular to the incident surface 25 directly enter the inclined portion 22 and are reflected toward the interface 28. Accordingly, there is no problem that a large amount of light is emitted to the outside of the light guide from the surface opposite to the incident surface as seen in the conventional front light system described above. That is, the front light 20 is provided with the step-shaped light guide 24, and the utilization efficiency of light improves significantly compared with the conventional structure.

Next, the structure of the liquid crystal cell 10 and its manufacturing method are demonstrated.

As shown in FIG. 1, the liquid crystal cell 10 basically has a structure in which a pair of electrode substrates 11a and 11b sandwich the liquid crystal layer 12. As for the electrode substrate 11a, the transparent electrode 15a (scanning line) is provided on the glass substrate 14a which has light transmittance, and the liquid crystal aligning film 16a is formed so that this transparent electrode 15a may be covered.

The said glass substrate 14a is implement | achieved with the glass substrate (brand name: 7059) by Corning Corporation, for example. The transparent electrode 15a is made of, for example, indium tin oxide (ITO). The liquid crystal aligning film 16a is, for example, coated with an alignment film material (trade name: AL-4552) manufactured by Nippon Synthetic Rubber Co., Ltd. on a glass substrate 14a having a transparent electrode 15a formed thereon with a spin coater, and is used as an orientation treatment. It is created by performing a rubbing process.

Similarly to the electrode substrate 11a, the electrode substrate 11b is also produced by sequentially stacking the glass substrate 14b, the transparent electrode 15b, and the liquid crystal alignment film 16b. Moreover, an insulating film etc. can be formed with respect to the electrode substrate 11a * 11b as needed.

The electrode substrates 11a and 11b are arranged so that the liquid crystal aligning films 16a and 16b face each other, and the directions of the rubbing treatment are parallel and in the opposite directions (so-called antiparallel), and are bonded using an adhesive. At this time, between the electrode substrates 11a and 11b, glass gap spacers (not shown) having a particle diameter of 4.5 µm are previously dispersed, so that gaps are formed at uniform intervals.

The liquid crystal layer 12 is formed by introducing a liquid crystal into this gap by vacuum degassing. As the material of the liquid crystal layer 12, for example, a liquid crystal material (trade name: ZLI-3926) manufactured by Melk Corporation can be used. Moreover, (DELTA) n of this liquid crystal material is 0.02030. However, the liquid crystal material is not limited to this, and various liquid crystals can be used.

Moreover, the aluminum plate which performed the hairline process as the reflecting plate 17 is adhere | attached on the outer surface of the glass substrate 14b with an epoxy adhesive, for example. On the other hand, the polarizing plate 18 in which the polarization axis was set so that the outer surface of the glass substrate 14a may be 45 degrees with the orientation direction of the liquid crystal of the liquid crystal layer 12 is provided.

By the above process, the reflective liquid crystal cell 10 is manufactured. By combining the front light 20 with this liquid crystal cell 10 as follows, a reflective LCD having a front lighting device function is manufactured. First, the light guide 24 is laminated on the polarizing plate 18 of the liquid crystal cell 10. Moreover, the spacer (not shown) of 50 micrometers of particle diameters is previously scattered between the polarizing plate 18 and the light guide 24 of the liquid crystal cell 10. As a result, the gap 29 is formed to have a uniform thickness almost equal to the particle diameter of the spacer. That is, the interface 28 of the light guide 24 is optically equivalent to the interface of PMMA and the air layer. In addition, since the gap 29 has a thickness of about 100 times the wavelength of light, occurrence of interference or the like caused by the gap 29 is suppressed.

Next, a fluorescent tube is provided as the light source 26 so as to face the incident surface 25 of the light guide 24, and surrounds the light source 26 and the incident surface 25 with a reflecting mirror 27 (condensing means). All. The reflecting mirror 27 focuses light from the light source 26 only on the incident surface 25. As the reflection mirror 27, for example, an aluminum tape or the like can be used. By the above process, the reflective LCD provided with the front light 20 as auxiliary lighting is completed.

This reflective LCD can use the front light 20 in an illuminated mode when the ambient light is insufficient, and can use the front light 20 in the unlit reflection mode when sufficient ambient light is obtained.

Herein, the operation principle of the front light 20 will be described with reference to FIGS. 3A to 3C.

As described above, in the light guide 24, the total projected projection of the inclined portion 22 to the incident surface 25 is equal to the incident surface 25. For this reason, the component perpendicular | vertical to the incident surface 25 among the incident light from the light source 26 is reflected by the inclination part 22, as shown in FIG. 3A, and is shown in FIG. 3A from the interface 28. FIG. It is output toward the liquid crystal cell 10 which is not.

3B, among the incident light from the light source 26, the component which injects into the interface 23 is classified into two types by the behavior in the light guide 24. As shown in FIG. One is light which is incident and reflected directly on the inclined portion 22 and becomes the output light 31b to the liquid crystal cell 10, as in the light 31a shown in FIG. 3B. Second, like the light 32a shown in FIG. 3B, the light is propagated in the light guide 24 while totally reflecting between the flat portion 21 and the interface 28, and finally reaches the inclined portion 22 to reflect the light. It is the light used as the output light 32b.

In addition, as shown in FIG. 3C, among the incident light from the light source 26, the component incident on the interface 28 is totally reflected between the interface 28 and the flat portion 21 of the interface 23. It propagates inside the light guide 24, finally reaches and reflects the inclined portion 22, and is output from the interface 28 toward the liquid crystal cell 10.

As can be seen from the above description, almost all components of the incident light from the light source 26 to the light guide 24 are reflected by the inclined portion 22 and exit through the interface 28 to the liquid crystal cell 10. That is, the front light 20 of this embodiment is equipped with the light guide 24 which has the staircase interface 23, and the loss of the light from the light source 26 is very small, and the utilization efficiency of light source light is improved. .

Next, conditions 1. to 3. of the inclined portion 22 or the flat portion 21 for further improving the utilization efficiency of the light source light will be described.

1. About the inclined portion 22

In the light guide 24, the inclined portion 22 of the interface 23 mainly functions as a reflecting surface that reflects incident light from the light source 26. On the other hand, the flat part 21 of the interface 23 mainly functions as a transmissive surface which transmits the light reflected by the reflecting plate 17 provided in the back surface of the liquid crystal cell 10, and ambient light.

In order for the incident light from the light source 26 to totally reflect at the inclined portion 22, it is necessary to satisfy the following conditions. That is, light incident on the surface (interface) in contact with a material having a different refractive index is totally reflected at the interface when the incident angle is greater than or equal to the critical angle. For this reason, in order for the light incident on the inclined portion 22 to totally reflect at the inclined portion 22,

It may enter the inclined portion 22 at the incident angle θ ₁ .

However, in the above formula (2),

θ ₁ : incident angle to the inclined portion 22

n ₁ : refractive index of the light guide 24

n ₂ : refractive index of the material in contact with the light guide 24 in the inclined portion 22

θ _c : critical angle of the inclined portion 22

As described above, when the inclined portion 22 is formed such that the incident angle θ ₁ of the light to the inclined portion 22 satisfies Equation 2, the leakage of light from the inclined portion 22 to the outside of the light guide 24 is prevented. It can be suppressed and it can further improve the utilization efficiency of light.

2. About the flat part 21

Although it was stated above that the flat portion 21 mainly transmits light, as the light transmitted through the flat portion 21,

(A) reflected light from the liquid crystal cell 10,

(B) Ambient light when used in reflection mode

This exists.

The output light of (a) is dimmed in the liquid crystal layer 12 of the liquid crystal cell 10, is reflected by the reflecting plate 17, and again enters the light guide 24, and then exits from the interface 23 toward the observer side. At this time, mainly output from the flat part 21. The light reflected by the reflector 17 becomes diffused light. Since the diffused light is very rarely reflected by the flat portion 21, it is preferable that the diffused light enters the flat portion 21 at a critical angle or less. The critical angle changes with the refractive index of the light guide 24, but is generally around 42 degrees when PMMA is used as the material of the light guide 24. That is, it is preferable that the output light from the liquid crystal cell 10 is incident on the flat part 21 of the light guide 24 at about 40 degrees or less.

In addition, the flat part 21 does not necessarily need to be parallel to the interface 28. The incident angle into the flat part 21 also depends on the scattering range of the light in the reflecting plate 17. For this reason, considering the characteristics of the reflecting plate 17, as shown in FIG. 4, for example, the main range where light scatters in the reflecting plate 17 is ± 30 ° with respect to the normal of the reflecting plate 17. If the degree of inclination δ with respect to the reflecting plate 17 of the flat portion 21 is usually within ± 10 °, the component 33 of the light reflected by the flat portion 21 can be made very small. In addition, in FIG. 4, in order to make it easy to understand that the flat part 21 is inclined with respect to the interface 28, the inclination angle (delta) is shown larger than the above-mentioned preferable range.

Thus, when the flat part 21 is formed in parallel with respect to the interface 28 or the inclination within +/- 10 degrees, the incident light from the light source 26 will be a flat part with an incidence angle larger than the incidence angle to the inclined part 22. It enters (21). For this reason, the light which enters into the flat part 21 from the light source 26 hardly leaks to the outside, and the quantity of the light reflected by the flat part 21 increases. As a result, the loss of the light source light is suppressed.

In addition, a case where the present reflective LCD is used in the off light reflection mode is considered. At this time, in consideration of the ambient light in the case of using in the reflection mode of the above (b), the larger the area of the flat portion 21 is, the larger the area is preferable in order to reflect sufficient ambient light on the liquid crystal cell 10.

3. Arrangement of the inclined portion 22 and the flat portion 21 at the interface 23

About arrangement | positioning of the inclination part 22 and the flat part 21 of the interface 23,

(a) When the user views the reflective LCD from the interface 23 side, the area of the inclined portion 22 is small, and the area of the flat portion 21 is large,

(b) the total sum of the projected projections of the inclined portion 22 with respect to the incident surface 25 is large, and the sum of the projected projections of the flat portion 21 is small,

Two conditions are important.

The condition (a) above means that the total projected projection of the flat portion 21 to the interface 28 is larger than the total projected projection of the inclined portion 22. The size of the projected projection of the inclined portion 22 to the interface 28 is determined by the inclination angle α with respect to the interface 28 of the inclined portion 22 shown in FIG. 2C. Therefore, by adjusting the size of the inclination angle α, it is possible to make the area of the inclined portion 22 viewed from the user very small compared to the area of the flat portion 21.

In addition, the pitches of the inclined portion 22 and the flat portion 21 are excluded from the scan line of the liquid crystal cell 10 or matched with the bus line, so that the flat portion (the whole portion is actually displayed on the liquid crystal cell 10). 21) can be arranged, the light utilization efficiency is further improved.

As described above, in order to effectively use the incident light from the light source 26, the condition of (b) is only the inclined portion 22 of the interface 23 when the incident surface 25 is viewed from the normal direction. It means that it is preferable to be recognized.

Next, the measurement result of the illumination light intensity of the front light 20 is demonstrated. In order to measure the illumination light intensity of the front light 20, a measuring system as shown in FIG. 5 was used. That is, the normal direction of the interface 28 of the front light 20 was made into 0 degree, and the light intensity in the range of 0 degrees to +/- 90 degrees was measured with the detector 34. As shown in FIG.

This result is shown in FIG. As is apparent from FIG. 6, in the front light 20, light incident from the light source 26 to the light guide 24 through the incident surface 25 is generated by the action of the light guide 24. It can be seen that 28 is almost emitted in the normal direction. That is, the front light 20 can enter light from the light source 26 disposed on the side of the light guide 24 almost perpendicularly to the liquid crystal cell 10, thus functioning as bright auxiliary illumination.

In addition, the reflective LCD of the present embodiment has an advantage that brighter display is possible as compared with a self-luminous display such as a transmissive LCD, a CRT, or a PDP.

That is, as shown in FIG. 7A, the light 36a from the self-luminous display 35 is reversed in the advancing direction with respect to the ambient light 37. For this reason, the component 36b which subtracted the ambient light 37 from the light 36a is recognized by an observer.

In contrast, in the reflective LCD of the present embodiment, when used in the illumination mode, as shown in FIG. 7B, the auxiliary light 39a from the front light 20 and the ambient light 37 form the liquid crystal cell 10. Is reflected by a reflector (not shown), and the component 39b corresponding to the sum of the auxiliary light 39a and the ambient light 37 is recognized by the viewer. Accordingly, brighter displays are realized not only in dark places but also in bright places such as outdoors during the day.

Thus, in the structure which concerns on this embodiment, as the front light 20 is equipped with the step-shaped light guide 24, the utilization efficiency of the light radiate | emitted from the light source 26 is improving. As a result, sufficient illumination light can be provided to the liquid crystal cell 10 when there is not enough ambient light, and it becomes possible to provide a reflective LCD which can always display bright regardless of the surrounding environment.

As described above, the front lighting apparatus according to the present invention includes a light source and a light guide, the front lighting apparatus used to be disposed in front of the light to be used, the incident surface to which the light guide is incident light from the light source, and the object to be illuminated A first emission surface that emits light toward the second emission surface, and a second emission surface that emits reflected light from an object to be illuminated opposite the first emission surface, wherein the second emission surface mainly includes light from a light source; The inclination part which reflects toward 1 exit surface and the flat part which mainly transmits the reflected light from the to-be-illuminated object are formed in the staircase shape alternately arrange | positioned.

Therefore, in the above-described configuration, the illumination light is emitted from the first emission surface to the illuminated object, and the reflected light from the illuminated object is returned from the first emission surface back into the light guide to pass through the flat portion of the second emission surface. Reach the observer's side. In the light guide member having the above-described configuration, the second emission surface facing the first emission surface is formed in a step shape in which the inclined portion and the flat portion are alternately arranged, and the inclined portion located between the flat portion and the flat portion is mainly a light source. Since the light from the light is reflected toward the first emission surface, all of the components parallel to the flat portion of the light incident from the light source are reflected at the inclined portion and irradiated to the illuminated object from the first emission surface. Therefore, compared with the conventional structure which has a light guide body formed in substantially flat form, the light component which advances parallel to a flat part does not leak out of the light guide body, but is irradiated with a to-be-illuminated object in the front illumination apparatus of this invention. Therefore, the utilization efficiency of the light source light can be improved to provide a brighter front lighting device.

The above constitution includes a light source and a light guide, wherein the light guide includes a planar bottom surface, a surface opposing the bottom surface, and light from a light source. It is also possible to express that the incidence surface having an incident surface is formed, and the surface is formed in a step shape in which a flat portion substantially parallel to the bottom surface and an inclined portion inclined in the same direction with respect to the flat portion are alternately arranged.

In the front lighting apparatus according to the present invention, in the above configuration, the incident surface is present on the side of the light guide. Therefore, there is an advantage that the light source is not directly seen from the observer because light is incident from the side surface of the light guide. This realizes a front lighting device in which a direct light from the light source does not affect the image of the object to be illuminated and a clear image of the object to be obtained is obtained.

In the front lighting apparatus according to the present invention, in the above configuration, the total projected projection of the inclined portion in the plane perpendicular to the first exit surface becomes almost equal to the total projected projection of the incident surface in the plane. have. Therefore, of the light incident from the incident surface of the light guide, all of the components parallel to the first emission surface enter the inclined portion and reflect toward the first emission surface. As a result, the utilization efficiency of the light source light is further improved to provide a brighter front lighting device.

In the above configuration, the front lighting apparatus according to the present invention further includes a light collecting means for injecting light from the light source only to the incident surface. Therefore, since the loss of the light source light can be reduced, the utilization efficiency of the light source light is further improved, and the front lighting device as a brighter surface light source is realized.

In the front lighting apparatus which concerns on this invention, in the said structure, the sum total of the projection projected to the said 1st exit surface of the said inclination part is smaller than the sum total of the projection projected to the said 1st exit surface of the said flat part. . Since the reflected light from the object to be incident on the first emission surface passes through the flat portion on the second emission surface and exits to the observer side, in order to obtain a bright and clear image, the total of the projected projections of the inclined portion exits the flat portion. It is desirable to be much smaller than the sum of. Therefore, according to the above configuration, the area of the flat portion mainly contributing to the display of the image of the object to be illuminated increases in appearance. As a result, a front lighting apparatus in which a bright and clear image is obtained is realized.

In the front lighting apparatus which concerns on this invention, in the said structure, the said flat part has the inclination angle of 10 degrees or less with respect to the said 1st exit surface, or parallel with the said 1st exit surface. In particular, in consideration of the influence on the display quality of the image of the object to be illuminated, it is preferable to set the inclination angle of the flat portion on the second exit surface to the first exit surface in the range of 0 to 10 degrees.

The front lighting apparatus according to the present invention satisfies Equation 2 in the above configuration. This is because the light incident on the inclined portion of the second emission surface from the light source is preferably totally reflected at this inclination, so that the incident light on the inclined portion is totally reflected when the incident angle θ ₁ on the inclined portion satisfies the above condition. As a result, the light from the light source does not leak from the inclined portion to the observer side, and the light utilization efficiency is further improved. As a result, a front lighting device functioning as a bright surface light source is realized.

The reflection type liquid crystal display device according to the present invention includes a reflection type liquid crystal element having a reflection plate, and a front illumination device having the above configuration is disposed on the front surface of the reflection type liquid crystal element.

As a result, when there is a sufficient amount of ambient light, for example, outdoors in the middle of the day, the front lighting device can be used in an unlit state, and when the sufficient amount of ambient light cannot be obtained, the front lighting device can be turned on and used. As a result, it becomes possible to provide a reflective liquid crystal display device capable of realizing always bright high quality display regardless of the surrounding environment.

In the reflective liquid crystal display device according to the present invention, the reflective liquid crystal element includes a scanning line, and the pitch of the scanning line and the pitch of the flat portion on the second exit surface of the front lighting apparatus are substantially the same. It is preferable that the flat portion is arranged above the scanning line. Thereby, the flat part can be arrange | positioned on the pixel area where display is actually performed by a liquid crystal element. As a result, since the reflected light from the pixel region enters the flat portion without waste, it becomes possible to provide a reflective liquid crystal display device that can further improve the utilization efficiency of light and realize high quality display.

[Embodiment 2]

Other embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is written together in the structure which has a function similar to the structure demonstrated in Embodiment 1 mentioned above, and the description is abbreviate | omitted.

As shown in FIG. 8, the reflective LCD according to the present embodiment includes the front light 20 (first light guide) described in Embodiment 1 and a wedge-shaped second light guide on the front surface of the liquid crystal cell 10. A front light system 51 constituted by 40 is provided.

The second light guide 40 is disposed between the light guide 24 of the front light 20 and the liquid crystal cell 10, and has a slope 41 parallel to the interface 28 of the light guide 24. And a bottom face 42 parallel to the surface of the liquid crystal cell 10. As shown in FIG. 9A, the inclination angle of the slope 41 with respect to the bottom 42 is a portion where the inclined portion 22 and the flat portion 21 are in contact with the ridge in the interface 23 of the light guide 24. It is preferable to design so that the line 49 which mutually connects (2) may become parallel with the bottom face 42. FIG.

In addition, the second light guide 40 is preferably formed of a material having at least the same refractive index as the light guide 24 that is the first light guide. Of course, the second light guide 40 may be formed of the same material as the light guide 24. In addition, when the light guide 24 and the second light guide 40 are formed to be integrally formed by, for example, injection molding, the manufacturing process can be simplified.

In the gap between the light guide 24 and the second light guide 40, a spacer (not shown) having a particle diameter of 50 μm is dispersed in advance. As a result, a gap 43 substantially equal to the particle diameter of the spacer is formed in the gap between the light guide 24 and the second light guide 40.

Between the bottom face 42 of the 2nd light guide 40 and the polarizing plate 18 of the liquid crystal cell 10, it is filled with the filler (not shown) which makes the refractive index of both match. As a result, attenuation of light due to reflection at the interface between the second light guide 40 and the polarizing plate 18 is prevented, and the loss of the light source light is further suppressed. Moreover, as said filler, UV curable resin, methyl salicylate, etc. can be used, for example.

Here, an effect of providing the second light guide 40 between the light guide 24 and the liquid crystal cell 10 will be described.

As shown in FIG. 9B, in the configuration (Embodiment 1) in which the second light guide 40 is not provided, from the inclined portion 22 to the interface 28 as the emission surface to the liquid crystal cell 10. The distance l _n becomes smaller as the distance X _n from the light source 26 becomes larger. On the other hand, in the front light system 51 of this embodiment, as shown in FIG. 9A, by providing the 2nd light guide 40, it is an exit surface from the inclination part 22 to the liquid crystal cell 10. FIG. The distance l _n to the bottom face 42 of the second light guide 40 is substantially the same regardless of the distance x _n from the light source 26.

That is, the second light guide 40 serves to make the distance from the inclined portion 22 of the front light 20 to the liquid crystal cell 10 to be constant, whereby the front light system 51 causes the light source 26 to be light source 26. It serves as a surface light source for emitting light at a constant luminance regardless of the distance from

Here, in order to confirm the effect by the 2nd light guide 40, as shown in FIG. 10A, moving the detector 44 in parallel with the bottom face 42 of the 2nd light guide 40, The luminance distribution of the output light of the front light system 51 was measured. Moreover, the vicinity of the incident surface 25 was made into the measurement start position P _S, and the position farthest from the light source 26 in the bottom face 42 was made into the measurement end position P _E. The result of the measurement is as shown in FIG. 11A.

Similarly, for comparison, in order to measure the luminance distribution of the output light of the configuration (Embodiment 1) in which the second light guide 40 is not provided, as shown in FIG. The measurement was performed while moving parallel to the interface 28 of 20). Moreover, the vicinity of the incident surface 26 was made into the measurement start position P _S , and the position farthest from the light source 26 in the interface 28 was made into the measurement end position P _E. The measurement result is as showing in FIG. 11B.

As apparent from comparing FIGS. 11A and 11B, when the second light guide 40 is not provided, as shown in FIG. 11B, the pitch p of the peak of luminance is close to the light source 26. As the front light system 51 of the present embodiment is smaller as it is larger and smaller as it moves away from the light source 26, as shown in FIG. 11A, the pitch p of the peak of the luminance is lower than the bottom surface of the second light guide 40 ( 42) Almost the same throughout, and the same peak of luminance.

As described above, the reflective LCD of the present embodiment includes a front light system 51 on the front surface of the liquid crystal cell 10, and the front light system 51 includes the light guide 24 serving as the first light guide and a liquid crystal. By providing a second light guide 40 between the cells 10 to make the distance from the inclined portion 22 of the light guide 24 to the liquid crystal cell 10 constant, the front light system 51 Even when the liquid crystal cell 10 is illuminated without spots and sufficient ambient light is not obtained, a high quality display without bright spots is achieved.

As described above, the front lighting apparatus according to the present invention further includes a second light guide for uniformizing the luminance distribution of the emitted light from the first emission surface when the light guide according to the first embodiment is the first light guide. Configuration.

In the front lighting apparatus of the present invention, since the first light guide is formed in a step shape, the distance from the inclined portion of the second emission surface to the first emission surface is reduced in proportion to the distance from the light source. For this reason, the luminance distribution of light emitted from the first emission surface may not be uniform. The above structure includes the second light guide member, whereby the luminance distribution of the emitted light to the object to be illuminated is made uniform. As a result, it is possible to provide a front illumination device that functions as a surface light source without luminance unevenness.

In the front lighting apparatus according to the present invention, in the above-described configuration, the second light guide is disposed on the first surface facing the first exit surface of the first light guide, and the first surface is opposed to the first surface. The first surface and the second surface are provided from the respective inclined portions on the second exit surface of the first light guide, while having a second surface for emitting light incident through the first surface to the object to be illuminated. It is formed so that the distance to a 2nd surface may become substantially uniform.

Therefore, in the above configuration, by providing the second light guide member, the second light guide member is used as the emission surface from the inclined portion of the second emission surface on which the light from the light source is reflected in the first light guide to the object to be illuminated. The distance to the second surface is equalized, and the luminance distribution of the emitted light from the second surface is averaged. As a result, a front lighting device functioning as a surface light source without luminance unevenness is realized.

In the front lighting apparatus according to the present invention, it is preferable that the refractive index of the first light guide and the refractive index of the second light guide are substantially equal in the above-described configuration. In this configuration, the refractive index of the first light guide is substantially equal to that of the second light guide, so that the light reflected from the inclined portion of the second slope in the first light guide is emitted toward the object at the same angle. do. As a result, it is not necessary to consider the change in the trajectory of the light due to the refraction upon incidence on the second light guide or upon exit from the second light guide, so that the design becomes easy.

In the front lighting apparatus which concerns on this invention, the 1st light guide body and the 2nd light guide body may be integrally formed in the said structure. In this structure, since the 1st light guide and the 2nd light guide are integrally formed, there exists an advantage that manufacture is easy.

In the front lighting apparatus according to the present invention, in the above-described configuration, a filler is introduced between the first light guide and the second light guide to mitigate the difference in refractive index at the optical interface existing between these light guides.

According to the above configuration, the attenuation of the light due to reflection at the optical interface existing between the first and second light guides is suppressed as compared with the case where an air layer exists between the first and second light guides. do. As a result, the utilization efficiency of the light source light is further improved, and the front lighting device as a brighter surface light source is realized. Moreover, when the refractive index of at least one of a 1st light guide and a 2nd light guide and a refractive index of a filler are equal, the number of the optical interfaces between a 1st light guide and a 2nd light guide can be reduced, and it is more effective.

[Embodiment 3]

Another embodiment of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the structure which has a function similar to the structure demonstrated by each above-mentioned embodiment, and the description is abbreviate | omitted.

In the reflective LCD of the present embodiment, as shown in FIG. 12, the front light system 52 constituted by the front light 20 and the second light guide 45 is disposed on the front surface of the liquid crystal cell 10. Configuration.

As shown in FIG. 13, the second light guide 45 is a forward scattering plate having a function of scattering incident light from the light guide 24 only toward the traveling direction, and is incident from a predetermined angle range. It is an anisotropic scattering plate having the property of scattering only light and transmitting incident light from the above-described predetermined angle range. As the 2nd light guide 45 which satisfy | fills such conditions, the visual control panel (brand name: Lumisty) etc. of Sumitomo Chemical Co., Ltd. can be obtained as a commercial item, for example.

Moreover, it is preferable that the angle range in which the 2nd light guide 45 scatters incident light fully includes the angle range in which the emitted light from the light guide 24 is incident. Thereby, the emitted light from the light guide 24 can be scattered without waste, and the utilization efficiency of light source light can be improved. Further, since the second light guide 45 scatters only light incident from a predetermined angle range and transmits incident light from outside the predetermined angle range, incident light from outside the predetermined angle range is incident. Since the second light guide 45 does not work, deterioration of display quality due to unnecessary scattered light is prevented.

In the gap between the light guide 24 and the second light guide 45, a spacer (not shown) having a particle diameter of 50 μm is dispersed in advance. As a result, as shown in FIG. 12, a gap 46 substantially equal to the particle diameter of the spacer is formed in the gap between the light guide 24 and the second light guide 45.

Between the second light guide 45 and the polarizing plate (not shown) of the liquid crystal cell 10, it is filled with the filler (not shown) which makes the refractive index of both match. As a result, attenuation of light due to reflection at the interface between the second light guide 45 and the liquid crystal cell 10 is prevented, and the loss of the light source light is further suppressed.

Here, the measurement result of the illumination light intensity of the front light system 52 is demonstrated. In order to measure the illumination light intensity of the front light system 52, the measurement system similar to the measurement system (refer FIG. 5) used in Embodiment 1 mentioned above was used. Here, the normal direction of the second light guide 45 of the front light system 52 is set to 0 °, and the liquid crystal cell 10 side of the second light guide 45 is in a range of 0 ° to ± 90 °. The light intensity from the surface located at was measured by the detector 34. The measurement result is shown in FIG.

As is apparent from FIG. 14, the front light system 52 of the present embodiment is compared with the first embodiment because the light emitted from the light guide 24 as the first light guide is scattered by the second light guide 45. Thus, it can be seen that it has a flat angle characteristic.

Thus, the structure demonstrated by this embodiment is equipped with the 2nd light guide 45 which scatters the light emitted from the light guide 24, and the luminance distribution of the light radiate | emitted to the liquid crystal cell 10 is averaged, and a liquid crystal It is possible to irradiate the cell 10 without spots.

As the second light guide 45, a hologram or the like can be used in addition to the anisotropic scattering plate.

As mentioned above, the front light-emitting device which concerns on this invention may be a structure which the 2nd light guide body shown in Embodiment 2 is a light scattering body which scatters the light emitted from the 1st light emission surface in a 1st light guide body.

In the above configuration, the light scattering body as the second light guide scatters the light emitted from the first light guide, so that the luminance distribution of the light emitted to the object to be illuminated is averaged. As a result, a front lighting device functioning as a surface light source without luminance unevenness is realized.

The front lighting apparatus according to the present invention is an anisotropic scattering body in which the light scattering body scatters only light incident from a predetermined angle range, and the angle range in which the light emitted from the first light guide is incident on the second light guide. At least part of is included in the predetermined angle range.

Therefore, according to the above-described configuration, the anisotropic scattering body as the light scattering body does not act on incident light outside the predetermined angle range, such as the light output in the direction of the observer, for example. The deterioration of phase is suppressed. Further, the incident light can be efficiently scattered by the incident light from the first light guide in the angle range of the incident light scattered by the light scattering body as the second light guide. As a result, the front lighting apparatus which does not have luminance unevenness and functions as a bright surface light source, and obtains a clear image of the object to be illuminated is realized.

In the front lighting apparatus according to the present invention, in the above configuration, the light scattering body is also a front scattering body. That is, since the light scatterer serving as the second light guide is a front scatterer that scatters light incident from the first light guide only toward the direction of travel of the light, there is no backscattering of the light incident from the first light guide. Thereby, while the utilization efficiency of light is further improved, the image of a to-be-illuminated object is prevented from being deteriorated by backscattered light. As a result, the front lighting apparatus which realizes a clear image without a brightness unevenness and functions as a bright surface light source, and is obtained with a to-be-illuminated object is realized.

[Embodiment 4]

Another embodiment of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the structure which has a function similar to the structure demonstrated by each above-mentioned embodiment, and the description is abbreviate | omitted.

As described in Embodiment 1 described above, when the interface 23 on the observer side of the light guide 24 is formed by the inclined portion 22 and the flat portion 21, the liquid crystal cell 10 reflects it. When the light incident on the light guide 24 again passes through the interface 23, blurring or blurring of the image may occur.

That is, as shown in FIG. 15, the output light 48a from the liquid crystal cell 10 does not necessarily transmit not only the flat part 21 but also the inclination part 22 to the observer side. At this time, when the outgoing light 48b from the inclined portion 22 and the outgoing light 48c from the flat portion 21 are emitted in different directions and intersect, bleeding or blur appear on the image to be displayed. There is.

In order to solve such a problem, as shown in FIG. 16, the reflective LCD of the present embodiment is a metal that reflects light on the surface of the inclined portion 22 at the interface 23 of the light guide 24. It is the structure to which the reflective film 47 was added. As shown in FIG. 16, the metal reflective film 47 reflects all of the light incident on the inclined portion 22 irrespective of the incident angle. As a result, the light emitted from the interface 23 to the observer side becomes only light transmitted through the flat part 21. As a result, a clear display image without blurring or blurring can be obtained.

Below, an example of the method of manufacturing the said metal reflection film 47 is demonstrated using aluminum as an example. In addition, the material of the metal reflection film 47 is not limited to aluminum, For example, metal, such as silver, can also be used.

First, as shown in FIG. 17A, the aluminum film 61 is formed by sputtering on the entire surface of the interface 23 of the light guide 24. In addition, as shown in FIG. 17B, a photoresist 62 is applied to the surface of the aluminum film 61. Next, through the exposure process, as shown in Fig. 17C, the photoresist 62 is patterned. As shown in FIG. 17D, the aluminum film 61 is etched using the patterned photoresist 62 as a mask. After that, the photoresist 62 is peeled off, so that the metal reflective film 47 made of aluminum is formed on the surface of the inclined portion 22 of the interface 23 as shown in FIG. 17E.

As described above, by providing the metal reflective film 47 on the surface of the inclined portion 22, as shown in FIG. 16, the inclination angle α of the inclined portion 22 with respect to the flat portion 21 can be large. . For example, as shown in FIG. 18, in the structure in which the metal reflective film 47 is not provided in the inclined part 22, when the inclination angle (alpha) is made large at 60 degrees, the inclined part at incidence angle smaller than the critical angle (theta) _c . The light 49a incident on the 22 becomes the light 49b passing through the inclined portion 22 and transmitted to the observer side. Such light 49b is not preferable because it degrades the display quality.

On the other hand, in the structure of this embodiment, when the metal reflection film 47 is formed in the inclination part 22, even if the inclination angle (alpha) is taken large, it passes through the inclination part 22 like the light 49b mentioned above. Light does not exist, and all the light is reflected by the inclined portion 22.

As described above, as the inclination angle α of the inclined portion 22 can be large, the inclined portion 22 becomes difficult to be visualized when viewed from the normal direction of the flat portion 21, so that the display quality can be improved. There is an advantage that can be.

In addition, as shown in FIG. 19, when the black matrix 47b (shielding member) which prevents reflection of ambient light is laminated on the surface of the metal reflective film 47, it is possible to prevent the ambient light from being reflected toward the observer side. . This is more preferable because deterioration of display quality due to reflection of ambient light toward the observer side is prevented.

As described above, the front light 20 according to the present embodiment is characterized in that the metal reflective film 47 for removing the transmitted light from the inclined portion 22 to the observer's side is formed in the inclined portion 22. Accordingly, since the light emitted from the interface 23 to the observer side becomes only the light emitted from the flat portion 21, in the reflective LCD provided with the front light 20 on the front surface of the liquid crystal cell 10, It is possible to obtain a clear display image without blurring or blurring.

As mentioned above, the front lighting apparatus which concerns on this invention is a structure in which the reflection member which reflects light is provided in the surface of the inclined part of a 1st light guide. It is preferable that the light incident on the inclined portion of the second emission surface from the light source is totally reflected at this inclined portion. Therefore, by providing the reflecting member in the inclined portion, the incident light to the inclined portion is totally reflected regardless of the incident angle. Thereby, the light from a light source does not leak from an inclination part to an observer side, and the utilization efficiency of light further improves. As a result, a front lighting device functioning as a bright surface light source is realized.

In the front lighting apparatus which concerns on this invention, the light shielding member is provided in the surface of the said reflection member in the said structure. Therefore, it is possible to provide a front illumination device in which ambient light is reflected from the reflecting member to enter the observer's eye, preventing deterioration of the display quality of the image of the object to be illuminated, and a clear image of the object to be obtained.

In the above configuration, when the inclined portion of the front lighting apparatus according to the present invention has the refractive index of the light guide member as n ₂ and the refractive index of the external medium contacting the inclined portion as n ₁ , the incident angle θ of light incident from the light source to the inclined portion is It works effectively in the range of inequalities.

θ <arcsin (n ₁ / n ₂ )

The incident angle θ of light incident from the light source to the inclined portion becomes smaller as the inclination angle of the inclined portion relative to the flat portion becomes larger. When the reflective member is provided on the inclined portion of the second emission surface, the incident light on the inclined portion is totally reflected regardless of the incidence angle, and is not transmitted through the inclined portion to the observer's side. Thereby, it becomes possible to design the inclination-angle of the inclination part with respect to the flat part largely so that the incidence angle (theta) of the light which injects into a inclination part from a light source may satisfy said inequality. As a result, when viewed from the normal direction of the flat portion, the inclined portion that does not contribute to the display of the image of the object to be visualized becomes difficult to be visualized, thereby improving the display quality of the image of the object to be illuminated.

[Embodiment 5]

Another embodiment of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the structure which has a function similar to the structure demonstrated by each above-mentioned embodiment, and the description is abbreviate | omitted.

In the reflective LCD according to the present embodiment, as shown in FIG. 20, the front light 20 described in the first embodiment and the interface 23 of the front light 20 are formed on the front surface of the liquid crystal cell 10. And a front light system 53 constituted by an optical compensating plate 64 (compensation means) provided at the.

In the optical compensating plate 64, the bottom face 64a, which is a surface facing the light guide 24 of the front light 20, has an interface 23 of the light guide 24 as shown in FIG. 20. Complementary staircase shape. That is, in the bottom face 64a, the inclined portion 65 parallel to the inclined portion 22 is formed at a position facing the inclined portion 22 of the light guide 24, and the flat portion of the light guide 24 is formed. At a position opposite to 21, a flat portion 66 parallel to the flat portion 21 is formed. On the other hand, in the optical compensation plate 64, the surface 64b which is a surface located on the observer side is formed as a plane parallel to the interface 28 of the light guide 24.

Similar to the light guide 24, the optical compensation plate 64 can be created by injection molding using PMMA, for example. As described above, the optical compensation plate 64 and the light guide 24 are disposed so as to face each of the inclined portions and the flat portions, and are bonded through a spacer (not shown) having a particle diameter of about 20 mu m. As a result, an air layer 67 having a substantially uniform thickness is interposed between the bottom face 64a of the optical compensating plate 64 and the interface 23 of the light guide 24.

In this way, the optical compensation plate 64 is provided on the front surface of the light guide 24, and the air layer 67 is present between the light guide 24 and the optical compensation plate 64, thereby obtaining the following effects. .

That is, as described above with reference to FIG. 15 in the fourth embodiment, the light 48a · 48a which is incident again from the liquid crystal cell 10 into the light guide 24 is in the same direction inside the light guide 24. Even if it advances, by penetrating the inclination part 22 or the flat part 21 of the interface 23, respectively, it will exit | emit from the interface 23 of the light guide body in a mutually different direction, and cause the image to blur or blur.

On the other hand, in the front light system 53 of this embodiment, as shown in FIG. 21, the light 68a * 69a which entered the light guide 24 from the liquid crystal cell 10 in the same direction is guided. After exiting from (24), the light is advanced in the same direction by refracting at the bottom face 64a serving as an interface between the air layer 67 and the optical compensating plate 64, as shown by the light 68b and 69b. And exit in the same direction from the surface 64b of the optical compensating plate 64. As a result, when viewed from the observer's side, a clear image without blurring or blurring is obtained.

In addition to the optical compensation plate 64 described above, as shown in FIG. 22A, the optical compensation plate 71 formed on the flat plate may be disposed on the front surface of the light guide 24. In this case, as shown in FIG. 22B, the optical compensating plate 71 includes a region 71a into which light emitted from the inclined portion 22 of the light guide 24 is incident and the flatness of the light guide 24. Since the region 71b into which the light emitted from the section 21 enters has different refractive indices, the emission angle θ _a · θ _b of the light from each surface of the regions 71a and 71b to the observer side is substantially reduced. Becomes the same. Alternatively, the region 71a may be formed of a member having a diffraction function (for example, a diffraction element) in order to diffract the light passing through the region 71a in the same direction as the light passing through the region 71b. have.

Alternatively, as shown in FIG. 22C, in the optical compensation plate 71, a region in which light emitted from the inclined portion 22 of the light guide 24 enters is used as the black mask 71c that blocks the light. By forming, it is possible to prevent the light emitted from the inclined portion 22 from reaching the observer's side.

Thus, according to the structure of this embodiment, each of the inclination part 22 and the flat part 21 of the interface 23 of the light guide 24 by the optical compensation plate 64 or the optical compensation plate 71 is performed. By aligning the light emission direction from the light source, a reflective LCD capable of clear display without blurring or blurring is realized.

As described above, the front lighting apparatus according to the present invention is further configured to include compensation means for matching the exiting direction of the exiting light from the flat part and the exiting light from the inclined part in the above-described configuration.

Since the second emission surface is formed in a step shape in which the flat portion and the inclined portion are alternately arranged, the reflected light from the illuminated object incident on the light guide from the first emission surface is respectively the flat portion and the inclined portion of the second emission surface. There is a possibility of emitting from the mutually different direction from the other, causing blur or blur of the image of the object to be illuminated. For this reason, by providing the compensation means which matched the emission direction from the light emission from the flat part of the 2nd exit surface and the light exit from the inclination part like the said structure, it becomes possible to obtain a clear image of a to-be-illuminated object.

In the above-described configuration, the front lighting apparatus according to the present invention has the compensating means, wherein the compensating means includes a first surface facing the second exit surface of the light guide and a second surface facing the first surface. The first surface of the light guide is alternately arranged with an inclined surface substantially parallel to the inclined portion of the second emission surface and a flat surface substantially parallel with the flat portion of the second emission surface, and is complementary to the second output surface. And a second surface of the compensating means is disposed substantially parallel to the first exit surface of the light guide.

Therefore, according to the above configuration, the light emitted from the first exit surface of the light guide toward the object to be illuminated is reflected by the light object and returns to the inside of the light guide from the first exit surface again, as shown in FIG. 21. As described above, the light exits in different directions from each of the flat portion 21 and the inclined portion 22 of the second emission surface. Here, the first surface 64a of the compensating means 64 disposed at a position opposite to the second emission surface is formed in a step shape complementary to the second emission surface of the light guide, whereby the flat portion 21 The light 69a exiting from) enters the flat surface of the first surface of the compensating means, and the light 68a exiting from the inclined portion 22 enters the inclined surface of the first surface and exits in substantially the same direction. It becomes light 68b * 69b and it exits from a 2nd surface. In this way, as the emission direction of the emission light from the flat portion and the emission direction of the emission light from the inclined portion are aligned, it becomes possible to obtain a clear illuminated object image without blurring or blurring.

In the above-described configuration, the front lighting apparatus according to the present invention includes, in the compensation means, an area in which the outgoing light from the inclined portion of the second exit surface is incident, and outgoing light from the flat portion of the second exit surface. The incident areas have different refractive indices.

Therefore, in the above-described configuration, the area where the light emitted from the inclined portion mainly enters, and the area where the light emitted mainly from the flat portion enters, respectively from the inclined portion and the flat portion by means of compensation having different refractive indices. The exit direction of is aligned. As a result, it becomes possible to provide a front illumination device in which a clear illuminated object image without blurring or blurring is obtained.

In the above-described configuration, the front lighting apparatus according to the present invention may include, in the compensation means, a diffraction element may be provided in a region where mainly the light emitted from the inclined portion of the second emission surface is incident. In this configuration, as the diffraction element is mainly provided in the region where the light emitted from the inclined portion is incident, the emission direction from each of the inclined portion and the flat portion is aligned. As a result, a front lighting apparatus is obtained in which a clear illuminated object image without blurring or blurring is obtained.

In the above-described configuration, the front lighting apparatus according to the present invention may include, in the compensation means, a light shielding member in a region where mainly the light emitted from the inclined portion of the second emission surface is incident. In this structure, as the light shielding member which does not transmit light is provided in the area | region which mainly the light emitted from the inclination part injects, the light radiate | emitted from the 2nd output surface of a light guide will become only the light emitted from the flat part. . Thereby, the front lighting apparatus which obtains the clear to-be-illuminated object image without bleeding or blur is realized.

[Embodiment 6]

Another embodiment of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the structure which has a function similar to the structure demonstrated by each above-mentioned embodiment, and the description is abbreviate | omitted.

The reflective LCD according to the present embodiment adds a touch panel function to the front light system 53 (see Fig. 20) of the reflective LCD described in the fifth embodiment.

In order to realize the above touch panel function, as shown in FIG. 23, the reflective LCD of the present embodiment uses a transparent electrode 72 made of, for example, ITO, on the bottom face 64a of the optical compensating plate 64. In addition, the inclined portion 22 of the light guide 24 is provided with a reflective electrode 73 made of a material that reflects light and is conductive, such as aluminum. The transparent electrode 72 and the reflective electrode 73 constitute position detection means.

24 is a plan view showing the shape of the reflective electrode 73 when viewed from the normal direction of the flat portion 21 of the light guide 24. As shown in FIG. 24, since the reflective electrode 73 is provided on the front surface of the inclined portion 22 of the light guide 23, the reflective electrode 73 is striped when viewed from the normal direction of the flat portion 21 of the light guide 24. to be. In addition, as shown in FIG. 25, the transparent electrode 72 formed on the optical compensating plate 64 is formed in a stripe shape, and the reflective electrode 73 and the transparent electrode 72 are orthogonal to each other to form a matrix.

Moreover, between the reflective electrode 73 of the light guide 24 and the transparent electrode 72 of the optical compensation plate 64, the plastic bead spacer (not shown) of about 10 micrometers of particle diameters is spread | dispersed, and this particle | grain is scattered, A gap about the same size as the diameter is formed.

This optical compensating plate 64 is flexible, and as shown in FIG. 26, the transparent electrode 72 and the reflective electrode 73 come into contact with each other by pressing the pen 74. Recognition of the coordinates pressed by the pen 74 is performed as follows. As shown in FIG. 25, by scanning a signal in a line sequence to each of the transparent electrode 72 and the reflective electrode 73, the X coordinate and Y coordinate of the contact point 75 are detected, and it is in the plane of a touch panel. The coordinates of the position pressed by the pen 74 can be specified.

Although the structure in which the stripe-shaped transparent electrode 72 is formed on the optical compensation plate 64 has been described as an example, the transparent electrode may be formed on the entire surface of the bottom face 64a of the optical compensation plate 64. However, as described above, the transparent electrode 72 formed in a stripe form has the advantage that the light utilization efficiency is high.

Thus, according to the structure of this embodiment, since the optical compensation plate 64 functions as a touch panel, it becomes possible to provide the reflective LCD which can input pens with respect to the content displayed on the liquid crystal cell 10. FIG.

As described above, the reflection type liquid crystal display device according to the present invention is a reflection type liquid crystal display device having the front illumination device shown in the fifth embodiment on the front surface of the reflection type liquid crystal element having the reflection plate, wherein the compensation means is predetermined. While having flexibility with respect to pressure, a pair of position detection means for detecting the position where pressure is applied by contacting each other is provided in each of the compensation means and the second exit surface.

Therefore, in the above structure, the front lighting device functions as a so-called touch panel. That is, when a certain position on the surface of the compensation means is pressed, for example by a pen or the like, as the compensation means is bent, the pair of position detection means respectively provided on the compensation means and the second exit surface contact each other at the above positions. When this position detection means recognizes this position as a coordinate, the reflection type liquid crystal display device with which pen input is possible with respect to the content displayed on the liquid crystal element is implement | achieved.

In the reflective liquid crystal display device according to the present invention, the reflective liquid crystal element includes a scanning line, and the position detecting means includes a transparent electrode formed on a flat portion of the second emission surface. The transparent electrode is arrange | positioned above the scanning line so that the pitch and the pitch of the said transparent electrode are substantially the same.

Therefore, in the above structure, the transparent electrode of the position detection means can be arranged on the pixel region where display is actually performed by the liquid crystal element. As a result, the resolution of the touch panel and the resolution of the liquid crystal element are almost the same. Thereby, there exists an effect that the unity of an input image and a display image improves at the time of inputting by a touchscreen.

[Embodiment 7]

Another embodiment of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the structure which has a function similar to the structure demonstrated by each above-mentioned embodiment, and the description is abbreviate | omitted.

As shown in FIG. 27, the front light provided with the reflective LCD according to the present embodiment further includes the incident surface 25 of the light source 26 and the light guide 24, in addition to the configuration described in the first embodiment. A prism sheet 81 and a diffusion plate 82 are provided as light control means for controlling the expansion angle of light incident from the light source 26 to the incident surface 25 in between. In addition, the vertex angle of the prism of the prism sheet 81 is set to 100 degrees here. In addition, a filler 84 for alleviating the difference in refractive index is introduced between the light guide 24 and the polarizing plate 18 of the liquid crystal cell 10.

The light source 26 is realized by, for example, a fluorescent tube, but the output light from the fluorescent tube does not have any directivity and is randomly generated. For this reason, there exists a possibility that the light which injects into the inclination part 22 of the light guide 24 at an angle larger than a critical angle exists, and it becomes the leakage light from the inclination part 22, and may cause the display quality to fall.

Considering that the refractive index of PMMA suitably used as the material of the light guide 24 is about 1.5, the light whose incidence angle to the inclined portion 22 is equal to or less than the critical angle (about 42 °) becomes leakage light. In order to eliminate such leakage light, the expansion angle of the output light from the light source 26 may be controlled in advance so that incident light serving as the leakage light component does not enter the light guide 24.

Here, as shown in FIG. 28, the inclination angle of the inclination part 22 with respect to the interface 28 is made into (alpha). In addition, FIG. 28 extracts and shows the positional relationship of the inclination part 22, the interface 28, and the incident surface 25 in the light guide 24 for convenience of description, and the light guide 24 actually shows. It is not in this shape.

Further, when the angle of incidence of light incident from the incident surface 25 of the light guide 24 is ± β and the critical angle of the inclined portion 22 is θ _c , the angle of incidence θ of the aforementioned light on the inclined portion 22 is ,

θ = 90 °-α-β

Represented by

Therefore, the condition for the light incident on the inclined portion 22 from the incident surface 25 not to pass through the inclined portion 22 is

θ _c <θ = 90 ° -α-β

In other words,

Represented by

In this embodiment, the inclination angle α of the inclined portion 22 is set to 10 degrees. Since this and the critical angle θ ° are 42 °, β <38 ° is derived based on the above equation (3).

The output light from the light source 26 is once diffused in the diffusion plate 82 and enters the prism sheet 81. The prism sheet 81 has a function of condensing the diffused light in a specific angular range, and when the vertex angle of the prism is 100 degrees, as shown in FIG. 29, the diffused light is condensed in the angular range of about +40 degrees. The light condensed in the angle range of about ± 40 ° is further condensed by the refraction at the incident surface 25 when it enters the light guide 24, thereby being approximately +25. It becomes an extended light in the range of 4 degrees. That is, it is understood that the expansion angle of the light incident from the incident surface 25 is sufficiently included in the above range of β <38 °, so that no leakage light from the inclined portion 22 is generated.

As described above, in the reflective LCD according to the present embodiment, in order to suppress the expansion of the light source light, the inclined portion (1) is provided by providing the prism sheet 81 between the light source 26 and the incident surface 25 of the light guide 24. There is no leakage light from 22), and the display quality is further improved.

In addition, in this embodiment, although the vertex angle of the prism sheet 81 was 100 degrees, it is not necessarily limited to this angle. In addition, although the prism sheet 81 was used as a light control means which restricts the expansion of a light source light, if the same effect is acquired, it is not limited to this, For example, a collimator etc. can also be used. In addition, as shown in FIG. 30A, the same effect is obtained also by the structure which covered the periphery of the light source 26 with the ellipsoid mirror 98, and provided the light source 26 in the focus of this ellipsoid mirror 98. FIG. . In addition, as described in SID DlGEST P. 375 (1995), the expansion of the irradiation light from the light source 26 may be controlled using the waveguide 99 shown in FIG. 30B.

As described above, the front lighting apparatus according to the present invention is further provided with light control means for limiting the expansion of light from the light source between the light source and the incident surface.

The light from the light source is mainly reflected at the inclined portion of the second emission surface, but in order to reduce the component leaking to the outside of the light guide without total reflection at the inclined portion, the light from the light source has a certain degree of directivity, and It is preferable to reduce the component incident on the inclined portion at an angle smaller than the critical angle. For this reason, the above-described configuration includes light control means for restricting the expansion of light from the light source, so that the leakage light from the inclined portion is reduced, the light utilization efficiency is further improved, and the bleeding and blurring of the image of the illuminated object are prevented. do. As a result, a front lighting device as a surface light source from which a bright and clear image of a to-be-illuminated object is obtained is realized.

In the above-described configuration, the front lighting apparatus according to the present invention restricts the expansion of the light from the light source in a range in which the angle of incidence of light which the light control means directly enters the inclined portion of the second emission surface is larger than the critical angle.

Therefore, according to the above-described configuration, the light control means can limit the expansion of the light from the light source, thereby eliminating the component incident at an incident angle smaller than the critical angle among the light directly incident from the incident surface to the inclined portion. As a result, there is less leakage light from the inclined portion, and the utilization efficiency of the light is further improved, and the blurring and blurring of the image of the object to be illuminated are prevented. As a result, the front lighting apparatus as a surface light source from which a bright and clear object image to be obtained is realized.

Further, the front lighting apparatus according to the present invention restricts the expansion of light from the light source to a range in which a component that is directly incident from the incident surface to the first exit surface in the first light guide body is almost eliminated between the light source and the incident surface. It is also a configuration further comprising a light control means.

In the above configuration, when an air layer exists between the first light guide and the second light guide by introducing a filler that mitigates the refractive index difference at the optical interface existing between the first light guide and the second light guide. In comparison with the above, among the light incident directly from the light source to the first emitting surface, the component passing through the first emitting surface and entering the second light guide is increased. Some of these components are incident on the second light guide at a relatively large angle of incidence and cannot contribute to the illumination of the light to be illuminated. For this reason, the above structure can eliminate almost the component which directly injects into a 1st emitting surface among the light which injects into a light guide body from an incident surface by limiting the expansion of the light from a light source. Thereby, the component which injects into a 2nd light guide body from a 1st emitting surface at a comparatively large incidence angle can be reduced. As a result, the utilization efficiency of light is further improved and a bright front lighting apparatus is realized.

[Embodiment 8]

Another embodiment of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the structure which has a function similar to the structure demonstrated by each above-mentioned embodiment, and the description is abbreviate | omitted.

In the reflective LCD according to the present embodiment, the reflective LCD described in each of the above-described embodiments includes a filler which prevents attenuation of light due to a difference in refractive index between the front light (or the front light system) and the liquid crystal cell 10 ( Matching agent).

Here, a configuration in which the above filler is applied to the reflective LCD described in Embodiment 1 will be described as an example. In Embodiment 1, the light guide 24 of the front light 20 is laminated | stacked on the polarizing plate 18 of the liquid crystal cell 10 through the spacer of about 50 micrometers in diameter as demonstrated with reference to FIG. . As a result, the gap 29 is formed between the liquid crystal cell 10 and the light guide 24 at a uniform thickness substantially equal to the particle diameter of the spacer.

In the reflective LCD of the present embodiment, the filler 84 is filled in the gap 29 as shown in FIG. 32. Moreover, as the filler 84, UV curable resin, methyl salicylate, etc. can be used, for example. As a result, the interface 28 of the light guide 24 comes into contact with the filler 84 having a refractive index higher than that of the air, not air. The filler 84 preferably has a refractive index that is approximately equal to the refractive index of the light guide 24.

Thus, when the interface 28 of the light guide 24 is in contact with the filler 84, and when the interface 28 of the light guide 24 is in contact with the air as in each of the above-described embodiments, The behavior of light in (28) is different.

Of the incident light from the light source 26, as shown in FIG. 31A, a component that is almost perpendicularly incident on the incident surface 25 is directly incident and reflected from the incident surface 25 to the inclined portion 22, and then the interface. It enters into the liquid crystal cell 10 through the 28 and the filler 84. The behavior of light at the interface 28 at this time is the same as when the interface 28 is in contact with air (see FIG. 3A).

On the other hand, among the incident light from the light source 26, as shown in FIG. 31B, among the components which first enter the interface 23 from the incident surface 25, it is reflected by the flat part 21 like the light 85a. After entering, some may enter the interface 28. Among the light 85a and the incident light from the light source 26, as shown in FIG. 31C, the component that first enters the interface 28 from the incident surface 25 is the light guide 24. Since it is in contact with a filler 84 having a refractive index almost equal to), it is transmitted without any action at the interface 28.

These light are incident at very large incidence angles with respect to the liquid crystal layer 12 of the liquid crystal cell 10, but are reflected by the reflecting plate 17 and at the large incidence angles described above with respect to the interface 28 of the light guide 24. Since it is incident again, it is not reached by the observer.

However, in order to improve the utilization efficiency of the light source light, it is preferable to eliminate the component directly incident from the light source 26 to the interface 28. For this reason, as shown in FIG. 32, the incidence surface 25 is inclined so that this incidence surface 25 and the interface 28 may have an obtuse angle, and the component which injects directly from the incidence surface 25 to the interface 28 is made to be inclined. I can eliminate it.

Incidentally, the magnitude of the angle γ formed between the incident surface 25 and the interface 28 takes into account the expansion angle β after the light from the light source 26 is incident on the incident surface 25 as shown in FIG. 33. if,

γ ≥ 90 ° + β

It is more preferable that is. As a result, almost all of the light source light incident from the incident surface 25 enters the interface 23 direction, whereby the utilization efficiency of the light source light can be further improved.

As described above, the front lighting apparatus according to the present invention has a structure in which a filler is introduced between the first light guide and the second light guide to mitigate the difference in refractive index at the optical interface existing between these light guides. Therefore, in the above configuration, the attenuation of the light due to reflection at the optical interface existing between the first and second light guides is suppressed as compared with the case where an air layer exists between the first and second light guides. do. As a result, the utilization efficiency of the light source light is further improved, and the front lighting device as a brighter surface light source is realized. In addition, as described above, if the refractive index of at least one of the first and second light guides is the same as that of the filler, the number of optical interfaces between the first and second light guides can be reduced. effective.

Moreover, the front lighting apparatus which concerns on this invention is a structure in which the said incident surface and the said 1st output surface are arrange | positioned at an obtuse angle in addition to the said structure. Therefore, according to the said structure, since the incidence surface and the 1st emission surface are arrange | positioned at an obtuse angle, the component which directly injects into a 1st emission surface among the light source light incident from the incidence surface becomes small. As a result, the utilization efficiency of the light source light is further improved, and a brighter front lighting device is realized.

[Embodiment 9]

Another embodiment of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the structure which has a function similar to the structure demonstrated by each above-mentioned embodiment, and the description is abbreviate | omitted.

The reflective LCD according to the present embodiment is characterized in that the front light 20 is formed in a lid shape that can be opened and closed with respect to the liquid crystal cell 10.

In each of the above-described embodiments, various forms of the front light or the front light system as the front lighting device have been described. In particular, as in the configuration described in the fourth embodiment, the metal reflective film on the inclined portion 22 of the light guide 24 is described. In the case where 47 is provided, the metal reflective film 47 prevents the incidence of ambient light on the light guide 24. For this reason, although the surrounding environment is not dark enough to require the use of the reflective LCD in the illumination mode, the display in the reflective mode is particularly dark in situations where the amount of ambient light sufficient for use in the reflective mode is not obtained. have.

For this reason, as shown in FIG. 34, in the reflective LCD 91 of this embodiment, the front light 20 is fixed by the hinge (not shown) etc. one side, for example, and the liquid crystal cell 10 is carried out. The opening and closing is freely provided. The front light 20 is formed as an inner cover which can be opened and closed independently of the cover 92 covering the liquid crystal cell 10 and the front light 20.

Therefore, when the reflective LCD 91 is used in the illumination mode, the front light 20 is covered on the surface of the liquid crystal cell 10, that is, the lid 92 is opened and the reflective LCD 91 is used. When using 91 in the reflection mode, the front light 20 can be used with respect to the liquid crystal cell 10.

Accordingly, when used in the reflection mode, no reflection of light is caused by the front light 20, and a reflective LCD that can realize bright display at all times is realized.

In addition, although the structure in which at least one part of the front light 20 was fixed with respect to the liquid crystal display was demonstrated above, the structure which can fully unitize the front light 20 and detachable with respect to the liquid crystal cell 10 may be sufficient. However, in this case, it is necessary to consider the storage method of the front light 20 when removing it from the liquid crystal cell 10.

In addition, although the reflective LCD provided with the front light 20 in the inside cover form was demonstrated here, the structure in which the front light system demonstrated by each above-mentioned embodiment was provided in the inside cover form may be sufficient.

As described above, the reflective liquid crystal display device according to the present invention has a structure in which the front and back lighting devices as exemplified in the above embodiments are freely opened and closed with respect to the reflective liquid crystal element. Therefore, according to the above-described configuration, when the reflective liquid crystal display device is used in the state where the front lighting device is turned on, the front lighting device is not required by using the liquid crystal element with the front lighting device. It can be used in the state which opened the front lighting apparatus with respect to the liquid crystal element. This makes it possible to provide a reflective liquid crystal display device capable of realizing bright display at all times without the obstruction of ambient light incident by the front light device when the front light device is not required.

[Embodiment 10]

Another embodiment of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the structure which has a function similar to the structure demonstrated by each above-mentioned embodiment, and the description is abbreviate | omitted.

In each of the above embodiments, the reflective LCD as a configuration in which the front light or the front light system as the front lighting device and the reflective liquid crystal cell as the object to be illuminated has been described. However, the front light or the front light system as the front lighting device of the present invention is not used only in combination with the reflective liquid crystal cell. For example, as shown in FIG. 35, the lighting apparatus 95 which concerns on this embodiment is formed by the front light or front light system demonstrated in each said embodiment as an independent unit, and can illuminate various objects. Do.

For example, the above-described lighting apparatus 95 can be disposed on the book 96 and used as shown in FIG. 35. As a result, as shown in FIG. 36, only an area almost immediately below the lighting device 95 can be illuminated, so that, for example, when reading in a bedroom or the like, there is an effect that the surrounding people are not inconvenienced. .

In addition, each embodiment mentioned above does not limit this invention, It can variously change in the range of the invention. For example, PMMA is specifically exemplified as a material of the light guide, but if it can be light guided uniformly without attenuation and the refractive index is a suitable value, for example, a material such as glass, polycarbonate, polyvinyl chloride, or polyester may be used. It does not matter even if you use. In addition, the dimension of the inclination part of the said light guide, the flat part, etc. are an example to the last, It can design as possible in the range from which an equivalent effect is acquired.

As the liquid crystal cell, various LCDs such as a simple matrix LCD and an active matrix LCD can be used. In addition, although the liquid crystal cell of the ECB mode (fragmented-plate mode) which used the single polarizing plate which doubled the polarizer and the analyzer was used above, PDLC, PC-GH, etc. which do not use a polarizing plate can also be applied.

As described above, the front lighting apparatus according to the present invention is not limited to the reflective liquid crystal display element as an object to be illuminated as illustrated in each of the above embodiments, but is applied to the entire display medium that recognizes the display by illumination of light from the outside. It is used. Therefore, for example, by allowing the front lighting device to be detachable from the reflective liquid crystal display device, the front lighting device can be properly removed and used for another display medium when the reflective liquid crystal display device is not used. have.

[Embodiment 11]

Another embodiment of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the structure which has a function similar to the structure demonstrated by each above-mentioned embodiment, and the description is abbreviate | omitted.

As shown in FIG. 37, the reflective LCD of the present embodiment has the same configuration as that of the first embodiment in the case where the front light 20a is provided on the entire surface of the reflective liquid crystal cell 10a. The antireflection film (antireflection film) 13 which is a 2nd light guide (optical means) is arrange | positioned between the cell 10a and the front light 20a, and the flat part 21 formed in the light guide 24 is provided. And the fact that the width (pitch) of the inclined portion 22 is different, and that a reflective electrode (reflective plate: 17a) is formed inside the reflective liquid crystal cell 10a is different from the first embodiment.

First, the front light 20a will be described in detail. The front light 20a is mainly composed of the light source 26 and the light guide 24 as in the first embodiment, and the light guide 24 is used. The light source 26 as a linear light source covered with the reflecting mirror 27 is provided so as to contact the incident surface 25 of.

The interface (first emission surface: 28) on the liquid crystal cell 10a side of the light guide 24 is formed flat, and the interface facing the interface (second emission surface: 23) is the interface 28. The flat part 21 formed in parallel or substantially parallel, and the inclined part 22 inclined at a predetermined angle in the same direction with respect to the flat part 21 are alternately arrange | positioned, and are formed.

As described above, the light guide 24, like the first embodiment, has a stairway that moves downward from the light source 26 in a cross section in which the longitudinal direction of the light source 26 is the normal as shown in FIG. 37. It is formed in a shape.

38A to 38C, the shape of the light guide 24 will be described in more detail. 38A is a plan view of the light guide viewed from above the normal direction of the flat portion, and FIG. 38B is a side view of the light guide viewed from the normal direction of the incident surface, and FIG. 38C is a plane perpendicular to both the incident surface and the interface. It is sectional drawing cut into pieces.

As the material of the light guide 24, an acrylic plate is used in the present embodiment, and the light guide 24 can be processed into a step shape by molding the acrylic plate. In the present embodiment, the light guide 24 has a width W of 75 mm, a length of L of 170 mm, and a thickness h ₁ of the incident surface 25. 0 mm, the width w ₁ of the flat part 21 = 0. 2 mm is used. The width w ₂ of the inclined portion is about 10 μm by setting the step h ₂ = 10 μm of the inclined portion 22 and the inclination angle α = 45 ° with respect to the flat portion 21.

In this embodiment, with the width w ₂ of the light guide 24 has the incident surface 25, i.e. in the direction away from the light source 26, the flat portion 21 width w ₁ and the inclined portion 22 of the The sum w ₃ = 0.21 mm has a configuration that gradually decreases. The configuration of the flat portion 21 and the inclined portion 22 will be described in more detail based on FIG. 39 in addition to FIGS. 38A to 38C. Moreover, in the light guide 24, the direction which makes the longitudinal direction of the light source 26 which is a direction of the side away from the light source 26 a normal line is made into a 1st direction below, and is shown by the arrow A in the figure.

As shown in FIG. 39, the flat part 21 and the inclined part 22 are combined into one set, and the flat part 21 and the inclined part 22 from the side closest to the light source 26 are formed. Let 100 sets be the first block B ₁ . Then, the interval w ₄ in the direction along the first direction in the first block B ₁ is formed to be 21 mm.

The interval w ₄ in the second block B ₂ which is the next 100 sets of blocks is formed to be 20 mm. In addition, the next interval in the third block B ₃ of the interval w ₄ is formed so as to be formed such that 19㎜, and the fourth block B ₄ 18㎜ the interval w of the _4, and a fifth block B ₅ w ₄ is formed to be 17 mm.

Therefore, in the present embodiment, each block of the light guide 24 is formed from the end face on the light source 26 side to the end face on the side where the light source 26 is not disposed along the first direction. The interval w ₄ is reduced by 1 mm. That is, as the distance from the light source 26 increases, the sum of the pitch of the flat part 21 and the pitch of the inclined part 22 (width of the flat part 21) for every 100 sets of the flat part 21 and the inclined part 22. The sum w ₃ of w ₁ and the width w ₂ of the inclined portion 22 is formed so as to decrease by 10 μm (1/100 mm). 38A to 38C do not show the decrease in the pitch of the flat portion 21 and the inclined portion 22 for convenience of explanation.

In the light guide 24, the inclined portion 22 mainly serves as a micro light source portion that is a surface that reflects light from the light source 26 toward the interface 28. On the other hand, the flat part 21 mainly acts as a surface which transmits the reflected light toward the observer side when the illumination light from the front light 20a returns as the reflected light from the liquid crystal cell 10a. The operation of these parts is the same as that of the first embodiment.

In addition to the step-shaped configuration, the light guide 24 in the front light 20a has a pitch of one pair for each 100 pairs of the flat portion 21 and the inclined portion 22, for example, 10 µm. It is equipped with the structure which makes it small, ie, the pitch of a staircase becomes small as it moves away from the light source 26. Therefore, as shown in FIG. 40A, the number per unit area of the inclined portion 22 increases as the distance from the light source 26 increases.

Incident light incident on the incident surface 25 from the light source 26 is reflected by the inclined portion 22 serving as the micro light source portion, but the number per unit area of the inclined portion 22 increases as it moves away from the light source 26. Therefore, the luminance of the reflective liquid crystal cell 10a, which is the illuminated object illuminated by the front light 20a, is increased at a position away from the light source 26. Usually, since the brightness | luminance tends to fall so that it is far from the light source 26, if it is the structure of the light guide 24 of this embodiment, it will be far from the light source 26 in the interface 28 (1st output surface). It is possible to offset the lowering of the luminance and guide the light from the light source 26 to the whole to-be-illuminated object at high angle efficiently. As a result, the luminance distribution on the interface 28 side, which is the interface (first exit surface) on the side to be illuminated, can be averaged.

On the other hand, in the conventional front light 120 in which the light guide 124 is formed in the wedge-shaped flat form as shown in FIG. 40B, incident light which entered the incident surface 125 from the light source 26, It is reflected by the interface 123 as it is. For this reason, the luminance at the first emission surface (interface 128 in the front light 120) decreases as it moves away from the light source 26.

In addition, as shown in FIG. 41, the distribution state of the brightness | luminance on a 1st exit surface is compared with the graph F which shows the brightness distribution of the conventional front light 120, and of the front light 20a of this embodiment. The graph E showing the luminance distribution is substantially constant even at a position where the distance from the light source 26 is large. Therefore, it turns out that the front light 20a of this embodiment is excellent in the uniformity of the brightness distribution in a 1st output surface (interface: 28).

Moreover, in the light guide 24 of the said structure, since the pitch of a staircase is 0.21 mm, the pitch of the black matrix formed around the pixel of the reflective liquid crystal cell 10a corresponding to the light guide 24. And the pitch of the groove of the inclined portion 22 are shifted. As a result, generation of moire patterns due to interference between the black matrix and the inclined portion 22 can be suppressed, so that the display quality of the resulting reflective LCD can be improved. In addition, this point is mentioned later.

As a result of the emission angle characteristic of the light guide 24, as shown in Fig. 42, in the graph G on the reflective LCD side (28 side of the object) as the irradiated object, the light receiving angle is from -10 ° to -5 °. The brightness | luminance rises until it reaches to ² , 000 cd / m <^2> as a peak between and. On the other hand, in the graph H on the observer's side (interface 23 side), the luminance is up to 500 cd / m ² when the light receiving angle is −60 °, and the luminance is about 100 cd / near 0 °, the angle at which the reflective LCD is observed. m ² or less.

In this way, the light from the light source 26 disposed on the end face of the light guide 24 can be emitted from the interface 28 at an angle substantially perpendicular to the object to be illuminated (reflective LCD). At the same time, there is almost no light leakage on the observer side on the interface 23 side, and the light from the light source 26 can be efficiently guided to the object to be illuminated at a high angle.

In addition, although the fluorescent tube is used as the light source 26 in this embodiment, it is not limited to this as the light source 26, For example, LED (light emitting diode), an EL element, or a tungsten lamp can be used. .

Next, the liquid crystal cell 10a will be described. As shown in FIG. 37, the liquid crystal cell 10a is similar to the liquid crystal cell 10 of the first embodiment as a basic configuration, but the reflecting plate is made of a liquid crystal cell ( The points formed in 10a) are different.

As shown in Fig. 43, the liquid crystal cell 10a sandwiches the liquid crystal layer 12 by a pair of electrode substrates 11a and 11c, and further includes a phase difference plate on the electrode substrate 11a side that is the display surface side. 49) and the polarizing plate 18 are comprised. In addition, although only one piece is provided in FIG. 43, two or more phase difference plates 49 (not shown in FIG. 37) do not need to be provided.

The electrode substrate 11a is provided with a color filter 38 on a glass substrate 14a having light transmittance, and a transparent electrode 15a (scanning line) is provided thereon to cover the transparent electrode 15a. The liquid crystal aligning film 16a is formed. Moreover, an insulating film etc. can also be formed with respect to the electrode substrate 11a as needed. In addition, the color filter 38 is not shown in FIG.

On the other hand, the electrode substrate 11c has an insulating film 19 formed on the glass substrate 14b, a reflective electrode (reflective plate) 17a is formed thereon, and the liquid crystal alignment film 16b so as to cover the reflective electrode 17a. ) Is formed. A plurality of irregularities are formed on the surface of the insulating film 19, and a plurality of irregularities are formed on the surface of the reflective electrode 17a covering the insulating film 19.

The reflective electrode 17a serves as a liquid crystal drive electrode and a reflecting plate for driving the liquid crystal layer 12. As the reflective electrode 17a, an aluminum (Al) reflective electrode having excellent reflection characteristics is used. The insulating film 19 is formed of an organic resist, and the contact holes and the uneven portions of the insulating film 19 are formed by photolithography described later. The material, the formation method, etc. of the said glass substrate 14a * 14b, the transparent electrode 15a * 15b, and the liquid crystal aligning film 16a * 16b are the same as that of the said 1st Embodiment.

The formation method of the said electrode substrate 11c is demonstrated in more detail based on FIG. 44A-44E.

First, as shown in FIG. 44A, the organic resist is apply | coated to the whole surface on the glass substrate 14b, and it bakes, and the insulating film 19 is formed. Subsequently, as shown in FIG. 44B, by irradiating the insulating film 19 with the ultraviolet ray 30a through the mask 30, the irradiation portion of the ultraviolet ray 30a is removed, and as shown in FIG. 44C, the ultraviolet ( The irradiated portion of 30a) is formed in a predetermined pattern.

Next, as shown in FIG. 44D, the insulating film 19 formed in the predetermined pattern is subjected to heat treatment at 180 ° C. for baking, thereby causing thermal strain in the organic resist. By this thermal deformation, the uneven portion 19a is formed.

Finally, as shown in Fig. 44E, aluminum (Al) is vacuum deposited to cover the uneven portion 19a. Thereby, the reflective electrode 17a in which the uneven part was formed in the surface along the uneven part 19a is formed.

The electrode substrate 11c and the electrode substrate 11a obtained in this way are arranged so that the liquid crystal alignment films 16a and 16b of each other face each other, and the directions of the rubbing treatment are antiparallel, and are bonded using an adhesive agent. . In addition, between the electrode substrates 11a and 11c, in order to make the space | interval of the clearance gap formed by this electrode substrate 11a and 11c uniform, the particle diameter 4. 5 micrometer glass bead spacers (not shown) are previously scattered. The liquid crystal layer 12 is formed by introducing a liquid crystal into the gap by vacuum degassing. The material of the liquid crystal layer 12 is also the same as that of the first embodiment.

Although the reflective liquid crystal cell 10a of this embodiment is manufactured as mentioned above, manufacturing processes, manufacturing conditions, etc. other than the above-mentioned description are the same as the reflective liquid crystal cell 10 in the said Embodiment 1, Omit.

The pattern of the uneven portion (that is, the pattern of the uneven portion 19a of the insulating film 19) formed on the reflective electrode 17a of the electrode substrate 11c is irregularly formed to enter the reflective liquid crystal cell 10a. The incident light is formed to diffusely reflect in a specific direction.

It is preferable that the difference between the vertex of the convex portion and the bottom of the concave portion in the uneven portion in the insulating film 19 is in the range of 0.01 to 2 µm. When the difference between the apex of the convex part in the uneven part and the bottom of the concave part is within this range, incident light can be diffused without affecting the orientation of the liquid crystal molecules and the cell thickness of the liquid crystal cell.

A case where the reflective characteristic of the reflective electrode 17a thus formed is compared with the reflective characteristic of the standard white plate MGO which exhibits almost the same diffuse reflective characteristic as the paper will be described based on FIG. 45. The MGO (and paper, etc.) exhibits reflection characteristics showing isotropy as shown by the broken line graph M in the figure. On the other hand, the reflective electrode 17a (MRS) has a diffuse reflection characteristic showing directivity at an angle of ± 30 ° as shown by the solid line graph N in the figure.

Even if light enters the reflective liquid crystal cell 10a including the reflective electrode 17a from a direction other than the positive reflection direction, the image can be observed. Incidentally, the reflection characteristic of the reflective electrode 17a is not limited to that shown in FIG. 45, but is appropriately changed by the design of the reflective electrode 17a so as to correspond to the type of the device in which the reflective LCD is used. It is possible to correspond to

In addition, since the reflective electrode 17a is formed to be adjacent to the liquid crystal layer 12 in the reflective liquid crystal cell 10a, the reflecting plate is formed on the back side of the reflective liquid crystal cell 10a (the side of the light guide 24 in contact with the light guide member). The generation of parallax by the glass substrate 14b can be eliminated compared with the case where it is formed in the surface on the side opposite to the surface. Therefore, the double transfer of an image can be suppressed in the reflective LCD obtained. It is also possible to simplify the configuration of the reflective liquid crystal cell 10a.

37 and 43, even if the display mode of the reflective liquid crystal cell 10a is a polarization mode in which the polarizing plate 18 is provided, the reflection electrode 17a according to the present embodiment is further shown in FIG. As shown in 46, the reflection type liquid crystal cell of the guest host mode (no polarizing plate) may be used. In addition, about this reflective liquid crystal cell, since the basic structure is substantially the same as that of the reflective liquid crystal cell 10a, detailed description is abbreviate | omitted.

Next, the pixel structure arranged in the liquid crystal cell 10a will be described. As shown in FIG. 47, the reflective liquid crystal cell 10a is along the longitudinal direction of the reflective liquid crystal cell 10a. A plurality of scan lines 54 are formed, and a plurality of signal lines 55 are formed in a direction orthogonal to the direction in which the scan lines 54 are formed. A plurality of pixels 56... Are formed to correspond to the lattice pattern formed by the scanning line 54... And the signal line 55.

One pixel 56 consists of pixel electrodes 56a corresponding to three color filters of red (R), green (G), and blue (B). These pixel electrodes 56a are arranged in the order of R, G, and B along the direction in which the scan lines 54 are formed.

In the shape of the reflective liquid crystal cell 10a, in the present embodiment, diagonal 6.5 type size (length W _L = 58 mm, width L _L = 154.5 mm), 54 scanning lines Xm = 240, 55 signal lines Yn = 640 pieces. In addition, the pitch P _L = 0 of the pixel 56 arranged in the reflective liquid crystal cell 10a. 24 mm (R, G, B). The pixel 56... A black matrix (hereinafter referred to as BM), not shown, is formed in the periphery of 8 mu m in width.

In the reflective LCD according to the present embodiment, the above-described reflective liquid crystal cell 10a and the front light 20a are combined. Here, in the front light 20a, the pitch of the flat part 21 and the inclined part 22 of the light guide 24 is 0.2 mm as described above, and the scanning line 54... It is smaller than the pitch. Therefore, the pitch of BM and the pitch of the groove of the inclined portion 22 in the reflective liquid crystal cell 10a can be varied. When these pitches shift, the generation of the moire pattern due to the interference between the BM and the inclined portion 22 can be suppressed. Therefore, the display quality of the reflective LCD obtained can be improved.

In the configuration of the light guide 24 described above, the pitch of the flat portion 21 and the inclined portion 22 is smaller than the pitch of the scan line 54..., But the pitch can be made larger than the pitch of the scan line 54. have. That is, in order to suppress generation | occurrence | production of a moire pattern, the pitch of the groove | channel of the inclined part 22 and the pitch of BM may shift.

Here, the sum w ₃ of the width w ₁ of the flat part 21 and the width w ₂ of the inclined part 22 is used as the pitch of the groove of the inclined part 22. The BM is formed so as to shield the scanning line 54... And the signal line 55..., But the scanning line 54... Is parallel to the groove of the inclined portion 22, so that the pitch of the scanning line 54. Let P ₁ be the pitch of BM.

In order to displace the pitch of the grooves of pitch and BM of the inclined portion 22, if the w ₃ and P ₁ mismatched (W ₃ ≠ P ₁₎ state, but the relationship between the W _3, and P ₁ as the , w is ₃ or greater than twice the width of P ₁ (w _3> 2P _1), or, W ₃ are particularly preferably smaller than the width _{(W 3 <1 / 2P 1} ) half of P _1.

If a departure from the range of the above-described relationship with the w ₃ and P ₁ is, even if he is in the home pitch and BM pitch of the inclined portion 22 shifted, the optically determined, it is possible to consider that roughly match. Therefore, since generation | occurrence | production of a moire pattern cannot be suppressed effectively, it is unpreferable.

The back angle of the flat portion 21, the width w ₁ and the inclined portion 22, the width w ₂ and, w ₁ and w ₂ the sum w _3, the inclined portion 22 with those of in the present embodiment is, It is not limited to the numerical value mentioned above, What is necessary is just to form according to the pixel structure of the reflective liquid crystal cell 10a used.

In addition, in this embodiment, although the pitch of the flat part 21 is reduced in the direction away from the light source 26 (1st direction), in order to average brightness distribution, the inclination part 22 replaces the pitch. By changing the angle of, the sum of the pitches of the flat portion 21 and the inclined portion 22 may be reduced. For example, the flat portion 21 is made smaller, and the angle α formed between the flat portion 21 and the inclined portion 22 is made smaller in the direction away from the light source 26 (first direction). ) And the pitch of the inclined portion 22 can be reduced. Also in this case, since the entrance light can be efficiently emitted to the inclined portion 22 in the direction away from the light source 26 (first direction), the luminance distribution can be averaged.

In addition, the reflective LCD according to the present embodiment includes, in addition to the front light 20a and the reflective liquid crystal cell 10a of the above configuration, between the front light 20a and the reflective liquid crystal cell 10a. It is the structure in which the anti-reflective film as a 2nd light guide body is arrange | positioned.

In the reflection type LCD, the anti-reflection film as the anti-reflection film is provided at the interface (first exit surface) of the polarizing plate 18 and the light guide 24 disposed on the reflection type liquid crystal cell 10 in the reflection type LCD. (13) is bonded.

In the present embodiment, the antireflection film 13 uses an antireflection film (TAC-HC / AR) manufactured by Nitto Electric Corporation. This antireflection film 13 is a multilayer structure film having a four-layer structure. Specifically, a base material layer triacetyl cellulose (TAC) using the film, and moreover, the MgF ₂ layer as a first layer, CeF ₃ layer as the second layer, the third layer as a TiO ₂ layer, a fourth layer MgF _It becomes the antireflection film 13 in which _two layers were formed, respectively.

The TAC film has a refractive index n _t = 1. It is 51 and is 100 micrometers in thickness. Also, MgF ₂ layer of the first layer, the refractive index n _m = 1. The CeF ₃ layer having a thickness of about 100 nm and a second layer of 38 has a refractive index of n _c = 1. 63 and a thickness of about 120 nm and the TiO ₂ layer of the third layer had a refractive index of n _ti = 2. 30 MgF ₂ layer of a thickness of about 120 nm and a 4th layer has refractive index n = 1. It is 38 and is about 100 nm thick. These 1st-4th layers are formed on the TAC film of a base material layer sequentially by the vacuum vapor deposition method.

In addition, at the time of sticking with the front light 20a, a layer of an acrylic adhesive having a refractive index n ₁ almost equal to the refractive index n _{2 of} the acrylic material used for the light guide 24 is formed. Therefore, the antireflection effect can be improved with almost no change in the input / output conditions of the light in the light guide 24, and the unevenness of the luminance distribution and the generation of iridescent spectroscopy can also be prevented.

In addition, the TAC film of the said 1st layer is not an essential structure as the structure of the anti-reflection film 13, For example, except for a 1st layer, the 2nd-4th layer is directly connected to the light guide 24. FIG. It can also be laminated. In this case, however, the manufacturing cost may be slightly increased.

The antireflection film 13 of the multilayer structure film is constituted of a λ / 4-λ / 2-λ / 4-λ / 4 wavelength plate for incident light having a wavelength plate of λ = 550 nm. Therefore, the antireflection film 13 can function as the antireflection film 13 in the light wavelength band.

In the light guide 24 described above, the inclined portion 22 formed on the surface (interface: 23) of the light guide 24 functions as a micro light source for the reflective liquid crystal cell 10a. Therefore, although light is irradiated to the reflective liquid crystal cell 10a from the inclination part 22, it is opposed to the interface of the light guide 24 and the reflective liquid crystal cell 10a, ie, the interface 23. As shown in FIG. In the interface 28 which is a surface, about 4% of the light from the inclined portion 22 is reflected and becomes reflected light.

By the generation of the reflected light, the reflection image is formed from the interface 28 to the interface 23 side. Therefore, this reflection image and the image in the said inclination part 22 mutually interfere or diffraction, and the spot of a brightness | luminance distribution and the spectroscopy of a rainbow color generate | occur | produce on the surface of a reflection type LCD from an observer.

However, in the reflective LCD according to the present embodiment, the anti-reflection film (anti-reflection film: 13) is provided between the reflective liquid crystal cell 10a and the front light 20a, that is, at the interface 28 side of the light guide 24. ), The generation of the reflected light generated by the incident light from the inclined portion 22 reflected at the interface 28 can be suppressed.

Therefore, the interference or diffraction between the image in the inclined portion 22 serving as the micro light source portion and the reflected image reflected at the interface 28 side can be prevented. Therefore, unevenness of the luminance distribution on the display observed on the observer side (interface 23 side) and generation of rainbow spectral can be prevented.

When the brightness distribution of the display in the reflective LCD of this embodiment is compared with the case where this antireflection film 13 is arrange | positioned and the case where it is not arrange | positioned, as shown in FIG. 48, as shown in FIG. It is understood that the graph C in the case where the antireflection film 13 is disposed is more consistent than the graph D in the case of not arranging 13), and the luminance itself is also improved. Can be.

Moreover, since the antireflection film 13 of the said structure can use a commercially available thing as it is, it can suppress the raise of the manufacturing cost of the front light 20a. Therefore, an inexpensive front light 20a and a reflective LCD provided with the same can be obtained.

In addition, since the antireflection film 13 is adhered with an adhesive having a refractive index n _{1 that} is approximately equal to the refractive index n ₂ of the light guide 24 that is the first light guide, the input / output conditions of light in the light guide 24 are hardly changed. The anti-reflection effect can be improved.

Moreover, about the structure and material of the said antireflection film 13, it is not limited to said structure and material. For example, as a structure of a wave plate, it may be set as (lambda) / 4- (lambda) / 2- (lambda) / 2- (lambda) / 2- (lambda) / 4. By setting it as such a wave plate structure, the antireflection effect is acquired in a wider wavelength band. Moreover, the antireflection film of the single layer structure of (lambda) / 4 wave plate may be sufficient. However, in this case, there exists a possibility that the wavelength band from which an antireflection effect is acquired may become narrow.

Thus, the pitch of the flat part 21 and the inclined part 22 formed in the surface (interface: 23) of the light guide 24 is small as it goes to the direction away from the light source 26 (first direction). By forming it so that the reflected light amount reflected by the said inclination part 22 can be increased in the direction away from a light source than before. Therefore, the luminance distribution in the interface 23 (first emission surface) of the light guide 24 can be averaged.

Furthermore, by forming the pitch of the flat part 21 and the inclined part 22 formed in the interface 23 of the light guide 24 in the front light 20a smaller than the pitch of the reflective liquid crystal cell 10a, The generation of a moire pattern caused by interference of light caused by the BM formed around the pixel 56... And the groove of the inclined portion 22 can be suppressed. Therefore, deterioration of the display quality of a reflective LCD can be prevented.

In addition, the anti-reflection film (anti-reflection film) 13 is provided between the reflective liquid crystal cell 10a and the front light 20a, so that the unevenness of the luminance distribution at the interface 23 of the light guide 24 Generation of iridescent spectroscopy can be prevented. Therefore, a reflective liquid crystal LCD which is brighter and has a higher display quality can be obtained.

In addition, by forming the uneven portion in the reflective electrode 17a in the reflective liquid crystal cell 10a, incident light is diffused without affecting the alignment and the cell thickness of the liquid crystal molecules. Therefore, even if light enters the reflective liquid crystal cell 10a from a direction other than the positive reflection direction, the image can be observed.

As described above, the front lighting apparatus according to the present invention suppresses the second light guide from reflecting light from the second light exit surface in the first light guide to the first light exit surface in the first light guide. It is a structure which is an optical means.

Usually, in the 1st light emission surface in a 1st light guide body, the light from the inclination part provided in the 2nd light emission surface is reflected, and it becomes reflected light. By the generation of the reflected light, a reflection image is formed from the first emission surface of the first light guide body to the second emission surface. As a result, the reflected image and the image in the inclined portion are mutually interfered or diffracted, and the unevenness of the luminance distribution and the spectroscopic rainbow color appear on the surface of the object to be viewed from the observer.

However, according to the above configuration, since the front lighting apparatus includes the optical means as the second light guide member, it is possible to suppress the generation of the reflected light generated by the incident light reflected from the inclined portion at the first exit surface. Therefore, it is possible to prevent the interference or diffraction between the image in the inclined portion serving as the micro light source portion and the reflected image by the reflected light. Therefore, unevenness of the luminance distribution on the display observed on the observer's side (second emission surface) and generation of rainbow spectral can be prevented.

In the front lighting apparatus by this invention, the said optical means is an anti-reflection film. Therefore, since the antireflection film (antireflection film) marketed as said optical means can be used as it is, the raise of the manufacturing cost of a front illumination apparatus can be suppressed. As a result, a cheap front lighting apparatus can be provided.

In the front lighting apparatus by this invention, the said optical means is adhere | attached with the 1st light guide body by the adhesive agent which has a refractive index substantially the same as the refractive index which a 1st light guide body has. Therefore, the antireflection effect can be improved without changing the input / output conditions of the light in the first light guide substantially.

In the front lighting apparatus which concerns on this invention, the sum of the pitch of the flat part formed in the said light guide and the pitch of the inclined part becomes small as it moves away from the said incident surface. Therefore, the number per unit area of the inclined portion increases as the distance from the light source increases. As the inclined portion increases, the luminance on the surface of the object to be illuminated increases as the position moves away from the light source. In general, since the luminance tends to decrease as the position is farther from the light source, in the above configuration, the increase in the inclination portion cancels the decrease in the luminance of the light object as it moves away from the light source, so that the light from the light source can be efficiently transmitted at a high angle. Can be induced. As a result, the luminance distribution on the surface of the to-be-illuminated object can be averaged.

The reflective liquid crystal display device according to the present invention includes a front illumination device having the above-described configuration, and the reflective liquid crystal element includes a scan line, and the pitch of the scan line is greater than the pitch of the scan line. The sum of the pitch of the flat part and the pitch of the inclined part is smaller.

Therefore, according to the above configuration, since the sum of the pitches of the flat portion and the inclined portion is smaller than the sum of the pitches of the scanning lines, the black matrix formed around the pitch of the inclined portion of the front lighting apparatus and the pixels of the reflective liquid crystal element. The pitch is shifted. As a result, generation | occurrence | production of a moire pattern by interference of a black matrix and an inclination part can be suppressed, and the display quality of the reflection type liquid crystal display device obtained can be improved.

In the reflection type liquid crystal display device according to the present invention, in the above configuration, the sum of the pitch of the flat portion and the pitch of the inclined portion may be larger than the pitch of the scan line. Also in this configuration, the pitch of the inclined portion of the front illumination device and the pitch of the black matrix formed around the pixels of the reflective liquid crystal element are shifted. As a result, generation | occurrence | production of the moire pattern by the interference of a black matrix and an inclination part can be suppressed, and the display quality of the reflection type liquid crystal display device obtained can be improved.

In the above-described configuration, the reflective liquid crystal display device according to the present invention includes a reflective plate having a concave-convex portion such that the reflective liquid crystal element does not affect the cell thickness. As such, the reflecting plate diffuses incident light without affecting the orientation of the liquid crystal molecules and the cell thickness of the liquid crystal cell. Therefore, even if light enters from a direction other than the positive reflection direction, the image can be observed.

In the above-described configuration, the reflective liquid crystal display device according to the present invention is a reflective electrode which serves as a liquid crystal drive electrode for driving the liquid crystal layer of the reflective liquid crystal element, and is provided adjacent to the liquid crystal layer. Therefore, generation | occurrence | production of the parallax by the electrode substrate which comprises a reflection type liquid crystal element can be eliminated compared with the case where a reflecting plate is not provided adjacent to a liquid crystal layer. As a result, in the reflection type liquid crystal display device obtained, double transfer of an image can be suppressed. In addition, since the reflecting plate also serves as a liquid crystal drive electrode, it is also possible to simplify the configuration of the reflective liquid crystal display device.

[Embodiment 12]

Another embodiment of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the structure which has a function similar to the structure demonstrated by each above-mentioned embodiment, and the description is abbreviate | omitted.

As shown in FIG. 49, the reflective LCD of the present embodiment has a basic configuration similar to that of the second embodiment, but includes a third light guide (optical means) between the reflective liquid crystal cell 10 and the front light system 51. ) Is different in that the antireflection film (reflection prevention film) 13 is disposed.

The antireflection film 13 is the same as that used in the eleventh embodiment. In addition, since description of the antireflection film 13, the reflection type liquid crystal cell 10, and the front light system 51 is performed in said Embodiment 2 and 11, it abbreviate | omits.

In this embodiment, the said antireflection film 13 functions as a 3rd light guide in addition to the light guide 24 which is a 1st light guide and the light guide 40 which is a 2nd light guide.

When this anti-reflection film 13 is not formed, the light from the inclined portion 22 formed at the interface 23 (second emission surface) of the first light guide 24 is the second light guide 40. 4% is reflected from the bottom (second surface: 42) of the bottom surface to become reflected light. The image of the inclined portion 22 formed by the reflected light and the inclined portion 22 in the light guide 24 interfere with each other. As a result, the interface 28 of the light guide 24 is first emitted. Surface) will cause unevenness of the luminance distribution.

Therefore, in the reflective LCD according to the present embodiment, the same reflection as that in the eleventh embodiment is performed between the bottom face 42 of the second light guide 40 and the display surface side surface of the reflective liquid crystal cell 10. The prevention film 13 is arrange | positioned. By arrange | positioning this antireflection film 13, generation | occurrence | production of the said reflected light can be suppressed effectively. Therefore, it is possible to realize a reflective LCD which can suppress unevenness of the luminance distribution at the interface 28 and realize high quality display.

When comparing the case where the said anti-reflection film 13 is arrange | positioned with a reflection type LCD and the case where it is not arrange | positioned, it is shown in FIG. 50B which shows the luminance distribution in the case where it is not arrange | positioned, as shown to FIG. In comparison, in FIG. 50A which shows the luminance distribution in the case where the said antireflection film 13 is arrange | positioned, the pitch p of the peak of a luminance is substantially over the whole bottom face 42 of the 2nd light guide 40. Since it is the same, the peak of brightness | luminance is gentle and the unevenness of brightness | luminance distribution is reduced. Thus, it can be seen that the state of the luminance distribution is improved.

In addition, the antireflection film 13 adheres the antireflection film 13 with an adhesive having a refractive index n _{1 that} is approximately equal to the refractive index n ₂ of the second light guide 40. Therefore, the reflection prevention effect can be improved without changing the input / output conditions of the light in the 2nd light guide 40 substantially.

Moreover, since the commercially available thing can be used as it is as the antireflection film 13 of the said structure, the raise of the manufacturing cost of the front light system 51 can be suppressed. Therefore, an inexpensive front light system 51 and a reflective LCD provided with the same can be obtained.

As described above, the front lighting apparatus according to the present invention is an optical for suppressing reflection of light from the second exit surface in the first light guide on the second surface of the second light guide. It is a structure provided with a means as a 3rd light guide.

Usually, a part of the light from the inclination part formed in the 2nd emitting surface of a 1st light guide body is reflected on the 2nd surface in a 2nd light guide body, and it becomes reflected light. By the generation of the reflected light, a reflection image is formed from the first emission surface of the first light guide body to the second emission surface. As a result, the reflection image and the image in the inclined portion mutually interfere or diffraction, and the unevenness of the luminance distribution and the spectroscopic rainbow color appear on the surface of the object to be viewed from the observer.

However, according to the above configuration, since the front lighting apparatus includes the optical means as the third light guide member, it is possible to suppress the generation of the reflected light generated by the incident light reflected from the second surface. Therefore, it is possible to prevent the interference or diffraction between the image at the inclined portion serving as the micro light source portion and the reflected image by the reflected light. Therefore, unevenness of the luminance distribution on the display observed on the observer's side (second emission surface) and generation of rainbow spectral can be prevented.

In the front lighting apparatus which concerns on this invention, the said optical means is an anti-reflection film. Therefore, since a commercially available antireflective film (antireflection film) can be used as an optical means as it is, an increase in the manufacturing cost of a front lighting apparatus can be suppressed. Therefore, an inexpensive front lighting device can be provided.

In the front illuminating device which concerns on this invention, the said optical means is adhere | attached with a 2nd light guide body by the adhesive agent which has a refractive index substantially the same as the refractive index which the said 2nd light guide body has. Therefore, the antireflection effect can be improved without changing the input / output conditions of the light in the second light guide substantially.

Specific embodiments or examples made in the Detailed Description of the Invention only disclose the technical contents of the present invention, and are not to be construed as limited to such specific embodiments only. It can change and implement in various ways within the scope of the claim of description.

Claims (44)

Has a light guide disposed in front of the light source and the object to be illuminated, The light guide includes an incident surface on which light from a light source is incident, a first emitting surface that emits light toward an object to be illuminated, and a second emitting surface that emits reflected light from an object to face the first emitting surface. With The second emission surface is formed in a stepped shape in which the inclined portion mainly reflecting light from the light source toward the first emission surface and the flat portion mainly transmitting the reflected light from the light to be illuminated are alternately arranged. The total illumination of the projection to the first emission surface of the flat portion is greater than the total of the projection to the first emission surface of the inclined portion. The front lighting apparatus according to claim 1, further comprising a second light guide for averaging the luminance distribution of the light emitted from the first light emitting surface when the light guide is the first light guide. 3. The light of claim 2, wherein the second light guide is opposed to the first surface of the first light guide and is incident from the first light guide through the first surface. 4. While having a second surface for emitting the light to the object, The first and second surfaces are formed such that the distance from each inclined portion at the second exit surface of the first light guide to the second surface is substantially uniform. 4. The front lighting apparatus according to claim 3, wherein the refractive index of the first light guide is substantially equal to that of the second light guide. The second surface of the second light guide is provided with an optical means as a third light guide to prevent the light from the second exit surface of the first light guide from being reflected at the second surface. Front lighting device characterized in that. A front lighting device according to claim 5, wherein said optical means is an anti-reflection film. The front illuminating device according to claim 5, wherein the optical means is adhered to the second light guide by an adhesive having an index of refraction substantially equal to that of the second light guide. The front lighting apparatus according to claim 2, wherein the second light guide is a light scatterer that scatters the light emitted from the first light emitting surface of the first light guide. The light scattering body of claim 8, wherein the light scattering body is an anisotropic scattering body which scatters only incident light in a predetermined angle range. At least a part of the angular range from which the light emitted from the first light guide is incident on the second light guide is included in the predetermined angular range. The front lighting device of claim 8, wherein the light scatterer is a front scatterer. 3. The front light of claim 2, wherein the second light guide is an optical means for suppressing reflection of light from the second exit surface of the first light guide at the first exit surface of the first light guide. Device. 12. A front lighting apparatus according to claim 11, wherein said optical means is an anti-reflection film. 12. A front lighting apparatus according to claim 11, wherein said optical means is adhered to said second light guide by an adhesive having an index of refraction substantially equal to that of said second light guide. The front lighting apparatus according to claim 2, wherein a filler is introduced between the first light guide and the second light guide to mitigate the difference in refractive index at the optical interface existing between the light guides. 15. The apparatus according to claim 14, further comprising light control means for limiting the expansion of light from the light source between the light source and the incident surface in such a range that there is almost no component directly incident from the incident surface to the first exit surface of the first light guide. Front lighting device characterized in that. The front illumination device according to claim 1, wherein the incident surface is present on the side of the light guide. 17. The front lighting apparatus of claim 16, wherein a sum of the projected projections of the inclined portion in a plane perpendicular to the first exit surface is approximately equal to the sum of the projected projections of the incident surfaces in the plane. The front lighting apparatus according to claim 16, wherein the incidence surface and the first emission surface are arranged at an obtuse angle. The front lighting apparatus according to claim 1, further comprising a light collecting means for allowing light from a light source to be incident only on the incident surface. The front lighting apparatus according to claim 1, wherein the total of the projections projected to the first exit surface of the inclined portion is smaller than the total of the projections exited to the first exit surface of the flat portion. The front lighting apparatus of claim 1, wherein the flat portion has an inclination angle of 10 ° or less with respect to the first exit surface or parallel to the first exit surface. According to claim 1, When the refractive index of the light guide is n ₂ and the refractive index of the external medium in contact with the inclined portion is n ₁ , the incident angle θ of light incident from the light source to the inclined portion is θ ≥ arcsin (n ₁ / n ₂ ) A front lighting device characterized in that it satisfies. The front lighting apparatus according to claim 1, wherein a reflection member for reflecting light is provided on a surface of the inclined portion. 24. The method according to claim 23, wherein when the refractive index of the light guide is n ₂ and the refractive index of the external medium in contact with the inclined portion is n ₁ , the incident angle θ of light incident from the light source to the inclined portion is θ <arcsin (n ₁ / n ₂ ). A front lighting device characterized in that it satisfies. 24. A front lighting apparatus according to claim 23, wherein a light shielding member is provided on a surface of said reflecting member. The front lighting apparatus according to claim 1, further comprising compensation means for matching the exit direction of the exit light from the flat part of the second exit surface with the exit light from the inclined part. 27. The method of claim 26, wherein the compensating means comprises a first surface opposite the second exit surface of the light guide and a second surface opposite the first surface, The first surface of the compensating means alternately has an inclined surface substantially parallel to the inclined portion of the second exit surface of the light guide and a flat surface substantially parallel to the flat portion of the second output surface, Is formed in a complementary staircase shape, And the second surface of the compensating means is disposed substantially parallel to the first exit surface of the light guide. 27. The compensation means according to claim 26, wherein, in the compensation means, a region in which the exit light from the inclined portion of the second exit surface enters generally differs from a region in which the exit light from the flat portion of the second exit surface enters each other. A front lighting device having a refractive index. 27. The front lighting apparatus according to claim 26, wherein said compensating means is provided with a diffractive element mainly in a region in which the emitted light from the inclined portion of the second exit surface is incident. 27. The front lighting apparatus according to claim 26, wherein said compensating means is provided with a light shielding member mainly in a region in which the emitted light from the inclined portion of the second exit surface is incident. The front lighting apparatus according to claim 1, further comprising light control means for limiting the expansion of light from the light source between the light source and the incident surface. 32. A front lighting apparatus according to claim 31, wherein said light control means restricts the expansion of light from the light source in a range in which the incident angle of light directly incident from the incident surface to the inclined portion of the second exit surface is larger than the critical angle. Has a light guide disposed in front of the light source and the object to be illuminated, The light guide body has a planar bottom surface, a surface facing the bottom surface, and an incident surface on which light from a light source is incident, The surface is formed in a step shape in which a flat portion substantially parallel to the bottom surface and an inclined portion inclined in the same direction with respect to the flat portion are alternately arranged. The total illumination of the projection to the bottom of the flat portion is larger than the total of the projection to the bottom of the inclined portion. The front lighting apparatus according to claim 1, wherein the sum of the pitch of the flat portion formed on the light guide member and the pitch of the inclined portion decreases as the distance from the incident surface decreases. While having a reflective liquid crystal element having a reflecting plate, A front illumination device according to claim 1 is arranged on a front surface of the reflective liquid crystal element, characterized in that the reflective liquid crystal display device. The liquid crystal device of claim 35, wherein the reflective liquid crystal device has a scanning line, The pitch of the said scanning line and the pitch of the flat part of the 2nd exit surface of a front illumination apparatus are substantially the same, and the flat part is arrange | positioned above a scanning line, The reflection type liquid crystal display device characterized by the above-mentioned. 36. The liquid crystal display of claim 35, wherein the reflective liquid crystal device has a scan line, The sum of the pitch of the flat portion of the second exit surface of the front illumination device and the pitch of the inclined portion is smaller than the pitch of the scan line. 36. The liquid crystal display of claim 35, wherein the reflective liquid crystal device has a scan line, The sum of the pitch of the flat portion of the second emission surface of the front illumination device and the pitch of the inclined portion is larger than the pitch of the scan line. 36. The reflection type liquid crystal display device according to claim 35, wherein the reflection type liquid crystal element has a reflection plate having an uneven portion on its surface. 40. The reflection type liquid crystal display device according to claim 39, wherein the reflection plate is a reflection electrode which serves as a liquid crystal drive electrode for driving the liquid crystal layer of the reflection type liquid crystal element, and is provided adjacent to the liquid crystal layer. 36. The reflective liquid crystal display device according to claim 35, wherein the front lighting device is freely opened and closed with respect to the reflective liquid crystal element. In the reflection type liquid crystal display device which has the front-illumination apparatus of Claim 27 on the front surface of the reflection type liquid crystal element which has a reflecting plate, The compensation means is flexible to a predetermined pressure, A reflection type liquid crystal display device, characterized in that a pair of position detection means for detecting a position to which pressure is applied by contacting each other is provided in each of the compensation means and the second exit surface. The liquid crystal device of claim 42, wherein the reflective liquid crystal device has a scan line, The position detecting means includes a transparent electrode formed on the flat portion of the second exit surface, A reflective liquid crystal display device, wherein a transparent electrode is disposed above the scanning line so that the pitch of the scanning line and the pitch of the transparent electrode are substantially the same. The total projection of the projection to the first exit surface of the flat portion: The total projection of the projection to the first exit surface of the inclined portion is about 20: 1. Front lighting device.