JPH117253A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for preventing the reduction of visibility due to external light, as for a display body with a display screen which is irradiated with the external light. SOLUTION: The display body 11 is attached on the surface side of the main body part 10, and the display screen 11a is installed on the surface of the body 11. Linking members 12 and 13 rotatably and mutually connected by a hinge connection are connected to the surface side of the main body part 10 in a two-step state, and a light control plate 14 is rotatably attached to the leading end part of the linking member 13. The light control plate 14 is formed to a flat rectangular frame, and a light control filter 15 is installed inside the frame. The light control filter 15 is constituted by thinly forming an extinction layer 15b formed of a Cr vapor-deposited film on the surface of a transparent glass plate 15a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a display device, and more particularly to a structure for improving visibility suitable for use in a reflection type liquid crystal display.

[0002]

2. Description of the Related Art Conventionally, in a liquid crystal display device, a reflection surface is provided inside a liquid crystal display, and light incident from the outside passes through a liquid crystal layer and is reflected by the reflection surface, and then passes through the liquid crystal layer again. There are reflective liquid crystal displays configured to emit light.

In a reflection type liquid crystal display device, various liquid crystal layers are held between a light-transmitting substrate disposed on the light incident side and a substrate disposed on the opposite side thereof. A reflection surface is formed on the opposite side. The reflection surface may be formed on the front surface or the back surface of the opposite substrate, and the pixel electrode formed on the inner surface of the opposite substrate may be formed of a metal electrode such as Cr having a high reflectance. May be formed also as a pixel electrode.

According to the reflection type liquid crystal display device, the display can be visually recognized by reflection of external light.
There is an advantage that a light source is not required and power consumption of the device can be reduced. On the other hand, the above-mentioned reflective liquid crystal display device has a drawback that the display is generally dark because the display can be viewed with light generated by the reflection of external light. To overcome this shortcoming,
Various liquid crystal display devices using a scattering mode capable of displaying without using a polarizing plate have been developed. These liquid crystal display devices generally perform display by switching between a state in which light is scattered by the liquid crystal layer and a state in which the liquid crystal layer is transparent, so that it is not necessary to use a polarizing plate. There is an effect that the display can be brightened.

[0005]

By the way, in a reflection type liquid crystal display device having a dark display, direct light from a light source enters eyes and the reflection of a background becomes remarkable due to reflection of external light. However, there is a problem that the visibility of the display is significantly impaired. On the other hand, in order to reduce the reflection of external light, the reflectance of the reflection surface and the transmittance of the liquid crystal layer must be reduced, and thus there is a problem that the brightness and contrast of the display are reduced.

In particular, as described above, in a liquid crystal display using a scattering mode without using a polarizing plate, the brightness of display can be ensured, but when the liquid crystal layer is in a light transmitting state, external light is reflected as it is. Therefore, there is a problem that the visibility is further reduced, such as being confused by the direct light or making the display difficult to see due to the reflection of the background.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a novel display device having a display surface to which external light is irradiated, for preventing a decrease in visibility due to external light. It is to provide the structure of.

[0008]

In order to solve the above-mentioned problem, the present invention provides a light control means which is capable of adjusting the position above a display, and irradiates a display surface of the display with light. Is characterized in that the light amount or direction is adjusted by the light control means.

According to this means, the light control means capable of adjusting the position is provided above the display surface so that the external light is applied to the display surface through the light control means. By adjusting with respect to the main viewing direction of the user (for example, the extending direction of a straight line connecting the user's eyes and the center of the display surface), reflection of external light can be reduced, and direct illumination can be prevented. Illusions due to reflection and reflection of the background can be prevented.

Here, the display may be a reflective liquid crystal display.

According to this means, in the reflection type liquid crystal display, the display can be visually recognized by the external light. Therefore, by controlling the external light, the brightness of the display and the reflection of the external light can be reduced. It can be optimized by balancing, which is particularly effective for improving visibility.

The light control means may be a neutral density filter for reducing the amount of light applied to the display surface.

According to this means, the amount of external light can be limited by the neutral density filter to adjust the amount of reflected external light.

Further, the light control means comprises a transmission filter, and the transmission filter is formed with a light-shielding surface for partially shielding at least visible light, and the light-shielding surface is provided on a surface of one substrate of the display. It is configured to be arranged so as to intersect.

According to this means, by passing a plurality of light-shielding surfaces through transmission filters provided at predetermined intervals, it is possible to particularly effectively reduce dazzling and background reflection caused by direct reflection of illumination caused by external light. be able to.

In this case, it is preferable that the light control means is formed of a light transmitting body including a light shielding layer forming the light shielding surface.

According to this means, since the light modulation filter is constituted by the light transmitting body in which the light shielding layer is included,
Deterioration and damage of the light shielding layer can be prevented.

Further, the light control means is composed of a light transmitting body having a periodic surface unevenness structure, and the light shielding surface is provided on a surface portion forming a part of the surface unevenness structure. Is preferred.

According to this means, since the light-shielding layer is formed on the surface portion of the uneven surface structure formed on the light transmitting body, the light control filter can be formed easily and at low cost.

In this case, the surface uneven structure of the light transmitting body may be formed on either the incident side surface or the opposite side surface of the light transmitting body.

Further, it is desirable that the display is a reflection type liquid crystal display having a polymer dispersed type composite liquid crystal layer.

According to this means, by forming the polymer-dispersed composite liquid crystal layer, the display can be performed without using a polarizing plate, so that the display can be brightened. Since visibility of external light in the light transmitting state of the liquid crystal layer can be prevented, visibility can be greatly improved.

In this case, it is particularly desirable that the light-shielding surface has a black color.

According to this means, since the light-shielding surface is black, the display in the light transmitting state of the liquid crystal layer can be blackened, so that the display contrast can be enhanced.

[0025]

Next, an embodiment according to the present invention will be described with reference to the accompanying drawings. FIG. 1 schematically shows the entire structure of the display device according to the present invention. A display body 11 is attached to the front surface of the main body 10, and a display surface 11a is provided on the front surface. As the display 11, various display devices such as a liquid crystal display, a CRT (cathode tube), and a plasma display described below can be used.

Link members 12 and 13 rotatably connected to each other by a hinge are connected to the front surface of the main body 10 in two steps. Mounted as possible. Light control board 14
Is configured to be disposed above the display surface 11a by drawing the link members 12, 13 upward, as shown in the figure.

The light control plate 14 is formed in the shape of a flat rectangular frame, and a light control filter 15 indicated by a dotted line is attached inside the light control plate 14. This light control filter 15
As shown in FIG. 2, a thin dimming layer 15b made of a deposited Cr film is formed on the surface of a transparent glass plate 15a. The light-attenuating layer 15b is not limited to a metal-deposited film as long as it can partially reduce the amount of visible light, and various kinds of thin films including colored pigments and dyes can be used.

The light control plate 14 is stored on the surface of the main body 10 by folding the link members 12 and 13 as shown by a dashed line in FIG. Here, in the stored state, by configuring the light control plate 14 to completely cover the display surface 11a, the light control plate 14 can have a function as a protective cover for the display surface 11a.

In this embodiment, the amount of external light can be controlled by disposing the light control plate 14 above the display surface and adjusting the position thereof.
1a can be adjusted to the state that is most visible.

FIG. 3 shows a structure of a different light control filter 25 which can be used in place of the light control filter 15 described above. The light control filter 25 has a light modulating layer 25c made of a transparent resin sandwiched between transparent films 25a and 25b made of polycarbonate. A band-shaped light shielding layer 25d made of a black pigment resist is provided inside the light modulating layer 25c. It is enclosed. The light-shielding layer 25d is configured to absorb visible light, and is arranged at equal intervals in a direction substantially orthogonal to the lamination surface or in a direction inclined to some extent from the orthogonal direction.

The light shielding layer 25d has a thickness of, for example, 100 μm,
The arrangement period is about 141 μm, and its width is
Light control filter 25 having a thickness of about 0.87 to 1.3 mm
The surface of the display device is configured to receive external light in an incident direction that is a source of reflected light that is reflected substantially parallel to a main line of sight of a user set in advance in the display device illustrated in FIG. The direction is set to be at least partially dimmed. The cycle of the light-shielding layer 25d is not limited to the above value, but is preferably formed with a cycle of 0.5 mm or less so that stripes due to the light-shielding layer 25d are not visually noticeable when viewed directly. The transparent film 25a of the light shielding layer 25d,
The angle of the surface 25b to the surface is preferably in the range of 45 to 90 degrees. In the present embodiment, the light shielding layer 25d is
The transparent films 25a and 25b are formed so as to be inclined by about 72 degrees with respect to the surface.

According to the light control filter 25, light parallel to the surface of the light shielding layer 25d is transmitted as it is, but light in the direction intersecting with the surface of the light shielding layer 25d is at least partially blocked by the light shielding layer 25d. The light in the blocked portion does not reach the display surface 11a. Therefore, the light shielding layer 25
By adjusting the angle so as to at least partially diminish the external light that is the source of the reflected light reflected in the direction of the user's line of sight, the reflection of the external light on the display surface 11a is reduced. The visibility of the body 11 can be improved.

The color tone of the light shielding layer 25d is not limited to black, but is preferably black as described above in order to prevent coloring on the display surface. Also, the light shielding layer 25
d does not need to completely absorb the external light. For example, the light-shielding layer 25d itself has a light-transmitting property, but may function as a light-attenuating filter that can reduce the amount of transmitted light. .

The light control filter 25 includes a light shielding layer 25
Since d is included in the inside, there is an advantage that deformation and damage of the light-shielding layer 25d are less likely to occur, and the durability is high.

FIG. 4 shows a further different light control filter 35.
FIG. This light control filter 35
A transparent member 35a which is formed by molding an acrylic resin or the like and has a periodic surface uneven structure having first and second surface portions 35a-1 and 35a-2 alternately formed in a belt shape on the surface.
And a light-shielding layer 3 formed by coating a resin layer containing a black pigment on the surface of the first surface portion 35a-1.
5b.

In this light control filter 35, the light shielding layer 35
b has substantially the same effect as the light-shielding layer 25d of the light control filter 25 shown in FIG. 3, and the same effect can be obtained.
Since the light control filter 35 can be formed simply by coating the light shielding layer 35b on a part of the surface thereof after forming the transparent member 35a and coating it by other methods, it is relatively easy and inexpensive to manufacture. Can be.

FIG. 5 shows a specific structure of a reflective liquid crystal display as an example of the display 11 that can be used in the above embodiment. In this liquid crystal display, a transparent electrode 41 made of ITO (indium tin oxide) or the like is attached on the inner surface of the glass substrate 40 on the light incident side, and an alignment film is formed on the surface of the transparent electrode 41. 42 is applied and rubbed in a predetermined direction.

On the other hand, on the inner surface of the glass substrate 50 facing the glass substrate 40, a reflective electrode layer 5 made of a metal film such as aluminum or chromium is formed by sputtering or vapor deposition.
1 is formed. On the surface of the reflective electrode layer 51, an alignment film 52 similar to the above-described alignment film 52 is formed.

The glass substrate 40 and the glass substrate 50 as described above are pressure-bonded via a sealing material (not shown), and a predetermined gap is formed between the substrates by a known spacer or the like. Then, the liquid crystal layer 60 is injected into this gap.
As the liquid crystal layer 60, various known liquid crystals can be injected. In the present embodiment, a polymer-dispersed composite liquid crystal layer is used as the liquid crystal layer 60. This composite liquid crystal layer
For example, a solution in which a photocurable polymer monomer and a predetermined liquid crystal are mixed and infused is injected between the substrates, and then irradiated with light through the substrate to photopolymerize the polymer monomer, thereby polymerizing the polymerized polymer. It can be formed by dispersing particles in a liquid crystal. The polymer particles and liquid crystal molecules thus formed are normally aligned together in the rubbing direction of the alignment film when no electric field is applied.

In the polymer dispersed type composite liquid crystal layer, since the liquid crystal molecules have dielectric anisotropy and refractive index anisotropy, the refractive index of the polymer particles and the refractive index of the liquid crystal molecules are different. The display state is changed by making use of the fact that the values become substantially equal or different values depending on whether or not an electric field is applied. For example, when no electric field is applied, the aligned polymer particles and liquid crystal molecules are set to have substantially the same refractive index with respect to light entering and exiting in a direction perpendicular to the substrate surface. When the liquid crystal molecules change their orientation in the direction of the electric field, if the polymer particles and the liquid crystal molecules are set to have different refractive indexes, the liquid crystal layer will be in a light transmitting state when no electric field is applied, and will be in a light transmitting state when an electric field is applied. Is in a light scattering state.

When the liquid crystal layer 60 is in a light transmitting state,
External light incident from above the glass substrate 40 in the figure is transmitted through the liquid crystal layer 60, reflected on the surface of the reflective electrode layer 51, returned to the surface side as it is, and visually recognized by the user. However, in the present embodiment, the light control filters 15, 25,
Since external light is reduced by 35, dazzling due to direct reflection of external light and reflection of the background can be prevented.

In the case where the light control filters 25 and 35 are used, the light incident on the light-shielding layers 25d and 35b becomes the source of reflected light that is reflected in substantially the same direction as the main line of sight of the user. The external light provided is the light shielding layers 25d and 35b.
At least a part of the light is shielded or dimmed, so that the directly reflected light of the external light does not reach the user's eyes as it is. Thus, the light shielding layers 25d, 35
Since part of the external light is dimmed or blocked by b, the reflected light is only partially visible to the user. Reflection can be reliably prevented.

In particular, since the polymer-dispersed liquid crystal layer is controlled between a light scattering state and a light transmitting state, a bright black and white display can be obtained. However, conventionally, when the liquid crystal layer is in a light transmitting state, the light directly reflected by the reflective electrode layer 51 is visually recognized. Therefore, when the reflectivity of the reflective electrode layer 51 is increased, the reflection of the external light becomes a mirror surface. There has been a dilemma that the remarkable and black color cannot be obtained and sufficient brightness cannot be obtained when the reflectance of the reflective electrode layer 51 is lowered.

In this embodiment, the light shielding layers 25d, 3d
When the liquid crystal layer 5b is formed in black, the display surface is blackened when the liquid crystal layer is in a light transmitting state, so that the display contrast can be increased.

The inclination angle of the light-shielding layer is set in advance according to the relationship between the liquid crystal display and the main line of sight of the user in accordance with the device in which the liquid crystal display is installed, the mode of use, and the like.
That is, the light-shielding layer is set in advance so as to be inclined with respect to the incident angle of the external light, which is the source of the directly reflected light traveling in the main line of sight of the user, to the light control plate 14, or
The angle of the light control plate 14 shown in FIG. Therefore, if the main viewing direction of the user is a direction having an angle of 45 degrees with respect to the display surface 11a, the light shielding layer 25
The surfaces of d and 35b are set to have an inclination angle other than the angle of 45 degrees with respect to the display surface 11a, or the angle of the light control plate 14 is adjusted.

It should be noted that the light-shielding layer can be configured to be adjustable to an appropriate inclination angle by a connection mechanism similar to that of the blind.

[0047]

As described above, according to the present invention, the following effects can be obtained.

According to the first aspect, the light control means capable of adjusting the position is provided above the display surface so that the external light is applied to the display surface through the light control means. Is adjusted for the main viewing direction of the user, reflection of external light can be reduced, and dazzling due to direct reflection of illumination and reflection of a background can be prevented.

According to the second aspect, in the reflection type liquid crystal display, since the display can be visually recognized by external light, by controlling the external light, the brightness of the display and the reflection of the external light can be reduced. Can be optimized by balancing, which is particularly effective in improving visibility.

According to the third aspect, the amount of external light can be limited by the neutral density filter to adjust the amount of external light reflected.

According to the fourth aspect, by passing the plurality of light-shielding surfaces through transmission filters provided at predetermined intervals, it is possible to particularly effectively reduce dazzling and background reflection caused by direct reflection of illumination caused by external light. can do.

According to the fifth aspect, since the light modulation filter is constituted by the light transmitting body in which the light shielding layer is included,
Deterioration and damage of the light shielding layer can be prevented.

According to the sixth aspect, since the light-shielding layer is formed on the surface of the surface uneven structure formed on the light transmitting body, the light modulation filter can be easily and inexpensively formed.

According to the seventh aspect, by forming the polymer-dispersed composite liquid crystal layer, the display can be performed without using a polarizing plate, so that the display can be brightened. Since the reflection of external light in the light transmission state of the liquid crystal layer can be prevented, the visibility can be greatly improved.

According to the eighth aspect, since the light-shielding surface is black, the display in the light transmitting state of the liquid crystal layer can be blackened, so that the display contrast can be enhanced.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing a schematic overall structure of an embodiment of a display device according to the present invention.

FIG. 2 is an enlarged cross-sectional view illustrating a structure of a light control filter according to the first embodiment.

FIG. 3 is an enlarged cross-sectional view showing a structure of a different light control filter applicable to the embodiment.

FIG. 4 is an enlarged cross-sectional view showing the structure of still another light control filter that can be applied to the embodiment.

FIG. 5 is an enlarged cross-sectional view showing the structure of a reflective liquid crystal display having a polymer-dispersed liquid crystal layer as an example of a display applicable to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Main body part 11 Display body 11a Display surface 12, 13 Link member 14 Light control plate 15, 25, 35 Light control filter 25d, 35b Light shielding layer

Claims (8)

[Claims] 1. A light control means capable of positioning and adjusting is provided above a display body, and the amount of light or direction of light applied to a display surface of the display body is adjusted by the light control means. Display device. 2. The display device according to claim 1, wherein the display is a reflective liquid crystal display. 3. The display device according to claim 1, wherein the light control means is a neutral density filter for reducing the amount of light applied to the display surface. 4. The light control means according to claim 1, wherein the light control means comprises a transmission filter, and the transmission filter is formed with a light shielding surface for partially shielding at least visible light. A display device, which is disposed so as to intersect with a surface of one substrate of a display body. 5. The light control device according to claim 4, wherein:
A display device comprising a light transmitting body including a light shielding layer that forms the light shielding surface. 6. The light control unit according to claim 4, wherein:
A display device comprising a light-transmitting body having a periodic surface unevenness structure, wherein the light-shielding surface is provided on a surface portion forming a part of the surface unevenness structure. 7. The display device according to claim 3, wherein the display is a reflective liquid crystal display having a polymer dispersed composite liquid crystal layer. 8. The display device according to claim 7, wherein the light-shielding surface has a black color.