JPH06167689A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To improve the versatility by using the liquid crystal display device for both a projection display and a direct-view display. CONSTITUTION:The liquid crystal display device 31 has a liquid crystal display element 32 which displays an image, and a 1st liquid crystal element 33 and a 2nd liquid crystal element 34 are arranged in the order on the opposite side to the display surface of the element 32. For the projection display, the 1st and 2nd liquid crystal elements 33 and 34 are placed in a light transmission state. For the direct-view display, on the other hand, the 1st liquid crystal element 33 is used as a diffusion plate and the 2nd liquid crystal element 34 is used as a reflection plate. Therefore, the liquid crystal display device 31 is usable for both the projection display and direct-view display and the versatility is greatly improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device,
In particular, the present invention relates to a liquid crystal display device that switches between a projection display using an overhead projector (OHP) or the like and a direct view display.

[0002]

2. Description of the Related Art FIG. 10 is a plan view showing a conventional liquid crystal display device 1 for performing projection display using OHP or the like. The liquid crystal display device 1 has a transmissive region 2. In the transmissive region 2, a liquid crystal display element 4 is disposed which electrically controls the alignment state of liquid crystal molecules and blocks / transmits incident light to perform display. The control of the liquid crystal display element 4 is
The operation is performed by operating the operation unit 3 provided on the liquid crystal display device 1.

FIG. 11 shows the liquid crystal display device 1 and OHP8.
It is a side view for explaining projection display using and. A liquid crystal display element 4 is arranged in a portion corresponding to the transmissive region 2 of the liquid crystal display device 1. In the liquid crystal display element 4, a liquid crystal layer 7 is interposed between transparent substrates 5 and 6. Further, on the surfaces of the substrates 5 and 6 on the liquid crystal layer 7 side, electrodes (not shown) for driving the liquid crystal molecules 7a of the liquid crystal layer 7 and the liquid crystal molecules 7 are formed.
An alignment film for aligning a is formed.

The OHP 8 comprises a light source 9, a housing 10 that covers the light source 9, a reflecting mirror 11, and a projection lens 12. The housing 1 includes the housing 1
A light-transmissive glass plate or the like is provided in a region where the light emitted from the light source 9 installed inside the display unit 0 is emitted, and the liquid crystal display device 1 is mounted on the glass plate. Further, the reflecting mirror 11 is provided on the downstream side in the emission direction of the light emitted from the light source 9, and the liquid crystal display device 1 is provided with the reflecting mirror 11 by adjusting the distance between the reflecting mirror 11 and the mounted liquid crystal display device 1. The focus of the displayed image is adjusted. The light emitted from the light source 9 is selectively transmitted / blocked according to the alignment state of the liquid crystal molecules 7 a of the liquid crystal display device 1, and is reflected by the reflecting mirror 11. The reflected light is enlarged and projected on a screen (not shown) by the projection lens 12 and displayed as an image. The observer sees the screen and recognizes the image.

FIG. 12 is a perspective view showing a conventional direct-view type liquid crystal display device 21 used in a word processor or the like. The liquid crystal display device 21 has a transmissive region 22,
In the transmissive region 22, a display element having the same structure as the liquid crystal display element 4 described above is arranged. In addition, the liquid crystal display device 2
1, a backlight unit 23 for irradiating the display element with light is provided. A light source 24 realized by a fluorescent tube or the like is arranged in the backlight unit 23. The light emitted from the light source 24 is selectively transmitted / blocked by the action of the liquid crystal display element and emitted from the transmissive region 22 as an image, and the observer directly recognizes this emitted light as an image.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the case of performing projection display by using, for example, the liquid crystal display device 1
On the other hand, when performing direct-view display, the liquid crystal display device 21 is used. Thus, conventionally, a display device is selected according to the purpose and a suitable display device is used. However, at least two display devices are required, which causes problems such as high cost and poor versatility.

Further, in order to make up for the drawback that the versatility of such a display device is poor, there has been proposed a liquid crystal display device 51 having a removable illumination unit 53, as shown in FIG. The liquid crystal display device 51 includes the liquid crystal display element 5
2, lighting unit 53, frame 54, and support plate 5
6 and a glass plate 57. The liquid crystal display element 52 is
The display element has the same configuration as the liquid crystal display element 4 described above. A removable lighting unit 53 is attached to the frame 54 on the side opposite to the display surface of the liquid crystal display element 52 by bolts 5.
It is fixed and arranged at 5. On the frame 54, a glass plate 57 having a light transmitting property is provided in a region where the light emitted from the illumination unit 53 is emitted. Further, the frame 54 is provided with a support plate 56 for holding the liquid crystal display device 51 at an appropriate angle with respect to the installation surface.

The illumination unit 53 is detached and used for projection display using OHP or the like, and the illumination unit 53 is attached and used for direct view display. However, even in this case, it is necessary to attach and detach the lighting unit 53 according to the purpose, which causes a problem of inconvenience.

An object of the present invention is to provide a highly versatile liquid crystal display device capable of switching between projection display and direct-view display.

[0010]

SUMMARY OF THE INVENTION According to the present invention, a liquid crystal display element for displaying an image by transmitting / blocking incident light is disposed, and the liquid crystal display element is arranged on the opposite side of the display surface and transmits the incident light. A first liquid crystal element having a transmissive state and a diffused state for diffusing incident light; a transmissive state that is arranged on the opposite side of the first liquid crystal element from the liquid crystal display element and that transmits the incident light; A second liquid crystal element having a reflection state for reflecting light; and a control means for controlling the liquid crystal display element and the first and second liquid crystal elements, wherein the control means is arranged to project the first and second liquid crystal elements. 2 Set the liquid crystal element to the transmissive state,
The liquid crystal display device is characterized in that the first liquid crystal element is set in a diffusing state and the second liquid crystal element is set in a reflecting state during direct-view display.

Further, the liquid crystal display device of the present invention comprises:
The light guide plate is disposed between the liquid crystal element and the second liquid crystal element and guides the incident light to the display surface, and the light source is disposed along the outer end of the light guide plate. The control means turns off the light source, and during direct-view display, the control means turns on the light source.

Further, according to the present invention, a liquid crystal display element for displaying an image by transmitting / blocking incident light, and a transmissive state which is arranged on a side opposite to a display surface of the liquid crystal display element and transmits the incident light, A liquid crystal element having a diffusion state for diffusing incident light, and a reflector plate arranged on the opposite side of the liquid crystal display element with respect to the liquid crystal element, for transmitting or reflecting incident light,
A light guide plate disposed between the liquid crystal element and the reflection plate to guide incident light to a display surface, a light source arranged along an outer end of the light guide plate, the liquid crystal display element, a liquid crystal element, and And a control means for controlling a light source, wherein the control means sets the liquid crystal element in a transmissive state during projection display, turns off the light source, and sets the liquid crystal element in a diffused state during direct-view display, A liquid crystal display device characterized by turning on a light source.

[0013]

According to the present invention, during projection display of the liquid crystal display device, the control means includes the first liquid crystal element arranged on the side opposite to the display surface of the liquid crystal display element, and the liquid crystal display element of the first liquid crystal element. The second liquid crystal element arranged on the opposite side to the second liquid crystal element is set in a transmissive state, and the liquid crystal display element is driven to selectively transmit / block incident light to display an image. When the liquid crystal display device in this state is installed on an enlarged projection display means such as an OHP and light is emitted from the second liquid crystal element side, this incident light passes through the second and first liquid crystal elements and is given to the liquid crystal display element. To be The incident light is selectively transmitted / blocked by the liquid crystal display element and is emitted as an image. The emitted light is incident on the projection lens included in the enlarged projection display means, irradiates a screen or the like, and is enlarged and displayed as an image.

On the other hand, during the direct-view display of the liquid crystal display device, the control means sets the first liquid crystal element in the diffusion state, sets the second liquid crystal element in the reflection state, and drives the liquid crystal display element to make it enter. An image is displayed by selectively transmitting / blocking light. The light incident from the liquid crystal display element is reflected by the second liquid crystal element and given to the first liquid crystal element. The light incident on the first liquid crystal element is diffused and applied to the entire surface of the liquid crystal display element. The liquid crystal display element selectively transmits / blocks incident light and emits light as an image. This emitted light is directly observed by an observer and is recognized as an image.

Therefore, the projection display and the direct-view display can be performed, and the versatility of the liquid crystal display device is significantly improved.

Further, by disposing the light guide plate between the first liquid crystal element and the second liquid crystal element and disposing the light source along the outer end of the light guide plate, the light from the light source is The light is guided to the display surface by the light guide plate arranged between the first liquid crystal element and the second liquid crystal element, reflected by the second liquid crystal element, and given to the first liquid crystal element. Therefore, the utilization efficiency of light is increased, and a brighter display can be realized.

Further, according to the invention, during projection display of the liquid crystal display device, the control means turns off the light source and sets the liquid crystal element arranged on the side opposite to the display surface of the liquid crystal display element to the transmissive state, An image is displayed by driving a liquid crystal display element to selectively transmit / block incident light. The liquid crystal display device in this state is installed on a magnified projection display means such as an OHP, and is arranged on the side opposite to the liquid crystal display element with respect to the liquid crystal element.
When light is emitted from the side of the reflector that can transmit the incident light, the incident light passes through the reflector and the liquid crystal element and is given to the liquid crystal display element. The incident light is selectively transmitted / blocked by the liquid crystal display element and is emitted as an image.
The emitted light is incident on the projection lens included in the enlarged projection display means, irradiates a screen or the like, and is enlarged and displayed as an image.

On the other hand, during the direct-view display of the liquid crystal display device, the control means sets the liquid crystal element in the diffusion state and turns on the light source. Further, the liquid crystal display element is driven to selectively transmit / block incident light to display an image. The light incident from the display surface is reflected by the reflection plate and given to the liquid crystal element. Further, the light from the light source is guided to the display surface by the light guide plate arranged between the liquid crystal element and the reflection plate,
The light is reflected by the reflector and given to the liquid crystal element. The light incident on the liquid crystal element is diffused and applied to the entire surface of the liquid crystal display element. The liquid crystal display element selectively transmits / blocks incident light and emits light as an image. This emitted light is directly observed by an observer and is recognized as an image.

Therefore, it is possible to perform the projection display and the direct-view display, and it is possible to increase the light utilization efficiency, improve the versatility of the liquid crystal display device, and realize a bright display. You can

[0020]

1 is a sectional view showing a schematic structure of a liquid crystal display device 31 which is a first embodiment of the present invention. The liquid crystal display device 31 includes a liquid crystal display element 32, first and second liquid crystal elements 33 and 34, and a housing 36. The liquid crystal display element 32 and the first and second liquid crystal elements 33 and 34 are
They are arranged in this order. The liquid crystal display element 32 has, for example, a nematic liquid crystal interposed between translucent substrates, and the first and second liquid crystal elements 33 and 34 have a dynamic scattering state between the translucent substrates, for example. A liquid crystal and a polymer dispersed liquid crystal are interposed. Projection display and direct-view display are performed by controlling the alignment state of the liquid crystal molecules of these elements 32, 33, and 34.

The housing 36 surrounds the liquid crystal display element 32 and the first and second liquid crystal elements 33 and 34 to protect these members, and is realized by, for example, a synthetic resin. In the housing 36, a top surface side transmission area 37a and a bottom surface side transmission area 37b corresponding to a transmission area 38 through which light from a light source provided in at least the OHP or the like passes.
Is provided with a light-transmitting glass plate or the like.

FIG. 2 is a perspective view showing the outer appearance of the liquid crystal display device 31, and FIG. 3 is a bottom view of the liquid crystal display device 31.
The liquid crystal display device 31 can change the angle with respect to the installation surface depending on the use state, that is, the time of projection display and the time of direct view display. As shown in FIG. 2, when installing at an appropriate angle with respect to the installation surface, the liquid crystal display device 31
Are supported by a support plate 39 formed on the liquid crystal display device 31. On the other hand, when the support plate 39 is directly installed on the installation surface, the support plate 39 is folded and stored on the bottom surface of the liquid crystal display device 31, as shown in FIG.

Further, a sensor 40 is formed on the bottom surface of the liquid crystal display device 31. The sensor 40 is a means for detecting the usage state thereof, and is realized by, for example, an optical sensor or a push button switch, and when the liquid crystal display device 31 is installed on an installation surface such as an OHP, that is, at the time of projection display, for example, an optical sensor. It is turned on when the light from the sensor is cut off or the push button switch is pressed. On the other hand, when it is not installed, that is, at the time of direct-view display, the light of the optical sensor is transmitted, or the push button switch is not pressed and the switch is turned off.

FIG. 4 is a block diagram showing a simple electrical configuration of the liquid crystal display device 31. The liquid crystal display device 31 includes a determination circuit 41, an AC voltage generation circuit 42, and an image signal drive circuit 44. The determination circuit 41 determines the usage state of the liquid crystal display device 31 based on the output from the sensor 40. That is, when the liquid crystal display device 31 is installed on the installation surface and the sensor 40 is on, it is determined that projection display is performed, and the sensor 40 has an angle with respect to the installation surface and the sensor 40 is off. In this case, it is determined that the direct-view display will be performed.

The AC voltage generation circuit 42 switches the operation mode of the connected liquid crystal elements 33 and 34 based on the judgment of the judgment circuit 41. That is, when projection display is performed in the liquid crystal display device 31, an AC voltage that causes the first and second liquid crystal elements 33 and 34 to be in a transmissive state is generated and applied to the elements 33 and 34, respectively. . On the other hand, when the direct-view display is performed on the liquid crystal display device 31,
An AC voltage that causes the first liquid crystal element 33 to function as a diffusion plate and an AC voltage that causes the second liquid crystal element 34 to function as a reflector are applied to the elements 33 and 34, respectively.
The elements 33 and 34 to which the respective AC voltages are applied are controlled based on the AC voltage to which the alignment state of the liquid crystal molecules of the elements 33 and 34 is applied.

The image signal drive circuit 44 drives the liquid crystal display element 32 based on an image signal input from an image signal source (not shown). In the liquid crystal display element 32, the alignment state of the liquid crystal molecules of the element 32 is controlled based on the input image signal.

During projection display of the liquid crystal display device 31, the device 31 is installed on, for example, an OHP prepared in advance, the sensor 40 is turned on, and the determination circuit 41 determines that projection display is to be performed. Then, the AC voltage generating circuit 42 brings the first and second liquid crystal elements 33 and 34 into the transmissive state, respectively.

Therefore, the light emitted from the light source provided in the OHP passes through the bottom surface side transmissive region 37b of the housing 36 and enters the second liquid crystal element 34. Here, since the liquid crystal elements 33 and 34 are in the transmissive state as described above, incident light is incident on these liquid crystal elements 33 and 34.
And then enters the liquid crystal display element 32. Further, in the liquid crystal display element 32, since the alignment state of the liquid crystal molecules is controlled based on the image signal, the light incident on the liquid crystal display element 32 is selectively transmitted / received according to the alignment state of the liquid crystal molecules.
The light is blocked, and the light is emitted from the upper surface side transmission region 37a of the housing 36. The emitted light is enlarged and projected on the screen by a reflecting mirror and a projection lens included in the OHP, and an image is displayed.

On the other hand, during the direct-view display of the liquid crystal display device 31, the sensor 40 is turned off, and the determination circuit 41 determines that the direct-view display is performed. Subsequently, the AC voltage generating circuit 42 uses the first liquid crystal element 33 as a diffusion plate and the second liquid crystal element 34 as a reflection plate.

Therefore, the light incident from the upper surface side transmission region 37a of the housing 36 receives the second light having the function of the reflection plate.
It is reflected by the liquid crystal element 34 and given to the first liquid crystal element 33. The first liquid crystal element 33, which functions as a diffusion plate, diffuses incident light and irradiates the entire surface of the liquid crystal display element 32. In the liquid crystal display element 32, the alignment state of the liquid crystal molecules is controlled based on the image signal, so that the light incident on the liquid crystal display element 32 is selectively transmitted / blocked according to the alignment state of the liquid crystal molecules, The light is emitted from the transmission region 37a on the upper surface side of the housing 36. An observer directly views the emitted light and recognizes it as an image.

As described above, according to the present embodiment, when the sensor 40 detects the usage state of the liquid crystal display device 31 and projection display is performed on the liquid crystal display device 31, the first liquid crystal element 33 and the second liquid crystal element 33 are used. The liquid crystal element 34 and the liquid crystal element 34 are brought into a transmissive state. On the other hand, when the direct-view display is performed, the first liquid crystal element 33 is a diffusion plate and the second liquid crystal element 34 is a reflection plate. Therefore, the liquid crystal display device 31 can realize two types of display, that is, a projection display and a direct-view display, and the versatility of the liquid crystal display device 31 is improved.

FIG. 5 is a sectional view showing a schematic structure of a liquid crystal display device 46 which is a second embodiment of the present invention. In the second embodiment, a light source 35 and a light guide plate 45 are provided in the liquid crystal display device 31 of the first embodiment described above, and a polymer dispersed liquid crystal is used for the first liquid crystal element 33. Further, in the liquid crystal display device 46 of the present embodiment, the reflective plate 47 made of a translucent material is used instead of the second liquid crystal element 34 of the liquid crystal display device 31.

The light source 35 is realized by, for example, a fluorescent tube,
It is provided between the first liquid crystal element 33 and the reflection plate 47 and along the outer end of the light guide plate 45, and is provided as a so-called edge light system. The light guide plate 45 is realized by, for example, translucent glass, and is provided between the liquid crystal element 33 and the reflection plate 47 in a region corresponding to the transmission region 38. Further, in the liquid crystal display device 46, the refractive index n1 of the substrate of the liquid crystal display element 32 and the refractive index n of the light guide plate 45.
2 and the refractive index n3 of the reflection plate 47 are n1 <n2 <n
It is adjusted to be 3. The refractive index n can be arbitrarily adjusted by, for example, an ion implantation method.

FIG. 6 is a diagram for explaining the operation of the first liquid crystal element 33 in the liquid crystal display device 46 during the direct-view display and the projection display. 6 (1) shows the time of direct-view display, and FIG. 6 (2) shows the time of projection display. The polymer-dispersed liquid crystal used in the first liquid crystal element 33 includes a polymer 33b and a liquid crystal 33a.
Are formed by being dispersed to scatter / non-scatter light. That is, as shown in FIG. 6 (1), when no voltage is applied, the alignment state of the liquid crystal molecules is non-uniform and in a scattering state, and as shown in FIG. The molecules are oriented and are in a non-scattering state (transparent). This 2
Light is diffused or transmitted by controlling two states.

FIG. 7 is a block diagram showing a simple electrical configuration of the liquid crystal display device 46. In the block diagram shown in FIG. 7, the light source control circuit 43 is connected to the determination circuit 41 of the block diagram shown in FIG. Light source control circuit 43
Controls the light source 35 connected to the circuit 43 based on the judgment of the judgment circuit 41. That is, the liquid crystal display device 4
When 6 is used for projection display, the light source 35 is turned off, and when the liquid crystal display device 46 performs direct-view display, the light source 35 is turned on to emit light.

No voltage is applied to the liquid crystal element 33 when the direct-view display is performed. Upper surface side transparent region 3 of the housing 36
The light incident from 7 a is reflected by the reflection plate 47, passes through the light guide plate 45, and is given to the liquid crystal element 33. Further, the light emitted from the light source 35 is guided to the transmissive region 38 by the light guide plate 45, reflected by the reflection plate 47 having the refractive index n3 larger than the refractive index n2 of the light guide plate 45, and then the liquid crystal element 33.
Given to. Since the liquid crystal element 33 is in the scattering state,
The incident light is diffused and the entire surface of the liquid crystal display element 32 is irradiated almost uniformly. The light emitted from the liquid crystal display element 32 is selectively transmitted / blocked by the action of the liquid crystal display element 32,
It is recognized as an image by an observer.

On the other hand, when performing projection display, the liquid crystal element 33
A voltage is applied to. Light emitted from a light source such as an OHP enters from the bottom surface side transmissive region 37b of the housing 36, passes through the translucent reflection plate 47 and the light guide plate 45, and enters the liquid crystal element 33. Since the liquid crystal element 33 is in a non-scattering state (transparent), the incident light is transmitted and given to the liquid crystal display element 32. The light emitted from the liquid crystal display element 32 is
By the action of the liquid crystal display element 32, the light is selectively transmitted / blocked and enlarged and projected on the screen to display an image.

As described above, according to this embodiment, at the time of direct-view display, the first liquid crystal element 33 is set in the scattering state and the light source 35 is turned on. On the other hand, at the time of projection display, the first liquid crystal element 33 is set to the non-scattering state (transparent), and the light source 35 is turned off. Therefore, in the liquid crystal display device 46, it is possible to realize two types of display, that is, the direct-view display and the projection display, and it is possible to improve the light utilization efficiency, and therefore, the liquid crystal display device 31 of the first embodiment can be used. In comparison, the direct-view display can be brightened.

Next, a third embodiment of the present invention will be described. In the third embodiment, the light source 35 and the light guide plate 45 are provided in the liquid crystal display device 31 of the first embodiment described above similarly to the second embodiment, and the second liquid crystal element 34 has the dynamic scattering state. It uses a liquid crystal.

FIG. 8 shows the substrate 34a of the second liquid crystal element 34,
It is sectional drawing which shows the transparent electrode 49 formed in 34b.
The transparent electrode 49 is, for example, ITO (Indium Tin Oxide).
A plurality of strip-shaped electrodes made of, and the electrode spacing d is formed so as to become closer as the distance from the light source 35 increases.

FIG. 9 is a diagram for explaining the operation of the second liquid crystal element 34 in the liquid crystal display device 48 during projection display and direct view display. 9 (1) shows the time of projection display, and FIG. 9 (2) shows the time of direct view. The liquid crystal molecules 34a of the second liquid crystal element 34 are vertically aligned when no voltage is applied, and allow incident light to pass therethrough. Further, when a predetermined threshold voltage is applied, the alignment of the liquid crystal molecules 34a is disturbed, resulting in a turbulent state and becoming cloudy. Therefore, it becomes possible to reflect the incident light. Light is transmitted or reflected by controlling these two states.

When projection display is performed, no voltage is applied to the liquid crystal element 34. Light emitted from a light source such as an OHP enters from the bottom surface side transmissive region 37 b of the housing 36 and enters the liquid crystal element 34. The liquid crystal molecules 34a of the liquid crystal element 34 are vertically aligned and allow incident light to pass therethrough. The light that has passed through the liquid crystal element 34 passes through the light guide plate 45, further passes through the first liquid crystal element 33 that is set to the transmissive state, and is provided to the liquid crystal display element 32. Liquid crystal display element 3
The light emitted from 2 is selectively transmitted / blocked by the action of the liquid crystal display element 32, and is enlarged and projected on the screen to display an image.

On the other hand, when performing direct-view display, the liquid crystal element 34 is used.
Is applied with a predetermined threshold voltage. The light incident from the upper surface side transmissive region 37 a of the housing 36 is reflected by the liquid crystal element 34 which is in a turbulent state and becomes cloudy, passes through the light guide plate 45, and is given to the liquid crystal element 33. Further, the light emitted from the light source 35 is guided to the transmissive region 38 by the light guide plate 45, reflected by the liquid crystal element 34, and given to the liquid crystal element 33. Furthermore, the housing 3
Part of the light incident from the bottom surface side transmission region 37 b of 6 is scattered by the liquid crystal element 34, passes through the light guide plate 45, and is provided to the liquid crystal element 33. The liquid crystal element 33 in the diffused state diffuses the incident light and gives it to the liquid crystal display element 32. The light emitted from the liquid crystal display element 32 is selectively transmitted / blocked by the action of the liquid crystal display element 32, and is recognized as an image by an observer.

The change in the alignment state of the liquid crystal molecules 34a by applying a voltage to the liquid crystal element 34 occurs only in the portion where the transparent electrode 49 shown in FIG. 8 is formed. The liquid crystal molecules 34a in the portion where the transparent electrode 49 is not formed are in the same state as when no voltage is applied, that is, in the vertical alignment state,
Transmits incident light. Although the intensity of light becomes weaker as the distance from the light source 35 increases, the transparent electrode 49 is formed such that the electrode interval d becomes closer as the distance from the light source 35 increases as described above. The light is reflected, and the liquid crystal display element 32
It becomes possible to irradiate the entire surface almost uniformly.

As described above, according to this embodiment, the first and second liquid crystal elements 33 and 34 are set in the transmissive state during projection display. On the other hand, at the time of direct-view display, the first liquid crystal element 33 is a diffusion plate and the second liquid crystal element 34 is a reflection plate. In addition, the electrode interval d of the transparent electrode 49 formed on the second liquid crystal element 34.
Are adjusted and formed. Therefore, the liquid crystal display device 4
In 8, it is possible to realize two types of display, that is, a direct-view display and a projection display, and it is possible to irradiate light uniformly, and it is possible to make the direct-view display bright and uniform. Become.

[0046]

As described above, according to the present invention, the operation mode of the first liquid crystal element and the second liquid crystal element of the liquid crystal display device can be switched according to the display type of the liquid crystal display device. Therefore, it becomes possible to perform projection display and direct view display,
The versatility and convenience of the liquid crystal display device is significantly improved.
Furthermore, since the light guide plate and the light source are arranged, it is possible to improve the light utilization efficiency and realize a bright display.

Further, according to the present invention, the operation mode of the liquid crystal element can be switched according to the display type of the liquid crystal display device,
A reflector is provided that can reflect or transmit incident light. Therefore, it becomes possible to perform projection display and direct-view display, which improves the versatility and convenience of the liquid crystal display device, and also enables bright display.

[Brief description of drawings]

FIG. 1 is a liquid crystal display device 31 which is a first embodiment of the present invention.
3 is a cross-sectional view showing the schematic configuration of FIG.

2 is a perspective view showing an appearance of a liquid crystal display device 31. FIG.

3 is a bottom view of the liquid crystal display device 31. FIG.

FIG. 4 is a block diagram showing a simple electrical configuration of a liquid crystal display device 31.

FIG. 5 is a liquid crystal display device 46 according to a second embodiment of the present invention.
3 is a cross-sectional view showing the schematic configuration of FIG.

FIG. 6 is a diagram for explaining the operation of the first liquid crystal element 33 of the liquid crystal display device 46.

7 is a block diagram showing a simple electrical configuration of a liquid crystal display device 46. FIG.

FIG. 8 is a liquid crystal display device 48 according to a third embodiment of the present invention.
9 is a cross-sectional view showing a transparent electrode 49 formed on the second liquid crystal element 34 of FIG.

FIG. 9 is a diagram for explaining the operation of the second liquid crystal element 34 of the liquid crystal display device 48.

FIG. 10 is a plan view showing a conventional liquid crystal display device 1.

FIG. 11 is a side view for explaining projection display using the liquid crystal display device 1 and the OHP 8.

FIG. 12 is a perspective view showing a conventional direct-viewing type liquid crystal display device 21.

FIG. 13 is a side view showing a conventional liquid crystal display device 51.

[Explanation of reference numerals] 31, 46, 48 Liquid crystal display device 32 Liquid crystal display element 33 First liquid crystal element 34 Second liquid crystal element 35 Light source 41 Judgment circuit 42 AC voltage generation circuit 43 Light source control circuit 44 Image signal drive circuit 45 Light guide plate 47 a reflector

Claims (3)

[Claims] 1. A liquid crystal display element that transmits / blocks incident light to display an image, a transmissive state that is disposed on a side opposite to a display surface of the liquid crystal display element and that transmits the incident light, and diffuses the incident light. A first liquid crystal element having a diffusing state, a transmissive state that is disposed on the opposite side of the first liquid crystal element from the liquid crystal display element, and that transmits incident light, and a reflective state that reflects incident light. A second liquid crystal element having the liquid crystal display element, and a control means for controlling the liquid crystal display element and the first and second liquid crystal elements, wherein the control means is configured to display the first and second liquid crystal elements during projection display.
A liquid crystal display device, wherein the liquid crystal element is set to a transmissive state, and the first liquid crystal element is set to a diffusing state and the second liquid crystal element is set to a reflective state during direct-view display. 2. A light guide plate which is arranged between the first liquid crystal element and the second liquid crystal element and guides incident light to a display surface, and a light source which is arranged along an outer end of the light guide plate. 2. The liquid crystal display device according to claim 1, wherein the control means turns off the light source during the projection display, and the control means turns on the light source during the direct-view display. 3. A liquid crystal display element that transmits / blocks incident light to display an image, a transmissive state that is disposed on the opposite side of the display surface of the liquid crystal display element and that transmits the incident light, and diffuses the incident light. A liquid crystal element having a diffusing state, a reflection plate arranged on the opposite side of the liquid crystal element from the liquid crystal display element, and a reflection plate transmitting or reflecting incident light, and arranged between the liquid crystal element and the reflection plate. And a light guide plate that guides incident light to a display surface, a light source that is arranged along an outer end of the light guide plate, and a control unit that controls the liquid crystal display element, the liquid crystal element, and the light source, The control means sets the liquid crystal element to a transmissive state and turns off the light source during projection display, and sets the liquid crystal element to a diffused state and turns on the light source during direct-view display. apparatus.