JP2003215562A - Liquid crystal device and projector using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent thermal deterioration by efficiently radiating the heat of polarizing plates so as to suppress temperature rise. <P>SOLUTION: The polarizing plates 131R, 131G and 131B emit the incident light of a prescribed polarized component to liquid crystal panels 130R, 130G and 130B. The polarizing plates 131R, 131G and 131B are irradiated with reflected light from the liquid crystal panels 130R, 130G and 130B. However, metallic films are vapor-deposited to the emitting surface sides of the polarizing plates 131R, 131G and 131B, and heat generated at the polarizing plates 131R, 131G and 131B is radiated from the metallic films via radiation panels 136R, 136G and 136B. Thus, temperature rise of the polarizing plates 131R, 131G and 131B is suppressed to prevent thermal deterioration. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal device suitable for use with a liquid crystal panel which receives a light beam having a large amount of light, and a projection device using the same.

[0002]

2. Description of the Related Art A liquid crystal panel used as a light valve is constructed by enclosing a liquid crystal between two substrates such as a glass substrate and a quartz substrate. In such a liquid crystal light valve, for example, a thin film transistor (Thin Fil
m Transistor (hereinafter referred to as TFT) and other active elements are arranged in a matrix and opposite electrodes are arranged on the other substrate, and the optical characteristics of the liquid crystal layer sealed between both substrates are changed according to the image signal. By doing so, image display is enabled.

That is, an image signal is supplied to the pixel electrodes (ITO) arranged in a matrix by the TFT elements, and a voltage based on the image signal is applied to the liquid crystal layer between the pixel electrode and the counter electrode to generate liquid crystal molecules. Change the array. As a result, the transmittance of the pixel is changed, and the light passing through the pixel electrode and the liquid crystal layer is changed according to the image signal to display an image.

In order to regulate the alignment of liquid crystal molecules when no voltage is applied, an alignment film is formed on the surface of one substrate (active matrix substrate (also referred to as element substrate)) and the other substrate (counter substrate) in contact with the liquid crystal layer. Are formed, and the alignment film is subjected to rubbing treatment. By the rubbing treatment, liquid crystal molecules when no voltage is applied are arranged in the rubbing direction. For example, if a rubbing process in which the element substrate and the counter substrate are twisted by 90 degrees is performed,
The liquid crystal molecules continuously change their orientation in the liquid crystal panel and are arranged in directions different by 90 degrees between the two substrates.

Polarizing plates are provided on the front and back surfaces of the liquid crystal panel to allow only a predetermined polarization component of incident light to pass through. In the normally white mode, the polarization axes of the polarizing plates on the front surface and the rear surface of the liquid crystal panel are different by 90 degrees so that they are aligned with the rubbing direction of the substrate. Then, the light incident through the polarizing plate on the back surface of the liquid crystal panel is rotated by 90 degrees according to the arrangement of the liquid crystal molecules in the liquid crystal layer when no voltage is applied, and is emitted from the front surface of the liquid crystal panel through the polarizing plate.
As a result, white display is performed.

When a voltage is applied to the liquid crystal, the alignment direction of the liquid crystal changes, rotation of the liquid crystal in the liquid crystal panel in the vibration direction of the light is restricted, and the light emitted from the front surface of the liquid crystal panel is absorbed by the polarizing plate. An image is displayed by applying a voltage according to the image signal to the liquid crystal and transmitting light with a transmittance according to the image signal.

In order to improve the light utilization efficiency,
Usually, a polarization beam splitter is provided on the input surface side of the polarizing plate so that only the polarization component in the transmission axis direction of the polarizing plate is incident on the polarizing plate.

The TFT substrate on which the TFTs are arranged and the counter substrate arranged to face the TFT substrate are manufactured separately.
After both substrates are bonded with high precision in the panel assembly process, liquid crystal is sealed.

In the panel assembling process, first, an alignment film is formed on the facing surfaces of the TFT substrate and the counter substrate manufactured in each substrate process, that is, on the surfaces of the counter substrate and the liquid crystal layer of the TFT substrate in contact with each other. Then, a rubbing process is performed. Next, a seal portion serving as an adhesive is formed on the edge of one of the substrates. The TFT substrate and the counter substrate are attached to each other using the seal portion, and pressure-bonded and cured while performing alignment. A notch is provided in a part of the seal portion, and the liquid crystal is sealed through this notch.

A liquid crystal panel may be used as a light valve for a projector. In the projector, the image on the screen of the liquid crystal panel is enlarged and projected on the screen. Therefore, when dust adheres to the screen of the liquid crystal panel, the image quality of the displayed image is significantly deteriorated due to the influence of dust. Therefore, in order to reduce the influence of dust and the like, dustproof glass is attached to the incident surface and the exit surface of the liquid crystal panel, and the dustproof glass and the liquid crystal panel are stacked and housed in a case.

[0011]

By the way, in the projector, higher brightness is promoted. As the brightness increases, the heat generated in the liquid crystal panel and the like also increases.
Therefore, various improvements have been made to improve the light resistance of the liquid crystal panel and prevent thermal deterioration. For example, a method may be adopted in which chromium, which has been frequently used as a material for a black stripe of a substrate (opposing substrate) on the incident side of a liquid crystal panel, is changed to aluminum.

Chromium partially absorbs light energy to raise the panel temperature, whereas aluminum has a high light reflectance and prevents incident light from being reflected to raise the panel temperature. You can This makes it possible to extend the panel life.

However, there is a problem that the light diffusedly reflected by aluminum is irradiated on the emission side surface of the polarizing plate arranged on the incident surface side of the liquid crystal panel, and the temperature of the polarizing plate rises to cause thermal deterioration. It was

Since only the polarized component in the transmission axis direction is incident from the polarization beam splitter on the incident side of the polarizing plate,
There is no problem of thermal deterioration due to incident light.

The present invention has been made in view of the above problems, and provides a liquid crystal device capable of preventing the polarizing plate from being thermally deteriorated by reflected light from the liquid crystal panel, and a projection device using the same. The purpose is to do.

[0016]

A liquid crystal device according to the present invention is provided so as to face an incident surface of a liquid crystal panel and emits only a predetermined polarization component of incident light to the incident surface of the liquid crystal panel. And a polarizing plate having a heat conducting member formed on a surface facing the incident surface of the liquid crystal panel, and a heat radiating plate connected to the heat conducting member.

According to this structure, the polarizing plate allows only a predetermined polarization component to enter the incident surface of the liquid crystal panel. On the other hand, the reflected light from the liquid crystal panel irradiates the exit surface side of the polarizing plate, so that the temperature of the polarizing plate tends to rise. However, a heat conducting member is formed on the exit surface side of the polarizing plate, and the heat generated in the polarizing plate via this heat conducting member is transferred to the heat radiating plate and radiated. As a result, the temperature rise of the polarizing plate is suppressed and thermal deterioration is prevented.

The heat conducting member is a metal film.

According to this structure, the heat from the polarizing plate is efficiently transmitted to the heat radiating plate, and the heat radiating effect is high.

Further, the heat conducting member is formed by vapor deposition.

With such a structure, a metal film or the like can be easily formed on the polarizing plate. In addition, a sufficiently thin metal film can be formed, and light can be transmitted even when the metal film is formed on the entire surface of the polarizing plate.

Further, the heat conducting member is formed of a striped metal film.

With this structure, a liquid crystal panel having a high light transmittance and a high brightness can be obtained.

A liquid crystal device according to the present invention is built in a liquid crystal panel and an incident surface side of the liquid crystal panel, and a predetermined base material and a surface opposite to the surface of the base material facing the incident surface. A polarizing member having a stripe-shaped metal film formed and having a pitch shorter than the wavelength of the incident light, and allowing only a predetermined polarization component of the incident light to the incident surface to pass through; and heat dissipation connected to the metal film. And a plate.

According to this structure, since the pitch of the stripe-shaped metal film formed on the substrate is shorter than the wavelength of the incident light, the stripe-shaped metal film causes a polarization effect. As a result, only the predetermined polarized component of the incident light of the liquid crystal panel passes through the polarizing member. In this case, the stripe-shaped metal film has a high transmittance due to the diffracting action of light, and can enhance the brightness of the liquid crystal panel.
The heat generated in the polarizing member is radiated from the metal film via the heat dissipation plate. As a result, the temperature rise of the polarizing member is suppressed and thermal deterioration is prevented.

A projection apparatus according to the present invention is characterized by using the above liquid crystal device.

According to this structure, since the polarizing plate in which the temperature rise is suppressed and the thermal deterioration is prevented is used, the life is long.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows the first of the present invention.
FIG. 3 is an explanatory diagram showing the projection device according to the embodiment of FIG. Figure 2
FIG. 3 is an equivalent circuit diagram of various elements, wirings, etc. in a plurality of pixels that constitute a pixel area of a liquid crystal panel. FIG. 3 is a plan view of an element substrate such as a TFT substrate as viewed from the counter substrate side together with the constituent elements formed thereon, and FIG. 4 is an assembly process for bonding the element substrate and the counter substrate to enclose liquid crystal. It is sectional drawing which cuts and shows the liquid crystal panel after completion | finish in the position of the HH 'line of FIG. Further, FIG. 5 is a sectional view showing the liquid crystal panel in detail. FIG. 6 is an explanatory diagram for explaining the heat dissipation structure.

In the present embodiment, a heat conducting member is provided on the polarizing plate to radiate heat, thereby suppressing the temperature rise of the polarizing plate.

First, the structure of the liquid crystal panel will be described with reference to FIGS.

As shown in FIGS. 3 and 4, the liquid crystal panel is constructed by enclosing a liquid crystal 50 between an element substrate 10 such as a TFT substrate and a counter substrate 20. Pixel electrodes that form pixels are arranged in a matrix on the element substrate 10. FIG. 2 shows an equivalent circuit of the elements on the element substrate 10 which form the pixels.

As shown in FIG. 2, in the pixel area,
The plurality of scanning lines 3a and the plurality of data lines 6a are arranged so as to intersect with each other, and the pixel electrodes 9a are arranged in a matrix in a region partitioned by the scanning lines 3a and the data lines 6a. A TFT 30 is provided corresponding to each intersection of the scanning line 3a and the data line 6a, and the pixel electrode 9a is connected to this TFT 30.

The TFT 30 is turned on by the ON signal of the scanning line 3a, whereby the image signal supplied to the data line 6a is supplied to the pixel electrode 9a. This pixel electrode 9
A voltage between a and the counter electrode 21 provided on the counter substrate 20 is applied to the liquid crystal 50. Further, a storage capacitor 70 is provided in parallel with the pixel electrode 9a, and the storage capacitor 70 enables the voltage of the pixel electrode 9a to be retained for a time that is, for example, three digits longer than the time when the source voltage is applied. The storage capacitor 70 improves the voltage holding characteristic and enables image display with a high contrast ratio.

FIG. 5 is a schematic sectional view of a liquid crystal panel focusing on one pixel.

The groove 1 is formed in the element substrate 10 such as glass or quartz.
1 is formed. A TFT 30 having an LDD structure is formed on the groove 11 via a light shielding film 12 and a first interlayer insulating film 13.
Are formed. The groove 11 flattens the boundary surface of the TFT substrate with the liquid crystal 50.

The TFT 30 comprises a scanning line 3a forming a gate electrode via an insulating film 2 in a semiconductor layer in which a channel region 1a, a source region 1d and a drain region 1e are formed. The light shielding film 12 is formed in a region corresponding to the formation region of the TFT 30, a formation region of the data lines 6a and the scanning lines 3a described later, that is, a region corresponding to the non-display region of each pixel. The light-shielding film 12 causes the incident light to reach T
Incident on the channel region 1a, the source region 1d, and the drain region 1e of the FT 30 is prevented.

A second interlayer insulating film 14 is laminated on the TFT 30, and an intermediate conductive layer 15 is formed on the second interlayer insulating film 14. Capacitor lines 18 are arranged on the intermediate conductive layer 15 with a dielectric film 17 interposed therebetween. The capacitance line 18 is
It is composed of a capacitance layer and a light-shielding layer, constitutes a storage capacitor with the intermediate conductive layer 15, and has a light-shielding function of preventing internal reflection of light. Since the intermediate conductive layer 15 is formed at a position relatively close to the semiconductor layer, diffused reflection of light can be efficiently prevented.

A third interlayer insulating film 19 is arranged on the capacitance line 18, and a data line 6a is laminated on the third interlayer insulating film 19. The data line 6a is connected to the third and second interlayer insulating films 1
It is electrically connected to the source region 1d through the contact holes 24a and 24b penetrating through 8 and 14. A pixel electrode 9a is stacked on the data line 6a with a fourth interlayer insulating film 25 interposed therebetween. The pixel electrode 9a has a contact hole 26 penetrating the fourth to second interlayer insulating films 25, 19, and 14.
a, 26b through the capacitance line 18 to the drain region 1e
Electrically connected to. An alignment film 16 made of a polyimide-based polymer resin is laminated on the pixel electrode 9a, and is rubbed in a predetermined direction.

By supplying an ON signal to the scanning line 3a (gate electrode), the channel region 1a becomes conductive,
The source region 1d and the drain region 1e are connected to each other, and the image signal supplied to the data line 6a is applied to the pixel electrode 9a.

On the other hand, on the counter substrate 20, a counter electrode (common electrode) 21 is formed over the entire surface of the substrate 20. An alignment film 22 made of a polyimide-based polymer resin is laminated on the counter electrode 21 and rubbed in a predetermined direction.

Liquid crystal 50 is sealed between the element substrate 10 and the counter substrate 20. As a result, the TFT3
0 writes the image signal supplied from the data line 6a to the pixel electrode 9a at a predetermined timing. Depending on the written potential difference between the pixel electrode 9a and the counter electrode 21, the orientation or order of the molecular assembly of the liquid crystal 50 is changed to modulate light and enable gradation display.

As shown in FIGS. 3 and 4, the counter substrate 20.
Is provided with a light shielding film 42 as a frame that divides the display area. The light shielding film 42 is formed of, for example, the same or different light shielding material as the light shielding film 23 forming the black stripe. In the present embodiment, the light shielding film 2
3 is made of aluminum, for example, and can reflect the light incident on the light shielding film 23 with a sufficient reflectance. Thereby, the temperature rise of the liquid crystal panel can be suppressed.

A sealing material 41 for enclosing the liquid crystal in a region outside the light shielding film 42 is formed between the element substrate 10 and the counter substrate 20. The sealing material 41 is arranged so as to substantially match the contour shape of the counter substrate 20, and the element substrate 10 and the counter substrate 2 are arranged.
Stick 0 to each other. The sealing material 41 is missing in a part of one side of the element substrate 10, and a liquid crystal injection port 78 for injecting the liquid crystal 50 is formed in a gap between the element substrate 10 and the counter substrate 20 which are bonded to each other. It After the liquid crystal is injected from the liquid crystal injection port 78, the liquid crystal injection port 78 is sealed with a sealing material 79.

A data line drive circuit 61 and a mounting terminal 62 are provided along one side of the element substrate 10 in a region outside the sealing material 41 of the element substrate 10, and along two sides adjacent to the one side. , A scanning line drive circuit 63 is provided. A plurality of wirings 64 for connecting the scanning line drive circuits 63 provided on both sides of the screen display area are provided on the remaining side of the element substrate 10. The element substrate 1 is provided at least at one corner of the counter substrate 20.
A conductive material 65 is provided to electrically connect 0 and the counter substrate 20.

In the present embodiment, the projection device is constructed by using three liquid crystal panels thus formed.
In FIG. 1, a light source 110 is a metal halide lamp, a high pressure mercury lamp or the like, and reflects light from the lamp 1
It is the structure which reflects by 12 by the front. Light source 110
A fly-eye lens 115, a polarization conversion element 116, and a reflection mirror 117 are provided on the optical path of light emitted from.

The fly-eye lens 115 is composed of a first lens array 113 and a second lens array 114. The first lens array 113 splits the incident light flux and emits a large number of secondary light sources. Further, the second lens array 114 cooperates with each lens described later to make the secondary light source from the first lens array 113 overlap and enter the incident surface of the liquid crystal panel. Accordingly, the fly-eye lens 115 can irradiate the light from the light source 110 with uniform brightness on the incident surface of the liquid crystal panel.

On the exit surface side of the fly-eye lens 115,
A polarization conversion element 116 is provided. Polarization conversion element 1
Reference numeral 16 is a polarizing plate 131R, 131G, which will be described later.
It is converted into a polarization component in the transmission axis direction of 131B and emitted.
The reflection mirror 117 is provided with an inclination of about 45 degrees with respect to the optical axis and reflects the light emitted from the polarization conversion element 116. The dichroic mirror 118 and the reflection mirror 12 are provided on the optical path of the light emitted from the reflection mirror 117.
5 is arranged with an inclination of about 45 degrees with respect to the optical axis. The dichroic mirror 118 reflects blue light and green light,
Transmits red light.

The reflection mirror 125 is adapted to reflect the red light incident through the dichroic mirror 118. A field lens 126, a polarizing plate 131R for red color, a liquid crystal panel 130R, and a polarizing plate 132R are arranged on the optical path of the reflected light from the reflection mirror 125. The red light from the reflection mirror 121 is the field lens 126.
The field lens 126 collects the incident red light beam on the display surface of the liquid crystal panel 130R via the polarizing plate 131R.

On the optical path of the reflected light of the dichroic mirror 118, the dichroic mirror 119, the condenser lens 120 and the reflection mirror 12 are inclined at an angle of about 45 degrees with respect to the optical axis.
1 is provided. The dichroic mirror 119 is
Of the blue light and the green light reflected from the dichroic mirror 118, the green light is reflected and the blue light is transmitted.

On the optical path of the reflected light of the dichroic mirror 119, the field lens 127 and the green polarizing plate 13 are provided.
1G, a liquid crystal panel 130G, and a polarizing plate 132G are arranged. The green reflected light from the dichroic mirror 119 is incident on the field lens 127, and the field lens 127 focuses the incident green light flux on the display surface of the liquid crystal panel 130G via the polarizing plate 131G.

The reflection mirror 121 reflects the blue light transmitted through the dichroic mirror 119. Reflection mirror 1
On the optical path of the reflected light from the condenser lens 21, the condenser lens 12
2 and a reflection mirror 123 inclined about 45 degrees to the optical axis. The reflection mirror 123 reflects the incident blue light. A condenser lens 124, a blue polarization plate 131B, and a liquid crystal panel 130 are provided on the optical path of the reflection mirror 123.
B and a polarizing plate 132B are provided, and the reflection mirror 12
The blue reflected light from 3 enters the condenser lens 124. The condenser lens 124 focuses the incident blue light flux on the display surface of the liquid crystal panel 130B via the polarizing plate 131B.

The optical path length until the blue light reaches the condenser lens 124 is the same for the other two colors as the field lens 126,
It is longer than the optical path length until reaching 127. Therefore,
With the optical system including the condenser lens 120, the reflection mirror 121, the condenser lens 122, and the reflection mirror 123, the illumination distribution of the blue luminous flux incident on the liquid crystal panel 130B is set to the illumination distribution of the luminous flux incident on the liquid crystal panels 130R and 130G of the other two colors. It is designed to be approximately equal.

The polarizing plates 131R, 131G and 131B are
A predetermined polarization component of each incident light flux is passed and made incident on the liquid crystal panels 130R, 130G, and 130B. The liquid crystal panels 130R, 130G and 130B are respectively R, G and
The B image signal is supplied, and the incident R, G, and B lights are rotated and emitted based on the image signal. LCD panel 1
Light emitted from 30R, 130G, and 130B is emitted via polarizing plates 132R, 132G, and 132B, respectively. A cross prism 133 is arranged on the optical path of the image light emitted from the polarizing plates 132R, 132G, and 132B.

The polarizing plate 131R, the liquid crystal panel 130R, and the polarizing plate 132R cause red light to enter the cross prism 133 at a transmittance corresponding to an image signal. Similarly, the polarizing plate 131G, the liquid crystal panel 130G, and the polarizing plate 132G.
Causes the green light to enter the cross prism 133 with the transmittance according to the image signal, and the blue light to enter the cross prism 133 with the transmittance according to the image signal by the polarizing plate 131B, the liquid crystal panel 130B, and the polarizing plate 132B. It

The cross prism 133 is constructed by laminating four right-angle prisms, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a cross shape on the inner surface thereof. . The cross prism 133 combines the three R, G, and B color lights by these dielectric multilayer films and emits image light of a color image.

A projection lens 134 is arranged on the optical path of the light emitted from the cross prism 133.
Reference numeral 4 enlarges and projects the incident composite image light on the screen 135.

FIG. 6 shows polarizing plates 131R and 131 in FIG.
It is explanatory drawing for demonstrating the heat dissipation structure of G, 131B (Hereinafter, it represents typically a polarizing plate 131.).

As shown in FIG. 6, in the present embodiment, the polarizing plates 131R, 131G, 131B (131).
Has a metal film 141 as a heat conducting member formed on the emission surface side by, for example, vapor deposition. The planar shape of the metal film 141 is not particularly limited. At the end of the exit surface,
The heat sinks 136R, 136G connected to the metal film 141,
136B (136) is attached. Further, the radiator plate 136 has radiators 137R, 137G, 137B.
(137) is attached. Note that the radiator is not shown in FIG.

As a result, the heat generated by the reflected light that has entered the exit surface of the polarizing plate 131 is transferred to the radiator 137 via each heat radiating plate 136 and cooled by the radiator 137. Thus, the temperature of the exit surface of the polarizing plate 131 is prevented from rising.

As a result, the polarizing plates 131R, 131G,
It is possible to prevent the temperature of 131B from becoming higher than a predetermined temperature, and reduce deterioration of the polarizing plates 131R, 131G, 131B due to heat or the like.

The radiator 137 may be omitted and the heat dissipation plate 136 may be connected to a metal casing (not shown) of the projection device.

Next, the operation of the embodiment thus constructed will be described.

The light flux from the light source 110 passes through the fly-eye lens 115 and the polarization conversion element 116, and the reflection mirror 1
It is incident on 17. The fly-eye lens 115 irradiates the incident surface of the liquid crystal panel with light with uniform brightness. The light emitted from the fly-eye lens 115 is converted into a polarization component in the transmission axis direction of the polarizing plate 131 by the polarization conversion element 116.

The light emitted from the polarization conversion element 116 is reflected by the reflection mirror 117, and the dichroic mirrors 118, 1
The light is split into red light, green light, and blue light by 19. The red light from the dichroic mirror 118 is reflected by the reflection mirror 125, and the field lens 126
It is incident on the polarizing plate 131R via. The green reflected light from the dichroic mirror 119 is reflected by the field lens 1
It is incident on the polarizing plate 131 G via 27. The blue transmitted light from the dichroic mirror 119 receives the condenser lens 120, the reflection mirror 121, and the condenser lens 12.
2, incident on the polarizing plate 131B via the reflection mirror 123 and the condenser lens 124.

The polarizing plates 131R, 131G and 131B are
A predetermined polarization component of the incident R, G, B lights is passed and made incident on the liquid crystal panels 130R, 130G, 130B. R from the polarizing plates 131R, 131G, 131B,
The G and B lights are transmitted to the liquid crystal panels 130R, 130G and 13 respectively.
It is incident on OB. Liquid crystal panels 130R, 130G, 1
30B is R, G, which is incident by the input image signal,
B Light is rotated. Liquid crystal panels 130R, 130G, 1
The R, G and B image lights from 30B are polarized plates 132R and 13R.
It is incident on 2G and 132B and passes only a predetermined polarization axis component. Thereby, the polarizing plates 132R, 132G, 13
From 2B, R, G, and B image lights having transmittances corresponding to image signals are emitted, combined by the cross prism 133, and projected on the screen 135 in an enlarged manner.

Liquid crystal panels 130R, 130G, 130B
The light incident on the light-shielding film 23 provided on each of the counter substrates is irregularly reflected by the light-shielding film 23, and each of the polarizers 131
Irradiation is performed on the emission surface side of R, 131G, and 131B. As a result, the temperatures of the polarizing plates 131R, 131G, 131B tend to rise. However, the heat on the emission surface side of each polarizing plate 131 is transferred from each metal film 141 deposited on the emission surface to each radiator 137 via each heat dissipation plate 136, and is cooled in the radiator 137. This suppresses the temperature rise of the polarizing plates 131R, 131G, 131B and prevents each polarizing plate 131 from becoming high in heat.

As described above, in this embodiment, the metal films are provided on the emission side surfaces of the polarizing plates 131R, 131G, and 131B to increase the temperature due to the reflected light from the counter substrate.
This is suppressed by radiating heat through the heat radiating plate and the radiator, and thereby the polarizing plates 131R, 131G, 131
B is prevented from being thermally deteriorated.

In the first embodiment, the plane shape of the metal film deposited on the exit surface side of the polarizing plate is not particularly limited. However, since light does not pass through the portion where the metal film is formed, it is better to determine the shape and size of the metal film in consideration of the shape and size of the metal film, the amount of transmitted light, and the heat dissipation effect. It should be noted that when the metal film is formed to be sufficiently thin, light is transmitted even through the metal film portion. Therefore, in this case, it is also possible to deposit a metal film on the entire surface of the polarizing plate.

However, when a thin metal film is vapor-deposited on the entire emission surface side, the heat dissipation effect is high, but the transmittance of the polarizing plate is relatively low. Therefore, a method of preventing the thermal deterioration of the polarizing plate by vapor-depositing the metal film in a stripe shape to obtain a sufficient heat dissipation effect while suppressing a decrease in the transmittance can be considered.

FIG. 7 relates to a second embodiment of the present invention,
It is explanatory drawing which shows the liquid crystal device which employ | adopted the polarizing plate in which such a striped metal film was formed.

In FIG. 7, a liquid crystal panel 151 is the same liquid crystal panel as in the first embodiment, and the element substrate 1
52 and the counter substrate 153 are bonded together. A polarizing plate 155 is arranged on the counter substrate 153 side (incident surface side), and a polarizing plate 154 is arranged on the TFT substrate 152 side (emission surface side).

In this embodiment, a striped metal film 156 is formed on the exit surface side (opposite substrate 153 side) of the polarizing plate 155 by, for example, vapor deposition. A heat dissipation plate 136 connected to the metal film 156 is attached to the end of the polarizing plate 155 on the emission surface side.

In the embodiment configured as described above, the light from the lamp 150 passes through the polarizing plate 155 and enters the liquid crystal panel 151. In this case, the polarizing plate 15
The heat-dissipating metal film 156 formed in No. 5 is formed in a stripe shape, and the light transmittance of the polarizing plate 155 is relatively high.

Light is emitted to the emission surface side of the polarizing plate 155 by irregular reflection by the black stripes of the counter substrate 153. The heat generated in the polarizing plate 155 by this irradiation light is
Striped metal film 156 formed on the polarizing plate 155
Is transmitted to the heat radiating plate 136 via, and further radiated through a radiator (not shown).

As described above, in the present embodiment, as in the embodiment of FIG. 1, the polarizing plate has a sufficient heat dissipation effect and suppresses the deterioration of the light transmittance to increase the brightness. It is possible to promote.

FIG. 8 is an explanatory view showing a polarizer using a structural birefringent body adopted in the liquid crystal device according to the third embodiment of the present invention.

In this embodiment, the polarizing plate is constituted by a polarizer having a structural birefringent body. In the second embodiment, a stripe-shaped metal film is formed on the exit surface side of the polarizing plate. When the pitch of the striped metal film is smaller than the wavelength of light, the striped metal film also acts as a polarizer. As described above, the structural birefringent body has both a polarization effect and a liquid crystal alignment effect.

By utilizing this characteristic, the present embodiment is such that the structural birefringent body is incorporated in the liquid crystal device. The structural birefringent body is a structure body having an effective refractive index that differs depending on the polarization direction of incident light. Utilizing the fact that the effective refractive index differs depending on the polarization direction of light incident on the structural birefringent body, it is possible to transmit only specific polarized light and reflect only specific polarized light.

First, the structure of the structural birefringent body will be described with reference to FIG.

As the structural birefringent body, a structural birefringent body having a plurality of light reflectors arranged in stripes at a pitch smaller than the wavelength of light incident on the liquid crystal layer is adopted. With such a structure, as described above, the structural birefringent body can transmit only specific polarized light and reflect only specific polarized light.

As shown in FIG. 8, in the structural birefringent body 100 having a structure including a plurality of mediums A101 arranged in a stripe pattern at a pitch smaller than the wavelength of incident light, the space between adjacent media A101 is Needs to be filled with a medium B102 having a refractive index different from that of the medium A101. The medium B102 is a solid,
It does not matter whether it is liquid or gas.

In the structural birefringent body 100 having such a structure, since the refractive index n1 of the medium A101 and the refractive index n2 of the medium B102 are different, the effective refractive index depends on the polarization direction of the light incident on the structural birefringent body 100. Is different. For example, when the refractive index n1 of the medium A101 is larger than the refractive index n2 of the medium B102, the effective refractive index of the polarized light A vibrating in a direction substantially parallel to the extending direction of each medium A101 is the respective medium A101. Is larger than the effective refractive index of the polarized light B that oscillates in a direction substantially perpendicular to the extending direction of the.

When the medium A and the medium B are made of a dielectric material, the thickness of the medium A101 is a and the thickness of the medium B102 is b.
Then, of the light incident on the structural birefringent body 100, the effective refractive index Na for the polarized light A and the effective refractive index Nb for the polarized light B may be represented by the following formulas (1) and (2), respectively. Known (eg M. Born and E. Wol
f: Princjples of optics, lst ed. (rergamon Pres
s, New York, 1959) p.705-708)). As can be seen from the following equations (1) and (2), the effective refractive index can be changed in the range of n1 to n2 by the ratio of the thickness a of the medium A101 and the thickness b of the medium B102.

[0084] Thus, the structural birefringent body shows different optical properties depending on the polarization state of light. Here, when a light reflector such as a metal or a semiconductor is used as the medium A, by treating the permittivity as a complex number, it is possible to treat it in the same manner as when obtaining the effective refractive index with respect to the dielectric. However, the effective refractive index is a complex number. Effective Medium Theor
y) (eg Dominique Lemercler−lalanne: Journal
From Modernoptics, 1996, vol43, no.10, 2063-2085), strictly speaking, Rigorous Coupled-Wave Analysis (MG
Numerical calculation using Moharam: J.Opt.soc.Am.A, 12 (1995) 1077) shows that when a metal is used as the medium A, the imaginary part of the effective refractive index of the structural birefringent body with respect to the polarization A is Is large, and as a result, the incident polarized light A is known to be reflected by the structural birefringent body. On the other hand, polarization B
The imaginary part of the effective refractive index with respect to
Is known to pass through a structural birefringent body.

As described above, by forming a periodic structure smaller than the wavelength with two kinds of media, the same action as that of the light reflection type polarizer, that is, the polarization parallel to the optical axis (transmission axis) of the structural birefringent body is obtained. It is possible to have a function of transmitting light with respect to, and reflecting with respect to vertically polarized light.

In the present embodiment, the structural birefringent body is made of a light-reflecting conductive material such as aluminum, silver or a silver alloy. And
At the end of the striped metal film forming the structural birefringent body, a radiator plate similar to that of the first and second embodiments is connected (not shown).

In the embodiment configured as described above, the structural birefringent body is incorporated on the incident surface side of the liquid crystal device so that only the incident light having a predetermined polarization axis is used without using a polarizing plate. Can be made incident on the incident surface.

The light reflected by the black stripe of the counter substrate is applied to the polarizer side of the structural birefringent body. However, in the present embodiment, the heat generated by the structural birefringent is radiated through the heat dissipation plate connected to the striped metal film forming the structural birefringent, so that the temperature of the structural birefringent is reduced. The rise is suppressed, the high temperature of the entire liquid crystal device is prevented, and thermal deterioration does not occur.

Further, since the striped metal film has a polarization effect, a glass plate can be used as a substrate on which the striped metal film is deposited. Therefore, the light transmittance can be improved as compared with the case where the iodine-based polarizing plate is used. Further, the striped metal film improves the light transmittance due to the diffraction effect of light. As a result, in this embodiment, it is possible to significantly increase the amount of incident light.

[0090]

As described above, according to the present invention, it is possible to prevent the polarizing plate from being thermally deteriorated by the reflected light from the liquid crystal panel.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a projection device according to a first embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram of various elements, wirings, and the like in a plurality of pixels forming a pixel area of a liquid crystal panel.

FIG. 3 is a plan view of an element substrate, such as a TFT substrate, as viewed from the counter substrate side together with the respective constituent elements formed thereon,

FIG. 4 shows a liquid crystal panel after completion of an assembly process in which an element substrate and a counter substrate are bonded to each other and liquid crystal is sealed, taken along line HH ′ of FIG.
Sectional drawing which cuts and shows in the position of a line.

FIG. 5 is a cross-sectional view showing a liquid crystal panel in detail.

FIG. 6 shows polarizing plates 131R, 131G, 131B in FIG.
Explanatory drawing for demonstrating the heat dissipation structure of FIG.

FIG. 7 is an explanatory diagram showing a liquid crystal device that employs a polarizing plate on which a striped metal film is formed according to the second embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a polarizer using a structural birefringent body adopted in a liquid crystal device according to a third embodiment of the invention.

[Explanation of symbols]

131R, 131G, 131B ... Polarizing plate 130R, 130G, 130B ... Liquid crystal panel 132R, 132G, 132B ... Polarizing plate 136R, 136G, 136B ... Heat sink

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03B 21/00 G03B 21/00 E 2K103 21/16 21/16 5C058 H04N 5/74 H04N 5/74 K F Terms (reference) 2H049 BA02 BA42 BA45 BB03 BB11 BC22 2H052 BA02 BA03 BA09 BA14 2H088 EA14 EA15 GA02 HA08 HA13 HA14 HA18 HA25 HA28 JA05 MA20 2H091 FA05X FA07X FA07Z FA29 A01 A05 2A09 A01 A05 2 AA11 AB04 BC16 DA03 DA11 5C058 AA09 AB01 AB05 BA05 BA30 EA26

Claims (6)

[Claims] 1. A surface which is provided so as to face an incident surface of a liquid crystal panel and emits only a predetermined polarization component of incident light to the incident surface of the liquid crystal panel, the surface facing the incident surface of the liquid crystal panel. A liquid crystal device comprising: a polarizing plate having a heat conducting member formed in 1. and a heat dissipation plate connected to the heat conducting member. 2. The liquid crystal device according to claim 1, wherein the heat conducting member is a metal film. 3. The liquid crystal device according to claim 1, wherein the heat conducting member is formed by vapor deposition. 4. The liquid crystal device according to claim 1, wherein the heat conducting member is formed of a stripe-shaped metal film. 5. A liquid crystal panel and a built-in liquid crystal panel on an incident surface side of the liquid crystal panel. And a heat dissipation plate connected to the metal film. And liquid crystal device. 6. A projection apparatus comprising the liquid crystal device according to claim 1. Description: