JPH0580313A - Liquid crystal display device for liquid crystal projector - Google Patents

Abstract

PURPOSE:To reduce variation in the optical characteristics of a liquid crystal element due to the heat of light from a light source by increasing the cooling efficiency of the liquid crystal element by cooling air blown in the projector main body and to facilitate optical axis alignment with the optical system of the projector main body. CONSTITUTION:This liquid crystal element 11 is provided in a housing which has openings 33 and 34 in its front and rear surfaces opposite the liquid crystal element and an incidence-side polarizing plate 12 and a projection-side polarizing plate 13 are fitted to a couple of polarizing plate support frames 60a and 60b, supported at plural positions, in front and behind the housing 30 at intervals; and the housing 30 is supported on a fixed plate 20, fixed in the projector main body perpendicularly to the optical axis of the optical system, slidably in all directions along the surface of this fixed plate.

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 for a liquid crystal projector.

[0002]

2. Description of the Related Art A liquid crystal projector projects a display image of a liquid crystal display device onto a projection surface such as a screen by a projection lens. This liquid crystal projector uses one liquid crystal display device to emit the liquid crystal display device. Three liquid crystal display devices, one for projecting black and white image light or color image light, one for displaying a red image, one for displaying a green image and one for displaying a blue image are used. There is a method in which the image light of is combined into one color image light and the combined image light is projected. FIG. 6 is a plan view showing the principle configuration of a liquid crystal projector using three liquid crystal display devices.

This liquid crystal projector is for separating three liquid crystal display devices LCD1, LCD2, LCD3, a light source 2 and light R, G, B of three primary colors of red, green and blue. Two dichroic mirrors D for color separation
M1, DM2 and the above three liquid crystal display devices LCD1, L
It is composed of two color-combining dichroic mirrors DM11 and DM12 forming an optical system for combining the image light emitted from the CD2 and the LCD3 into one image light, and the projection lens 3. It is provided on the front surface of the projector body 1, and the other components are arranged in the projector body 1 as shown in the figure.

The above three liquid crystal display devices LCD1 and LCD
2. Among the LCDs 3, LCD 1 is a red image display device for displaying a red component image, LCD 2 is a green image display device for displaying a green component image, and LCD 3 is a blue image display device for displaying a blue component image. It is an image display device.

These display devices LCD1, LCD2, LC
D3 is a TN type or STN type liquid crystal element 11 respectively.
And an incident side polarization plate 12 and an emission side polarization plate 13 arranged in front of and behind the liquid crystal element 11 (on the light incident surface side and the light exit surface side).

Each of the display devices LCD1, LCD2, LC
The liquid crystal elements 11 of D3 are all matrix display elements having the same number of pixels, and the liquid crystal element 11 of the red image display device LCD1 is displayed according to the image data of the red component among the image data of the red, green and blue color components. The liquid crystal element 11 of the green image display device LCD2 is driven to display according to the image data of the green component, and the liquid crystal element 1 of the blue image display device LCD3 is driven.
1 is driven for display according to the image data of the blue component.

The light source 2 is composed of a high-intensity light source lamp 2a for emitting white light and a reflector 2b. The light from the light source 2 is reflected by a mirror M1 to form a first color separation dichroic mirror. It is incident on DM1. In addition,
The reflector 2b is a parabolic reflector that reflects the light emitted from the light source lamp 2a in a direction parallel to the reflector optical axis.

The first color separation dichroic mirror DM1 has a characteristic of reflecting, for example, light in the blue wavelength band of light in the visible light band and transmitting light in other wavelength bands. The white light from is first separated into light in the blue wavelength band and light in other wavelength bands by the first color separation dichroic mirror DM1, and the blue light B separated by the dichroic mirror DM1 is a mirror. It is reflected by M2 and enters the blue image display device LCD3.

The second color separation dichroic mirror DM2 receives the light (the light including the light in the red wavelength band and the light in the green wavelength band) transmitted through the first color separation dichroic mirror DM1. Among them, it has the property of reflecting light in the green wavelength band and transmitting light in the red wavelength band,
Green light G separated by this dichroic mirror DM2
Enters the green image display device LCD2, and the red light B enters the red image display device LCD1.

The red light R incident on the red image display device LCD1 is transmitted through the red image display device LCD1 to become red image light Ra, and the green light G incident on the green image display device LCD2 is converted to the green image. The green image light Ga is transmitted through the display device LCD2, and the green light B incident on the blue image display device LCD3 is transmitted through the blue image display device LCD3 to be blue image light Ba.

Further, the blue image light Ba emitted from the blue image display device LCD3 and the green image light Ga emitted from the green image display device LCD2 enter the first color combining dichroic mirror DM11 to display a red image. The red image light Ra emitted from the device LCD1 is reflected by the mirror M3 and enters the second color combining dichroic mirror DM12.

In this liquid crystal projector, a luminous flux reduction lens 14 is arranged on the emission side of each of the display devices LCD1, LCD2, LCD3, and each of the display devices LCD.
1, LCD2, LCD3 emitted image light Ra, Ga,
Ba is incident on the color combining dichroic mirrors DM11 and DM12 through the light flux reducing lens 14. If the light flux reduction lens 14 is provided, the image light Ra, G of each color is obtained.
Since a and Ba can be made to enter the projection lens 3 by reducing the light flux thereof, the projection lens 3 can be configured by a relatively inexpensive lens having a small diameter.

The first color combining dichroic mirror DM11 has a characteristic of transmitting light in the blue wavelength band and reflecting light in other wavelength bands, and the blue image light Ba transmits through the dichroic mirror DM11. And green image light Ga
Is reflected by the dichroic mirror DM11, so that both image lights Ga and Ba are combined into an image light of a combined color (cyan) of green and blue.

The image light combined by the first color combining dichroic mirror DM11 is incident on the second color combining dichroic mirror DM12 and is combined with the red image light Ra incident on the dichroic mirror DM12. It

The second color combining dichroic mirror DM12 reflects light in the green and blue wavelength bands,
It has a characteristic of transmitting light in other wavelength bands, image light of a composite color of green and blue is reflected by the dichroic mirror DM12, and red image light Ra is dichroic mirror DM12.
To transmit red, green,
The color image light is a combination of the three primary colors of blue.

Then, the color image light is incident on the projection lens 3, the luminous flux is enlarged at an enlargement ratio according to the magnification of the projection lens 3, and projected on a projection surface such as a screen (not shown).

Although a liquid crystal projector using three liquid crystal display devices has been described here, a liquid crystal projector using one liquid crystal display device is configured by disposing the liquid crystal display device between a light source and a projection lens. There is.

By the way, a liquid crystal display device used in the above liquid crystal projector is conventionally a fixing plate fixed in the projector main body perpendicularly to the optical axis of its optical system (optical system between the light source and the projection lens). A movable plate is attached to the movable plate, the liquid crystal element is fixed to one surface of the movable plate, the incident side polarization plate is adhered to the incident surface of the liquid crystal element, and the emission side polarization plate is attached to the other surface of the movable plate. ing.

The alignment of the optical axis of the liquid crystal display device with the optical system is performed by moving the movable plate along the fixed plate surface and adjusting the mounting position thereof. When moved along, the liquid crystal element and the incident-side polarizing plate and the emitting-side polarizing plate move integrally while maintaining a fixed positional relationship. The optical axis can be easily adjusted only by adjusting the position of the movable plate without individually adjusting the position of the side polarizing plate.

[0020]

However, although the above-mentioned conventional liquid crystal display device can easily align the optical axis with the optical system of the projector main body, on the other hand, it has a problem that the cooling property of the liquid crystal element is poor.

That is, a high-intensity lamp such as a xenon lamp is used as the light source of the liquid crystal projector. Since the emitted light from this high-intensity lamp has high heat, the light incident on the liquid crystal display device from the light source is high. The temperature of the liquid crystal element rises due to heat, and its optical characteristics change. Therefore, in the liquid crystal projector, the liquid crystal element is air-cooled by ventilating the inside of the projector body with a blower fan or the like. In this case, since the temperature of the liquid crystal element rises to a greater extent on the side on which heat-laden light is incident, it is important to efficiently cool the incident surface side of the liquid crystal cell.

However, in the above conventional liquid crystal display device, since the incident side polarizing plate is adhered to the incident surface of the liquid crystal element,
The incident surface side of the liquid crystal element is cooled from the outside of the incident side polarizing plate, and therefore the incident surface side of the liquid crystal element cannot be cooled efficiently, so that the temperature of the liquid crystal element is greatly increased and the optical characteristics are deteriorated. It changes and it becomes impossible to display a normal image on the liquid crystal display device.

An object of the present invention is to enhance the cooling efficiency of the liquid crystal element by the cooling air ventilated in the projector body and reduce the change in the optical characteristics of the liquid crystal element due to the heat of the light from the light source. An object of the present invention is to provide a liquid crystal display device for a liquid crystal projector that can easily perform optical axis alignment with the optical system of the projector body.

[0024]

A liquid crystal display device for a liquid crystal projector according to the present invention comprises a liquid crystal element and incident side and emission side polarizing plates arranged in front of and behind the liquid crystal element. Is provided in a housing having an opening corresponding to the liquid crystal element, and the incident-side polarization plate and the emission-side polarization plate are arranged in front of and behind the housing and spaced apart from the housing, and are supported by the housing at a plurality of positions. The housing is attached to a pair of polarizing plate supporting frames, respectively, and the housing is fixed to a fixing plate fixed in the projector main body perpendicularly to the optical axis of the optical system.
It is characterized in that it is slidably supported in all directions along the surface of the fixed plate.

[0025]

That is, in the liquid crystal display device for a liquid crystal projector of the present invention, the liquid crystal element is provided in the housing having the openings corresponding to the liquid crystal element on the front and rear surfaces, and the incident side polarizing plate and the emitting side polarizing plate are arranged on the front and rear sides of the housing. By disposing the housing separately from the housing, a ventilation gap of cooling air that is ventilated in the projector body is secured between the liquid crystal element and both of the polarizing plates. According to this liquid crystal display device, The liquid crystal element is efficiently cooled from the incident surface side by the cooling air passing between the incident surface and the incident side polarizing plate, and from the emitting surface side by the cooling air passing between the emitting surface and the emitting side polarizing plate. Is also efficiently cooled, so that the cooling efficiency of the liquid crystal element by the cooling air is increased to suppress the temperature rise of the liquid crystal element due to the heat of the light from the light source, and the change in the optical characteristics of the liquid crystal element. It can be reduced.

In addition, in this liquid crystal display device, a pair of front and rear polarizing plate supporting frames are supported by a housing having a liquid crystal element inside, and the polarizing plate supporting frame is provided with an incident side polarizing plate and an outgoing side polarizing plate, respectively. Since it is attached, by moving the housing along the surface of the fixed plate, it is possible to integrally move the liquid crystal element and the incident side polarization plate and the emission side polarization plate while maintaining a constant positional relationship, Therefore, even though a ventilation gap is secured between the liquid crystal element and both of the polarizing plates, the light to the optical system of the projector main body is not adjusted without individually adjusting the positions of the liquid crystal element and the incident side and emission side polarizing plates. The axis can be easily aligned.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 is a side view of the liquid crystal display device, FIG. 2 is a plan view, FIG. 3 is a front view seen from the incident surface side, and FIG. 4 is a rear view.
FIG. 5 is an exploded perspective view.

In FIGS. 1 to 5, reference numeral 20 denotes a fixed plate which is fixed in the main body of the projector perpendicularly to the optical axis of its optical system. The fixing plate 20 is made of one metal plate, and at its lower end and upper part, chassis fixing pieces 20a, 20 are screwed to the bottom plate 4a and the top plate 4b of the chassis provided in the projector main body, respectively.
b is bent and a large-area opening 21 is formed in the center.

A housing 30 for housing the liquid crystal element 11 is provided on one surface of the fixed plate 20.
It is slidably supported in all directions along the surface.
The housing 30 is composed of a housing front plate 31 and a rear plate 32 having openings 33 and 34 corresponding to the liquid crystal element 11 formed in the center thereof. The front plate 31 and the rear plate 3 are formed.
2 means that the lower edge portions thereof are fitted by fitting the pin 35 and the pin fitting hole 36 and the upper edge portions thereof are screwed 37.
Are fastened and combined by.

The housing 30 is arranged with its front plate 31 facing the fixed plate 20, and can be slid in all directions on the fixed plate 20 at a plurality of positions (three in this embodiment) of the front plate 31. Supported by.

The supporting structure of the housing front plate 31 with respect to the fixed plate 20 will be described. Referring to FIG.
Reference numeral 8 is a support screw for supporting the housing front plate 31 on the fixed plate 20, 22 is a square hole-shaped screw through hole provided in the fixed plate 20, 39 is each of the screw through holes 22.
Screw holes provided on the housing front plate 31 in correspondence with the
Is formed in an area sufficiently larger than the thickness of the supporting screw 38. Further, 40 and 41 are a pair of sliding washers for sandwiching the screw through hole forming portion of the fixed plate 20 from both sides thereof, and the sliding washers 40 and 41 are made of low friction resin.

The support screw 38 is provided with one sliding washer 40 and the screw through hole 22 of the fixed plate 20.
And the other slide washer 41 are screwed into the screw holes 39 of the housing front plate 31, and the housing front plate 31 applies the tightening force of the support screw 38 to the pair of slide washers 40 and 41 and the fixed plate 20. Tolerate sliding
Further, the housing front plate 31 is slidably supported by the fixed plate 20 in all directions by adjusting the housing front plate 31 through the slide washer 41 so that the fixed plate 20 is brought into contact with the fixed plate 20 with contact pressure so as not to cause "backlash". Has been done.

In FIG. 5, reference numeral 42 designates two fixing screws for fixing the housing front plate 31 to the fixing plate 20. The fixing screws 42 are the fixing screws 20.
Through screw holes 23 provided on both sides of the upper end of the housing front face plate 31 and screw holes 43 provided on both sides of the upper end of the housing front plate 31. The fixing screw 42 is used for the housing 30.
Is slid along the surface of the fixed plate 20 to perform optical axis alignment described later, and then tightened. The screw through hole 23 is formed to have a diameter sufficiently larger than that of the fixing screw 42 so that the screw of the housing 30 does not interfere with the sliding of the housing 30, and the head of the fixing screw 42 is fixed via a large diameter washer 44. It is in contact with the plate 20.

The liquid crystal element 11 accommodated in the housing 30 is a TN type or STN type matrix liquid crystal element, and the liquid crystal element 11 includes a scanning side drive circuit D1.
And the signal side drive circuit D2 is connected.

The liquid crystal element 11 and its drive circuits D1 and D2 are arranged on the front and rear surfaces of the screen area 11a of the liquid crystal element 11.
The liquid crystal device module 50 is housed in a thin case 51 having an opening 52 corresponding to the housing 52. The liquid crystal device module 50 is housed in the housing 30 in the state of the liquid crystal device module 50. It is fixed to.

On the other hand, a plurality of polarizing plate support posts 4 (three in the figure) are provided on the front and rear surfaces of the housing 30, that is, on the outer surfaces of the housing front plate 31 and the rear plate 32, respectively.
5, 46 are provided so as to project, and the rear plate 3 of the housing is further provided.
On the outer surface of 2, a plurality of (three in the figure) lens support posts 47 are provided so as to be displaced from the polarizing plate support posts 46.

The polarizing plate support post 45 on the front surface of the housing 30 projects to the opposite surface side of the fixed plate 20 through the escape hole 24 formed in the fixed plate 20 in the shape of a square hole. The escape hole 24 is formed in an area sufficiently larger than the polarizing plate support post 45 so as not to hinder the sliding of the housing 30.

A polarizing plate support frame 60a for supporting the incident side polarizing plate 12 is attached to the tip of the polarizing plate support post 45 in a state of being separated from the housing 30 and the fixed plate 20. This polarizing plate support frame 60a has its back surface supported by the front end face of the polarizing plate support post 45, and is screwed to the polarizing plate support post 45 through a long hole 61 provided in the polarizing plate support frame 60a. It is fastened and fixed to the polarizing plate support post 45.

The incident side polarizing plate 12 is attached to the polarizing plate supporting frame 60a by a polarizing plate pressing plate 63 and its fastening screws 64.
The direction of the second polarization axis (transmission axis or absorption axis) is adjusted by loosening the screw 62 fixing the polarizing plate support frame 60a to the polarizing plate support post 45 and rotating the polarizing plate support frame 60a in the circumferential direction. By doing so, it is aligned in a predetermined direction.

On the other hand, a polarizing plate support frame 60b for supporting the outgoing side polarizing plate 13 is attached to the tip of the polarizing plate support post 46 on the rear surface of the housing 30 while being separated from the housing 30. The polarizing plate support frame 60b is the same as the polarizing plate support frame 60a that supports the incident side polarizing plate 12, and the back surface of the polarizing plate support frame 60b is also supported by the front end face of the polarizing plate support post 46. The long hole 61 is fastened and fixed to the polarizing plate support post 46 with a screw 62.

The emission side polarization plate 13 is attached to the polarization plate support frame 60b by a polarization plate pressing plate 63 and its fastening screws 64.
The direction of the polarization axis is also adjusted to a predetermined direction by rotationally adjusting the polarizing plate support frame 60a in the circumferential direction.

Further, the tip end of the lens support post 47 projectingly provided on the rear surface of the housing 30 has the above-mentioned polarizing plate support frame 60.
The lens support post 47 is loosely fitted in the post through hole (long hole) 63 provided in b, and the light flux reduction lens 14 for reducing the light flux of the light emitted from the liquid crystal display device is held at the tip of the lens support post 47. A lens frame 70 is attached.

That is, in the above liquid crystal display device, the liquid crystal element module 50 in which the liquid crystal element 11 and its driving circuits D1 and D2 are housed in the thin case 51 having the opening 52 corresponding to the screen area 11a of the liquid crystal element 11 is arranged in the front and rear. The incident side polarization plate 12 and the emission side polarization plate 13 are provided in a housing 30 having openings 33 and 34 corresponding to the liquid crystal element 11 on its surface.
Is a post 45 protruding from the front and rear of the housing 30,
46 is attached to the pair of front and rear polarizing plate support frames 60a and 60b provided in a state of being separated from the housing 30 by being supported by 46, and the housing 30 is fixed in the projector main body perpendicularly to the optical axis of its optical system. The fixed plate 20 is slidably supported in all directions along the fixed plate surface.

This liquid crystal display device is installed in the projector body by fixing the fixing plate 20 to the bottom plate 4a and the top plate 4b of the chassis provided in the projector body. The optical axis alignment of the liquid crystal display device with respect to the optical system between the lens)
The fixing screw 42 that fixes the housing 30 to the fixing plate 20 is loosened, and the housing 30 is slid along the surface of the fixing plate.
And the incident-side and exit-side polarizing plates 12 and 1 supported by the housing 30 via the polarizing plate supporting frames 60a and 60b.
It is performed by moving 3 and 3.

In this embodiment, since the light flux reducing lens 14 for reducing the light flux of the light emitted from the liquid crystal display device is supported by the housing 30, the light flux reducing lens 14 is also moved by sliding the housing 30. The liquid crystal element 11 and the polarizing plates 12 and 13 are moved while maintaining a fixed positional relationship.

In the above liquid crystal display device, the liquid crystal element 11 is provided with the openings 3 corresponding to the liquid crystal element 11 on the front and rear surfaces.
The liquid crystal element 11 and both of the polarizing plates 12 are provided in the housing 30 having 3, 34, and the incident side polarizing plate 12 and the emitting side polarizing plate 13 are provided in front of and behind the housing 30 and spaced from the housing 30. , 13 can pass cooling air ventilated into the projector main body.

Therefore, according to this liquid crystal display device,
The liquid crystal element 11 is efficiently cooled from the incident surface side by the cooling air passing between the incident surface and the incident side polarizing plate 12, and is emitted by the cooling air passing between the emitting surface and the emitting side polarizing plate 13. Because it is cooled efficiently from the surface side,
The efficiency of cooling the liquid crystal element 11 by the cooling air is increased to suppress the temperature rise of the liquid crystal element 11 due to the heat of the light from the light source, and the change in the optical characteristics of the liquid crystal element 11 is reduced, so that an image of good quality is always displayed can do.

In the above embodiment, the liquid crystal element 11 and its drive circuits D1 and D2 are housed in the thin case 51 to form a module, and the liquid crystal element module 50 is housed in the housing 30. Element module 5
Since the opening 51 corresponding to the screen area 11a of the liquid crystal element 11 is provided on the front and rear surfaces of the case 51 of 0, the cooling air is discharged through the openings 33, 3 on the front and rear surfaces of the housing 30.
4, and the liquid crystal element 11 is directly cooled in the openings 52 on the front and rear surfaces of the liquid crystal element module 50.

In addition, in the above liquid crystal display device, a pair of front and rear polarizing plate supporting frames 60a and 60b are supported by the housing 30 in which the liquid crystal element 11 is provided, and the polarizing plate supporting frames 60a and 60b are provided on the incident side polarizing plate. 12 and the exit side polarization plate 13 are attached to each other, the housing 3
By moving 0 along the fixed plate surface,
Liquid crystal element 11, incident side polarization plate 12 and emission side polarization plate 1
3 can be moved integrally while maintaining a fixed positional relationship, and therefore, a ventilation gap through which cooling air passes is secured between the liquid crystal element 11 and both of the polarizing plates 12 and 13. The optical axis can be easily adjusted with respect to the optical system of the projector body without individually adjusting the positions of the liquid crystal element 11 and the incident side and emission side polarizing plates 12 and 13.

In the above embodiment, the liquid crystal element 11 and its drive circuits D1 and D2 are housed in the thin case 51 to form a module, and the liquid crystal element module 50 is housed in the housing 30. The element 11 and the drive circuits D1 and D2 are directly connected to the housing 3 without being modularized.
It may be provided within 0.

Further, the liquid crystal display device of the present invention can be used for a liquid crystal projector using the three liquid crystal display devices shown in FIG. 6 and also for a liquid crystal projector using one liquid crystal display device.

[0052]

In the liquid crystal display device for a liquid crystal projector of the present invention, a liquid crystal element is provided in a housing having openings on the front and rear surfaces corresponding to the liquid crystal element, and the incident side polarization plate and the emission side polarization plate are the same as those of the housing. The housing is attached to a pair of front and rear polarizing plate support frames that are spaced apart from the housing in the front and back and supported by the housing at a plurality of locations, and the housing is fixed in the projector body perpendicularly to the optical axis of its optical system. Since the fixed plate is slidably supported in all directions along the surface of the fixed plate, the efficiency of cooling the liquid crystal element by the cooling air ventilated in the projector main body is increased and the light from the light source is increased. It is possible to reduce the change in the optical characteristics of the liquid crystal element due to the heat of the projector, and moreover, to align the optical axis with the optical system of the projector body It can be carried out in.

[Brief description of drawings]

FIG. 1 is a side view of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a plan view of the liquid crystal display device.

FIG. 3 is a front view of the liquid crystal display device seen from the incident surface side.

FIG. 4 is a rear view of the liquid crystal display device.

FIG. 5 is an exploded perspective view of the liquid crystal display device.

FIG. 6 is a plan view showing the principle configuration of a liquid crystal projector using three liquid crystal display devices.

[Explanation of symbols]

11 ... Liquid crystal element, 12 ... Incident side polarization plate, 13 ... Emission side polarization plate, 20 ... Fixed plate, 30 ... Housing, 33,
34 ... Aperture, 50 ... Liquid crystal element module, 60a, 60
b ... Polarizing plate support frame.

Claims (1)

[Claims] 1. A liquid crystal display device used in a liquid crystal projector, comprising a liquid crystal element and incident side and emission side polarizing plates arranged in front of and behind the liquid crystal element, the front and rear surfaces of the liquid crystal element corresponding to the liquid crystal element. A pair of front and rear polarizing plate support frames provided in a housing having an opening, the incident side polarizing plate and the emitting side polarizing plate being spaced apart from the housing before and after the housing and supported by the housing at a plurality of positions. And the housing is supported by a fixed plate fixed in the projector main body perpendicularly to the optical axis of the optical system so as to be slidable in all directions along the fixed plate surface. Liquid crystal display device for liquid crystal projector.