JPH10239775A - Projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the breakdown of a lamp and the breakage and characteristic deterioration of a member in a case, by arranging a temperature fuse in the vicinity of a light source lamp and cutting off a power source when the inside of the case is overheated by the light source, lamp. SOLUTION: A lamp housing unit 15 supports a projection light source lamp 26 in box-shaped frames 25A and 25B. The unit 15 is supported by an outer housing 23. The housing 23 is provided with a light guiding barrel 36 continued to the light guiding barrel 30 of the unit 15. A part of outside air entering from a slit 37 formed on a panel part 32 flows around the lamp 26 by the guiding action of an air guiding barrel 31, so that the unit 15 is cooled. The temperature fuse is arranged in the vicinity of the lamp 26, and cuts off the power source when the inside of the projector case is overheated by the lamp 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projector which uses a light valve for image formation and performs enlarged projection by a lens to display a large screen.

[0002]

2. Description of the Related Art A so-called liquid crystal projector that combines three light components using three liquid crystal light valves for controlling red, green, and blue light, and enlarges and projects the combined light through a lens. Known (for example, see Japanese Patent Application No. 60-
179723, JP-A-61-150487).

[0003]

In the above-described conventional liquid crystal projector, the size and weight of the device are reduced by performing mixed color synthesis of red, green, and blue light using a plurality of dichroic mirrors. Although it is much smaller than a video project using a CRT, it is not sufficiently miniaturized. In order to obtain a compact and compact liquid crystal projector, the present applicant first performs color mixing and synthesis using one dichroic mirror prism instead of using a plurality of dichroic mirrors, and adjusts the optical path length of the projection light source and each liquid crystal light valve. It is proposed that the color light with the high intensity be set to be the longest and the color light with the low intensity be set to be the shortest, and that only one of the three liquid crystal light valves be controlled so as to perform left-right inverted display. .

According to the present invention, operability and operability are improved by modifying the arrangement of related members around the above based on the above configuration.
The goal is to provide a project with excellent durability and maintainability.

[0005]

In order to achieve the above object, a liquid crystal projector according to the present invention is a projector for projecting light modulated based on light from a light source lamp, wherein a temperature fuse is provided near the light source lamp. The power supply is shut off when the inside of the projector case is overheated by the light source lamp.

Further, a cooling fan for the light source lamp is disposed near the light source lamp.

[0007]

In the embodiment of the present invention, the following configuration will be described.

A base plate is provided in a rectangular parallelepiped case, and a lamp housing unit having a projection light source, a light guide unit having a built-in light separating means, a liquid crystal light valve for image formation, a photosynthetic prism, and a projection lens are provided on the base plate. And an optical head unit in which the main optical path is L-shaped in a plan view.
The projection lens faces the window on the front of the case, and the lamp housing unit faces the opening on the back of the case.

A power supply unit is arranged between one side of the case and the lamp housing unit, and a drive control circuit unit is arranged between the other side of the case and the light guide unit. And a lamp housing unit cooling fan in a space surrounded by the light guide unit, the lamp housing unit, and the front surface and one side surface of the case caused by the formation of the L-shaped main optical path. Provide.

The lamp housing unit, the light guide unit, the optical head unit, the power supply unit, and the drive control circuit unit are provided separately and detachably from the base plate.

The drive control circuit unit is separated into an analog circuit unit and a digital circuit unit, and one of the circuit units is arranged on the upper surface of the light guide unit.

The lamp housing unit is characterized in that it is positioned and supported in an outer housing fixed to a base plate so that the lamp housing unit can be taken in and out through an opening on the back of the case.

Light emitted from the projection light source (white light) and guided to the light guide unit is separated into three primary colors of red, green and blue in the unit, and each color light is transmitted through the respective liquid crystal light valve. Are modulated by a video signal for each color input to each liquid crystal light valve.

Each of the modulated color lights is mixed and synthesized by the prism, and is simultaneously guided to the lens.
The image is enlarged and projected on the screen through the lens.

[0015] Focusing is performed by turning the projection lens facing the window in front of the case to move it forward and backward.

The liquid crystal light valve and the prism are cooled by a fan below the optical head unit.

The lamp housing unit is cooled by a fan provided near the lamp housing unit. The cooling air is also sent to the power supply unit on the side of the lamp housing unit to prevent the power supply unit from overheating.

The liquid crystal light valve driving control circuit unit is not affected by heat because it is arranged on the opposite side of the power supply unit, the lamp housing unit and the like. Further, since the control circuit unit is separated into an analog circuit unit and a digital circuit unit, interference between the units is avoided and noise is reduced.

The replacement of the projection light source lamp is performed by removing the lamp housing unit from the opening on the back of the case.

After replacing the lamp, when the lamp housing unit is placed in the opening, the lamp housing unit is correctly positioned in the outer housing.

The maintenance of each constituent unit including the lamp housing unit can be performed by opening the case and removing each unit from the base plate.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the liquid crystal projector of the present invention will be described below with reference to the drawings.

FIG. 1 is an external perspective view of a liquid crystal projector according to the present invention, in which a rectangular parallelepiped case 1 has all its components unitized for each function and accommodated.

As shown in FIG. 2, the rectangular parallelepiped case 1 is formed so as to be separable into a bottom plate 1A, a front plate 1B, a back plate 1C, and a top plate 1D integrated with both side plates. A pair of left and right threaded legs 2 for adjusting the projection direction up and down is provided at the front of the lower surface of the bottom plate 1A. Further, a ventilation slit 3 is opened in a portion located below an optical head unit to be described later.

A lens window 4 is opened at a position slightly closer to one side in the left-right direction from the center of the front plate 1B.
It is covered with a slide type cover plate 5 that moves in the horizontal direction, and the cover plate 5 escapes sideways when projecting. In the center of the front plate 1B, various adjustment knobs 6 for images and sounds are provided. A lamp housing unit insertion / removal opening 7 is opened at a position slightly away from the center of the rear plate 1C and on the side opposite to the side where the lens window 3 of the front plate 1B is open. It is covered by a panel provided integrally.

As shown in FIG. 3, a power supply connection outlet 8, a power supply on / off switch knob 9, and various signal input terminals 10 are provided on the back plate 1C.

As shown in FIG. 2, a pin leg 11 for positioning and a receiving cylinder 12 are provided at each corner of the top plate 1D and the bottom plate 1A.
The front plate 1D and the rear plate 1C are respectively fitted around the top plate 1D and the bottom plate 1A, which are assembled by fitting the pin legs 11 and the receiving cylinders 12, and fixed with screws or the like. Then, the case 1 is assembled.
A ventilation slit 13 is provided over a wide range at a position closer to the power supply unit side than the center of the top plate 1D. A speaker is mounted below the ventilation slit 13 but is omitted in the figure.

A base plate 14 is mounted on the bottom plate 1A with screws or the like so as to be removable.

The lamp housing unit 15, the light guide unit 16 and the optical head unit 17 are arranged on the base plate 14 so that the main optical path is L-shaped when viewed from above (see FIG. 9). 1
The projection lens 18 faces the window 4 on the front of the case, and the lamp housing unit 15 faces the opening 7 on the back of the case.

The power supply unit 19 is located outside the lamp housing unit 15 and the drive control circuit unit 20
Are disposed outside of the light guide unit 16, and the lamp housing unit 15, the light guide unit 16, the optical head unit 17, the power supply unit 19, and the drive control circuit unit 20 can be separately attached to and detached from the base plate 14. It is configured as follows.

The drive control circuit unit 20 includes an analog circuit part and a digital circuit part. Both circuits are separated and unitized, and one of the circuit units 201 is a light guide unit. 14
It is arranged on the upper surface of. And the optical head unit 1
A flat prober fan 21 is attached to the base plate 14 below the base plate 7, and blows outside air sucked from the ventilation slit 3 of the case bottom plate 1A to the optical head unit 17, and particularly cools the polarizing plate of the light valve. A space S (FIG. 9) surrounded by the light guide unit 16, the lamp housing unit 15, the one side surface 1E and the front surface 1B of the case 1 formed as a result of arranging the units so that the main optical path is L-shaped. ), The sirocco fan 22 is attached to the base plate 14, and the heat generated by the lamp housing unit 15 is forcibly exhausted from the ventilation slit 13 of the top plate 1 </ b> D with the flow of the outside air sucked from near the unit 15. . The heat of the power supply unit 19 and the air heated by cooling the optical head unit 1T are simultaneously exhausted.

FIG. 4 is an external perspective view of the lamp housing unit 15 and an outer housing 23 for housing and supporting the unit 15. The outer housing 23 is fixed to the base plate 14, and an opening 24 on the back faces the opening 7 of the case back plate 1C.

As shown in the exploded perspective views of FIGS. 4 and 5, the lamp housing unit 15 has a box-shaped frame 25A.
• The projection light source lamp 26 that allows halogen lamps is supported in 25B. Numeral 27 denotes a reflection / reception, in which a multi-mirror reflector is used for the purpose of improving brightness with a cold mirror as a measure against heat. 28 is a lamp socket, 29 is an ejector for removing the lamp, 30 is a light guide tube provided on the front side in the optical path direction of the box frame 25B, and 31 is a wind guide provided on the surface of the box frame 25B on the side of the sirocco fan 22. The tube 32 is a panel unit integrally provided on the back surface of the case of the box-shaped frames 25A and 25B. The panel portion 32 is larger than the opening 7 on the back of the case, and the lamp housing unit 15 is
3, the opening 7 is in the lamp housing unit 15
Is covered by the panel unit 32 of the first embodiment. Reference numeral 33 denotes a knob provided integrally with the panel portion 32. The knob 33 is used to take the lamp housing unit 15 in and out. 3
Reference numeral 4 denotes a lock member for the lamp housing unit 15 with respect to the case 1. The lock member operation knob 34A is located at the center of the knob 33.

The lamp housing unit 15 is supported at a point contact with the outer housing 23 to reduce the frictional resistance at the time of insertion and removal, and to improve the positioning accuracy. The positioning of the lamp housing unit 15 with respect to the outer housing 23, that is, the position of the projection light source lamp 26 is determined in the front-rear direction with respect to the optical path direction provided relatively to the outer surface of the box-shaped frame 25B of the lamp housing unit 15 and the inner surface of the outer housing 23. -It is determined by three springs 35 (see FIGS. 5 and 7) acting in each of the vertical and horizontal directions.

The outer housing 23 is also provided with a light guide tube 36 connected to the light guide tube 30 of the lamp housing unit 15, as shown in FIGS. Both light guide tubes 30 and 36 have mirror-finished inner surfaces to improve brightness and cooling efficiency.

When the lamp housing unit 15 is further housed in the outer housing 23, the unit 15 has a double structure, and a slit 37 provided in the panel portion 32 is provided.
The flow rate of the outside air sucked from the lamp housing unit 15 and flowing through the gap between the lamp housing unit 15 and the outer housing 23 is increased, and a part of the outside air entering through the slit 37 is reduced by the guide action of the air guide tube 31. The lamp housing unit 15 is sufficiently cooled because it flows accurately around the periphery 26. Therefore, the life of the lamp 26 is long and the case 1 is not overripened. Reference numeral 38 denotes a power cutoff thermal fuse provided for safety in case of overheating.

A heat ray cut filter I39 is superposed on the end face of the light guide tube 36 of the outer housing 23 on the light source lamp side, and is fixed by a holding plate 40. A mask 41 is formed on the end surface of the light guide tube 36 opposite to the light source lamp. 4
Reference numeral 2 denotes a connector to which the lamp socket 28 of the lamp housing unit 15 comes into contact and energizes.

FIG. 8 is an external perspective view of the light guide unit 16 and the optical head unit 17.

The light guide unit 16 includes a pair of upper and lower frame plates 44 and 45 having a U-shape in plan view and inner and outer side plates 46 and 47.
And a dichroic mirror system is incorporated in a light guide tube formed into a tubular shape. The inner surface of the light guide tube is mirror-finished to increase the reflectivity and suppress a decrease in brightness.

As shown in FIG. 9, the dichroic mirror system includes a blue reflecting dichroic mirror 14 from the light source 26 side.
8. A green reflecting dichroic mirror 49 and a normal reflecting mirror 50 are arranged in this order, and reflecting mirrors 51 and 52 are provided corresponding to the blue reflecting dichroic mirror 48 and the reflecting mirror 50 at the farthest positions, respectively.
The blue light reflected and diverted by the blue reflection guilloic mirror 48 and the red light reflected and diverted by the reflection mirror 50 are respectively diverted inward. When the color separation order is set as described above, the optical path length of blue light is short, and the optical path length of red light is long, thereby improving brightness, color reproducibility, and color balance.

An optical head unit 17 is disposed in a central space of the light guide unit 16 having a U-shape in plan view, and a light combining prism 53 and liquid crystal light valves 54, 55, and 56 disposed on three surfaces of the prism 53, respectively. ,
The light guide unit 16 matches the optical paths of the blue light, the green light, and the red light separated by the dichroic mirror system of the light guide unit 16.

The liquid crystal light valves 54, 55 and 56 are active matrix liquid crystal panels with a built-in driver and modulate a blue signal, a green signal and a red signal, respectively.

The prism 53 is formed by bonding two surfaces sandwiching the right angles of four right-angle prisms to each other so that the wavelength-selective reflection layers (blue reflection surface 57 and red reflection surface 58) are orthogonal to each other. It is a prism.

The separation / combination of light will be described with reference to FIG. 9. The blue reflecting mirror 48 reflects blue light and transmits other color lights. The reflected blue light changes its direction by the reflection mirror 51 and enters the blue modulation liquid crystal light valve 54.

The color light transmitted through the blue reflection mirror 48 is reflected on the green reflection mirror 49. The mirror 49 reflects only the green light and transmits the other red light. The reflected edge color light goes straight and enters the green modulation liquid crystal light valve 55.

The red light transmitted through the green reflecting mirror 49 changes its direction by a reflecting mirror 50 and then changes its direction by the next reflecting mirror 52 to enter a red modulation liquid crystal light valve 56.

Of the color light modulated by the light modulating means of each of the liquid crystal light valves 54, 55 and 56, blue light is reflected by the blue reflecting surface 57 of the prism 53 and red light is reflected by the red reflecting surface 58 of the prism 53. Reflected green light is prism 5
3 is transmitted straight through and mixed, and enters the lens 18 to form one color image which is enlarged and projected on the screen.

According to the above configuration, each image information obtained by the blue modulation liquid crystal light valve 54 and the red modulation liquid crystal light valve 56 is
8, the image information by the green modulation liquid crystal light valve 55 is not horizontally inverted. Therefore, the drive driver circuit is configured so that only the green modulation liquid crystal light valve 55 is horizontally inverted to display a composite image. Display is matched.

FIG. 10 is an exploded perspective view showing a specific structure of the optical head unit 17. As shown in FIG. Upper and lower and front and rear plates 59
A die-shaped loic prism 53 is provided at the center of a box frame formed by combining 60, 61, and 62 with left and right sides, and three springs 63 acting respectively in front and rear, left and right, and up and down.
(Only one is shown in the figure).

A front opening 61A of the front surface of the front plate 61 of the box frame.
The lens 18 is mounted in accordance with the position of the blue modulation liquid crystal light valve 5 after the left and right opening portions of the box-shaped frame and the back plate 62.
4. The red modulation liquid crystal light valve 56 and the green modulation liquid crystal light valve 55
It is mounted so that the left, right, front and back optical axes can be adjusted.

Each liquid crystal light valve 54, 55, 56
An insulating sheet 67 and a polarizing plate (not shown) are sandwiched between the front and rear support plates 65 and 66, and a slight gap is provided between the liquid crystal light valve and the front and rear plates. Further, on the lower side of each support plate 65 on the outside, a hook-shaped rectifying portion 65A which is opened outward is provided, and is placed below the optical head unit 17 as shown in an enlarged vertical sectional view of FIG. The outside air drawn into the case 1 by the fan 21 is guided to each of the liquid crystal light valves 54, 55, 56 without escaping to enhance the cooling effect. That is, the plate member itself supporting the liquid crystal light valve has a function of rectifying the cooling air.

Since the liquid crystal projector of the present invention has the above-described configuration, it is possible to display a large screen by enlarging and projecting an image obtained by mixing and mixing colors using a lens using at least three liquid crystal light valves for forming a color image. Necessary lamp housing unit, light guide unit, optical head unit consisting of light valve, photosynthetic prism and projection lens, and fan for cooling lamp housing and optical head unit, especially fan for cooling polarizing plate, etc. are compact in a rectangular parallelepiped case. Fits well, has good cooling efficiency and improves image quality. It is also possible to carry.

A power supply unit as well as each of the above functional units
Since the drive control circuit unit can be individually attached to and detached from the base plate in the case, assembly during production is simple and efficient, and productivity is improved. Also, maintenance and replacement for each unit is easy.

Since the drive control circuit unit is separated from the heat generating parts such as the power supply unit and the lamp housing unit, the drive control circuit unit is not affected by heat.

Further, since the drive control circuit unit is arranged separately for the analog circuit unit and the digital circuit unit, there is no mutual interference and no noise generation.

The projection light source lamp is often replaced. In that case, the lamp housing unit can be pulled out from the outer housing fixed inside the case without opening the case, and the lamp can be replaced.

Since the positioning is performed when the lamp housing unit is inserted into the outer housing, there is no need to adjust the optical axis later, and the operability is excellent.

[0058]

As described above, according to the present invention, it is possible to prevent the case in which the strong light source lamp of the projector overheats the inside of the case and damage the lamp, damage the members in the case, or deteriorate the characteristics.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a projector according to the present invention.

FIG. 2 is an exploded perspective view showing a case.

FIG. 3 is an external perspective view seen from the back side.

FIG. 4 is a perspective view of a state where the lamp housing unit is taken out of the housing.

FIG. 5 is an exploded perspective view of the lamp housing unit.

FIG. 6 is an exploded perspective view of an outer housing.

FIG. 7 is a diagram of the outer housing as viewed from a surface on a side where a lamp housing unit is taken in and out;

FIG. 8 is an external perspective view of a light guide unit and an optical head unit.

FIG. 9 is a plan view for explaining an arrangement of each unit in the case and an outline of an optical path.

FIG. 10 is an exploded perspective view of the optical head unit.

FIG. 11 is an enlarged vertical sectional front view of a main part of the optical head unit.

[Explanation of symbols]

1 ... rectangular case lA ... bottom plate lB ... front plate lC ... back plate lD ... top plate lE · IF ... side surface 4 ... front window 7 ... back opening Reference numeral 14: Peace plate 15: Rambu housing unit 16: Light guide unit 17: Optical head unit 18: Projection lens 19: Power supply unit 20: Drive control circuit unit 21: ..Optical head unit cooling fan 22 ... Lamp housing unit cooling fan 23 ... Outer housing of lamp housing unit 26 ... Projection light source 53 ... Photocomposite prism 54.55.56 ... Liquid crystal Light valve S ・ ・ ・ Vacancy

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[Procedure amendment]

[Submission date] April 8, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005]

In order to achieve the above object, a liquid crystal projector according to the present invention is a projector for projecting modulated light of light from a light source lamp, wherein a temperature fuse is arranged near the light source lamp. The thermal fuse is a fuse for shutting off power when the inside of the projector case is overheated by the light source lamp. Further, a cooling fan for the light source lamp is arranged near the light source lamp.

Claims (2)

[Claims] In a projector for projecting light modulated based on light from a light source lamp, a temperature fuse is arranged near the light source lamp, and the temperature fuse heats the inside of the projector case by the light source lamp. A projector characterized in that the power supply is shut off when the power is turned off. 2. The projector according to claim 1, wherein a cooling fan for the light source lamp is arranged near the light source lamp.