JP2003241314A - Projection type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of a turbulent flow of cooling air in an air cooling space in which a light valve unit is accommodated. <P>SOLUTION: In a liquid crystal projector, four ventilation guides 61A, 61B, 61C and 61D are vertically provided at four corners 41a of the air cooling space 41 in which the light valve unit 24 is accommodated. Three cooling air discharge holes 60R, 60G and 60B opposed to the upper part of three cooling air blowoff ports at the lower part are arranged at the outer circumference portion of a filter holder 44 holding a filter 45 for falling dust. <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 projection type display device suitable for application to a liquid crystal projector, and in particular, it has three wavelengths of red, green, and blue in the light emitted from a light source section. The present invention belongs to the technical field of cooling a light valve unit including three sets of an incident side polarization plate, a light valve and an emission side polarization plate, which obtains three color images by respectively modulating light in the bands.

[0002]

2. Description of the Related Art Conventionally, in a liquid crystal projector which is an example of a projection type display device, red, green, and green light obtained by making light emitted from a light source unit such as a power lamp enter a light valve such as a liquid crystal panel, A full-color image is displayed by projecting an image of blue or the like on a screen or the like by a projection lens. In a liquid crystal projector, various optical components that become hot during driving, for example, a light valve unit including three sets of light valves and incident side and emission side polarizing plates are cooled by cooling air blown from a cooling fan. The heat generated by the power lamp or the like is exhausted to the front side (image projection side) of the outer casing by the exhaust fan so that these heat-generating components are kept below the guaranteed temperature limit.

At this time, as shown in FIGS. 16 to 18, conventionally, the light valve unit air cooling device has been constructed as follows. That is, the light valve unit 111 housed in the optical unit case 110 has three sets of vertical incident sides arranged in parallel to the three surfaces of the cross prism 112 except the front surface side which is the projection lens 113 side. Polarizing plates 114R, 114G, 114B, light valve 1
15R, 115G, 115B and exit side polarization plate 116
R, 116G, 116B are provided. The incident side polarization plates 114R, 114G and 114B are adhered to the glass plate 117, and the emission side polarization plates 116R, 116G and 1B.
16B is adhered to the glass plate 117 or the cross prism 112. Further, an air cooling space 118, which is a substantially rectangular and vertical space cut out in a substantially U shape, is provided at a position on the front side of the optical unit case 110 behind the projection lens 113. There is. The light valve unit 11 is provided at the center of the air cooling space 118.
1 is vertically inserted by a light valve unit holder made of sheet metal or the like (not shown) integrally with the cross prism 112, and has a horizontal light valve mounting portion 11 at the bottom.
9 and the cross prism 112 is a projection lens 1
It is arranged on 13 optical axes. In addition, the filter holder 120 of the optical unit case 110 covers the center upper part of the air-cooling space 118 with a dust-falling filter 121 having air permeability which is horizontally attached to the center of the filter holder 120 having a substantially frame shape. It is mounted horizontally on the top.

In the light valve mounting portion 119, three pairs of cooling air outlets 122 each having a pair of six long holes are provided.
R, 122G, and 122B are formed in a U shape along the periphery of the cross prism 112, and these three sets of cooling air outlets 122R, 122G, and 122B are three sets of incident side polarization plates 114R, 114G, and 114B, respectively. Between the light valves 115R, 115G and 115B and between the light valves 115R, 115G and 115B and the emission side polarization plate 11
It is formed in parallel with 6R, 116G, and 116B. On the other hand, the sirocco fan 123 is used as a cooling fan.
The cooling air outlet 125 is connected via a duct joint 128 to a ventilation duct 126 horizontally attached to the lower portion of the light valve mounting portion.

When the liquid crystal projector is driven,
The sirocco fan 123 is operated at the same time to pressurize the cooling air CW that is the outside air sucked in from the cooling air outlet 124 to apply the duct joint 128 from the cooling air outlet 125.
Air is blown into the air duct 126 through the air duct 126, the cooling air CW is divided into three systems by the three air passages 127 in the air duct 126, and three sets of cooling air outlets 121R, 121G, 1 are provided.
21B is blown upward into the air-cooling space 118.
Then, the cooling air CW divided into these three systems is applied to the three sets of incident side polarization plates 114R, 1R of the light valve unit 111.
14G, 114B, light valves 115R, 115G,
115B and exit side polarization plates 116R, 116G, 116
Raised along the surface of B, these surfaces are cooled, keeping them below the guaranteed temperature. The cooling air CW that has risen in the air-cooling space 118
Passes through the dust drop prevention filter 121 on the upper part and is discharged to the upper part of the optical unit case 110.

[0006]

However, conventionally, there are three sets of cooling air outlets 121R and 121G arranged at three locations around the cross prism 112 in the lower portion of the air cooling space 118 of the optical unit case 110. , 121B, the cooling air CW blown upward is transmitted through the dust fall prevention filter 121 arranged in the center of the upper portion of the air-cooling space 118 and is discharged to the upper portion of the optical unit case 110. , A fine dust (about 10 to 50 μm) mixed in the cooling air CW and blown into the air-cooling space 118, which cannot be removed by an intake filter (not shown) of the liquid crystal projector, is a dust fall prevention filter. It is easy to be attached and deposited on 121. When the fine dust adheres to and is accumulated on the dust drop prevention filter 121, the cooling air CW discharged from the upper portion of the air cooling space 118 to the upper portion of the optical unit case 110.
Exhaust efficiency becomes worse. In addition, three sets of incident side polarization plates 114R, 114G, 114B in the air cooling space 118,
4 between the light valves 115R, 115G, 115B and the exit side polarization plates 116R, 116G, 116B.
Since the three corner portions 118a are widely opened, three sets of cooling air outlets 122R, 122G, 122B are provided.
The cooling air CW blown upward from the lower part of the air-cooling space 118 to the lower surface 115a of the three light valves 115R, 115G, 115B having a large thickness (about 5 mm), the lower surface 117a of the glass plate 117, and The flow direction was irregularly changed by hitting the light valve unit holder or the like, and it was easy to irregularly flow into the four greatly opened corner portions 118a of the air-cooling space 118. Then, turbulent flow TM accompanied by a large amount of vortices was generated in the cooling air CW that irregularly flowed into the four corner portions 118a. The generation of the turbulent flow TM of the cooling air CW in the air-cooling space 118 has been verified by an air blowing analysis through experiments.

Then, the cooling air C is introduced into the air cooling space 118.
When the turbulent flow TM of W is generated, the fine dust DS mixed in the cooling air CW is separated from the cooling air CW in the air cooling space 118 and is separated into four corners in the air cooling space 118. It remains and is deposited on the portion 118a and the like. Then, the fine dust DS remaining and accumulated in the air-cooling space 118 is stirred again by the turbulent flow TM of the cooling air CW and rises up, and the light valves 115R, 115G, 115.
The vicious cycle of B and the incident / exit side polarization plates 114R, 114G, 114B and 116R, 116G, 116B is repeated. Then, the fine dust DS forms the cross prism 112, the light valve 115R,
115G, 115B and entrance / exit side polarization plates 114R, 114
If it adheres to the surface of G, 114B and 116R, 116G, 116B, there is a problem that an adverse effect such as color disorder occurs in the projected image.

The present invention has been made to solve the above problems, and prevents turbulent flow of cooling air from occurring in the air-cooling space in which the light valve unit is housed, and blows air. It is an object of the present invention to provide a projection type display device capable of improving efficiency.

[0009]

A projection type display device of the present invention for achieving the above object is provided with a dust fall prevention filter on an upper portion of an air cooling space in which a light valve unit of an optical unit case is accommodated. The cooling air outlets are provided at three positions of the mounted filter holder, which are three positions corresponding to the upper portions of the cooling air outlets that are opened at the bottom three positions of the air cooling space. 4 in the department
Vertical ventilation guides are provided at the four corners, and the cooling air blown upward from the cooling air outlets that are opened at the bottom three places of the air cooling space is provided at the four corners of the air cooling space. Guide it upwards with a blower guide,
After the cooling air is raised along the surfaces of the three sets of the incident side polarization plate, the light valve, and the emission side polarization plate, it is discharged to the upper side of the optical unit case from the three cooling air discharge ports right above. It is composed.

In the projection type display device of the present invention having the above-described structure, the cooling air blown upward from the three cooling air outlets at the lower part of the air cooling space is placed in the air cooling space. By guiding the cooling air upward by the vertical air guides provided at the four corners, the cooling air is smoothly raised along the surfaces of the three sets of the incident side polarization plate, the light valve and the emission side polarization plate, The cooling air can be smoothly discharged to the upper side of the optical unit case from the three cooling air outlets formed on the filter holder and directly above the three cooling air outlets. Turbulence does not occur.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a liquid crystal projector to which the present invention is applied will be described below with reference to FIGS.
The description will be given in the following order. (1) ... Explanation of liquid crystal projector as a whole (FIGS. 1 to 6) (2) ... Outline of light valve unit air cooling device (FIGS. 4 to 9) (3) ... Light valve unit air cooling device (FIG. 10 to FIG. 14) regarding the structure of the air blow guide in FIG. 4 (4) .....

(1) Description of Entire Liquid Crystal Projector First, an entire liquid crystal projector, which is an example of a projection type display device, will be described with reference to FIGS. The outer casing of the liquid crystal projector 1 is configured in a flat box shape, and the liquid crystal projector 1 is used by being placed on a desk or the like by a stand 3 (see FIG. 5) provided on the bottom surface 2e of the outer casing 2. A hanging member (not shown) provided on the upper surface 2f of the outer casing 2 is configured to be used by being hung on the ceiling or the like in the room.

Next, inside the outer casing 2, there is arranged an optical unit case 4 which is made of synthetic resin or the like and is bent into an L-shape in plan view. Inside the optical unit case 4, each optical unit case 4 is arranged. An optical unit composed of optical parts is stored. This optical unit includes a power source lamp 5 which is a light source unit, fly-eye lenses 6 and 7, a PS conversion element 8, a condenser lens 9, a total reflection mirror 10, dichroic mirrors 11R, 11G and 11B, a relay lens 12, and a total reflection mirror 13. , Relay lens 14, total reflection mirrors 15 and 16, field lenses 17R and 17G,
17B, incident side polarization plates 18R, 18G and 18B, light valves 19R, 19G and 19B which are liquid crystal panels, emission side polarization plates 20R, 20G and 20B and cross prism 2.
It is composed of 1 etc.

The power source lamp 5, which is a lamp unit constituting the light source section, has a discharge tube 5a concentrically attached to the center of a substantially conical reflector 5b. In addition, the fly-eye lenses 6 and 7 arranged at intervals divide the light emitted from the power source lamp 5 with a non-uniform luminance distribution into a large number of luminous fluxes, and thus the surfaces of the light valves 19R, 19G and 19B. It has a function of making the luminance distribution of the light that illuminates the entire surface uniform. Then, the fly-eye lens 6 on the incident side is arranged close to the power supply lamp 5 side, and the PS conversion element 8 is arranged close to the fly-eye lens 7 on the emitting side. The PS conversion element 8 is composed of a polarization beam splitter arranged in a strip shape and a phase difference plate intermittently provided corresponding thereto, and has a function of converting the polarization direction of incident light. ing.

The total reflection mirror 10 is arranged on the opposite side of the PS conversion element 8 with the condenser lens 9 interposed therebetween, and reflects light by 90 ° to dichroic mirror 11.
It has the function of leading to R and 11G. Then, the dichroic mirrors 11R and 11G are turned in the same direction, respectively.
The dichroic mirror 11R is arranged so as to be inclined by 90 °, and the dichroic mirror 11R reflects the light in the red wavelength band by 90 °, and the dichroic mirror 11G reflects the light in the green wavelength band by 90 °. It has a function.

The total reflection mirror 15 is arranged in front of the dichroic mirror 11R and has a function of reflecting the light in the red wavelength band reflected by the dichroic mirror 11R and guiding it to the field lens 17R. And
A relay lens 12 and a total reflection mirror 13 are separately arranged on the side of the dichroic mirror 11G, and a relay lens 14 is provided in front of the total reflection mirror 13.
And the total reflection mirror 16 are arranged separately from each other. These total reflection mirrors 13 and 16 detect light in the blue wavelength band transmitted through the dichroic mirror 11G.
It has a function of reflecting and guiding to the field lens 17B.

The field lenses 17R, 17G,
Incident side polarization plates 18R and 18R are provided on the emission side of 17B, respectively.
G, 18B, light valves 19R, 19G, 19B and emission side polarization plates 20R, 20G, 20B are arranged in parallel at a predetermined interval and vertically. And
These incident side polarization plates 18R, 18G and 18B, the light valves 19R, 19G and 19B and the emission side polarization plates 20R,
Reference numerals 20G and 20B denote three vertical incident surfaces 21R and 21 on the left and right side surfaces and the rear surface of the rectangular parallelepiped cross prism 21.
They are arranged in a substantially U-shape in three directions facing G and 21B. At this time, the incident side polarization plates 18R, 18G, 18B
Are light valves 19R and 19R of the glass plate 22, respectively.
G and 19B are adhered to the light polarizing plates 20R, 20G, and 20B on the side of the light valves 19R, 19G, and 19B of the glass plate 23 by adhesion or the like. The prism 21 is directly attached to the three incident surfaces 21R, 21G, and 21B by adhesion or the like.

Then, incident side polarization plates 18R, 18G, which are arranged in a substantially U-shape on the outer periphery of the cross prism 21,
18B, the light valves 19R, 19G and 19B and the exit side polarization plates 20R, 20G and 20B constitute a light valve unit 24 having a substantially U shape as a whole, and the light valve unit 24 is provided around the cross prism 21. They are integrally connected by a unit frame (not shown) made of sheet metal or the like. The tip 25a of the projection lens 25 arranged in front of the front surface GF of the cross prism 21 is exposed to the front surface 2a of the outer casing 2.

By the way, the optical unit case 4 is the outer casing 2
Is housed at a position offset to the right side surface 2b, etc. inside the housing, and inside the outer casing 2, at a position displaced to the left side surface 2c etc., a power circuit for setting and a power circuit for power lamps. The power supply board 26 on which is mounted is accommodated horizontally. Then, at the position of the front surface 2a inside the outer casing 2,
Right side position of the projection lens 25 (on the side opposite to the power lamp 5)
The cooling fan 27 is arranged at the position of, and the two exhaust fans 28 and 29 are arranged at the front position of the power lamp 5 and the front position of the power board 26. In addition, on the left side surface of the optical unit case 4, the fly-eye lens 7 and the PS
A cooling fan 30 is also arranged in the vicinity of the conversion element 8. Then, the cooling fan 2 is provided on the side surface 2b of the outer casing 2.
Air inlets 31 and 32 are formed in the lateral position of 7 and the rear surface 2d of the outer casing 2, and the front surface 2a of the outer casing 2 is formed.
The exhaust ports 33, 34 are formed in front of the two exhaust fans 28, 29.

Here, a full-color image projection operation by the liquid crystal projector 1 (hereinafter referred to as driving)
Will be described.

The white light emitted by turning on the discharge tube 5a of the power lamp 5 is reflected by the reflector 5b to become substantially parallel light, and this white light is emitted along the optical axis P1. Then, this white light is formed into uniform white light with no brightness unevenness by the fly-eye lenses 6 and 7 composed of a large number of small lenses. That is, after the substantially parallel light of the white light is divided into a large number of light fluxes by the large number of lenses of the first-stage fly-eye lens 6, the large number of light fluxes corresponds to a large number of corresponding lenses of the second-stage fly-eye lens 7. Of the condensed light, and a large number of the condensed light is transmitted through the PS conversion element 8 to be polarized and converted, and at the same time, the condenser lens 9
By condensing so as to illuminate the area corresponding to the liquid crystal panel surface, uniform white light with no brightness unevenness is formed. Then, the uniform white light without the brightness unevenness is transmitted through the optical axis P.
The light is incident and illuminated substantially uniformly on the entire surfaces of three light valves 19R, 19G, and 19B, which will be described later, via 1, P2, P3, P4, P5, P6, and P7.

At this time, the white light is reflected and / or transmitted through the color separation means composed of the total reflection mirror 10 and the dichroic mirrors 11R and 11G, whereby the wavelength band is red light R and green light. It is divided into three color lights of G and B which is blue light (hereinafter, red light, green light and blue light are simply referred to as R, G and B). First, the white light is reflected by the total reflection mirror 10 to change its traveling direction from the optical axis P1 to the optical axis P2 by 90 °, and then enters the first-stage dichroic mirror 11R. The first-stage dichroic mirror 11R reflects R to change the traveling direction by 90 ° to the optical axis P3, while transmitting G and B. Then, the first-stage dichroic mirror 11R
R reflected by the total reflection mirror 15 is reflected by the optical axis P
90 ° to 4 Change the direction of travel.

Then, the first-stage dichroic mirror 1
G and B transmitted through 1R are incident on the second stage dichroic mirror 11G on the optical axis P2. The second-stage dichroic mirror 11G reflects G and reflects the optical axis P5.
The direction of travel is changed to 90 ° while passing through B. Then, B which has passed through the second-stage dichroic mirror 11G is reflected by the total reflection mirror 13 to convert the traveling direction from the optical axis P2 to the optical axis P6 into 90 °, and then passes through the relay lens 14, and further, Reflected by the total reflection mirror 16,
The traveling direction is changed by 90 ° from the optical axis P6 to the optical axis P7.

Then, in this way, the colors are separated,
R, G, B incident on optical axes P4, P5, P7 in three directions
The three lights of are the field lenses 17R and 17R, respectively.
The light is collected by G and 17B, transmitted through the three incident side polarization plates 18R, 18G and 18B of the light valve unit 24, and incident on the incident surfaces of the three light valves 19R, 19G and 19B, respectively.

At this time, the three R, G, and B lights are polarized in the same direction by the three incident side polarization plates 18R, 18G, and 18B, and the three light valves 19R, 19G, and 1 are arranged.
The light is incident on the incident surface of 9B. Then, the three light valves 19R, 19G, and 19B are modulated by the image signal applied corresponding to each wavelength band, and the polarization plane of light is rotated. For the three lights R, G, and B whose polarization planes are rotated, these three light valves 19R, 19G, 19
Image light is obtained by transmitting a predetermined polarization component by each of the exit side polarization plates 20R, 20G, and 20B of B, and these three image lights of R, G, and B are three surfaces 21R, 21G, of the cross prism 21. 21B has three optical axes P4,
It is incident from P5 and P6, respectively.

The cross prism 21 reflects the R and B image lights at 90 ° by the two reflecting surfaces 21a and 21b which are orthogonal to each other, and the G image light is reflected by the two reflecting surfaces 21a and 21b.
The three prisms R, G and B are combined by the cross prism 21 so that they are transmitted by a and 21b. Then, the combined three image lights of R, G, and B are incident on the projection lens 25 on the optical axis P5, and are projected on a projection surface (not shown) such as a screen by the projection lens 25 to obtain a full-color image. Will be projected on the projection surface.

When the liquid crystal projector 1 is driven, the light valve unit 2 which is the first heat generating portion
In 4, the three incident-side polarization plates 18R, 18G, and 18B absorb light other than a certain direction in order to align the polarization directions of the three lights R, G, and B, respectively. Generate heat respectively. The three light valves 19R, 19G, and 19B are R, G, and B, respectively.
The image signal (voltage) applied corresponding to each wavelength band of one light modulates three lights by changing the vibration direction of the liquid crystal molecules, and rotates the plane of polarization of the light.
The liquid crystal molecules generate heat as they are vibrated. Furthermore, three outgoing side polarization plates 20R, 20G, 20B
Will transmit only three lights of R, G, and B whose polarization planes are rotated in a certain direction and absorb other lights.
Each absorbs the light to generate heat.

Therefore, when the liquid crystal projector 1 is driven, three sets of incident side polarization plates 18R, 18G, 18B of the light valve unit 24, and light valves 19R, 19 are arranged.
It is necessary to forcibly air-cool the surfaces of G, 19B and the exit side polarizing plates 20R, 20G, 20B to keep them at the limited guarantee temperature or lower.

Further, when the liquid crystal projector 1 is driven, the power lamp 5, which is the second heat generating portion, generates high heat due to lighting of the discharge tube 5a. Further, the power supply board 26, which is the third heat generating portion, generates heat by the mounted heat generating components such as the condenser, the IC, and the power supply transformer. Therefore, when the liquid crystal projector 1 is driven,
Along with the light valve unit 24, it is necessary to forcibly air-cool the power-generating lamps on the power-source lamp 5 and the power-supplying board 26 to keep them below the limited guarantee temperature.

(2) Outline of Light Valve Unit Air-Cooling Device Next, an outline of the light valve unit air-cooling device 40 will be described with reference to FIGS. However, in FIG. 4 to FIG. 9, in order to make it easy to understand the outline of the air cooling structure, the blower guide structure described later is removed and shown. First,
As shown in FIG. 4 to FIG. 9, the light valve unit air-cooling device 40 has a substantially rectangular shape that is cut out in a substantially U-shape at the rear position of the projection lens 25 and at the front side position of the optical unit case 4. It has an air cooling space 41 which is a vertical space. The bottom of the air cooling space 41 is formed in the horizontal light valve unit mounting portion 42, and the light valve unit 24 described above is integrated with the cross prism 21 by the unit frame (not shown). It is housed in the center of the portion 41 and mounted vertically on the light valve unit mounting portion 42. The optical axis P5 of the light valve unit 24 is aligned with the optical axis P8 of the projection lens 25.

At this time, the light valve unit mounting portion 42
Is made of aluminum die casting or the like, and a rear end of the horizontal projection lens 25 is attached to a lens mounting portion 42a integrally formed vertically in the upper portion on the front end side thereof, and the rear end of the projection lens 25 is Front 21F of the cross prism 21
Being close to.

The light valve unit mounting portion 42
At three positions on the outer periphery of the cross prism 21 excluding the projection lens 25 side, at a position corresponding to the lower portion of the substantially U-shaped light valve unit 24, a pair of cooling air blowers, a total of six cooling air blowers. The outlets 43R, 43G, 43B are formed in a substantially U shape. These three sets of cooling air outlets 43
R, 43G and 43B are incident side polarization plates 18R and 18R, respectively.
G and 18B and the respective light valves 19R, 19G and 19B, the positions directly below, and the respective light valves 19R, 19G and 1
9B and each of the output side polarization plates 20R, 20G, and 20B, and the positions directly below them.
The pair of cooling air outlets 43R, 43G, 43B are incident side polarization plates 18R, 18G, 18B and the light valve 19, respectively.
R, 19G, 19B and exit side polarization plates 20R, 20G,
It is formed in a long hole shape along 20B.

A dust drop prevention filter 45 having air permeability is attached to the center of the filter holder 44 formed of synthetic resin or the like in a frame shape so as to cover the upper center of the air cooling space 41. A holder 44 is detachably attached to the upper part of the optical unit case 4 and mounted horizontally.

The cooling fan 27 is composed of a sirocco fan 47, and the sirocco fan 47 is mounted vertically in parallel with the projection lens 25. This sirocco fan 47 has a substantially spiral housing 4
A rotary blade 50 that is rotated integrally with a rotor 49 of a motor (not shown) is provided at an eccentric position in FIG. 8, and the rotary blade 50 has a large number of radial sirocco fan blades 5.
0a is provided. An annular intake port 51 opened on the outer side surface of the housing 48 is arranged concentrically with the rotary vane 50, and an exhaust port 52 is opened so as to be narrowed down to the end of the outer periphery of the substantially spiral housing 48. Has been done. The intake port 51 is close to the intake port 31 on the right side surface 2b of the outer casing 2 shown in FIG.

The light valve unit mounting portion 42
3 sets of cooling air outlets 43R, 43G, 43B in the lower part of the
A blower duct 54 having a shape that covers the entire lower part is removable and is attached horizontally. And Sirocco fan 4
The exhaust port 52 of No. 7 is connected to the air blow duct 54 via a duct joint 56. The blower duct 54 is formed of synthetic resin or the like, and three sets of cooling wind blowout ports 43R, 43G, and 4 are provided in the blower duct 54.
3 sets of ventilation passages 55R and 55 for respectively blowing air to 3B
G and 55B are formed. Further, it is designed such that the air volume of the cooling air blown by these blow passages 55R, 55G, 55B increases in the order of the blow passages 55R, 55G, 55B.

The light valve unit air cooling device 40 operates the sirocco fan 47 at the same time when the liquid crystal projector 1 is driven, so that the cooling air CW, which is the outside air, is removed by the rotating blades 50 that are rotated integrally with the rotor 49. Intake is performed through the intake port 51 from the intake port 31 of the housing 2.
Then, the cooling air CW is pressurized in the housing 48 by the rotary vanes 50 and discharged from the exhaust port 52 to the air blowing duct 54 through the duct joint 56.
3 sets of ventilation passages 55R, 55G, 5 of the ventilation duct 54
5B to guide 3 sets of cooling air outlets 43R, 43G, 4
Blow upward from 3B to the lower part of the air cooling space 41.

Then, the three sets of cooling air outlets 43R,
The cooling air CW blown out from 43G and 43B is applied to the three sets of incident side polarization plates 18R and 18 of the light valve unit 24.
G, 18B, the light valves 19R, 19G, 19B and the exit side polarization plates 20R, 20G, 20B are moved up in the air cooling space 41, and the cooling air CW causes the light valve unit 24 to move to 3 A pair of incident side polarization plates 18R, 18G, 18B and light valves 19R, 19
The surfaces of G, 19B and the exit side polarization plates 20R, 20G, 20B are forcibly air-cooled, and these are kept below the limited guarantee temperature. As will be described later in the following section “(3) ... Description of air guide structure of light valve unit air-cooling device”, the air-cooling space 41 is provided.
The cooling air CW rising inside is discharged to the inside of the outer casing 2 above the optical unit case 4.

When the liquid crystal projector 1 is driven, the cooling fans (sirocco fan 47) 27 and the exhaust fans 28 and 29 and the cooling fan 30 are operated at the same time. Then, the cooling air which is the outside air is sucked into the outer casing 2 through the air inlet 31 shown in FIG. 2, and the cooling air is blown into the light emitting side of the power supply lamp 5 in the optical unit case 4 by the cooling fan 30. The high temperature heat generated by the power supply lamp 5 is exhausted by the exhaust fan 18 as shown in FIG.
The power lamp 5 is forcibly air-cooled by exhausting air to the front of the outer casing 2 from 3. And at the same time, the power supply board 2
2 shows the heat generated by heat-generating components such as a condenser, an IC, and a power transformer mounted on 6 and the hot air discharged into the outer casing 2 from above the optical unit case 4 from inside the air cooling space 41. By exhausting air from the illustrated exhaust port 34 to the front of the outer casing 2, heat generating components such as the condenser, IC, and power transformer of the power supply substrate 26 are forcibly air-cooled, and the heat generating components of the power supply lamp 5 and the power supply substrate 26 are limited. It is kept below the guaranteed temperature.

(3) Description of Blower Guide Structure in Light Valve Unit Air-Cooling Device Next, a blower guide structure in the light valve unit air-cooling device will be described with reference to FIGS. First, it is equivalent to the upper part of the cooling air outlets 43R, 43G, 43B that are opened at three locations on the outer peripheral portion 44a of the filter holder 44 and at three locations on the light valve unit mounting portion 42 that is the bottom of the air cooling space 41. Cooling air discharge ports 60R, 60G, and 60B for discharging the cooling air CW are formed above the optical unit case 4 at three positions.

Next, four air blow guides 61A, 61 are provided on the four corner portions 41a of the air cooling space 41 which is formed in a substantially rectangular shape and is vertical in the optical unit case 4.
B, 61C and 61D are arranged vertically. At this time, the two blower guides 61A and 61B are formed so that the horizontal shear cross-section is substantially L-shaped.
C and 61D are formed to have an almost I-shaped horizontal shear cross section. And these four blower guides 61A, 61B,
61C and 61D are three sets of incident side polarization plates 18R, 18G and 18B of the light valve unit 24, and the light valve 19 respectively.
R, 19G, 19B and exit side polarization plates 20R, 20G,
It is arranged in parallel with and close to both side surfaces of 20B.

Incidentally, these four blower guides 61A, 6
1B, 61C and 61D can be integrally formed on the optical unit case 4 or the light valve unit mounting portion 42 or can be detachably attached to these. Also, FIG.
As shown in FIG. 1, these four blower guides 61A, 61A
B, 61C, and 61D are integrally formed on the lower surface of the filter holder 44 formed of synthetic resin or the like, and the four air guides 61A and 61 are formed by the filter holder 44.
It is also possible to detachably attach B, 61C, and 61D to the four corner portions 41a in the air cooling space 41.

As described above, the air blowing guide mechanism of the light valve unit air-cooling device 40 has three air blowing outlets 60R, 60G, 60B and four air blowing guides 61A, 6A.
1B, 61C, 61D. Then, as shown in FIGS. 7, 8, 13 and 14, when the light valve unit 24 is forcibly cooled by air, the sirocco fan 47 causes the duct joint 56 and the blower duct 5 to operate.
4 through 3 cooling air outlets 43R, 43G, 43
The cooling air CW blown upward from B to the lower portion of the air-cooling space 41 is provided with four vertical air guides 61A,
It is possible to smoothly guide upward between 61B, 61C, and 61D.

That is, the three cooling air outlets 43R, 43
Part of the cooling air CW blown upward from G and 43B is the lower surface 19a of the light valves 19R, 19G and 19B.
And lower surfaces 22a and 23a of the glass plates 22 and 23, and further,
The light valve unit 24 hits a light valve unit holder or the like (not shown) of the light valve unit 24, and the air cooling space 4
Although it tries to flow irregularly into the four corner portions 41a in 1, the four air blow guides 61A, 61B, 61C, 61D are vertically arranged in the four corner portions 41a, so that cooling is performed. Part of the wind CW cannot flow into the four corner portions 41a.

Therefore, the three cooling air outlets 43R, 4
The cooling air CW blown upward from the 3G and 43B to the lower portion of the air-cooling space 41 does not flow into the four corner portions 41a, and the four air guides 61A and 61 are provided.
B, 61C and 61D are smoothly guided, and three sets of incident side polarization plates 18R, 18G and 18B and the light valve 1 are provided.
9R, 19G, 19B and exit side polarizing plates 20R, 20
It can rise smoothly along the surface of G and 20B.

Then, three sets of the radiation side polarization plates 18R and 18R
G, 18B, the light valves 19R, 19G, 19B and the exit side polarization plates 20R, 20G, 20B are mostly formed in the filter holder 44 along the surfaces of the cooling air CW that has been raised to the upper part of the air cooling space 41. And the three cooling air outlets 60R, 60 are provided at positions corresponding to the upper portions of the three cooling air outlets 43R, 43G, 43B.
G and 60B are smoothly discharged into the outer casing 2 directly above the optical unit case 4. It should be noted that only a part of the cooling air CW that has risen to the upper portion of the air-cooling space 41 passes through the dust drop prevention filter 45, and is discharged into the outer casing 2 above the optical unit case 4. Become.

As described above, the air guide structure of the light valve unit air-cooling device 40 is designed so that the air-cooling space 41 is upwardly extended from the three cooling air outlets 43R, 43G, 43B at the bottom of the air-cooling space 41. Blown cooling air C
W is guided by the four blower guides 61A, 61B, 61C, 61D arranged at the four corner portions 41a to be smoothly raised, and the cooling air outlets 4 at the three locations
3R, 43G, and 43B, the upper part of the cooling air discharge ports 60R, 60G, which are arranged facing each other.
Since it is configured to smoothly discharge upward from 60B, the four corner portions 4 in the air cooling space 41 are
The turbulent flow TM described in FIGS. 16 to 18 does not occur in 1a.

As described above, according to the id structure for the air blowing of the light valve unit air cooling device 40, the air cooling space 4 is formed.
Cooling air outlets 43R, 43G, 43B at three lower portions of 1
The cooling air CW blown upward from below into the air cooling space 41 is smoothly generated upward from the cooling air discharge ports 60R, 60G, 60B in the upper three locations without generating turbulence. Can be released to
Fine dust (dust) of about 10 to 50 μm that cannot be removed by the suction filter (not shown) of the liquid crystal projector 1 and is mixed with the cooling air CW and sucked
Can be smoothly discharged together with the cooling air CW from the cooling air discharge ports 60R, 60G, 60B at the three upper portions to above the air cooling space 41. Therefore, the fine dust is unlikely to adhere and accumulate in the air-cooling space 41, and the fine dust is not rolled up and scattered by the cooling air.

Therefore, fine dust is scattered in the air-cooling space 41, and three sets of incident side polarization plates 18R, 18G and 18 are arranged.
B, the surfaces of the light valves 19R, 19G and 19B and the exit side polarization plates 20R, 20G and 20B and the cross prism 2.
It is possible to prevent the adverse effect of adhering to the one incident surface 21R, 21G, 21B or the like and causing color disorder in the projected image, and to significantly improve the image quality of the projected image.

Further, since the amount of the cooling air that passes through the dust drop prevention filter 45 and is discharged to the upper part of the air cooling space 41 and to the outside can be suppressed to a very small part, the fine air mixed in the cooling air CW can be suppressed. Dust is rarely attached to and accumulated on the dust drop prevention filter 45, and high ventilation efficiency of the cooling air CW in the air-cooling space 41 can be maintained, so that three sets of incident side polarization plates 18R, 18G, 18B, light valves 19R, 19G, 19B and exit side polarization plate 20.
The cooling efficiency of R, 20G, and 20B can be improved, and these can be safely kept below the guaranteed temperature limit.

When the air blower of the light valve unit air-cooling device 40 has an id structure, four air blow guides 61 are provided.
By integrally molding A, 61B, 61C and 61D to the optical unit case 4 or the filter holder 44,
The structure and assembly of the liquid crystal projector 1 can be simplified, and the manufacturing cost can be reduced. In particular, when the four blower guides 61A, 61B, 61C, 61D, the filter holder 44, and / or the blower duct 54 are detachably attached to the optical unit case 4, the liquid crystal projector 1 is regularly inspected. In the above, the four air guides 61A, 61B, 61C, 61D, the filter holder 44, and / or the air duct 54 are removed from the optical unit case 4, and the light valve unit 24 inside the air cooling space 41 is air blown. Since it is possible to easily clean the liquid crystal projector 1 by using the above method, the maintainability of the liquid crystal projector 1 can be improved.

(4) Description of Adhesion Structure of Dust and the Like in Light Valve Unit Air Cooling Device Next, the adhesion structure of dust and the like in the light valve unit air cooling device 40 will be described with reference to FIGS. 7 to 15. . The adhered structure of the dust or the like cannot be removed by an intake filter (not shown) of the liquid crystal projector 1 and is a fine dust (dust) of about 10 to 50 μm.
The cooling air flow region between the sirocco fan 47, which is the cooling fan 27, and the inside of the air cooling space 41 is provided with the adhering portion 63 of dust or the like adhering to nicotine, tar, etc. contained in the DS or cigarette smoke. Inside the duct joint 56, and inside the three sets of air passages 55R, 55G, 55B of the air duct 54 (at the lower surface of the light valve unit mounting portion 42, the air passage 55
It also includes a surface facing R, 55G, 55B. ), The four air guides 61A, 61B, 61 in the air cooling space 41.
Any one or a plurality of locations, such as an inner vertical surface facing the light valve unit 24 of C or 61D, a lower surface of the filter holder 44, or an appropriate location on the surface of the light valve unit holder (not shown), or all locations. It was attached to.

Then, the dust-adhering portion 63 is
It is composed of an adhesive material 64 such as a double-sided tape or an adhesive material such as an adhesive paint, and the adhering portion 63 of these dusts or the like is detachable duct joint 56, detachable air duct 54, detachable Four ventilation guides 61
A, 61B, 61C, 61D, a removable filter holder 44, and a removable light valve unit holder are replaceable.

According to the structure for adhering dust or the like configured as described above, as described above, the sirocco fan 47 is actuated to draw in the cooling air CW which is the outside air, and the inside of the duct joint 56 and the blower duct 54. Three sets of ventilation passages 55
Three sets of cooling air outlets 43 through R, 55G, 55B
R, 43G, 43B are blown upward to the lower part in the air-cooling space 41, and three sets of incident side polarization plates 18R, 18G, 18B of the light valve unit 24 and the light valve 1 are provided.
9R, 19G, 19B and exit side polarizing plates 20R, 20
When the surfaces of G and 20B are forcibly air-cooled and the cooling air CW is discharged from the three cooling air discharge ports 60R, 60G, and 60B above the optical unit case 4, the cooling air CW is mixed and sucked into the cooling air CW. Adhesion of nicotine, tar, etc. contained in the smoke of the cigarette inhaled together with the fine dust DS of about 10 to 50 μm and the cooling air CW to the adhesion portion 63 of the dust etc. attached in the cooling air flow region It can be separated from the cooling air CW by adhering (adhering) to the material 64 having.

Therefore, it is possible to prevent the fine dust DS, nicotine, tar, etc. contained in the smoke of cigarettes from scattering in the air-cooling space 41, and the fine dust DS, nicotine, tar scattered Three sets of incident side polarization plates 18R, 18G, 18B of the light valve unit 24, light valves 19R, 19G, 19B and emission side polarization plate 20R,
Three entrance surfaces 2 of 20G, 20B and cross prism 21
It can be attached to 1R, 21G, 21B, etc. Then, it is possible to prevent the adverse effects such as the color disorder of the projected image caused by the adhesion of the fine dust DS and the adverse effects such as the white balance collapse of the projected image caused by the adhesion of nicotine and tar to turn yellow, and the like. The image quality of the image can be significantly improved.

Moreover, the duct joint 5 which is an attachment point of the dust-adhering portion (adhesive material 64) 63.
6, blower duct 54, four blower guides 61A, 61
Since the B, 61C, 61D and the light valve unit holder are configured to be detachable from the optical unit case 4, when the liquid crystal projector 1 is used for a certain period of time (adhesiveness) Material 6
4) When a certain amount of fine dust DS, nicotine, or tar adheres to and accumulates on 63, these duct joint 56, blower duct 54, and four blower guides 61A, 61B, 61
By removing the C, 61D and the light valve unit holder from the optical unit case 4, it is possible to easily perform the cleaning for removing the fine dust DS, nicotine, and tar adhering to and depositing on them. Therefore, maintenance of the liquid crystal projector 1 is easy.

Since the adhesion portion 63 for the dust or the like is made of the adhesive material 64 such as the double-sided tape or the adhesive material 64 such as the adhesive paint, the fine dust DS, nicotine, and tar are removed on both sides. It can be easily cleaned by replacing the tape or repainting the adhesive paint. Furthermore, if necessary, a duct joint 56, a blower duct 54, four blower guides 61A, 61B, 61C, 61D, which are removable parts, and a filter holder 4
You can also perform cleaning (maintenance) by replacing parts such as 4 and light valve unit holder. Regarding the attachment structure of dust or the like in the light valve unit air cooling device 40, the four air guides 61A, 61B,
61C, 61D, etc. are not always necessary.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made based on the technical idea of the present invention.

[0058]

The projection type display device of the present invention configured as described above can achieve the following effects.

According to the first aspect, the cooling air blown upward from the three cooling air outlets at the lower part of the air-cooling space is provided by the vertical air guides provided at the four corners of the air-cooling space. By guiding the cooling air upwardly along the surfaces of the three sets of the entrance side polarizing plate, the light valve and the exit side polarizing plate by guiding it upward, the cooling wind is formed at the filter holder at three places. Since it is possible to smoothly discharge the cooling air to the upper side of the optical unit case from the three cooling air discharge ports arranged directly above, it is possible to prevent turbulent flow of the cooling air in the air cooling space, Prevents adhesion of fine dust to necessary optical components such as the incident side polarization plate, light valve, emission side polarization plate and cross prism, which may occur due to the turbulent flow of the cooling air, and thus the projected image. Possible to prevent an adverse effect of disturbance or the like of the color produced. Therefore, it is possible to realize a high quality projection display device capable of projecting a high quality projected image.

According to the first aspect of the present invention, the cooling air blown upward from the three cooling air outlets in the lower part of the air-cooling space portion is guided by the vertical air guides provided at the four corners of the air-cooling space portion. By guiding the cooling air upwardly along the surfaces of the three sets of the entrance side polarizing plate, the light valve and the exit side polarizing plate by guiding it upward, the cooling wind is formed at the filter holder at three places. Since it can be smoothly discharged to the upper side of the optical unit case from the three cooling air outlets located directly above the fine dust particles, it is difficult for the fine dust to adhere to the dust drop prevention filter and accumulate, and inside the air cooling space. The blowing efficiency of the cooling air can be significantly improved. Therefore, it is possible to remarkably improve the cooling efficiency of the heat-generating components such as the incident-side polarization plate, the light valve, and the emission-side polarization plate, and it is possible to surely keep them below the guaranteed temperature limit. The device can be realized.

According to a second aspect of the invention, the four air guides are formed integrally with or detachably from the optical unit case.
The filter holder that holds the dust drop prevention filter is placed on the top of the optical unit case in a removable manner, and the four air guides are formed integrally with the filter holder, so they are easy to manufacture and assemble. The manufacturing cost can be reduced. In addition, when performing periodic inspections of the projection type display device, remove the four air guides and the filter holder from the optical unit case, and easily use the light valve unit and the cross prism inside the air-cooling space by air blow etc. Since it can be cleaned, it is possible to improve the maintainability of the projection display device.

[Brief description of drawings]

FIG. 1 is a perspective view showing an entire liquid crystal projector to which the present invention is applied as seen through.

FIG. 2 is a perspective view showing an air intake / exhaust port of the liquid crystal projector as seen through.

FIG. 3 is a plan view mainly showing an optical unit of the liquid crystal projector as seen through.

FIG. 4 is a plan view transparently showing the arrangement of a cooling fan and a blower duct with respect to mainly the optical unit of the liquid crystal projector.

5 is a partially cutaway front view taken along the line AA of FIG.

FIG. 6 is an enlarged plan view showing a light valve unit and a cross unit portion in the optical unit of the above liquid crystal projector.

FIG. 7 is a B- of FIG. 6 that also illustrates an adhesion part of dust or the like.
It is a partially notched side view in the direction of arrow B.

FIG. 8 is a C- of FIG. 6 that also illustrates an adhesion part of dust or the like.
It is a partially cutaway side view taken along the arrow C.

FIG. 9 is an exploded perspective view showing three cooling air outlets, a cooling fan, and a ventilation duct of the above liquid crystal projector.

FIG. 10 is an exploded perspective view showing the light valve unit, the filter holder and the four air guides in the light valve unit air cooling device of the liquid crystal projector as seen through.

FIG. 11 is a perspective view showing a modified example of a filter holder and four blower guides in a light valve unit air-cooling device of the above liquid crystal projector in a see-through manner.

FIG. 12 is a partially cutaway plan view showing, in an enlarged manner, four blower guides and an attachment structure of dust and the like in the light valve unit air-cooling device of the liquid crystal projector.

13 is a partially cutaway rear view taken along the line DD of FIG.

FIG. 14 is a partially cutaway side view taken along the line EE of FIG.

FIG. 15 is a perspective view illustrating an attachment structure of dust and the like in the air guide of the liquid crystal projector.

FIG. 16 is an enlarged plan view illustrating a turbulent flow of cooling air in an air-cooling space in which a light valve unit is housed and a problem thereof in a conventional liquid crystal projector.

FIG. 17 is a partially cutaway side view taken along the line FF of FIG.

FIG. 18 is a partially cutaway side view taken along the line GG in FIG.

[Explanation of symbols]

1 is a liquid crystal projector which is a projection type display device, 2 is an outer casing, 4 is an optical unit case, 5 is a power source lamp which is a light source unit, 18R, 18G and 18B are incident side polarization plates, 19
R, 19G, 19B are light valves, 20R, 20G,
20B is an exit side polarization plate, 21 is a cross prism, 24 is a light valve unit, 27 is a cooling fan, 40 is a light valve unit air cooling device, 41 is an air cooling space portion, 4
1a is the four corners of the air-cooling space, 42 is the light valve unit mounting portion, and 43R, 43G and 43B are 3
Cooling air outlets at locations, 44 is a filter holder, 45 is a dust fall prevention filter, 60R, 60G and 60B are cooling air outlets at three locations, and 61A, 61B, 61C and 61D are air guides.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akito Yajima             6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Soni             -Inside the corporation F term (reference) 2H088 EA12 EA14 EA68 HA10 HA13                       HA18 HA23 HA28 MA01 MA20                 5C058 AA06 AB06 BA35 EA01 EA02                       EA26 EA52

Claims (3)

[Claims] 1. Lights in the red, green, and blue wavelength bands of the light emitted from the light source unit are housed at three locations around a cross prism in an air cooling space formed in an optical unit case. A light valve unit including three sets of an incident side polarization plate, a light valve and an emission side polarization plate, which are respectively modulated to obtain images of three colors of red, green and blue; and the cross prism obtained by the light valve unit. And a projection lens for projecting the red, green, and blue images that have been combined in a superimposed manner, and the three sets of the incident side polarization plate, the light valve, and the emission side polarization of the light valve unit at the bottom of the space for air cooling. Cooling air is blown upward from three cooling air outlets at positions corresponding to the lower part of the plate to cool these three sets of incident side polarizing plate, light valve and incident side polarizing plate, respectively. In a projection type display device including a cooling fan for cooling, a filter holder having a dust fall prevention filter mounted on an upper portion of the air cooling space of the optical unit case, the cooling air outlets at the three positions. And three cooling air discharge ports formed at three positions corresponding to the upper part of the air cooling space for discharging the cooling air rising in the air cooling space above the optical unit case, and four corners in the air cooling space. The cooling air blown upward from the three cooling air outlets into the air-cooling space along the surfaces of the three sets of the incident side polarization plate, the light valve and the emission side polarization plate. The projection-type display device is provided with four air-blowing guides that are guided upward toward the above-mentioned three cooling-air discharge ports immediately above. 2. The projection type display device according to claim 1, wherein the four air guides are formed integrally with or detachably from the optical unit case. 3. The filter holder is detachably mounted on an upper part of the optical unit case, and the four air guides are integrally formed on a lower part of the filter holder. The projection display device described.