JP2003241316A - Projection type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a pressure drop of cooling air from the cooling air blowoff port of a cooling fan to three sets of cooling air blowoff ports opened at the bottom of a space for air-cooling a light valve unit. <P>SOLUTION: In a liquid crystal projector, cooling air blowoff parts 78, 79 and 80 formed in the housings 72 and 73 of two sirocco fans 70 and 71 and in the vicinity of rotary blades 76 and 77 are directly connected to cooling air blowoff ports 43R, 43G and 43B at three locations of the lower part of the light valve unit. The cooling air blown from the cooling air blowoff parts 78, 79 and 80 is directly blown into the cooling air blowoff ports 43R, 43G and 43B at three locations of the lower part of the light valve unit not through a fan duct. <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. 22 to 25, 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, 11B and the exit side polarizing plate 116R,
It is equipped with 116G and 116B. 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 116.
B 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 111 is vertically inserted into the center of the air-cooling space 118 together with the cross prism 112 by a light valve unit holder made of sheet metal or the like (not shown), and a horizontal horizontal light valve is mounted on the bottom. The cross prism 112 is mounted on the part 119 and the cross prism 112 is a projection lens 113.
Is located on the optical axis of. It should be noted that the filter holder 1 has a substantially frame-shaped filter holder 120 that is horizontally attached to the center of the filter holder 120 so as to cover the central upper portion of the air-cooling space 118 with a dust-falling filter 121 having air permeability.
20 is horizontally mounted on the top of the optical unit case 110.

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, as in the prior art, the cooling air CW blown out from the sirocco fan 123 is passed through the three duct air passages 127 of the duct joint 128 and the air duct 126 to form three sets of cooling air outlets 122.
The structure that blows upward from R, 122G, 122B to the lower portion of the air-cooling space 118 has a long air blowing path from the sirocco fan 123 to the three sets of cooling air outlets 122R, 122G, 122B, and in the air blowing duct 126. Of 3
The cooling air C blown out from the sirocco fan 123 because the curved shape of the air flow passage 127 of the system becomes the air flow resistance.
W has three sets of cooling air outlets 122R, 122G, 122B
In the meantime, a significant pressure loss of the cooling air is caused. And three sets of cooling air outlets 122R, 122G, 122
If the pressure of the cooling air CW blown from B to the air-cooling space 118 is low, three sets of incident side polarization plates 114R, 114G, 114B, light valves 115R, 115G, 115B and emission side polarization plates of the light valve unit 111 are provided. 1
The cooling efficiency of 16R, 116G, and 116B becomes low, and it becomes difficult to keep these below the guaranteed temperature limit.

Therefore, in the conventional liquid crystal projector,
It was necessary to use a large-sized and large-capacity sirocco fan 123 or to increase the rotation speed of the sirocco fan 123 to increase the static pressure of the cooling air CW blown out. However, the increase in size of the sirocco fan 123 hinders the reduction in size and weight of the liquid crystal projector, and if the number of rotations of the sirocco fan 123 is increased, a secondary obstacle that large noise (fan noise) is generated may occur. There was a problem to say.

The present invention has been made to solve the above problems, and three sets of cooling air outlets are provided from the cooling air outlet of the cooling fan to the bottom of the light valve unit air cooling space. It is an object of the present invention to provide a projection type display device capable of significantly reducing the pressure loss of the cooling air during the period.

[0009]

In a projection type display device of the present invention for achieving the above object, a cooling air blow-out portion formed in the vicinity of a rotary blade in a housing of a cooling fan is air-cooled. The light valve unit housed in the space is directly connected to the three cooling air outlets at the bottom of the light valve unit without using a ventilation duct.

In the projection type display device of the present invention configured as described above, in the housing of the cooling fan, the cooling air blow-out portion formed in the vicinity of the rotating blades is provided at three locations below the light valve unit. By directly connecting to the cooling air outlets and removing the air ducts between these cooling air outlets and the three cooling air outlets, the cooling air blown out from the cooling air outlets of the cooling fan is written. It is possible to directly blow out to the three cooling air outlets at the bottom of the valve unit.

[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 entire liquid crystal projector (FIGS. 1 to 6) (2) ... Explanation of light valve unit air cooling device (FIGS. 6 to 13) (3) ... Explanation (Figs. 14-21)

(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 lamp 5, which is a lamp unit constituting the light source section, has a discharge tube 5a mounted concentrically with a base 5c at the center of a reflector 5b having a substantially conical shape. The emission side is covered with a storm glass 5dd. Further, the fly-eye lenses 6 and 7 arranged at intervals are configured to divide the light emitted from the power source lamp 5 and having a non-uniform luminance distribution into a large number of luminous fluxes, so that the light valves 19R, 19G and 19B.
It has a function of making the luminance distribution of the light illuminating the entire surface of the device uniform. Then, the fly-eye lens 6 on the incident side is brought close to the power lamp 5 side, and the fly-eye lens 7 on the exit side is provided.
A PS conversion element 8 is arranged in close proximity to the. This P
The S conversion element 8 is composed of a polarizing 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. There is.

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. Inside the outer casing 2, a light valve unit air-cooling device 40, which will be described later, is arranged below the light valve unit 24, and two exhaust fans 28 are provided in front of the power lamp 5 and in front of the power board 26. , 29 are arranged. An exhaust fan 30 is also arranged on the left side surface of the optical unit case 4 in the vicinity of the fly-eye lens 7 and the PS conversion element 8. And
Intake ports 31 and 32 are formed on the side surface 2b of the outer casing 2 and the back surface 2d of the outer casing 2, and the front face 2a of the outer casing 2 is located in front of the two exhaust fans 28 and 29. The exhaust ports 33 and 34 are formed.

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 through the output side polarization plates 20R, 20G, and 20B of B, and these three image lights of R, G, and B are three incident surfaces 21R of the cross prism 21, 21G and 21B are respectively incident from three optical axes P4, P5 and P6.

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) Description of Light Valve Unit Air Cooling Device Next, the light valve unit air cooling device 40 will be described with reference to FIGS. 6 to 13. First, as shown in FIGS. 6 to 11, the light valve unit air-cooling device 40 has a substantially rectangular shape that is cut out in a substantially U-shape at the position behind the projection lens 25 and at the front side position of the optical unit case 4. Thus, it has a space 41 for air cooling 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 first and second two sirocco fans 70 and 71, which constitute two cooling fans, are provided below the light valve unit mounting portion 42, which is a position corresponding to the lower portion of the light valve unit 24. It is removable and is installed horizontally. At this time, the first and second sirocco fans 70 and 71 are rotated integrally with rotors 74 and 75 of a motor (not shown) at eccentric positions of housings 72 and 73 which are substantially spirally shaped. Rotating blades 76 and 77 are arranged. The first sirocco fan 70 is provided with two cooling air blowing portions 78, 79 on the cooling air blowing direction side by the rotating blades 76, and the two cooling air blowing portions 78, 79 are provided in the light valve. Directly connected to the lower parts of the cooling air outlets 43R and 43G, which are two of the three cooling air outlets 43R, 43G, and 43B formed in the unit mounting portion 42 (directly without passing through a ventilation duct). Connected)
Has been done.

Further, the second sirocco fan 71 is provided with one cooling air blowing portion 80 on the side where the cooling air is blown by the rotary blades 76, and this one cooling air blowing portion 80 is provided in the light valve unit. It is directly connected to the lower part of the remaining cooling air outlet 43B formed in the mounting portion 42 (that is, directly connected without the air duct). In addition, intake ports 81 and 82 are opened directly below the lower surfaces of the housings 72 and 73 of the first and second sirocco fans 70 and 71, respectively.

The housings 72, 73 of the first and second sirocco fans 70, 71 can be constructed as follows, for example. That is, the light valve unit mounting portion 42 is also used as a common component for the upper cover, and the light valve unit mounting portion 42 is molded with a synthetic resin or the like to provide two intake ports 81,
Lower cover 83 as a common part with 82 open
And an intermediate cover 84 constituting the outer peripheral portions of the respective rotary vanes 76, 77 and the outer peripheral portions of the cooling air blowing portions 78, 79,
And 85. And two rotary blades 7
6, 77 are rotatably mounted on the lower surface of the light valve unit mounting portion 42, and two intermediate covers 84, 85 and a lower cover 83 are removably mounted on the lower surface of the light valve unit mounting portion 42 from below, thus providing two housings. 7
2, 73 can be configured.

At this time, it is possible to integrally form the two intermediate covers 84 and 85 on the upper surface of the lower cover 83.
The upper and lower ends of the two intermediate covers 84 and 85 are detachably fitted to a pair of upper and lower fitting portions (fitting grooves) 86 formed on the lower surface of the light valve unit mounting portion 42 and the upper surface of the lower cover 83. The two intermediate covers 84 and 85 are configured to be attachable to and detachable from both the light valve unit mounting portion 42 and the lower cover 83.
The sirocco fans 70 and 71 can be easily disassembled, and maintainability is improved. Then, one drive circuit 87 that is commonly driven by the first and second sirocco fans 70 and 71 is provided on the upper surface or the lower surface of the light valve unit mounting portion 42.
Is attached.

In the light valve unit air-cooling device 40, when the liquid crystal projector 1 is driven, the first and second sirocco fans 70 and 71 are simultaneously operated to rotate integrally with the rotors 74 and 75. Rotary vane 7
The cooling air CW, which is the outside air, is sucked from the intake port 31 of the outer casing 2 through the intake ports 81 and 82 by 6, 77. Then, the cooling air CW is pressurized in the housings 72, 73 by the rotary vanes 76, 77 to make the housings 72, 7
Three sets of cooling air outlets 43R, 43G, 43B are blown upward from the three cooling air outlets 78, 79, 80 to the lower part of the air-cooling space 41 from these three sets of cooling air outlets 43R, 43G, 43B.

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.

Most of the cooling air CW rising in the air cooling space 41 is the outer peripheral portion of the filter holder 44 holding the dust drop prevention filter 45, and three cooling air outlets 43R, 43G are provided. Cooling air discharge ports 60R, 60 formed at three positions directly above 43B.
Above the optical unit case 4 from G and 60B, the outer casing 2
Is smoothly discharged into the inside of the cooling air CW, and a part of the cooling air CW passes through the dust drop prevention filter 45 and is discharged upward.

When the liquid crystal projector 1 is driven, the exhaust fans 28, 29 and the intake fan 30 are operated simultaneously with the first and second sirocco fans 70, 71. The cooling air, which is the outside air, is introduced into the intake port 3 shown in FIG.
1 is sucked into the outer casing 2 and the cooling fan is blown into the light emission side of the power supply lamp 5 in the optical unit case 4 by the intake fan 30, while the high temperature heat generated by the power supply lamp 5 is exhausted by the exhaust fan 18 The exhaust port 33 shown in FIG.
From the front of the outer casing 2 to the power lamp 5
Forced air cooling. At the same time, the power supply board 26
2 shows the heat generated by heat-generating components such as a condenser, an IC, and a power transformer mounted on the housing, and hot air emitted from the inside of the air cooling space 41 to the inside of the outer casing 2 above the optical unit case 4. The air is exhausted from the exhaust port 34 to the front of the outer casing 2, so that the condenser of the power supply board 26 and the I
C, the heat-generating components such as the power transformer are forcibly air-cooled, and the heat-generating components such as the power lamp 5 and the power substrate 26 are kept below the guaranteed temperature limit.

By the way, according to the light valve unit air-cooling device 40, the first and second sirocco fans 70,
71 supplies cooling air CW pressurized by the rotary vanes 76 and 77, respectively, to three sets of cooling air outlets 43R, 43G, 4 from the cooling air outlets 78, 79 of these housings 72, 73.
Since it can be blown directly to 3B without passing through a ventilation duct, the ventilation resistance is very small and the cooling air CW
The pressure loss of can be significantly reduced.

Therefore, the first and second sirocco fans 7
0, 71 are three sets of cooling air outlets 43R, 43G, 43B
Since the high-pressure cooling air CW can be vigorously blown out to the lower part of the air-cooling space 41, the air-blowing efficiency of the cooling air CW in the air-cooling space 41 is significantly improved, and three sets of the light valve unit 24 are provided. Incident side polarization plates 18R, 18G,
The cooling efficiency of 18B, the light valves 19R, 19G, and 19B and the exit side polarizing plates 20R, 20G, and 20B is improved, and these can be safely kept below the limit guarantee temperature.

The first sirocco fan 70 blows the cooling air CW into the two cooling air outlets 43R and 43G, whereas the second sirocco fan 71 blows the cooling air CW into only one cooling air outlet 43B. Therefore, the pressure of the cooling air CW blown upward from the cooling air outlet 43B into the air-cooling space 41 is increased so that the temperature tends to be particularly high and the light valve 19B and the entrance / exit side polarization plates 18B, 2
The cooling efficiency of 0B can be increased.

On the other hand, in the conventional light valve unit air-cooling device described with reference to FIGS. 22 to 25, the operation of the sirocco fan 123 causes its cooling air outlet 12
The cooling air CW, which is the outside air sucked from 4, is blown into the air blowing duct 126 from the cooling air outlet 125 via the duct joint 128, and the three cooling air CWs are blown in the three air blowing passages 127 in the air blowing duct 126. It is branched into the system and blown upward from the three sets of cooling air outlets 121R, 121G, 121B 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, 114G, 1 of the light valve unit 111.
14B, the light valves 115R, 115G, 115B and the emission side polarization plates 116R, 116G, 116B are raised to cool these surfaces. Then, the cooling air C rising in the air cooling space 118
The W is configured to pass through the dust drop prevention filter 121 on the upper portion and be discharged to the upper portion of the optical unit case 110.

Therefore, in the conventional air cooling system for the light valve unit, the air blowing path from the sirocco fan 123 to the three sets of cooling air outlets 122R, 122G, 122B is long, and the three air blowing passages in the air blowing duct 126 are provided. 1
The curved shape of 27, etc. acts as a ventilation resistance, and the sirocco fan 1
The cooling air CW blown from the air conditioner 23 causes a significant pressure loss of the cooling air while reaching the three sets of cooling air outlets 122R, 122G, 122B, and the three pairs of incident side polarization plates 114R, 114G, 114B of the light valve unit 111. , The cooling efficiency of the light valves 115R, 115G, 115B and the exit side polarizing plates 116R, 116G, 116B becomes low,
There has been a problem that it is difficult to keep these below the guaranteed temperature limit. However, such a problem of the conventional light valve unit air cooling device can be solved by the light valve unit air cooling device 40 of the liquid crystal projector 1 of the present invention described with reference to FIGS. 6 to 13.

By the way, in the liquid crystal projector 1, it cannot be removed by an intake filter (not shown), and it is contained in the fine dust DS of about 10 to 50 μm and the smoke of the cigarette which is sucked by being mixed with the cooling air CW. Nicotine,
Tar or the like is blown into the space 41 for air cooling, and three sets of incident side polarization plates 18R, 18G, 18B and the light valve 1 are provided.
9R, 19G, 19B and exit side polarizing plates 20R, 20
The surface of G, 20B and the incident surface 21 of the cross prism 21
When it adheres to R, 21G, 21B, etc., it causes adverse effects such as color disorder in the projected image, white balance loss, and yellowing.

Therefore, as shown in FIGS. 9 to 10, the housing 7 of the first and second sirocco fans 70 and 71 is used.
The inner surfaces 84a of the intermediate covers 84, 85 within the 2, 73,
85a, the lower surface of the light valve unit mounting portion 42 or the upper surface 83a of the lower cover 83, inside the air passages 88 such as inside the intermediate covers 84 and 85, the adhesive material 89 such as double-sided tape or the adhesive material 89 such as adhesive paint. If attached, fine dust DS and nicotine mixed in the cooling air CW sucked by the first and second sirocco fans 70, 71,
Tar or the like can be attached to the adhesive material 89 in the housings 72 and 73 of the first and second sirocco fans 70 and 71 to be separated from the cooling air CW.

Therefore, these fine dust particles DS, nicotine, tar, etc. are blown into the air cooling space 41, and 3
A pair of incident side polarization plates 18R, 18G, 18B, light valves 19R, 19G, 19B and emission side polarization plates 20R, 2
The surface of 0G, 20B and the incident surface 21 of the cross prism 21
It can be prevented from being attached to the surface of R, 21G, 21B, and the like, and it is possible to prevent adverse effects such as color disorder of the projected image and yellowing due to collapse of white balance.

At this time, the first and second sirocco fans 7
Since the housings 72 and 73 of Nos. 0 and 71 are configured to be disassembled, the housings 72 and 73 are disassembled every time the liquid crystal projector 1 is used for a certain time (period), and the adhesive material 89 is attached. The accumulated fine dust DS, nicotine, tar, etc. can be easily cleaned, or the housings 72, 73 are used as required.
The cleaning can be easily performed by replacing the parts of the lower cover 83 and the intermediate covers 84 and 85, and the maintainability is improved.

Next, FIGS. 12 and 13 show a modified example of the light valve unit air-cooling device 40.
In this modification, one special sirocco fan 90 blows the cooling air CW from the three cooling air outlets 43R, 43G, 43B to the lower part of the air cooling space 41. That is, this one special sirocco fan 90 is horizontally attached to the lower portion of the light valve unit mounting portion 42, and has a small-diameter and circular intake port 92 at the central portion of the lower surface and the central portion of the upper surface of the flat housing 91. And a large-diameter annular exhaust port 93 are opened concentrically.

An intake / exhaust passage 94 is formed between the intake port 92 and the exhaust port 93 in the housing 91 and is bent in a substantially crank shape with respect to the vertical axial direction X. In the exhaust passage 94, a rotary blade 96 that is rotated integrally with a rotor 95 of a motor (not shown) is concentrically arranged, and the rotary blade 96 has a large number of radial sirocco fan blades 96a. is doing. Then, on the outer circumference of the rotary blade 96 in the intake / exhaust passage 94, a large number of exhaust grooves having a spiral inclination with respect to the axial direction X (see FIG. 17).
(The same as the exhaust groove 107 of No. 97) is formed. The annular exhaust port 93 is formed in one cooling air outlet of the housing 91, and the exhaust port 93 is directly connected to the lower portions of the three cooling air outlets 43R, 43G, 43B.

According to the special sirocco fan 90 having the above-described structure, when a large number of sirocco fan blades 96a having a radial shape of the rotary blades 96 are rotated integrally with the rotor 95, the cooling air, which is the outside air, is transferred to the outer casing. After being sucked from the intake port 92 into the intake / exhaust passage 94 in the housing 91 through the intake port 31 of the side surface 2b in the x1 direction parallel to the axial direction X,
A large number of radial sirocco fan blades 96a change the direction by 90 ° to a direction x2 orthogonal to the axial direction X and discharge the gas. Further, a large number of exhaust grooves 97 on the outer circumference again cause a 90 ° direction in the x2 direction parallel to the axial direction X. The converted cooling air outlets 43R, 43 from the annular exhaust port 93
It will be blown upward into the air cooling space 41 through G and 43B.

Then, as described above, three sets of incident side polarization plates 18 in the air-cooling space 41 are generated by the cooling air.
R, 18G, 18B, light valves 19R, 19G, 1
The surfaces of 9B and the exit side polarization plates 20R, 20G and 20B are forcibly air-cooled. In this way, if it is configured so that the cooling air can be blown directly into the air cooling space 41 by the single flat special sirocco fan 90,
Three sets of incident side polarization plates 18R, 18G and 18B, light valves 19R, 19G and 19B and emission side polarization plates 20R,
In addition to the high cooling efficiency of 20G and 20B, it is possible to realize cost reduction and downsizing (thinning) and weight reduction by reducing the number of parts and the number of assembly steps of the liquid crystal projector 1.

(3) Description of Power Lamp Air Cooling Device Next, referring to FIGS. 14 to 19, the power lamp air cooling device 9 will be described.
9 will be described. First, FIG. 14 shows an intake / exhaust system of the power lamp air-cooling device 99. By operating the exhaust fan 28, the cooling air, which is the outside air, is changed to FIG.
Is sucked into the outer casing 2 through the intake port 32 shown in
At the end 4a of the optical unit case 4, the air is sucked into the outer periphery of the power lamp 5 in the optical unit case 4 from the intake ports 35 opened at positions corresponding to both sides of the power lamp 5. Then, the high-temperature heat generated by lighting the discharge tube 5a of the power lamp 5 is sucked by the exhaust fan 28, and the high-temperature heat shown in FIG.
It is configured to be discharged to the outside (front) of the outer casing 2 from the exhaust port 33 shown in FIG.

Next, as shown in FIGS. 15 to 17, a special sirocco fan 100 is used as the exhaust fan 28. The special sirocco fan 100 accommodates the power lamp 5 of the optical unit case 4. End 4a
It is vertically arranged between the exhaust port 33 of the outer casing 2 and the opening 4b. In this special sirocco fan 100, a small and circular intake port 102 is formed in the center of the power supply lamp 5 side of a square and flat housing 101, and a large diameter and circular shape is formed on the exhaust port 33 side of the housing 101. An annular exhaust port 103 is formed concentrically with the intake port 102.

Then, the intake port 10 in the housing 101
2 and the exhaust port 103, an intake / exhaust passage 104 that is bent in a substantially crank shape with respect to the vertical axial direction X is formed, and in the intake / exhaust passage 104, a motor (not shown) is formed. Rotating blade 1 that is rotated integrally with rotor 105
06 are arranged concentrically, and the rotary blades 106 thereof have a large number of radial sirocco fan blades 106a. Then, the rotary vanes 106 in the intake / exhaust passage 104
A large number of exhaust grooves 107 having a spiral shape or the like with respect to the axial direction X are formed on the outer circumference of the.

The special sirocco fan 100 of the power lamp air cooling device 99 is configured as described above, and when the liquid crystal projector 1 is driven, the special sirocco fan 1 is
When the rotating blades 106 of No. 00 are rotated together with the rotor 105, a large number of radial sirocco fan blades 106a are formed.
Causes a high static pressure. Then, in the power supply lamp 5, hot air HW, which is high-temperature heat generated by lighting of the discharge tube 5a, passes through the opening 4b of the optical unit case 4 from the circular intake port 102 into the intake / exhaust passage 104 in the housing 101 in the axial direction. After being sucked in a direction x1 parallel to X, a large number of sirocco fan blades 106 are formed in a radial pattern.
a is converted by 90 ° into a direction x2 orthogonal to the axial direction X and emitted, and further, a large number of exhaust grooves 9 in the outer peripheral portion are emitted.
By 7 again, the direction is changed by 90 ° in the x2 direction parallel to the axial direction X, and is discharged to the front of the outer casing 2 through the exhaust port 103 having an annular shape and a large opening area through the exhaust port 33.

As described above, in short, the special sirocco fan 100 heats the heat generated by the power supply lamp 5 and the like in the intake / exhaust passages 104 bent in a substantially crank shape by x1, x2,
Efficient discharge can be performed while changing the direction in the crank direction in the x3 direction. Moreover, even if the light leaking from the power supply lamp 5 enters the intake port 102 that is opened in the axial direction X of the special sirocco fan 100, this light is bent into a substantially crank shape. It is possible to prevent the light from being blocked inside 104 and leaking from the exhaust port 103 to the front of the exhaust port 33 of the outer casing 2 in advance.

Therefore, the special sirocco fan 100 is configured as a sirocco fan having a light leakage prevention function by the light leakage prevention louver, and the light leakage prevention louver can be eliminated, so that the number of components of the liquid crystal projector 1 and It is possible to reduce costs by reducing the number of assembly steps and to reduce size and weight. Moreover, this special sirocco fan 100 can increase the static pressure as compared with an axial flow fan as well as an ordinary (general) sirocco fan, and the opening area of the annular exhaust port 103 can be increased. Can be made as large as an axial fan, and the heat generation area can be dispersed and expanded. Therefore, the rotational speed of the rotary blade 106 can be increased as in a conventional axial fan to increase the exhaust air volume. You don't have to. That is, even if the number of rotations of the rotary blades 106 is reduced, the required exhaust amount can be sufficiently secured, and the heat exhaust of the power supply lamp 5 can be performed with low noise and high efficiency. It is possible to realize high safety that can be stably maintained below the limited guarantee temperature.

That is, by using this special sirocco fan 100, the light leaking from the power lamp 131 can be prevented from leaking through a large number of diagonals of the light leakage preventing louver 133 as in the conventional liquid crystal projector shown in FIGS. While blocking the cut portion 133a, the high-temperature hot air HW generated by the power supply lamp 131 is cut into a large number of diagonal cut portions 1
The outer casing 109 is sucked by the axial fan 134 through 33a.
The light leakage preventing louver 133 is required as in the case of exhausting air forward from the exhaust port 132, which leads to an increase in cost due to an increase in the number of parts and assembling man-hours, or due to a significant air blowing resistance at a large number of diagonal cut portions 133a. The heat exhaust efficiency (cooling efficiency) deteriorates, and the power lamp 131
It is possible to solve the problem that it becomes difficult to keep the temperature below the guaranteed temperature limit. In addition, this special sirocco fan 100
Can also be applied to the exhaust fan 29 for thermally exhausting heat-generating components such as capacitors, ICs, and power transformers mounted on the power supply substrate 26 shown in FIGS. 3 and 4.

Next, FIGS. 18 and 19 show a modified example of the special sirocco fan 100, in which a large number of radial sirocco fan blades 106a of the rotary blade 106 have a tilt component with respect to the axial direction X. 16 and 17 are provided with an inclined or spiral twist.
Of the exhaust grooves 107 on the outer periphery of the intake / exhaust passage 104 shown in FIG.
Is omitted.

According to the modified example of the special sirocco fan 100, a large number of radial sirocco fan blades 1 are provided.
Due to the rotation of 06a, a large number of sirocco fan blades 1
Hot air H in the x2 direction, which is outward due to the radial shape of 06a
Extruding action of W and its many sirocco fan blades 1
After the hot air HW is sucked from the intake port 102 of the housing 101 into the intake / exhaust passage 104 from the x1 direction by the combined effect of the inclination of 06a with respect to the axial direction X, the spiral wind twist, and the like, and the hot air pushing action in the x3 direction, The hot air HW can be bent substantially in a crank shape in the x2 direction and the x3 direction and discharged from the exhaust port 103. Therefore, according to the modified example of the special sirocco fan 100,
As shown in FIGS. 16 and 17, there is no need to process a large number of exhaust grooves 107 on the outer periphery of the intake / exhaust passage 104,
Since manufacturing (processing) is easy, cost reduction can be achieved.

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

[0065]

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

According to a first aspect of the present invention, there is provided a cooling fan housing, wherein a cooling air blowing portion formed in the vicinity of the rotary vanes is directly connected to three cooling air blowing outlets at a lower portion of the light valve unit. By removing the air duct between the cooling air outlet and the three cooling air outlets,
The cooling air blown out from the cooling air blowout part of the cooling fan can be directly blown out to the three cooling airflow outlets at the lower part of the light valve unit. The pressure loss of the cooling air between the three sets of cooling air outlets opened at the bottom of the air cooling space can be significantly reduced, and even if the number of rotations of the cooling fan is reduced, the high blowing efficiency is achieved. Got
High cooling efficiency of the light valve unit can be obtained. Therefore, while achieving high safety that the light valve unit can be forcibly air-cooled below the guaranteed temperature limit, low noise of the projection type display device is realized by lowering the rotation speed of the cooling fan, and air blowing is achieved. Cost reduction of projection type display device due to disposal of duct, small size,
Weight reduction can be realized.

According to the second aspect, since the sirocco fan that constitutes the cooling fan is horizontally installed in the lower portion of the light valve unit, the projection type display device can be made thin.

According to the third aspect, two sirocco fans are used, one of which blows cooling air to two of the three cooling air outlets, and the other one of which has three cooling air outlets. Since the cooling air is blown to another one of them, it is possible to set the amount of cooling air to be blown according to the difference in the heat generation amount of the three light valves of the light valve unit and the polarization plate on the entrance / exit side. Therefore, efficient forced air cooling can be performed.

According to the fourth aspect of the present invention, since one driving circuit for driving the two sirocco fans in common is provided, simplification of the structure and space saving can be realized.

According to the fifth aspect of the present invention, one sirocco fan blows the cooling air to the three cooling air outlets at the same time. Therefore, it is possible to reduce the cost and the size and weight by reducing the number of parts and the number of assembling steps. .

[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 mainly showing a light valve unit air-cooling device of the above liquid crystal projector as seen through.

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 air cooling device of the above liquid crystal projector.

7 is a cross-sectional view taken along the line BB of FIG.

FIG. 8 is an enlarged plan view showing a cooling fan portion of the above light valve unit air cooling device.

FIG. 9 is a partially cutaway bottom view of a cooling fan portion of the above light valve unit air cooling device.

FIG. 10 is an exploded perspective view of a cooling fan portion of the above light valve unit air-cooling device as viewed from below.

FIG. 11 is an exploded perspective view of the cooling fan portion of the above light valve unit air cooling device as seen from above.

FIG. 12 is a plan view showing a modified example of the above light valve unit air cooling device.

13 is a cross-sectional view taken along the line CC of FIG.

FIG. 14 is a perspective view showing the power lamp air cooling device of the liquid crystal projector as seen through.

FIG. 15 is a partially cutaway side view of the above power lamp air cooling device.

FIG. 16 is a partially cutaway front view and two partially cutout side views for explaining a special sirocco fan of the above power lamp air cooling device.

FIG. 17 is a perspective view for explaining a large number of spiral exhaust grooves formed on the outer periphery of the rotary blade in the housing of the special sirocco fan of the power lamp air cooling device of the above.

FIG. 18 is a partially cutaway front view and two partially cutout side views for explaining a modified example of the special sirocco fan of the above power lamp air cooling device.

FIG. 19 is a perspective view illustrating a spiral twist of a large number of radial sirocco fan blades of a special sirocco fan of the above power lamp air cooling device.

FIG. 20 is a partially cutaway side view illustrating a power lamp air cooling device of a conventional liquid crystal projector.

21A and 21B are a front view and a partially cut-away side view illustrating an axial fan used in a conventional power lamp air cooling device.

FIG. 22 is a plan view illustrating a light valve unit air cooling device of a conventional liquid crystal projector.

23 is a sectional view taken along the line DD of FIG.

24 is a cross-sectional view taken along the line EE of FIG.

FIG. 25 is an exploded perspective view of a cooling fan and a ventilation duct of a conventional light valve unit air cooling device.

[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
2 is a light valve unit mounting portion, 43R, 43G, 4
3B is three cooling air outlets, 70 and 71 are first and second
Sirocco fan, 72, 73 housing, 74, 7
5 is a rotor, 76 and 77 are rotary blades, 78, 79 and 80
Is a cooling air outlet, 81 and 82 are intake ports, 83 is a lower cover, 84 and 85 are intermediate covers, 87 is one drive circuit,
90 is a special sirocco fan, 91 is a housing, 92 is an intake port, 93 is an exhaust port, 94 is an intake / exhaust passage, 95 is a rotor, 96 is a rotating blade, 96a is a sirocco fan blade, 9
7 is an exhaust groove.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H088 EA14 EA15 HA05 HA13 HA23                       HA24 HA28 MA20                 3L044 AA04 BA06 CA13 CA18 DA01                       FA03 KA04                 5C058 BA23 EA01 EA02 EA11 EA21                       EA26 EA52

Claims (5)

[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 the projection display device including a cooling fan, a cooling air blowout portion formed in the housing of the cooling fan in the vicinity of the rotary vanes is provided at three locations below the light valve unit. A projection type display device characterized in that it is directly connected to the outlet without passing through a ventilation duct. 2. The projection type display according to claim 1, wherein the cooling fan is composed of a sirocco fan, and the sirocco fan is horizontally installed in a lower portion of the light valve unit. apparatus. 3. A first sirocco fan that blows cooling air to two of the three cooling air outlets at the bottom of the light valve, and one of the three cooling air outlets. The projection type display device according to claim 2, wherein the projection type display device is composed of a total of two sirocco fans including a second sirocco fan that blows out cooling air to another one place. 4. The projection type display device according to claim 3, further comprising one drive circuit for commonly driving the first and second sirocco fans. 5. The cooling fan is composed of a single sirocco fan capable of simultaneously sending cooling air to three cooling air outlets in the lower portion of the light valve unit. 2. The projection display device according to item 2.