JP2000147652A - Projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type display device, capable of efficiently cooling an optical modulation device and stably securing image quality over a long period. SOLUTION: An optical modulation device 925, constituted of a projection type display device, is stored inside the hermetically sealed part that consists of a sealing box 80 and a head body 903, and the air inside the hermetically sealed part is circulated by an air circuit passage 90, which is arranged in a cooling flow passage inside the display device on the side of a projection lens 6. Since the air circuit passage 90 is arranged in the cooling flow passage, the air inside as well as the air circuit passage 90 is cooled, enabling the optical modulation device 925 to be cooled efficiently by this air circulation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source, a light modulator for modulating a light beam emitted from the light source in accordance with image information, and a projection lens for enlarging and projecting an image formed by the light modulator. The present invention relates to a projection display device provided with:

[0002]

2. Description of the Related Art Conventionally, a light source, an optical system for modulating a light beam emitted from the light source according to image information to form an optical image, and a projection lens for enlarging and projecting the modulated light beam on a projection surface have been proposed. Are used. The optical system is an illumination optical system that equalizes the in-plane illuminance distribution of the light beam emitted from the light source, a color separation optical system that separates the light beam from this illumination optical system into the three primary colors of red, blue, and green. , And a color synthesizing optical system that synthesizes each color light beam after modulation. The light modulation system includes three light modulation devices that modulate each of the red light beam, the blue light beam, and the green light beam separated by the color separation optical system according to image information.

In such a light modulation device, for example, a light modulation element such as a liquid crystal panel using a polysilicon TFT as a switching element is employed. Since this light modulation device is an important part for forming an optical image according to image information,
If dust, oily smoke, etc. adhere to the surface of the liquid crystal panel or the like, there is a problem that the image quality of the projection display device is deteriorated.
For this reason, it is conceivable to employ a projection display device having a sealing portion for sealing the optical path from the light modulation device to the projection lens. In the case of a projection type display device having such a sealed portion, dust and oily smoke can be prevented from entering from the outside by the sealed portion, so that dust, oily smoke and the like adhere to the liquid crystal panel surface of the light modulation device. In addition, the image quality of the projection display device can be stably ensured for a long period of time, and is suitable as a stationary projection display device such as a ceiling suspension type.

[0004]

However, since a light modulation element such as a liquid crystal panel is weak to heat, as described above,
If the optical path from the light modulation device to the projection lens is sealed by a sealing portion, there is a problem that it is difficult to efficiently cool the light modulation device by introducing cooling air from outside the device. In particular, in recent years of increasing the brightness and reducing the size of the projection display device, it is important to efficiently cool the light modulation device.

An object of the present invention is to provide a light source, a light modulator for modulating a light beam emitted from the light source in accordance with image information, and a projection lens for enlarging and projecting an image formed by the light modulator on a projection surface. In the projection display device having
It is an object of the present invention to provide a projection display device that can efficiently cool a light modulation device and can stably secure image quality for a long time.

[0006]

In order to achieve the above object, a projection display apparatus according to the present invention comprises a light source, a light modulator for modulating a light beam emitted from the light source in accordance with image information, A projection display device comprising: a projection lens for enlarging and projecting an image formed by the light modulation device, wherein a sealing portion for sealing an optical path from the light modulation device to the projection lens, and air in the sealing portion. And an air circulation path for circulating the air. The air circulation path is disposed in a flow path of cooling air formed inside the projection display device.

Here, the sealing portion can be constituted by a box-shaped member for hermetically storing the light modulator therein, and the box-shaped member may be made of a metal such as a magnesium alloy. it can. In addition, the air circulation path can be constituted by, for example, a pipe-shaped member having one end connected to the upper portion of the sealed portion and the other end connected to the lower portion of the sealed portion. In short, the airtightness of the sealed portion is maintained. What is necessary is just to be a structure which can circulate the air in a sealing part upward from below or upward from above. Furthermore, it is preferable to install a forced circulation device such as a fan inside the sealed portion to circulate the air inside. As the forced circulation device, a normal axial flow fan can be employed, but preferably, a centrifugal fan for discharging air taken in by rotation in a tangential direction of rotation is preferable.

According to the present invention, since the air circulation path is disposed in the cooling air flow path formed inside the projection type display device, the air circulation path is cooled while the air circulation path is cooled. The flowing air is also cooled. Then, the air in the cooled air circulation path circulates through the inside of the closed portion, so that the light modulation device can be efficiently cooled.
In addition, since air for cooling the light modulation device is circulated only in the closed portion and the air circulation path, dust and oil smoke do not enter from the outside, and the image quality of the projection display device is stabilized for a long time. Can be secured.

In the above, as the above-mentioned air circulation path, it is preferable to adopt a pipe-shaped member made of metal such as copper or aluminum having good heat conductivity, and the inner diameter thereof is 10 mm to 10 mm.
It is preferably set to 30 mm.

That is, since the pipe-shaped member made of metal such as copper or aluminum has a high heat radiation property, if it is arranged in the cooling air flow path inside the projection display device, the air inside the air circulation path can be more efficiently used. Can be cooled. In addition, when the above-described centrifugal fan is used as the forced circulation device, when the discharge pressure of the centrifugal fan and the flow path length of the air circulation path that is substantially equal to the outlet opening area of the centrifugal fan are considered, Is set to 10 mm to 30 mm, it is possible to sufficiently circulate the air inside the sealed portion with a centrifugal fan.

It is preferable that the above-mentioned air circulation path is detachable from the sealing part, and the air circulation path and the sealing part are connected via a sealing material. Here, as the sealing material, a material made of an elastic body such as rubber can be adopted.

That is, since the sealing portion and the air circulation path are detachable, maintenance of the light modulator and the like inside the sealing portion can be easily performed. Further, since the air circulation path and the sealed portion are connected via the sealing material, it is possible to reliably prevent air leakage inside the sealed portion. further,
Even when the sealing part and the air circulation path are made of different metals, such as a material made of a magnesium alloy and a material of the air circulation path made of aluminum, the two are interposed through a sealing material such as rubber. Since the connection is made, no electrolytic corrosion occurs at the dissimilar metal joining portion, and the hermeticity of the hermetically sealed portion is permanently secured.

Further, it is preferable that the above-mentioned air circulation path is provided with a heat radiation structure for releasing heat inside the circulation path to the outside. As the heat radiating structure, for example, a heat radiating structure including a plurality of heat radiating fins extending along the radial outside of the air circulation path can be adopted. Further, as another example, a linear material having a linear core material and a plurality of heat radiation pieces protruding radially outward of the core material is spirally formed on the outer periphery of the air circulation path. A radiating structure configured by winding can be adopted.

That is, since the air circulation path has such a heat radiation structure, if the air circulation path is arranged in the flow path of the cooling air inside the projection display device, the air inside the air circulation path is cooled. Thus, the cooling can be performed more efficiently.

It is preferable that the above-described air circulation path is disposed on the side of the projection lens.

That is, since the projection lens has an optical adjustment mechanism such as zoom and focus, the projection lens becomes longer by that amount, and a dead space is likely to be generated on the side of the projection lens. Therefore, if the air circulation path is arranged in such a portion, the structure inside the projection display device can be made dense, which is advantageous for miniaturization of the projection display device.

Further, it is preferable that a cooling fan for cooling the inside of the projection type display device is provided near the above-mentioned air circulation path. Here, the cooling fan is not limited to the one dedicated to blowing the cooling air into the air circulation path, and may be a cooling fan provided to cool other parts of the projection display device.

That is, since the cooling fan is provided near the air circulation path, the air circulation path can be more efficiently cooled by forcedly introducing or discharging the cooling air by the cooling fan.

Further, the above-mentioned projection display device accommodates and arranges optical components such as a lens and a mirror, and has an optical component housing disposed adjacent to the sealing portion. When an intake fan that takes in external air is arranged inside the device, a cooling air introduction flow passage that guides cooling air taken in from the intake fan is formed at the boundary between the sealing portion and the optical component housing. Is preferred.

That is, since the cooling air introduction flow path is formed, the entire closed section can be cooled by the cooling air taken in from the intake fan, and the air inside the closed section is cooled together with the air circulation path described above. Cooling can be performed more efficiently, and a rise in the temperature of the light modulation device can be prevented.

Preferably, the above-mentioned cooling air introduction path is formed as a gap formed along a boundary between the sealed portion and the optical component casing, and the size of the gap is set to 1 mm to 10 mm. Is preferred.

That is, if the cooling air introduction flow path is formed in this way, the cooling air introduction flow path can be configured without providing a separate duct or the like, so that the structure inside the projection display device can be simplified. In addition to this, it is possible to maintain the improvement of the cooling efficiency by the cooling air introduction path.

Further, between the above-described boundary portion of the optical component casing along the cooling air introduction flow path and the intake fan,
It is preferable that a cover member is provided so as to surround the cooling air introduction flow path.

That is, since the cover member is provided, it is possible to guide the cooling air from the cooling fan to the cooling air introduction path as necessary and sufficiently, and the cooling efficiency of the sealed portion is further improved.

Further, when the above-mentioned projection type display device is provided on the upper part of the optical component casing and has a drive circuit board for driving the light modulator, the above-mentioned cover member includes the drive circuit board. It is preferable that a cooling air introduction opening for guiding a part of the cooling air is formed in the opening. Here, the size of the cooling air introduction opening can be appropriately set according to the size of the drive circuit board and the heating state when the mounted circuit element is driven.

That is, since the cooling air introduction opening is formed in the cover member, a part of the cooling air from the intake fan can be guided to the drive circuit board for cooling, and the inside of the projection display device can be cooled. It becomes possible to cool the heating part appropriately.

In the case where the above-mentioned projection type display device has an outer case for housing the optical component housing and the light modulation device therein, and an exhaust fan for discharging the air inside the projection type display device to the outside. It is preferable that an exhaust passage is provided between the lower surface of the optical component housing and the inner bottom surface of the outer case to guide cooling air that has cooled the sealed portion to the exhaust fan.

That is, since the exhaust passage is provided, the cooling air taken in from the cooling fan cools the sealed portion and then is quickly discharged from the exhaust fan through the exhaust passage to cool the sealed portion. The efficiency is further improved. Further, by configuring the exhaust passage in this manner, the structure inside the projection display device can be simplified similarly to the above-described cooling air introduction passage, and the cooling air flows through the lower part of the optical component casing. This makes it possible to cool optical components such as lenses and mirrors disposed inside the housing.

Further, the above-mentioned light modulation device has a pair of substrates and an electro-optical material sandwiched between these substrates, and at least one of the pair of substrates has a thermal conductivity of 10 W / W. It is preferable to employ a light modulator using a material of m · K or more.

That is, since the light modulator includes such a material, the heat generated by the light modulator intercepting a part of the emitted light beam is efficiently exchanged with the air inside the sealed portion. It is possible to significantly improve the cooling efficiency of the light modulation device in the sealed portion.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

(1) Overall Configuration of the Apparatus FIGS. 1 and 2 are schematic perspective views of a projection type display apparatus 1 according to the present embodiment. FIG. 1 is a perspective view as viewed from above, and FIG. It is the perspective view seen from the lower surface side.

The projection display device 1 separates a light beam emitted from a light source lamp into three primary colors of red (R), green (G), and blue (B), and converts each of these color light beams into a liquid crystal constituting a light modulator. Modulation is performed through a panel in accordance with image information, and modulated light fluxes of the respective colors are combined by a prism (color combining optical system) and enlarged and displayed on a projection surface via a projection lens 6. . Except for a part of the projection lens 6, each component is housed inside the outer case 2.

(2) Structure of Outer Case The outer case 2 is basically composed of an upper case 3 that covers the upper surface of the device, a lower case 4 that forms the bottom surface of the device, and a rear case 5 that covers the rear portion (FIG. 2). It is comprised including.

As shown in FIG. 1, a large number of communication holes 25R and 25L are formed on the upper surface of the upper case 3 at the left and right ends on the front side (projection lens side). An operation switch 60 for adjusting the image quality and the like of the projection display device 1 is provided between the communication holes 25R and 25L. Further, an air inlet 230 for introducing cooling air from outside to the inside of the projection display device 1 is provided at the rear end side of the operation switch 60.
Although not shown in FIG. 1, an air filter made of sponge is provided on the inner surface side of the air inlet 230 to prevent dust and the like from entering the inside from the air inlet 230. A light receiving unit 70 for receiving an optical signal from a remote controller (not shown) is provided in a lower left portion of the front surface of the upper case 3.

As shown in FIG. 2, a lamp replacement cover 27 for replacing a light source lamp unit 8 (described later) housed therein is provided on the bottom surface of the lower case 4, and a projection type display is provided. A foot 31C is provided at substantially the center of the front end of the device 1 and a foot 31 is provided at the left and right corners of the rear end.
R and 31L are provided. In addition, the foot 31C can raise the lever 311 shown in FIG.
The rotation mechanism 312 (FIG. 2) on the rear side rotates
As shown by the two-dot chain line in the middle, the front side is urged to open and separate from the apparatus main body. The vertical position of the display screen on the projection plane can be changed by adjusting the amount of rotation. On the other hand, foot 31R, 31
L is configured to advance and retreat in the protruding direction when rotated, and it is possible to change the inclination of the display screen by adjusting the amount of advance and retreat.

As shown in FIG. 2, an AC inlet 45 for supplying external power and various input / output terminal groups 46 are arranged in the rear case 5. An exhaust port 160 for discharging the air is formed.

(3) Internal Structure of the Apparatus FIGS. 3 and 4 show the internal structure of the projection display apparatus 1. FIG.

As shown in these figures, a power supply unit 7 as a power supply, a light source lamp unit 8, an optical unit 10 constituting an optical system, and a pair of upper and lower Driver board 1
1. A main board 12 and the like as a control circuit board are arranged.

The power supply unit 7 includes first and second power supply blocks 7A and 7B arranged on both sides of the projection lens 6. The first power supply block 7A has an AC inlet 4
5 for transforming the electric power obtained through the power supply 5 and supplying it mainly to the second power supply block 7B and the light source lamp unit 8. The power supply circuit includes a transformer (transformer), a rectifier circuit, a smoothing circuit, a voltage stabilizing circuit, and the like. In addition to the substrate, a lamp driving substrate 18 for driving a light source lamp 181 described later of the light source lamp unit 8 is provided. The lamp driving substrate 18 is covered with a transparent resin cover 185. The second power supply block 7B further transforms and supplies the power obtained from the first power supply block 7B. Like the first power supply block 7A, the second power supply block 7B includes a power supply circuit board on which various circuits are formed in addition to a transformer. Have. The power is supplied to another power supply circuit board 13 (shown by a dotted line in FIG. 4) disposed below the optical unit 10 and the first and second intake fans 17A disposed adjacent to the power supply blocks 7A and 7B. , 17B.

In the power supply circuit on the power supply circuit board 13, the power for driving the control circuit on the main board 12 is mainly generated based on the power from the second power supply block 7B. It produces electricity for parts. Here, the second intake fan 17B is disposed between the second power supply block 7B and the projection lens 6, and cools through a gap formed between the projection lens 6 and the upper case 3 (FIG. 1). It is provided so that air is sucked into the inside from the outside. And each power supply block 7A,
7B is a power supply cover member 25 made of conductive material such as aluminum.
0A, 250B, each power supply cover member 250A,
50B, the communication holes 25R, 25L of the upper case 3
Speaker 251R, 25 for audio output at a position corresponding to
1L is provided. These power supply cover members 250
As shown by the dotted line in FIG. 2, the lower portions of A and 250B are electrically connected by a metal plate 252L, and are finally grounded through the GND (ground) line of the inlet 45. The metal plate 252L is fixed to a resin lower case 4 in advance, and its both ends are assembled with the power supply blocks 7A, 7B and the lower case 4 to form power supply cover members 250A, 250B.
Are in contact with each other to make them conductive.

The light source lamp unit 8 constitutes a light source portion of the projection display device 1, and has a light source device including a light source lamp and a reflector, and a lamp housing for accommodating the light source device. Such a light source lamp unit 8 is covered with a housing portion 9021 formed integrally with the lower light guide 902 shown in FIG. 4, and is configured to be detachable from the lamp replacement lid 27 described above. Behind the accommodating portion 9021, a pair of exhaust fans 16 are provided side by side at a position corresponding to the exhaust port 160 of the rear case 5, and as will be described in detail later, these exhaust fans 16 3 intake fans 17A-17C
The cooling air sucked in at the step is introduced into the inside through an opening provided in the vicinity of the housing portion 9021, and after cooling the light source lamp unit 8 with the cooling air, the cooling air is exhausted from the exhaust port 160. are doing. The power of each exhaust fan 16 is supplied from the power supply circuit board 13.

The optical unit 10 is a unit for optically processing a light beam emitted from the light source lamp unit 8 to form an optical image corresponding to image information, and as shown in FIG. , A color separation optical system 924, a light modulation device 925, and a prism unit 910 as a color combining optical system. Optical elements such as a lens and a mirror that constitute the illumination optical system 923 and the color separation optical system 924 are configured to be held vertically by being sandwiched between upper and lower light guides serving as optical component housings ( FIG. 4 shows only the lower light guide 902). These upper light guide and lower light guide 902 are integrated,
It is fixed to the lower case 4 side by a fixing screw.
Although not shown in FIGS. 3 and 4, a gap is provided between the lower surface of the lower light guide 902 and the inner bottom surface of the lower case 4, and communicates with the exhaust port 160.

The prism unit 910 is fixed to a head body 903 having a substantially L-shaped side surface by a fixing screw, and three liquid crystal panels constituting the light modulator 925 are fixed to the side surface of the prism unit 910 via a fixing member. ing. Such a light modulator 925 and the prism unit 91
As will be described in detail later, 0 is covered by the closed box 80 and the mounting portion of the projection lens 6 of the head body 903, and the optical path from the light modulator 925 to the projection lens 6 has a sealed structure.

The driver board 11 is for driving and controlling the three liquid crystal panels constituting the light modulator 925, and is arranged above the optical unit 10. The lower driver board 11A and the upper driver board 11B are stud bolt 9011
, And many elements (not shown) that form a drive circuit and the like are mounted on opposing surfaces of each other. That is, many of these elements are efficiently cooled by the cooling air flowing between the driver boards 11.

The main board 12, on which a control circuit for controlling the whole of the projection type display device 1 is formed, is provided upright beside the optical unit 10. The main board 12 is electrically connected to the driver board 11 and the operation switch 60, and furthermore, the input / output terminal group 4
6 are electrically connected to the interface board 14 and the video board 15 provided with the power supply circuit 6, and are connected to the power supply circuit board 13 via a connector or the like. The control circuit of the main board 12 is driven by power generated by the power supply circuit on the power supply circuit board 13, that is, power from the second power supply block 7B. The main board 12 is cooled by the second intake fan 17B from the second intake fan 17B.
This is performed by cooling air flowing through the power supply block 7B.

In FIG. 3, a guard member 19 made of metal such as aluminum is disposed between the main board 12 and the outer case 2 (only the lower case 4 and the rear case 5 are shown in FIG. 3). The guard member 19 has a large planar portion 191 extending over the upper and lower ends of the main board 12, the upper side is fixed to the cover member 250 </ b> B of the second power supply block 7 </ b> A with fixing screws 192, and the lower end is formed of the lower case 4. For example, the upper case 3 is engaged and supported by a slit. As a result, when the upper case 3 is attached to the lower case 4, interference between the upper case 3 (FIG. 1) and the main board 12 is prevented, and the main board 12 is protected from external noise. I have.

(4) Structure of Optical System Next, the optical system of the projection display device 1, that is, the optical unit 10
Will be described with reference to the schematic diagram shown in FIG.

As described above, the optical unit 10 includes the illumination optical system 923 for uniformizing the in-plane illuminance distribution of the light beam (W) from the light source lamp unit 8, and the illumination optical system 923.
A color separation optical system 924 that separates a light beam (W) from the light into red (R), green (G), and blue (B), and a light modulation device that modulates each color light beam R, G, and B according to image information 925, and a prism unit 910 as a color synthesizing optical system for synthesizing each color light beam after modulation. The light source lamp unit 8 includes a light source lamp 181 and a reflector 182.
Is provided.

The illumination optical system 923 includes a reflection mirror 931 that bends the optical axis 1a of the light beam W emitted from the light source lamp unit 8 toward the front of the apparatus, and a first lens plate 921 that is disposed with the reflection mirror 931 interposed therebetween. And a second lens plate 922. The first lens plate 921 has a plurality of rectangular lenses arranged in a matrix, and divides a light beam emitted from a light source into a plurality of partial light beams. Then, each partial light beam is collected near the second lens plate 922.

The second lens plate 922 has a plurality of rectangular lenses arranged in a matrix, and converts each partial light beam emitted from the first lens plate 921 to a light modulator 92.
5, liquid crystal panels 925R, 925G, 925B
(To be described later).

As described above, in the projection display apparatus 1 of this embodiment, the liquid crystal panels 925R and 925R are controlled by the illumination optical system 923.
25G and 925B can be illuminated with light having substantially uniform illuminance, so that a projection image without illuminance unevenness can be obtained.

The color separation optical system 924 includes a blue-green reflecting dichroic mirror 941 and a green reflecting dichroic mirror 9.
42 and a reflection mirror 943. First, in the blue-green reflecting dichroic mirror 941, the blue light beam B included in the light beam W emitted from the illumination optical system 923 is used.
The green light flux G is reflected at a right angle, and travels toward the green reflection dichroic mirror 942.

The red light beam R passes through the blue-green reflecting dichroic mirror 941, is reflected at a right angle by the rear reflecting mirror 943, and is emitted from the emission section 944 of the red light beam R to the prism unit 910 side. Next, of the blue and green luminous fluxes B and G reflected by the blue-green reflecting dichroic mirror 941, the green reflecting dichroic mirror 94
In 2, only the green light flux G is reflected at a right angle, and is emitted from the emission unit 945 of the green light flux G to the prism unit 910 side. The blue light flux B that has passed through the green reflection dichroic mirror 942 is emitted from the emission section 946 of the blue light flux B toward the relay optical system 927. In this example, the color separation optical system 92 is output from the emission portion of the light beam W of the illumination optical system 923.
4, the emission portions 944, 94 of the respective color light beams R, G, B.
The distances to 5,946 are all set to be equal.

The red and green luminous flux R of the color separation optical system 924
Condensing lenses 951 and 952 are arranged on the emission sides of the G emission sections 944 and 945, respectively. Therefore, the red and green light fluxes R and G emitted from the respective emission portions are incident on these condenser lenses 951 and 952 and are parallelized. The red and green luminous fluxes R and G thus collimated pass through the incident-side polarizing plates 960R and 960G, and the liquid crystal panels 925R,
The light is incident on 925G and modulated, and image information corresponding to each color light is added. That is, these liquid crystal panels 925
The switching of R and 925G is controlled by the driver board 11 in accordance with the image information, so that each color light passing therethrough is modulated. On the other hand, the blue light flux B is guided to the corresponding liquid crystal panel 925B via the relay optical system 927, where it is similarly modulated according to image information. In addition, as the liquid crystal panels 925R, 925G, and 925B of the present embodiment, for example, a liquid crystal panel using a polysilicon TFT as a switching element can be adopted.

The relay optical system 927 includes a condensing lens 954 disposed on the exit side of the exit portion 946 of the blue light beam B, an entrance side reflection mirror 971, an exit side reflection mirror 972, and an arrangement between these reflection mirrors. Intermediate lens 973
Condensing lens 95 arranged on the front side of liquid crystal panel 925B
The blue light flux B emitted from the condenser lens 953 is incident on the liquid crystal panel 925B through the incident-side polarizing plate 960B and is modulated. At this time, the central optical axis 1a of the light beam W and the central optical axis 1 of each of the color light beams R, G, B
r, 1g and 1b are formed substantially in the same plane. The length of the optical path of each color light beam, that is, the distance from the light source lamp 181 to each liquid crystal panel, is the longest for the blue light beam B, and therefore, the loss of the light amount of this light beam is the largest. However, by interposing the relay optical system 927, the light amount loss can be suppressed.

Next, each of the liquid crystal panels 925R, 925G,
The color light beams R, G, and B modulated through 925B are incident on the prism unit 910 through the output-side polarizing plates 961R, 961G, and 961B, and are combined there. That is, the prism unit 910 includes a prism having two types of wavelength selection films arranged substantially in an X-shape inside, and the color light fluxes R, G, and B are combined by the selection characteristics of these two types of wavelength selection films. Is done. The color image synthesized by the prism unit 910 is enlarged and projected on the projection surface 100 at a predetermined position via the projection lens 6.

(5) Closed Box 80 and Head 9
03, the closed box 80 and the head body 903 are, as shown in FIG.
02 is arranged adjacent to the light guide. A light modulator 925 and a prism unit 910 are hermetically housed inside a hermetically sealed section defined by the hermetically sealed box 80 and the head body 903. On the upper surface of the upper case 3 corresponding to the plane position of the prism unit 910, the above-described air inlet 230 is formed, and the closed box 80 and the air inlet 2 are formed.
Between 30, the intake fan 17C is arranged. Further, a gap having a dimension D <b> 1 is formed at a boundary between the light guide and the closed box 80, and the gap is a cooling air introduction path 86. The cooling air introduction passage 86 is formed as a gap having a dimension D2 between the inner bottom surface of the lower case 4 and the lower surface of the lower light guide 902.
It communicates with 8. Note that the planar shape of the closed box 80 is set smaller than the fan diameter of the intake fan 17C, whereby the cooling air from the intake fan 17C easily flows into the cooling air introduction passage 86. Further, the clearance dimension D1 of the cooling air introduction passage 86 is determined by the amount of air blown by the intake fan 17C and the volume inside the sealed portion, and is 1 mm to 1 mm.
It is preferably set to about 0 mm, and most preferably set to 3 mm to 5 mm in consideration of the storage efficiency inside the projection display device 1. A cover member 85 is provided between the boundary portion of the upper light guide 901 and the intake fan 17C so as to surround the above-described cooling air introduction path, and the cooling air taken in from the air intake 230 by the intake fan 17C. Is guided to the cooling air introduction passage 86 by the cover member 85. In addition, a cooling air introduction opening 851 for guiding a part of the cooling air is formed on a side surface of the cover member 85, and a part of the cooling air guided by the cooling air introduction opening 851 is used for the driver board 11 described above. To cool them.

The head body 903 is a member made of a magnesium alloy and has a substantially L-shaped side surface. The substantially L-shaped vertical portion is a projection lens mounting portion 903A to which the projection lens 6 is fixed, and the substantially L-shaped horizontal portion is formed. The prism mounting section 903B on which the prism unit 910 is mounted is fixed. Although not shown in FIG. 6, a seal member is provided between the projection lens mounting portion 903A and the projection lens 6, and air flows in the left and right spaces of the projection lens mounting portion 903A in FIG. Are being regulated. Also, the liquid crystal panels 925R, 925G, 9
A plurality of communication holes are formed in accordance with the arrangement of 25B, and the flow of air in the upper and lower spaces defined by the prism mounting portion 903B is ensured.

The closed box 80 is composed of an upper cover member 81 and a lower cover member 83 made of a magnesium alloy. As shown in FIG. For this purpose, a centrifugal fan 87 is provided. The centrifugal fan 87 sucks air from a direction along the rotation axis of the fan and discharges air in a tangential direction of rotation of the fan. A discharge port 871 for discharging air is connected to the upper cover member 81. It is connected to the air circulation path 90 via the part 814, and a sealing material is interposed at each connection part to ensure airtightness. In this case,
The maximum flow rate of the centrifugal fan 87 is 0.17 m ³ /
min, the maximum static pressure at the outlet 871 is 17.5 mmAq
Is adopted. The air inside the sealed portion is sucked by the centrifugal fan 87, discharged from the air circulation path 90, and supplied again from the lower cover member 83 to the inside of the sealed portion.

The upper cover member 81 is, as shown in FIG.
It comprises a side plate portion 811 arranged so as to surround the liquid crystal panels 925R, 925G, 925B, and an upper plate portion 821 covering the upper surface of the side plate portion 811. LCD panel 92
Side plate portion 81 corresponding to the arrangement of 5R, 925G, 925B
In one portion, three openings 812 are formed to introduce the red light beam R, the green light beam G, and the blue light beam B. Although not shown in FIG. 7, each opening 812
Have the above-described incident side polarizing plates 960R and 960 inside.
G and 960B are attached, and these incident-side polarizing plates 960R, 960G and 960B are provided with respective color light fluxes R and 960B.
The polarization planes of G and B are aligned, and the flow of air inside and outside the closed box 80 is blocked. In addition, three openings 8
12, the liquid crystal panels 925R, 925G, 92
A notch 813 is formed for inserting a flexible printed cable (FPC) 111 that electrically connects the 5B and the driver board 11A. Further, a connection portion 814 for connecting the air circulation path 90 is formed on the upper front surface of the side plate portion 811. Upper plate 821
Are provided at positions corresponding to the positions of the flat portions 823 covering the upper surface of the side plate portion 811 and the cutout portions 813 of the side plate portion 811 on the outer periphery thereof, and the engaging pieces 8 engaging with the cutout portions 813 are provided.
22. Then, when the engaging piece 822 is inserted into the notch 813, the FPC 111
And the side plate portion 811. A rubber packing (not shown) is attached around the FPC 111 to ensure airtightness inside the sealed portion. In this embodiment,
Although the side plate portion 811 and the upper plate portion 821 of the upper cover member 81 are formed by different members, they may be formed by a member in which these are integrated.

The lower cover member 83 is a cylindrical box-shaped member that covers the bottom of the head body 903, and a connecting portion 831 for connecting the air circulation path 90 is formed on the front side surface thereof, similarly to the upper cover member 81. ing. Further, a partition plate 832 is provided inside the lower cover member 83, and serves as a rectifying plate for guiding air from the air circulation path 90. In particular,
As shown in FIG. 8, the arrangement of the partition plate 832 depends on the direction in which air is ejected from the air circulation path 90, the liquid crystal panels 925R,
Determined by the arrangement of 5G and 925B, in the case of this example,
The air A ejected from the air circulation path 90 is
A guides the liquid crystal panel 925B to the lower part of the liquid crystal panel 925B.
You will be guided to the lower part of R.

The above-described upper cover member 81 and lower cover member 83 are attached to the head body 903. The upper cover member 81 is provided on the upper surface side (the prism unit 910 side) of the prism mounting portion 903B and the projection lens mounting portion 90.
The lower cover member 83 is attached to the lower surface side (the opposite side to the prism unit 910) of the prism mounting portion 903B. As shown in FIG. 9, the upper cover member 81 is provided with a fixing piece 81 provided at the bottom of the side plate 811.
5 and a fixing piece 81 provided at an intermediate portion of the side plate portion 811
6 and these fixing pieces 814 and 816 are
17, the prism mounting portion 903B of the head body 903
And it is fixed to the projection lens mounting portion 903A. For this reason, the planar shape of the upper cover member 81 is a rectangular shape in which a portion where the fixing piece 815 is provided is chamfered, and the bolt 817 is formed.
Facilitates screw fixing. Although not shown in FIG. 9, a seal member such as rubber packing is interposed at a contact portion of the upper cover member 81 with the prism mounting portion 903B and the projection lens mounting portion 903A. The hermeticity of the inside and outside of the upper cover member 81 is ensured. The mounting structure of the lower cover member 83 to the head body 903 is substantially the same as the mounting structure of the upper cover member 81, and a description thereof will be omitted.

(6) Structure of Air Circulation Path 90 As shown in FIG. 9, the air circulation path 90 is composed of an aluminum pipe-like member 91 and an elbow 92, the ends of which are connected to the upper cover member 81. 814 and the connecting portion 831 of the lower cover member 83 via a sealing material.

Here, the inner diameter of the pipe-shaped member 91 is determined when the air in the sealed portion is circulated by the centrifugal fan 87.
The three liquid crystal panels 925R and 925 of the light modulation device 925
G, the temperature of 925B rises. Specifically, as shown in FIG.
The evaluation was made based on the rate of temperature rise relative to the reference temperature when the inner diameter of No. 1 was changed to 11 mm to 17 mm. In FIG. 10, a graph G1 indicates a rate of increase in the temperature of the incident surface of the liquid crystal panel 925R.
Graph G2 represents the rate of rise of the incident surface temperature of the liquid crystal panel 925G, graph G3 represents the rate of rise of the incident surface temperature of the liquid crystal panel 925B, and graph G4 represents the representative air temperature inside the closed box 80. As shown in FIG. 10, if the inner diameter of the pipe-shaped member 91 is increased,
It can be seen that the rate of temperature rise of 5R, 925G, and 925B can be reduced, that is, cooling can be performed efficiently.
However, if the inner diameter of the pipe-shaped member 91 is set so as to be larger than the area of the outlet 871 of the centrifugal fan 87 described above, a wasteful portion occurs in space. Depending on the pipe-shaped member 91
Is preferably set to about 10 mm to 30 mm in accordance with the specifications of the centrifugal fan 87.
In the case of this example, the inner diameter of the pipe-shaped member 91 is set to 17 mm in consideration of the opening area of the outlet 871 of the centrifugal fan 87 having the above-described specification. Further, the present embodiment is based on the condition that a liquid crystal panel having a diagonal length of 0.9 inches of a portion used for image display is used, and as the size of the display portion increases or decreases, the centrifugal force used increases. The capacity of the fan is increased or decreased, and accordingly, the inner diameter of the pipe-shaped member 91 adapted to the opening area of the outlet 871 is also increased or decreased.

Although not shown in FIG. 7 and FIG. 8, as shown in FIG.
A heat radiation structure including a plurality of heat radiation fins 93 is provided. The heat radiation fins 93 are aluminum ring-shaped members joined to the outer peripheral surface of the air circulation path 90 by welding or the like.
It is set appropriately according to the cooling efficiency of the internal air.

(7) Description of Cooling Channel Next, the cooling channel formed in the projection display 1 will be described.

In the projection display device 1, FIGS.
As shown schematically by arrows in FIG. 1, a first power supply block cooling flow path 41, a second power supply block cooling flow path 42, a light modulation device cooling flow path 43, and a light source cooling flow path 44 are mainly formed. However, the cooling air flowing through each of the cooling passages 41 to 44 does not strictly flow along the arrows in the drawing, but is drawn and discharged generally as shown by the arrows through the gaps between the components. It is.

The first power supply block cooling passage 41 is a passage for cooling air sucked from the intake port 171 by the first intake fan 17A (FIGS. 3 and 4). The cooling air is
After cooling the first power supply block 7A, the lamp drive board 18 disposed behind the first power supply block 7A is cooled. At this time, the flow of the cooling air is regulated in one direction by flowing through the resin cover 185 having both front and rear ends opened, whereby the flow rate for cooling the lamp driving board 18 is reliably maintained. ing. After this, the cooling air is
Of the light source lamp unit 8 (light source lamp 181), which flows into the housing portion 9021 through an opening portion 9022 provided in the upper portion of the housing portion, another opening portion (not shown), or a gap, and the like, and The air is exhausted from the exhaust port 160 by the exhaust fan 16.

The second power supply block cooling flow path 42 is a flow path for cooling air sucked by the second intake fan 17 B. The sucked cooling air is first supplied to the air disposed on the side of the projection lens 6. After cooling the circulation path 90, it is supplied to the second power supply block 7B. After cooling the second power supply block 7B, the cooling air cools the main board 12 disposed behind the second power supply block 7B, and further flows into the inside through an opening 9023 near the accommodating portion 9021 to enter the light source lamp. The unit 8 is cooled and exhausted from the exhaust port 160 by the exhaust fan 16.

The light modulation device cooling passage 43 is a passage for cooling air sucked by the third intake fan 17C shown in FIG. The cooling air from the third intake fan 17 </ b> C is supplied to the cooling air introduction passage 86 via the cover member 85, cools the entire closed box 80, and partially flows into the cooling air introduction opening 851, so that the driver board 11 (11
A, 11B) is cooled. The cooling air that has cooled the closed box 80 reaches the bottom of the lower case 4, passes through the above-described exhaust passage 88, and is discharged by the exhaust fan 16 through the exhaust port 160.
Is released to the outside. On the other hand, the cooling air that has cooled the driver board 11 flows along the upper surface of the upper light guide 901, and in addition to the openings 9022 and 9023,
After flowing into the housing portion 9021 through the other opening 9024 to cool the light source lamp 181, the light is similarly discharged from the exhaust port 160. If a part of the cover member 85 is provided with an opening through which cooling air flows toward the pipe-shaped member 91 and an air flow path is formed along the pipe-shaped member 91 by the fan 17B, the cooling of the closed box 80 can be further improved. The efficiency is improved. Further, when the fan 17C cannot be arranged in the space, cooling that is practically satisfactory can be obtained only by the fan 17B.

The light source cooling passage 44 is a passage for cooling air sucked from the intake port 172 (FIG. 2) on the lower surface of the lower case 4. The cooling air is sucked by the exhaust fan 16, and after being sucked from the air inlet 172, flows into the interior of the housing 9021 from an opening or a gap provided on the lower surface of the housing 9021, and flows into the light source lamp unit. 8 is cooled and exhausted from the exhaust port 160.

The cooling air in each of the cooling channels 41 to 44 as described above is exhausted from the exhaust port 160 by each exhaust fan 16, and these exhaust fans 16 are controlled according to the temperature state of the heating parts. I have. That is, a temperature sensor 9025 covered with a shrink tube or the like is provided in the vicinity of the opening 9022 on the side of the light source lamp unit 8 where the temperature easily rises, and the second lens plate 922 below the opening 9023 (FIG. 4). In the vicinity, the first and second power supply blocks 7
Similar temperature sensors (not shown) are also provided in the vicinity of the liquid crystal panels A, 7B and the liquid crystal panels 925R, 925G, 925B. For example, electric signals from these temperature sensors 9025 in the cooling passages 41 to 44 are used, for example. It is output to the main board 12 via the power supply circuit board 13 and the like. The main board 12 electrically processes this signal to detect the temperature of the heat-generating component or the cooling air. As a result, when it is determined that the temperature is high, both the exhaust fans 16 are driven simultaneously. If it is determined that the temperature is low and the temperature is low, control is performed such as driving only one exhaust fan 16 to save power.

(8) Circulation of Air Inside Sealed Section Next, circulation and cooling of air inside the sealed section composed of the closed box 80 and the head body 903 will be described.

The rotation of the centrifugal fan 87 sucks up the air inside the sealed portion, and cools the liquid crystal panels 925R, 925G, and 925B constituting the light modulator 925. The air that has cooled the light modulator 925 is discharged from the outlet 871 to the air circulation path 90. Since the air circulation path 90 is cooled by the cooling air flowing through the above-described second power supply block cooling flow path 42, the air cooled by the light modulator 925 loses its heat while flowing through the air circulation path 90. The air is absorbed by the air circulation path 90, and further cooled by heat exchange between the air circulation path 90 and cooling air flowing outside the air circulation path 90. Thereafter, the air is supplied to the lower part of the liquid crystal panel 925B and the liquid crystal panel 925G by the partition plate 832.
, And the liquid crystal panel 925R flows in this order, and is used for cooling the light modulator 925. Since the closed box 80 is also cooled by the cooling air from the third intake fan 17C, the heat inside the closed portion is absorbed by the closed box 80, and the air inside the closed portion is further cooled.
The cooling is performed by performing heat exchange between the cooling air and the outside cooling air.

(9) Effects of the Embodiment According to the above-described embodiment, the following effects can be obtained.

That is, since the air circulation path 90 is disposed in the second power supply block cooling flow path 42, the air flowing through the air circulation path 90 is cooled through heat exchange with the cooling air. Then, the air in the cooled air circulation path 90 circulates through the inside of the closed portion, so that the light modulation device 925 can be efficiently cooled. Further, since the air in the sealed portion is circulated only in the sealed portion and the air circulation path 90, dust and oil smoke do not enter from the outside, and the image quality of the projection display device 1 is stably maintained for a long time. Can be secured.

Also, an aluminum pipe-like member 91
Since the heat radiation is high, the air in the air circulation path can be cooled more efficiently if it is disposed in the second power supply block cooling flow path 42. Further, since the air inside the sealed portion is circulated by the centrifugal fan 87 and the inner diameter of the pipe-shaped member 91 is set to 17 mm according to the centrifugal fan 87, the light modulator 925 can be efficiently cooled. Can be.

Further, since the air circulation path 90 is detachable from the connection portions 814 and 831 of the sealed portion, maintenance of the light modulator 925, the centrifugal fan 87 and the like inside the sealed portion can be easily performed. The air circulation path 90
Since the connecting portions 814 and 831 are connected via the sealing material, it is possible to reliably prevent air leakage inside the sealing portion. Furthermore, since the sealed box 80 made of a magnesium alloy and the air circulation path 90 made of aluminum are connected via a sealing material such as rubber, electric illumination is not generated at the dissimilar metal joining portion, and the sealed portion is not formed. The airtightness is permanently ensured.

Since the air circulation path 90 has the heat radiation structure including the ring-shaped heat radiation fins 93, the air inside the air circulation path 90 is more efficiently formed in the second power supply block cooling flow path 42. Can be cooled.

Further, since the air circulation path 90 is arranged on the side of the projection lens 6, the dead space on the side of the projection lens 6 is effectively used, which is advantageous for miniaturizing the projection display device 1. Becomes

Further, since the second intake fan 17B is provided near the air circulation path 90, the second intake fan 1
By introducing the cooling air of 7B, the air circulation path 90 can be cooled more efficiently.

Since a cooling air introduction passage having a clearance dimension D1 is formed between the light guide and the sealing portion,
The entire enclosed portion can be cooled by the cooling air taken in from the third intake fan 17C, and the air inside the enclosed portion is more efficiently cooled together with the air circulation path 90, and the temperature of the light modulator 925 increases. Can be prevented.

Further, since the cooling air introduction passage is formed as a gap between the light guide and the sealing portion, the inside of the projection display device 1 can be cooled without providing a separate duct or the like, and The structure inside the display device 1 can be simplified.

Further, since the cover member 85 is provided between the light guide and the third intake fan 17C,
The cooling air from the third intake fan 17C can be guided to the cooling air introduction path as necessary and sufficiently, and the cooling efficiency of the sealed portion can be further improved.

Since the cooling air introduction opening 851 is formed in the cover member 85, the third intake fan 17
The cooling air from C can be guided to the driver board 11 to be cooled, and the heated portion inside the projection display device 1 can be appropriately cooled. Further, since an exhaust passage having a clearance dimension D2 is provided between the lower surface of the light guide and the inner bottom surface of the lower case 4, the cooling air that has cooled the sealed portion is quickly exhausted through the exhaust passage. 16
And the cooling efficiency of the sealed part is further improved. In addition, since the cooling air flows under the light guide, optical components such as a lens and a mirror disposed inside the light guide can be cooled.

(11) Modifications of Embodiment The present invention is not limited to the above-described embodiments, but includes the following modifications.

In the above-described embodiment, the air circulation path 90 is disposed in the second power supply block cooling flow path 42. However, the air circulation path may be disposed in the first power supply block cooling flow path 41. In short, if the air circulation path is arranged in the cooling channel that cools the inside of the projection display device, the same operations and effects as those described in the above embodiment can be obtained.

In the above embodiment, the air circulation path 90
Is a pipe member 91 made of aluminum and an elbow 9
However, the air circulation path may be formed of a pipe-shaped member made of another metal such as copper having a good thermal conductivity. The air circulation path may be configured to be bent in a circular shape. In addition, if the air circulation path is configured in this way, the pressure loss in the pipe inside the air circulation path is reduced, and the air in the sealed portion can be rapidly circulated.

Further, the heat radiating structure of the air circulation path 90 in the above embodiment is constituted by the ring-shaped heat radiating fins 93 provided on the pipe-shaped member 91, but is not limited to this. That is, as shown in FIG. 12, a linear material 96 having a linear core material 94 and a plurality of heat radiation pieces 95 projecting radially outward of the core material 94 is spirally wound around the air circulation path 90. The heat dissipation structure may be formed by winding the heat dissipation structure.

In the above embodiment, the light modulator 9
25 is a TFT driven liquid crystal panel 925R, 925G,
925B, but not limited to this, TN,
The present invention may be applied to a projection display device including a light modulation device configured by another driving method such as STN.

In the above embodiment, the light modulator 92
5 is three liquid crystal panels 925R, 925G, 925B
However, the present invention is not limited to this, and the present invention may be applied to a light modulation device including one or two liquid crystal panels.

Further, the liquid crystal panels 925R, 925G,
925B, at least one of the two glass members for sealing the liquid crystal is made of a plate material having a thermal conductivity of a normal material.
The material may be changed to a material of 10 W / m · K or more with respect to 2 W / m · K, for example, sapphire glass containing aluminum oxide. By adopting sapphire glass, the thermal conductivity is improved to 42 W / mK, and the heat generated in the liquid crystal panel by intercepting a part of the light to be modulated is very efficiently transferred to the air inside the sealed part. It can be exchanged, and the cooling efficiency of the light modulator in the sealed portion can be significantly improved.

In the above embodiment, the light modulator 9
Although the panel constituting the liquid crystal element 25 is composed of a liquid crystal element, the present invention may be applied to a projection display apparatus including a light modulation device composed of a panel using a plasma element other than a liquid crystal and a micromirror. .

Further, the light modulation device 9 in the above embodiment
25 is a type that transmits and modulates the light fluxes R, G, and B, but is not limited thereto, and includes a reflection-type light modulation device that modulates and emits incident light while reflecting it. The present invention may be applied to a type display device.

In addition, specific structures, shapes, and the like at the time of carrying out the present invention may be other structures and the like as long as the object of the present invention can be achieved.

[0097]

According to the present invention as described above, since the air circulation path is disposed in the flow path of the cooling air formed inside the projection type display device, the air circulation path can be cooled while the air circulation path is cooled. The air flowing in the road is also cooled, and the cooled air circulates in the sealed portion, so that the optical modulator can be efficiently cooled. In addition, since air circulates through the light modulation device only in the closed part and the air circulation path, there is no intrusion of external dust, oily smoke, etc., regardless of the use environment, and
Maintenance-free image quality of the projection display device can be stably secured for a long period of time.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a projection display device according to an embodiment of the present invention as viewed from above.

FIG. 2 is an external perspective view of the projection display device according to the embodiment as viewed from below.

FIG. 3 is a perspective view illustrating an internal structure of the projection display device according to the embodiment.

FIG. 4 is a perspective view showing an optical system inside the projection display device in the embodiment.

FIG. 5 is a schematic diagram for explaining a structure of an optical system in the embodiment.

FIG. 6 is a vertical sectional view showing a structure of a sealing portion in the embodiment.

FIG. 7 is an external perspective view of a sealing portion in the embodiment.

FIG. 8 is a plan view illustrating an internal structure of a lower cover member that constitutes a sealing portion in the embodiment.

FIG. 9 is a plan view illustrating an attachment structure of an upper cover member that constitutes a closed portion in the embodiment.

FIG. 10 is a graph showing a relationship between an inner diameter of a pipe-shaped member constituting an air circulation path in the embodiment and a temperature rise rate of a light modulation device inside a sealed portion.

FIG. 11 is a perspective view illustrating a heat radiation structure provided in an air circulation path in the embodiment.

FIG. 12 is a perspective view illustrating a heat dissipation structure that is a modification of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Projection display apparatus 2 Exterior case 6 Projection lens 8 Light source 11 Drive circuit board 16 Exhaust fan 17B Cooling fan 17C Intake fan 42 Cooling air flow path 85 Cover member 86 Cooling air introduction path 88 Exhaust flow path 90 Air circulation path 91 Pipe Member 93 heat radiation fins 94 core material 95 heat radiation piece 96 linear material 851 cooling air introduction opening 925 light modulator D1 clearance dimension of cooling air introduction flow path

Claims (14)

[Claims] 1. A projection display comprising a light source, a light modulator for modulating a light beam emitted from the light source according to image information, and a projection lens for enlarging and projecting an image formed by the light modulator. An apparatus, comprising: a sealing portion that seals an optical path from the light modulation device to the projection lens; and an air circulation passage that circulates air in the sealing portion, wherein the air circulation passage is the projection display device. A projection display device, wherein the projection display device is disposed in a flow path of cooling air formed inside the device. 2. The projection type display device according to claim 1, wherein said air circulation path is constituted by a metal pipe-shaped member. 3. The projection type display device according to claim 1, wherein the air circulation path is detachable from the sealing part, and the air circulation path and the sealing part are sealing materials. A projection display device, which is connected via a computer. 4. The projection display device according to claim 1, wherein the air circulation path has a heat radiation structure for releasing heat inside the circulation path to the outside. Projection type display device. 5. The projection type display device according to claim 4, wherein said heat radiation structure comprises a plurality of heat radiation fins extending along a radially outer side of said air circulation path. Display device. 6. The projection display device according to claim 4, wherein the heat radiation structure includes a linear core material and a plurality of heat radiation pieces projecting radially outward of the core material. A projection type display device, wherein a shape member is spirally wound around the air circulation path. 7. The projection display device according to claim 1, wherein said air circulation path is arranged on a side of said projection lens. 8. The projection display device according to claim 1, wherein a cooling fan for cooling the inside of the projection display device is provided near the air circulation path. Projection type display device characterized by the above-mentioned. 9. The projection display device according to claim 1, wherein an optical component such as a lens and a mirror is housed and arranged, and an optical component housing arranged adjacent to said sealing portion is provided. Above the sealing unit, an intake fan that takes in external air inside the projection display device is arranged, and at a boundary between the sealing unit and the optical component casing,
A projection type display device, wherein a cooling air introduction passage for guiding cooling air taken in from the intake fan is formed. 10. The projection display device according to claim 9, wherein the cooling air introduction flow path is a gap formed along a boundary between the sealing portion and the optical component casing. A projection display device, wherein the dimensions are set to 1 mm to 10 mm. 11. The projection display device according to claim 9, wherein a boundary between the optical component casing along the cooling air flow path and the intake fan is provided. A projection display device, wherein a cover member is provided so as to surround the cooling air flow path. 12. The projection display device according to claim 11, further comprising a drive circuit board disposed on the optical component housing for driving the light modulation device, wherein the cover member includes a drive circuit board for driving the light modulation device. A projection type display device, wherein a cooling air introduction opening for guiding a part of the cooling air from the cooling fan is formed in the circuit board. 13. The projection type display device according to claim 9, wherein an outer case for housing the optical component casing and the light modulation device therein, and the interior of the projection type display device. An exhaust fan for exhausting air to the outside, and an exhaust flow that guides cooling air that has cooled the closed part to the exhaust fan, between a lower surface of the optical component casing and an inner bottom surface of the outer case. A projection display device comprising a road. 14. The projection type display device according to claim 1, wherein the light modulation device includes a pair of substrates and an electro-optical material sandwiched between the substrates. A projection display device comprising: a material having a thermal conductivity of 10 W / m · K or more for at least one of the pair of substrates.