JP2000162708A - Projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type display device capable of efficiently cooling an optical modulator, and also, capable of stably securing image quality for a long period. SOLUTION: An electrooptical device including the optical modulator 925 and a prism unit 910 which constitute the projection type display device is stored in a sealed structure constituted of a sealed box 80 and a head body 903, besides, a circulation fan 87 for making an air forcibly circulate in the sealed structure is installed on the electrooptical device. Since the circulation fan 87 is installed inside the sealed structure, the electrooptical device is efficiently cooled by executing a heat exchange between the circulating air and the electrooptical device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source, an electro-optical device 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 electro-optical device. The present invention relates to a projection display device provided with:

[0002]

2. Description of the Related Art Conventionally, a projection system includes 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. Type display devices 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.

[0003] Such a light modulation device employs, for example, a liquid crystal panel using a polysilicon TFT as a switching element. Since this light modulation device is an important part for forming an optical image according to image information, there is a problem that if dust, oily smoke, etc. adhere to the surface of a liquid crystal panel or the like, the image quality of the projection display device is deteriorated. is there. For this reason, it is conceivable to employ a projection display device having a sealed structure for sealing the optical path from the light modulation device to the projection lens.
If it is a projection display device having such a sealed structure,
The sealed structure prevents dust and oil smoke from entering from outside, so that dust and oil smoke do not adhere to the LCD panel surface, and the image quality of the projection display device can be stably secured for a long time. It is suitable as a stationary projection display device such as a ceiling-hanging type.

[0004]

However, since a light modulation device such as a liquid crystal panel is generally weak to heat, as described above, if the light path from the light modulation device to the projection lens is closed by a closed structure. In addition, there is a problem that it is difficult to efficiently cool the optical 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]

A projection display apparatus according to the present invention is formed by a light source, an electro-optical device for modulating a light beam emitted from the light source in accordance with image information, and the electro-optical device. A projection lens for enlarging and projecting an image, comprising: an electro-optical device mounting portion on which the electro-optical device is mounted, and an electro-optical device mounting portion provided substantially perpendicular to the electro-optical device mounting portion. A structure provided with a projection lens attaching portion for attaching the projection lens, a sealing member attached to the electro-optical device mounting portion, and sealing an optical path from the electro-optical device to the projection lens; and a sealing member. An air circulation path that is connected and circulates air inside the sealed structure formed by the structure and the sealing member,
A circulation fan disposed inside the closed structure.

According to the present invention, since the circulation fan is provided inside the closed structure, the air inside the closed structure can be forcibly circulated through the air circulation path by the circulation fan. . Therefore, by performing heat exchange between the air circulating inside the closed structure and the electro-optical device, the electro-optical device can be efficiently cooled. Further, since the electro-optical device is hermetically sealed by the above-described sealing structure, dust and the like do not adhere to the electro-optical device, and image quality can be stably secured for a long period of time.

In the above, it is preferable that the circulating fan employs a centrifugal fan for discharging air taken in by the rotation of the fan in a tangential direction of the rotation.

That is, by employing a centrifugal fan, it is possible to increase the pressure of the air at the time of discharge. Therefore, it is possible to reliably circulate the air inside the closed structure by utilizing the magnitude of the discharge pressure. It becomes possible. In addition, since the centrifugal fan has a higher discharge pressure than a normal axial fan, it can be rotated at a low rotation speed to minimize noise caused by the rotation of the fan.

It is preferable that the centrifugal fan described above is disposed above the electro-optical device, and the suction surface thereof faces the mounting portion of the electro-optical device.

That is, since the centrifugal fan is disposed above the electro-optical device, and its intake surface faces the mounting portion of the electro-optical device, the electro-optical device is provided with an air circulation flow on the suction side of the centrifugal fan. The electro-optical device can be uniformly cooled.

Further, a flange protruding radially outward of the projection lens is provided at a base end side of the projection lens. By joining this flange to a projection lens mounting portion, the projection lens becomes When mounted on a structure, the centrifugal fan described above is arranged at a portion corresponding to a region radially inward from the outer peripheral edge of the flange so as not to protrude radially outward of the outer peripheral edge of the flange. Is preferred.

That is, if the centrifugal fan is arranged in this manner, it is possible to prevent the centrifugal fan from protruding outside the flange, and to reduce the size of the hermetically sealed structure, thereby achieving the projection type display. The device can be reduced in size and thickness.

Preferably, the above-mentioned air circulation path comprises a pipe-shaped member having one end connected to the outlet of the centrifugal fan and the other end connected to the lower portion of the sealing member.

That is, since the pipe-shaped member constituting the air circulation path is connected to the outlet of the centrifugal fan, all of the air sucked into the centrifugal fan by cooling the electro-optical device flows through the air circulation path. It circulates through the constituent pipe-shaped members. Therefore, if this pipe-shaped member is arranged and cooled in the flow path of the cooling air inside the projection display device, the air inside the sealed structure can be efficiently cooled by heat exchange between the pipe-shaped member and air. Becomes possible. By jetting the cooled air from the connection portion at the other end, it is possible to provide cooling for the electro-optical device.

In the case where the electro-optical device includes a plurality of light modulators for modulating an emitted light beam according to image information,
It is preferable that a rectifying plate for proportionally distributing the air ejected from the air circulation path according to the arrangement of the plurality of light modulators is provided inside the above-described sealing member.

That is, since the current plate is provided,
The air cooled in the air circulation path can be guided in accordance with the heat generation state of the plurality of light modulation devices, and the electro-optical device can be cooled more efficiently.

Further, a red light modulator, a green light modulator, in which a plurality of light modulators modulate each of red, green, and blue,
And in the case of a blue light modulator, the above-mentioned rectifying plate is:
It is preferable to guide the air ejected from the air circulation path in the order of the blue light modulator, the green light modulator, and the red light modulator.

That is, of the above-mentioned modulation elements, the blue light modulator has the highest heat value, followed by the green light modulator and the red light modulator. Therefore, by guiding the air from the air circulation path in such an order, it becomes possible to appropriately cool each light modulation device as needed.

In the case where the above-described electro-optical device includes a light modulator that modulates a light beam according to image information,
Preferably, a gap of 1 mm to 5 mm is formed between the sealing member and the light modulation device, and more preferably, the gap is set to 3 mm.

That is, if such a gap is formed between the sealing member and the light modulation device, the air inside the sealing structure can be appropriately circulated along this gap, so that the electro-optic The device can be cooled more efficiently. If the gap size of the gap is 5 mm or more, the flow velocity of the air flowing in the gap becomes slow, and the optical modulator cannot be efficiently cooled.
This is because if it is less than mm, it is difficult to manage the arrangement accuracy of the side plate portion and the light modulation device.

[0022]

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, on the upper surface of the upper case 3, a large number of communication holes 25R and 25L are formed 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 Device FIGS. 3 and 4 show the internal structure of the projection display device 1. FIG.

As shown in these figures, a power supply unit 7 serving as a power supply, a light source lamp unit 8, an optical unit 10 forming an optical system, and a pair of upper and lower members serving as a light modulation device driving board are provided inside the outer case 2. 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, 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 by a fixing screw, and the three liquid crystal panels constituting the light modulation device 925 are:
It is fixed to a side surface of the prism unit 910 via a fixing member. The electro-optical device including such a light modulation device 925 and the prism unit 910 will be described later in detail, but is covered by the closed box 80 and the mounting portion of the projection lens 6 of the head body 903, and the light modulation device 925 transmits the projection lens 6 The optical path up to this is 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 is provided with a control circuit for controlling the whole of the projection display device 1, and 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 reflecting mirror 931 that bends the central optical axis 1a of the light beam W emitted from the light source lamp unit 8 toward the front of the device, and a reflecting mirror 931.
A first lens plate 921 having a first lens plate 921 and a second lens plate 922 disposed with the
Has a plurality of rectangular lenses arranged in a matrix, divides a light beam emitted from a light source into a plurality of partial light beams, and condenses each partial light beam 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 into 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 the present 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 unit 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 condenser 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. Closed box 80 and head body 90 as a structure
3, the light modulation device 9
An electro-optical device including the prism unit 25 and the prism unit 910 is hermetically housed. Also, the prism unit 910
The above-described air intake 230 is formed on the upper surface of the upper case 3 corresponding to the plane position of the above, and an intake fan 17C is arranged between the closed box 80 and the air intake 230. 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 has a dimension D2 between the inner bottom surface of the lower case 4 and the lower surface of the lower light guide 902.
Are communicated with an exhaust passage 88 formed as a gap.
Note that the planar shape of the closed box 80 is the intake fan 17C.
, The cooling air from the intake fan 17 </ b> C easily flows into the cooling air introduction passage 86. Further, the gap 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 closed structure, and is preferably set to about 1 mm to 10 mm. In consideration of the above, it is most preferable to set the distance to 3 mm to 5 mm. The boundary between the upper light guide 901 and the intake fan 17
C, a cover member 85 is provided so as to surround the above-described cooling air introduction passage, and the cooling air taken in from the air inlet 230 by the intake fan 17C is cooled by the cooling air introduction passage 86 by the cover member 85. Will be guided to.
Note that a cooling air introduction opening 851 that guides 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:
These are cooled by being guided by the driver board 11 described above.

The head body 903, which is a structural body, is a member made of a magnesium alloy and has a substantially L-shaped side surface, and a substantially L-shaped vertical portion has a projection lens mounting portion 903 to which the projection lens 6 is fixed.
A, and the substantially L-shaped horizontal portion is an electro-optical device mounting portion 903B on which the electro-optical device is mounted and fixed. FIG.
Although not shown in the drawings, a flange is formed on the base end side of the projection lens 6 toward the outside in the radial direction of the projection lens 6, and the flange and the projection lens mounting portion 903 </ b> A are joined by a fixing screw to form the projection lens 6. Denotes a projection lens mounting portion 903
A is attached. Also, the projection lens mounting section 90
A sealing material is provided between 3A and the projection lens 6,
The flow of air in the left and right spaces of the projection lens mounting portion 903A in FIG. 6 is restricted.
Further, a plurality of communication holes are formed in the electro-optical device mounting portion 903B in accordance with the arrangement of the liquid crystal panels 925R, 925G, and 925B, and air flows in upper and lower spaces defined by the electro-optical device mounting portion 903B. Is secured.

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. Part 814
Are connected to the air circulation path 90 via a seal member. In this case, the maximum flow rate of the centrifugal fan 87 is 0.17 m.
³ / min, maximum static pressure at outlet 871 is 17.5
The one of mmAq is adopted. The air inside the closed structure 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 closed structure.

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 81
2, a glass plate is attached, and the above-mentioned incident side polarizing plates 960R, 960G, and 960B are attached inside the glass plate. The glass plate is affixed to the side plate portion 811 via a sealing material to block the flow of air inside and outside the sealed structure.

Further, as shown in FIG.
A gap is provided between the liquid crystal panels 925R, 925G, and 925B, and the gap dimension D3 is set to approximately 3 mm. This is, as shown in FIG.
3, the wind speed of the air flowing between the gaps increases, and if the wind speed increases, each liquid crystal panel 925R,
The setting is made in consideration of the point that the cooling efficiency of 925G and 925B is improved. In the case of this example, the gap dimension D3 is set to 3 mm because the side plate portion 811 and the liquid crystal panels 925R and 925
This is because the mounting tolerances of G, 925B and the like are taken into consideration, and if the mounting can be performed with high accuracy, it may be smaller. still,
In FIG. 8, a graph G1 shows a case where the centrifugal fan 87 is rotated at the maximum voltage, a graph G2 shows a case where the centrifugal fan 87 is rotated at the reference voltage, and a graph G3 shows a case where the centrifugal fan 87 is rotated at the minimum voltage. The change of the wind speed in the gap portion in the case.

Further, as shown in FIG.
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 structure. In the present embodiment, the side plate portion 811 and the upper plate portion 821 of the upper cover member 81 are formed as separate members, but may be formed as an integrated member.

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. 9, 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 attached to the upper surface side (the prism unit 910 side) of the electro-optical device mounting portion 903B and the surface of the projection lens attachment portion 903A opposite to the surface on which the projection lens 6 is attached. 83 is the lower surface side of the electro-optical device mounting portion 903B (the prism unit 910).
On the other side). The upper cover member 81 is
As shown in FIG. 10, a fixing piece 815 provided at the bottom of the side plate portion 811 and a fixing piece 816 provided at an intermediate portion of the side plate portion 811 are provided.
Are fixed to the electro-optical device mounting portion 903B and the projection lens mounting portion 903A of the head body 903 by bolts 817. 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,
The bolt 817 is easily screwed and fixed. FIG.
Although the illustration is omitted in FIG. 0, a seal member such as a rubber packing is interposed at a contact portion of the upper cover member 81 with the electro-optical device mounting portion 903B and the projection lens mounting portion 903A. The tightness of the inside and outside of the upper cover member 81 is ensured. Head body 9 of lower cover member 83
The mounting structure of the upper cover member 81 is substantially the same as the mounting structure of the upper cover member 81, and a description thereof will be omitted.

(6) Structure of the Air Circulation Path 90 As shown in FIG. 10, 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 by the three liquid crystal panels 925R and 925 of the light modulator 925 when the air in the sealed structure is circulated by the centrifugal fan 87.
It is determined by how much the temperature of 25G and 925B rises. Specifically, as shown in FIG. 11, the evaluation is made based on the temperature rise rate with respect to the reference temperature when the inner diameter of the pipe-shaped member 91 is changed to 11 mm to 17 mm. Note that FIG.
In the graph, graph G4 represents the rate of increase of the incident surface temperature of liquid crystal panel 925R, graph G5 represents the rate of increase of the incident surface temperature of liquid crystal panel 925G, graph G6 represents the rate of increase of the incident surface temperature of liquid crystal panel 925B, and graph G7 is closed. This represents the representative air temperature inside the box 80. As shown in FIG.
It is understood that if the inner diameter of the pipe-shaped member 91 is increased, the rate of temperature rise of each of the liquid crystal panels 925R, 925G, and 925B can be reduced, that is, cooling can be performed efficiently. However, the outlet 871 of the centrifugal fan 87 described above.
If the inner diameter of the pipe-shaped member 91 is set so as to be larger than the area of the pipe-shaped member 91, a useless portion occurs in terms of space. Preferably, the centrifugal fan 87
It is preferable to set the distance to about 10 mm to 30 mm in accordance with the specification. In the case of this example, the centrifugal fan 87 having the above-described specification is used.
Of the pipe-like member 91 in consideration of the opening area of the outlet 871
Is set to 17 mm in inner diameter. In addition, the present embodiment
The diagonal length of the part used for image display is a condition assuming a liquid crystal panel of 0.9 inches, and as the size of the display part increases or decreases, the capacity of the centrifugal fan used is increased or decreased, Along with this, the inner diameter of the pipe-shaped member 91 that matches the opening area of the outlet 871 also increases or decreases.

Although not shown in FIGS. 9 and 10, a heat radiation structure composed of a plurality of heat radiation fins 93 is provided on the outer periphery of the pipe-shaped member as shown in FIG. The radiation fins 93 are provided in the air circulation path 90.
Is a ring-shaped member made of aluminum which is joined to the outer peripheral surface by welding or the like, and the number of the radiation fins 93 is appropriately set according to the cooling efficiency of the air inside the air circulation path 90.

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

In the projection type 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 passage 42 is a passage for the 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 to 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 passages 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 component. 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 Hermetic Structure Next, circulation and cooling of air inside hermetic structure composed of the hermetic box 80 and the head body 903 will be described.

The air inside the sealed structure is sucked up by the rotation of the centrifugal fan 87, and the liquid crystal panels 925R, 925G, and 925B constituting the light modulator 925 are cooled.
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 925 by the partition plate 832.
It flows in the order of the lower part of G and the lower part of the liquid crystal panel 925R, and is used for cooling these light modulation devices 925. Note that the closed box 80 is cooled by the cooling air from the third intake fan 17C.
Since the inside of the closed structure is also cooled, the heat of the air inside the closed structure is absorbed by the closed box 80, and further, the air is cooled by performing heat exchange between the closed box 80 and the cooling air outside.

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

That is, since the centrifugal fan 87 serving as a circulation fan is provided inside the closed structure, the air inside the closed structure can be forcibly circulated through the air circulation path 90. Therefore, by performing heat exchange between the air circulating inside the sealed structure and the liquid crystal panels 925R, 925G, 925B, the liquid crystal panels 925R, 925G,
The electro-optical device including 925B can be efficiently cooled. In addition, since the electro-optical device is hermetically sealed by the hermetic structure including the head body 903 and the closed box 80, dust and the like do not adhere to the electro-optical device, and image quality can be stably secured for a long time. .

Further, by employing a centrifugal fan 87 as a forced circulation device inside the sealed structure, the outlet 8
Since the pressure of the air exhausted from 71 can be increased, the air inside the closed structure can be reliably circulated using the magnitude of the discharge pressure. Since the centrifugal fan 87 has a higher discharge pressure than a normal axial fan, the centrifugal fan 87 can be rotated at a low rotation speed to minimize noise caused by the rotation of the fan.

Further, since the centrifugal fan 87 is arranged above the electro-optical device and its intake surface faces the electro-optical device, it is arranged in the air circulation flow on the suction side of the centrifugal fan 87. Thus, the liquid crystal panel surface of the light modulation device 925 constituting the electro-optical device can be uniformly cooled.

Since the pipe-like member 91 constituting the air circulation path 90 is connected to the centrifugal fan 87,
All of the air sucked into the centrifugal fan 87 after cooling the electro-optical device flows through the pipe-shaped member 91. Therefore, the air circulation path 90 is disposed in the second power supply block cooling flow path 42 and is cooled by the cooling air flowing inside the projection display device. Air can be efficiently cooled. Then, the cooled air is ejected from the connection portion 831 at the other end of the air circulation path 90, so that it can be used for cooling the electro-optical device.

Further, since the partition plate 832 serving as a rectifying plate is provided inside the lower cover member 83, the liquid crystal panel 92 is provided.
According to the arrangement of 5R, 925G, and 925B, the air ejected from the connection portion 831 of the air circulation path 90 can be guided, and the cooling of the electro-optical device can be performed more efficiently. In particular, the partition plate 832 is a liquid crystal panel 925B for modulating a blue light beam, and a liquid crystal panel 92 for modulating a green light beam.
Since the air is guided in the order of 5G and 925R for modulating the red light flux, the liquid crystal panels 925R, 925G, and 925B can be appropriately cooled in the order of the heat generation.

Further, the side plate 811 of the closed box 80
Since the gap D3 between the liquid crystal panels 925R, 925G, and 925B is set to about 3 mm, the wind speed of the air flowing through the gaps is sufficiently ensured and the liquid crystal panels 925R,
5G and 925B can be appropriately cooled.

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

That is, in the above-described embodiment, the circulating fan disposed inside the hermetic structure is the centrifugal fan 87. However, the present invention is not limited to this, and an axial fan usually used for cooling the inside of the projection display device is employed. May be.

In the above embodiment, the centrifugal fan 8
7 is provided so as to protrude from the projection lens mounting portion 903A of the head body 903, but is not limited to this. That is, a flange protruding radially outward of the projection lens is provided on the base end side of the projection lens 6, and the projection lens 6 is attached to the structure 903 by joining this flange to the projection lens mounting portion 903A. When mounted, the centrifugal fan may be arranged at a portion corresponding to a region radially inside the outer peripheral edge of the flange so as not to protrude radially outward of the outer peripheral edge of the flange.

By arranging the centrifugal fan in this manner, the height of the hermetically sealed structure can be reduced, so that the projection display device can be easily reduced in size and thickness.

Further, 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.

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 when the present invention is implemented may be other structures and the like as long as the object of the present invention can be achieved.

[0085]

According to the projection type display apparatus of the present invention as described above, since the circulation fan is provided inside the closed structure, the air inside the closed structure is forcibly forced through the air circulation path by the circulation fan. By performing heat exchange between the air circulating inside the closed structure and the electro-optical device, the electro-optical device can be efficiently cooled. Further, since the electro-optical device is hermetically sealed by the above-described sealing structure, dust and the like do not adhere to the electro-optical device, and image quality can be stably secured for a long 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 graph showing a relationship between a gap size of a gap between the sealing member and the light modulation device in the embodiment and a wind speed of air flowing through the gap.

FIG. 9 is a plan view illustrating an internal structure of a lower cover member that constitutes a sealing unit in the embodiment.

FIG. 10 is a plan view illustrating an attachment structure of an upper cover member that constitutes a sealing portion in the embodiment.

FIG. 11 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. 12 is a perspective view illustrating a heat radiation structure provided in an air circulation path in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Projection type display apparatus 6 Projection lens 80 Airtight box (sealing member) 87 Centrifugal force fan (circulation fan) 90 Air circulation path 91 Pipe-shaped member 181 Light source lamp (light source) 832 Partition plate (rectifier plate) 871 Outlet 903A Projection lens Mounting part 903B Electro-optical device mounting part 925 Light modulator W Light flux

Claims (8)

[Claims] A projection display comprising a light source, an electro-optical device 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 electro-optical device. An electro-optical device mounting portion for mounting the electro-optical device, and provided substantially perpendicular to the electro-optical device mounting portion,
A structure having a projection lens mounting portion for mounting the projection lens, a sealing member attached to the electro-optical device portion, and sealing a light path from the electro-optical device to the projection lens; A projection display device, comprising: an air circulation path configured to circulate air inside a sealed structure including the structure and the sealing member; and a circulation fan disposed inside the sealed structure. 2. The projection display device according to claim 1, wherein said circulation fan is a centrifugal fan for discharging air taken in by rotation of the fan in a tangential direction of rotation. Display device. 3. The projection display device according to claim 2, wherein the centrifugal fan is disposed above the electro-optical device, and a suction surface thereof faces the electro-optical device mounting portion. Characteristic projection display device. 4. The projection display device according to claim 3, wherein a flange protruding outward in a radial direction of the projection lens is provided at a base end side of the projection lens, and the flange is attached to the projection lens. The centrifugal fan is attached to a portion corresponding to a radially inner region of the outer peripheral edge of the flange, by joining the projection lens to the structure. A projection display device, wherein the projection display device is arranged so as not to protrude radially outward. 5. The projection display device according to claim 3, wherein one end of the air circulation path is connected to an outlet of the centrifugal fan, and the other end is a lower portion of the sealing member. A projection display device comprising a pipe-shaped member connected to the display device. 6. The projection display device according to claim 5, wherein the electro-optical device includes a plurality of light modulators that modulate the light beam according to the image information, A projection display device, comprising: a rectifying plate for proportionally dividing the air ejected from the air circulation path according to the arrangement of the plurality of light modulation devices. 7. The projection display device according to claim 6, wherein the plurality of light modulators modulate red, green, and blue light beams, respectively, a red light modulator, a green light modulator, and a blue light. A modulator, wherein the rectifying plate is configured to guide air ejected from the air circulation path in the order of the blue light modulator, the green light modulator, and the red light modulator. A projection display device characterized by the above-mentioned. 8. The projection display device according to claim 1, wherein the electro-optical device includes a light modulator that modulates the light beam according to the image information, and the sealing member includes: A gap of 1 mm to 5 mm is formed between the projection type display device and the light modulation device.