JP2003262921A - Projection video display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projection video display device which makes improvement in exhaust efficiency and sufficient light shielding of unnecessary light compatible. <P>SOLUTION: A fan device 6 consists of a first fan 6a, a second fan 6b and a motor 6c. The first fan 6a and the second fan 6b are both fixed to one revolving shaft of the motor 6c and rotate one body. The first fan 6a and the second fan 6b consist of four-blade configurations respectively provided with four blades at 90° intervals. The second fan 6b is fixed with the four blades in the state of shifting the blades with respect to the blades of the first fan 6b at 45°. As a result, the first fan 6a and the second fan 6b rotate as one body to shield the light by positioning their blades at the points where the other blades do not exist. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type image display device such as a liquid crystal projector.

[0002]

2. Description of the Related Art FIG. 3 is a diagram showing an optical system of a three-plate color liquid crystal projector. The light emitting section 2 of the light source 1 is composed of an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp, etc., and its irradiation light is emitted as parallel light by the parabolic reflector 3 and guided to the integrator lens 4.

The integrator lens 4 is composed of a pair of lens groups 4a, 4a, and each lens pair outputs the light emitted from the light source 1 to the liquid crystal light valves 31, 32, 3.
It is designed to lead to the entire surface of 3. The light that has passed through the integrator lens 4 is unified into, for example, S-polarized light by the polarization conversion device 5, and then is guided to the first dichroic mirror 8.

The first dichroic mirror 8 transmits light in the red wavelength band and reflects light in the cyan (green + blue) wavelength band. The light in the red wavelength band that has passed through the first dichroic mirror 8 is reflected by the total reflection mirror 9 and the optical path thereof is changed. The red light reflected by the total reflection mirror 9 is optically modulated by passing through the condenser lens 10 and the transmissive liquid crystal light valve 31 for red light. On the other hand, the light in the cyan wavelength band reflected by the first dichroic mirror 8 is guided to the second dichroic mirror 11.

The second dichroic mirror 11 transmits light in the blue wavelength band and reflects light in the green wavelength band. The light in the green wavelength band reflected by the second dichroic mirror 11 is guided through the condenser lens 12 to the transmissive liquid crystal light valve 32 for green light, and transmitted therethrough to be optically modulated. Further, the light in the blue wavelength band transmitted through the second dichroic mirror 11 is reflected by the total reflection mirror 1.
4, 16 and relay lenses 13 and 15, and condenser lens 17, and then a transmission type liquid crystal light valve 3 for blue light.
The light is modulated by being guided to No. 3 and transmitted therethrough.

The respective liquid crystal light valves 31, 32, 33 are
Incident side polarization plates 31a, 32a, 33a, panel parts 31b, 32b, 33b formed by enclosing a liquid crystal between a pair of glass substrates (on which pixel electrodes and alignment films are formed), and emission side polarization plates 31c, 32c and 33c. Also,
Each liquid crystal light valve 31, 32, 33 is provided with a microlens corresponding to each pixel. The modulated light (each color image light) modulated by passing through the liquid crystal light valves 31, 32, 33 is combined by the dichroic prism 18 to become a color image light. The color image light is enlarged and projected by the projection lens 19 and projected and displayed on the screen 20.

FIG. 4 is a plan view showing details of the illumination optical system in the projection type image display device. An opening 7a for exhaust is formed on the back side of the light source 1 in a casing 7 that supports and surrounds the light source 1, the integrator lens 4, and the like. An exhaust fan device 51 is provided in the opening 7a. This exhaust fan device 51 is shown in FIG.
As shown in (b), fan 51a and motor 51b
The heat generated from the light source 1 and the like is discharged to the outside of the machine. Further, the opening 7a is provided with a light blocking plate 52 for blocking unnecessary light leaking from the back side of the light source 1. The light shielding plate 52 is composed of a first slit 52a and a second slit 52b, and has a light shielding property and secures a gap necessary for exhaust.

[0008]

However, if an attempt is made to obtain a sufficient light-shielding property in the light-shielding plate 52, there is a drawback in that the gap becomes narrower and the resistance to exhaust increases, so that the exhaust efficiency decreases.

In view of the above circumstances, it is an object of the present invention to provide a projection type image display device capable of achieving both improvement of exhaust efficiency and sufficient blocking of unnecessary light.

[0010]

In order to solve the above-mentioned problems, a projection-type image display device according to the present invention is a projection-type image display device in which light emitted from a light source is modulated by a light valve and projected. A fan device composed of multiple fans is provided in the ventilation opening formed in the device housing, and each fan rotates while forming a light-shielding state with its blade located at a non-existing portion of the other fan. It is characterized by being configured in.

With the above construction, since each fan rotates while forming its light-shielding state with its blade located at the blade-free portion of the other fan, unnecessary light passes through the blade-free portion. It is possible to prevent getting out of the plane.
Further, since it is not necessary to provide the light shielding plate composed of the slit, the exhaust efficiency can be improved. Further, improvement in exhaust efficiency by rotating a plurality of fans can be expected.

The ventilation opening may be an exhaust port formed on the back side of the light source.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A projection type image display apparatus according to an embodiment of the present invention will be described below with reference to FIGS. In this embodiment, a liquid crystal projector using three transmissive liquid crystal display panels is used, and its image generation optical system is the same as that of the liquid crystal projector of FIG. 3 used in the description of the conventional example. The description of the image generation optical system is omitted, and the illumination optical system will be mainly described.

FIG. 1 is a plan view showing details of an illumination optical system in a liquid crystal projector. The housing 7 includes the light source 1,
It is configured to support and surround the integrator lens 4, the polarization conversion device 5, and the like. An opening 7a for exhaust is formed in the housing 7 on the back side of the light source 1. A fan device 6 is provided in the opening 7a, and heat generated from the light source 1 and the like is discharged to the outside of the machine.

As shown in FIGS. 2 (a) and 2 (b), the fan unit 6 is composed of a first fan 6a, a second fan 6b, and a motor 6c. Both the first fan 6a and the second fan 6b are fixed to one rotating shaft of the motor 6c so that they can rotate together. First fan 6a and second fan 6b
Has a four-blade configuration including four blades at 90 ° intervals, and the second fan 6b shifts the four blades by 45 ° with respect to the four blades of the first fan 6a. It is fixed in the opened state. The center angle of each blade is 9
It has a shape corresponding to a substantially fan shape exceeding 0 °. As a result, the first fan 6a and the second fan 6b have their blades located at positions where the blades do not exist, and the blades of the first fan 6a and the blades of the second fan 6b partially overlap with each other (contact is It does not rotate).

With the above structure, the blades of the first fan 6a and the second fan 6b rotate while forming the light-shielding state at the positions where the blades do not exist, so that unnecessary light is emitted from the positions where the blades do not exist. Can be prevented from passing through and exiting the aircraft. In particular, in this embodiment, the first fan 6
Since the blade of a and the blade of the second fan 6b are partially overlapped with each other, the light can be shielded more reliably. Further, since it is not necessary to provide the light shielding plate (slit) in the conventional configuration,
Exhaust efficiency can be improved. Furthermore, two fans 6a
It is expected that the exhaust efficiency will be improved by rotating 6b.

In the above configuration example, four fans 6a and 6b are provided.
Although the blade is a single blade, a two-blade configuration, a three-blade configuration, or the like may be used. In the case of a two-blade configuration, each blade has a shape corresponding to a substantially fan shape with a central angle exceeding 90 °,
One fan is fixed with its two blades shifted by 90 ° with respect to the blades of the other fan, and in the case of a three-blade configuration, each blade has a fan shape with a central angle exceeding 60 °. It is sufficient that one fan is fixed with its three blades shifted by 60 ° with respect to the blades of the other fan.

The blade of the fan does not have to have a shape corresponding to the fan shape. For example, even if the blade has a substantially quadrangular shape, the blade having the substantially quadrangular shape is located at a nonexistent portion of another fan. It may be any one that rotates while forming a light blocking state. In addition, each fan does not have to have the same blade shape, and for example, one fan blade may have a fan shape and the other fan blade may have a quadrangular shape.

Further, in the above example, the fan device including the fans 6a and 6b is shown, but the fan device is provided with three or more fans, and the blades of each fan are located at the blade-free portions of the other fans, and the light shielding state is provided. You may comprise so that it may rotate, forming.

Further, in the above example, the fans 6a and 6b are rotated by one motor 6c, but the fans 6a and 6b may be rotated by separate motors synchronously.

In the above example, the fan device 6 is arranged on the back side of the light source 1 to evacuate the air. However, it is in the vicinity of the optical element that is heated and where light leakage may occur. The fan device 6 may be disposed in the.

In the above example, the image generation optical system using three transmissive liquid crystal display panels is shown, but the invention is not limited to such an image generation optical system, and another image generation optical system may be used. It can also be applied when used.

[0023]

As described above, according to the present invention, each fan rotates while forming its light-shielding state with its blades located at the blade-free portions of the other fans. It is possible to prevent unnecessary light from passing through and exiting the aircraft. Further, since it is not necessary to provide the light shielding plate composed of the slit, the exhaust efficiency can be improved.
Further, there is an effect that the exhaust efficiency can be expected to be improved by rotating a plurality of fans.

[Brief description of drawings]

FIG. 1 is a diagram showing an illumination optical system of a projection-type image display device according to an embodiment of the present invention.

2 (a) is a plan view of a fan device provided in the illumination optical system of FIG. 1, and FIG. 2 (b) is a front view thereof.

FIG. 3 is a plan view showing an optical system of a conventional projection-type image display device.

FIG. 4 is a diagram showing an illumination optical system in the projection-type image display device of FIG.

5 (a) is a plan view of a fan device provided in the illumination optical system of FIG. 4, and FIG. 5 (b) is a front view thereof.

[Explanation of symbols]

1 light source 6 fan device 6a First fan 6b Second fan 6c motor

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // F21Y 101: 00 F21M 7/00 LF term (reference) 2H088 EA12 EA68 HA13 HA14 HA24 HA28 MA20 2K103 AA01 AA05 AA11 AA16 CA08 DA02 DA06 DA10 DA20 3K014 AA01 LA01 MA02 MA05 MA08 3K042 AA01 AC06 BA08 CB16 CC04

Claims (2)

[Claims] 1. A projection-type image display device for modulating and projecting light emitted from a light source by a light valve, wherein a ventilation device formed in a device housing is provided with a fan device including a plurality of fans. A projection-type image display device, wherein each fan is configured such that its blade is located at a position where the other fan does not exist and rotates while forming a light shielding state. 2. The projection display apparatus according to claim 1, wherein the ventilation opening is an exhaust port formed on the back side of the light source.