JP2001042435A - Projector device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the cooling performance of the optical system of a liquid crystal projector. SOLUTION: The optical system unit of the liquid crystal projector is constituted by incorporating at least liquid crystal light valves 6a and 6c and polarizing plates 30a and 30c. The optical system unit is hermetically sealed by an optical unit case 4, a cover 21, an upper cover 22a, a lower cover 22b and the like. By coupling the optical system unit and a cooling part 9 by hoses 11a, 11b and 11c, a hermetically sealed duct-like space is formed. By a fan 10, air in the duct is circulated in the direction of an arrow A. In the midst of this circulation, the valves 6a and 6c and the plates 30a and 30c are deprived of heat and cooled by the air. Then, the heat is radiated outside through ventilation holes 12 formed at a housing 7 through the heat radiating fins 36 of the cooling part 9. By providing the hoses 11a, 11b and 11c with heat radiating fin 36a, the radiation of the heat is helped. By arranging a heat conductive plate 34a at one part of the cooling part 9 and connecting it to a heat conductive plate 34b arranged outside by a heat pipe 35, the radiating quantity of heat is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector, and more particularly to a liquid crystal projector having a cooling device for effectively cooling optical components such as a liquid crystal light valve.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal light valve corresponding to the primary colors of red, green and blue is provided, and each light valve is controlled by an individual image signal to generate a three-color image, which is synthesized by a dichroic prism or the like to produce a color image. 2. Description of the Related Art A liquid crystal projector that performs enlarged projection as an image is known. In these projectors, a discharge lamp such as a metal halide lamp with high power consumption is often used as a light source. Accordingly, there is a growing interest in cooling devices for suppressing a rise in temperature due to heat applied to optical components such as a liquid crystal light valve through which a light beam passes.

As an example, a method for cooling an optical component of a liquid crystal projector has been proposed in documents such as JP-A-7-152009 and JP-A-10-254062. In the former, three light valves are placed in a circulation path in which cooling air is sealed, air in the circulation path is circulated by a fan, and heat is radiated to the outside of the path by an electronic cooling device arranged in the path. The latter seals the optical unit, arranges a duct section and connects them, forms a circulation path through which the cooling air inside can cycle, and circulates the air in the circulation path by a fan in the path, The heat transfer plate, which is located at one corner of the section and has one end reaching the outside of the duct section, carries heat out of the duct. A heat pipe or the like may be provided at one end of the heat conduction plate outside the duct, which is characterized in that heat is efficiently dissipated.

Although the details of the liquid crystal projector will be described later, the latter configuration will be briefly described with reference to FIG. FIG.
4A is a perspective view showing the appearance of the optical unit of the liquid crystal projector, and FIG. 4B is a schematic diagram showing the outline of the optical unit with the lid 21 removed. An optical unit case 4 containing the optical unit 3 is mounted on the substrate 1,
It is covered with a lid 21. A drive circuit 8 for supplying an image signal to the liquid crystal light valve is disposed thereon. In order to cool the liquid crystal light valve etc.
a and the lower cover 22b are attached to the upper and lower sides of the optical unit case 4, and the upper and lower covers 22a and 22b and the optical unit case 4 form a circulation path through which the cooling air makes a round.

[0005] The configuration and function of the optical system as a liquid crystal projector will be described in detail later. As shown in FIG. 4B, a light beam emitted from the light source 2 is separated into three primary colors of RGB (red, blue, and green) by dichroic mirrors 27a and 27b, and the polarizing plates 30a, 30b, and 3 are separated.
0c. These polarized monochromatic lights enter the liquid crystal light valves 6a, 6b, 6c. The liquid crystal light valves 6a, 6b, 6c are supplied with a drive signal from the drive circuit 8 and each display an RGB image.
An image of a single monochromatic light is obtained. The three luminous fluxes enter the combining prism 5 and are combined in color, enlarged by the projection lens 32, and projected on a screen (not shown).

FIG. 5A is a sectional view taken along a cutting line AA in FIG.
It is sectional drawing of 3 vicinity. When the optical unit case 4 is fixed to the upper cover 22a and the lower cover 22b, an ascending flow path of air for cooling the liquid crystal light valve and other components around the synthetic prism 5 and a duct portion 33 descending for heat radiation are formed. With the inside of the upper cover 22a and the lower cover 22b as a communication path, the ascending flow path and the descending duct portion 33 are connected to form a circulation path for the cooling air. This circulation path is sealed to the outside. Lower cover 22b
, The fan 1 disposed immediately below the synthetic prism 5
When 0 rotates, the air in the circulation path circulates as indicated by the arrow in the figure. In particular, the heat of the air that has cooled and cooled the condenser lenses 29a and 29c of the optical system focusing on the liquid crystal light valves 6a and 6c and the polarizing plates 30a and 30c, etc., is disposed in the lower right corner of the duct portion 33. The heat is dissipated to the outside of the circulation path via the heat conduction plate 34.

A first example of the invention showing the above-mentioned technique is shown in FIG. In this example, the configuration of the optical system is different from that of FIG. 4B. Instead of the combining prism 5, three monochromatic lights passing through the liquid crystal light valves 6a, 6b, and 6c are combined by a plurality of color combining dichroic mirrors. are doing. 4 (b) and the liquid crystal light valves 6a, 6
Since the arrangement of b and 6c is different, a circulation path of the cooling air is formed in parallel with the light passing plane, and the air sealed in the duct is circulated by the fan 10 in the direction of the arrow, and the liquid crystal light valve is mainly used. Cool the optical system. The heat of the air in the heated circulation path is radiated to the outside of the circulation path via the electronic cooling device 37.

In both of the above-described inventions, the optical system is disposed in a closed circulation path, and the heat of the optical system is dissipated outside the circulation path using the air in the closed circulation path as a medium. It is considered to be the same technical idea in that the use of a closed circulation path prevents the entry of external dust into the optical system and does not emit noise from the fans in the circulation path to the outside.

[0009]

Recently, these projector apparatuses have a remarkable tendency to increase the size of a projection screen and increase the brightness of an image, but all of them increase the output of a light source and reduce the amount of heat flowing into an optical system. The amount of heat that cools it and dissipates it outside the optical unit is also increasing. However, the amount of the sealed cooling air is limited, and there is a problem that the cooling efficiency is reduced when the amount of cooling heat is increased for a certain amount of air. In addition, although the amount of heat dissipated to the outside by the heat radiating portion also increases, in the conventional example, since the heat radiating portion to the outside of the heat conductive plate or the electronic cooling device is disposed very close to the optical system, heat is radiated from the circulation path. There is also a problem that the optical system is heated by heat.

[0010]

In order to solve this problem, the present invention irradiates light emitted from a light source onto a video display panel, and magnifies and projects the transmitted light of the video display panel with a projection lens to form an image on a screen. In a projector device that displays
An optical unit including at least an image display plate and having a sealed structure except for two connection holes, and a cooling unit;
A cooling unit having a sealing structure except for the connecting holes, a first connecting hole provided in the optical unit, and a first connecting hole provided in the cooling unit. An optical unit, comprising: a first ventilation path, a second connection hole provided in the optical unit, and a second ventilation path connecting the second connection hole provided in the cooling unit. A cooling circuit, a first ventilation path, and a second ventilation path form a sealed circulation path, and at least one fan that blows air in the circulation path in one direction is provided in the circulation path. Provided is a projector device.

Further, in the present invention, a fan is provided in the vicinity of the windward side of the image display panel, and the image display panel is cooled by blowing the fan. And a projector device having a plurality of fins implanted outside the projector. Further, the cooling means is formed in a plate shape with a heat conductive material, is provided on one surface of the cooling unit, one surface of the cooling unit faces the inside of the cooling unit, and another surface of the cooling unit is another surface of the cooling unit. Provided is a projector device exposed on an outer surface. Further, the present invention also provides a projector device in which one end of a heat pipe is fixed to another surface of the cooling means exposed on the outer surface of the cooling part of the cooling means, and a radiating fin is provided at the other end of the heat pipe.

Further, the number of fans in the circulation path is not one,
The first ventilation path or the second ventilation path in the middle of the second ventilation path
A projector device provided with a fan, a first ventilation path,
The second ventilation passage is formed of a thin aluminum material in a bellows shape, and the first ventilation passage and / or the second ventilation passage is formed of a thermally conductive material. Provided with a plurality of fins.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One example of a liquid crystal projector according to an embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 1A is a center sectional view of the liquid crystal projector taken along the line AA in FIG. 1B, and FIG. 1B is a front projection view of the liquid crystal projector. The optical unit 3 and the like are exposed and drawn. A light source 2 and an optical unit 3 are arranged on a substrate 1 fixed to a chassis 7b housed in a lower part of a housing 7, and a cooling unit 9 is connected to the optical unit 3 via a hose 11a. The image projected from the optical unit 3 is reflected by the rear mirror 15 and is enlarged and projected on the screen 16. Since the optical path between the optical unit and the screen is long, the rear mirror 15 is used so that the housing can be small. In the projector shown in FIG. 1, since the viewer views the image projected on the screen from the right side of FIG. 1A, this format is called a rear projection type projector. In the future, the same parts will be denoted by the same reference numerals in all drawings, and description thereof may be omitted.

An example of an optical system of a projector using a liquid crystal light valve as an image display panel will be described with reference to FIG. FIG. 1C schematically illustrates the inside of the optical unit 3 to show the arrangement of the optical system. A light beam emitted from the light source 2 in which a metal halide lamp or the like is covered with a reflecting mirror has a cut filter 23 for blocking ultraviolet and infrared rays,
The light passes through the polarization conversion element 20 and the lens arrays 24a and 24b, and mainly the visible light component enters the dichroic mirror 27a. The R light is separated and reflected by the dichroic mirror 27a, and the reflection mirror 28a, the condenser lens 29a, and the polarizing plate 30
The light passes through the liquid crystal light valve 6a for red through a.

On the other hand, the light beam that has passed through the dichroic mirror 27a is separated into a green light beam and a blue light by the dichroic mirror 27b.
b, liquid crystal light valve 6b for green via polarizing plate 30b
Pass through. The blue light transmitted through the dichroic mirror 27b is transmitted through a relay lens 31a, a reflection mirror 28b, a relay lens 31b, a reflection mirror 28c, a condenser lens 29c,
The light passes through the blue liquid crystal light valve 6c via the polarizing plate 30c. The three colors of light that have passed through the liquid crystal light valves 6a, 6b, 6c are combined in color by the combining prism 5, and the projection lens 3
2, the light is reflected by a rear-view mirror as shown in FIG.

Next, a method of cooling the optical unit 3 of the projector according to the present invention will be described with reference to FIGS. FIG. 2 shows the external appearance of the optical unit 3, the cooling unit 9 for cooling the optical unit 3, and the hoses 11a, 11b, 11c connecting the optical unit 3 and the like. FIG. 2 (a) is a perspective view thereof, and FIG.
2C shows a plan view seen from above, and FIG. 2C shows a front view seen from the projection lens 32 side. This is shown as a cross section of the hoses 11a, 11b, 11c in FIG.
FIG. 3A is a cross-sectional view taken along the line BB of FIG. 2B, and is cut at the center of the liquid crystal light valve 6a for red, the synthetic prism 5, and the liquid crystal light valve 6c for blue, and the projection lens 32 side. It is seen from. In this figure, the light valve 6b for green, the condenser lens 29b, the polarizing plate 30b
Although not shown because it is located on the back surface of the combining prism 5, it is located at the same position as the other red and blue components around the combining prism 5. FIG. 3C is a cross-sectional view cut at the same value as that of FIG. 3A, and is configured by the same members as those of FIG. FIG. 3B shows the hoses 11a, 1
The radiation fins provided in 1b and 11c are shown as schematic diagrams.

The optical components constituting the optical unit 3 are accommodated in the optical unit case 4 and the cover 21, the upper cover 22a and the lower cover 22b are fixed to the optical unit case 4, so that the cover hose openings 13a and 13b are formed. It is completely sealed except for the opening. The upper cover 22a is viewed from above, and the lower cover 22b is viewed from below. The liquid crystal light valves 6a, 6b and 6c centering on the synthetic prism 5 and the polarizing plate 3
0a, 30b, 30c, etc., are arranged at positions covering them from above and below. A drive circuit 8 for driving the liquid crystal light valve 6 is mounted on the lid 21, and is connected to the liquid crystal light valve 6. In order to finely move the liquid crystal light valve 6 to perform registration adjustment (image overlay adjustment),
The upper cover 22a is detachable from the optical unit case 4.

As will be described in detail later, the cooling unit 9 for radiating heat from the optical unit 3 includes a cooling hose port 1 opened to the outside.
4a and the cooling hose port 14b are sealed except for the case. In order to dispose the cooling unit 9 away from the optical unit 3, the hose 1 serving as a ventilation path is connected to the optical unit 3 and the cooling unit 9.
1a, 11b and 11c are used. Hose ports for connecting these hoses are provided at required places. That is, the cover hose port 13 is provided in the upper cover 22a.
a, a cover hose port 13b is formed in the lower cover 22b, and a cooling hose port 14b is formed in the upper part of the cooling unit 9.
a, a cooling hose port 14b is formed in the lower part. These hose ports have openings at the ends, and hoses 11a,
By inserting and connecting 11b and 11c, a sealed state is provided to the outside. Therefore, by inserting the hoses 11a, 11b, and 11c into the hose openings of the optical unit 3 and the cooling unit 9, the internal air can be removed by the optical unit 3, the cooling unit 9, and the hoses 11a, 11b, and 11c connected thereto. A circuit is formed, and the internal air is sealed from the outside. Although the function will be described later, the fan 11a may be inserted between the hoses 11b and 11c in some cases, and this connection portion is also sealed from the outside.

As shown in the cross-sectional view of FIG. 3A, the fan 10 is disposed in the lower cover 22b and blows air from immediately below the synthetic prism 5 upward. The cooling air flows in the direction of the arrow in the optical unit case 4, the upper cover 22a, and the lower cover 22.
b, the liquid crystal light valves 6a, 6b, and 6c heated by the illumination light of the light source 2 up the duct-like air path.
Hose connected to the upper cover 22a after depriving the optical components such as the polarizers 30a, 30b, and 30c of heat and cooling.
It passes through the inside of 1a and reaches the cooling unit 9. Since the blower fan is installed in a closed circulation path, the operating noise of the fan is less likely to leak outside.

The cooling unit 9 is made of, for example, a thin box of metal or the like and has a rectangular box shape. A plurality of radiating fins 36 serving as cooling means are provided on an outer wall of the cooling unit 9. The cooling fins 36 of the cooling unit 9 are placed close to the inner wall of the housing 7 in which many ventilation holes 12 are opened. Therefore, the warmed air guided into the cooling unit 9 emits heat to the outside air via the cooling fins 36. The air cooled by heat radiation is supplied to the lower hose 1
The air path is raised again by the fan 10 through 1b and 11c to cool the liquid crystal light valve 6 and the polarizing plate 30. Thus, the optical unit 3, the cooling unit 9, the hose 11a,
The air in the enclosed space formed by 11b and 11c is urged by the fan 10 to circulate. During this circulation, the air sealed in the duct cools at least the liquid crystal light valve 6 and the polarizing plate 30 of the optical system to take heat, and the heat is dissipated by the cooling unit 9 to repeatedly change the temperature. Note that the upper cover 22a is formed in a shape with as little air resistance as possible, such as by providing an appropriate inclination in order to flow air smoothly.

Since the cooling unit 9 is separated from the optical unit 3, there is little restriction on the size of the cooling unit, and the shape of the cooling unit is changed according to the design requirement of the housing. Can also be configured. Cooling unit 9
Can be increased irrespective of the optical unit 3, so that the amount of air required for cooling can be secured. Hose 11
The internal volumes of a, 11b, and 11c are also added to the volumes of the optical unit 3 and the cooling unit 9, and the amount of air usable for cooling further increases.

If the hoses connecting the optical unit 3 and the cooling unit 9 have appropriate flexibility, the housing 7
Can respond to a slight change in size. Further, the hose 11
If the lengths of a, 11b and 11c are changed, the optical unit 3
And the cooling unit 9 can be arranged at an arbitrary distance,
The same optical unit 3 and the cooler 9 can accommodate various sizes of housings having different sizes.

When the hose is long and the wind pressure is insufficient with the fan 10 alone, for example, an auxiliary fan 10a can be inserted between the hose 11b and the hose 11c. If the air cooled by the cooling unit 9 is sucked and accelerated by the fan 10a and sent to the suction side of the fan 10, the wind speed for cooling the optical components increases, and the air volume per unit time also increases. That is, the amount of heat absorbed per unit time from the optical component also increases. If the auxiliary fan 10a is used, the fan 10 can be used without change, and the optical unit 3 does not need to be changed.

As long as the hoses 11a, 11b and 11c have a certain degree of flexibility, the materials and shapes of the hoses 11a, 11b and 11c can be changed in various ways. For example, a flexible rubber or plastic material, a thin metal pipe formed in a bellows shape and having added flexibility can be used. As an example, if the hose is formed of a thin aluminum pipe in a bellows shape, the hose has flexibility and heat is efficiently radiated. As shown in FIG. 3 (b), uneven radiating fins may be formed on the hoses 11a, 11b, 11c to radiate heat even at the hose portion. In particular, a large heat radiation effect can be expected with the hose 11a that guides high-temperature air. As described above, the use of the flexible hose allows the cooling unit 9 to be mounted at a position sufficiently distant from the optical unit 3, and the mounting position and posture of the cooling unit 9 can be easily adjusted.

Further, as shown in FIG.
A heat conductive plate 34a is provided on a part of the wall of the heat conductive plate 34a.
Is exposed inside the cooling unit 9, and the other surface is exposed to the cooling unit 9.
It is also possible to increase the heat radiation of the cooling unit 9 by connecting one end of the heat pipe 35 to the other surface of the heat conductive plate 34a and connecting the heat conductive plate 34b to the other end thereof. it can. In this figure, since the components other than the cooling unit 9 are completely the same as those in FIG. 3A, the reference numerals on the left side of the hoses 11a and 11b are omitted.

Although the rear projection type projector has been described as an example of the entire apparatus and the three-panel type liquid crystal projector has been described as an example of the optical system, the present invention does not need to be limited to these types. The present invention is also applicable to other projector devices and general optical devices that receive a large amount of heat from a light source.

[0027]

According to the present invention, since the sealed optical unit and the cooling unit are connected by the hose, the cooling unit can be freely arranged at a position away from the optical unit. Since the cooling section is independent, an arbitrary volume can be obtained, and the total amount of cooling air increases, so that a large amount of heat can be efficiently removed. The volume of the hose connecting them also helps to increase the amount of air. Also, since the optical unit and cooling unit are separated,
The cooling unit can be arranged at a position where heat can be easily dissipated, and heat can be easily dissipated from the housing to the outside. In addition, there is an effect that the optical unit is less likely to be reheated by the heat radiated from the cooling unit.

According to the sixth aspect, even if the size of the housing is large and the length of the hose is long, and the capacity of the fan is insufficient, an auxiliary fan is inserted in the middle of the hose to increase the air volume so that the optical unit is the same. Has the advantage that it can be used. Claim 7
According to this method, heat dissipation can be assisted by using a bellows-shaped hose made of thin aluminum, and flexibility can be ensured, so that the condition is good.

Further, one type of optical unit and cooling unit can be applied to various housings, and a large number of products can be covered by a small number of types of optical units, thereby reducing inventory. Further, since the optical unit and the cooling unit are separated, the optical unit can be reduced in size, and labor saving in the assembling process and the after-sales service process can be achieved.

[Brief description of the drawings]

FIG. 1 is an external view of a rear projection type projector, which is an example of an embodiment of the present invention, and a schematic diagram illustrating a configuration of an optical system.

FIGS. 2A and 2B are a perspective view and a projection view illustrating an appearance of an optical system and a heat radiating unit of the present invention.

FIG. 3 is a cross-sectional view illustrating a structure of a heat radiating unit of the present invention.

FIG. 4 is a perspective view showing an appearance of an optical system of a conventional projector, and a schematic diagram for explaining a configuration of the optical system.

FIG. 5 is an explanatory view of a heat dissipating part of a conventional example.

[Explanation of symbols]

1 substrate, 2 light sources, 3 optical units, 4 optical unit cases, 5 synthetic prisms, 6a R liquid crystal light valve for R, 6b G liquid crystal light valve for green, 6c B
Liquid crystal light valve for blue, 7 housing, 7a panel, 7
b chassis, 8 drive circuit, 9, 9a cooling unit, 1
0, 10a fan, 11a, 11b, 11c hose, 12 vent, 13a, 13b cover hose,
14a, 14b cooling hose outlet, 15 rear mirror, 1
6 screen, 20 polarization conversion element, 21 lid, 22
a upper cover, 22b lower cover, 23 cut filter, 24a, 24b lens array, 26 condenser lens, 27a dichroic mirror, 27b dichroic mirror, 28a, 28b, 28c reflection mirror,
29a, 29b, 29c Condensing lens, 30a, 30
b, 30c polarizing plate, 31a, 31b relay lens,
32 projection lens, 33 duct, 34a, 34b
Heat conduction plate, 35 heat pipe, 36, 36a radiation fin, 37 electronic cooling device, 38 dichroic mirror for color synthesis

Claims (8)

[Claims] 1. A projector device that irradiates light emitted from a light source onto an image display plate and enlarges and projects transmitted light of the image display plate with a projection lens to display an image on a screen, including at least the image display plate. An optical unit having a sealed structure except for the two connecting holes, a cooling unit having a cooling means having a cooling structure except for the two connecting holes, and a cooling unit provided in the optical unit. A first connection hole, a first ventilation path connecting the first connection hole provided in the cooling unit, and a second connection hole provided in the optical unit; And a second ventilation path that connects a second connection hole provided in the cooling unit. The optical unit, the cooling unit, the first ventilation path, and the second ventilation path Forming a sealed circulation path in the circulation path, Blowing the air in the ring path in one direction, a projector apparatus characterized by comprising at least one fan. 2. The projector device according to claim 1, wherein the fan is provided near the windward side of the image display panel, and cools the image display panel by blowing air from the fan. 3. The projector device according to claim 1, wherein the cooling unit is a plurality of fins planted outside one surface of the cooling unit. 4. The cooling means is formed in a plate shape with a heat conductive material, is provided on one surface of the cooling part, one surface of the cooling means faces the inside of the cooling part, and The projector device according to claim 1, wherein one surface is exposed to an outer surface of the cooling unit. 5. The heat pipe according to claim 1, wherein one end of the heat pipe is fixed to the other surface of the cooling means exposed on the outer surface of the cooling unit, and a radiating fin is provided at the other end of the heat pipe. 5. The projector device according to 4. 6. The projector according to claim 2, wherein a second fan is provided in the first ventilation path or in the middle of the second ventilation path. 7. The projector device according to claim 1, wherein the first ventilation path and the second ventilation path are formed of a thin aluminum material in a bellows shape. 8. The method according to claim 1, wherein the first ventilation path and / or the second ventilation path are formed of a heat conductive material, and a plurality of fins are implanted on an outer surface. Item 2. The projector device according to item 1.