JP2002214596A - Liquid cooling unit and liquid crystal projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid cooling unit capable of efficiently cooling an outgoing side polarizing plate by a simple structure. SOLUTION: A solution 41 for liquid cooling is enclosed between two transparent substrates 27, 31 and an outgoing side polarizing plate 23 is stuck to the incident side substrate 27. A projecting bar part 55 is formed along the four inside faces of the opening 53 of a metallic frame 51 which supports the substrates 27, 31 and the substrate 27 is attached to side faces 55c of the projecting bar part 55 by way of packing 29. The substrate 31 is kept away from the projecting bar part 55 and attached by way of packing 33. The packing 29 has inside faces which overlap the front edge faces 55a of the projecting bar part 55 of the metallic frame 51, so that a stepped part 56 comprising the front edge faces 55a and side faces 55b of the projecting bar part 55 comes in contact with the solution 41 for liquid cooling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for efficiently cooling an exit-side polarizing plate of a liquid crystal projector.

[0002]

2. Description of the Related Art FIG. 7 shows a known optical system in a liquid crystal projector. LCD projector 100
The light source 103 includes, for example, a high-intensity lamp such as a metal halide lamp, the reflecting mirror 105 that reflects light from the light source 103, the illuminance distribution of the reflected light from the reflecting mirror is uniform, and the polarization directions are uniform. And a dichroic mirror 109a, 109b and a reflection mirror 110. The light beam W emitted from the illumination optical system 107 is converted into red, green, and blue light beams R, G, respectively. , B and a color light separation optical system 109 for guiding the red light beam R and the green light beam G to the corresponding liquid crystal panels, respectively. Optical system 111 that guides each color light beam according to given image information, and synthesizes each modulated color light beam. It includes a rhythm 15, a projection lens 117 for enlarging and projecting the synthesized light flux on the projection plane 116.

The light modulator 113 has a liquid crystal panel 119 for modulating each color light beam in accordance with given image information, an incident side polarizing plate 121 on a light incident side, and an output side polarizing plate on a light exit side. Plates 123 are arranged respectively. The incident side polarizing plate 121 aligns the polarization directions of the respective color light beams separated by the color light separation optical system 109. Here, the incident side polarizing plate 121 is adapted to align the light beams into S-polarized light. Only the P-polarized light component of the modulated light is transmitted from the output-side polarizing plate 123.

Although the structure shown in FIG. 7 is a so-called three-panel type using three liquid crystal panels corresponding to each color of RGB, the same applies to a single-panel type using one liquid crystal panel. Is provided.

[0005] In the light modulator 113 configured as described above, the incident side polarizing plate 121 and the outgoing side polarizing plate 123 are
Since each passes only one polarized light and blocks (absorbs) the other polarized light, heat is easily generated. In particular, the output-side polarizing plate 123 is provided in accordance with the modulation of the liquid crystal panel 119.
There is a problem that the temperature rise is remarkable because all of the incident light may be absorbed.

Therefore, various cooling methods have been proposed for suppressing a rise in the temperature of the exit-side polarizing plate 123. The cooling methods of the air cooling type and the liquid cooling type will be described below with reference to the drawings.

FIG. 8 shows an example of a cooling system using an air cooling system. In this air cooling system, the incident side polarizing plate 121 is used.
And the emission-side polarizing plate 123 are respectively connected to the transparent substrate 1 for heat dissipation.
25 and 127, and the incident side polarizing plate 121,
The liquid crystal panel 119 and the output-side polarizing plate 123 are arranged separately from each other, and are cooled by flowing air with a cooling fan (not shown) between them.

FIG. 9 shows an example of a cooling system using a liquid cooling system. FIG. 10 is an enlarged sectional view of the liquid cooling unit shown in FIG. This liquid-cooled type is the air-cooled type shown in FIG. 8 in which the output side polarizing plate 123 is unitized together with its cooling structure. 127, a transparent substrate 129 is disposed opposite to the transparent substrate 127, and a liquid cooling solution 131 is sealed therebetween. More specifically, a flat plate-shaped metal frame having an opening in the center is provided. 135, a ridge 137 is formed over the entire length on the inner periphery of the four sides of the opening, and the transparent substrate 127 and the transparent substrate 129 are formed on both left and right sides of the ridge 137 with the liquid cooling solution 131. A plate-like packing 139 for preventing leakage is interposed therebetween, and a pair of frame covers 143 are disposed on both sides of the packing 139 so as to face each other with a packing 141 having the same configuration as the packing 139 interposed therebetween. Between Mukaba 143 with the mounting screws 145 is obtained by unitizing bonded integrally.

The frame cover 143 has an opening through which light passes, and its inner peripheral surface is formed of a metal frame 135.
Are formed so as to be substantially flush with the tip end surface 137a of the ridge portion 137. Similarly, the packing 139 has an inner peripheral surface formed on the distal end surface 13 of the ridge 137 of the metal frame 135.
The space for enclosing the liquid cooling solution 131 is formed in a rectangular shape.

[0010] The liquid cooling unit 133 thus configured
, The heat of the output side polarizing plate 123 is
While being radiated, the liquid cooling solution 131 is transmitted to the liquid cooling solution 131 via the transparent substrate 127, and the heat transmitted to the liquid cooling solution 131 is transmitted to the metal frame 135 by convection, and is released to the outside by a cooling fan (not shown). It is supposed to be.

[0011]

However, even with the above-described cooling method, a satisfactory cooling effect cannot be obtained due to the high output of the light source accompanying the recent increase in brightness of the projector. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide a liquid cooling unit and a liquid crystal projector capable of efficiently cooling an output side polarizing plate with a simple configuration.

[0013]

A liquid cooling unit according to one embodiment of the present invention includes a liquid cooling solution sealed between two transparent substrates, and a transparent substrate on an incident side of the two transparent substrates. The liquid-cooling unit has an opening on the outer surface of the liquid-cooling unit, which is provided with an exit-side polarizing plate through which the light emitted from the liquid crystal panel passes, and has an opening. And a metal frame having a ridge portion formed thereon, and one of the two transparent substrates is mounted on the side surface of the ridge portion via the first packing from one surface side of the metal frame. At the same time, from the other surface side of the metal frame, the other transparent substrate is separated from the ridge and is mounted via the second packing, and the first packing is substantially the same as the tip surface of the ridge of the metal frame. It is configured to have an inner peripheral surface that is flush with the other side of the ridge portion and the tip. In which the step portion comprising a plane is in contact with the solution for liquid cooling.

According to the present invention, since the step portion which is a part of the metal frame is provided so as to be in contact with the liquid cooling solution, the step portion suitably acts on the convection of the liquid cooling solution, and The heat is efficiently transferred to the heat exchanger, and the cooling effect can be enhanced.

A liquid cooling unit according to another aspect of the present invention comprises:
An opening having a larger diameter than the opening of the metal frame is formed on the other surface of the metal frame to form a step for mounting the other transparent substrate.

A liquid cooling unit according to another aspect of the present invention comprises:
Among the two transparent substrates, the transparent substrate to which the emission-side polarizing plate is attached is made of sapphire or quartz.

According to the present invention, by using sapphire or quartz having high thermal conductivity, heat can be efficiently radiated and the cooling effect can be enhanced.

A liquid cooling unit according to another aspect of the present invention comprises:
The transparent substrate on which the light-exiting-side polarizing plate is to be adhered is made smaller among the two transparent substrates.

According to the present invention, it is possible to reduce the cost by reducing the size of the transparent substrate made of an expensive material such as sapphire or quartz.

A liquid cooling unit according to another aspect of the present invention comprises:
The metal frame is made of aluminum.

According to the present invention, it is possible to further enhance the cooling effect.

A liquid cooling unit according to another aspect of the present invention comprises:
At least a part of the corner of the metal frame is cut out in an L-shape.

A liquid cooling unit according to another aspect of the present invention comprises:
At least a part of the corner on the other surface side of the metal frame is cut out in an L-shape among the corners of the metal frame.

According to the present invention, it is possible to reduce the heat holding amount of the metal frame and further enhance the cooling effect.

A liquid cooling unit according to another aspect of the present invention comprises:
Equipped with two frame covers having openings for light passage,
Two frame covers are attached to the outer surfaces of the two transparent substrates with a packing interposed therebetween, and the whole is integrated.

According to the present invention, the packing is interposed between the outer surface of each of the two transparent substrates and the inner surface of each of the two frame covers. It is also possible to reduce the influence of changes in expansion and contraction of the metal frame and the like on the transparent substrate, and to obtain a highly reliable liquid cooling unit.

A liquid crystal projector according to one aspect of the present invention includes any one of the liquid cooling units described above.

According to the present invention, it is possible to obtain a liquid crystal projector having the above effects.

[0029]

FIG. 3 is a schematic plan view showing an optical system configuration of a liquid crystal projector incorporating a liquid cooling unit according to one embodiment of the present invention. As shown in FIG. 3, the liquid crystal projector 1 includes a light source 3 including a high-intensity lamp such as a metal halide lamp, a reflecting mirror 5 that reflects light from the light source 3, and an illuminance of reflected light from the reflecting mirror 5. An illumination optical system 7 for making the distribution uniform and entering the liquid crystal panel in a state where the polarization directions are aligned; and a dichroic mirror 9
a, 9b and a reflection mirror 10 for separating a light beam W emitted from the illumination optical system 7 into red, green, and blue light beams R, G, and B, and a liquid crystal corresponding to the red light beam R and the green light beam G, respectively. A color light separation optical system 9 for guiding the panel, a relay optical system 11 for guiding the blue light flux B among the respective color light fluxes separated by the color light separation optical system 9 to a corresponding liquid crystal panel, and modulating each color light flux according to given image information. Light modulating unit 13 having a liquid crystal panel 19 for performing the modulation, a prism 15 for synthesizing the modulated color light beams, and a projection surface 16 for synthesizing the synthesized light beams.
And a projection lens 17 for magnifying and projecting the image.

The light modulating section 13 has a liquid crystal panel 19 for modulating each color light beam according to given image information, and an incident side polarizing plate 21 has a transparent substrate 22 for heat radiation on its light incident surface side.
And a liquid cooling unit 25 in which a light-emitting side polarizing plate and its cooling mechanism are integrated. In the light modulation section 13, each color light beam separated by the color light separation optical system 9 is converted into an incident side polarizing plate 21.
To the S-polarized light, and the S-polarized light is
9, and only the P-polarized light component of the modulated light is transmitted from the exit-side polarizing plate.

The incident side polarizing plate 21 and the outgoing side polarizing plate respectively pass only one polarized light and block (absorb) the other polarized light, and generate heat by light absorption. Side polarizing plate 21, liquid crystal panel 19,
The liquid cooling units 25 are arranged separately from each other to prevent heat from being directly transmitted to the liquid crystal panel 19, and to allow air to flow through a space between the liquid cooling units by a cooling fan (not shown).

Transparent substrate 2 on which incident-side polarizing plate 21 is adhered
2 is desirably a sapphire glass plate or a quartz plate having high thermal conductivity. By using such a transparent substrate having high thermal conductivity, the heat of the incident side polarizing plate 21 is efficiently radiated and the durability is improved. Is obtained.

Hereinafter, the liquid cooling unit 25 will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a liquid cooling unit according to one embodiment of the present invention, and FIG. 2 is a sectional view of a main part of the liquid cooling unit according to one embodiment of the present invention. In both figures, the left side in the figure is the incident side, and the right side is the outgoing side. The liquid cooling unit 25 includes a frame cover 35, a packing 30, a transparent substrate 27 to which the light-exiting-side polarizing plate 23 is adhered, and a gasket 29, from the light-incident surface side of the metal frame 51. , Transparent substrate 31,
A packing 33 is arranged, and these are attached to a frame cover 35,
37 are integrally connected by mounting screws 39 using the insertion holes 35b and 37b provided at the four corners and the corresponding screw holes 61 of the metal frame 51, and the liquid cooling solution 41 is provided therein. Is enclosed.

Here, the liquid cooling unit 25 of the present embodiment
In (2), a step portion is constituted by one of a tip surface of a ridge portion 55 described later of the metal frame 51 and a side surface of the ridge portion 55 (hereinafter, described as a side surface on the emission side), The stepped portion is in contact with the liquid cooling solution 41, and a step is provided by a metal frame 51 in a space in which the liquid cooling solution 41 is sealed. The configuration of the characteristic portion will be described while detailing the constituent members.

The metal frame 51 has an opening 53 substantially at the center.
The opening 53 has a ridge 55 formed on the inner surface of the four sides of the opening 53 over the entire length. The output side polarizing plate 2 is provided on the incident side surface of the ridge 55.
The transparent substrate 27 to which 3 is attached is attached while being sandwiched between the packings 29 and 30. An opening having a larger diameter than the opening 53 is formed on the emission side surface of the metal frame 51 to form a step 57 for mounting the transparent substrate 31, and the transparent substrate 31 is sandwiched between the packings 33 and 34 at the step 57. It is attached in the state that was done. In addition, on the upper surface of the metal frame 51, an injection path 59 for injecting the liquid cooling solution 41 communicating with a space between the transparent substrate 27 and the transparent substrate 31 is formed,
The upper side is a screw hole into which the sealing screw 63 is screwed. At the four corners of the metal frame 51, there are formed screw holes 61 for mounting a frame cover, which penetrate in the thickness direction. The metal frame 51 is preferably made of aluminum having good thermal conductivity, but is not particularly limited as long as it is a metal material.

The transparent substrate 27 is made of sapphire or quartz having high thermal conductivity so as to efficiently radiate the heat of the output side polarizing plate 23 attached to the incident side surface. I have. Further, since the transparent substrate 27 is mounted using the ridge 55 of the metal frame 51,
It is smaller in size than the transparent substrate 31 mounted using the step 57 provided in the opening 53 of the metal frame 51. Since this transparent substrate 27 is made of sapphire or quartz, a cost advantage can be obtained by making this side small.

The packing 29 is made up of the transparent substrate 27 and the ridges 5.
5 are liquid-tightly sealed with each other to prevent leakage of the liquid cooling solution 41.
The inner peripheral surface of the opening 29 a is formed so as to be substantially flush with the distal end surface of the ridge 55 of the metal frame 51. The side face 55c on the incident side is kept out of contact with the liquid cooling solution 41. The packing 30 has the same configuration as the packing 29.

The transparent substrate 31 is desirably made of sapphire or quartz in consideration of heat radiation, and the side face 55 b on the emission side of the ridge 55 of the metal frame 51 is in contact with the liquid cooling solution 41. The projection 55 is arranged so as to be separated from the side surface 55b. Specifically, the mounting is performed by using the step 57 of the metal frame 51, and a packing 33 for preventing leakage of the liquid cooling solution 41 is interposed therebetween.

The packing 33 has a flat plate shape like the packing 29 and has an opening 33a formed at the center. The inner peripheral surface of the opening 33a is formed by the opening 53a of the metal frame 51.
Is formed so as to be substantially flush with the inner peripheral surface. Also,
The packing 34 has the same configuration as the packing 33.

The frame covers 35, 37 are provided with openings 35a, 37a for transmitting light.
a, 37a are respectively provided with a distal end face 55a of a ridge 55 of the metal frame 51 and an opening 53 of the metal frame 51.
Is formed so as to be substantially flush with the inner periphery of. And
An insertion hole 35b and an insertion hole 37b are formed at the four corners of the frame covers 35 and 37, respectively.
By screwing the mounting screw 39 using the insertion hole 37b and the screw holes 61 provided at the four corners of the metal frame 51, all the members are integrally connected.

Then, the liquid cooling solution 41 is supplied from an injection passage 59 for injecting the liquid cooling solution 41 provided on the upper surface of the metal frame 51.
Is injected, and the upper end is sealed with a sealing screw 63,
A liquid cooling unit 25 is configured.

As described above, the opening 5 of the metal frame 51
A protrusion 55 is provided on the inner peripheral portion of the four surfaces 3 over the entire length, and one side surface 55 c of the protrusion 55 is attached to the packing 2.
9, the other side surface 55b is opened, and the step portion 56 composed of the tip surface 55a of the ridge portion 55 and the emission side surface 55b is configured to be in contact with the liquid cooling solution 41. I have.

The liquid cooling unit 25 constructed as described above
In, the heat of the emission side polarizing plate generated by the light absorption is transmitted to the liquid cooling solution 41 through the transparent substrate 27. Here, since the transparent substrate 27 is made of sapphire glass or quartz having high thermal conductivity, heat can be efficiently radiated. Further, the heat transmitted to the liquid cooling solution 41 via the transparent substrate 27 is transferred by convection to the metal frame 5.
Transfer to 1. At this time, the step 56 of the metal frame 51 provided so as to be in contact with the liquid cooling solution 41 is
1, and the heat is efficiently transmitted to the metal frame 51, and the heat of the metal frame 51 is released to the outside by air from a cooling fan (not shown).

As described above, according to the present embodiment, the step portion 56 of the metal frame 51 is configured to be in contact with the liquid cooling solution 41, so that the step portion 56 suitably acts on the convection of the liquid cooling solution 41. Heat is efficiently transmitted to the metal frame 51, and the cooling effect can be enhanced.

Further, since the transparent substrate 27 made of sapphire or quartz is formed small, it is possible to reduce the cost.

Further, since the packings 30, 34 are interposed between the frame covers 35, 37 and the transparent substrates 27, 31, respectively, the bonding between them can be made firm and stable and integrated. It is possible to reduce the influence of changes in expansion and contraction of the metal frame 51 and the like on the transparent substrates 27 and 31, and the liquid cooling unit 2 having high reliability
5 can be obtained.

Further, in addition to the structure described above, as shown in FIG.
The provision of the letter-shaped cutout 25a makes it possible to reduce the heat holding amount and further enhance the cooling effect. Also,
By configuring the cutout portion 25a in a fin shape, it is possible to further enhance the cooling effect. Here, since the transparent substrate 27 on the incident side is configured to be smaller than the transparent substrate 31 on the emitting side, the corners on the incident side are cut out. However, the corners on the emitting side may be used. Similarly, the notch 25a may be formed in a fin shape.

In this embodiment, the packing 2 is provided on both sides of the transparent substrate 27 and the transparent substrate 31, respectively.
9 and 30, and the case where the packings 33 and 34 are provided, the outer packing 30 and the packing 3 are provided as shown in FIG.
4 may be omitted.

Further, in this embodiment, the case where the step portion 56 is formed by the tip end surface 55a and the emission side surface 55b of the protruding portion 55 of the metal frame 51 has been described, but the reverse is also possible. good. That is, as shown in FIG. 6, a step 56 may be formed by the tip end surface 55a of the ridge 55 and the incident side surface 55c. In this case, the transparent substrate 27 is formed on the incident surface of the metal frame 51. A mounting step 57 is provided, and the transparent substrate 27 is mounted from the incident side of the metal frame 51 by using the step 57, and transparent from the emission side of the metal frame 51 by using the projection 55 of the metal frame 51. The board 31 is mounted.

In the present embodiment, the liquid cooling unit 25 of the present embodiment is a so-called three-panel type using three liquid crystal panels 19 corresponding to each color of RGB.
Is applied, but the invention can be similarly applied to a single-panel type using one liquid crystal panel.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a liquid cooling unit according to an embodiment of the present invention.

FIG. 2 is a sectional view of a liquid cooling unit according to one embodiment of the present invention.

FIG. 3 is a schematic plan view showing an optical system configuration of a liquid crystal projector incorporating the liquid cooling unit according to one embodiment of the present invention.

FIG. 4 is a cross-sectional view of the liquid cooling unit when the corners on the incident side of the metal frame and the frame cover of FIG. 2 are cut out in an L shape.

FIG. 5 is a sectional view of the liquid cooling unit when the outer packing is omitted in FIG.

FIG. 6 is a cross-sectional view of the liquid cooling unit in a case where a step portion is formed on a side surface opposite to a ridge portion of a metal frame in FIG.

FIG. 7 shows a known optical system in a liquid crystal projector.

FIG. 8 is an explanatory diagram of a conventional air-cooled cooling system.

FIG. 9 is an explanatory diagram of a conventional cooling method using a liquid cooling method.

FIG. 10 is an enlarged sectional view of the liquid cooling unit of FIG. 9;

[Explanation of symbols]

 23 Outgoing side polarizing plate 25 Liquid cooling unit 27, 31 Transparent substrate 29, 30, 33, 34 Packing 29a, 33a Opening 35, 37 Frame cover 41 Liquid cooling solution 50 Metal frame 53 Opening 55 Projection 56 Step 57 Step for mounting transparent substrate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09F 9/00 360 G09F 9/00 360Z F term (Reference) 2H049 BA02 BB11 BB22 BC22 2H088 EA12 EA68 HA01 HA18 HA28 2H091 FA05X FA08X FA08Z FA21X FA26X GA01 LA04 5G435 AA12 BB12 BB17 CC12 DD02 DD04 EE05 GG01 GG03 GG04 GG08 GG28 GG44 LL15

Claims (9)

[Claims] 1. A liquid cooling solution is sealed between two transparent substrates, and an outgoing side polarized light through which outgoing light from a liquid crystal panel passes through an outer surface of an incoming side transparent substrate of the two transparent substrates. A liquid cooling unit having a plate attached thereto for cooling, comprising: a metal frame having an opening, and a ridge portion formed on four inner surfaces of the opening over the entire length. From one surface side of the frame, one of the two transparent substrates is mounted on the side surface of the ridge via the first packing, and from the other surface side of the metal frame, The transparent substrate is separated from the ridge and is mounted via a second packing, and the first packing has an inner peripheral surface that is substantially flush with a tip end surface of the ridge of the metal frame. And the step formed by the side surface and the front end surface on the other surface side of the ridge portion is formed by the liquid Liquid cooling unit, characterized in that the contact with the use solution. 2. The step according to claim 1, wherein an opening having a diameter larger than that of the opening of the metal frame is formed on the other surface of the metal frame to form a step for mounting the other transparent substrate. Liquid cooling unit. 3. The liquid cooling unit according to claim 1, wherein, of the two transparent substrates, the transparent substrate to which the emission-side polarizing plate is attached is made of sapphire or quartz. 4. The liquid cooling unit according to claim 3, wherein, of the two transparent substrates, the transparent substrate to which the emission-side polarizing plate is attached is configured to be small. 5. The liquid cooling unit according to claim 1, wherein the metal frame is made of aluminum. 6. The liquid cooling unit according to claim 1, wherein at least a part of a corner of the metal frame is cut out in an L shape. 7. The metal frame according to claim 6, wherein at least a part of the corner of the other side of the metal frame is cut out in an L shape. Liquid cooling unit. 8. An image forming apparatus comprising: two frame covers each having an opening for transmitting light; and mounting the two frame covers by interposing a packing between respective outer surfaces of the two transparent substrates. The liquid cooling unit according to claim 1, wherein the liquid cooling unit is integrated. 9. A liquid crystal projector comprising the liquid cooling unit according to claim 1.