JPH0782810B2 - Projection device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a projection system for a projection television, and more particularly to a projection apparatus suitable for reducing the number of parts and the number of assembly steps, reducing the weight, and achieving high image quality.

[Conventional technology]

In the projection device of the projection television, the projection tube is made to have a high output in order to improve the brightness, and the projection tube is cooled by a cooling liquid in order to prevent the projection tube from being broken by the heat generated thereby.

In this method, as described in Japanese Utility Model Publication No. 62-30201, the projection tube and the lens closest to the projection tube (hereinafter referred to as the incident lens)
There are brackets that are arranged opposite to each other and that enclose the cooling liquid. This bracket has a role of radiating the heat generated from the projection tube.

Conventionally, the bracket has been manufactured by die-casting of aluminum having high thermal conductivity in order to increase the heat dissipation capability. Since the accuracy of die casting is insufficient for use as an optical component, dimensional accuracy is achieved by post-processing. In addition, the screw part is formed by post-processing.

The bracket and the projection tube, and the bracket and the incident lens are fixed by tightening screws through various parts such as a pressing plate and an O-ring in order to prevent leakage of the cooling spout.

Further, the plurality of lenses are fixed at a predetermined interval by a lens barrel having a double structure made of plastic. The inner lens barrel and the outer lens barrel are fixed with screws, and the outer lens barrel is fixed with screws to the bracket. The inner barrel can be fixed to the outer barrel by continuously changing its position. Therefore, the focal length can be changed by adjusting the positional relationship between the incident lens and other lens groups.

[Problems to be solved by the invention]

In the above-mentioned prior art, the number of parts, that is, the assembling property and the weight are not sufficiently taken into consideration.

2) Since the number of parts is large and post-processing is required, the number of assembling steps is large and the assembling cost is high.

3) When the number of parts is increased, the assembly accuracy is deteriorated, the positional deviation between the projection tube and the lens and the positional deviation between the lenses occur, and the image quality is deteriorated.

4) Due to its large weight, assembly work is difficult.

5) Due to the heavy weight of the projection device, the weight of the projection television set is also heavy and difficult to transport.

There were problems such as.

It is an object of the present invention to provide a projection apparatus that maintains the function of cooling the projection tube, reduces the number of parts and the number of assembling steps to achieve low cost, high image quality, and further weight reduction. .

[Means for solving problems]

 The above object is achieved by the following.

1) The bracket has a composite structure of plastic and a high thermal conductive material.

2) The following means are used according to the method of the above structure.

a) A structure in which the high thermal conductive material penetrates through the plastic i) A liquid-tightness holding means such as adhesive is used at the boundary between the plastic and the high thermal conductive material.

ii) The high thermal conductive material was formed in advance, and antireflection means such as blackening treatment was used on the surface thereof.

b) The structure in which the high thermal conductive material does not penetrate into the plastic i) The thickness of the plastic between the cooling liquid and the high thermal conductive material is extremely thin.

ii) Several thick parts are provided in the thin plastic part.

iii) The linear expansion coefficient of plastic and high thermal conductivity material shall be small.

3) The bracket has a structure for determining the inter-plane distance of the lens group.

4) Fixing the bracket and the incident lens by welding,
Adhesion, heat caulking, etc.

5) The female screw part is formed in advance by metal or ceramic and inserted.

6) The plastic portion of the bracket has anti-reflection means such as black one.

[Action]

The use of plastic brackets reduces the number of parts and the number of assembly steps due to the following.

1) High precision can be obtained only by injection molding, so no post-processing is required.

2) Since the bracket and the incident lens are both plastic, liquid-tight welding is possible. No O-rings, holding plates or screws required.

3) Brackets and bellows can also be welded, and a holding plate and screws are not required.

4) The bracket can have a part of the function of the lens barrel, and the number of parts of the lens barrel can be reduced.

5) If the bracket is made of plastic, other parts can be fixed by heat caulking and screws are not required.

As a result of the reduction of the number of parts as described above, the assembly accuracy is improved,
The image quality is improved.

Further, the weight is reduced from the following points.

1) It is not necessary to increase the wall thickness by using a plastic having a strength similar to that of metal, so-called engineering plastic.

2) While the specific gravity of aluminum is 2.7, generally used plastics are up to about 1.9.

The bracket that is inserted into the plastic by penetrating through the high thermal conductive material is: 1) Since the heat is radiated by the high thermal conductive material, even if the thermal conductivity of the plastic is low, it does not affect the cooling capacity. Sufficient heat dissipation capability can be obtained by increasing the heat transfer area of the heat dissipation part.

2) The plastic part has almost no effect on the heat dissipation capability. Therefore, a sufficient thickness can be obtained in terms of strength.

3) Since the interface between the high thermal conductive material and the plastic is liquid-tightly sealed, no liquid leakage occurs.

4) Both plastic and high thermal conductive material have anti-reflection treatment such as black coating, so that deterioration of contrast does not occur.

On the other hand, the bracket with insert made of high thermal conductive material so as not to penetrate the plastic 1) Since the thickness of the plastic part for radiating heat is small, it is easy to conduct heat even if the thermal conductivity of plastic is small. Increase the heat transfer area of the high thermal conductive material,
Sufficient heat dissipation capacity is obtained.

2) By providing a thick runner portion in the middle of the thin portion, the structure is such that the resin does not flow in the thin portion for a long time. As a result, the fluidity is improved and it is possible to mold even a thin wall.

3) By passing the resin through the high thermal conductive material, the plastic portion becomes thick, and even if there is a difference in the expansion coefficient, it is difficult to peel it off and the leakage of the cooling liquid does not occur.

4) By making the plastic and the high thermal conductive material close to each other in linear expansion coefficient, the dimensional difference between the two is small even when expanded, and peeling hardly occurs.

Further, since the female thread portion is made of metal, ceramic, or the like, it has sufficient strength against the tightening force of the screw.

Further, since the plastic antireflection treatment is applied, the light emitted from the projection tube is not reflected by the plastic, which deteriorates the contrast and does not deteriorate the image quality.

The bracket encloses a cooling liquid and is heated by heat generated from the projection tube. Usually, the bracket and the cooling liquid are heated up to about 90 ° C. Therefore, there is a fear that it may be deformed by heat and the position accuracy may be deteriorated, the image quality may be deteriorated, liquid may leak, or the liquid may be dissolved in the cooling liquid. However, the use of so-called engineering plastic having excellent heat resistance and chemical resistance does not cause any particular problem.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is an exploded perspective view of a projection device according to an embodiment of the present invention. 2 is a sectional view taken along the line AA of the projection apparatus of FIG. 1 when assembled, FIG. 3 is a sectional view taken along the line BB of the projection apparatus of FIG. 1 assembled, and FIG. 4 is a section C of FIG. FIG.

Bracket 1, projection tube 2, inner lens barrel 3, lenses 4a, 4b, 4c, 4d, O-ring 6 to keep bracket 1 and projection tube 2 liquid-tight, projection tube holding plate 7, projection tube holder on bracket 1 A projection tube fixing screw 8 and a washer 27 for fixing the plate 7, an elastic material 9 for intervening between the projection tube 2 and the projection tube holding plate 7, and an inner lens barrel fixing screw 10 for fixing the inner lens barrel 3 to the bracket 1. And a washer 25, a bellows 11, a coolant inlet screw 12, an inlet O-ring 13, and lens holders 14b and 14d for fixing the lenses 4b and 4d to the inner barrel 3.

The bracket 1 has a pre-formed heat dissipating portion 1a made of a high thermal conductive material.
Also, the fixing parts 1b and 1c of the female screws corresponding to the projection tube fixing screw 8 and the injection port screw 12 are inserted.

The bracket 1 is provided with a lens barrel portion 1d, and the lens barrel portion 1d
An inner lens barrel fixing hole 1m for fixing the inner lens barrel 3 and adjusting the focal length of the lens system is formed in a slender shape.

On the other hand, the inner barrel 3 is formed with a protrusion 3a for fixing to the bracket 1, and the protrusion 3a is formed with a female screw corresponding to the inner barrel fixing screw 10.

On the inner surface of the bracket 1, there is formed an incident lens mounting recess 1e for positioning the lens (incident lens) 4a closest to the projection tube.

On the other hand, the incident lens 4a, the positioning projection 4a ₁ against the concave 1e is provided.

In addition, a recess for inserting the O-ring 6 is formed on the inner surface of the bracket 1.
1g is provided.

Further, a positioning recess 1f for positioning the bellows 11 is provided on the outer surface of the bracket 1.

On the other hand, the bellows 11 is provided with a positioning projection 11a.

Further, the bracket 1 has a concave portion into which an inlet O-ring is inserted.
1j is provided.

On the back surface of the projection tube 2, there is provided a projection 2a for holding down the projection tube holding plate 7. The projection tube holding plate 7 is provided with a hole 7a into which the projection tube fixing screw 8 is inserted.

Air gap 15 surrounded by bracket 1, incident lens 4a, and projection tube 2
A cooling liquid 16 is sealed in. A pressure adjusting chamber 26 surrounded by the bellows 11 and the bracket 1 communicates with the space 15.

The assembling of the projection device having the above configuration is as follows. The bracket 1 is obtained by so-called insert molding in which the heat radiating portion 1a and the fixed parts 1b and 1c made of a high heat conductive material which are formed in advance are inserted. Here, the surface 1a ₁ of the heat radiating portion 1a that comes into contact with the cooling liquid 16 is painted black before insert molding is performed. After the insert molding, the boundary portion between the plastic portion of the bracket 1 and the heat radiating portion 1a of the high thermal conductive material is liquid-tightly bonded with a sealing material such as silicone.

Next, the convex portion 4a ₁ for positioning the incident lens 4a is attached to the bracket 1
The contact surface 18 between the bracket 1 and the incident lens 4a is welded in a liquid-tight manner by using an ultrasonic device so as to match the concave portion 1e for mounting the incident lens.

Next, the positioning projection 11a of the bellows 11 is aligned with the positioning recess 1f of the bracket 1 so that the bracket 1 and the bellows
The contact surface 19 of 11 is welded in a liquid-tight manner.

Next, the bracket 1 and the projection tube 2 are fixed. First, the O-ring 6 is inserted into the concave portion 1g of the bracket 1 and the projection tube 2 is mounted. At this time, the bracket 1 and the projection tube 2 are positioned by the inner surface portion 1i of the bracket. After that, the elastic material 9 is placed on the projection 2a provided on the back surface of the projection tube 2, and the projection tube holding plate 7 is placed on the bracket 1 and the elastic material 9. Then, the projection tube fixing screw 8 is tightened to the fixing component 1b inserted into the bracket 1 through the hole 7a of the projection tube holding plate 7 via the washer 27. The O-ring 6 is compressed by this tightening force, and the bracket 1 and the projection tube 2 come into liquid-tight contact.

On the other hand, the lenses 4b, 4c, 4d are fixed to the inner lens barrel 3 with a predetermined interval. First, the middle lens 4c is fixed by the protrusion 3b provided in the inner lens barrel 3. Then the lenses on both sides
4b and 4d are fixed with the holding plates 14b and 14d, respectively.

Then, the bracket 1 to which the projection tube 2, the incident lens 4a and the bellows 11 are fixed, and the inner lens barrel 3 to which the lenses 4b, 4c and 4d are fixed are fixed. That is, the fixing screw 10 is fastened to the female screw portion formed on the protrusion 3a of the inner lens barrel 3 through the hole 1m provided in the lens barrel portion 1d of the bracket 1 and the washer 25.

When the assembly is completed, the cooling liquid 16 is injected from the injection port 14 in a vacuum state. When the injection is completed, the O-ring 13 for the injection port is fitted in the injection port recess 1j provided in the bracket 1, and the injection port screw 12 is fastened to the fixed component 1c insert-molded in the bracket 1.

Due to this tightening force, the O-ring 13 is compressed and liquid tightness is maintained.

In the projection apparatus assembled as described above, the boundary surface between the bracket 1 and the incident lens 4a and the bracket 1 and the bellows 11 is kept liquid-tight by welding of resin, and the bracket 1 and the projection tube 2 and the bracket 1 are The boundary surface of the inlet screw 12 is kept liquid-tight by the compression of the O-ring. In addition, since the portion of the boundary surface between the plastic portion of the bracket 1 and the heat radiating portion 1a that is inserted is in contact with the cooling liquid, liquid leakage does not occur.

The positional relationship between the bracket 1 and the inner lens barrel 3 is determined by adjusting the focus when the image is projected. That is,
Loosen the fixing screw 10 and move the fixing screw 10 over the hole 1m of the lens barrel portion 1d of the bracket 1 to change the inner lens barrel 3 forward and backward. Thereby, the distance between the lens surfaces changes, and the focus can be adjusted.

The operation of this projection device is as follows.

When the power of the projection device is turned on, light is emitted from the phosphor screen (not shown) of the projection tube 2, and the cooling liquid and the lenses 4a, 4b, 4c, 4d are emitted.
, And the image on the projection tube is enlarged and projected on a screen (not shown).

At this time, the surface of the projection tube 2 is heated by the generated heat. The heat of the surface of the projection tube 2 is transferred to the cooling liquid 16,
16 temperature rises. The heat of the cooling liquid 16 is further transferred to the bracket 1 and the incident lens 4a.

Since the heat dissipation component inserted in the bracket 1 has a thermal conductivity much higher than that of plastic, most of the heat from the cooling liquid is conducted through the heat dissipation component and transferred to the ambient air.

Since the temperature of the cooling liquid rises due to the heat generated from the projection tube 2,
Coolant pressure increases. Bellows changes in pressure 11
It is adjusted by. The bellows 11 is made of an elastic material such as rubber, and its shape can be changed freely. Therefore, the pressure is adjusted by changing the volume by changing the shape.

The light emitted from the projection tube 2 also strikes parts other than the lenses 4a, 4b, 4c, 4d. That is, it corresponds to the plastic portion of the bracket 1 and the heat dissipation component. Since black plastic is used and the heat dissipation parts are painted black, there is little reflection at these parts. Therefore, the reflected light is prevented from degrading the contrast of the image.

The material of each component is as follows. As the cooling liquid 16, an ethylene glycol-based solvent was used in this embodiment. The lenses 4a to 4d may be made of any transparent resin such as polymethylmethacrylate or polycarbonate, but polymethylmethacrylate is used in this embodiment. The plastic used for the bracket 1 may be selected from materials that are resistant to the ethylene glycol-based solvent selected as the coolant 16 and have excellent heat resistance and strength. There are polyphenylene sulfide, polyether sulfone, and the like. In this example, in consideration of the material cost, polyphenylene sulfide glass fiber reinforced 30% black was used.

Further, as the material of the heat dissipation component 1a inserted into the bracket 1, copper, aluminum or the like having high thermal conductivity can be used. In this embodiment, aluminum is used. Further, the inserted fixed parts 1b and 1c can be made of metal or ceramic, and brass is used in this embodiment.

In the above embodiment, the portion 1d for fixing the inner lens barrel of the bracket 1 has the same function as the conventional outer lens barrel.

Therefore, the outer lens barrel could be eliminated. Along with that, it is no longer necessary to manufacture a mold for molding the outer lens barrel.

In addition, the number of screws for fixing the outer lens barrel and the bracket, the components for fixing the incident lens and the bracket (holding plate, O-ring, screws, etc.), and the components for fixing the bellows and the bracket are reduced.

Moreover, since it is made with high precision by injection molding, no post-processing is required.

Therefore, the cost of parts and the number of assembly steps are reduced. In addition, since the number of parts has been reduced, the positional displacement between the outer lens barrel and the bracket does not occur, the positional accuracy of the lens and CRT is improved, and the image quality is improved.

In addition, a plastic bracket has reduced weight.

In this embodiment, of the boundary between the plastic of the bracket 1 and the heat radiating portion, the portion that comes into contact with the cooling liquid is the sealing material 17.
Liquid tightness was maintained by bonding the
The portion to which 17 is adhered is not limited to the portion that contacts the cooling liquid, and may be in the middle of the boundary surface or in the portion that contacts the air. If the gap 15 enclosing the cooling liquid 16 maintains liquid tightness due to the adhesion of the sealing material 17, the adhesion position does not become an essential problem.

In this embodiment, black plastic is used, and the heat dissipation part 1a
A black coating was applied to the above to prevent reflection, but other reflection prevention such as roughening the surface where reflection occurs may be applied.

Even if the assembling procedure is different from the procedure of this embodiment, no problem occurs.

In this embodiment, the entrance lens 4a is the cooling liquid 16 for the bracket 1.
Although the structure is welded to the side surface, the incident lens 4a may be welded to the surface opposite to the cooling liquid 16 as shown in FIG.

FIG. 6 shows a projection device according to another embodiment of the present invention.

The structure is almost the same as that of the embodiment shown in FIG. The difference is that the heat radiating portion 1a ′ inserted in the bracket 1 is different.
Is. In the embodiment of FIG. 1, the heat radiating portion 1a penetrates to the cooling liquid 16 side, whereas in this embodiment, the heat radiating portion 1a 'does not penetrate.

7 is a sectional (DD) perspective view of a portion of the bracket 1 of FIG. 6 where the heat radiating portion 1a 'is inserted, and FIG. 8 is a sectional plan view of the insert portion of FIG.

As shown in FIG. 8, the heat radiating portion 1a 'has a length d from the surface in contact with the cooling liquid. If d is large, the plastic part becomes thicker and the cooling capacity becomes smaller. If this structure is used as a projection television projection device,
It has been found that this minimum wall thickness d is 1 mm or less, preferably 0.5 mm or less, in order to satisfy the heat dissipation capability.

On the other hand, if it is too thin, moldability is poor and defects occur, and there are problems such as cracking during use. This thin part has a runner part
There are many 20 protrusions. The plastic parts are connected by the penetration parts 21 and 22 in the heat dissipation part 1a '. With such a structure, even if the minimum wall thickness d is thin, the distance that the resin flows through the thin wall portion is short, the fluidity of the resin is improved, and molding can be performed. However, even in this structure, if d is 0.1 mm or less, molding is difficult, and d ≧ 0.1
It has been found that mm is preferred.

The assembling of the projection device having this structure is almost the same as that of the embodiment shown in FIG. In this embodiment, since the heat radiating portion 1a 'does not come into contact with the cooling liquid 16, it is not necessary to apply black paint to the heat radiating portion 1a' to be inserted or to bond the sealing material.

The operation is almost the same as that of the above-mentioned embodiment. In the heat radiation method, heat is transferred from the cooling liquid 16 to the plastic part, and then to the heat radiation component 1a '. Then, heat is radiated from the portion 1a ′ ₁ in contact with the air.

Even when the temperature rises, the penetration portions 21 and 22 reinforce the peeling strength of the plastic portion and the heat radiating portion.
Therefore, the cooling liquid 16 does not leak.

The material of each part was the same as that of the above-mentioned embodiment. The effects of reducing the number of parts and the number of assembly steps were similar to those of the previous example.

FIG. 9 is a diagram showing an embodiment in which the method of fixing the bracket 1 and the entrance lens 4a in the embodiment of FIGS. 1 and 6 is different.

As shown in FIG. 9 (a), the bracket 1 has an incident lens.
Recess 1e for positioning with 4a, O-ring recess 1k,
A thermal caulking protrusion 1l is provided. On the other hand, the entrance lens 4a is provided with a positioning projection 4a ₁ and a hole 4a ₂ .

As shown in Fig. 9 (b), the fixing method is to insert the O-ring 23 into the bracket recess 1k, and then to insert the hole of the entrance lens 4a.
Pass 4a ₂ through bracket protrusion 1l. Then, the convex portion of the lens 4a is aligned with the concave portion 1e of the bracket 1 for positioning.

When the position is determined, the bracket 1 and the entrance lens 4a are pressed to compress the O-ring 23. In that state, the protrusion 1l of the bracket 1 is melted by ultrasonic waves or the like to form a crimp as shown in FIG. 9 (c).

Compared to the welding of the contact surface shown in FIG. 4, the number of O-rings is increased, but the number of parts is reduced as compared with the conventional case because a pressing plate and screws are not required.

This thermal crimping method can be similarly used for fixing the bellows 11. In the case of the bellows 11, since the bellows itself is made of an elastic body such as rubber, it can be fixed without the need for an O-ring.

Further, the number of parts can be reduced by fixing by adhesion other than ultrasonic welding or heat caulking.

In the embodiment of FIG. 9, the entrance lens 4a is fixed to the surface of the bracket 1 on the cooling liquid 16 side, but as described in the first embodiment, it may be fixed to the opposite surface.

Further, in this embodiment, the heat radiating portion of the high thermal conductive material has a linear fin shape as shown in FIG. 10 (a), but even the same linear fin has a thinned tip as shown in FIG. 10 (b), First
The same effect was obtained with a protruding fin as shown in FIG. 10 (c).

Further, in the above embodiment, the heat radiating section 1a or 1a 'was constituted by one component, but the penetrating method of FIG.
Pipe 24 or 2 as shown in the non-penetrating method in Figure (b)
There is no problem even if a plurality of 4'and the like are collected to form the heat dissipation portion 1a or 1a '.

〔The invention's effect〕

As described above, according to the present invention, since the bracket is made of plastic and the heat dissipating portion of the high thermal conductive material is inserted, the heat dissipating ability can be maintained and the molding and welding can be performed. This has the effect of reducing man-hours, improving image quality by assembling accuracy, and reducing weight.

[Brief description of drawings]

1 is an exploded perspective view showing a projection apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, FIG. 3 is a sectional view taken along the line BB of FIG. 1, and FIG. 2 is an enlarged view of part C in FIG. 2, FIG. 5 is a partial sectional view showing another embodiment of part C, FIG. 6 is a sectional view showing a projection device of another embodiment of the present invention, and FIG. 6 is a sectional perspective view taken along the line DD of FIG. 6, FIG. 8 is a sectional view of FIG. 7, and FIG. 9 is a partial sectional view showing another embodiment of a C portion in FIG. FIG. 11 is a partial cross-sectional view showing another embodiment of the heat dissipation plate. 1 …… Bracket, 2 …… Projection tube 3 …… Inner lens barrel, 4a …… Injection lens 11 …… Bellows, 14 …… Injection port

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication H04N 5/74 G (72) Inventor Shigeru Mori 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Stock company Home Appliances Research Laboratory, Hitachi, Ltd. (72) Toru Numata, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Stock Company Hitachi, Ltd. Yokohama Plant (56) Reference JP-A-59-68154 (JP, A) JP-A-58-154146 (JP, A) Practical application Sho-62-65764 (JP, U)

Claims (19)

[Claims] 1. A projection tube, a bracket arranged on the front surface of the projection tube for fixing an incident lens arranged closest to the projection tube, and surrounded by the projection tube, the incident lens and the bracket. In a projection television projection device having a cooling liquid filled in a space, the bracket is made of plastic, and the incident lens is liquid-tightly fixed inside the bracket, and a plurality of lenses are attached to the bracket. A projection apparatus, wherein a lens barrel portion is formed which allows the mounted inner lens barrel to be positionally adjusted in the axial direction of the lens barrel. 2. The projection apparatus according to claim 1, wherein the plastic material forming the bracket is glass fiber reinforced polyphenylene sulfide. 3. The projection device according to claim 1, wherein the cooling liquid is an ethylene glycol-based transparent liquid. 4. The projection apparatus according to claim 1, wherein the fixing means for fixing the bracket and the incident lens is liquid-tightly welded, bonded, or heat-crimped. 5. The projection device according to claim 1, wherein the screw part of the bracket is formed by insert molding a preformed screw. 6. The projection device according to claim 1, wherein the plastic is black. 7. A projection tube, a bracket for fixing an incident lens arranged on the front surface of the projection tube and closest to the projection tube, surrounded by the projection tube, the incident lens and the bracket. In a projection television projection device having a cooling liquid filled in a space, the bracket is made of plastic, and the incident lens is liquid-tightly fixed to the bracket,
A projection device characterized in that a high thermal conductive member is insert-molded on the bracket, one end of the high thermal conductive member is in contact with the cooling liquid, and the other end of the high thermal conductive member is in contact with outside air. . 8. The projection device according to claim 7, wherein the plastic material forming the bracket is glass fiber reinforced polyphenylene sulfide. 9. The projection apparatus according to claim 7, wherein the cooling liquid is an ethylene glycol-based transparent liquid. 10. The projection device according to claim 7, wherein the high thermal conductive member is copper or aluminum. 11. The projection device according to claim 7, wherein the fixing means for fixing the bracket and the incident lens is liquid-tightly welded, bonded, or heat-crimped. 12. The projection device according to claim 7, wherein the threaded portion of the bracket is formed by insert molding a preformed screw. 13. The projection device according to claim 7, wherein the plastic is black. 14. A projection tube, a bracket for fixing an incident lens arranged on the front surface of the projection tube and arranged closest to the projection tube, and surrounded by the projection tube, the incident lens and the bracket. In a projection television projection device having a cooling liquid filled in a space, the bracket is made of plastic, and a high thermal conductive member is insert-molded in the bracket,
A projection device, wherein the thickness d of the plastic between the high thermal conductive member and the cooling liquid is 1 mm or less. 15. The projection device according to claim 14, wherein the plastic material forming the bracket is glass fiber reinforced polyphenylene sulfide. 16. The projection device according to claim 14, wherein the cooling liquid is an ethylene glycol-based transparent liquid. 17. The projection device according to claim 14, wherein the high thermal conductive member is copper or aluminum. 18. The projection device according to claim 14, wherein the screw portion of the bracket is formed by insert molding a preformed screw. 19. The projection device according to claim 14, wherein the plastic is black.