JPH03280335A - Lens-consolidated projector tube and projection type image receiving machine incorporating the same - Google Patents

Abstract

PURPOSE:To make the internal pressure of an optical coupling part equal to the atmospheric pressure and facilitate manufacture of the optical coupling part by providing an air chamber having an opening covered with a continuously porous material in such an arrangement as in communication with the optical coupling part. CONSTITUTION:When the surface of a cooling liquid 2 rises, the air in an air chamber 7 flows out through continuous holes in a continuously porous member 8 covering an opening 9, so that the volume change of the cooling liquid 2 is absorbed in this air chamber 7, and the internal pressure of an optical coupling part is kept constant. Then, if power to a projector tube 1 is shut off, the temp. of the cooling liquid 2 sinks with temp. sink of the projector tube 1. When the temp. of the liquid 2 has returned e.g. to 20 deg.C, the volume of the liquid 2 decreases contrary to the case with temp. rise, so that the liquid surface sinks. With this sink of liquid 2 surface, the external air intrudes into the air chamber 7 via the continuous holes in the porous member 8, so that the internal pressure of the optical coupling part is kept constant.

Description

Detailed Description of the Invention [Field of Industrial Application J] The present invention relates to a lens-integrated projection tube in which a lens and a projection tube are optically coupled by a cooling liquid, and a projection-type receiver having the lens-integrated projection tube. . [Prior Art] Conventionally, in a projection type receiver that enlarges and projects an image onto a screen using a projection tube, in order to improve the brightness and contrast of the image, a lens unit is used in which the lens and the projection tube are optically coupled by a coolant. A body projection tube is used (Denshi Gijutsu Shuppan “Television Technology” Vol. 34. P, 28-P.
, 31.198 [1 year]. FIG. 6 is a sectional view showing the basic structure of the lens-integrated projection tube. This lens-integrated projection tube includes a projection tube 61 and a projection tube 61.
a lens 65 and a projection lens group 66 for enlarging the image of
(some lenses are omitted), an aluminum bracket 64 that is provided with heat dissipation fins (not shown) and is treated with anti-reflection black alumite, and an O-ring 63 made of nitrile rubber, silicone rubber, etc. Projection tube 61. No. 65.0 Rings 63. A cooling liquid 62 (for example, an aqueous solution of ethylene glycol) having high light transmittance and good thermal conductivity is filled in the space sealed by the bracket 64 (hereinafter referred to as "optical coupling part"). have In this lens-integrated projection tube, since the face plate of the projection tube 61 is cooled by the cooling liquid 62, an increase in the temperature of the phosphor screen of the projection tube 61 can be prevented, so that the brightness of the image can be improved. In addition, reflection of light occurring on the surfaces of the face plate of the projection tube 61 and the second lune 65 can be prevented by making the refractive index of the coolant 62 approximately equal to the refractive index of the face plate and the second lune 65. Contrast can be improved. However, in this lens-integrated projection tube, when the volume of the cooling liquid 62 expands or contracts due to temperature changes, the internal pressure of the optical coupling section changes significantly. There are drawbacks such as damage to the first lun 65, 0 ring 63, etc., leakage of the coolant 62, and air suction. In order to compensate for these drawbacks, in the lens-integrated projection tube described in Japanese Patent Publication No. 63-64115, a transparent resin bag containing a cooling liquid is glued to the projection tube and the first lens, and a side surface of the transparent resin bag is attached. An elastic bag is provided so that the cooling liquid can flow in and out. Furthermore, in the lens-integrated projection tube described in Japanese Utility Model Application Publication No. 62-103154, a pressure regulating chamber is formed in the bracket, and a piston is provided in the pressure regulating chamber, and the piston is moved in accordance with the expansion or contraction of the cooling liquid. It's being moved. [Problem to be Solved by the Invention J] The lens-integrated projection tube described in Japanese Patent Publication No. 63-64115 described above has a method in which a transparent resin bag containing the cooling liquid is glued to the projection tube and the first lens, Since it is necessary to provide the elastic bag in the transparent resin bag, there is a drawback that the manufacturing process of the optical coupling part becomes complicated. Further, since the lens-integrated projection tube described in the above-mentioned Japanese Utility Model Publication No. 62-103354 does not have anything to support the piston, a predetermined frictional force is generated between the piston and the inner wall of the pressure regulating chamber. Since the internal pressure of the optical coupling part cannot be made equal to atmospheric pressure, there is a drawback that it is necessary to ensure a predetermined strength of the optical coupling part. An object of the present invention is to provide a lens-integrated projection tube in which the internal pressure of an optical coupling part can be made equal to atmospheric pressure and the manufacturing process of the optical coupling part is easy, and a projection-type receiver having the lens-integrated projection tube. It's about doing. [Means for Solving the Problems J] A lens-integrated projection tube of the present invention is a lens-integrated projection tube in which a projection tube and a projection lens are integrated via an optical coupling portion filled with a cooling liquid. A hollow air chamber having an opening covered with a continuous porous member is provided in communication with the optical coupling part,
It is preferable that the continuous porous member has water repellency. A projection type receiver of the present invention has a lens-integrated projection tube according to claim 1 or 2. [Function] The lens-integrated projection tube of the present invention allows air inside the air chamber or outside air to pass through the holes of the continuous porous member covering the opening of the air chamber to absorb changes in the volume of the cooling liquid due to changes in the temperature of the projection tube. As a result, the internal pressure of the optical coupling section becomes equal to the external pressure, which is atmospheric pressure, so there is no possibility of damage to the optical coupling section or leakage of coolant. is prevented. Furthermore, since the projection type receiver of the present invention has the above-mentioned lens-integrated projection tube, it is possible to prevent the temperature rise of the fluorescent screen of the projection tube and improve the brightness of the image enlarged and projected on the screen. At the same time, reflection of light generated on the face plate of the projection tube or the surface of the projection lens can also be prevented, and the image image image quality can also be improved. rEmbodiment J Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the lens-integrated projection tube of the present invention. In the lens-integrated projection tube of this embodiment, the projection tube 1, the lens 5 for enlarging and projecting the image of the projection tube 1, and the projection lens group 6 are equipped with a cooling liquid 2 (with high transmittance and good thermal conductivity). For example, an aqueous solution of ethylene glycol, etc.) is integrated through an optical coupling part filled with the liquid. The above-mentioned optical coupling part is provided with heat dissipation fins (not shown),
In addition, there is an aluminum bracket 4 which has been subjected to anti-reflection black alumite treatment, and an aluminum bracket made of nitrile rubber, silicone rubber, etc., which is disposed between the bracket 4, the projection tube 1, and the lune 5, respectively. As shown in FIG. 2, two continuous porous membranes 8a and 8b, through which gas can flow, are formed in a portion of the bracket 4 corresponding to the upper part of the lens-integrated projection tube. A hollow air chamber 7 having an open section 9 covered with a continuous porous member 8 is provided in communication with the optical coupling section. The continuous porous membranes 8a and 8b each have a thickness of 0.1
It is a continuous porous material with an average pore diameter of 1 to 3 mml and an average pore diameter of 1 to 10 μl, and is made of porous tetrafluoroethylene resin (e.g., Boaflon trade name, manufactured by Sumitomo Electric Industries, Ltd.), and each The adhesive or clamp is attached to the opening 9 of the air chamber 7 without any gaps by means of a ring or the like. Next, the operation of this embodiment will be explained. The screen size of the projection tube l is about a finch (approximately 18 cm), the temperature t + = 20°C, the pressure P = 1 atm (103
The volume V of the cooling liquid 2 at 3.6 g/cm") is 20
The liquid level of the cooling liquid 2 in FIG. 1 described above, which is 0 [c31, represents this state. Also, coolant 2
The volumetric expansion coefficient β is 0.7
℃, the body MV of the cooling liquid 2 at that time is determined as follows. V R”V l (l+β(t H−t + ))
=200 x (1+Q, 1 xlO−”x (50−
200=204.2 [c■31 In this way, the volume of the cooling liquid 2 increases as the temperature rises, and the liquid level rises to the inside of the air chamber 7, as shown in FIG. Therefore, the size of the air chamber 7 is the increase in volume AV = V2 - V, = 4.2 [
It will suffice if it can accommodate t, t cm'l. When the liquid level of the coolant 2 rises, the air in the air chamber 7 flows out through the continuous pores of the continuous porous member 8 covering the opening 9, so that the volume change of the coolant 2 is caused by the change in the volume of the coolant 2. 7, and the internal pressure of the optical coupling part is kept constant. Subsequently, when the supply of power to the projection tube 1 is stopped, the temperature of the cooling liquid 2 also decreases as the temperature of the projection 'lit decreases. Assuming that the temperature of this coolant 2 returns to 20°C,
In this case, contrary to the above-mentioned temperature rise case, the volume of the cooling liquid 2 decreases, so that the liquid level becomes as shown in FIG. 1 mentioned above. As the liquid level of the coolant 2 falls, outside air flows into the air chamber 7 through the continuous pores of the continuous porous member 8, so that the internal pressure of the optical coupling portion is similarly maintained constant. Even if the device is tilted or vibrates and the cooling liquid 2 comes into contact with the continuous porous member 8 of the air chamber 7, the cooling liquid 2 will be repelled, return to the optical coupling part, and flow out of the air chamber 7. There isn't. By forming a continuous porous member by doubling continuous porous membranes as in this embodiment, the continuous porous member has strength that can withstand sudden pressure changes in the optical coupling portion. Next, another embodiment of the present invention will be described with reference to FIG. In the embodiment described above, the open [1] covered with the continuous porous member 8 is
In this embodiment, the upper part of the air chamber 47 formed in the lens-integrated projection tube is bent at a predetermined angle of inclination, and the part 9 is provided at the upper end of the air chamber 7. An opening 49 is provided, and the opening 49 is covered with a continuous porous member 48 having the same structure as described above. In the case of this embodiment as well, the internal pressure of the optical coupling part can be kept constant even when the volume of the cooling liquid 420 inside the optical coupling part changes, and even when the cooling liquid 42 comes into contact with the continuous porous member 48, the internal pressure can be kept constant. The liquid 42 is repelled by the continuous porous member 48 and returns into the optical coupling part along the inclined surface.Furthermore, according to this embodiment, it is difficult for foreign matter such as dust to adhere to the continuous porous member 48 ( This prevents the air from being unable to flow due to pore clogging, etc.Also, in each of the above-mentioned examples, the average pore diameter of the two continuous porous membranes constituting the continuous porous member was made uniform; The average pore diameter of the continuous porous membrane is, for example, 0.5 to 3[
μ■1. The average pore diameter of the outer continuous porous membrane is 5 to 10 [L].
Lsl, each having a different pore size may be used. In this case, since the pore size of the inner continuous porous membrane is small, it becomes more difficult for the cooling liquid to flow out. Furthermore, in each of the above-described embodiments, by using a water-repellent material for the continuous porous member, there is no possibility that the cooling liquid of the optical coupling portion will seep into the continuous porous member. Next, a fifth embodiment of the projection type receiver of the present invention will be explained.
This will be explained with reference to the figures. FIG. 5 shows the projection type receiver of this embodiment.
is its front view, and +B) is its side view. This projection type receiver has a cabinet 51 with a screen 52 attached to the front, and a cabinet 51 having the same configuration as described above.
Three lens-integrated projection tubes 54 for red, green, and blue (only one is shown in the figure) and a reflector that reflects the light projected from these lens-integrated projection tubes 54 toward the screen 52. 6 Red projected from each of the three lens-integrated projection tubes 54, which is equipped with a mirror 53! ! , blue image lights are each reflected by a reflecting mirror 53 and then superimposed on a screen 52 to form a color image. In this way, by using the lens-integrated projection tube 54 according to the present invention as described above as a projection tube in a projection-type receiver, the projection tube can be reduced as the temperature of the coolant of the lens-integrated projection tube 54 increases. Since damage to the O-ring and the like and leakage of the coolant can be prevented, an image with high brightness and good contrast can always be stably displayed on the screen 52. [Effects of the Invention] As explained above, the present invention provides the following effects. (1) Changes in the volume of the coolant due to changes in the temperature of the projection tube,
Since the air is absorbed in an air chamber having an opening covered with a continuous porous member, it is possible to maintain a constant internal pressure at the optical coupling part between the projection tube and the projection lens, and at the optical coupling part. Damage to the projection tube, projection lens, and seal portion and leakage of coolant are prevented. (2) The air chamber that absorbs changes in the volume of the coolant is hollow and has an opening covered with a continuous porous member, so it has a simple structure and can be easily manufactured;
It is also economically advantageous. (3) Even if cooling water reaches the opening of the air chamber due to tilting or vibration of the device, the opening is covered with a continuous porous member, so the cooling liquid will flow out to the outside. This means that the coolant returns to the optical coupling part without any problem, and there is no abnormal temperature rise due to lack of coolant. In addition, if a water-repellent material is used as the continuous porous member, the cooling liquid will not penetrate into the continuous porous member, and the effect will be significant. (4) Air chamber Since the opening is covered with a continuous porous member, it is possible to prevent foreign matter such as dust from entering the optical coupling part between the projection tube and the projection lens, and thereby the lens-integrated projection tube of the present invention (5) According to the projection receiver using the lens-integrated projection tube of the present invention, it is possible to always project a clear image on the screen. Breakage of the optical coupling section or leakage of the coolant at the optical coupling section due to temperature rise in the projection tube is eliminated, and the temperature rise at the optical coupling section is suppressed, so that the projected image can be made to have high brightness.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the lens-integrated projection tube of the present invention, FIG. 2 is a cross-sectional view showing the air chamber 7 of FIG. 1, and FIG.
The figure is a cross-sectional view showing a case where the volume of the cooling liquid 2 shown in FIG. 1 changes. FIG. 4 is a cross-sectional view showing another embodiment of the lens-integrated projection tube of the present invention. FIG. An example of a projection type receiver having a body type projection tube is shown, and (A) is a front view. +B) is a side view thereof, and FIG. 6 is a sectional view showing a conventional lens-integrated projection tube. 1.41... Projection tube, 2.42... Coolant. 3.43--0 ring, 4.44--bracket, 5.45--th lens, 6.46--projection lens group, 7.47--air chamber. 8.48... Continuous porous member, 9.49... Opening, 51... Cabinet, 52... Screen, 53... Reflection mirror 54... Lens-integrated projection tube. Listening scale figure 9! Jllo? Figure Figure Buubushito

Claims (1)

[Claims] 1. In a lens-integrated projection tube in which a projection tube and a projection lens are integrated through an optical coupling portion filled with a cooling liquid, an opening covered with a continuous porous member is provided. A lens-integrated projection tube, characterized in that a hollow air chamber having a hollow air chamber is provided in communication with the optical coupling section. 2. The lens-integrated projection tube according to claim 1, wherein the continuous porous member has water repellency. 3. A projection type receiver comprising the lens-integrated projection tube according to claim 1 or 2.