JPH03241641A - Lens-integrated projection picture tube and projection type picture tube with same lens-integrated projection picture tube - Google Patents

Abstract

PURPOSE:To keep the internal pressure of an optical connection section by adjusting the cooling liquid pressure to match the preset liquid pressure. CONSTITUTION:When temperature rises and the volume of a cooling liquid 7 is expanded and the liquid pressure becomes larger than the preset liquid pressure, a pinion 23 is rotated counterclockwise, a rack 22 is moved to the right, a piston 32 is moved to the right, the volume of a pressure adjusting chamber 33 is increased, and the cooling liquid pressure is returned to the preset pressure. When temperature is lowered and the pressure of the cooling liquid 7 becomes smaller than the preset liquid pressure, the pinion 23, rack 22 and piston 32 are all moved in the opposite direction to the above, the volume of the chamber 33 is decreased, and the liquid pressure is returned to the preset liquid pressure. The pressure of the cooling liquid 7 is invariably detected by a pressure sensor 10, feedback control is performed to correctly match the liquid pressure with the preset liquid pressure, thus the internal pressure of an optical connection section can correctly be kept at the preset pressure.

Description

Detailed Description of the Invention [Field of Industrial Application] 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. .

[Conventional technology]

Conventionally, in a projection type receiver that uses a projection tube to project an enlarged image onto a screen, a lens-integrated projection tube is used in which the lens and the projection tube are optically coupled by a cooling liquid in order to improve the brightness and contrast of the image. (Denshi Gijutsu Publishing “Television Technology J Vol. 34. P. 28~
P, 31.1986).

FIG. 7 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 68 and lens group 66 (some lenses are omitted), an aluminum bracket 65 that is provided with heat dissipation fins (not shown) and is treated with anti-reflection black alumite, and a nitrile An O-ring 64 made of rubber, silicone rubber, etc., and a projection tube 61. Runs 68
．． 0 ring 64. A cooling liquid 67 (for example, an aqueous solution of ethylene glycol, etc.) having high light transmittance and good thermal conductivity is filled in the space sealed by the bracket 65 (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 67, 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. Further, the reflection of light that occurs on the surfaces of the face plate of the projection tube 61 and the second lune 68 can be prevented by making the refractive index of the coolant 67 approximately equal to the refractive index of the face plate and the second lune 68. I'm trying to improve the contrast.

However, in this lens-integrated projection tube, when the volume of the cooling liquid 67 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 ring 64, leakage of the coolant 67, and air suction.

In order to compensate for this drawback, 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 second lun, and the cooling liquid is attached to the side of the transparent resin bag. An elastic bag is provided to allow for inflow and outflow. 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]

The lens-integrated projection tube described in Japanese Patent Publication No. 63-64115 mentioned above has a method in which a transparent resin bag containing the cooling liquid is glued to the projection tube and the first lens, or the elastic bag is attached to the transparent resin bag. Since it is necessary to provide this, there is a drawback that the manufacturing process of the optical coupling portion becomes complicated.

Further, since the lens-integrated projection tube described in the above-mentioned Japanese Utility Model Application Publication No. 62-103154 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.

[Failure to solve the problem]

The lens-integrated projection tube of the present invention includes a pressure regulating means provided in a part of a bracket constituting an optical coupling part filled with a cooling liquid, and a pressure sensor for detecting the liquid pressure of the cooling liquid in the optical coupling part. and a control unit that compares the output signal of the pressure distribution sensor with a preset liquid pressure of the coolant and causes the pressure adjustment means to adjust the pressure so that the two match.

Further, according to claim 2, a projection type receiver of the present invention includes the lens-integrated projection tube.

[Effect]

In the lens-integrated projection tube of the present invention, even if the volume of the coolant filled in the optical coupling section changes due to a temperature change and the pressure of the coolant changes, the pressure sensor detects the pressure of the coolant. When detected, the control unit causes the pressure regulating means to adjust the pressure of the coolant so that it matches a preset set pressure of the coolant, so that the hydraulic pressure of the coolant, that is, the optical coupling The internal pressure of the part is always kept constant.

Furthermore, since the projection type receiver according to claim 2 has the above-mentioned lens-integrated projection tube, it is possible to prevent the temperature rise of the phosphor screen of the projection tube mentioned above, and to reduce the brightness of the image enlarged and projected on the screen. In addition, it is possible to prevent the reflection of light occurring on the surfaces of the face plate and the first lens of the projection tube, and to improve the contrast of the image.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing the main parts of a first embodiment of the lens-integrated projection tube of the present invention, FIG. 2 is a view showing an example of the configuration of the pressure sensor 10 shown in FIG. 1, and FIG. FIG. 4 is a diagram showing a control system of the pressure regulating means 30 shown in the figure, and FIG. 4 is a diagram showing another example of the configuration of the pressure sensor 10 shown in FIG.

The lens-integrated projection tube of this embodiment includes a projection tube 1, a lens 8 for enlarging the image of the projection tube 1, and a lens group 6 (some lenses are omitted), and the optical coupling portion of these , an aluminum bracket 5 provided with heat dissipation fins (not shown) and subjected to anti-reflection black alumite treatment;
It is composed of the bracket 5, and an O-ring 4 made of nitrile rubber, silicone rubber, etc., which is disposed between the projection tube 1 and the lance 8. And in the optical coupling part,
It is filled with a cooling liquid 7 (for example, an aqueous solution of ethylene glycol) that has high light transmittance and good thermal conductivity, and has a refractive index close to that of glass or plastic.

A pressure regulating chamber 33 that communicates with the optical coupling portion and is filled with the cooling liquid 7 is provided in a part of the bracket 5, and the volume of the pressure regulating chamber 33 is such that the piston 32 moves left and right inside the cylinder 31. It can be changed by That is, cylinder 31. The piston 32 and the pressure regulating chamber 33 act as pressure regulating means 30 for the internal pressure of the optical coupling section. The piston 32 is provided with an O-ring (not shown) made of nitrile rubber, silicone rubber, etc., to prevent liquid leakage from the contact area between the piston 32 and the cylinder 31.

As driving means for the piston 32, a power source 25 (see FIG. 3) and an arm 21. Rack 22. A power transmission means 20 consisting of a pinion 23 is provided. Here, the pinion 23 is connected to a power source 25, the rack 22 is attached to the arm 21 so as to mesh with the pinion 23, and one end of the arm 21 is attached to the piston 32.

A bracket 5 that communicates the optical coupling portion and the pressure regulating chamber 33.
A pressure sensor 10 is provided in a part of the pressure sensor 10, and the output signal of the pressure sensor 10 is transmitted to an amplifier 41. as shown in FIG.
A/D converter 42. Microprocessor 43. Memory 44. Control unit 4 consisting of interface 45
0 is man-powered. Further, the control unit 40 controls the power source 25.

Next, the configuration of the pressure sensor 10 will be explained in detail using FIG. 2.

The pressure sensor 10 is a known silicon diaphragm type pressure sensor, and includes a metal stem 11, a base 12, and a glass layer 1.
3, a silicon chip 14, a silicon diaphragm 15, and a strain gauge 16.

The liquid pressure P of the coolant 7 applied to the silicon diaphragm 15 (that is, the internal pressure of the optical coupling part) is converted into stress generated in the silicon diaphragm 15 and detected by the strain gauge 16 formed on the silicon diaphragm 15. and output as an electrical signal. The strain gauge 16 has a full bridge connection, and two piezoelectric film resistors laser-trimmed to match the characteristics of each individual element are placed in the center and two on the periphery, and the temperature characteristics, zero level,
Corrections such as span have been made.

Next, the operation of keeping the internal pressure of the optical coupling part constant in the lens-integrated projection tube of this embodiment will be explained with reference to FIG.

An electrical signal corresponding to the liquid pressure P of the coolant 7 output from the pressure sensor 10 is amplified by an amplifier 41, converted to a digital signal by an A/D converter 42, and then input to a microprocessor 43. microprocessor 43
operates according to a program prestored in the memory 44, compares the hydraulic pressure P of the coolant 7 with the set hydraulic pressure of the coolant 7 prestored in the memory 44, and performs stepping so that the two match. A control signal is created to control the rotational direction of the power source 25 consisting of a motor, servo motor, etc. That is, when the hydraulic pressure P of the coolant 7 is greater than the set hydraulic pressure of the coolant 7, the microprocessor 43
A control signal is created to rotate the power source 25 in the direction of rotating the pinion 23 counterclockwise as shown in FIG. A control signal is created to rotate the power source 25 in the opposite direction from before. The control signal is output to the power source 25 via the interface 45.

Therefore, when the temperature rises, the volume of the coolant 7 expands, and the liquid pressure P of the coolant 7 becomes greater than the set liquid pressure of the coolant, the pinion 23 shown in FIG. 1 rotates counterclockwise. Since the rack 22 rotates to the right and moves to the right, the piston 32 also moves to the right and the volume of the pressure regulating chamber 33 increases, so the volumetric expansion of the coolant 7 is absorbed and the liquid pressure of the coolant 7 increases. P returns to the set hydraulic pressure of the coolant. On the other hand, even when the temperature drops and the volume of the coolant 7 contracts and the liquid pressure P of the coolant 7 becomes lower than a predetermined pressure, the rack 22 can be moved to the left by rotating the binion 23 clockwise. direction, the piston 32 also moves to the left, and the pressure regulating chamber 3
3 decreases, the hydraulic pressure P of the coolant 7 similarly returns to the set hydraulic pressure of the coolant.

Here, by constantly detecting the liquid pressure P of the coolant 7 with the pressure sensor 10 and performing feedback control, the liquid pressure P of the coolant 7 can be accurately adjusted to the set liquid pressure of the coolant. The internal pressure of the optical coupling 1 is precisely set to a predetermined pressure (for example, atmospheric pressure).
can be kept.

In addition, in the pressure sensor 10 used in the lens-integrated projection tube of this embodiment, the cooling liquid 7 is directly applied to the silicon diaphragm 1.
5 was pressurized (see FIG. 2), but as shown in FIG.
7 and the silicon diaphragm 115 may be filled with a sealing liquid 118 such as silicone oil, and the silicon diaphragm 115 may be pressurized via the sealing liquid 118. In this case, a wide variety of liquids can be used as the cooling liquid 7.

Further, as a driving means for the piston 32, a fluid pressure cylinder, a cam mechanism, etc. can also be used.

FIG. 5 is an enlarged sectional view of the vicinity of the pressure regulating chamber 273 of the second embodiment of the lens-integrated projection tube of the present invention.

The lens-integrated projection tube of this embodiment is different from the one shown in FIG.

In this embodiment as well, the pressure of the coolant 257 is detected by the pressure sensor 260, and the arm 282 is adjusted based on the output signal of the pressure sensor 260 in the same manner as in the embodiment shown in FIG. By moving laterally, the bellows 272
Since the pressure adjustment chamber 273 also moves in the lateral direction, the volume of the pressure regulating chamber 273 changes and the internal pressure of the optical coupling portion can be kept constant.

FIGS. 6(8) and 6(B) are a front view and a side sectional view, respectively, showing an embodiment of a projection type receiver having a lens-integrated projection tube according to the present invention.

This projection type receiver includes a housing 70, a screen 71 attached to the front of the housing 70, and a projection tube 72 integrated with three lenses for red, green, and blue as shown in FIG. 1 or 5. (
(Only one is shown in the figure) and a mirror 73 that reflects the light projected from the lens-integrated projection tube 72 toward the screen 71.

Each color light indicating the red, green, and blue components of the image projected from each of the three lens-integrated projection tubes 72 is transmitted to the mirror 73.
The color images are reflected on the screen 71 and then superimposed on the screen 71, so that a color image is projected on the screen 71.

By using the lens-integrated projection tube 72 according to the present invention as the projection tube, this projection-type receiver can be used as a projection tube.
This prevents damage to O-rings, coolant leaks, and air intake, ensuring a stable, high-brightness, high-contrast image is always displayed on the screen.

(Effects of the Invention) Since the present invention is configured as described above, it has the following effects.

In the lens-integrated projection tube of the present invention, even if the volume of the coolant filled in the optical coupling section changes due to a temperature change and the pressure of the coolant changes, the pressure sensor detects the pressure of the coolant. When the pressure is detected, the control unit controls the driving means of the member that changes the volume of the pressure regulating chamber so that the liquid pressure of the cooling liquid matches a preset liquid pressure of the cooling liquid. The liquid pressure of the coolant, that is, the internal pressure of the optical coupling part, can be kept constant at all times, the manufacturing process of the optical coupling part can be simplified, and the degree of freedom in designing the projection tube and the second lens can be increased. There is an effect.

In the projection type receiver of the present invention, since the image is projected onto the screen by the lens-integrated projection tube, there is an effect that the brightness and contrast of the image can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the main parts of a first embodiment of the lens-integrated projection tube of the present invention, FIG. 2 is a view showing an example of the configuration of the pressure sensor 10 shown in FIG. 1, and FIG. 4 is a diagram showing another configuration example of the pressure sensor 10 in FIG. 1, and FIG. 5 is a diagram showing a second embodiment of the lens-integrated projection tube of the present invention. An enlarged sectional view of the area around the pressure regulating chamber 273 in the example,
Figure 6 shows a projection type having a lens-integrated projection tube of the present invention.
5 shows an example of a receiver, (A) is a front view thereof, (B)
7 is a side sectional view thereof, and FIG. 7 is a sectional view showing the basic structure of the lens-integrated projection tube. 1.251...Projection tube, 4.254...O ring, 5.255-...Bracket, 6...Lens group, 7.257...Cooling liquid, 8.258...Luns , 10.100,260--Pressure sensor, 11.111
...Metal stem, 12.112--Base, 13.113--Glass layer, 14.114--Silicon chip, 15.115--Silicon diaphragm, 16.11
6... Strain gauge, 20... Power transmission means, 21.282-... Arm, 22-... Rack, 23... Pinion, 25...
・Power source, 30,270...Pressure regulating means, 6 31...Cylinder, 32-...Piston, 33.27
3--Pressure adjustment chamber, 40--Control unit, 41--Amplifier, 42--A/D converter, 43--Microprocessor, 44--Memory, 45--Interface,
70... Housing, 71-... Screen, 72-...
... Lens-integrated projection tube, 73... Mirror 117... Stainless steel diaphragm, 118-... Filled liquid, 272-... Bellow p-... Liquid pressure.

Claims (1)

[Scope of Claims] 1. A pressure regulating means provided in a part of a bracket constituting an optical coupling part filled with a cooling liquid, and a pressure sensor for detecting the liquid pressure of the cooling liquid in the optical coupling part; A lens comprising: a control section that compares the output signal of the pressure sensor with a preset liquid pressure of the coolant and causes the pressure regulating means to regulate the pressure so that the two match. Body projection tube. 2. A projection type receiver having the lens-integrated projection tube according to claim 1.