JPH0422041A - Cathode-ray tube projector and cooling liquid used therefor - Google Patents

Abstract

PURPOSE:To prevent the whitening of a plastic lens and the deterioration in optical function due to coloring and the like of a cooling liquid even when used for a long time by using a cooling liquid comprising ethylene glycol, triethylene glycol as well as glycerine. CONSTITUTION:A cooling liquid comprising ethylene glycol, triethylene glycol, and glycerine, is used. Since the viscosity of ethylene glycol is low, while hygroscopicity thereof is large, bad effect such as whitening of lens is expected when it is used individually. The hygroscopicity of triethylene glycor is low for polyor, however, when it is used individually, a plastic lens is whitened, since it has affinity with plastic. Since glycerine is high in the refractive index, it is useful because the reflection loss at the boundary surface between the lens that is in contact with a cooling liquid and the glass of a cathode-ray tube becomes small, however, viscosity is extremely high. When these three materials are mixed with each other into a ternary mixed liquid, the balance between hygroscopicity and affinity becomes good, and excellent low hygroscopicity is obtained, and the whitening of plastic lens or the deterioration in optical function due to the coloring and the like of the cooling liquid is thus prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cathode ray tube projection device and a cooling liquid used therein. More specifically, the present invention relates to an inexpensive cathode ray tube projection device that has excellent optical performance such as brightness and contrast for use in a color glodiector and the like, and whose optical performance does not deteriorate even when used for a long time.

(Prior art) Conventionally, as an electrode ray tube projection device that cools a cathode ray tube with a cooling liquid, as described in 1% Patent Application Publication No. 16524/1983, a cathode ray tube is maintained at a required distance from the entire panel of the cathode ray tube. A lens (incidence lens) facing the front panel is provided in a sealed gap between the lens and the front panel;
A non-aqueous transparent liquid sealed as a cooling liquid (refrigerant liquid) was used. As this non-aqueous coolant.

A single solution or a two-component mixed solution of ethylene glycol, 1,3-butylene glycol, and glycerin is known, and it is known that a plastic lens is preferable for this lens.

(Problems to be Solved by the Invention) As a cooling liquid, a two-component mixture of 1,3-butylene glycol/glycerin and a two-component mixture of ethylene glycol/glycerin have low viscosity and are excellent in cooling efficiency due to convection. However, 1,3-butylene glycol has a high affinity with plastic lenses and causes them to whiten.

This was considered to be a problem because it tends to deteriorate the lens function. Ethylene glycol and glycerin tend to absorb moisture, so moisture absorption causes the refractive index to shift toward a lower value, increasing the difference in refractive index from that of the plastic lens, which tends to reduce the performance of the entire optical system. Plastic lenses tend to whiten when used for a period of time, which was considered a problem.

The present invention overcomes the problems of the prior art described above, has excellent cooling performance, does not cause whitening of plastic lenses or deterioration of optical performance due to coloring of the coolant, etc. even after long-term use, and can be applied to full-surface panels and plastic lenses. The present invention provides an excellent cathode ray tube projection device using a specific cooling liquid having a similar refractive index.9 The present invention also provides the above-mentioned specific cooling liquid.

(Means for Solving Problem A) The present invention is a cathode ray tube projection device that cools a cathode ray tube with a cooling liquid, which uses ethylene glycol.

The present invention relates to a cathode ray tube projection device characterized in that it uses a cooling liquid made of triethylene glycol and glycerin.

Further, the present invention relates to a cooling liquid for cooling a cathode ray tube of a cathode ray tube projection device, which comprises ethylene glycol, triethylene glycol, and glycerin.

Ethylene glycol has a low viscosity and is useful in terms of cooling efficiency, but it is highly hygroscopic, so if ethylene glycol is used alone as a cooling liquid.

The refractive index of the coolant decreases and reflection loss at the interface between the lens and the glass of the cathode ray tube increases. This may cause negative effects such as whitening of the lens.

Triethylene glycol has low hygroscopicity among polyols. However, if triethylene glycol is used alone as a coolant, it will whiten plastic lenses due to its affinity with plastics.

Because glycerin has a high refractive index, it is useful because it reduces reflection loss at the interface between the lens and cathode ray tube glass that comes into contact with the coolant, but glycerin has a very high viscosity when used alone as a coolant. There are drawbacks.

A two-component mixture of triethylene glycol/ethylene di-1-nocol, a two-component mixture of triethylene glycol/glycerin, or a two-component mixture of ethylene glycol/glycerin also whitens plastic lenses.
Furthermore, the viscosity of the coolant increases, resulting in a decrease in cooling efficiency.

When the coolant is a three-component mixture of ethylene glycol/triethylene glycol/glycerin (hereinafter simply referred to as the three-component mixture), the hygroscopicity and affinity are balanced, so plastic lenses do not whiten. , and has excellent low moisture absorption.

Since the amount of change in refractive index due to moisture absorption is small, good optical performance can be maintained even after long periods of use.

The three-component liquid mixture that is the cooling liquid is ethylene glycol #20.
~60]ii%, triethylene glycol 20-40%, and glycerin 20-40%.

The three-component mixed liquid, which is a cold part liquid, has a temperature of 50 (C8t) at 30'C.
) or less, a refractive index (nD) of 1.44 or more (under 30°C conditions) and/or a moisture absorption rate of 0.2% or less (when left in an atmosphere of 65% Rh at 25°C for 7 days) of 69 is preferable. Yes.

In addition, the 3-component mixture g, which is the cold part liquid, contains Nrinine resin,
Since the primary adhesive such as styrene-butane rubber, ac-1-noronide true-butadiene rubber, and ethylene-propylene rubber comes into contact with packing materials and adhesives such as aluminum, it is preferable to use an adhesive that does not corrode or corrode these materials.

One aspect of the inventive cathode ray tube projection device will be explained with reference to FIG. 1 (front view) and FIG. 2 (schematic view of one plane with a part of the front section taken as a cross section).

l is a cathode@tf body, la is a front panel of the negative electrode @tf body, 2 is an entrance lens, and 3 is a ring-shaped spacer, which regulates the distance between the entire surface panel Ia and the entrance lens 2. It is also a member that radiates heat.

4ii is a tongue piece for mounting the cathode ray tube tube body 1, and 5 is a hole through which a mounting screw or the like is inserted, which is bored in the tongue piece.

6 is an adhesive for fixing the spacer 3, and 7 is a gap in which the cooling liquid 8 is sealed. The void 7 has a concave lens shape,
The incident lens 2 is a thin lens with a substantially uniform thickness. Further, since the space in the spacer 3Fi has a concave lens shape, the spacer 3Fi has a thick wall. Note that a pressure relief (not shown) may be provided to absorb the thermal expansion of the cooling liquid 8.

Next, the materials will be explained. When used in a color glow detector, K provides practical brightness.

The temperature of the front panel 1a increases to 90° C. or higher. Furthermore, the environmental temperature in which the device is used may be 0° C. or lower.

Coolant 8 must be a coolant consisting of ethylene glycol, triethylene glycol and glycerin.

For the entrance lens 2, polymethyl methacrylate can be used. Other lens materials include polycarbonate,
Any transparent plastic such as polystyrene or diglycol diallyl carbonate polymer can be used, but in view of the fact that the temperature of the cooling liquid 8 in contact reaches 80°C or higher and the cost of materials, it is preferable to use polymethyl methacrylate or polycarbonate. . The spacer 3 is made of metal to provide a heat dissipation effect.

Preferably, it is made of aluminum, which has high thermal conductivity. Adhesive 6Fi resin can be used.

Silicone resins are preferably used.

The operation of the cathode ray tube projection apparatus having the above configuration will be explained.

During use, the temperature of the front panel 1a of the cathode ray tube rises to 90° C. or higher. The coolant 8 removes heat from it and cools it. At that time, the temperature of the coolant 8Fi rises to around 80°C. The heat accumulated in the coolant 8 is transferred to the air outside the cathode ray tube through the spacer 3, which has a heat dissipation function. At this time, the entrance lens 2
is heated to about 70°C.

(Example) The present invention will be explained below with reference to Examples.

Examples 1-3. Comparative Examples 1 to 4 A cooling liquid was prepared by mixing ethylene glycol, triethylene glycol, and glycerin in the proportions shown in Table 1 or Table 2, and the transmittance, refractive index, viscosity, moisture permeability,
The plastic resistance was measured and the results are shown in Table 1 or Table 2.
It was shown to.

Transmittance: Transmittance at 400 (nm) was measured using a n1 spectrophotometer (■Hitachi Layer 228 Al) with mixed g added to a quartz cell.

Refractive index: D at 30°C with Atsbe refractometer (manufactured by Atago)
The refractive index was measured.

Viscosity: Viscosity was measured at 30°C using an Ubbelohde viscometer.

Moisture absorption rate: 11! Pour 500ml of coolant into the Hiro Robin.

The sample was left open for 7 days at 25° C. under a 65-degree Rh atmosphere, and the moisture content was measured using a Karl Fischer moisture meter (Mitsubishi Kasei MCI-CA 02 model).

Plastic resistance: A cooling liquid was sealed in the cavity 7 of the cathode M tube dosing device shown in FIGS. 1 and 2, and the device was operated for 7 days. At that time, the temperature of the cooling liquid rose to around 90° C.).

After that, the input lens 2 becomes white. Visually observe whether the input lens 2 is polymethyl methacrylate.

Spacer 3, aluminum, adhesive Silicone resin gold was used as No. 6).

(Effects of the Invention) By using the coolant made of ethylene glycol, triethylene glycol, and glycerin according to the present invention, it has excellent cooling performance, and even after long-term use, the optical It is possible to provide an excellent cathode ray tube projection device in which the performance does not deteriorate and the cooling liquid has a refractive index close to that of a plastic lens.

The cathode ray tube device of the present invention is suitable for a color glodictor and the like.

[Brief explanation of the drawing]

FIG. 1 is a front view of a cathode ray tube projection device used in an embodiment according to one aspect of the present invention, and FIG. 2 is a schematic side view of the same device. Explanation of symbols

Claims (1)

[Scope of Claims] 1. A cathode ray tube projection apparatus, which is a cathode ray tube that is cooled by a cooling liquid, and is characterized in that the cooling liquid is made of ethylene glycol, triethylene glycol, and glycerin. 2. A cathode ray tube projection apparatus according to claim 1, wherein the cooling liquid comprises 20 to 60% by weight of ethylene glycol, 20 to 40% by weight of triethylene glycol, and 20 to 40% by weight of glycerin. 3. A cooling liquid for cathode ray tubes in cathode ray tube projection devices, which is composed of ethylene glycol, triethylene glycol, and glycerin. 4. Ethylene glycol 20-60% by weight, triethylene glycol 20-40% by weight and glycerin 20-4
Coolant according to claim 3, comprising 0% by weight.