CA1274577A - Liquid-cooled display tube with counter direction coolant flow - Google Patents
Liquid-cooled display tube with counter direction coolant flowInfo
- Publication number
- CA1274577A CA1274577A CA000513394A CA513394A CA1274577A CA 1274577 A CA1274577 A CA 1274577A CA 000513394 A CA000513394 A CA 000513394A CA 513394 A CA513394 A CA 513394A CA 1274577 A CA1274577 A CA 1274577A
- Authority
- CA
- Canada
- Prior art keywords
- window
- display
- space
- cooling
- liquid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J7/00—Details not provided for in the preceding groups and common to two or more basic types of discharge tubes or lamps
- H01J7/24—Cooling arrangements; Heating arrangements; Means for circulating gas or vapour within the discharge space
- H01J7/26—Cooling arrangements; Heating arrangements; Means for circulating gas or vapour within the discharge space by flow of fluid through passages associated with tube or lamp
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
- H01J29/006—Arrangements for eliminating unwanted temperature effects
Landscapes
- Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
- Transforming Electric Information Into Light Information (AREA)
- Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
- Liquid Crystal (AREA)
- Common Detailed Techniques For Electron Tubes Or Discharge Tubes (AREA)
Abstract
PHN. 11.441 ABSTRACT:
In a known display tube, in particular for projection television, cooling is used by causing a cooling liquid to flow laminarly between the display window and a second window. An important improve-ment of the cooling is obtained according to the invention by cooling the heated cooling liquid in a cooling system beyond the light path and returning it via a space between the second window and a third window to the space between the display window and the second window.
In a known display tube, in particular for projection television, cooling is used by causing a cooling liquid to flow laminarly between the display window and a second window. An important improve-ment of the cooling is obtained according to the invention by cooling the heated cooling liquid in a cooling system beyond the light path and returning it via a space between the second window and a third window to the space between the display window and the second window.
Description
~Z7457~
The invention relates to a display tube comprislng an evacuated envelope haviny a display window which on its inside comprises a display screen and in front of whlch on its outside a transparent second window is provided substantially parallel to the display window and with a space between the display window and the second window which is destined for lamlnar flow of a transparent cooling liquid.
Such a dlsplay tube is disclosed in Canadian Patent 1,218,404 - Gerritsen et al - issued February 24, 1987 (P~N
10,547).
Coollng of display tubes i~ of particular importance in dlsplay tubes for projection television, in which for obtaining the required great brightnesses the display 6creens are scanned by electron beams with high beam currents.
The use of a laminar flow of cooling liquid prevents inhomogeneitles occurring ln the coollng liquid and hence dlfference~ in refractlve lndlces whlch are expressed as refractlve patterns in the dlsplayed plcture.
For that purpose the spaclng between the display wlndow and the second wlndow generally ls approxlmately 3 to 4 mm.
Although good results are obtalned wlth the above-mentloned dl#play tube, lt has been found that lmportant improvements are possible. These relate to the improvement of the flow of coollng llquld through the space between the dlsplay wlndow and the second wlndow and the slmpllficatlon of the con~truction ~o that fewer components and a simpler assembly and dl~as~embly of the tube become posslble.
C
., , ' . ' ~' : . . -~2~4S7'7 One of the objects of the invantion is to achieve the said improvements at least to a considerable extent~
Therefore, the display tube mentioned in the opening paragraph is characterized according to the invention in that B la ' ~ ' ~Z74577 PHN.11.441 2 15.11,85 a third window is provided substantially parallel to and in front of the side of the second window remote from the display window, said third window forming with the second window a second space containing the cooling liquid, the 5 second space communicating with the first mentioned space beyond the light path o~ the display tube, and in that a closed cooling system is provided beyond said light path, the cooling system communicating with said first mentioned and said second spaces whereby the transparent cooling 10 fluid in said second space flows in counter current to the liquid in the first mentioned space.
In a display tube according to the invention, the cooling system and the second window can particularly simply be assembled and disassembled due tothe absence 5 of hoses, pumps and associated arrangements, while the closed cooling system proves to provide a cooling which is suffi-ciently large to use the display tube at substantially any suitable angle.
By using a closed cooling system behond the light 20path no glass components need be used in the light path but, for example, a synthetic resin may be used for the second and the third window and metal components may be used in the cooling system.
In a preferred embodiment of the display tube in 25accordance with the invention, the third window is a part of a system of lenses.
This construction promotes a rapid and accurate positioning of the display tube with respect to the system of lenses. Optimum results are obtained with optical coupling 30Of the windows and the cooling liquid. For that purpose, the refractive indices of the cooling liuquid and of the display window and the second and third windows are adapted to each other.
The invention will now be described in greater 35detail, by way of example, with reference to the single figure of the accompanying drawing, which figure is a diagrammatic sectional view of a display tube according to the invention.
.
. ~, ' ' ~.
- ~ ' ' ' ~ ' ' : . . ' ' .' , ' . -~27~57~
PHN.11.441 3 15.11.85 The display tube comprises an evacuated envelope 1 having a substantially rectangular display window 2 which comprises a display screen 3 on its inside and in front of which on its outside a transparent second window 4 is pro-5 vided so as to be substantially parallel with the outsideand having a space 5 between the display window 2 and the second window 4 which space is destined for laminar flow of a transparent liquid.
The flow of the transparent liquid through the lO space 5 in a display tube according to the invention is considerably improved in that beyond the light path of the display tube a closed cooling system 6, which may comprise a heat exchanger, is provided for cooling, beyond the light path, the cooling liquid heated during operation of the 15 display tube. Moreover, in front of the side of the second window 4 remote from the display window 2 a third window 7 is provided substantially parallel to the remote side and with the second window 4forms a second space 8 to return, in counter current with respect to the heatedliquid, the 20 cooled cooling liquid to the first space 5 between the display window 2 and the second window 4. The first and second spaces 5, 8 communicate with each other beyond the light path of the display tube. The flow of the cooling liquid is indicated by the arrows. If the cooling system 6 25 does not comprise a pump then the liquid flow is by convection.
The third window 7 preferably is a part of a system of lenses.
The spacing between the display window 2 and the 30 second window 4 is 3 to 4 mm. The spacing between the second window 4 and the third window 7 is also 3 to 4 mm.
The cooling system 6 may be of metal, for example, aluminium, which enables a good cooling in a simple manner.
The windows 4 and 7 may be of a synthetic resin, for example, 35polymethylmethacrylate, the refractive index of which corresponds to that of a cooling liquid consisting of a solution of glycol in water. In this manner an optical coupling between structural materials and cooling liquid - lZr~S;77 PHN.11.441 4 15.11.~5 is produced in a simple manner, so that annoying reflections are avoided. The cooling in the display tube according to the invention is so good that the angle at which the display tube is used is of at most minor influence on the cooling.
In an exemplary embodiment of a display tube having a power of 30 W and a room temperature of 20 C, the rise in temperature uf t~e cooling liquid was at most 40 C.
This rise in temperature stabilised itself after 2 hours.
The assembly and disassemblyof the cooling system is very simple, as well as the positioning with respect to the system of lenses.
It will be obvious that the invention is not restricted to the example described, but that many variation possibilities are available to those skilled in the art without departing from the scope of the present invention.
' ' ' ' ' .-' ' , :
,
The invention relates to a display tube comprislng an evacuated envelope haviny a display window which on its inside comprises a display screen and in front of whlch on its outside a transparent second window is provided substantially parallel to the display window and with a space between the display window and the second window which is destined for lamlnar flow of a transparent cooling liquid.
Such a dlsplay tube is disclosed in Canadian Patent 1,218,404 - Gerritsen et al - issued February 24, 1987 (P~N
10,547).
Coollng of display tubes i~ of particular importance in dlsplay tubes for projection television, in which for obtaining the required great brightnesses the display 6creens are scanned by electron beams with high beam currents.
The use of a laminar flow of cooling liquid prevents inhomogeneitles occurring ln the coollng liquid and hence dlfference~ in refractlve lndlces whlch are expressed as refractlve patterns in the dlsplayed plcture.
For that purpose the spaclng between the display wlndow and the second wlndow generally ls approxlmately 3 to 4 mm.
Although good results are obtalned wlth the above-mentloned dl#play tube, lt has been found that lmportant improvements are possible. These relate to the improvement of the flow of coollng llquld through the space between the dlsplay wlndow and the second wlndow and the slmpllficatlon of the con~truction ~o that fewer components and a simpler assembly and dl~as~embly of the tube become posslble.
C
., , ' . ' ~' : . . -~2~4S7'7 One of the objects of the invantion is to achieve the said improvements at least to a considerable extent~
Therefore, the display tube mentioned in the opening paragraph is characterized according to the invention in that B la ' ~ ' ~Z74577 PHN.11.441 2 15.11,85 a third window is provided substantially parallel to and in front of the side of the second window remote from the display window, said third window forming with the second window a second space containing the cooling liquid, the 5 second space communicating with the first mentioned space beyond the light path o~ the display tube, and in that a closed cooling system is provided beyond said light path, the cooling system communicating with said first mentioned and said second spaces whereby the transparent cooling 10 fluid in said second space flows in counter current to the liquid in the first mentioned space.
In a display tube according to the invention, the cooling system and the second window can particularly simply be assembled and disassembled due tothe absence 5 of hoses, pumps and associated arrangements, while the closed cooling system proves to provide a cooling which is suffi-ciently large to use the display tube at substantially any suitable angle.
By using a closed cooling system behond the light 20path no glass components need be used in the light path but, for example, a synthetic resin may be used for the second and the third window and metal components may be used in the cooling system.
In a preferred embodiment of the display tube in 25accordance with the invention, the third window is a part of a system of lenses.
This construction promotes a rapid and accurate positioning of the display tube with respect to the system of lenses. Optimum results are obtained with optical coupling 30Of the windows and the cooling liquid. For that purpose, the refractive indices of the cooling liuquid and of the display window and the second and third windows are adapted to each other.
The invention will now be described in greater 35detail, by way of example, with reference to the single figure of the accompanying drawing, which figure is a diagrammatic sectional view of a display tube according to the invention.
.
. ~, ' ' ~.
- ~ ' ' ' ~ ' ' : . . ' ' .' , ' . -~27~57~
PHN.11.441 3 15.11.85 The display tube comprises an evacuated envelope 1 having a substantially rectangular display window 2 which comprises a display screen 3 on its inside and in front of which on its outside a transparent second window 4 is pro-5 vided so as to be substantially parallel with the outsideand having a space 5 between the display window 2 and the second window 4 which space is destined for laminar flow of a transparent liquid.
The flow of the transparent liquid through the lO space 5 in a display tube according to the invention is considerably improved in that beyond the light path of the display tube a closed cooling system 6, which may comprise a heat exchanger, is provided for cooling, beyond the light path, the cooling liquid heated during operation of the 15 display tube. Moreover, in front of the side of the second window 4 remote from the display window 2 a third window 7 is provided substantially parallel to the remote side and with the second window 4forms a second space 8 to return, in counter current with respect to the heatedliquid, the 20 cooled cooling liquid to the first space 5 between the display window 2 and the second window 4. The first and second spaces 5, 8 communicate with each other beyond the light path of the display tube. The flow of the cooling liquid is indicated by the arrows. If the cooling system 6 25 does not comprise a pump then the liquid flow is by convection.
The third window 7 preferably is a part of a system of lenses.
The spacing between the display window 2 and the 30 second window 4 is 3 to 4 mm. The spacing between the second window 4 and the third window 7 is also 3 to 4 mm.
The cooling system 6 may be of metal, for example, aluminium, which enables a good cooling in a simple manner.
The windows 4 and 7 may be of a synthetic resin, for example, 35polymethylmethacrylate, the refractive index of which corresponds to that of a cooling liquid consisting of a solution of glycol in water. In this manner an optical coupling between structural materials and cooling liquid - lZr~S;77 PHN.11.441 4 15.11.~5 is produced in a simple manner, so that annoying reflections are avoided. The cooling in the display tube according to the invention is so good that the angle at which the display tube is used is of at most minor influence on the cooling.
In an exemplary embodiment of a display tube having a power of 30 W and a room temperature of 20 C, the rise in temperature uf t~e cooling liquid was at most 40 C.
This rise in temperature stabilised itself after 2 hours.
The assembly and disassemblyof the cooling system is very simple, as well as the positioning with respect to the system of lenses.
It will be obvious that the invention is not restricted to the example described, but that many variation possibilities are available to those skilled in the art without departing from the scope of the present invention.
' ' ' ' ' .-' ' , :
,
Claims (2)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A display tube comprising an evacuated envelope having a display window which on its inside comprises a display screen and in front of which on its outside a transparent second window is provided substantially parallel to the display window and with a space between the display window and the second window which is destined for laminar flow of a transparent cooling liquid, characterized in that a third window is provided substantially parallel to and in front of the side of the second window remote from the display window, said third window forming with the second window a second space containing the cooling liquid, the second space communicating with the first mentioned space beyond the light path of the display tube, and in that a closed cooling system is provided beyond said light path, the cooling system communicating with said first mentioned and said second spaces whereby the transparent cooling fluid in said second space flows in counter current to the liquid in the first-mentioned space.
2. A display tube as claimed in claim 1, characterized in that the third window forms part of a system of lenses.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL8501993A NL8501993A (en) | 1985-07-11 | 1985-07-11 | PICTURE TUBE. |
| NL8501993 | 1985-07-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1274577A true CA1274577A (en) | 1990-09-25 |
Family
ID=19846285
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000513394A Expired - Lifetime CA1274577A (en) | 1985-07-11 | 1986-07-09 | Liquid-cooled display tube with counter direction coolant flow |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0209191B1 (en) |
| JP (1) | JPS6215729A (en) |
| KR (1) | KR930010599B1 (en) |
| CA (1) | CA1274577A (en) |
| DE (1) | DE3670724D1 (en) |
| ES (1) | ES2000473A6 (en) |
| NL (1) | NL8501993A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3418486B2 (en) * | 1994-09-06 | 2003-06-23 | 成興工業株式会社 | Height-adjustable folding chair |
| ES2113321B1 (en) * | 1996-06-07 | 1999-01-16 | Sony Corp | CATHODIC RAY TUBE OF THE LIQUID REFRIGERATION TYPE. |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0111979B1 (en) * | 1982-12-22 | 1987-03-18 | Philips Electronics Uk Limited | Means for cooling the faceplate of a cathode ray tube in a television projection system |
| NL8300114A (en) * | 1983-01-13 | 1984-08-01 | Philips Nv | PICTURE TUBE. |
| JPS59157938A (en) * | 1983-02-24 | 1984-09-07 | Sony Corp | Cathode ray tube device |
| JPH07118260B2 (en) * | 1985-06-25 | 1995-12-18 | ソニー株式会社 | Cathode ray tube device |
-
1985
- 1985-07-11 NL NL8501993A patent/NL8501993A/en not_active Application Discontinuation
-
1986
- 1986-07-08 ES ES8600184A patent/ES2000473A6/en not_active Expired
- 1986-07-08 KR KR1019860005488A patent/KR930010599B1/en not_active IP Right Cessation
- 1986-07-08 EP EP86201199A patent/EP0209191B1/en not_active Expired - Lifetime
- 1986-07-08 DE DE8686201199T patent/DE3670724D1/en not_active Expired - Lifetime
- 1986-07-09 JP JP61159877A patent/JPS6215729A/en active Pending
- 1986-07-09 CA CA000513394A patent/CA1274577A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| NL8501993A (en) | 1987-02-02 |
| DE3670724D1 (en) | 1990-05-31 |
| ES2000473A6 (en) | 1988-03-01 |
| KR930010599B1 (en) | 1993-10-30 |
| EP0209191A1 (en) | 1987-01-21 |
| EP0209191B1 (en) | 1990-04-25 |
| JPS6215729A (en) | 1987-01-24 |
| KR870001631A (en) | 1987-03-17 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |