CN1125479C - Cathode ray tube with beam shielding plate for preventing halation - Google Patents
Cathode ray tube with beam shielding plate for preventing halation Download PDFInfo
- Publication number
- CN1125479C CN1125479C CN 97101893 CN97101893A CN1125479C CN 1125479 C CN1125479 C CN 1125479C CN 97101893 CN97101893 CN 97101893 CN 97101893 A CN97101893 A CN 97101893A CN 1125479 C CN1125479 C CN 1125479C
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- CN
- China
- Prior art keywords
- electron beam
- shielding plate
- ray tube
- cathode ray
- end surface
- 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 - Fee Related
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- 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
- H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
- H01J29/06—Screens for shielding; Masks interposed in the electron stream
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- Electrodes For Cathode-Ray Tubes (AREA)
Abstract
A cathode ray tube is over-scanned. In order to prevent halation in a dark room, a beam shielding plate is shaped so that the front end surface of the beam shielding plate is substantially parallel to a path (E) of the electron beam or so that it is swept back from the path (E) of the electron beam to thereby prevent the electron beam from striking the front end surface of the beam shielding plate, prevent the reflection of the electron beam at the front end surface, and prevent halation.
Description
Technical field
The present invention relates to cathode ray tube, can prevent halation when this cathode ray tube is used for overscanning.
Background technology
As shown in Figure 1, in the color cathode ray tube, on the inner surface of the panel 3 of shell 2, form phosphor screen 4.In the face of phosphor screen 4 is provided with the color selecting pole system 10 that is called hole grid or shadow mask.With the electron beam E that deflection system 6 deflections are launched from the electron gun 5 of the neck 2a that places shell 2, make its scanning phosphor screen 4.
Fig. 2 is the schematic top view of showing colour-selecting mechanism in the cathode ray tube, as shown in Figure 2, cathode ray tube is during as the television monitor in the broadcasting station etc., sometimes overscanning ground uses cathode ray tube, even the outside of the normal active zone that electron beam E scanning is limited by the distal-most end narrow slit of color selecting pole system 10.When overscanning ground used cathode ray tube, the overscanning electron beam was in the framework 11 places deflection brokenly of color selecting pole system.When arriving phosphor screen 4, the electronics of irregular deviation causes framework halation.For this reason, in the television monitor of usefulness such as broadcasting station, between the deflection center DC of framework 11 and electron beam, be provided with the length that is made of metal and thin beam shielding plate 12, on the beam shielding plate 13, make electron beam can not collide framework 11 in this barricade 12 is attached to.Usually these beam shielding plate 12 usefulness iron or stainless steel are made thick about 0.2mm, and its absorbs electronics when adding high voltage, or with electron reflection to electron gun side, thereby framework 11 separates with electron beam, prevented the halation that causes owing to irregular reflection.
, according to the situation of broadcasting station application television display monitor central monitoring system, be in dark room, to be in low current condition sometimes.In the time of in this way, can see the halation of slight generation.Therefore, wish to suppress this halation.
Summary of the invention
The purpose of this invention is to provide a kind of cathode ray tube that can be applicable to overscanning, promptly be used under the situations such as dark room, this cathode ray tube also can prevent the generation of halation.
The invention provides following cathode ray tube.
(1) a kind of cathode ray tube that can make electron beam scanning in the outside of effective screen, described cathode ray tube has the beam shielding plate between the deflection center of the framework that is arranged at the color selecting pole system and electron beam, so that make electron beam scanning when effective screen outside, prevent electron beam bump framework, it is characterized in that, form beam shielding plate, make the path that is arranged essentially parallel to electron beam in the front end surface of the inboard barricade of screen, or extend back from electron beam path.
(2) cathode ray tube described in (1), its beam shielding plate have has bending to the fore-end of color selecting pole system side be arranged essentially parallel to the front end surface of electron beam path.
(3) cathode ray tube described in (1) makes the front end surface of beam shielding plate form the conical surface.
(4) cathode ray tube described in (1) forms its beam shielding plate, makes its fore-end bending to the color selecting pole system side, and makes its front end face form the conical surface.
The present invention is based on following discovery: because beam shielding plate has certain thickness, its front end surface is with the transmit direction of heeling condition towards electron beam, at this front end surface reflection electronic bundle brokenly, the electron bombard fluorescence screen side of reflection, because this fact just causes halation when overscanning.
That is to say, cathode ray tube of the present invention has the beam shielding plate of ingenious shaping, the front end surface of beam shielding plate is arranged essentially parallel to electron beam path, or extend back from electron beam path, thereby prevented the front end surface of electron beam impingement of electrons bundle barricade, with the reflection of electron beam, thereby can prevent halation in front end surface.
To the color selecting pole system side, make front end surface be arranged essentially parallel to electron beam path the bending of the fore-end of beam shielding plate, or to make the front end surface of beam shielding plate be the conical surface, can form the front end surface of the beam shielding plate of this mode.
Description of drawings
Describe above-mentioned and other purpose and feature of the present invention below with reference to accompanying drawings in detail, wherein:
Fig. 1 is the profile of the general structure of cathode ray tube;
Fig. 2 is the plane graph of the colour-selecting mechanism of cathode ray tube;
Fig. 3 is the view with the generation of conventional electrical bundle reflecting plate explanation halation;
Fig. 4 is the plane graph of colour-selecting mechanism in the cathode ray tube of the embodiment of the invention;
Fig. 5 is the view of the fore-end of reflecting electron beam plate one example of the present invention;
Fig. 6 is another routine view of reflecting electron beam plate of the present invention; With
Fig. 7 is the view of an example again of reflecting electron beam plate of the present invention.
Embodiment
Below, embodiments of the invention are described.Fig. 4 is the plane graph of colour-selecting mechanism in the cathode ray tube of the present invention.Cathode ray tube of the present invention is identical with conventional cathode ray tube shown in Figure 1, beam shielding plate 1 difference just, so be denoted by like references among Fig. 4 with Fig. 1 in identical structure member.
Among Fig. 4, framework 11 is attached in the color selecting pole system 10 that is called shadow mask or hole grid.Inner magnetic screen (IMS) 13 is attached on this framework by normal temperature compensating plate (STC plate) 14.Spring 15 is attached on the framework 11 by spring fixture 16, and spring 15 is used for colour-selecting mechanism is attached to phosphor screen shown in Figure 14.And, be provided with long and thin rectangular electron beam barricade 1 along the vertical direction of cathode ray tube, and it be clipped between inner magnetic screen 13 and the normal temperature compensating plate 14.The front of beam shielding plate 1 is protruding in the central shaft C of color selecting pole system 10 side, and prevents the framework 11 that electron beam E bump vertically is provided with.
Electron beam path E shown in Figure 4 arrives the distal-most end narrow slit ES (fluoroscopic end is promptly corresponding to the end in effective screen district) of color selecting pole system from deflection center DC.Usually, cathode ray tube is used for this with interior zone (being called underdevelopment), but in the television monitor of usefulness such as broadcasting station, makes this point of electron beam scanning part (being called overscanning) in addition.When the deflection angle of the normal full scan half-angle α that makes the inswept electron beam path E shown in Figure 4 of electron beam, electron beam hits is to being added with high-tension beam shielding plate 1, and this beam shielding plate 1 is fixed on the front surface side (deflection center side) of framework.This electron beam is reflected to the direction different with phosphor screen shown in Figure 14 or is absorbed.Thus, prevented electron beam bump framework 11 and because of due to the irregular reflection to fluoroscopic halation.
As shown in Figure 3, beam shielding plate 12 is arranged perpendicular to central shaft C.Under this state because plate has certain thickness, when the front end surface 12a of this plate when the electron beam transmit direction is orientated, electron beam strikes this front end surface 12a and is reflected to phosphor screen 4.This is the origin cause of formation of halation.
In the embodiment of the invention, the shape of this beam shielding plate 1 is done very ingeniously.Fig. 5 illustrates the enlarged drawing of its front.The fore-end of this beam shielding plate 1 is bent to the color selecting pole system side, makes its front end surface 1a be arranged essentially parallel to the path E of electron beam.Thus, electron beam no longer clashes into this front end surface 1a, and the electronics of impingement of electrons bundle barricade 1 is reflected and absorbs to the deflection center side or by beam shielding plate 1.Therefore, do not reflect electronics to phosphor screen 4.Thus, even under dark room, little current status, use cathode ray tube, can not cause halation yet.
When the path of electron beam E reaches the edge of beam shielding plate 1, the bending angle θ of beam shielding plate 1 shown in Figure 5 is preferably identical with angle of deflection basically, so that front end surface 1a is arranged essentially parallel to the path of electron beam, bending angle θ can change in about 5 ° scope certainly.If bending angle is worth less than this, front end surface 1a will be along the transmit direction orientation of electron beam, and electron beam will clash into front end surface 1a, make electron reflection to phosphor screen 4, cause halation.On the other hand, if bending angle is worth greater than this, then might make the electronics of the surperficial 1b reflection of bending reach phosphor screen 4.And the viewpoint from front end surface is located easily preferably makes bending part be positioned as close to the edge.
Cathode ray tube of the present invention with beam shielding plate of given shape shown in Figure 5, be used to experimentize with cathode ray tube, occur the margin of safety of halation under the more different over-scanning amount (amount of deflection) at phosphor screen 4 from effective platen edge of screen to non-effective screen with the beam shielding plate 12 before the improvement shown in Figure 3.
In the conventional cathode ray tube shown in Figure 2, cause halation (at the state of the front end surface generation reflex time of beam shielding plate) at about 3～4mm, but in the cathode ray tube of the embodiment of the invention, just cause halation (state during electron beam hits inner magnetic screen plate plate) at about 15mm.The display monitor central monitoring system that the broadcasting station is used uses 105～107% overscanning usually.For example in 20 inches the pipe, have in the overscanning of a side for about 10mm, therefore proof can guarantee enough allowances with the cathode ray tube of the embodiment of the invention.
In addition, beam shielding plate 1A shown in Figure 6 is and the similar flat board of conventional electrical bundle barricade, but by front end surface is made for the conical surface, front end surface is extended back from electron beam path, and make electron beam can not clash into this surface.Consider the orientation of reflecting electron beam plate etc., can suitably select the angle of this conical surface.Method as for front end surface being formed the conical surface just can form with known etching method.
In addition, among the reflecting electron beam plate 1B shown in Figure 7, owing to bent leading section, and at the front end surface formation conical surface, even bending angle departs from α shown in Figure 5 slightly or beam shielding plate produces rigging error, because the conical surface of front end surface has increased nargin, thereby can prevent the electron beam hits front end surface reliably.
In the cathode ray tube of the present invention, form beam shielding plate dexterously, thereby the generation of halation can prevent overscanning reliably the time.
Claims (4)
1. a cathode ray tube is characterized in that making the effectively outside of screen of electron beam scanning, and this pipe comprises:
Be arranged at the beam shielding plate between the deflection center of the framework of color selecting pole system and electron beam, prevent when electron beam scanning during in effective screen outside electron beam clash into described framework,
Described beam shielding plate is arranged essentially parallel to the path (E) of electron beam that arrives the distal-most end narrow slit (ES) of color selecting pole system from deflection center (DC) towards the front end surface (1a) of central shaft (C), perhaps described front end surface on described electron beam transmit direction gradually away from the path of described electron beam.
2. cathode ray tube as claimed in claim 1, it is characterized in that, described beam shielding plate has a fore-end, and described front end surface is positioned on the described fore-end, and this fore-end bends to the color selecting pole system side so that described front end surface is arranged essentially parallel to described electron beam path.
3. cathode ray tube as claimed in claim 1 is characterized in that the front end surface of described beam shielding plate forms the conical surface.
4. cathode ray tube as claimed in claim 1, the fore-end bending that it is characterized in that described beam shielding plate is to the color selecting pole system side and form the conical surface.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2125396A JPH09219162A (en) | 1996-02-07 | 1996-02-07 | Cathode-ray tube |
| JP021253/96 | 1996-02-07 | ||
| JP021253/1996 | 1996-02-07 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1161561A CN1161561A (en) | 1997-10-08 |
| CN1125479C true CN1125479C (en) | 2003-10-22 |
Family
ID=12049928
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 97101893 Expired - Fee Related CN1125479C (en) | 1996-02-07 | 1997-02-07 | Cathode ray tube with beam shielding plate for preventing halation |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPH09219162A (en) |
| CN (1) | CN1125479C (en) |
| GB (1) | GB2310079B (en) |
| SG (1) | SG89246A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100287841B1 (en) * | 1998-07-20 | 2001-06-01 | 구자홍 | Structure for preventing halation of flat type braun tube |
| US6979943B2 (en) | 2001-03-19 | 2005-12-27 | Matsushita Electric Industrial Co., Ltd. | Cathode ray tube having magnetic shield with a bent portion |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4002941A (en) * | 1966-10-27 | 1977-01-11 | Rca Corporation | Shadow mask cathode ray tube shield |
| NL6900696A (en) * | 1969-01-16 | 1970-07-20 | ||
| GB1257516A (en) * | 1969-11-20 | 1971-12-22 | ||
| JPS63231843A (en) * | 1987-03-20 | 1988-09-27 | Hitachi Ltd | Shadow mask type color picture tube |
| EP0439884A1 (en) * | 1990-01-31 | 1991-08-07 | Samsung Display Devices Co., Ltd. | Shadow mask frame for prevention of halation |
-
1996
- 1996-02-07 JP JP2125396A patent/JPH09219162A/en active Pending
-
1997
- 1997-01-30 SG SG9700219A patent/SG89246A1/en unknown
- 1997-02-03 GB GB9702134A patent/GB2310079B/en not_active Expired - Fee Related
- 1997-02-07 CN CN 97101893 patent/CN1125479C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH09219162A (en) | 1997-08-19 |
| GB2310079B (en) | 2000-10-04 |
| CN1161561A (en) | 1997-10-08 |
| GB9702134D0 (en) | 1997-03-26 |
| GB2310079A (en) | 1997-08-13 |
| SG89246A1 (en) | 2002-06-18 |
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| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |