EP0446878A2 - Bildanzeigevorrichtung - Google Patents

Bildanzeigevorrichtung Download PDF

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Publication number
EP0446878A2
EP0446878A2 EP91103789A EP91103789A EP0446878A2 EP 0446878 A2 EP0446878 A2 EP 0446878A2 EP 91103789 A EP91103789 A EP 91103789A EP 91103789 A EP91103789 A EP 91103789A EP 0446878 A2 EP0446878 A2 EP 0446878A2
Authority
EP
European Patent Office
Prior art keywords
metal back
layer
image display
display element
electron beams
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.)
Granted
Application number
EP91103789A
Other languages
English (en)
French (fr)
Other versions
EP0446878A3 (en
EP0446878B1 (de
Inventor
Keiichi Otake
Noboru Aikawa
Atsunori Hosoki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from JP6315890A external-priority patent/JPH03266339A/ja
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Publication of EP0446878A2 publication Critical patent/EP0446878A2/de
Publication of EP0446878A3 publication Critical patent/EP0446878A3/en
Application granted granted Critical
Publication of EP0446878B1 publication Critical patent/EP0446878B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • H01J29/10—Screens on or from which an image or pattern is formed, picked up, converted or stored
    • H01J29/18—Luminescent screens
    • H01J29/28—Luminescent screens with protective, conductive or reflective layers

Definitions

  • the present invention generally relates to a cathode-ray tube for displaying the images by the application, upon the phosphor, of the electrons generated by the cathode within a vacuum cell, and more particularly, to an image display element using a cathode-ray tube which has a potential gradient within the vacuum cell.
  • the Braun tube is mainly used as a display element for a color television image display use, it is impossible to make the conventional Braun tube thinner, because the depth thereof is much longer as compared with the size of the picture face.
  • This is a plate type image display apparatus which may fetch the electron beams from a plurality of linear thermal cathodes, may make the electron beams, controlled by an electron beam control electrode, collide against the fluorescent screen, and may display letters, images and so on.
  • the plate type image display apparatus is constructed as shown in Fig. 1.
  • a back electrode 51 is adapted to direct into the front face direction the electron beams 72 to be emitted from a plurality of linear thermal cathodes shown in reference numerals 52a through reference numerals 52d.
  • An electron beam fetching electrode 53 fetches the electrons by the linear thermal cathode 52a through 52d.
  • Through holes 62 are provided in the electrode 53 to let the electron beams 72 pass through them.
  • a signal electrode 54 which is provided to apply the video signals is composed of a plurality of control electrodes 64.
  • the control electrode 64 has through holes 63 therein to let the electron beams 72 pass through it.
  • a first focusing electrode 55 and a second focusing electrode 56 are provided to focus the electron beams 72 in the horizontal and vertical directions.
  • a horizontal deflection electrode 68 deflects the electron beams in the right, left directions of the picture face, and is composed of one set of comb type of electrode 57a and 57b.
  • the electrodes of the comb type of electrodes 57a and 57b constitute a slot 67 to let the electron beams 72 pass through with the mutual electrodes.
  • a vertical deflection electrode 71 is provided to deflect the electron beams 72 in the vertical direction of the picture face, and is composed of a set of comb type of electrodes 58a and 58b.
  • the comb type of electrodes 58a and 58b constitute a slot 70 with the mutual electrodes to let the electrode beams 72 to pass through it.
  • a face plate (surface glass cell) 60 has a screen 73 composed of a three color phosphor layer of red, green, blue, a black stripe layer provided among them, and a metal back layer provided behind them on the inner face thereof.
  • a metallic plate 61 made of a back cell, and the face plate 60 constitute a vacuum cell.
  • Fig. 2 A, B are views showing the internal construction of the Braun tube and the present image display element of the conventional embodiment.
  • the portions which are not necessary for illustration are omitted.
  • the electron beams 82 transmitted from the electron gun 81 are applied upon the metal back 84 positioned on the face 83. Approximately 80 % of the electron beams pass through the metal back 84 and becomes incident to the fluorescent screen applied upon the face 83 so as to emit the light.
  • the electron beams 82 of approximately remaining 20 % are reflected on the metal back 84 and become the rearward dispersed electrons 85 so that they are absorbed by a funnel 86 and a shadow mask. This is because the interior of the funnel 86 is equipotential.
  • the approximately 20 % of the electron beams 82 transmitted from the cathode within the electrode 88 becomes the rearward dispersed electrons 85 as in the Braun tube in the case of the present image display element B of the conventional embodiment, the high voltage of approximately 10KV is applied upon the above described metal back 84 with the electrode 88 being provided with respect to approximately 300V.
  • the element has an electrode gradient therein.
  • the rearward dispersed electrons 85 are applied again upon the metal back 84 on the face 83, and the fluorescent screen except for the place where the electron beams 82 become incident primarily emits the light, thus reducing the contrast ratio considerably.
  • the metal back 84 is composed of aluminum layer.
  • the present invention has been developed with a view to substantially eliminating the above discussed drawbacks inherent in the prior art, and has for its essential object to provide an improved image display element.
  • Another important object of the present invention is to provide an improved image display element which is adapted to prevent the reduction in the contrast ratio by the rearward dispersed electrode so as to display the distinct images of good contrast.
  • the carbon layer are formed on the metal back layer on the face plate.
  • the thickness of the metal back layer is adjusted, and the transmission ratio of the transmission factor of the rearward dispersed electrons to be generated at the rush time of the electronic beams is to be restrained at 30% or lower.
  • an image display element where the generation of the rearward dispersed electrons is reduced by approximately half, the light emission of the fluorescent screen except for the location where the electron beams become primarily incident is also reduced by half, the contrast ratio is improved twice.
  • Fig. 3 is an approximately side sectional view of an image display element of the present invention.
  • Fig. 4 is a structural model showing a forming method of a carbon layer.
  • Fig. 5 is a graph showing the relationship of the generation factor (rearward dispersion coefficient) ⁇ of the rearward dispersed electrons with respect to the atomic number Z of an target to which the electron beams become incident.
  • reference numeral 1 is a back electrode equivalent to the back electrode 51 of Fig. 1
  • reference numeral 2 is a linear cathode equivalent to a linear cathode 52 of Fig.
  • reference numerals 3 through 7 are electrode blocks equivalent to a beam fetching electrode 53, a signal electrode 54, a focusing electrode 55, horizontal ⁇ vertical deflecting electrodes 57, 58 of Fig. 1
  • reference numeral 8 is a screen plate equivalent to a screen 73 of Fig. 1, the screen plate being composed of a glass plate 21, a phosphor 20 to be positioned on it, a metal back (aluminum layer) 101 provided on the phosphor 20, a carbon layer 104 provided on the metal back 101.
  • Reference numeral 102 shows electron beams to be generated from the linear cathode 2
  • reference numeral 103 is a rearward dispersed electrons (secondary electrons).
  • the rearward dispersed electrons 103 are 18% of the electron beams 102 to be incident in a case of aluminum (atomic number 13) to be normally used even in the metal back 101.
  • the rearward dispersed electrons 103 become 9% of the electron beams 102 to become incident in the case of the carbon (atomic number 6). If the carbon layer 104 is formed on the metal back 101, the generation of the rearward dispersion electrons 103 may be prevented by half, and the contrast ratio may be improved twice.
  • Fig. 4 is a structural model of the carbon layer forming method.
  • the phosphor 20 and the metal back 101 are already formed on the internal face of the glass plate 21.
  • Carbon liquid 11 with powdered carbon being dissolved in a solvent such as water, alcohol or the like is put into a sprayer 12, is sprayed onto the metal back 101 of the glass plate 21 so as to the carbon layer 104. Thereafter, it is burned at approximately 450°C and the face plate is completed as a whole.
  • the thickness of the carbon layer 104 is adjusted by the spraying time or the spraying amount of the sprayer 12.
  • the carbon layer 104 is too thick, the passing ratio of the electron beams is lowered, thus reducing the brilliance. Therefore, the carbon layer of approximately 0.3 through 0.4 in the thermal absorption factor is formed this time.
  • Fig. 6 is a structural model of the carbon layer forming method in a second embodiment of the image display element of the present invention.
  • the carbon layer is formed by the electric evaporation, the more uniform carbon layer may be obtained than by the spraying in the first embodiment.
  • the high-tension voltage to be applied upon the metal back on the face is comparatively low (in a case 15KV or lower), the face where uneven brilliance is not caused may be formed.
  • Silicon resin is provided in the thickness of 2 microns on the full face of the resin film of approximately several tens of microns as a mold releasing layer.
  • the carbon film is formed with spraying, electric evaporating or the like on the mold releasing layer so as to obtain the carbon layer forming sheet.
  • the carbon layer forming sheet is transferred under pressure adherence on the metal back layer on the face plate, is burned at approximately 450°C to complete the face plate as a whole.
  • the carbon layer forming sheet may be kept prepared in advance.
  • the pressure adherence transferring operation has only to be effected at the face plate completing step.
  • the simplification of the step may be effected.
  • the equal effect may be obtained if the normal temperature solid material which is smaller at the atomic number than aluminum is used.
  • Fig. 7 is a graph showing the relation of the electron incident energy to the energy transmission factor when the thickness of the metal back 101 is provided as parameters.
  • the metal back 101 is 1000 ⁇ in thickness with the electric potential of 10KV being applied upon it in Fig. 3.
  • the electron beams 102 generated from the linear cathode 2 (potential OV) are accelerated by the potential gradient with respect to the metal back 101, and are applied upon the metal back with the incident energy of 10keV.
  • the target is aluminum
  • the incident 18% is dispersed rearwards as rearward dispersed electrons 103, and the energies of the rearward dispersed electrons 103 become approximately 6keV (approximately 60 % of the incident energies).
  • the secondary electrons dispersed rearwards rushes into the metal back again by the energies of approximately 6keV by the above described potential gradient.
  • the thickness of the metal back 101 is 1000 ⁇ , the energy transmission factor of the incident electrons (10keV) is 92%, the energy transmission factor of the rearward dispersion electrons (6keV) is 64%. Therefore, it is undesirable that the brilliance is extremely high, the transmission factor of the rearward dispersed electrons is also high, and the contrast is deteriorated.
  • the thickness of the metal back is made 2000 ⁇ , the energy transmission factors of the incident electrons, the rearward dispersed electrons are respectively 77%, 16%.
  • the thickness of the metal back 101 is made 1000 ⁇ ⁇ 2000 ⁇ , the energy transmission factor (which is proportional to brilliance) of the incident electrons becomes 92% - 77% and the brilliance is also lowered somewhat.
  • the energy transmission factor (proportional to halation) of the rearward dispersed electrons is reduced as extremely low as 64% ⁇ 16%. Therefore, the brilliance is satisfactory and the contrast is also extremely good. But when the thickness of the metal back increases extremely, the brilliance is lowered large, so that the proper thickness is demanded.
  • the balancing is provided in the brilliance and the contrast if the energy transmission factor of the rearward dispersed electrons is 30% or lower.
  • the thickness is proper to be 2000 ⁇ or more and 3500 ⁇ or lower when the voltage of the metal back is 10KV. In the case of 9kV, it is proper to be 1500 ⁇ or more and 3000A or lower. In the case of 8KV, it is proper to be 1500 ⁇ or more and 2000 ⁇ or lower.
  • the halation may be considerably reduced within some brilliance reduction by the adjustment of the thickness.

Landscapes

  • Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
EP19910103789 1990-03-14 1991-03-13 Bildanzeigevorrichtung Expired - Lifetime EP0446878B1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP63158/90 1990-03-14
JP6315890A JPH03266339A (ja) 1990-03-14 1990-03-14 画像表示素子
JP79442/90 1990-03-28
JP7944290 1990-03-28

Publications (3)

Publication Number Publication Date
EP0446878A2 true EP0446878A2 (de) 1991-09-18
EP0446878A3 EP0446878A3 (en) 1992-03-25
EP0446878B1 EP0446878B1 (de) 1998-06-03

Family

ID=26404244

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19910103789 Expired - Lifetime EP0446878B1 (de) 1990-03-14 1991-03-13 Bildanzeigevorrichtung

Country Status (2)

Country Link
EP (1) EP0446878B1 (de)
DE (1) DE69129506T2 (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0610872A2 (de) * 1993-02-08 1994-08-17 Matsushita Electric Industrial Co., Ltd. Elektronenstrahl-Bildwiedergabevorrichtung und Erzeugung derselben
EP1134073A1 (de) * 2000-03-14 2001-09-19 Dai Nippon Printing Co., Ltd. Gassperrfilm

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1281588B (de) * 1963-07-31 1968-10-31 Sony Corp Kathodenstrahlroehre
DE2164174A1 (de) * 1970-12-28 1972-07-06 Rca Corp Verfahren zum Anbringen einer Kohlenstoffschicht auf einer die Leuchtstoffschicht auf dem Frontplattenteil einer Kathodenstrahlröhre bedeckenden lichtreflektierenden Metallschicht
GB2120840A (en) * 1982-05-12 1983-12-07 Philips Electronic Associated Contrast improvement in vacuum image display devices

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1281588B (de) * 1963-07-31 1968-10-31 Sony Corp Kathodenstrahlroehre
DE2164174A1 (de) * 1970-12-28 1972-07-06 Rca Corp Verfahren zum Anbringen einer Kohlenstoffschicht auf einer die Leuchtstoffschicht auf dem Frontplattenteil einer Kathodenstrahlröhre bedeckenden lichtreflektierenden Metallschicht
GB2120840A (en) * 1982-05-12 1983-12-07 Philips Electronic Associated Contrast improvement in vacuum image display devices

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0610872A2 (de) * 1993-02-08 1994-08-17 Matsushita Electric Industrial Co., Ltd. Elektronenstrahl-Bildwiedergabevorrichtung und Erzeugung derselben
EP0610872A3 (de) * 1993-02-08 1994-10-12 Matsushita Electric Ind Co Ltd Elektronenstrahl-Bildwiedergabevorrichtung und Erzeugung derselben.
US5451835A (en) * 1993-02-08 1995-09-19 Matsushita Electric Industrial Co., Ltd. Electron beam display device and production thereof
EP1134073A1 (de) * 2000-03-14 2001-09-19 Dai Nippon Printing Co., Ltd. Gassperrfilm
EP1522403A2 (de) * 2000-03-14 2005-04-13 Dai Nippon Printing Co., Ltd. Gassperrfilm
EP1522403A3 (de) * 2000-03-14 2008-10-22 Dai Nippon Printing Co., Ltd. Gassperrfilm

Also Published As

Publication number Publication date
EP0446878A3 (en) 1992-03-25
EP0446878B1 (de) 1998-06-03
DE69129506T2 (de) 1998-10-01
DE69129506D1 (de) 1998-07-09

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