EP0464938B1 - Thin-type picture display device - Google Patents

Thin-type picture display device Download PDF

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Publication number
EP0464938B1
EP0464938B1 EP91201668A EP91201668A EP0464938B1 EP 0464938 B1 EP0464938 B1 EP 0464938B1 EP 91201668 A EP91201668 A EP 91201668A EP 91201668 A EP91201668 A EP 91201668A EP 0464938 B1 EP0464938 B1 EP 0464938B1
Authority
EP
European Patent Office
Prior art keywords
apertures
selection
plate
electron source
electron
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
Application number
EP91201668A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0464938A1 (en
Inventor
Gerardus Gegorius Petrus Van Gorkom
Petrus Hubertus Franciscus Trompenaars
Siebe Tjerk De Zwart
Nicolaas Lambert
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.)
Koninklijke Philips NV
Original Assignee
Koninklijke Philips Electronics NV
Philips Electronics NV
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
Application filed by Koninklijke Philips Electronics NV, Philips Electronics NV filed Critical Koninklijke Philips Electronics NV
Publication of EP0464938A1 publication Critical patent/EP0464938A1/en
Application granted granted Critical
Publication of EP0464938B1 publication Critical patent/EP0464938B1/en
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
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/10—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes
    • H01J31/12—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes with luminescent screen
    • H01J31/123—Flat display tubes
    • H01J31/125—Flat display tubes provided with control means permitting the electron beam to reach selected parts of the screen, e.g. digital selection
    • H01J31/126—Flat display tubes provided with control means permitting the electron beam to reach selected parts of the screen, e.g. digital selection using line sources
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/10—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes
    • H01J31/12—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes with luminescent screen
    • 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
    • H01J29/028—Mounting or supporting arrangements for flat panel cathode ray tubes, e.g. spacers particularly relating to electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2329/00—Electron emission display panels, e.g. field emission display panels
    • H01J2329/86—Vessels
    • H01J2329/8625—Spacing members
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2329/00—Electron emission display panels, e.g. field emission display panels
    • H01J2329/86—Vessels
    • H01J2329/8625—Spacing members
    • H01J2329/863—Spacing members characterised by the form or structure

Definitions

  • the invention relates to a picture display device having a vacuum envelope for displaying pictures composed of pixels on a luminescent screen, and particularly relates to a thin picture display device (i.e. a picture display device having a small "front-to-back dimension").
  • Typical state-of-the-art approximations to thin-type picture display devices are devices having a transparent face plate and a rear plate which are interconnected by means of partitions and in which the inner side of the face plate is provided with a phosphor pattern, one side of which is provided with an electrically conducting coating (the combination also being referred to as luminescent screen). If (video information-controlled) electrons impinge upon the luminescent screen, a visual image is formed which is visible via the front side of the face plate.
  • the face plate may be flat or, if desired, curved (for example, spherical or cylindrical).
  • a specific category of picture display devices of the thin type uses single or multiple electron beams which initially extend substantially parallel to the plane of the display screen and are ultimately bent towards the display screen so as to address the desired areas of the luminescent screen either directly or by means of, for example, a selection grid structure.
  • the expression electron beam is understood to mean that the paths of the electrons in the beam are substantially parallel, or extend only at a small angle to one another and that there is a main direction in which the electrons move).
  • the above-mentioned devices operating with controlled electron beams require, inter alia , complicated electron-optical constructions.
  • picture display devices of the single beam type generally require a complicated (channel plate) electron multiplier of the matrix type, certainly if they have slightly larger screen formats.
  • a picture display device having a vacuum envelope with a transparent front wall whose inner surface is provided with a luminescent screen for displaying pictures composed of pixels and a rear wall opposite to the front wall,comprises an arrangement of juxtaposed sources for producing electrons, local transport ducts cooperating with the sources and having respective walls of electrically substantially insulating material having a secondary emission coefficient suitable for transporting, through the ducts, produced electrons in the form of electron currents, and selection electrode means for effecting extraction of electrons from the transport ducts at selected extraction locations for transport towards the luminescent screen, a selection plate system arranged in spaced relationship between the front and rear walls by means of front and rear spacers, said selection plate system having a main surface with an arrangement of apertures defining the extraction locations and, aligned therewith, a row of aperture defining electron source locations.
  • the inventive approach of providing a thin-type picture display device is based on the discovery that electron transport is possible when electrons impinge on an inner wall of an elongate evacuated cavity (so-called compartment) defined by walls of electrically substantially insulating material (for example, glass or synthetic material) if an electric field of sufficient power is realised in the longitudinal direction of the compartment (for example, by applying an electric potential difference across the ends of the compartment).
  • the impinging electrons then generate secondary electrons by wall interaction which are attracted to a further wall section and in their turn generate secondary electrons by wall interaction.
  • the circumstances field strength E, electrical resistance of the walls, secondary emission coefficient ⁇ of the walls
  • a flat picture display device can be realised by providing each one of a plurality of juxtaposed compartments constituting transport ducts with a column of apertures constituting extraction locations at one side to be directed towards a display screen. In this case it is practical to arrange the extraction locations of adjacent transport ducts along parallel rows extending transversely to the transport ducts.
  • an addressing means is provided with which electrons extracted from the compartments can be directed towards the screen for producing a picture composed of pixels.
  • the device according to the invention specifically has a selection plate positioned between the front and rear walls and having an aperture pattern defining both the extraction locations and the locations of the electron sources.
  • Such a structure can be easily made with a sufficiently great accuracy by means of, for example, lithographic techniques.
  • Electrically conducting strips having apertures aligned with the apertures in the plate and constituting electrode means for selectively withdrawing electrons from the aperture can be easily provided on the structure by means of, for example photolithographic techniques. Since in the construction described above the locations of the electrons impinging upon the luminescent screen (the "spots") are defined by the apertures in the selection plate, the other components which are used, such as the spacers, may be made with less precise accuracy, which has a cost-saving effect. Nevertheless a very high resolution can be achieved because the selection plate itself can be made with very great accuracy.
  • the selection plate system has supporting means at its side facing the luminescent screen, which means support the arrangement of electron sources for cooperation with the transport ducts.
  • trip-shaped electron source drive electrodes each having an aperture which is aligned with one of the apertures defining the electron source locations are preferably arranged on a main surface of the selection plate system.
  • an embodiment is characterized in that the electron source arrangement is present proximate to an edge of the main surface and in that each aperture defining an electron source location is associated with a respective strip-shaped electron source drive electrode arranged on the main surface, which drive electrode extend from said aperture towards said edge.
  • Drive circuits (possibly in chip form - "chip on glass”) may be arranged between the ends of the drive electrodes and the edge. These circuits may be present within or outside the vacuum envelope.
  • the apertures defining the extraction locations are arranged along parallel rows extending transversely to the transport ducts.
  • the front (screen-sided) spacer preferably comprises a system of mutually parallel walls which extend between the apertures at an angle to the rows of apertures.
  • an embodiment which is characterized in that per extraction location there are a first and a second aperture and in that the selection electrode means comprise a first system of sub-electrodes for line-sequentially driving the first apertures and a second system of sub-electrodes for line-sequentially driving the second apertures.
  • Colour display is possible in different manners with the device according to the invention.
  • a constructive simple embodiment is characterized in that the number of parallel rows is three time as large for colour display as the number of lines of a picture to be displayed and corresponds to the number of phosphor lines on the luminescent screen.
  • n picture lines When there are n picture lines, 3n electric connections and drive circuits are required in the most general case.
  • the preselection plate disposed closer to the rear wall and having apertures defining the extraction locations and the electron source locations; and one fine selection plate facing the front wall and having at least two apertures associated with each extraction location in the preselection plate.
  • n m rows of preselection apertures in the preselection plate and 3m fine selection apertures for each preselection aperture only n m +3m connections/drive circuits are sufficient in the case of colour display of n picture lines on the screen. Consequently, if m is chosen to be 3, 201 instead of 1728 connections/drive circuits are required for displaying 576 picture lines.
  • Fig. 1 shows a thin-type picture display device 1 according to the invention having a front wall (window) 3 and a rear wall 4 located opposite said front wall.
  • a corresponding number of separate electron emitters may alternatively be used.
  • Each of these emitters is to provide a relatively small current so that many types of cathodes (cold or thermal cathodes) are suitable as emitters.
  • the emission is preferably controlled by means of the video signal.
  • An alternative is to apply the video information to a gating structure arranged subsequent to the electron source arrangement, (for example, a line cathode in this case) instead of to the emitters.
  • the electron source arrangement 5 is arranged opposite to entrance apertures of a row of transport ducts 11, 11′, 11 ⁇ extending substantially parallel to the screen, which ducts are defined by compartments 6, 6′, 6 ⁇ , ... etc. in this case one compartment for each electron source.
  • One of these compartments is shown in a cross-section in Fig. 3.
  • At least one wall (preferably the rear wall) of each compartment is made of a material which has a suitable electrical resistance for the purpose of the invention (for example, ceramic material, glass, synthetic material - coated or uncoated) and which has a secondary emission coefficient ⁇ > 1 over a given range of primary electron energies (see Fig. 4).
  • the electrical resistance of the wall material has such a value that a minimal amount of current will flow in the walls in the case of a field strength (E y ) in the compartments of the order of one hundred to several hundred Volts per cm, required for the electron transport. Currents as low as 1 micro-ampere have been found to be realisable.
  • the invention is based on the recognition that vacuum electron transport within compartments having walls of electrically insulating material is possible if an electric field (E y ) of sufficient power is applied in the longitudinal direction of the compartment.
  • E y electric field
  • Such a field realises a given energy distribution and spatial distribution of electrons injected into the compartment so that the effective secondary emission coefficient ⁇ eff of the walls of the compartment will be equal to 1 on average in operation. Under these circumstances one electron will leave for each electron which enters (on average), in other words, the electron current is constant throughout the compartment and is approximately equal to the current which enters.
  • Another advantage is that in the state ⁇ eff ⁇ 1 the electron current in the compartment is constant and can be made to be very satisfactorily equal via measuring and feed-back or via current control for each compartment so that a uniform picture can be realised on the luminescent screen.
  • the compartment walls facing the luminescent screen 7, which is arranged on the inner wall of the panel 3, are constituted by a selection plate 10 (see Fig. 2).
  • This plate 10 has extraction apertures 8, 8′, 8 ⁇ , .... etc. which define extraction locations.
  • a "gating" structure can be used to "withdraw” a flow of electrons from a desired aperture when using cathodes which are not separately driven.
  • cathodes which are individually driven by means of electrodes G1, G2, ... are preferably used in combination with apertured selection electrodes 9, 9′, 9 ⁇ , .... (see also Fig. 5) to be energized by a selection voltage.
  • Fig. 5 apertured selection electrodes 9, 9′, 9 ⁇ , ....
  • an apertured plate 10 may be electroless nickel-plated, whereafter a strip pattern is formed from the electroless nickel-plated layer by means of etching.
  • selection electrodes 9, 9′, 9 ⁇ .... which may alternatively be provided on only one of the main surfaces of plate 10, are implemented for each picture line, for example in the way shown in Fig. 5 ("horizontal" electrodes 9, 9′, 9 ⁇ , ...
  • Desired locations on the screen 7 can be addressed by means of (matrix) drive of the individual cathodes and the selection electrodes 9, 9′, 9 ⁇ , Vietnamese For example, voltages which increase substantially linearly (as viewed from the cathode side) are applied to the selection electrodes 9, 9′, 9 ⁇ , .... When a picture line must be activated, i.e.
  • a pulsatory voltage ⁇ U is added to the local voltage.
  • ⁇ U may be comparatively low (of the order of, for example 100 V to 200 V).
  • V a is taken across the total compartment height, which is just too small to draw electrons from apertures. This does happen by applying a positive line selection pulse of the correct value.
  • Selection plate 10 is spaced apart from the front wall 3 and the rear wall 4.
  • the side walls of the compartments 6, 6′, 6 ⁇ , ... are used as rear spacers to keep the plate 10 spaced apart from the rear wall 4 and "vertical" walls 12 extending transversely to the front wall 3 are provided which are used as front spacers for spacing the plate 10 apart from the front wall 3.
  • the walls 12 need not be absolutely “vertical”, i.e. transverse to the rows of selection electrodes 9, 9′, 9 ⁇ , .... but they may alternatively extend parallel to the row selection electrodes 9, 9′, 9 ⁇ , ....
  • the ("vertical") walls 12 are preferably made of a material having a 2nd cross-over point E II of the secondary emission coefficient ⁇ which is so low that there is no unwanted field emission (see Fig. 4). For example, macor and window glass have been found suitable.
  • Figs. 2 and 5 show a plurality of further constructive details which may be present in the display device of Fig. 1: A contact track 13 provided on the front wall 3 for electrically contacting of the luminescent screen.
  • Electrodes 15, 16 arranged on the rear wall 4 and on the bottom of the electron transport compartments 6, 6′, 6 ⁇ , .... for helping the electron transport; Measuring strips 17a, 17b arranged in the plate 10 opposite apertures 18a, 18b ... provided with extraction electrodes for checking the uniformity of the electron currents produced in the transport ducts 11, 11′, 11 ⁇ , ...;
  • a lead-in electrode 20 (approximately 1 mm high);
  • An electron source arrangement 5 This may be, for example, a line cathode whose extremities are suspended on the partitions or which is supported by supporting means (not visible in the Figure) arranged on the plate 10. Instead of a line cathode, separate electron emitters, for example p-n emitters secured on the plate 10 may be used.
  • the reference numeral 25 denotes a shielding means for the electron source arrangement.
  • the electron source arrangement 5 is arranged opposite a row of apertures 26, 26′, 26 ⁇ , .... which are aligned with the arrangement of extraction apertures 8, 8′, 8 ⁇ , ....
  • Fig. 6A is an elevational view of a cross-section through a holder supporting the device of Fig. 1, and Fig. 6B which is an elevational view of a longitudinal section through the holder 30.
  • External connectors are denoted by the reference numerals 31, 32 and 33.
  • the selection electrodes 9, 9′, 9 ⁇ , .... are implemented in such a way that the selection electrodes having an odd ordinal number extend as far as the left edge of selection plate 10 and the selection electrodes having an even ordinal number extend as far as the right edge of selection plate 10 (see Fig. 5). This simplifies the connection with the connectors 32, 33.
  • the emitter drive electrodes G1, G2 ... extend as far as the lower edge of the plate 10 and are connected to connector 31.
  • Fig. 7 shows diagrammatically a part of a selection plate 10 constituting the front wall of transport ducts 11, 11′, 11 ⁇ , .... with a pitch P.
  • the horizontal picture resolution is determined by the pitch of the transport ducts. A better resolution can thus be obtained by making this pitch smaller.
  • this has the drawback that the voltage drop across the ducts required for transporting the electron currents will increase, which is not always desirable.
  • This problem can be solved by leaving the pitch of the transport ducts unchanged and by giving the spacer structure the required smaller pitch, combined with an adapted pattern of the selection apertures and electrodes, as will be illustrated with reference to Fig. 7.
  • Fig. 7 shows two extraction apertures for each extraction location so that the pitch of the spacer walls is half (p/2) that of the transport ducts (p).
  • Each selection electrode 29 is divided into two apertured sub-electrodes 30a and 30b in the manner shown, which simplifies contacting. In this way the horizontal resolution can be doubled with respect to the construction shown in Fig. 1, while the transport ducts 11, 11′, 11 ⁇ .... can be controlled by the same voltages and in the same manner.
  • a well-defined electric voltage increasing from the cathode side is to be applied particularly across the front and rear walls of the transport ducts, the voltage on the front wall always being slightly lower at the same height.
  • This can be realised, for example, by adjusting the wall potential by means of a high-ohmic resistance layer provided on the relevant wall, such as the resistance layer 24 (Fig. 2) provided on the rear wall, and the electric contacts (22 and 23 in Fig. 2) contacting the resistance layer are used for connection to a voltage source.
  • This resistance layer may have a meandering or zigzag pattern for increasing the resistance.
  • the front wall potential may be adjusted by arranging strip-shaped electrodes on the inner side of the front walls of the transport ducts and giving them, in operation, a (substantially linearly) increasing potential. These electrodes may also be used advantageously for (picture) line selection by providing them with apertures aligned with the apertures in the preselection plate and connecting them to a circuit for providing a (positive) selection voltage.
  • Fig. 8 shows diagrammatically a selection plate system having a preselection plate 10a with preselection apertures 41 and a screen-sided fine selection plate 10b arranged at a distance therefrom.
  • three apertures 42, 42′, 42 ⁇ in the fine selection plate 10b are associated with each aperture 41, which apertures are drivable by means of fine selection electrodes 43, 43′, 43 ⁇ , respectively.
  • This provides the possibility of arranging the fine selection electrodes of corresponding apertures electrically parallel, for example, by means of coupling capacitors. If the preselection plate 10a has, for example, 200 rows of apertures, no more than 203 electric connections are required for displaying 600 picture lines on the screen in the case of monochrome display.
  • Plate 10a may be implemented like plate 10 in Fig. 7.

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  • Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
EP91201668A 1990-07-05 1991-06-28 Thin-type picture display device Expired - Lifetime EP0464938B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL9001529A NL9001529A (nl) 1990-07-05 1990-07-05 Beeldweergeefinrichting van het dunne type.
NL9001529 1990-07-05

Publications (2)

Publication Number Publication Date
EP0464938A1 EP0464938A1 (en) 1992-01-08
EP0464938B1 true EP0464938B1 (en) 1995-04-19

Family

ID=19857364

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91201668A Expired - Lifetime EP0464938B1 (en) 1990-07-05 1991-06-28 Thin-type picture display device

Country Status (6)

Country Link
EP (1) EP0464938B1 (zh)
JP (1) JPH0668815A (zh)
KR (1) KR920003232A (zh)
CN (1) CN1058297A (zh)
DE (1) DE69108997T2 (zh)
NL (1) NL9001529A (zh)

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5675212A (en) * 1992-04-10 1997-10-07 Candescent Technologies Corporation Spacer structures for use in flat panel displays and methods for forming same
US5614781A (en) * 1992-04-10 1997-03-25 Candescent Technologies Corporation Structure and operation of high voltage supports
US5424605A (en) * 1992-04-10 1995-06-13 Silicon Video Corporation Self supporting flat video display
US5742117A (en) * 1992-04-10 1998-04-21 Candescent Technologies Corporation Metallized high voltage spacers
US5532548A (en) * 1992-04-10 1996-07-02 Silicon Video Corporation Field forming electrodes on high voltage spacers
US5477105A (en) * 1992-04-10 1995-12-19 Silicon Video Corporation Structure of light-emitting device with raised black matrix for use in optical devices such as flat-panel cathode-ray tubes
US5578899A (en) * 1994-11-21 1996-11-26 Silicon Video Corporation Field emission device with internal structure for aligning phosphor pixels with corresponding field emitters
US5650690A (en) * 1994-11-21 1997-07-22 Candescent Technologies, Inc. Backplate of field emission device with self aligned focus structure and spacer wall locators
US5543683A (en) * 1994-11-21 1996-08-06 Silicon Video Corporation Faceplate for field emission display including wall gripper structures
JP3472391B2 (ja) * 1995-07-19 2003-12-02 東芝機械株式会社 ２軸押出機及びその２軸押出機を利用した押出方法
US6278066B1 (en) 1996-12-20 2001-08-21 Candescent Technologies Corporation Self-standing spacer wall structures
US5964630A (en) * 1996-12-23 1999-10-12 Candescent Technologies Corporation Method of increasing resistance of flat-panel device to bending, and associated getter-containing flat-panel device
KR100463190B1 (ko) * 2002-06-12 2004-12-23 삼성에스디아이 주식회사 금속 메쉬 일체형 스페이서 구조체 및 이 구조체를 갖는평판 표시 소자
US7106526B2 (en) * 2004-04-21 2006-09-12 Matsushita Electric Industrial Co., Ltd. Thin imaging apparatus, a thin camera, and an imaging method

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4069439A (en) * 1977-02-02 1978-01-17 Rca Corporation Flat panel display with beam injection cleanup
GB2110465A (en) * 1981-11-09 1983-06-15 Philips Electronic Associated Flat panel display tube

Also Published As

Publication number Publication date
DE69108997D1 (de) 1995-05-24
JPH0668815A (ja) 1994-03-11
DE69108997T2 (de) 1995-12-07
EP0464938A1 (en) 1992-01-08
NL9001529A (nl) 1992-02-03
KR920003232A (ko) 1992-02-29
CN1058297A (zh) 1992-01-29

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