JPH06162967A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To make the external shape of a cathode-ray tube compact and thin. CONSTITUTION:This cathode-ray tube internally has the first plane 14 and the second plane 18 formed on a phosphor screen 16, laid in such a way as faced to each other, and a vacuum sealed envelope 12 is used to provide a cathode 22 capable of emitting electrons at a large wide angle near the first plane 14. In addition, a flat body 34 made of insulation material having a matrix of many transmission holes 32 is laid forward of the cathode-ray tube 22. Also, the internal surface of each hole 32 and/or the edge thereof is provided with control electrodes 36 selectable to allow the transmission of electrons, depending upon applied voltage. In addition, an anode 44 is formed on the second plane 18. According to this construction, electrons emitted from the cathode 22 pass only the selected electrode 36 and reach the anode 44, thereby causing the phosphor screen 16 to be luminous.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube, and more particularly to a cathode ray tube which can be made thin.

[0002]

2. Description of the Related Art A conventional cathode ray tube is widely used in televisions, oscilloscopes for observing waveforms, etc. For example, a cathode ray tube used in a general television has an outer shape as shown in FIG. The inside is hollow and vacuum-tight. The internal structure will be described. Reference numeral 100 denotes a neck portion. Inside the neck portion 100, an electron gun including a heater 102, a cathode (cathode) 104, and a control grid (grid) 106 is built. It should be noted that the number of electron guns is three for RGB in the case of a color television, and one in the case of an oscilloscope since it may be a single color. This electron gun is heated by the heater 102, and the cathode 10
4 has a function of extracting the thermoelectrons emitted from the laser beam 4 as a beam bundle 108 by adjusting the voltage of the control grating 106. Further, a fluorescent material is applied to the inner wall surface of the tube surface 110 for displaying an image to form a fluorescent surface 112, and the fluorescent surface 112 is thinly metal-plated to form an anode 114. With this configuration, the beam bundle 108 taken out from the electron gun is accelerated by the anode voltage, and the phosphor screen 112 is accelerated.
When it hits, the phosphor emits light in a dot shape. Further, the beam bundle 108 is deflected in the horizontal and vertical directions by the deflection yoke 116 and the like to be scanned, thereby displaying an image on the tube surface 110.

[0003]

However, in the above-mentioned cathode ray tube, the beam bundle extracted from the electron gun built in the neck portion must be scanned over the entire tube surface by the magnetic field generated by the deflection yoke. However, there is a problem in that the distance from the electron gun to the tube surface becomes long, which makes the outer shape large and thick. Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a cathode ray tube which can have a small outer shape and a thin shape.

[0004]

The present invention has the following constitution in order to achieve the above object. That is, it has a vacuum-tight envelope having a first surface and a second surface facing each other, which face each other, and a vacuum-tight envelope. And a cathode capable of emitting a plurality of holes, which are formed in a plate shape using an insulating material, and have a large number of through holes formed in a matrix shape, and a plate-like body provided in front of the cathode and the through holes. It is characterized by comprising a control electrode provided on an inner peripheral surface and / or an edge portion and capable of selectively passing the electrons according to an applied voltage, and an anode formed on the second surface.

[0005]

The electrons emitted broadly from the cathode provided close to the first surface inside the envelope are perforated in a matrix form in the plate-like body, and the inner peripheral surface and / or the edge part are provided with the electrons. Electrons can selectively pass through a large number of through holes provided with control electrodes according to the voltage applied to the control electrodes, and the passed electrons linearly reach the second surface on which the anode is formed. . Since the second surface is formed as a fluorescent screen, the portion reached by the electrons emits light.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partially cutaway perspective view showing an outline and an internal schematic structure of an embodiment of a cathode ray tube according to the present invention. FIG. 2 is a front view of the control grid used in FIG. 1, and FIG. 2A is a first control grid for selecting a control electrode in a row direction among control electrodes in a matrix,
(B) is a second control grid for selecting control electrodes in the column direction among the control electrodes in a matrix. FIG. 3 is a front view of the insulator used in FIG. FIG. 4 is a cross-sectional view taken along the line AA showing the detailed internal structure of FIG. FIG. 5 is a front view showing the structure of the cathode used in FIG. Figure 6
FIG. 7 is an explanatory view showing the structure of an example of a conventional cathode ray tube.

First, the construction of the cathode ray tube of this embodiment will be described with reference to FIGS. 1, 2, 3, 4, and 5.
Reference numeral 10 denotes a cathode ray tube, the outer shape of which is formed in a rectangular parallelepiped having a thin thickness T (see FIG. 1). Further, 12 is an envelope, the inside of which is formed hollow and the inside of which is formed a second surface 1 on which a first surface 14 and a fluorescent surface 16 which face each other are formed.
8 and is vacuum-tight. In addition, 19 is the envelope 1
The sealing material 19 is a sealing material for sealing the second opening, and resin, glass, ceramics or the like is used as the sealing material 19. Reference numeral 20 is a conductive shield material provided on the first surface 14. The shield material 20 is connected to the ground potential when the cathode ray tube 10 is in operation. This shield material 20 enables efficient transfer of electrons from the cathode to the anode described later. Reference numeral 22 denotes a cathode, which is composed of a pair of support rods 24 formed of a conductor and a plurality of heating wires 26 stretched between the support rods 24. The heating wire 26 is formed using a cathode material (thorium tungsten as an example). Further, the cathode 22 is provided close to the first surface 14, and when the current flows to generate heat, the electrons can spread and emit electrons (see FIG. 5). Also,
One of the support rods 24 is provided with a getter container 28, and a metal having a strong activity against gas such as barium and titanium is put in the getter container 28 as a getter material to raise the inside of the envelope 12. The vacuum is maintained.

Reference numeral 30 denotes a first control grid formed to have substantially the same size as that of the phosphor screen 16. The first control grid 30 is made of an insulating material in a rectangular plate shape and has a large number of transparent plates. The plate-shaped body 34 having the holes 32 formed in a matrix, and the cylindrical control electrode 36 provided on the inner peripheral surface and the edge of each through hole 32 are provided in front of the cathode 22. Has been. In addition, each control electrode 3 arranged in a matrix
6 are connected in common to each row (composed of n rows) by, for example, a printed wiring (see FIG. 2a), and the phosphor screen 16 is provided.
Over the entire surface. 38 is the second control grid,
The second control grid 38 has substantially the same configuration as the first control grid 30 and is provided in front of the first control grid 30.
Further, the control electrodes 36 arranged in a matrix are commonly connected to each column (composed of m rows) by, for example, a printed wiring or the like (see FIG. 2B). The control electrode 3
6 may be provided only on the inner peripheral surface of the through hole 32, or may be provided only on the edge portion. Further, the control electrode 36 may be formed as a through hole used for a printed board. Further, 40 is an insulating plate formed in a quadrangle using an insulator, and the insulating plate 40 is provided in front of the first control grid 30 and the second control grid 38, respectively. It should be noted that the insulating plate 40 is provided with matrix-shaped circular holes 42 corresponding to the large number of through holes 32 formed in the plate-shaped body 34.
It is more preferable that the diameter of the circular hole 42 is slightly smaller than the inner diameter of the control electrode 36.

Reference numeral 44 is an anode, and the anode 44 is arranged in front of the second control grid 38 via an insulating plate 40. The phosphor screen 16 is formed by applying one kind of phosphor to the second face 18, and the anode 44 is formed by applying a metal material such as iron or the like to the phosphor screen 16 or by plating. May be. Further, since the cathode 22 passes an electric current to generate heat, a space is provided between the cathode 22 and the first control grid 30 and between the cathode 22 and the shield material 20.

Reference numeral 46 denotes an anode power source for applying a DC voltage higher than the voltage applied to the first control grid 30 and the second control grid 38 to the anode 44. 48 is
It is a cathode power supply as an AC power supply for supplying a current to the cathode 22, a transformer 50 is used in the output stage, and the center of its secondary winding is connected to the ground potential.
As another example of the cathode power source, an oscillation circuit capable of outputting two pulse waveforms whose phases are 180 degrees out of phase with each other may be used. Reference numeral 52 is a control unit, and the control unit 52 controls the control electrodes 36 of the first control grid 30 and the second control grid 38.
It has a function of generating a control signal to be applied to.

Next, the operation of the cathode ray tube having the above structure will be described with reference to FIGS. 2 and 4. First, the shield material 20 is connected to the ground potential, and the anode power source 46 is connected to the anode 44 to set the potential of the anode 44 to + V1. Also,
A cathode power source 48 is connected to the cathode 22, and an alternating voltage is applied to the cathode 22 to cause a current to flow through the heating wire 26 to generate heat. As a result, the heating wire 26 generates heat from the cathode 22 to emit electrons. The peak voltage V2 of the AC voltage applied to the cathode 22 is set as in the following formula. V1> | V2 |> 0 [volt]

At this time, if the voltage value V3 of the control signal output from the controller 52 is set as in the following equation (hereinafter referred to as the first control voltage), the electrons emitted from the cathode 22 are First control grid 30 and second control grid 38
Passing through the inside of each control electrode 36 to reach the anode 44 linearly, whereby the phosphor screen 16 to which the electrons have reached emits light. It should be noted that when the voltage value V3 is increased or decreased within the range of the following formula, the energy at which the electrons reach the fluorescent screen 16 changes, and the emission brightness of the fluorescent screen 16 can be changed. V1>V3> | V2 | Further, the voltage value V3 of the control signal output from the control unit 52.
Is set as in the following equation (hereinafter referred to as the second control voltage), the electrons emitted from the cathode 22 pass through the control electrodes 36 of the first control grid 30 and the second control grid 38. It does not pass through and therefore the phosphor screen 16 does not emit light. In order to reliably prevent the passage of electrons, the voltage value V3 may be set to 0 volt or less. | V2 | >> V3

Next, the voltage of the control signal output from the control unit 52 is changed so that the first control grid 3 through which the electrons pass.
A method of selecting the control electrodes 36 of the 0 and second control grids 38 will be described with reference to FIG. First, for example, second
When only the phosphor screen 16 corresponding to the second row and the second row is made to emit light, the second control electrode 36 and the second control electrode 36 of the first control grid 30 are arranged.
The control signal of the first control voltage is input only to the control electrodes 36 in the second column of the control grid 38 of FIG. 3, and the control signal of the second control voltage is input to all the other control electrodes 36. As a result, electrons pass only within the control electrode 36 corresponding to the intersection of the control electrode 36 forming the second row of the first control grid 30 and the control electrode 36 forming the second column of the second control grid 38. , Second
The fluorescent screen 16 corresponding to the second column of the row emits light. Thus, an arbitrary control electrode 36 through which electrons can pass is selected from the (n × m) matrix control electrodes 36 formed of the first control grid 30 and the second control grid 38. The fluorescent screen 16 can emit light.

If the phosphor screen is composed of three types of phosphors (phosphors that appear red, green, and blue when emitting light), color display is possible. Further, the outer shape of the envelope may be a thin cylinder having a hollow inside, instead of the above rectangular parallelepiped. Further, if the control signal output from the controller is used as a pulse and the phosphor screen is made to dynamically emit light by utilizing the afterglow property of the phosphor, the life of the phosphor can be extended. Further, the number of control grids may be one as long as wiring is provided so that control signals can be individually applied to many control electrodes.

Although various preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and many modifications can be made without departing from the spirit of the invention. Of course.

[0016]

With the use of the cathode ray tube according to the present invention, the electrons emitted from the cathode provided close to the first surface inside the envelope are spread out in a matrix form on the plate-like body. It is possible to selectively pass through a large number of through holes having control electrodes provided on the inner peripheral surface and / or the edge portion thereof in accordance with the applied voltage to the control electrodes, and the passed electrons are linearly moved. Since it reaches the second surface on which the anode is formed and the second surface is formed on the fluorescent surface, the portion on which the electron reaches emits light. This makes it possible to shorten the distance from the cathode to the anode because it is not necessary to deflect and scan the electrons, and it is possible to achieve a remarkable effect that the outer shape can be made smaller and thinner.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an outline and an internal schematic structure of an embodiment of a cathode ray tube according to the present invention.

FIG. 2 is a front view of the control grid used in FIG. 1, where (a) is a first control grid for selecting control electrodes in a row direction among control electrodes in a matrix, (b). Is a second control grid for selecting a control electrode in the column direction among the control electrodes in a matrix.

FIG. 3 is a front view of an insulator used in FIG.

FIG. 4 is a cross-sectional view taken along the line AA showing the detailed internal structure of FIG.

5 is a front view showing the structure of the cathode used in FIG. 1. FIG.

FIG. 6 is an explanatory diagram showing the structure of an example of a conventional cathode ray tube.

[Explanation of symbols]

 Reference Signs List 10 cathode ray tube 12 envelope 14 first surface 16 fluorescent surface 18 second surface 22 cathode 32 through hole 34 plate-like body 36 control electrode 44 anode

Claims (1)

[Claims] 1. A vacuum-tight envelope having a first surface and a second surface formed on a fluorescent surface, which face each other, and is provided close to the first surface. A cathode capable of emitting electrons with a spread; a plate-shaped body formed of an insulating material and having a large number of through holes formed in a matrix; and a plate-shaped body provided in front of the cathode, A control electrode provided on an inner peripheral surface and / or an edge portion of the through hole and capable of selectively passing the electrons according to an applied voltage, and an anode formed on the second surface. And a cathode ray tube.