JPS60232648A - Cathode-ray tube display device - Google Patents

Abstract

PURPOSE:To produce highly accurate CRT structure where flickering is suppressed even if the driving speed of deflection coil and the control speed of electron beam are not increased so much, in a raster scan cathode-ray tube display device, by scanning simultaneously with plural electron beams in order to perform phosphor display of single color. CONSTITUTION:Focus system or the control grids 3, 3' and the anodes 4, 4' are constructed such that a pair of electron guns 2, 2' are employed to describe the scanning lines 1, 2 simultaneously on a display screen with distance l1 by means of the electron beams 9, 9' projected from said guns 2, 2'. The electron beams 9, 9' are deflected through a deflection coil 7 such that the scanning line is moved by the width l2 which is two times l1 in vertical direction of screen.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to cathode ray tube displays, and more particularly to rask scan cathode ray tube displays.

[Problems with the Prior Art] A conventional cathode ray tube (hereinafter simply referred to as CRT) generally has a structure as shown in FIG.

FIG. 1 shows the structure of a monochrome screen CRT for simplicity. Referring to FIG. 1, first, the rask scanning type C
The operation of RT will be explained.

The CRT has an electron gun 2 and a control grid 3 surrounded by a glass tube 1.
, an anode 4, and a deflection coil 7 wound outside the tube l around its neck. electron gun 2
is composed of a cathode 5 and a heater 6.
is for heating the cathode 5, and when the cathode 5 is heated, it emits electrons. The control grid 3 has a cylindrical shape and is held at a slightly lower potential than the cathode 5.
Electrons emitted from the control grid 3 are repelled by the control grid 3, but some of them pass through the small hole 8 formed at the tip of the control grid 3. Since the anode 4 is held at a high potential with respect to the cathode 5, The electrons are accelerated to form an electron beam 9, and when they collide with the phosphor on the display surface lO of the tube 1, the phosphor emits light. The control grid 3 and the anode 4 are structured to form the electron beam 9 into an extremely thin linear beam and accelerate it toward the display surface 10. The deflection coil 7 deflects the electron beam 9, and is designed to electromagnetically swing the electron beam 9 as desired to scan the phosphor on the display surface, that is, the screen io.

As shown in FIG. 2, the electron beam 9 scans the phosphor by scanning horizontally starting from the upper left of the display surface, that is, the screen 10, from the left edge to the right edge, and when reaching the right edge, moving down by one scanning line. Further, the electron beam 9 is scanned from the left end to the right end while descending in order, and the intensity of the electron beam 9 is appropriately changed by a control device (not shown), thereby changing the amount of light emitted by the phosphor. Graphics, characters, etc. are displayed on a display surface, that is, a screen 10. In the prior art scanning method as shown in FIG. In order to increase the size of one screen and display more precise images, the number of scanning lines must be increased. However, the rask scanning type CRT
In this field, there are many requests to display images that change from moment to moment by using fluorescent materials with relatively short afterglow, so the time to scan an entire screen is limited to about 1/30 seconds. Put it away. Therefore, in order to obtain a large number of scanning lines, the time required to draw one scanning line must be made shorter, and the deflection coil 7 shown in FIG. 1 must be driven for high-speed deflection. As a result, the circuit configuration becomes complicated and the amount of heat generated also increases. Furthermore, the operating speed of the drive circuit that controls the intensity of the electron beam becomes faster, requiring a special circuit.

[Objective of the Invention] The present invention has been made in view of the above-mentioned circumstances in the prior art, and provides a highly accurate CRT structure with less flicker without increasing the drive speed of the deflection coil and the control speed of the electron beam intensity. The purpose is to

According to the present invention, to achieve the above object.

In a scanning cathode ray tube display device that displays fluorescent light in at least one color, a plurality of electron beams are simultaneously generated to display fluorescent light in at least one color, and a plurality of scanning lines are formed at regular intervals on the display screen. Provided is a cathode ray tube display device characterized in that the images are scanned simultaneously.

[Example] The present invention applies not only to CRTs with black and white screens but also to CRTs with color screens.
This also applies to RT, but for simplicity, C on a black and white screen is used.
RT will be explained. FIG. 3 shows the structure of a CRT according to an embodiment of the present invention. In FIG. 0, the same reference numerals and the same reference numerals with a dash as in FIG. 1 represent elements having the same or similar functions.

As can be seen in FIG. 3, the CRT of the invention comprises a pair of electron guns 2.2' similar to the electron guns 2 in FIG. 4
．． 4'. Therefore, electron beams 9 and 9' are emitted from the electron guns 2 and 2', respectively.

[Operation] The operation of the CRT according to the present invention will be explained with reference to FIGS. 3 and 4. According to the present invention, a pair of electron guns 2 and 2' shown in FIG. A focusing system, i.e., a control grid 3.3' and an anode 4.4, are arranged so that the scanning lines of the generated electron beam 9.9' are drawn simultaneously on the display screen at a distance of 1, as shown in FIG. ′
is configured. In FIG. 4, the solid line ■ represents the scanning line by the electron beam 9, and the dotted line ■ represents the scanning line by the electron beam 9'.
The deflection of the electron beam 9.9' by the deflection coil 7 in FIG. 3, which represents the scanning line by , in the vertical direction, as is clear from Figure 4, it is necessary to deflect each electron beam 9.9' so that the scanning line moves by an amount of 2 times the amount of 2 times the amount of 1 that is scanned by the pair of electron beams. . Furthermore, since the pair of electron beams 9 and 9' perform scanning at the same time, a control circuit (not shown) is required to output data for the two electron beams.

In the explanation of the above embodiment, for the sake of simplicity, a pair of electron guns were provided for a CRT with a black and white screen display, and two electron beams were swung simultaneously. However, the present invention is not limited to this. It is clear that the present invention can also be applied to a display CRT, and the number of electron beams to be simultaneously swung is not limited to two, but may be three.

[Effects] Interlaced scanning has been conventionally used to produce effects similar to those of the present invention, but with this scanning, flickering is noticeable especially in the case of CRTs that display figures, characters, etc.
In the case of the present invention, since scanning is performed simultaneously with at least two electron beams, if the vertical synchronization frequency is the same, the horizontal synchronization frequency is at least 112 or less compared to a non-interlaced scanning CRT, and the same size CRT is scanned.
T can be scanned with the same number of scanning lines, thereby achieving the effect of enabling high-precision display without increasing the horizontal synchronous frequency and video frequency too much.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram showing an overview of a conventional CRT.
2 is an explanatory diagram of screen scanning by the CRT shown in FIG. 1, FIG. 3 is a schematic partial configuration diagram showing an outline of a CRT according to an embodiment of the present invention, and FIG. 4 is an explanation of screen scanning by the CRT shown in FIG. 3. It is a diagram. Explanation of symbols 2, 2', ..., electron gun, 3, 3. ,,,Control grid,4.4',,,Anode,7,,,Deflection coil,9,9',,,Electron beam. Agent Patent Attorney Takeo Goto Agent Patent Attorney Iso Karamoto Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] (1) In a raster scanning cathode ray tube display device that performs fluorescent display of at least one color, multiple electron beams are simultaneously generated and spaced apart from each other by a certain distance on the display screen in order to display the fluorescent display of the one color. A cathode ray tube display and device characterized in that the scanning lines of 1 and 2 are simultaneously scanned. (2. In Claim 1, the cathode ray tube display device includes a plurality of sets of electron guns, a control grid, an anode for forming each of the plurality of electron beams, and a control grid for deflecting the electron beams. 1. A cathode ray tube display device comprising a brass electrode ray tube with one deflection coil.