JPH0616378B2 - Image display device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device for displaying image information such as characters and figures by light emission by using gas discharge.

2. Description of the Related Art As shown in FIG. 3, a plurality of strip-shaped cathodes 3a, 3b, 3c ... And a horizontal direction which are long in the vertical direction (Y direction) are provided in a gas discharge space between two glass plates 1 and 2. A large number of strip-shaped anodes 4a, 4b, 4c, which are long in the (X direction), are arranged in a line shape, and a large number of long dielectric barriers 5a, 5 are arranged along the anodes.
A display discharge tube in which b, 5c ... Are disposed between the anodes is well known from Japanese Patent Laid-Open No. 55-14623.

Such a discharge tube is usually manufactured by using a thick film printing technique, and as shown in FIG. 4, strip-shaped anodes 4a, 4b, 4c ... And an auxiliary anode 6a described later are formed on the inner surface of the glass plate 1 on the surface side. , 6b are attached. And the glass plate 2 on the back side
Strip-shaped cathodes 3a, 3b, 3c ... And auxiliary cathodes 7a, 7b which will be described later are provided on the inner surface of the strip-shaped cathodes 3a, 3b,
3c ... Dielectric partition walls 5a, 5b, 5c ... Are additionally provided, and both glass plates 1 and 2 are adhered to a secret by a low-melting glass layer provided on the peripheral edge of the inner surface thereof. A mixed gas of neon and argon and a trace amount of mercury are enclosed in this tube.

Such a matrix-type display discharge tube has various kinds of intersection regions where the cathode and the anode intersect each other, depending on a selective combination of keeping the seed discharge state or the display discharge state. Characters and figures can be displayed by light emission, and the operation principle is as follows.

FIG. 5 shows one strip-shaped anode 4a and five strip-shaped cathodes 3a,
3b ... 3e, an auxiliary anode 6a, an auxiliary cathode 7a, and a circuit member connected to each are representatively shown, and scanning in the X direction is in an off state for the cathode switches 8a, 8b. , 8c ... are sequentially and instantaneously switched to the ON state. When the anode switch 9a is turned on based on the image information signal during the scanning period in which the arbitrary cathode switch is in the on state, the DC power source 1 is provided in the intersection area between the anode 4a and the cathode.
A constant current flows from 0 through the resistor 11 to generate a dot-shaped display discharge. Immediately before the adjacent cathode switch to be scanned is turned on, a blanking period is provided for keeping all the cathode switches off.
Within this blanking period, the anode switch 9a is forcibly turned on. At this time, a charging current flows into the anode stray capacitance 12 and the capacitor 13, and the anode potential is raised to the positive potential of the DC power supply 10. Therefore, next, when the adjacent cathode switch is turned on, if the anode switch 9a is turned off, a pilot fire discharge occurs due to the accumulated charges of the stray capacitance 10 and the capacitor 13. Although this seed discharge is extinguished in a short time, if a seed discharge is generated in the intersection region when the display discharge is not performed, charged particles and excited atoms may be diffused in the next intersection region to be scanned. The display discharge operation can be stably performed without causing discharge or discharge delay. Note that FIG. 5 shows a state in which display discharge is generated on the shades 3a, 3c and 3d and seed fire discharge is generated on the cathodes 3b and 3e. By the way, the auxiliary anode 6a is connected to the positive electrode side of the DC power supply 10 via the resistor 14, and the auxiliary cathode 7a is connected to the negative electrode of the DC power supply 10 via the resistor 15. Then, an auxiliary discharge due to a small current is constantly generated between the auxiliary anode 6a and the auxiliary cathode 7a, and the discharge operation in the intersection region on the cathode 3a which is scanned first by this auxiliary discharge causes erroneous discharge or discharge. It will be started without delay.

Problems to be Solved by the Invention Two auxiliary discharge cells composed of the auxiliary anodes 6a and 6b and the auxiliary cathodes 7a and 7b must be provided in the vicinity of the cathode 3a, and are usually shown in FIG. Thus, it is provided in the vicinity of the intersection region between the anodes 4a and 4i on both sides and the cathode 3a. However, in a discharge tube provided with a large number of anodes, erroneous discharges or discharge delays are likely to occur in the intersection area near the center on the cathode 3a, and if this occurs, unevenness and flicker occur in the luminescent display image. .

Therefore, it is an object of the present invention to provide an image display device capable of producing a good auxiliary discharge in the intersection region over substantially the entire length of the first scanned cathode, even in a discharge tube requiring a large number of anodes. To provide.

Means for Solving the Problems According to the device of the present invention, an auxiliary cathode bus bar adjacent to the cathode group and an auxiliary anode bus line along the bus bar are provided on a glass plate supporting the strip cathode group. At the same time, a plurality of pairs of auxiliary cathodes and auxiliary anodes, which are respectively connected to both buses and form auxiliary discharge cells, are provided.

Operation With such a configuration, it is possible to lay long auxiliary cathode busbars and auxiliary anode busbars without directly crossing the strip-shaped anode group, and it is possible to install many auxiliary discharge cells everywhere between both busbars. Becomes

EXAMPLE The discharge tube of the device for carrying out the present invention shown in FIG. 1 is different from the conventional discharge tube shown in FIG. 4 in that it is located on the inner surface of the glass plate 2 on the rear side and the first band A strip-shaped auxiliary cathode busbar 16 along the cathode 3a and a strip-shaped auxiliary anode busbar 17 along the busbar 16 are provided, and the auxiliary cathode busbar 16 is connected via the resistance elements 18a and 18b. Auxiliary cathodes 19a and 19b are provided, and auxiliary anodes 21a and 21b connected to the auxiliary anode bus bar 17 via resistance elements 20a and 20b are provided near the auxiliary cathodes 19a and 19b. , The busbars 16 and 17 and the resistance elements 18a, 18b, 20a and 20b are covered with the insulating layer 22, and the insulating layer among the strip-shaped anodes 4a, 4b and 4c on the inner surface of the front side glass plate 1. 22 is the insulating layer Sequence by the point that is covered by 3, other structures are substantially the same.

The auxiliary cathode busbar 16 and the auxiliary anode busbar 17 are long along the first strip-shaped cathode 3a, and therefore both busbars 1
Any number of auxiliary discharge cells composed of auxiliary cathodes and auxiliary anodes connected between 6 and 17 via respective resistance elements can be provided depending on the number of anodes.

According to the configuration of the illustrated example in which the auxiliary cathodes 19a and 19b are formed in a semi-circular shape and the tips of the auxiliary anodes 21a and 21b are located at the center thereof, not only can the discharge of the auxiliary discharge cells be smoothly started. The discharge can be stably maintained, and a good discharge operation can be obtained even though the auxiliary cathode and the auxiliary anode are present on the common glass plate.

It is sufficient to directly apply a DC power source voltage of 200 V, the former of which is negative, to the auxiliary cathode bus 16 and the auxiliary anode bus 17, but the auxiliary discharge cells can start and sustain discharge better. It is desirable to configure the circuit as
An example thereof is shown in FIG. The circuit configuration shown in the figure differs from the conventional circuit configuration in that the auxiliary cathode bus bar 16 provided in the discharge tube is connected to the negative electrode of the 200 V DC power supply 10, and the auxiliary anode bus bar 17 is the output of the booster circuit 24. Terminal 25
Is connected via a resistor 26.

The booster circuit 24 receives a cathode switch (scanning) clock pulse (15 KHz to 25 KHz) generated by the control circuit 27 as an input signal and performs a switching operation. A transistor 28, a collector of the transistor 28 and a positive electrode of a 5V DC power supply 29. And a choke coil 30 connected between the output terminal 25 and a diode 31 connected in the forward direction between the collector and the output terminal 25, and a smoothing capacitor 32 connected between the output terminal 25 and the ground point.

According to such a circuit configuration, when the transistor 28 is turned on, a current flows through the choke coil 30 so that the collector of the transistor 28 becomes substantially at the ground potential. Then, when the transistor 28 is turned off, the choke coil 30 generates. Since the induced voltage is taken out to the output terminal 25 through the diode 31, a rectified voltage of 100 V at the maximum can be obtained at the output terminal 25. Since the resistor 26 is provided, the output voltage is directly applied to the auxiliary anode between the time when the power switch is turned on and the time when the auxiliary discharge is started, and a voltage drop is given after the auxiliary discharge is started. The potential of the bus for the anode can be lowered to a value necessary for sustaining the discharge, the auxiliary discharge can be smoothly started, and the dielectric breakdown between the two buses can be prevented.

The resistance elements 18a, 18b ... And the resistance element 20
Either one of a, 20b ... Can be omitted.

EFFECTS OF THE INVENTION Since the present invention is configured as described above, a display image due to an erroneous discharge or a discharge delay, which has been apt to occur in a display device having a high definition requiring a large number of band-shaped anodes or a large-screen display, has conventionally been generated. It is possible to eliminate the unevenness of flicker and the occurrence of flicker.

[Brief description of drawings]

FIG. 1 is a developed perspective view of a main part of a discharge tube of an image display apparatus embodying the present invention, FIG. 2 is a drive circuit diagram of the apparatus, and FIG. 3 is a perspective view of a part of a conventional display discharge tube. FIG. 4 is a developed perspective view of a part of the discharge tube, and FIG. 5 is a circuit diagram for explaining the operation principle of the discharge tube. 3a, 3b ... band-shaped cathode, 4a, 4b ... band-shaped anode, 1
6, 17 ... Bus bar, 19a, 19b ... Auxiliary cathode, 21
a, 21b ... Auxiliary anode.

Claims (1)

[Claims] 1. A discharge tube having a strip-shaped cathode group arranged in one direction, a strip-shaped anode group intersecting the cathode group through a gas discharge space, and an auxiliary discharge cell, and the cathode group are sequentially turned on. Along with the anode group is selectively turned on potential according to the image information signal, comprising a drive circuit for firing the auxiliary discharge cells at the time of startup, the glass plate supporting the cathode group is the same cathode group. Auxiliary cathode busbars arranged adjacent to each other in one direction and auxiliary anode busbars arranged along the same busbar are additionally provided, and the auxiliary discharge cells are formed by being respectively connected to both busbars. An image display device comprising a plurality of pairs of an auxiliary cathode and an auxiliary anode.