JPH0714531A - Fluorescent character display device - Google Patents

Abstract

PURPOSE:To prevent the erroneous luminescence of a nonselection section by adding at least one or more dummy linear grids on both outsides of a phosphor dot group in a fluorescent character display device having a double matrix structure connected with display section anodes in odd lines and even lines. CONSTITUTION:An anode electrode 2 made of an aluminum thin film is formed on a glass substrate 1. A graphite layer 3 and a phosphor layer are formed on the anode 2. The phosphor layer is removed from a dummy anode 7. Grids 5 are suspended on the anode 2, and filaments 6 perpendicular to them are suspended. Dummy grids 8 are suspended on both sides of the dummy anode 7. Two grid voltage 4G, 5G are superposedly applied in sequence to odd line anodes P1A-P5A and even line anodes P1B-P5B in turn, and phosphors are illuminated by the thermoelectrons emitted from the filaments 6. The grid voltage 2G, 3G, (m-1)G, (m-2)g are kept at the same timing, thus no nonselection luminescence is generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent display device for electrically heating a filament, extracting thermoelectrons into a vacuum, accelerating them with a grid and colliding them with an anode coated with a phosphor to excite the phosphor to emit light. Among them, the present invention relates to the structure of a dual matrix type fluorescent display device applied to full graphic display.

[0002]

2. Description of the Related Art A conventional dual matrix type fluorescent display device applied to full graphic display is disclosed in Japanese Patent Application No. 3-1405.
Generally, the structure and driving method described in Japanese Patent No. 46 are adopted (see FIGS. 3A to 3C).

The dual matrix type fluorescent display device will be described below. As shown in FIGS. 3 (a) and 3 (b), one row of anodes has two sets of odd columns and even columns (for example, the first row is P1).
The second row of A and P1B is designated as P2A and P2B. ), And the grid is provided between the anode dots. When driving, two grids sandwiching the anode dot are simultaneously selected and emitted. This drive will be described below. As in the timing of FIG. 3C, first, a voltage is applied to the grid 3G and the grid 4G for a certain time, and at this time, the odd-numbered column anodes P1A to P1A to P sandwiched between the grid 3G and the grid 4G.
By applying a positive voltage to 5A, the thermoelectrons emitted from the filament are transferred to the grid 3G and the grid 4 described above.
It is accelerated by G, and the phosphor coated on the electrodes of the odd-numbered-row anodes P1A to P5A is excited to emit light. Next grid 4G
And a voltage is applied to the grid 5G and the even-numbered column anodes P1B to P1P
A positive voltage is applied to 5B to cause the even column anodes P1B to P5B to emit light. By repeating the above in sequence, the odd-numbered anode rows and the even-numbered anode rows are alternately emitted to obtain a desired display.

[0004]

According to the method of driving the grid electrodes of the conventional dual matrix type fluorescent display device, when the grid 3G and the grid 4G are selected, the grid 3G and the grid (m-2) G are They are connected and driven at the same potential. Therefore, when the grid 3G and the grid 4G are selected and the odd-numbered column anodes (or the grid (m-3) G and the grid (m-4) G are selected to emit the even-numbered column anodes), a in FIG. As shown in FIG. 3B, which is a sectional view taken along the line aa ′, an unselected odd-numbered column anode sandwiched between the grid (m-4) G and the grid (m-3) G (or the grid 4).
There was a problem that even-numbered column anodes sandwiched between G and the grid 5G emitted light.

[0005]

According to the fluorescent display device of the present invention, in the dual matrix type fluorescent display device, at least one dummy linear grid is provided on both outer sides of the anode of the display portion composed of phosphor dot groups. In addition, a fluorescent display device characterized by adding a dummy anode having at least one or more rows of phosphors on both outer sides of the phosphor dot group and positions on both sides of the dot row at both ends of the phosphor dot group. The fluorescent display device is characterized in that it has means for applying the same drive voltage at the same timing to the two linear grids forming a pair with the two linear grids as a pair.

[0006]

The present invention will be described below with reference to the drawings.

1 (a) and 1 (b) are a schematic diagram of an electrode structure of a fluorescent display device according to a first embodiment of the present invention, and a cross-sectional schematic diagram for explaining the operation.

In the anode substrate of the present invention, an anode electrode 2 made of an aluminum thin film is formed on a glass substrate 1 by a combination of a sputtering method and an etching method. The anode electrode 2 is formed in a double matrix structure in which the odd columns of each display row are A and the even columns are B. (In FIGS. 1A and 1B, the display rows are numbered P1, P2, ... P5 from top to bottom.) Subsequently, the insulating layer (FIG. 1) is formed on the glass substrate 1. (Omitted in (a) and (b)) was formed by a film thickness technique. Further, a graphite layer 3 and a phosphor layer 4 were formed on the anode electrode 2 by a film thickness technique. After this, SUS
304 or grid 5 made of SUS430
Was stretched between the anode electrodes 2, and a filament 6 having a tungsten wire coated with a (Ba, Sr, Ca) O film was stretched so as to be orthogonal to the anode electrode 2. The structure characteristic of the present invention is shown in A'or B '. This is because the dummy anode 7 not covered with the phosphor layer 4 is provided, the dummy grids 8 are stretched on both sides of the dummy anode 7, and the grids are connected. The dummy anode 7 was formed simultaneously with the formation of the anode 2, and was realized by omitting the step of forming the phosphor layer.

Next, a second embodiment is shown in FIG. The anode electrode 2, the graphite layer 3, and the anode layer 2 were manufactured by the same method as in the first embodiment.
The phosphor layer 4 was formed and the grid 5, the dummy grid 8 and the filament 6 were stretched. The present embodiment is characterized in that two dummy grids 8 are mounted on each of the two outer sides of the anode 2 group, a total of four, are grounded, and two grids 5 sandwiching the anodes 2 at both ends are connected.

In the embodiments shown in FIGS. 1 and 2, the drive waveforms are shown in FIGS. 1 (c) and 2 (c), respectively.

[0011]

According to the present invention described above, the electrons emitted from the filament 6 as shown in the sectional views of FIGS. 1 (b) and 2 (b) are accelerated by the grid 5 to cause fluorescence on the anode 2. Guided to the body layer. According to the present embodiment, since the closest anode 2 of the selected grid 5 has a structure and timing that is always selected, it is possible to prevent the conventional non-selected part from emitting light.

[Brief description of drawings]

FIG. 1 is a schematic plan view (a), an aa ′ sectional view (b) and a drive waveform diagram (c) of an electrode structure according to a first embodiment of the present invention.

FIG. 2 is a schematic plan view (a), a bb ′ sectional view (b) and a drive waveform diagram (c) of an electrode structure according to a second embodiment of the present invention.

FIG. 3 is a schematic plan view (a), a cc ′ cross-sectional view (b) and a drive waveform diagram (c) of an electrode configuration of a conventional fluorescent display device.

[Explanation of symbols]

 1 Glass Substrate 2 Anode Electrode 3 Graphite 4 Phosphor Layer 5 Grid 6 Filament 7 Dummy Anode 8 Dummy Grid

Claims (3)

[Claims] 1. An anode substrate, a phosphor dot group formed in a matrix on the anode substrate, and a linear grid arranged at a distance from the anode substrate on both sides of a row of the phosphor dot group. In addition, in a fluorescent display device having a double matrix structure in which display anodes composed of the phosphor dot groups are connected in odd and even columns, at least one dummy is provided on both outsides of the phosphor dot groups. A fluorescent display device characterized in that a linear grid of is added. 2. The fluorescent display device according to claim 1, wherein dummy anodes having no phosphor in at least one row are added to both outer sides of the phosphor dot group. 3. The same drive voltage is applied at the same timing to the two linear grids forming a pair by forming a pair of the two linear grids located on both sides of a dot row at both ends of the phosphor dot group. The fluorescent display device according to claim 1, further comprising: