JPS6313193B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for driving a fluorescent display tube that provides a high dot display density and a good luminescent display without missing characters.

FIG. 1 is a plan view showing a conventional fluorescent display tube, particularly showing the arrangement relationship between an anode electrode and a grid electrode. As an example, a dot matrix fluorescent display tube with m columns and n rows will be shown. In the same figure, A ₁₁
~A _1n , A ₂₁ ~A _2n , ......A _o1 ~A _on are m×n dot-shaped anode electrodes arranged in a matrix of m columns and n rows, and G ₁ ~ _{G n} are anodes in each column. electrode
A ₁₁ to A _1n , A ₂₁ to A _2n , . . . A _o1 to A _on are respectively provided with m grid electrodes commonly facing each other, 1a to 1n are anode electrodes of each row A ₁₁ to _{A 1n} ,
A ₂₁ to _{A 2n} , ...... Lead wires that commonly connect A _o1 to A _on , 2a to 2n are anode electrode extraction terminals of these lead wires 1a to 1n, and 3a to 3m are grid electrodes G ₁ to G _n, respectively. This is a grid electrode lead-out terminal that connects to.

The conventional method for driving a fluorescent display tube configured as described above is to sequentially apply grid scan pulses shown in FIGS. 2a to 2d to each of the m grid electrodes _G1 to _Gn , and By applying a signal to the anode electrodes A ₁₁ to _{A on} in synchronization with this grid scan pulse, the dot segments emit light to display desired characters or symbols.

However, in the conventional method of driving a fluorescent display tube, as shown in _FIG . Lead wire 1l _-1 ,
An erase voltage is applied to 1l ₊₁ . On the other hand, a lighting voltage is applied to the grid electrode Gk, and an erasing voltage is applied to the other grid electrodes Gk _-1 , Gk ₊₁ , etc. As a result, the anode electrode A _lk emits light, but
As shown in FIG. 3, there was a drawback in that a missing portion 4 of characters appeared in the light emission of the segment.

Therefore, in order to prevent this missing part 4 from occurring, as shown in FIG. Letting S be the distance from one end of the anode electrode, the following formula holds true.

S=P-D/2-W/2=P-(D+
W)/2 From this equation, it was confirmed through experiments that S must be approximately 2.5 mm or more. Therefore, with conventional fluorescent display tubes, it is impossible to display a high dot display density, for example, a 1 mm pitch fluorescent display tube, without causing missing characters.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a fluorescent display tube that has a high dot display density and provides good light emission without missing characters, and a method for driving the same.

In order to achieve such an objective, this invention
m×n anode electrodes arranged in a matrix of n columns and n rows and commonly connected to the anode electrodes in the odd columns and the anode electrodes in the even columns in each row, and commonly opposed to the n anode electrodes in each column. It is equipped with m grid electrodes arranged as shown in FIG. Then, sequential scan pulses are applied simultaneously to three adjacent grids, and a light emission selection signal is synchronized with the grid scan pulse to the anode electrode corresponding to the central grid of the three grids. This will be explained in detail below using examples.

FIG. 5 is a plan view showing one embodiment of the fluorescent display tube according to the present invention, particularly showing the relationship between the anode electrode and the grid electrode. In the same figure, 5a ₁ to 5
n ₁ are the anode electrodes A ₁₁ , _A 13 , ~A 1n-1 , A ₂₁ , A 21 , A 13 , A 13 , ~A 1n-1 , A 21 , A 21 , A 13 , A 13 , A 13 , A 13 , A 13 , A 13 , A 13 , A 21 , A 13 , A 13 , A 13 , A 13 , A 11 , A 13 , A 13 , A 13 , A 21 , A 13 , A 13 , A 11 , A ₁₃ , A 13 , A 13 , n 1 , A 11 , A 13 , A 11 , A 13 , A 11 , A ₁₂ , _{n 1} , n 1 , respectively.
A ₂₃ , 〜A _2n-1 〜A _o1 , A _o3 〜A _on-1 are connected in common to odd-numbered row lead wires, and 5a ₂ 〜5n ₂ are the anodes of even-numbered columns among the anode electrodes A ₁₁ 〜A _on, respectively. electrode
A ₁₂ , A ₁₄ ~ _{A 1n} , A ₂₂ , A ₂₄ ~A _2n ~A _o2 , A _o4 ~
Even-numbered row lead wires commonly connected to A _on , 6a ₁ to 6
n ₁ are first anode electrode extraction terminals connected to the odd-numbered column lead wires 5a ₁ to 5n ₁ , respectively, and 6a ₂ to 6n ₂ are second anode electrode extraction terminals connected to the even-numbered column lead wires 5a ₂ to _{5n 2} , respectively.
This is an anode electrode lead terminal.

Next, the display operation of the fluorescent display tube according to the above structure will be explained with reference to FIG.

First, as shown in FIG. 6, when emitting light from the anode electrodes A ₃₄ arranged in 3 rows and 4 columns, for example, a lighting voltage is applied to the even-numbered column lead wires 5c ₂ in FIG. 5, and the remaining odd-numbered column lead wires 5a ₁ ~5n ₁ and even sequence 5a ₂ , 5
An erase voltage is applied to b ₂ , 5d ₂ to 5n ₂ . On the other hand, applying a lighting voltage to grid electrodes G ₃ , G ₄ and G ₅ ,
A light-off voltage is applied to the remaining grid electrodes G ₁ , G ₂ , G ₆ , . . . . As a result, the anode electrode A ₃₂ ,
Since a lighting voltage is applied to A ₃₄ , to A _3n and a lighting voltage is applied to the grid electrodes G ₃ , G ₄ and G ₅ , only the anode electrode A ₃₄ emits light.

Next, FIG. 7 is a block diagram showing an embodiment of the method for driving a fluorescent display tube according to the present invention. In the figure, 7 is a scan counter, 8 is a decoder for decoding the contents of this scan counter 7,
9 is an anode driver that drives the odd-numbered column lead lines 5a ₁ to 5n ₁ and the even-numbered column lead lines 5a ₂ to 5n ₂ , respectively; 10 is a data source; 11 is a grid driver; and 12 is a detailed circuit thereof shown in FIG. This is a distribution circuit shown in FIG.

Note that in the distribution circuit 12 shown in FIG.
3a to 13n are diodes, respectively.

Next, the operation of the method for driving the fluorescent display tube according to the above structure will be explained with reference to FIGS. 9a to 9d.

First, when the scan counter 7 operates, the decoder 8 decodes the contents of the scan counter 7. Therefore, the anode driver 9 operates upon receiving the output of the decoder 8, and simultaneously energizes the odd-numbered column lead lines 5a ₁ to 5n ₁ and the even-numbered column lead lines 5a ₂ to 5n ₂ . For this reason, the anode electrode A ₁₁ ~
At the same time, lighting voltage is applied to A _on . On the other hand, the grid driver 11 operates according to the data signal output from the data source 10. Due to the operation of this grid driver 11, first, when a lighting voltage is output to the output terminal 11a, this lighting voltage is applied to the diode 1.
3a and 13b to the grid electrode extraction terminals 3a and 3b, so the grid electrode
C ₁ and C ₂ are applied at time t ₁ shown in FIGS. 9a and 9b. Therefore, the anode electrode located at the intersection of the anode electrode to which the lighting voltage is applied and the grid electrode to which the lighting voltage is applied emits light. Next, when a lighting voltage is output to the output terminal 11b, this lighting voltage is applied to the diodes 13c, 1
3d and 13e to the grid electrode extraction terminals 3a, 3b and 3c, the grid electrodes G ₁ , G ₂ and G ₃ are connected to Figs. 9a to 9c.
is applied at time t ₂ shown in . Therefore, the anode electrode located at the intersection of the anode electrode to which the lighting voltage is applied and the grid electrode to which the lighting voltage is applied emits light. Thereafter, the desired anode electrode emits light in the same manner.

In addition, although the case where n×m dot-shaped anode electrodes are arranged in n rows and m columns and lighting is performed by grid scan has been described above, it is needless to say that the present invention is not limited to this.

In addition, in the case of nm, it is advantageous to light by grid scan, but in the case of n In some cases, by alternately inputting signals to odd-numbered segments and even-numbered segments in the same row, lighting can be performed by segment scanning using a duty factor of 1/2n.

As described above in detail, the method for driving a fluorescent display tube according to the present invention has the effect of making it possible to make the dot display density extremely high and to obtain good light emission without missing characters.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the arrangement relationship between the anode electrode and grid electrode of a conventional fluorescent display tube, and Fig. 2a
~Fig. 2d is a diagram showing the grid scan pulse applied to the grid electrode in Fig. 1, Fig. 3 and Fig. 4 are diagrams for explaining the light emitting display operation of Fig. 1, and Fig. 5 is a diagram showing the grid scan pulse applied to the grid electrode in Fig. 1. FIG. 6 is a plan view showing an embodiment of the fluorescent display tube according to the present invention, particularly showing the arrangement relationship between the anode electrode and the grid electrode, and FIG. 6 is a plan view of the fluorescent display tube for explaining the light emitting display operation of FIG. FIG. 7 is a block diagram showing an embodiment of the fluorescent display tube driving method according to the present invention, FIG. 8 is a circuit diagram showing the distribution circuit of FIG. 7, and FIGS. FIG. 9d is a diagram showing grid scan pulses applied to the grid electrodes of FIG. 5, respectively. A ₁₁ ~ _{A on} ...Anode electrode, _G1 ~ _Gn ...Grid electrode, 1a~1n...Lead wire, 2a~2n
...Anode electrode lead-out terminal, 3a to 3n... Grid electrode lead-out terminal, 4... character missing part, 5a ₁
~ _5n1 ...Odd number row lead wire, _5a2 ~ _5n2 ...Even number row lead wire, _6a1 ~ _6n1 ...First anode electrode extraction terminal, _6a2 ~ _6n2 ...Second anode electrode extraction terminal, 7...Scan counter, 8...Decoder, 9...Anode driver, 10...Data source, 11...Grid driver, 12...Distribution circuit, 13a-13n...Diode.

Claims (1)

[Claims] 1 m×n anode electrodes arranged in a matrix of m columns and n rows and commonly connected to the anode electrodes in the odd columns and the anode electrodes in the even columns in each row, and the anode electrodes in common to the n anode electrodes in each column. In a fluorescent display tube equipped with m grid electrodes arranged to face each other, a total of three grid electrodes, the grid electrode facing the anode electrode that emits light and the grid electrodes adjacent on both sides of this grid electrode, are simultaneously formed as a pair. While energizing the signal, scan pulses are sequentially applied, and in synchronization with the scan pulses, n even-column anode electrodes and n odd-column anode electrodes are alternately selected. A method for driving a fluorescent display tube, characterized in that a light emission selection signal is applied to supply a lighting voltage to only the anode electrodes which are to be emitted from among the anode electrodes, thereby displaying desired characters, symbols, etc. by light emission.