JPH0648424B2 - Fluorescent display tube drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent display tube drive device capable of driving a fluorescent display tube by any of a static drive, a dynamic drive, and a duplex drive.

[Conventional technology]

As a method (driving method) for driving the fluorescent display tube,
Currently, there are three known dynamic drive systems, static drive systems, and duplex drive systems.

As shown in FIG. 8, the dynamic driving method is such that corresponding ones of the anode electrodes 41 are commonly connected to connect each common connection point to each output terminal of the anode electrode driver 30 and control each digit. The electrode 42 is controlled by the control electrode driver 31.
The control electrode driver 31 selects a digit to be displayed, and the display contents of the selected digit are controlled by the anode electrode driver 30. A driver (control electrode driver 31) and a driver for in-display control (anode electrode driver 30) are required. Therefore, if the number of displayed digits changes, it is necessary to separately prepare a driver for digit selection having a bit number corresponding to this.

Further, in the static drive system, as shown in FIG. 9, each control electrode 42 is commonly connected and grounded, and anode electrode drivers 30 _-1 to 30 _-4 are provided for each digit. and performs display only a control to by connexion anode driver ₃₀ -1 _{to 30 -4.} Therefore, if the number of displayed digits changes, it is necessary to prepare an anode electrode driver having a bit number corresponding to this. The eighth
In FIG. 9 and FIG. 9, 43 is a cathode, 44 is a cathode heating power source, and 45 is a resistor for applying a cutoff bias voltage. _Moreover, e b, e _c each anode voltage, E _k the control electrode voltage shows a Katsuhito off bias.

The duplex drive system is a system in which the dynamic drive system and the static drive system are mixed to make a digit into one static drive unit, and this static drive unit is selected in a time division manner to drive a large number of digits. is there.
Therefore, if the number of displayed digits changes, the number of anode electrode drivers and the number of control electrode drivers must be changed accordingly.

That is, in the conventional driving device, it is necessary to prepare a dedicated driver section for each of the number of display digits and the number of anode electrodes.

When changing the number of displayed digits in this way, it is necessary to prepare different types of drivers for different systems, which is not preferable from the viewpoint of common circuits. Further, the dynamic drive system and the duplex drive system require two types of drivers, that is, an anode electrode driver and a control electrode driver, and it has been strongly desired to develop a drive circuit that can combine them.

[Object of the Invention]

In view of the above circumstances, the present invention has the same type regardless of the arrangement pattern of the lead wires with respect to the anode electrode and the control electrode of the fluorescent display tube and the number of the lead wires, and without particularly distinguishing the anode electrode and the control electrode. An object of the present invention is to provide a driving device for a fluorescent display tube which can drive the fluorescent display tube by any of dynamic drive, static drive and duplex drive by means of a driver, thereby making the circuit common. I am trying.

[Structure of Invention]

In order to achieve this object, the driving apparatus for a fluorescent display tube according to the present invention accelerates and controls the electrons emitted from the cathode by a control electrode and selectively causes the electrons to collide with the anode to which an anode voltage is applied to cause fluorescence. In a driving device for a fluorescent display tube that excites and emits light from a body layer to obtain a display, display data having data generating means for converting an input signal to be displayed into serial data according to a lead wire arrangement order for the control electrode and the anode electrode. A generation unit, a temporary storage circuit unit that stores the serial data generated by the display data generation unit and converts the serial data into parallel data, and a unique latch circuit unit that latches the parallel data accumulated in the temporary storage circuit unit. The parallel data output from the latch circuit unit is converted into a control electrode voltage and an anode voltage and applied to each electrode of the fluorescent display tube through a lead wire. And a driver part.

[Action]

The fluorescent display tube drive device according to the present invention has the above-mentioned configuration, and pays attention to the fact that the control electrode voltage and the anode electrode voltage that must be applied to the fluorescent display tube are the same. The input signals to be displayed are rearranged into serial data of the array pattern and the number of bits according to the array pattern of the terminals and the anode electrode terminals, serial / parallel converted in the temporary storage circuit section and held, and based on the holding result. The driver unit drives the fluorescent display tube so that even if the arrangement pattern of the control electrode terminals and the anode electrode terminals of the fluorescent display tube changes, only the program of the CPU constituting the data generating section is changed, and the serial data format is changed. Are matched with the arrangement pattern of the control electrode terminals and the anode electrode terminals of the fluorescent display tube.

〔Example〕

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

FIG. 1 is a functional block diagram showing an embodiment of a driving device according to the present invention. In this figure, reference numeral 6 is a reference clock generating means in which the crystal unit is an LC oscillator or the like,
The reference clock signal CLK (see FIG. 5A) generated by the reference clock generating means 6 is supplied to the CPU (central processing unit) 1. The CPU 1 is composed of a microprocessor and a memory and processes the external data D ₁ supplied through the data input terminal 7.
The following four means, that is, data generating means 2 and S
HR (Shift Register) clock generation means 3, display enable signal generation means 4, strobe signal generation means 5
Have

First, the data generating means 2 outputs the reference clock signal C
It operates based on LK and rearranges the external data D ₁ supplied through the data input terminal 7 into data (serial data D ₂ ) according to the lead wire arrangement pattern of the display tube 12 and the number of lead wires. is there. That consists of four digits of the date character display type fluorescent display tube 21 display tube 12 is by connexion controlled CPU1 has a lead wire ₁₂ -1 _{to 12 -11} 11 present as in this embodiment, and the fluorescent display Tube 2
Each respective lead wires ₁₂ -11 _{to 12 -1} 1 as shown in Figure 2 the first digit of the control electrode terminals _G 1 to 4 digit control electrode terminals _{G 4,} and the anode terminal a~ anode terminals g If so, the data generating means 2 rearranges the external data D ₁ into the format serial data D ₂ as shown in FIG. Further, when the fluorescent display tube 21 in the display tube 12 controlled by the CPU 1 has an array pattern of control electrode terminals and anode electrode terminals different from that of the fluorescent display tube 21, the data generating means 2 is used. Generates serial data D ₂ of the format that matches the arrangement pattern of the control electrode terminal and the anode electrode terminal.

When the generation of this serial data D ₂ is completed,
The data generating means 2 generates a data transfer start signal S ₀ as shown in FIG. 5C and supplies it to the SHR clock generating means 3 and, as shown in FIG. When the transfer of the data D ₂ is started and supplied from the right one bit at a time to the data input terminal 8b of the shift register section 8 and then the final bit data of the serial data D ₂ is output, As shown in (e), a data transfer end signal S ₁ indicating that the serial data D ₂ has been transferred is generated and supplied to the display enable signal generating means 4.

When the SHR clock generation means 3 is supplied with the data transfer start signal S ₀ , as shown in FIG. 5D, the clock signal C is generated by the number of bits of the serial data D _2.
Generates LKA, supplies this clock signal CLKa at the timing as the clock signal CLKa rises at the center of the serial data D ₂ bits to the clock terminal 8a of the shift register 8, the said serial data D ₂ The shift register unit 8 stores and stores one bit at a time.

Further, the display enable signal generating means 4 stops the output of the enable signal EN as shown in FIG. 5F after a time T ₁ from the time when the data transfer end signal S ₁ is supplied,
After this, when the display blanking time T ₂ has elapsed, the enable signal EN is output again and supplied to the driver unit 10.
At the same time when the output of the enable signal EN is stopped, a strobe trigger S ₂ is generated as shown in FIG. 5 (g), and this strobe trigger S ₂ is supplied to the strobe signal generating means 5.

The strobe signal generating means 5 uses the strobe trigger S ₂
After a time T ₃ (T ₃ <T ₂ ) from the time when the strobe signal STB is supplied, the strobe signal STB is output as shown in FIG. 5C, and the strobe signal STB is supplied to the latch circuit section 9. . The latch circuit section 9, the shift register section 8 and the driver section 10 constitute a drive circuit 11, and are configured as follows.

First, the shift register unit 8 receives the clock signal CLKa.
The serial data D ₂ is fetched one bit at a time and converted into parallel data D ₃ by an 11-bit shift register 18.
The parallel data D ₃ is supplied to the latch circuit section 9. The latch circuit unit 9 latches the parallel data D ₃ when supplied with the strobe signal STB 11
It is configured by including a bit latch element 19, and the data (latch data D ₄ ) obtained by this latch operation is supplied to the driver section 10. The driver unit 10 takes in the latch data D ₄ when the enable signal EN is supplied, the latch data D ₄
11 AND gates 20 _-1 to 20 generate driving voltage train V _D having a bit pattern matching the bit pattern of
20 _-11 has been configured with a, each each voltage signal the control electrode terminals G ₁ ~G ₄ and the anode terminals a~g the display tube 12 constituting the driving voltage column V _D Supplied. Therefore, for example, the data generating means 3 is the fourth
By outputting the serial data D ₂ of the bit pattern shown in the figure, “2” is displayed in the third digit of the display tube 12.

That is, if the external data D ₁ has information for lighting the first digit, a voltage (eg, 6 V) indicating “1” is supplied to the grid terminal G 1 of the display tube 12, and the other control electrode terminal G 1 is supplied. ₂ the ~G ₄ voltage indicating "0" (eg, O
V) is supplied. Therefore, in this case, only the first digit of the display tube 12 displays the display information of the external data D ₁ as shown in FIG. After this, if the external data D ₁ having the information of the two-digit lighting is supplied, the display tube 12 as shown in FIG.
The first digit is turned off and the second digit is turned on as shown in FIG. If Likewise three digits external data D ₁ having the information of the eye point _lights, 4 digits eye point lamp information external data D ₁ is sequentially inputted with the following 5 (Le),
As shown in (e), the 3rd and 4th digits of the display tube 12 are sequentially turned on, whereby the display information of the external data D ₁ is displayed.

Thus, in this embodiment, attention is paid to the fact that the control electrode voltage and the anode electrode voltage that must be applied to the display tube 12 are the same, and according to the arrangement pattern of the control electrode terminals and the anode electrode terminals of the display tube 12. The external data D ₁ is rearranged into the serial data D ₂ of the format corresponding to the array pattern, serial / parallel converted by the shift register unit 8 and latched by the latch circuit unit 9, and the driver is based on the latch result. Since the display tube 12 is driven by the section 10,
Even if the lead wire arrangement pattern of the display tube 12 changes, the CPU 1
The format of the serial data D ₂ created here can be changed by changing the program of the above, and this allows the new display tube 12 to be changed without changing the hardware part of the circuit.
Can be driven. That is, the circuit can be shared.

Further, since the duty ratio of the enable signal EN output from the CPU 1 can be arbitrarily changed by the program, the duty ratio is changed to change the ratio of the display time of each digit on the display tube 12 to the blanking time. ,
The display brightness of the display tube 12 can be changed.

Further, the drive circuit 11 in the above-described embodiment is usually integrated into an IC (integrated circuit) on the glass substrate which constitutes the display tube 12.
The display tube 12 is configured so as to directly receive the clock signal CLKa, the serial data D ₂ , the strobe signal STB, and the enable signal EN. The number of terminals of the display device portion including the drive circuit 12 and the drive circuit 11 can be significantly reduced, which can facilitate the incorporation of the display device portion and reduce the weight of the display device portion. it can.

The drive voltage sequence V _D output from the driver unit 10 includes the control electrode terminals G _{1 to} G ₄ of the display tube 12 and the anode electrode terminal a.
Since ~ g are driven at the same level, it is possible to directly drive either a static type fluorescent display tube or a duplex type fluorescent display tube with the drive voltage series V _D. In this case, it goes without saying that the format of the serial data D ₂ output from the data generating means 3 is changed by changing the program to match the terminal arrangement pattern of the fluorescent display tube to be used.

Further, in the above-described embodiment, the same voltage is applied to the control electrode and the anode electrode of the display tube 12, but in the case of a fluorescent display tube in which these must be different, for example, different light emission in the same display tube. In the case of arranging the anode electrodes to which the color phosphors are attached or in the case of a fluorescent display tube of graphic display, as shown in FIG. 6, a resistor 22 is connected to the output terminal of the driver unit 10 to reduce the voltage drop. The voltage value applied to the anode electrode may be reduced by an amount corresponding to the above, and as shown in FIG.
By using the transistor 26 and the transistor 26, a voltage corresponding to the resistance ratio of the resistors 23 and 24 may be supplied to the display tube 12.

〔effect〕

As described above, the driving apparatus for a fluorescent display tube according to the present invention converts the signal to be displayed by the display data generating unit into serial data according to the lead line arrangement order of the fluorescent display tube, and the temporary storage circuit section converts the serial data. After being converted into parallel data and once stored, it is converted into a control voltage and an anode voltage by the driver unit and applied to each electrode of the fluorescent display tube. Therefore, by changing the program of the display data generating section and changing the format of the serial data created here, the fluorescent display tube can be dynamically driven by one type of latch circuit section and driver without changing the hardware part of the circuit. It can be driven by either static drive or duplex drive, which allows the circuit to be shared. Further, the brightness can be easily adjusted by changing the duty ratio of the display time and the blanking time, and the modularization of the driver unit can be easily achieved.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing an embodiment of a fluorescent display tube drive device according to the present invention, and FIG. 2 shows the relationship between the bit of the serial data D ₂ used in this embodiment and the operation of the display tube 12. 3 and FIG. 3 are diagrams showing a format example of the serial data, FIG. 4 is a diagram showing a pattern example of the serial data, and FIG. 5 is a timing chart for explaining the functional block diagram shown in FIG. FIG. 6 is a circuit diagram showing an example of a voltage shift circuit that can be used in the present invention, FIG. 7 is a circuit diagram showing another example of the voltage shift circuit that can be used in the present invention, and FIG. FIG. 9 is a circuit diagram for explaining a known dynamic drive system, and FIG. 9 is a circuit diagram for explaining a conventionally known static drive system. 1 ... Display data generating unit (CPU), 8 ... Temporary storage circuit unit (shift register unit), 9 ... Latch circuit unit, 10
...... Driver part, 12 ...... Fluorescent display tube (display part), G ₁
~G ₄ ...... grids terminal, a~g ...... anode terminal.

Claims (1)

[Claims] 1. A fluorescent display tube for obtaining a display by accelerating and controlling electrons emitted from a cathode by a control electrode and causing the electrons to selectively strike an anode to which an anode voltage is applied to excite and emit light in a phosphor layer. In the driving device, a display data generating section having a data generating means for converting an input signal to be displayed into serial data according to a lead arrangement sequence for the control electrode and the anode electrode, and a display data generating section generated by the display data generating section. A temporary storage circuit unit that stores serial data and converts it into parallel data, a unique latch circuit unit that latches the parallel data accumulated in the temporary storage circuit unit, and the parallel data output by the latch circuit unit as control electrodes. The driving of a fluorescent display tube having a configuration including a single driver unit that converts the voltage and the anode voltage and applies the same to each electrode of the fluorescent display tube through a lead wire. Moving device.