JPS6333160B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display unit, and more particularly to a display unit with a forced erasing function that allows the display of numbers and the like to be freely erased by an external command signal.

Conventionally, when erasing the numeric display using an external erasing signal in a numeric display using a light-emitting diode, etc., the display output gate is closed by the erasing signal to block passage of the display signal and the numeric display is erased. Constituent display elements (e.g. light emitting diodes)
It was blocking the current flowing to the

However, in the conventional type, the display disappears only while the erasure signal is coming, and when the erasure signal disappears, the numbers are displayed again, so the erasure signal must be continuously applied during the time when the numbers are erased. There was this inconvenience. In other words, if the erase signal is input even momentarily, the display remains blank, and the display cannot be used in a convenient manner such as displaying numbers when new data is input.

The object of the present invention is to solve the problems of the conventional type, and to provide a numeric display unit with a forced erasing function based on the concept of converting an external erasing signal into a specific code and inputting it to a data conversion circuit. Erase the display by inputting the erase signal,
It is possible to maintain the erased state until new data is input, and to display a number corresponding to the data when inputting the data, and to change the source of input data from the outside. To make it possible to erase the display of a numeric display with an extremely simple circuit.

Therefore, according to the present invention, there is provided a coder that converts an external erasure command signal into specific erasure code data, and a coder that converts either the erasure code data or external display input data into the erasure command signal. A coupler that passes the data according to the level, a flip-flop that stores the data output from the coupler in response to an external control pulse, and a flip-flop that inputs the data of the flip-flop in response to the control pulse. a data conversion circuit having a decoder that outputs a first level drive signal when the data is the display input data, and outputs a second level drive signal when the data is the erasure code data; A display device that displays corresponding data when the drive signal from the conversion circuit is at a first level, and forcibly erases the display when the drive signal is at a second level. A functional display unit is provided.

Embodiments of the present invention will be described below with reference to the drawings. As shown in the attached drawing, a numeric display unit with a forced erasure function according to an embodiment of the present invention includes a coder 1 that receives an erasure command signal BL and converts it into a specific erasure code, and a coder 1 that displays the erasure code. Input data I ₁ ,
A coupler 2 for coupling with I ₂ , I ₃ , and I ₄ , a data conversion circuit 3 for temporarily storing the erasure code or display input data output from the coupler 2 and converting it into a display output signal, and It is equipped with a numeric display 4 and the like that receives the display output signal and displays corresponding numbers. The numeric display 4 is, for example, a seven-segment one composed of light-emitting diodes, and the anodes of the light-emitting diodes of each segment are commonly connected to the positive voltage power supply +V, and the cathodes are used as drive input terminals. When a low voltage (eg, zero volts) is applied, the segment corresponding to the input terminal emits light. Data conversion circuit 3 inputs 4-bit BCD
Flip-flop 31 that temporarily stores (binary coded decimal) numerical data at the timing of the write pulse WP
-1 to 31-4, a decoder 32 that converts the BCD number stored in these flip-flops into a seven-segment display driving signal, and driving inverters 33-1 to 33- that invert and amplify the output signal of the decoder 32. 7. here,
The decoder 32 has a certain number other than 0 to 9.
A commercially available product is used that is configured so that a display drive signal is not output when a BCD number, for example (1, 1, 1, 1) is input. The coupler 2 includes AND gates 21-1 to 21-4 and an AND gate 22.
-1 to 22-4, OR gates 23-1 to 23-4, and an inverter 24, and display input data I ₁ , I ₂ ,
Either I ₃ , I ₄ or erasure code 1, 1, 1, 1 is selectively connected to the input of data conversion circuit 3. The coder 1 is a circuit that converts the erasure command signal BL into a specific erasure code. In this embodiment, a high level (for example, +V volts) is a logic "1", and a low level (for example, zero volts) is a logic "1". 0'', the coder 1 is composed only of the buffer amplifier 11.

The operation of the above-mentioned numeric display unit will be explained.
First, erase command signal BL is input to erase signal input terminal 10.
is not applied (the voltage at the input terminal 10 is zero volts), the AND gates 21-1 to 21-4 of the coupler 2 are closed, and the AND gates 22-1 to 22-4 are opened. . At this time, the display signal input terminals 20-1 to 20-4
When the BCD number display signal inputs I ₁ , I ₂ , I ₃ , I ₄ are applied, the display signal is applied to the opened AND gate 22 -
1 to 22-4 and OR gates 23-1 to 23-4 to the data input terminals of each flip-flop 31-1 to 31-4 of data conversion circuit 3. The display signal is the write pulse
By applying WP, the data is stored in each flip-flop 31-1 to 31-4, and the data is stored in the decoder 32.
is applied to The decoder 32 converts the display signal stored in each flip-flop into a display driving signal, and the display driving signal is transmitted to the driving inverter 3.
3-1 to 33-7 to the diodes of each segment of the display 4, thereby causing the display 4 to display the corresponding number.

Next, when the high-level erase command signal BL is applied to the erase signal input terminal 10, the AND gates 21-1 to 21-4 of the coupler 2 are opened, and the AND gates 22-1 to 22-4 are closed. It will be done. In this case, the output of coder 1 has the erasure code
A BCD number (1, 1, 1, 1) is generated, and this erasure code is passed through AND gates 21-1 to 21-4 and OR gates 23-1 to 23-4 to each flip-flop 31-1 of data conversion circuit 3. to 31-4 data input terminals. When a write pulse WP is applied to the write pulse input terminal 30, the erase code 1, 1, 1, 1 is stored in the flip-flops 31-1 to 31-4 and applied to the decoder 32. As described above, the decoder 32 is configured so that when a specific code 1, 1, 1, 1 is input, the display drive signal is not output (low level), and therefore the drive inverter 33-1 All of the outputs from 33-7 to 33-7 become high level, and the diodes of any segment of the display 4 do not emit light, and the display on the display is erased. That is, while the specific erasure code is stored in flip-flops 31-1 to 31-4, the display on display 4 is erased. In this case, it is sufficient that the erasure command signal BL is applied only for a short period of time during which the erasure code can be written to each flip-flop. After the display on the display 4 is erased in this way, the display remains until the display signal and write pulse WP are applied again to the display signal input terminals 20-1 to 20-4 and the write pulse input terminal 30, respectively. remains deleted.

The above-mentioned numeric display unit with a forced erasing function can be used, for example, in a numeric display device that uses multiple numeric displays, by erasing all the numeric displays all at once when the power is turned on, so that the numeric display unit does not display misalignment when the power is turned on. Can be used when configuring. Further, when it is desired to erase the numeric display in relation to other displays, the display can be erased at an appropriate timing by an external command, and then displayed again by inputting new data. Although the case of a numeric display unit has been described above, it is clear that the present invention is applicable not only to a numeric display unit but also to a display unit that displays characters, symbols, etc. other than numbers.

As explained above, according to the present invention, by inputting an instantaneous erasure command signal, it is possible to erase the display until the next new data is input, and to display it again from the time when the data is input. With,
It is possible to erase the display on the numeric display using an extremely simple circuit without changing the source of external display input data.

[Brief explanation of the drawing]

The drawing is an electrical circuit diagram of a numeric display unit with forced erasure function according to an embodiment of the present invention. 1... Coder, 10... Erasing signal input terminal, 1
1...Batsuhuaang, 2...Coupler, 20-1
~20-4...Display signal input terminal, 21-1~2
1-4...and gate, 22-1 to 22-4...
...And gate, 23-1 to 23-4...OR gate, 24...Inverter, 3...Data conversion circuit, 30...Write pulse input terminal, 31-1 to
31-4...Flip-flop, 32...Decoder, 33-1 to 33-7...Drive inverter,
4...Numeric display.

Claims (1)

[Scope of Claims] 1. A coder 1 that converts an external erasure command signal BL into certain erasure code data; and a coder 1 that converts an external erasure command signal BL into certain erasure code data, and either one of the erasure code data or external display input data I ₁ to _{I 4} . A coupler 2 that passes the erase command signal according to the level thereof, flip-flops 31-1 to 31-4 that store data output from the coupler in response to an external control pulse WP, and the control inputting data of the flip-flop in response to a pulse;
a data conversion circuit 3 having a decoder 32 that outputs a first level drive signal when the data is the display input data, and outputs a second level drive signal when the data is the erasure code data; , a display 4 that displays corresponding data when the drive signal from the data conversion circuit is at a first level, and forcibly erases the display when the drive signal is at a second level. A display unit with a forced erase function.