JPS5856026A - Display device - Google Patents

Abstract

PURPOSE:To simplify constitution and to decrease the number of parts by varying the count output of a counter through its counting operation, and reading address contents, which correspond to a code, out of a memory to a display element. CONSTITUTION:A display device 37, a counter 42 which counts clock pulses and sets its count outputs to an optional code at optional time, and a display data memory 40 whose input and output operations are independent are provided. Then, the counter outputs are connected to address inputs of the memory 40, and for memory writing, the count outputs are set to an optional address code to write data in to the addresses of the memory 40. During display operation, the count outputs of the counter 42 are varied through its counting operation to scan display digit positions, and address contents which correspond to the code are read out of the memory 40 to the element 37, which turns on dynamically.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device for equipment capable of displaying characters or numbers of multiple digits.

In general, multi-digit character or number display devices have functions such as measurement, calculation 2 clock, etc.? The control of the equipment used in the equipment is performed intensively by a calculation circuit such as a microcomputer.

FIG. 1 is an example of a circuit for lighting a 7-segment display element using a commonly used microcomputer. Please explain according to the figure below and display 1i'? l
The path is display element 1. Demultiplexer 2, driver circuit 3. Address launch lr'l path 4° data latch circuit 6
The control and calculation of the display circuit and the circuits with original functions such as measurement and timekeeping are all performed by the microcomputer circuit 6.

In the above configuration, when the number of display digits is 2N, the next step is the operation element.

(1) From the microcomputer 111 path 6, the address latch circuit 4 receives data specifying the digit, and the data latch circuit 6 receives data indicating the selection method. write in the form of code,
Then, it is output to the demultiplexer 2 and the driver circuit 3.

(2) The demultiplexer 2 selects the nth digit r of the display element 1 according to the input code, and the data latch circuit 6 outputs the selection right display data to the display element 1 via the three driver circuits, and the selected digit lights up. let

(3) The microcombination coater circuit 6 controls other originally functional circuits 72, and the four parts perform calculations.

(4) The 7 dress code 2 of digit selection is changed sequentially at a fixed period, and each digit is lit 2111 times.

(6) By repeating steps (1) to (6) above, one display element is turned on.

This type of circuit has a simple circuit configuration, so it is not widely used.
However, on the other hand, during display, the microcomputer circuit 6 must scan the digits at regular intervals, and the display data must be rewritten 7 times. However, if the functional circuit 7 is to have multiple functions, the circuit configuration and program of the entire device will be complicated even if the display circuit has a simple circuit configuration. Nanai.

In order to solve the above-mentioned drawbacks of devices with inherently complex functions, the data selector 22 has 20 memories that can store all the contents of each digit to be displayed, as shown in FIG. With the count output, the address of the memory 20 is scanned through the data selector 22, and at the same time, the display data stored in the address in the memory 20 is sent to the display element 17 (
In order to output data, the display element 20 is turned on, and when writing to the memory, the address of the memory 27 is selected via the microcomputer-engineered data selector 22 and the data is written. There is a circuit that reduces the burden on the microcomputer by having a circuit configuration in which the microcomputer is involved only when rewriting the display contents. However, this configuration makes the circuit configuration complicated.

The purpose of the invention is to further simplify the circuit configuration shown in Figure 2, reduce the number of parts and reduce costs compared to the conventional circuit, and the basic configuration to achieve this purpose is a display element and a clock pulse circuit. It has a counter that can be set to any code at any time, and an independent display data memory for input and output.The count output of the counter is connected to the address input of the memory, and the count output is By setting an arbitrary address code, data is written to the address of the memory, and during display operation, the count output is changed by the counting operation of the counter, and the digit position of the display corresponds to the code. The display element is configured to dynamically light up the display element by reading out the address contents from the memory area and providing an output terminal to the display element. An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

Figure 4 shows the 7-segment display board 36 in Figure 3 which is of course dynamically illuminated! :/b This is an example of the case where the display element 37 and
A demultiplexer 38 and a driver 39, a memory 40, an oscillation circuit 41, a counter 42 with a series reset, and a microcomputer 43 for operating this link.
The operation steps during normal display operation are as follows: (1) The oscillation circuit 411 outputs the clock pulse 48.
A counter 42 with a cable center is used for counting.

(2) By inputting the counter output 46 to the multiplexer 3, depending on the code of the counter output 46,
The display digit of the display element 37 is selected by making only one of the display digit selection signals 44 active.

(3) Select the address of the code in the memory 40 and count output 46, and output the data stored in that address to the display element via the driver 39, and display on the light display element 37. Selected by digit selection signal
The displayed digit lights up.

(4) Repeat steps (1) to (3) each time the pulse 48 is output.

When rewriting the display contents (1), the preset signal 5o sets the counter 42 with precent to the preset mode, and the above (1) to (4)
) display operation is interrupted.

(2) Output as the address care address signal 49 of the memory to be rewritten from the microcomputer - (3)
The counter 42 with preset is set to the same code as the code care address signal 49 of the output 46.

(4) The display data of the changed digit is output from the microcomputer to the memory 40, and the data of the address corresponding to the address of the area address signal 49 is rewritten in the memory write signal 52.

(6) Using the preset signal 60 (/r), return the preset counter to the 42 count mode and restart the display of the digits corresponding to the set count output code as shown in Figure 2. It can be said to be very useful in practical use because it can perform the same functions more easily and reduces the number of parts such as IC and costs.

[Brief explanation of the drawing]

1 and 2 are configuration diagrams of a conventional embodiment, FIG. 3 is an external view of a 7-segment display board, and FIG. 4 is a configuration diagram of an embodiment of the present invention. 37... Display element, 38... Demultiplexer, 39... Driver, 43...
... Microcomputer, 63 ... Original functional circuit, 46 ... Display data drive signal, 49
... Address signal, 61 ... Data signal, 40 ... Memory, 41 ... Oscillation circuit, 46 ... Counter output, 47. ...
...Memory output, 48...Clock pulse,
62...Memory write signal, 60...
...Preset signal. Name of agent: Patent attorney Toshio Nakao and one other person JR
I figure 92 figure 3 figure protection

Claims (1)

[Claims] It has a display element, a counter that counts clock pulses and whose count output can be set to any code at any time, and an independent display data memory for input and output, and the count output of the counter is connected to the address input of the memory. However, when writing to the memory, the count output is set to an arbitrary address code.The data is written to the address of the memory, and during the display operation, the count output is changed by the counting operation of the counter, and the digit position of the display is scanned. At the same time, the display device is characterized in that the address contents corresponding to the code are read from the memory area and outputted to the display element, thereby causing the display element to turn on.