JPH0560593B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to improvements in dot matrix light emitting display devices. BACKGROUND ART A conventional dot matrix light emitting display device (hereinafter referred to as a matrix display device) of this type has light emitting elements (not shown) such as light emitting diodes arranged in a dot matrix shape, as shown in FIG. A dot matrix light-emitting display 1', and a driving device 2' for selectively driving and driving the light-emitting elements of the matrix light-emitting display 1' to obtain an arbitrary lighting display pattern are constructed as one set. It is comprised of a plurality of display units 3', and data processing necessary for lighting the display is performed using a control device (hereinafter referred to as CPU) composed of a computer or the like. In such a dot matrix light emitting display device a, the driving device 2' includes a shift register 21' that temporarily stores pattern display data, and a parallel transfer of the pattern display data stored in this shift register 21'. A latch circuit group 22' temporarily stores the data, and one matrix axis corresponding to the light-emitting portion of the dot matrix light-emitting display 1' to be lit and displayed according to the pattern display data from the latch circuit group 22'. A first driver circuit 23' having a selectively designated driving element (not shown) receives a scanning signal for sequentially scanning the other matrix axis of the dot matrix light emitting display 1', and emits this scanning signal. Display body 1'
A line decoder 24' which converts into a scanning signal according to other matrix axes is driven in response to a scanning signal from the line decoder 24', and, together with a first driver circuit 23', selectively selects a light emitter element to be lit. The second driver circuit 2 is energized and lights up.
5'. However, in such a display device a,
The line decoder 24' is configured to input a multi-bit signal sent by the CPU and convert it into a scanning signal corresponding to the matrix axis of the matrix display 1'. The number of input lines has increased, and the wiring structure has become more complex. For example, in the 16x16 LED dot matrix light emitting display device shown in Fig. 4, the line decoder 2
Since a 4-bit scanning signal is sent from the CPU to line 4', the number of lines corresponding to the input lines of the line decoder 24 is necessarily required, which increases the number of wires. In addition, the number of signal lines connecting display units to transmit signals to the next display unit 3 increases, and a waveform shaping circuit (which changes the waveform of the pulse signal to be transmitted) installed at the input/output end of the signal line also increases. The number of devices (provided for shaping the edges) increases accordingly, making the overall structure expensive and complex. Problems to be Solved by the Invention The purpose of the present invention is to solve the above-mentioned problems, and to improve the wiring structure by reducing the number of signal input lines from the outside and the signal lines between display units. It is an object of the present invention to provide a dot matrix light emitting display device which can be simplified, is inexpensive, and has a simple structure. Means for Solving the Problems The above object is to provide a dot matrix light emitting display in which light emitting elements such as light emitting diodes are arranged in a dot matrix, and a drive for selectively lighting and driving the light emitting elements of the display. In a dot matrix light emitting display device comprising a plurality of display units configured as a set, each of the driving devices is connected to a shift register for temporarily storing pattern display data, and a shift register for temporarily storing pattern display data; The device has a latch circuit group that transfers pattern display data in parallel and temporarily stores it, and a drive element that specifies one matrix axis of the dot matrix light-emitting display according to the pattern display data from the latch circuit group. a first driver circuit;
an n-bit counter that is incremented in response to a latch pulse sent to the latch circuit group; a line decoder that converts the n-bit output of this counter into a scanning signal that sequentially scans the other matrix axis of the dot matrix light emitting display; It is configured in combination with a second driver circuit that is driven in response to a scanning signal from the line decoder and cooperates with the first driver circuit to selectively energize and light up the light emitting elements to be lit. This is achieved by a dot matrix light emitting display device characterized by: Embodiment of the Invention An embodiment of the invention will be described below with reference to the accompanying drawings. FIG. 1 is an example diagram showing the configuration of the present invention. In the figure, 1 is a 16×16 dot matrix light emitting display, and 2 is a drive device for lighting and driving the dot matrix light emitting display 1. A display unit 3 includes a light emitting display body 1 and a driving device 2 as a set. Although only one display unit 3 is shown in the figure, a dot matrix light emitting display device A is constructed by combining a plurality of such display units 3. Each of the drive devices 2 provided in each display unit 3 receives pattern display data (DATA signal) sent in time series from the CPU through the DATA terminal, and clock pulses sent from the CPU through the CLK terminal in the same way. a shift register 21 that shifts and accumulates by (CLK signal);
A latch circuit group 22 that simultaneously transfers the pattern display data stored in the shift register 21 in parallel using a latch pulse (LATCH signal) sent from the CPU through the LATCH terminal and stores it temporarily; A driving element (not shown, for example, a switching transistor or the like is adopted) that selectively specifies one matrix axis corresponding to the light-emitting portion of the dot matrix light-emitting display 1 to be lit and displayed according to each output of the dot matrix light-emitting display 1. A first driver circuit 23 is provided, and the pattern display data is a 16-bit signal that specifies which of the Y-axis of the matrix axes, that is, Y1 to Y16, should be energized. . On the other hand, the latch pulse is also sent to the n-bit counter 26, and this counter 2
The output of 6 is further input to a line decoder 24. The counter 26 is incremented every time a latch pulse is input and outputs an n-bit signal, and the n-bit signal thus output is further transferred to another matrix axis by the line decoder 24. It is converted into a scanning signal that sequentially scans the X axis, that is, X1 to X16. In addition, the counter 26
The latch pulse is input 16 times, and each time the X-axis scan completes, that is, each time the 16 types of pattern display data that make up one word are sent (this reset pulse is also sent at the start of control). to
Although a reset pulse (RES signal) is sent from the CPU through the RES terminal, such a reset operation is not an essential requirement of the present invention and is
When the first pattern display data for one word is output from the driver circuit 23, scanning to the X axis starts from the This is done to correct a malfunction when it occurs. In the case of the embodiment, the counter 26 is a 4-bit hexadecimal counter, and the 4 bits from this counter 26 are
The bit output is further converted by a line decoder 24 into a scanning signal for scanning other matrix axes X1 to X16. Here, the line decoder 24 has a configuration as shown in FIG. 3, and each output of the counter 26 is connected to 16 AND gates.
The configuration is such that it can be inputted to AND1 to AND16 and sequentially converted into an X-axis scanning signal according to the output of the counter 26. Table 1 shows the relationship among the outputs (scanning signals) of the latch pulse, counter 26, and line decoder 24.

【table】

[Table] Reference numeral 25 denotes a second driver circuit having the same configuration as the first driver circuit 23, which is driven by the scanning signal output from the line decoder 24 and cooperates with the first driver circuit 23. Then, any light emitting element of the dot matrix light emitting display 1 is selectively energized and lit. FIG. 2 is a time chart illustrating an example of the operation of the dot matrix light emitting display device A of the present invention. A multi-bit signal a serving as pattern display data generated by a CPU (not shown) or the like is sequentially sent to the shift register 21 by a clock pulse b and is stored therein. Then, each time the latch pulse d is sent, the pattern display data accumulated in the shift register 21 (in the illustrated example, it is a 16-bit signal specifying the Y axis to be energized) is temporarily sent to the latch circuit group 22. The first driver circuit 23 is driven by the stored data, and the Y-axis is designated in accordance with the light emitting element to be lit. At the same time, the latch pulse d is applied to the counter 26.
The counter 26 also increments the value. The output of this counter 26 becomes a 4-bit signal and is sent to the line decoder 24.
Then, the output signal drives the second driver circuit 25 to output a scanning signal f for sequentially scanning the X-axis. In addition, the counter 26 receives 16 latch pulses b.
It is reset by the reset signal c every time the counter 26 is sent, and the output of the counter 26 becomes "1, 1, 1, 1", and the first driver circuit 23 resets the pattern display data to 1. When the first word of a word, that is, the pattern display data corresponding to the X1 axis, is output, the synchronization is such that scanning starts from the X1 axis with the next latch pulse sent from the CPU, which prevents malfunctions due to noise. This allows for corrections if they occur. Although the operation of one display unit has been described above, similar operations are performed for other display units as well. In the above embodiment, an example was shown in which the present invention was applied to a 16X16 dot matrix light emitting display, but it goes without saying that it can be applied to other dot matrix light emitting displays such as an 8X8 dot matrix light emitting display. In that case, it goes without saying that the shift register, counter, latch circuit group, and other components may be modified as appropriate. Furthermore, the lighting control operation of the dot matrix light emitting display should not be limited to the above-mentioned one.
It goes without saying that various other methods can be used. Effects of the Invention Since the present invention has the above configuration, the number of signal input lines from the outside can be reduced, the number of signal lines required to connect each display unit can also be reduced, and the structure of the device can be simplified. There are advantages. Furthermore, the number of waveform shaping circuits provided at the input and output terminals of the signal lines can be reduced, and a dot matrix light emitting display device that is inexpensive and has a simple structure can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an embodiment of the device of the present invention, and FIG.
FIG. 3 is a time chart for explaining its operation, FIG. 3 is a block diagram of an embodiment of a line decoder, and FIG. 4 is a block diagram of a conventional dot matrix light emitting display device. (Explanation of symbols), A... Dot matrix light emitting display device, 1... Dot matrix light emitting display body,
2...Drive device, 21...Shift register, 22
... Latch circuit group, 23 ... First driver circuit, 24 ... Line decoder, 25 ... Second driver circuit, 26 ... Counter, 3 ... Display unit.

Claims (1)

[Scope of Claims] 1. One set of a dot matrix light emitting display in which light emitting elements such as light emitting diodes are arranged in a dot matrix, and a driving device for selectively driving and lighting the light emitting elements of the display. In a dot matrix light emitting display device comprising a plurality of display units configured as a A group of latch circuits that perform parallel transfer and temporarily store information,
A first driver circuit has a driving element that specifies one matrix axis of the dot matrix light-emitting display according to pattern display data from the latch circuit group, and a latch pulse sent to the latch circuit group is used to drive the dot matrix. a line decoder that converts the n-bit output of this counter into a scanning signal for sequentially scanning the other matrix axis of the dot matrix light emitting display; , a dot matrix light emitting display device comprising: a second driver circuit which cooperates with the first driver circuit to selectively energize and light the light emitting elements to be lit;