KR950012933B1 - Key and led controller in key system and control method thereof - Google Patents

Abstract

an LED matrix having an LED in a cross point of a plurality of row and columns; a key matrix having keys in a cross point of the rows shared with the LED matrix and the columns outputting a key input signal; a plurality of row ports connected to the rows, for outputting a key scan signal; a plurality of column ports connected commonly to a driving element matrix and the key matrix, for outputting an LED driving signal or for receiving the key input signal; a microprocessor having a selection signal output port which outputs a selection signal in turn having a first state and a second state each designating the output/input of the column ports; and a direction control buffer for selectively connecting the columns of the LED matrix or the columns of the key matrix to the output port of the microprocessor, in correspondence with the selection signal, wherein the direction control buffer outputs the LED driving signal in one-to-one manner in the first state of the selection signal and receives the key input signal in one-to-two manner in the second state of the selection signal, such that the period of the key input signal is shorter than that of the LED driving signal.

Description

Control device for keys and light emitting elements of key system and method

1 is a schematic block diagram of a conventional key and LED control device.

2 is a preferred embodiment of a key and LED control device according to the invention.

The present invention relates to an apparatus and method for controlling a key and a light emitting element in a key system using a one-chip microcomputer.

In general, in a system that transmits voice and data in both directions by using a key system, a control signal is generated by pressing a key, and the control state of the key system is displayed by using a light emitting element such as an LED (Light Emitting Diode). do.

In the conventional key system, when the key and the LED are controlled, the one-chip computer and the column or row of the LED or the LED have been connected and used, so that the quantity of the key and the LED is restricted. There was a difficult problem such as the need to change the control circuit and program in accordance with the increase and decrease of the LED usage quantity.

Techniques for eliminating this problem are disclosed in detail in Korean Patent Application Publication No. 89-3752 filed by the applicant and published October 4, 1989.

Among the methods of controlling the LED and the key of the key system, there is a dynamic control method. FIG. 1 is a block diagram showing the configuration.

The LED matrix 20 and the key matrix 30 are respectively configured to control keys and LEDs, and the eight ports P10 to P17 of the microprocessor 10 are always used as output terminals of the scan signal. It is connected to each matrix in a common row method.

The other eight ports P20 to P27 of the microprocessor are used as output terminals when the LED is controlled and connected to the LED matrix row 20, and are used as input terminals when key input is connected to the key matrix row 30. The remaining port P0 of the microprocessor 10 controls the input and output states of the direction control buffer 40.

First, let's look at the key control method.

To check the key input, select one of the eight common lines to make 'L' state, and output the rest to 'H' state and read the column state through P20 ~ P27. To do this, first, P0 is outputted as 'H' in order to make P20 to 27 into the input mode, thereby switching the direction control buffer 40 to the input mode. For about 20μsec of 2ms period, one row of 8 common rows is selected to read the key column corresponding to the row, and the next row is selected the next row to read the key string 8 times. The key scan interval in which the first row is selected again after the first row is selected is 16 msec, and a key scan time of at least 18 msec and up to 32 msec is required by setting the key scan counter to 2 to prevent a malfunction of the key operation.

Next, look at the LED control method. The LED control section is composed of eight rows P10 to P17 and eight columns which are commonly used for keys. Select one of the 8 rows to make 'L' and output the rest to 'H'. At this time, if you write the output of the column, LED can be emitted. Similarly, it outputs about 2msec 'L' every 16msec, so you get a visual effect that looks like the LED is on. In practice, however, since 20 μs is used for key scanning, only 2 ms-20 μsec = 1980 μsec, or 1.98 msec, is turned on.

However, the key scanning device shown in FIG. 1 has the following disadvantages. That is, the time ratio (called this "LED control time ratio") that represents the visual effect that the LED appears to be on That is 0.1238.

This results in fine flickering and the disadvantage of low brightness. In addition, the frequent key scan operation at 2msec cycle increases the load on the microprocessor.

Accordingly, it is an object of the present invention to provide a key and light emitting device control apparatus and method for a key system having clear light emission by increasing the control time ratio of the light emitting device.

Another object of the present invention is to provide a control device for a key and a light emitting device of a key system which reduces the load of a microprocessor by prolonging a period of key input according to a key scan.

The present invention for achieving the above object is characterized in that the control period of the light emitting device is shorter than the period of the key scan to increase the light emitting device control time ratio.

Hereinafter, to facilitate understanding of the present invention, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, a row means a data line arranged in a row direction, and a column means a data line arranged in a column direction.

In addition, the light emitting device will be described by taking an example of a typical LED.

2 is a schematic block diagram showing a preferred embodiment according to the present invention.

The configuration of FIG. 2 will be described. The microprocessor 50 has four common row ports P10 to P13, twelve column ports P20 to P31, and a P0 port for outputting input / output selection signals. As a result, the LED matrix 60 and the key matrix 70 each have a matrix of four rows and eight columns, and the columns of the matrix are respectively provided to the column ports P20 to P31 of the microprocessor 50 through the direction control buffer 80. One to one common connection. The direction control buffer 80 transmits output signals of P20 to P31 to the LED matrix columns or key inputs output from the columns of the key matrix 70 according to the selection signal applied from the selection signal output terminal P0 of the microprocessor. It is a means to convey to -P31. The LED matrix 60 and the key matrix 70 share common rows connected to the four row ports P10 to P13 of the microprocessor 50 and have 12 columns each. The LED matrix 60 thus consists of 48 LEDs and the key matrix 70 has 48 keys.

The key and LED control method of FIG. 2 will be described.

In order to check the key input, the microprocessor 50 selects one of four common lines and outputs the 'L' state with the rest of the rows as 'H', and outputs 'H' at the P0 port to control the direction. After the buffer 80 is switched to the input mode, the key matrix columns are read through P20 to P31.

At this time, the selection signal output from the P0 port is applied as a pulse train whose period is 2 msec and the 'H' width for one period is 20 μsec. When the selection signal is 'L', the direction control buffer 80 outputs the LED driving signal to the output mode, that is, the columns of the LED matrix. It operates in input mode that accepts key input only when the first or odd numbered 'H' is collected from 'H'. Therefore, the direction control buffer 80 operates to have one input mode in two output modes. Accordingly, the period of LED driving becomes 2 msec while the period of key input becomes 4 msec longer than that. It should be noted that making the period of LED driving shorter than the period of key input is the biggest technical idea of the present invention.

Therefore, during one 20msec scan period of 4msec, one row of four common rows is selected and the key column corresponding to the row is read, and the other row is selected four times to read the key column. . The key scan interval in which the first row is selected again after the first row is selected is 16 msec, and the key scan time takes a minimum of 20 msec and a maximum 32 msec with the kisscan counter set to 2 to prevent a malfunction of the key operation.

On the other hand, if one of the four rows that are common rows is selected as 'L' and the rest are output as 'H' and at this time, if the column output is lighted through the column port, the LED can be emitted. Since the driving of LED is controlled by 2msec period according to the selection signal output from P0 port of microprocessor, it outputs 1.928msec every 8msec, so the visual effect that LED seems to be on is excellent and brightness is higher than before. Brighter

That is, the LED control time ratio As it is larger than the previous 0.1238, fine LED flicker is eliminated and brightness is greatly improved.

In this case, as the key input period becomes 4 msec, the load to be processed in the microprocessor is reduced.

Accordingly, the same effect and performance can be obtained by increasing the period of 2 msec of the conventional key scan time to 4 msec, thereby reducing the load on the microprocessor.

As described above, according to the present invention, by controlling the period of the LED control and the key control different from each other, the key system that can increase the sharpness by increasing the LED control time ratio, and reduce the load of the microprocessor is a key and LED control device Can be obtained.

Claims (2)

A light emitting element matrix 60 having light emitting elements at the intersections of a plurality of rows and columns; A key matrix 70 having a key at an intersection of rows shared with the light emitting element matrix 60 and columns for outputting a key input signal by pressing; A plurality of row ports connected to the rows for outputting a key scan signal, and a plurality of row ports for common connection to the columns of the driving element matrix 6 and the key matrix 70 to output a light emitting element driving signal or to accept a key input signal. A microprocessor (10) having a column port, and a selection signal output port for outputting a selection signal alternately having a first state and a second state specifying respectively output and input operations of the column port; A key system having a direction control buffer 80 for selectively connecting the columns of the light emitting element matrix 60 or the columns of the key matrix 70 to the column ports of the microprocessor 10 in response to the selection signal. In the key and the control device of the light emitting element; The direction control buffer; The light emitting device driving signal is output in one-to-one correspondence with the first state of the selection signal and the key input is received in correspondence with at least one-to-one in the second state. Key and light emitting device control device of the key system characterized in that the shortening. A light emitting element matrix 60 having light emitting elements at the intersections of a plurality of rows and columns; A key matrix 70 having a key at an intersection of rows shared with the light emitting element matrix 60 and columns for outputting a key input signal by pressing; A plurality of row ports connected to the rows for outputting a key scan signal, and a plurality of row ports for common connection to the columns of the driving element matrix 6 and the key matrix 70 to output a light emitting element driving signal or to accept a key input signal. A microprocessor (10) having a column port, and a selection signal output port for outputting a selection signal alternately having a first state and a second state specifying respectively output and input operations of the column port; A key system having a direction control buffer 80 for selectively connecting the columns of the light emitting element matrix 60 or the columns of the key matrix 70 to the column ports of the microprocessor 10 in response to the selection signal. A control method of a key and a light emitting element; The direction control buffer 80 connects a column of the light emitting element matrix 60 and a column port of the microprocessor 10 in a one-to-one correspondence to the first state of the selection signal output from the microprocessor 10. The driving signal is output, and the microprocessor (by receiving the key input by connecting the columns of the key matrix 70 and the column ports of the microprocessor 10 at least one-to-one corresponding to the second state of the selection signal). 10. A method of controlling a key and a light emitting device of a key system, characterized in that the control time ratio of the light emitting device is increased by making the time for outputting the light emitting device driving signal longer than the time of receiving the key input.