JPH0421019A - Key detecting method - Google Patents

Abstract

PURPOSE:To prevent the generation of a noise in a cordless telephone set, etc., in the course of speech by selecting successively a switch group from the direction being different from the read-out direction and detecting the output information, when the read-out output information is different from the output information at an initial time. CONSTITUTION:Output information of a switch group is read out of the direction of one of the direction and the column direction of the switch group, and in the case the read-out output information is different from output information at an initial time, the switch group is selected successively from the direction being different from the read-out direction and this output information is read out. For instance, in the case the output information of the switch group in the direction, that is, input data from input ports a1 - a4 are read out and all of them are not [H] level data, the switch group in the column direction, that is, output ports b1 - b5 are selected successively and the output information of the switch group in the row direction is read out and detected. In such a way, since the key detection is executed only at the time when keys 2, 3 are depressed, a noise in the course of speech of a telephone set caused by a selecting operation of the switch group can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a key detection method for detecting an operated key.

[Prior Art] As shown in the timing chart of FIG. 4, the conventional key detection method of this type sequentially detects "L" in the column direction bl to b5, for example, at a constant timing regardless of whether a key is pressed or not.
” level output, and output information of the pressed keys is obtained from the row direction.

[Problems to be Solved by the Invention] The conventional key detection method described above always sequentially detects "H" or "L" in the column direction at a constant timing regardless of the key press.
” is output to detect the pressed key. Therefore, if such key scanning is performed constantly on a cordless phone during a call, for example, this will come as noise and interfere with the call. There was a problem. In order to remove such noise, it is necessary to add a shield plate or the like to the telephone, which poses a problem of increasing costs.

[Means for Solving the Problems] In order to solve such problems, a key detection method according to the present invention reads out output information of a switch group from either the row direction or the column direction of the switch group. , when this read output information differs from the initial output information, the operation is performed by sequentially selecting switch groups from a direction different from the read direction and reading out the output information of the selected switch groups from the read direction. This method detects the key.

[Operation] If the read output information is different from the initial output information, the switch group is sequentially selected from a direction different from the read direction, and this output information is read out.

[Example] Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a cordless telephone to which a key detection method according to the present invention is applied.

In the figure, 1 is a CPU that performs key detection and controls the entire telephone; 2 is a dial key made up of a matrix of switches; 3 is a function key made of a matrix of switches; 4 is an antenna, 5 is a wireless transmitter/receiver unit with a built-in communication circuit, T is a transmitter, R is a receiver, al to a4 are CPU input ports for detecting key presses, and b8 to b are key selections. This is the output port of the CPUI.

Next, the CP of the cordless telephone configured as above
The operation of the UI key detection method will be explained based on the flowchart shown in FIG.

First, when the power is turned on, the CPU performs an "L" level output process to all output ports b1 to b during initial processing, and sets these output ports b to b to "L".
Set to level state. This means that no matter which key among dial key 2 and function key 3 is pressed, input port a is pressed.

This is to enable detection of this pressed key via ports a4, and if no key is pressed at the initial time, all data input from input ports a1 to a4 will be rH, level data. ing. Thereafter, the following processes are executed at a constant timing.

That is, in step 10, the key data from the input ports al to a4, that is, the data of the pressed dial key 2 and function key 3, is input, and in step 11, it is determined whether all input data is "H" level data. , and if all the input data is "H" level data, the switches for each key are not closed, and therefore, none of the keys are pressed, so the process ends and the next timing arrives. When this happens, the process starts again from step 10.

In addition, if the input data is not all rH, level data, when any key is pressed and the switch is closed, one of the data corresponding to input ports a0 to a4 becomes "L". In this case, in order to detect which key the pressed key corresponds to, conventional key detection processing, which will be described later, is executed to determine which key the pressed key corresponds to. The corresponding key is detected (step 12). After this conventional key detection process is completed, in step 13 the output port b1 is
~Execute the process of giving “L” level output to b5,
This output port b0-b.

``rl'' level.

Next, FIG. 3 is a flowchart illustrating the above-mentioned conventional key detection process, that is, key scanning operation.

First, in step 20, the number of output votes (5 in this embodiment) is set in register X of this CPUI, and then in step 21, "1" is set in register y. Then, in step 22, output port by (at first, register y is set to 1, so output port b1 is selected)
Outputs "L" level to , sets other output ports to rH, level state, selects a key, and inputs the data of the selected key via input ports a, ~a4 in step 23. do.

Then, in step 24, it is determined whether all the input data is at the "H" level. If all of the input data is rH, level data, the process moves to step 26, but if all the input data is rH,
If it is not level data, it will be "N" and step 2
5, key press processing, that is, the value of the selected column direction output boat (value of register y) and each row direction input boat a
Which boat's data is "L" among the input data of 1 to a4?
” level, and detects the pressed key.

Thereafter, the process moves to step 26 to determine whether the value of register Only the output port by indicated by the value of the register y of the lever is set to the "L" level, and the next key detection is performed.

In this way, when key detection is performed by sequentially selecting output ports b1 to b, the value of register y becomes 5, and since the value of register X is also set to 5, step 26 is performed. The result is "Y" and this key detection process ends.

As explained above, this key detection method does not perform constant key scanning, but first sets ports b4 to b to the "L" level state, and then inputs data from input ports a1 to a4. It is determined whether or not any key has been pressed, and key scanning is performed only after any key is pressed.

In this embodiment, when the output information of the switch group in the row direction, that is, the input data from the input ports a1 to a4, is not all "H" level data, the output information of the switch group in the column direction, that is, the output Boat b□～
b, is sequentially selected and the output information of the switch group in the row direction is read out for detection, but conversely, when the output information of the switch group in the column direction is read out and it is not at rH, level, the output information of the row direction switch group is read out and detected. The switch groups may be sequentially selected to detect the output information of the switch groups in the column direction.

[Effects of the Invention] As is clear from the above explanation, in the key detection method according to the present invention, when the readout output information differs from the initial output information, the key detection method sequentially starts from a direction different from the readout direction. Since the configuration is configured to select a switch group and detect this output information, and key detection is performed only when a key is pressed, it is possible to eliminate noise during telephone calls caused by the selection operation of the switch group. Therefore, there is an effect that the telephone can be constructed economically.

[Brief explanation of the drawing]

Fig. 1 shows the key detection method according to the present invention? A block diagram showing an example of the applied cordless telephone, FIG. 2 is a flowchart explaining this operation, FIG. 3 is a flowchart explaining the operation of conventional key detection, and FIG. 4 is a timing chart of conventional key detection. It is. 1-...CPU, 2...Dial key 3...
Function key, 4...Antenna, 5...-Radio transmitting/receiving section, T...Telephone, R-...Telephone receiver, a1 to a4
...Input port, b engineering ~ b5 ・Output port.

Claims (1)

[Scope of Claims] A device comprising a plurality of switch groups arranged in a matrix of M rows and N columns and provided corresponding to a plurality of keys, wherein either the row direction or the column direction of the switch group The output information of the switch group is read from one direction, and when the read output information differs from the initial output information, the switch group is selected by sequentially selecting the switch groups from the direction different from the read direction. A key detection method characterized in that an operation key is detected by reading out output information from the reading direction.