JPH04175812A - Keyboard - Google Patents

Abstract

PURPOSE:To prevent malfunction due to erroneous input from occurring by nullifying a key switch group unnecessary for an operation by a validity/ invalidity discrimination part. CONSTITUTION:'1' is set on switches 8-10 in an open state, and '0' in a closed state. The output of gates 4-6 are connected to a keyboard control part 7, and the keyboard control part 7 performs communication with a device. Ordinarily, the switches 8-10 are opened, therefore, information can be transmitted to the device from key switches 1-3 even when any key switch is depressed, however, when an unnecessary key switch group exists, a correspondent switch is closed corresponding to the working status of the device, and no information is transmitted to the device even when the key switch is depressed erroneously. Since the key switch group unnecessary for the operation can be nullified, the malfunction of the device against the intention of an operator due to the depression of the unnecessary key switch is prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a keyboard, and more particularly to a method of controlling a group of keyswitches.

[Conventional technology]

Conventionally, as shown in FIG. 2, a keyboard has had one key switch group and one keyboard control section, and has a structure in which the press of a key switch is directly transmitted to the device.

[Problem to be solved by the invention]

The conventional keyboard described above has a structure that directly transmits the press of a key switch to the device, so if an unnecessary key switch is pressed during operation, the device may malfunction and operate contrary to the operator's intention. There is a drawback.

[Means to solve the problem]

The keyboard of the present invention includes a plurality of key switch groups, a discriminator that determines whether each key switch group is valid or invalid, and a gate that receives as input the output of the key switch group and the output of the valid/invalid discriminator. There is.

〔Example〕

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

FIG. 1 is a block diagram showing one embodiment of the present invention.

The key switch group 1, 2.3 is connected to one terminal of the gate 1, 2.3. Further, the other terminals of the gates 1 and 2.3 are connected to switches 1. ．． 2.3 is connected. switch 1
, 2.3 are set to "1" when the oven is open, and "0" when the oven is closed. The outputs of game) 1, 2 and 3 are connected to a keyboard control section, and the keyboard control section communicates with the device.

Normally, switches i and 2.3 are set to oven, and any key switch in the key switch group that is pressed is transmitted to the device.

If there is a group of unnecessary key switches depending on the usage status of the device, the corresponding switches are closed so that even if a key switch is pressed by mistake, it will not be transmitted to the device.

FIG. 3 is a block diagram showing another embodiment of the present invention.

A decoder is provided in place of the switch in FIG.

The number of the key switch group required for operation is received from the keyboard control section, decoded by the decoder, and only unnecessary key switch groups are enabled.

This embodiment eliminates the need for a switch and becomes a decoder, which has the advantage of being inexpensive.

[Effects of the Invention] As described above, the present invention includes a discriminator that divides a key switch group into W numbers and determines whether each key switch group is valid or invalid, and an output of the key switch group.

By having a gate that inputs the output of the discriminating section and disabling a group of key switches that are unnecessary for operation, it is possible to prevent malfunction of the device contrary to the operator's intention due to unnecessary key switch pressing.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a block diagram showing a conventional keyboard, and FIG. 3 is a block diagram showing another embodiment of the present invention. Agent Patent Attorney Uchihara Otoki 1 time

Claims (1)

[Claims] It has a plurality of key switch groups, a determining unit that determines validity/invalidity of each key switch group, a gate that receives the output of the key switch group and the output of the valid/invalid determining unit, and a keyboard control unit. A keyboard characterized in that a valid/invalid discriminator disables a group of key switches unnecessary for operation to prevent malfunctions due to erroneous input.