JPS5941633Y2 - key input device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a key power device having a detection circuit for detecting a change in a key signal.

Traditionally, key human power signals are directly introduced into arithmetic circuits to perform arithmetic processing, but recently the content of the previous key human power signal is memorized and compared with the new key human power signal to change the content. It is now necessary to perform a sequence operation using a signal indicating that the data has been changed.

For example, in the touch channel circuit of a TV or the preset input circuit of a car radio, the previous key input signal, that is, which channel or preset button was pressed, is memorized, and at the same time, a new key input signal is input to the previous key input signal, that is, the memory contents. If this is different, it is necessary to generate a sequence control signal and process the new key input signal.

In consideration of the above points, the present invention provides a key manpower device that stores key manpower signals and generates a signal indicating that the new key manpower signal is different from the previous key manpower signal.

FIG. 1 is a circuit diagram showing an embodiment of the present invention. Keys 1 to 7 are suppression type switches in FIG. 1.

It may also be configured with a touch switch.

F1 to F7 are set-priority flip-flops, and when any key signal is generated, the output of the OR gate OR1 supplies a signal to the reset terminal RE of all flip-flops F1 to F7. A key signal is introduced into the set terminal S of the flip-flop and is set based on set priority.

That is, one of the flip-flops F1 to F7 is set by suppressing the key from 1 to 7.

EN is an encoder that encodes the output of the flip-flops F1 to FT into three lines 11, 12゜13# and outputs it.For example, when the flip-flop F2 is set, an output is generated on the line 12. .

The circles at the intersections indicate OR gates that generate logical OR outputs on the same line.

El, B2. B3 is an exclusive or gate, and the output of latches L1, L2, L3 and line /1°12.13
When there is either signal, an output is supplied to a delay type flip-flop (referred to as a D-type flip-flop) via an OR gate OR2.

CP is a clock pulse signal.

Before explaining the operation using the operation waveform diagram in FIG. Assume that both L3s are in a reset state.

When 1 is pressed on the key, only the flip-flop F1 is set, and an output is generated only on the line 11 via the encoder BN.

At that time, in the exclusive OR E1, there is no output from the latch L1 (see FIG. 2 L1), and since there is a signal on the line 11, an output is generated, and the output 02 of the OR gate OR2 is supplied to the D-type flip-flop D.

The D-type flip-flop D operates in synchronization with the clock pulse CP (see the second diagram), the latches Ll, L2 . L3
The signal on line 11 is written to latch L1.

When the data is written to latch L1, L1 in FIG.
The output 02 of the D-type flip-flop D disappears, and the output of the D-type flip-flop D disappears at the time of the next clock pulse CP.

The above example uses latches L1, L2 . When L3 is in the reset state and 1 is pressed on the key, the encoded signal will be sent to line 1.
1 and is consequently written to latch L1, but if you press any other key, a similarly coded signal will be written to latch L1.
1, L2, and L3, and at that time, D
The output of type flip-flop D is generated.

However, when the same key is pressed continuously, the flip-flops F1 to F7 do not change and the latches Ll, L2, L3
Since the content of the signal and the signal content of the line 11°12.13 are the same, the exclusive OR E1. E2. There is no output from E3.

In other words, the output of the D-type flip-flop D is generated only when a key operation different from the previous one is performed.

Therefore, the D type flip-flop D is
It may be a sequence control signal for a circuit (not shown).

Latch L1 in the above example. L2. L3 is composed of a D-type flip-flop, and by synchronizing with the clock pulse CP, the above-mentioned D-type flip-flop D may be omitted.

In the above example, the key signal is encoded.

If there is no need to encode, flip-flop F1
~F7 and encoder EN are not required, and the key signal is directly supplied to exclusive OR gl, E2゜E3,
If the output of the AND of the output of OR gate OR1 and the output of OR gate OR2 is input to a D-type flip-flop, then when there is no key signal, exclusive OR E1. E2.
Even if there is an output from E3, it is not transmitted to the D-type flip-flop D, so it operates in the same manner as above.

In the above example, before operation, the flip-flops F1 to F7 and the latches L1, L2. It is assumed that L3 has been reset, but when resetting, it is sufficient to supply the signal of the OR gate OR1 to the flip-flops F1 to F7, and the latch L
1. L2. At L3, a direct reset terminal (not shown) #
Resetting can be performed by giving a set signal, but the above reset operation is not necessary in cases where one dial is always selected, such as a TV schedule selection, but The above reset operation becomes effective when not only preset tuning but also automatic tuning is performed.

As described above, the present invention has the output of a memory circuit that introduces a key human input signal and stores its content, and a circuit that detects when the content of a new key human input signal differs, and has a simple configuration. It can detect that a key has been operated and generate signals for various controls.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is an operational waveform diagram of FIG. 1. F1 to F7 are flip-flops, EN is an encoder, E
l, E2. E3 is exclusive or. Ll, L2. L3 is a latch.

Claims (1)

[Scope of utility model registration request] A plurality of memory circuits that introduce key human input signals and store their contents, and a detection that compares the contents of the memory circuits with the contents of a new key human input signal that corresponds to each other, and outputs a write signal when the two differ. What is claimed is: 1. A key-powered device comprising: a circuit; and a key signal is stored in a storage circuit using a write signal.