JPH0369480B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a remote control transmitter used in poor environmental conditions such as for consumer use.

[Conventional technology]

An example of a conventional generally known remote control transmitter is shown in FIG. 3 and will be described. In the figure, 1 is an oscillation circuit that generates a reference signal and has an oscillation stop function, 2 is a timing generation circuit that inputs the reference signal from oscillation circuit 1 and generates a timing (clock) signal, and 3 is m×n 4 is a scan output circuit that outputs a scan signal to the keyboard matrix 3, and 5 is a key input circuit that inputs the output of the keyboard matrix 3.

6 is an instruction circuit that determines the key input signal from the keyboard matrix circuit 3 and sets the output timing of the transmission signal; 7 is a first counter that sets the operating order of this instruction circuit 6; 8 is the above-mentioned This is an output circuit that receives the output signal from the instruction circuit 6 and outputs a transmission signal 70.

The operation of the conventional remote control transmitter configured as described above will be explained with reference to the time chart in FIG. 4 and the enlarged view of the keyboard matrix in FIG. 7.

FIG. 4 shows the input signal applied to the input terminal 10 of the key input circuit 5 and the scan signal applied to the output terminal 40 of the scan output circuit 4 in the keyboard matrix 3.
This is a time chart for when the key is turned on and off.

Further, FIG. 7 is an enlarged view of the keyboard matrix of FIG. 3, and this keyboard is turned on when a key is pressed and turned off when the key is released. When the key is turned on, the key scan output 40 and the key input 10 are connected.

In the figure, A is the input terminal 1 of the key input circuit 5.
0 indicates the input state, B, C, and D indicate the states of the output terminals 40, 50, and 60 of the scan output circuit 4, that is, scan output signals, and T to N indicate the count value of the counter 7, respectively. E indicates the transmission signal 70, and F indicates the oscillation state of the oscillation circuit 1.

First, in the key input standby state (period (a)) in which no key in keyboard matrix 3 is turned on,
The state of the input terminal 10 of the key input circuit 5 is "H",
Output terminals 40, 50, 60 of scan output circuit 4
The states B, C, and D of are "L", and the state E of the transmission signal 70 is "L", and the instruction circuit 6
Set the operating order. The first counter 7 is in the initial count state as shown in T to N, and the oscillation circuit 1 is in an oscillation stopped state as shown in F.

Point (α) in A is when the key in keyboard matrix 3 is turned on, and in the key input standby state in period (a), when any key is pressed, the standby state is canceled and key input is possible. (period (b)). That is, in the oscillation circuit, any one of the inputs 10 to 30 of the key input circuit is "L".
When it detects that it has become, it starts oscillating,
Oscillation is stopped when the instruction circuit determines that there is no key input and outputs a command to stop the oscillation. In the example shown in FIG. 4, the input terminal 10 of the key input circuit 5 is connected to the scan output circuit 4.
The oscillation circuit 1 starts oscillating by detecting "L" at the output terminal 40 of the scan output circuit 4.
The keyboard matrix 3 is moved in the row direction by outputting "L" signals shifted by a predetermined time from the point (α) as shown in B, C, and D of B, C, and D to the keyboard matrix 3. Scan.
For example, as shown in FIG. 8, this "L" signal has signals Q ₁ , Q ₂ , Q ₃ which are frequency-divided signals of FIG. 4 (0, 1, 1), (1, 0, 1), (0, 0,
1) It can be created by decoding what has become and outputting the decoded signal while the oscillation circuit is oscillating. In addition, the reason why signal A in Fig. 4 becomes "L" at point A after point (α) is because signal B becomes "L" at point B.
This is because this is transmitted to the input 10 of the key input circuit 5 via the keys of the keyboard matrix.

In order to prevent chattering due to key operations, the key input circuit 5 inputs the input signals at timings Q ₄ , Q ₅ , and Q ₆ that are shifted by a predetermined time from the falling edges of B, C, and D, as shown in FIG. 9, for example. input 10, 20,
By sequentially inputting 30, the keyboard matrix 3 is scanned in the column direction and input is performed.
Further, with the start of oscillation of the oscillation circuit 1, the first counter 7 starts counting as indicated by numbers T to N in FIG.

The above-mentioned tones are each output bit of the counter 7, and determine the order of operation of the instruction circuit.
For example, in the initial state, all of the tones are "L", and at the start of operation, the operation of the instruction circuit 6 is set by sequentially counting up all the signals from the "L" state. The instruction circuit 6 determines a key input and selects a transmission signal corresponding to the key input. This selection operation is performed as follows.

That is, the instruction circuit 6 receives information from the scan output circuit 4 which signals B, C, and D in FIG.
By determining at which timing of Q ₄ , Q ₅ , and Q ₆ an input was obtained, it is determined which key on the keyboard matrix 3 was pressed, and a transmission signal corresponding to that key is output to the output circuit 8. can.

This transmission signal is as shown in Fig. 10. For example, by setting the narrower pulse interval to "0" and the wider pulse interval to "1", in the case of Fig. 10, the information is "010001". Can be sent to the receiving side of the remote control signal. The receiving side decodes this signal. For example, if the receiving side is a TV receiver, it judges this remote control signal and turns the power on/off.

Next, if there is no key input (period (c)), the instruction circuit 6 determines that there is no key input according to the count value of the first counter 7, and sends scan output signals B, C, and N. becomes “L”, and the first
The count values T to N of the counter 7 are in the initial state (point (β)).

With the above-described operation, when a key of the keyboard matrix 3 is turned on, the oscillation circuit 1 operates, and when the key is turned off, the oscillation circuit 1 stops oscillating.

[Problem that the invention seeks to solve]

A conventional remote control transmitter is configured as described above, and generally has a count value of the first counter 7 that sets the operating order of the instruction circuit 6, and a count value for operating the instruction circuit 6. are not necessarily consistent.

Therefore, due to external noise, etc., the first
If the count value of the counter 7 becomes a value other than the count value used to set the operation order of the instruction circuit 6, the instruction circuit 6 becomes inoperable, and the oscillation circuit 1 There was a problem that there was a risk that the oscillation would continue.

Moreover, the key input circuit 5 and the scan output circuit 4 are
Since the keyboard matrix is configured, capacitive coupling is likely to occur, and when the oscillation is stopped, the scan output circuit 4 becomes "L", so this is transmitted to the key input circuit 5, and the oscillation circuit starts oscillating again even if there is no normal key input. There was a problem with the situation.

As an example of this state, a time chart is shown in Fig. 5 and explained. Up to period (b), the time chart is the same as in Fig. 4, but in period (c), noise etc. The case where the count value of the counter 7 becomes incorrect and becomes larger than the count value used for setting the operation order of the instruction circuit 6 is defined as point (γ). And this (γ)
After this point, the instruction circuit 6 becomes inoperable, the oscillation circuit 1 continues to oscillate, and there is a risk of becoming unable to escape from the state of period (d). In other words, there is a risk that the battery will be wasted unnecessarily and that it will become impossible to escape from the state where transmission is not possible.

Figure 6 also shows that when there is capacitive coupling between the scan output circuit and the key input circuit, even if the scan output circuit becomes "L" and attempts to stop oscillation, this "L" remains in the key input circuit. This shows the possibility that the oscillation cannot be stopped due to the application (see point ξ).

To get out of this state, you need to turn off the power and then turn it on again to perform the initial settings.

In view of the above points, the present invention has been made to solve such problems.The purpose of the present invention is to eliminate the drawbacks of the above-mentioned conventional circuits with a simple configuration, and to be able to operate even in a place with a bad environment and a lot of noise. The purpose is to provide a remote control transmitter that can be used without worrying.

[Means for solving problems]

The remote control transmitter according to the present invention includes a determination circuit that determines a change in level of an output signal of an instruction circuit, and counts clocks from a timing generation circuit, and when the determination circuit determines a change in output level. A second counter to be reset is added, and when this second counter reaches a set value, the output state of the scan output circuit is set to the initial state, and furthermore, the second counter finishes counting. At this point, the oscillation of the oscillation circuit is stopped, and the first counter for setting the operating order of the instruction circuit is set to a constant count value, that is, the first counter is set to the initial state. be.

[Effect]

In the present invention, the clock from the timing generation circuit is counted by the second counter, the level change of the output signal is detected by the determination circuit, and when a level change occurs, the second counter is reset, and the second counter is reset. When the second counter reaches the first set value, the scan output circuit is set to the initial state, and when the second counter reaches the second set value, which has a larger count than the first set value. Since the oscillation circuit is stopped and the first counter is set to the initial state, the state where transmission becomes impossible without stopping oscillation is automatically returned to the standby state.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a block diagram illustrating one embodiment of a remote control transmitter according to the present invention.

In FIG. 1, the same reference numerals as in FIG. 3 indicate corresponding parts, and 9 is an instruction circuit 6.
A determination circuit for determining a level change of an output signal of
0 is a second counter that counts the clock from the timing generation circuit 2 and is reset when the determination circuit 9 determines a change in the output level.

The determination circuit 9 detects when the instruction circuit 6 outputs an output signal to the output circuit 8, and when the determination circuit 9 detects the output, that is, when the instruction circuit 6 is operating normally, the second The counter 10 is reset, and when the second counter 10 reaches the first set value, the output of the scan output circuit 4 is set to the initial state, and the output of the scan output circuit 4 is set to the initial state when the second counter 10 reaches the first set value. The oscillation circuit 1 is configured to stop oscillating when the set value of 2 is reached, and the first counter 7 is set to an initial state.

Next, the operation of the embodiment shown in FIG. 1 will be explained using the time chart shown in FIG.

In FIG. 2, the same reference numerals as in FIGS. 4 and 5 indicate the same or equivalent parts, ``R'' indicates a reset signal to the second counter 10 of the determination circuit 9, and ``O'' indicates the second counter 10. 2 shows the output signal of the set count value of the counter 10.

First, point (α) is when the key of the keyboard matrix 3 is turned on. At this time, the input terminal 10 of the key input circuit 5 detects "L" of the output terminal 40 of the scan output circuit 4, and the oscillation circuit 1 starts oscillation, and the first counter 7 starts counting like T-NU. Then, this first counter 7
According to the order in which the count value advances, the instruction circuit 6 determines the key input, selects the transmission signal corresponding to the key input, and outputs the transmission signal 70 from the output circuit 8.

Next, the second counter 10 starts counting when the oscillation circuit 1 starts oscillating. The determination circuit 9 detects a change in the level of the transmission signal 70 and outputs a reset signal to the second counter 10. When the second counter 10 receives this reset signal, it resets the count value. Therefore, the second counter 10 is reset every time the reset signal becomes "H".

At point (γ), if the count value of the first counter 7 becomes larger than the count value used to set the operation order of the instruction circuit 6 due to noise or the like, the period (γ) shown in FIG. The situation will be the same as d). In this state, the instruction circuit 6 is inoperative, so the signal from the determination circuit 9 remains at "L". Therefore, the second counter 10 continues counting, and when the first set value is reached, the output signals R to N of the scan output circuit 4 are set to the initial state "L" (see ξ ₀ point). ). At this point, the scan output is 40-60
An "L" input is added to the key input signal A due to the capacitive coupling between the key inputs 10 and 30, but since the second counter 10 has not reached the second set value, the instruction circuit 6 remains inactive. In addition, the oscillation circuit 1 is also in the oscillation state, and even though the second counter 10 exceeds the first set value, even if "L" is transmitted to the key input signal A, this remote The control transmitter remains inactive. Then, when the second counter 10 reaches the second set value, the counter 10 stops the oscillation of the oscillation circuit 1, and sets the count value of the first counter 7 to the initial set value. The control transmitter can exit the period (d) state and return to the standby state of period (a) (see ξ ₁ point).

Note that if the first count value and the second count value are made the same, the oscillation cannot be stopped as shown in FIG. 6, so the second count value is the same as the first count value.
It must be larger than the count value of .

In this way, this embodiment can eliminate the drawback of the conventional circuit shown in FIG. 3 that it becomes unable to transmit without stopping oscillation, and can be used even in a place with a lot of noise and a bad environment. You can use it without worrying about anything.

Note that although the above embodiment uses a counter circuit, this counter circuit can be implemented using RAM,
It may be realized by a CPU program using registers or the like, and the same effect as the above embodiment can be obtained.

〔Effect of the invention〕

As described above, the remote control transmitter according to the present invention includes a determination circuit that determines the level change of the output signal of the instruction circuit, and a timing generation circuit that counts clocks, and the determination circuit that determines the output level. Add a second counter that is reset when determining a change in
When this second counter reaches the set first count value, the scan output circuit is set to the initial setting state, and when the second count value is reached, the oscillation circuit is stopped, and the operation of the above instruction circuit is performed. By using a simple configuration in which the first counter for setting the order is set to an initial state, it is possible to eliminate the drawback of the conventional circuit that transmission becomes impossible without stopping oscillation. It can be used without wasting current consumption and can be used in a place with a bad environment and a lot of noise, and the practical effect is extremely large.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a remote control transmitter according to an embodiment of the present invention, and FIG.
Figure 3 is a block diagram showing an example of a conventional remote control transmitter; Figures 4, 5 and 6 are time charts for explaining the operation of Figure 3. Chart diagram, No. 7
The figure is an enlarged view of the key switch of the keyboard matrix in Figure 3, Figure 8 is a diagram showing an example of the timing of creating the key scan signal in Figure 3, and Figure 9 is a diagram showing an example of the key scan signal generation timing in Figure 3.
10 is a diagram showing an example of the input timing of the key input circuit shown in FIG.
It is a figure which shows the example of a setting of "1". 1...Oscillation circuit, 2...Timing generation circuit,
3... Keyboard matrix, 4... Scan output circuit, 5... Key input circuit, 6... Instruction circuit, 7... Counter (first counter), 8... Output circuit, 9... Judgment circuit , 10...
...Counter (second counter).

Claims (1)

[Claims] 1. An oscillation circuit that generates a reference signal and has an oscillation stop function, a timing generation circuit that receives the reference signal from this oscillation circuit and generates a timing signal, and m×n (m, n : an integer) keyboard matrix, a scan output circuit that outputs a scan signal to this keyboard matrix, a key input circuit that inputs signals from the keyboard matrix, and a key input circuit that determines key input from this key input circuit and transmits a transmission signal. an instruction circuit for setting the output timing of the instruction circuit; a first counter for setting the operation order of the instruction circuit; and an output circuit for inputting the output signal from the instruction circuit and outputting the transmission signal. , a determination circuit that determines a level change of an output signal connected from the instruction circuit to the output circuit; and a determination circuit that counts clocks from the timing generation circuit and is reset when the determination circuit determines a change in the output level. a second counter, the scan output is fixed at a constant level before the second counter finishes counting, the oscillation of the oscillation circuit is stopped at the time the second counter finishes counting, and the second counter A remote control transmitter characterized in that a counter of No. 1 is set to a constant count value.