JPS58184897A - Receiving device of remote control signal - Google Patents

Abstract

PURPOSE:To prevent malfunction due to noise, by eliminating a received pulse signal if it is shifted from a predetermined pulse width. CONSTITUTION:A photodetector 2 is connected to the input side of a wave shape device 4 via a tuning amplifier 3. The output of the device 4 is connected to the input of integration circuits 10, 11 and the output of the circuit 10 is connected to one input of a comparator 12 and the output of the circuit 11 is connected to one input of a comparator 13. The other input of the comparator 12 is connected to the 1st reference voltage 14 and the other input of the comparator 13 is connected to the 2nd reference voltage 15. The output of the comparator 12 is connected to a decoder 9 via a switching device 8. The output of the comparator 13 is connected to a switching signal input of the device 8. The decoder 9 is provided with a reset circuit 17 releasing the decoding.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a receiving device for remote control pulse signals such as a video tape recorder, and particularly to a receiving device having a function of preventing malfunctions caused by noise.

The case where light is used as the remote control pulse signal will be explained as an example. - Figures 1 and 2 show the optical remote control pulse most commonly used at present. Figure 1 shows a carrier wave, and the carrier frequency is, for example, 20K.
It is HZ. In the figure, Tp stands for the pulse width time constituting one remote control pulse, which in this case is 500 μs. FIG. 2 shows the code format of the control t~roll signal, and codes 0 and 1 are distinguished by pulse Ill intervals. That is, in the figure, 1 c' r o extends code 0, and [1 indicates code 1. In this case, 1LO1+2-S, and TI is 4i
It is S. The remote control command 1iI consists of 10 bits, and the time 7'w allocated for one edict transmission is 4.
It is 81S.

The above numerical values are the most commonly used values, but are not necessarily limited to these.

FIG. 3 is a schematic block diagram showing a conventional optical remote control pulse signal receiving device.

In the configuration, a photodetector 2 is connected to a waveform shaper 4 via a tuned amplifier 3. The output side of the waveform shaper 4 is connected to one switching terminal of the switching device 8 and the integrating circuit 5. The output side of the integrating circuit 5 is connected to one input terminal of a comparator 6, and the other input side of the comparator 6 is connected to a reference voltage 7. The output side of comparator 6 is open/close 1! @8
Connected to the open/close signal input side of the A switching terminal other than the one switching terminal of the switching device 8 is connected to a decoder 9.
connected to.

When the light pulse signal (81) is received, the photodetector 2 performs photoelectric conversion. Conversion is performed. Tuned amplification!13+t receives the charged and converted pulse signal and amplifies and outputs only the signal composed of components equal to the carrier frequency.The frequency of the noise matches the carrier frequency. When the noise is amplified and output, the amplified output is waveform-shaped by the waveform shaper 4 and then sent to the decoder 9. Therefore, the pulse interval of the pulse signal whose waveform has been shaped based on the noise is determined by the format of the remote control signal (
Said T. O, 'TI'), the risk of malfunction increases. To eliminate the cause of this malfunction,
The illustrated conventional device has the following functions. That is, the pulse signal whose waveform has been shaped is integrated by the integrating circuit 5 and is applied to one input side of the comparator 6, and the other input side of the comparator 6 is supplied with the normal pulse width time (in the above example, dp-). 500 μs) is given as the reference voltage. ] When the integral input becomes larger than the reference voltage, the comparator drives the switching device 28 to cut off the connection between the waveform shaper 4 and the decoder 9. The intent of this function is to block signals that have a pulse width larger than the regular pulse width compatible with the format of the remote control pulse signal. However, as explained below, that intention is never achieved.

FIGS. 4A and 4B show waveforms of various parts of the conventional device shown in FIG. 3 during fluorescent irradiation. Figure 4A shows the case of a quick fluorescent light with pulse lighting, and Figure I'lJB shows the case of a normal quick fluorescent light. In Figures 4A and 148, (1) is tuned amplification! Il13 output waveform, (2)
(3) shows the output waveform of the waveform shaping 14, and (3) shows the input waveform to the decoder 9. Each of the finely spaced vertical lines in Figure 14A (1) represents one pulse.

These waveforms are greatly enhanced by the sharpness of the Kikkorection, and the case shown is merely an example.

In the output waveform (2) after waveform shaping shown in Figure 1 in MJA and Figure 4B, pulse a has a pulse width larger than the regular pulse width of the remote control pulse signal.
I C, a pulse having a pulse width equal to the normal pulse width d1 There are pulses b, e, f having a pulse width smaller than the normal pulse width. For pulses a and c, the above-mentioned cutoff mechanism in which the integrating circuit 5, comparator 6, reference voltage 7, and switching device 8 operate operates to cut off pulses a and c at the time width p, so that the decoder The human power pulses to 9 are a' and c', respectively.The cutoff mechanism does not operate for the other pulses b, d, e, and f, and the pulses b, d, e, and r are input to the decoder 9 as they are. Therefore, the manual pulse to the decoder 9 becomes as shown in FIGS. 4A and 4B (3).As is clear from the above explanation, in the conventional device, the pulse width is larger than the normal pulse width. Pulses with h are forced to fit the normal width, but are not removed. Also, pulses with a pulse width smaller than the normal pulse width are sent to the decoder as they are without any hindrance. Regarding equipment, there was a risk of malfunction due to noise.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a remote control pulse signal receiving device in which pulse signals having a pulse width other than the normal pulse width are selectively removed.

This invention provides a method for decoding when the receiving pulse (#! The information is decoded by generating a pulse signal and detecting the leading edge at the decoder 9, and the received pulse signal is transmitted over a certain time width which is predetermined to be slightly larger than the normal pulse interval. When the decoding pulse signal has a large time width, the decoding pulse signal is prevented from being sent to the decoder, and the decoding of the decoder is canceled.

The foregoing objects and other objects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the drawings.

FIG. #15 is a schematic block diagram showing an optical remote control pulse signal receiving device, which is an embodiment of the present invention. In the configuration, the photodetector 2 is connected via a quadruple amplifier 3 to the input side of a waveform shaper 4. The output side of the waveform shaper 4 is connected to the input side of the integrating circuit 10 and the integrating circuit 11, respectively. 13, respectively.

The other input terminal of the comparator 12 is connected to a first reference voltage 14.
The other input side of the comparator 13 is connected to the second reference voltage 15. The output side of the comparator 12 is connected to a decoder 9 via a switching device 8. The output side of the comparator 13 is connected to the switching signal input side of the switching device 8. The decoder 9 is provided with a reset circuit 17 for canceling decoding.

In operation, regardless of whether it is a remote control signal or noise, the optical pulse signal 1 is processed by the waveform shaper 4 (') until the waveform is shaped and output, as in the case of the conventional device described above.This waveform shaped output is integrated. It is integrated by the circuit 10 and given to one input side of the comparator 12.The other input side of the comparator 12 has a pulse having a regular pulse width of the remote control signal integrated by the integrating circuit 1o. A voltage of - which is slightly smaller than the voltage value is given as the first reference voltage.''The inverter 12 is
When the integrated output of the integrating circuit 10 becomes larger than the first reference voltage, a pulse signal (decoding pulse signal) to be sent to the decoder 9 for signal decoding is output. In other words, the decoding pulse signal is not output for the pulse tgs which has a pulse width smaller than the regular pulse width of the remote control (g@).The decoder 9 receives the decoding pulse signal. The leading edge of the pulse signal is detected, and the leading edge of the pulse signal is decoded according to the interval. The pulse width of the decoding pulse signal corresponding to the pulse signal having the regular pulse width is This is determined by the time constant of the integrating circuit 10 and the first m quasi i1 intersection 14, but as mentioned above, the information necessary for decoding the decoder 9 is determined by the time width of the decoding pulse signal, not by IJ, but by the leading edge. Therefore, the am width can be set excessively as long as it is not too crowded or too small.In addition, the pulse l!IFiA (TO, T1 mentioned above) of the original remote control pulse signal is changed by the above operation. It is clear that the distance between the leading edges of the decoding pulse signal without being received is replaced.

In parallel with the above 1 operation, the waveform shaping output is
11 and applied to one input side of the comparator 13] The other input side of the comparator 13 receives the voltage - when the pulse having the regular pulse width of the remote control signal is integrated by the integrating circuit 11. A voltage with a slightly larger value is given as the second reference voltage. The comparator 13 indicates that the integral output of the integrating circuit 11 is W4.
2, outputs a trigger pulse for triggering the pulse generator 16. The pulse generator 16 is triggered by this trigger pulse, outputs a pulse signal with a predetermined constant time width lr, opens and closes @lf8, and connects the comparator 12 and the decoder 9 for the time T''. On the other hand, the decoder 9 is provided with a reset circuit 17 that cancels the decoding when the decoding pulse signal is not input for the time period 7r or more.

Therefore, when the decoding pulse signal is cut off by the switching device 18, the decoding of the decoder 9 can always be reset at the same time.

, :1.

In other words, for a pulse signal having a pulse width larger than the regular pulse width of the remote control No. m, a decoding signal is generated and sent to the decoder 9. 9 is immediately blocked, and the decoding of decoder 9 is reset.

As an example of a specific numerical value, the above-mentioned Oi@ format (
Carrier frequency -20Ktlz, Tp =500μS,'
l'0=21S, TI-IS, 11i10-bit configuration, I'W=48118), the first and second reference voltages are each converted into a pulse time width of 3.
00 μs and 700 μs, and d = bO■S. This number of wheels is determined by *experience.
It has been confirmed that very good results can be obtained.

Note that the above-mentioned integration circuits 10 and 11 may be shared.
'' function, and has the same effect as the above-mentioned embodiment. Also, although the case where the remote control signal is an optical pulse signal has been explained, other signals such as 11N rutted waves may also be used.
It can also be used in the case of .

As described above, according to the present invention, a pulse signal having an irregular pulse width can be reliably removed, and a remote control pulse signal receiving apparatus that does not malfunction due to noise can be obtained.

[Brief explanation of the drawing]

FIG. 3 is a schematic block diagram illustrating a conventional optical remote control pulse signal receiving apparatus. FIG. 5 is a schematic block diagram showing a receiving device for a light control pulse signal, which is an embodiment of the present invention. In the figure, Tp is the pulse width time constituting one remote control pulse, To is the pulse interval representing code 0, T1 is the pulse interval representing code 1, 1 is the optical pulse signal, 2 is the photodetector, 3G1 Tuned amplifier, 4 is a waveform shaper, 5, 10.11 is an integrating circuit, 6, 12.13 is a comparator, 7° 14.15μ base single voltage, 8 is a switchgear, 9 is a decoder, 16 is a pulse generator, 17 is a reset circuit, (1) is the output signal waveform of Ii[l amplifier 3, (
2) is the output of waveform shaping 14) 1A waveform, (3) is 1
Figure 3 shows the waveform of the input signal to the de-der 9 in the 1st grade carp.1e

Claims (3)

[Claims] (1) A device for receiving a pulse signal having a predetermined first time width for remotely controlling a video tape recorder, etc., wherein the received pulse signal is slightly smaller than the first time width. means for generating a decoding pulse signal used for decoding information for remote control when the time width is larger than a second time width determined to be smaller than a second time width; and a means for receiving the decoding pulse signal. means for decoding information for performing remote control using a remote controller; A remote control signal receiving device comprising: means for preventing a decoding pulse signal from being sent to the decoding means for a predetermined period of time or more. (2) The pulse signal is an optical pulse signal, and the decoding means erases the information decoded until then when the decoding pulse code is not input for a certain period of time or more.
2. The remote control signal receiving device according to claim 1, wherein the blocking means is a means for cutting off a connection between the decoding pulse signal generating means and the decoding means for a predetermined period of time or more. Device. (3) The remote control signal receiving device according to claim 1 or 2, wherein the decoding means is a means for detecting and decoding a preceding track of the decoding pulse signal.