JP2002369273A - Remote control signal reproducing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reproduce an appropriate remote control signal from a received pulse modulation signal, even if a leader pulse signal affected by noise is received. SOLUTION: In the remote control signal reproduction apparatus for receiving a pulse modulation signal, to which a transmission start pulse signal and a transmission end pulse signal are added and for reproducing a remote control signal from the received pulse modulation signal, a specific number of pulses of pulse signals from a pulse signal next to the first pulse signal of a pulse signal which is modulated by the received pulse modulation signal are extracted for reproducing a custom code signal, and a specific number of pulse signals from the next pulse following the custom code signal are extracted, when it is determined that the custom code signal is the custom code signal of a specific remote controller, thus reproducing the remote control signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote control signal reproducing apparatus for reproducing a remote control signal of an infrared signal transmitted from a remote control for remote control of a television receiver, a video device or the like.

[0002]

2. Description of the Related Art The prior art is disclosed in, for example,
As described in Japanese Unexamined Patent Publication No. 700, a level of an input signal in a signal format in which a signal is formed by a continuous length of a high level of a binary level is sampled, and a sampling signal is output. When the count value is greater than a predetermined value, the input signal is determined to be “1”. When the count value is less than the predetermined value, the input signal is determined to be “0”. Generates a signal and samples from a period longer than the low-level duration minus a period corresponding to a predetermined number of sampling signals and from the sum of the low-level duration and the high-level short duration By stopping sampling for a period shorter than the period obtained by subtracting the period corresponding to the predetermined number of signals, noise may be mixed in the signal. It was something which is adapted to reproduce the remote control signal to shorten the time for the determination of have a high level.

Further, as described in Japanese Patent Publication No. 2-51319, for example, the number of pulses input during a certain period after the first pulse of the received signal is input is counted, and the counted pulses are counted. The number is output as a remote control signal only when the number is equal to or less than a certain number smaller than the number of pulses obtained from the pulse period and the period determined by the modulation frequency, and the number of pulses input for a certain period after the certain period is counted. When the measured number of pulses is less than the set number of pulses that is smaller than the number of pulses that should be in the certain period, the operation of determining the remote control signal is stopped, and the number of pulses input in the certain period after the certain period is reduced. When the counted number of pulses is smaller than the number of pulses when a legitimate signal is input during a period corresponding to a certain period and is larger than a certain number that is not zero, a reset is performed. So as to stop the determination operation of the con signal, there is those from an input signal including an impulsive noise to reproduce the remote control signal.

[0004]

However, in the above-mentioned conventional technique, a remote control signal can be reproduced from a pulse modulation signal containing noise. However, a reader pulse signal indicating the start of transmission of the remote control signal has no signal. The first signal received in the state, is susceptible to noise,
Also, in the no-signal state, there is a problem that noise is often received as a signal similar to the leader pulse signal.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and is intended to reproduce a correct remote control signal from a received pulse modulation signal even when receiving a reader pulse signal affected by noise. What you want to do.

[0006]

In order to achieve the above object, according to the present invention, a pulse modulated signal of a remote control signal to which a transmission start pulse signal and a transmission end pulse signal are added is received, and the received pulse modulated signal is received. A remote control signal reproducing apparatus for reproducing a remote control signal from a demodulation means for demodulating a pulse signal from a received pulse modulation signal; Reproducing means for reproducing the remote control signal by determining the length of the pulse period of the pulse signal having the predetermined number of pulses extracted by the extracting means; and a remote control signal reproduced by the reproducing means being a signal from the predetermined remote control. Determining means for determining whether or not the pulse signal is demodulated from the received pulse modulated signal. A pulse signal of a predetermined number of pulses is extracted from the next pulse signal following the pulse signal of the above, and the first remote control signal is reproduced, and it is determined that the first remote control signal is a signal from the predetermined remote control. When the first
Then, a predetermined number of pulse signals are extracted from the next pulse signal following the remote control signal, and the second remote control signal is reproduced.

[0007] The apparatus further comprises detection means for detecting an error in the remote control signal reproduced by the reproduction means,
Extracting a pulse signal of a predetermined number of pulses from the next pulse signal following the remote control signal, reproducing a third remote control signal, collating the second remote control signal with the third remote control signal, An error in the second remote control signal is detected.

By these means, even if a reader pulse signal affected by noise is received, a correct remote control signal can be reproduced from the received pulse modulation signal.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings as appropriate. FIG. 1 is a block diagram showing a configuration of a remote control signal reproducing device according to an embodiment of the present invention. FIG. 2 is an explanatory diagram showing signals of the remote control signal reproducing device according to the embodiment of the present invention. 5 is a flowchart showing an operation of the remote control signal reproducing device according to the embodiment of the present invention.

First, a description will be given based on a block diagram showing the configuration of a remote control signal reproducing apparatus according to an embodiment of the present invention shown in FIG.

The remote control is provided with a plurality of keys for transmitting a command signal. Each time a key is pressed, a predetermined custom code signal for identifying the remote control is assigned to a key of the pressed remote control. The transmitted key code signal is transmitted as a remote control signal.

[0012] The key code signal is, for example, a power ON / OFF signal.
The OFF key is hexadecimal "01", the numeric keypad "1" to "9" is hexadecimal "05" to "0D",
The small operation keys are assigned as hexadecimal numbers "23" and "24".

The remote control signal includes a custom code signal for identifying the remote control, a key code signal assigned to a key of the remote control, and an inverted key code signal for detecting an error in the received key code signal. And a reader pulse signal indicating the start of transmission of a remote control signal before and after the infrared signal of the pulse modulation signal of the carrier frequency modulated by the pulse position modulation method in which "0" and "1" are defined by the length of the signal. A trailer pulse signal indicating the end of transmission of the remote control signal is added and transmitted.

The pulse modulated signal transmitted from the remote controller is received by the light receiving section 1, converted from an infrared signal to an electric signal, and the pulse modulated signal converted into the electric signal is amplified by the amplifier circuit 2 because it is a weak signal. Then, it is sent to the filter circuit 3.

The filter circuit 3 is composed of a band-pass filter having a carrier frequency as a center frequency, and extracts a signal at the carrier frequency. The filter circuit 3 removes natural light, disturbance light from lighting equipment, noise, and the like. Has become.

From the pulse modulation signal sent to the filter circuit 3, a signal of the carrier frequency is taken out, sent to the detection circuit 4, where the pulse signal is demodulated, and the demodulated pulse signal is subjected to waveform shaping by the waveform shaping circuit 5. It is shaped and sent to the microcomputer 6.

The microcomputer 6 extracts a predetermined number of pulse signals from the pulse signals shaped by the waveform shaping circuit 5, determines the length of the pulse period of the extracted pulse signals, and reproduces the remote control signal. A control signal based on the reproduced remote control signal is transmitted to the peripheral device, and a command operation transmitted from the remote control is executed.

Next, a description will be given based on an explanatory diagram showing signals of the remote control signal reproducing apparatus according to the embodiment of the present invention shown in FIG.

FIG. 2A shows a signal transmitted from the remote controller. The signal transmitted from the remote controller is transmitted as a combination of signals according to a predetermined format. In the figure, a reader pulse signal indicating the start of transmission of a remote control signal, a custom code signal (8-bit “11010100”) for identifying the remote control, and a key code signal (4 Bit "0100"), an inverted key code signal (4-bit "1011") for detecting an error in the received key code signal, and a trailer pulse signal indicating the end of remote control signal transmission. Is shown.

The remote control signal is transmitted as a pulse modulation signal of a pulse position modulation system capable of transmitting a plurality of code signals with an equal pulse width and a variable pulse period. For example, when the carrier frequency is 36.7 kHz, the pulse width is 0.56 ms, and the pulse cycle is 1.12 ms.
Is defined as "0", and the pulse period is defined as "1" when the pulse period is 2.25 ms, and a custom code signal, a key code signal, and an inverted key code signal represented by a binary number are transmitted as a pulse modulation signal. .

The leader pulse signal indicating the start of transmission of the remote control signal is wider than the pulse width of the pulse signal of the remote control signal to distinguish it from the pulse signal of the remote control signal. After the signal transmission, a pause period of 2.25 ms is provided. The trailer pulse signal indicating the end of the transmission of the remote control signal has a pulse width of 0.56 ms, which is the same as the pulse width of the remote control signal. Is provided.

After the trailer pulse signal is transmitted, the reader pulse signal and the trailer pulse signal are repeatedly transmitted at a cycle of 108 ms while the key of the remote controller is still pressed.

FIG. 2 (b) schematically shows a pulse-modulated signal pulse-modulated by the remote control signal of FIG. 2 (a). When the remote control signal is at a low level, it is modulated. This indicates that a pulse-modulated signal of the carrier frequency is transmitted.

By transmitting an infrared signal of a pulse-modulated signal having a modulated carrier frequency, it is possible to reduce the influence of natural light, disturbance light such as lighting equipment, and noise.

However, as shown in FIG. 2C, the received pulse modulation signal is affected by noise, and the pulse width of the received leader pulse signal is wider than the pulse width of the original leader pulse signal. May be. When the pulse-modulated signal is not received, the gain of the amplifier that amplifies the received signal is maximized, so that faint external noise is also amplified and the noise is likely to be mixed.

In particular, the leader pulse signal is a signal that is received first when a remote control signal is not received, and a carrier frequency component included in noise or the like immediately before the leader pulse signal is amplified and the original signal is amplified. , A pulse signal similar to the leader pulse signal appears in a portion before the head of the leader pulse signal, and the pulse width of the original leader pulse signal is often widened. Further, a signal similar to the reader pulse signal may be mixed even though the remote control signal is not received.

According to the present invention, when the pulse modulation signal is received, an interrupt signal of the microcomputer is generated at the falling edge of the first pulse signal, and the control of the microcomputer is shifted to a remote control signal reproduction process, and the first pulse is received. A pulse signal of a predetermined number of pulses (8 bits in FIG. 2C) is extracted from the next pulse signal following the signal as a custom code signal,
Comparing the extracted custom code signal with a predetermined custom code signal to determine whether the custom code signal is correct; and when determining that the extracted custom code signal is a signal from a predetermined remote controller. A pulse signal of a predetermined number of pulses (4 bits in FIG. 2C) following the custom code signal is a key code signal, and a predetermined number of pulses following the key code signal (4 bits in FIG. 2C). The pulse signal is extracted as an inverted key code signal, the length of the pulse period is determined, and each signal is reproduced.

By doing so, a correct remote control signal can be reproduced without being affected by the reader pulse signal affected by noise.

If the custom code signal is not a predetermined custom code signal, it can be determined that the received signal is not a signal transmitted from a predetermined remote controller, and a signal similar to the reader pulse signal due to noise or the like. Can be prevented from malfunctioning due to the signal.

Further, by comparing the received key code signal with the inverted key code signal, an error in the received key code signal can be detected. When the key code signal affected by noise is received, A malfunction due to an incorrect key code signal can be prevented.

Next, the operation of the remote control signal reproducing apparatus according to the embodiment of the present invention will be described with reference to the flowchart of FIG.

When a remote control signal is received, an interrupt signal of the microcomputer is generated at the falling edge of the reader pulse signal.
The microcomputer shifts to the process of reproducing the received remote control signal, and proceeds from step S1 to step S2 to extract a predetermined number of pulse signals from the next pulse signal following the first pulse signal received. After judging the length, a custom code signal having a predetermined number of bits is reproduced, and the process proceeds to step S3.

In step S3, it is determined whether or not the reproduced custom code signal is a predetermined remote control custom code signal. If the reproduced custom code signal is a predetermined remote control custom code signal, step S4 is performed. If the extracted custom code signal is not the custom code signal of the predetermined remote controller, the process proceeds to step S8.
To end the process.

In step S4, a pulse signal of a predetermined number of pulses is extracted from the next pulse signal following the custom code signal, the length of the pulse period is determined, and a key code signal of a predetermined number of bits is reproduced. Proceed to S5.

In step S5, a predetermined number of pulse signals are extracted from the next pulse signal from the next pulse signal following the key code signal, the length of the pulse period is determined, and the inverted key code of a predetermined number of bits is determined. The signal is reproduced, and the process proceeds to step S6.

In step S6, the reproduced key code signal is compared with the reproduced inverted key code signal, and if it is determined that there is no error in the reproduced key code signal, the process proceeds to step S7, where the reproduced key code signal is reproduced. If it is determined that there is an error in the code signal, the process proceeds to step S8 and ends.

In step S7, a command operation of the received key code signal is executed, and the flow advances to step S8 to end the processing.

When the key code signal is not affected by noise, it is not necessary to detect an error in the key code signal, and it is not necessary to extract and reproduce an inverted key code signal from the received pulse modulation signal. Good.

[0039]

As described above, according to the remote control signal reproducing apparatus of the present invention, a predetermined pulse number is calculated from the next pulse signal following the first pulse signal of the pulse signal demodulated from the received pulse modulation signal. It is determined whether or not the received remote control signal is a signal from a predetermined remote control, and if the received remote control signal is a signal from the predetermined remote control, , And the remote control signal can be reproduced. Further, a predetermined number of pulse signals can be extracted from the next pulse signal to detect an error in the reproduced remote control signal. Thus, even if a reader pulse signal affected by noise is received, a correct remote control signal can be reproduced from the received pulse modulation signal.

According to the first aspect of the present invention, a remote control signal reproducing apparatus reproduces a custom code signal from a next pulse signal following a first pulse signal of a pulse signal demodulated from a received pulse modulation signal, and When it is determined that the signal is a remote control custom code signal, the key code signal is reproduced from the next pulse signal following the custom code signal,
Furthermore, the next pulse signal following the key code signal is reproduced,
An error of the key code signal is detected.

According to a second aspect of the present invention, a remote control signal reproducing apparatus reproduces a remote control signal from a next pulse signal following a first pulse signal of a pulse signal demodulated from a received pulse modulation signal, and outputs the signal from a predetermined remote control. When it is determined that the signal is a remote control signal, the remote control signal is reproduced from the next pulse signal.

According to a third aspect of the present invention, a remote control signal reproducing apparatus reproduces a custom code signal for identifying a remote control and a key code signal assigned to a key of the remote control from the received pulse modulation signal.

According to a fourth aspect of the present invention, a remote control signal reproducing apparatus extracts a predetermined number of pulse signals from the next pulse signal following the remote control signal and detects an error in the reproduced remote control. I have.

According to a fifth aspect of the present invention, there is provided a remote control signal reproducing apparatus for comparing a key code signal with an inverted key code signal obtained by inverting each bit of the key code signal to detect an error in the key code signal. ing.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a remote control signal reproducing device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing signals of the remote control signal reproducing device according to the embodiment of the present invention.

FIG. 3 is a flowchart showing an operation of the remote control signal reproducing device according to the embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 light receiving unit 2 amplifier circuit 3 filter circuit 4 detection circuit 5 waveform shaping circuit 6 microcomputer

Claims (5)

[Claims] 1. A remote control signal reproducing apparatus for receiving a pulse modulation signal of a remote control signal to which a transmission start pulse signal and a transmission end pulse signal are added and reproducing the remote control signal from the received pulse modulation signal. Demodulating means for demodulating a pulse signal from the modulated signal, extracting means for extracting a predetermined number of pulse signals from the pulse signal demodulated by the demodulating means, and pulse signal having a predetermined number of pulses extracted by the extracting means Reproducing means for reproducing the remote control signal by determining the length of the pulse cycle of the signal; determining means for determining whether the remote control signal reproduced by the reproducing means is a signal from a predetermined remote control; Detecting means for detecting an error in the remote control signal reproduced by the A pulse signal of a predetermined number of pulses is extracted from the next pulse signal following the first pulse signal of the pulse signal, and a custom code signal for identifying the remote control is reproduced. When it is determined that the signal is a signal, a predetermined number of pulse signals are extracted from the next pulse signal following the reproduced custom code signal, and the key code signal assigned to the key of the remote controller is reproduced. A pulse signal of a predetermined number of pulses is extracted from the next pulse signal following the key code signal, and an inverted key code signal for detecting an error of the key code signal is reproduced, and the key code signal and the inverted key signal are reproduced. A remote control signal reproducing device, wherein an error of the key code signal is detected by collating with a code signal. 2. A remote control signal reproducing apparatus for receiving a pulse modulation signal of a remote control signal to which a transmission start pulse signal and a transmission end pulse signal are added and reproducing the remote control signal from the received pulse modulation signal. Demodulating means for demodulating a pulse signal from the modulated signal, extracting means for extracting a predetermined number of pulse signals from the pulse signal demodulated by the demodulating means, and pulse signal having a predetermined number of pulses extracted by the extracting means A reproducing means for reproducing the remote control signal by determining the length of the pulse cycle of the signal; and a determining means for determining whether or not the remote control signal reproduced by the reproducing means is a signal from a predetermined remote control. A predetermined number of pulses from the next pulse signal following the first pulse signal of the pulse signal demodulated from the modulated pulse modulation signal. The first remote control signal is reproduced by extracting the first remote control signal from the next pulse signal following the first remote control signal when it is determined that the first remote control signal is a signal from a predetermined remote control. A remote control signal reproducing apparatus characterized in that a pulse signal having a predetermined number of pulses is extracted and a second remote control signal is reproduced. 3. The remote control signal according to claim 1, wherein the first remote control signal is a custom code signal for identifying the remote control, and the second remote control signal is a key code signal assigned to a key of the remote control. The remote control signal reproducing device according to claim 2. 4. A detecting means for detecting an error in a remote control signal reproduced by said reproducing means, wherein a predetermined number of pulse signals are extracted from a next pulse signal following said second remote control signal. Play the remote control signal of 3,
3. The remote control signal reproducing device according to claim 2, wherein the second remote control signal is compared with the third remote control signal to detect an error in the second remote control signal. 5. The remote control signal reproducing apparatus according to claim 4, wherein the third remote control signal is an inverted key code signal obtained by inverting each bit of the key code signal.