JPH04207399A - Integrated circuit for remote control transmitter - Google Patents

Abstract

PURPOSE:To select optimum waveform shaping time in an envelope circuit to demodulate an infrared modulation signal input at learning time by varying the optimum waveform shaping time of the envelope circuit with software. CONSTITUTION:A photodiode 21 is provided to input the infrared signal of other remote control transmitter, an optical signal is converted to an electric signal. This electric signal is amplified by a signal amplifier 23, the infrared modulation signal 1 is outputted as a signal to an internal digital circuit. The learning is performed by signal processing the infrared modulation signal 1, a remote control output signal 30 is outputted from a control circuit 27 and a light emitting diode LED 28 is drived. Then, the waveform shaping time of the envelope circuit 25 to demodulate the infrared modulation signal input at the learning time is made variable with the software. Thus, the remote controllers with various kinds of modulating formation are corresponded by one integrated circuit 22.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to an integrated circuit for a remote control transmitter with a learning function.

[Summary of the Invention 1 This invention is an envelope circuit that demodulates an infrared modulation signal input during learning, by making the waveform shaping time of the envelope circuit variable using software, so that the optimum waveform shaping time can be selected. It is.

[Prior Art] In recent years, remote controllers for household i-products have become multi-functional, and there are many remote control transmitters with a so-called learning function that can store infrared signals from multiple remote control transmitters in one remote control transmitter. ) I started to create. In the case of learning, a function to receive infrared signals from other remote control transmitters is required, and usually a diode, a signal amplifier, an envelope circuit, and a control circuit for various signals are required. It is more effective to reduce costs by incorporating these elements into one integrated circuit as much as possible, and in fact, no consideration has been given to this. The infrared signal demodulation circuit, which was conventionally realized using a one-shot multi-trigger circuit, can now be realized by incorporating the function into an integrated circuit and using an envelope circuit that can be digitally processed.

[Problems to be Solved by the Invention] However, in the conventional envelope circuit, the waveform shaping time for demodulating the infrared signal is fixed, and therefore learning may not be possible depending on the modulation form of the infrared ini signal. For a remote control using such a special modulation form, a new integrated circuit having an envelope circuit with different waveform shaping times had to be created.

[Means for Solving the Problems 1] In order to solve the above problems, the present invention allows the waveform shaping time to be varied by software.

[Function] In a counter that counts waveform shaping time, prepare multiple signals that output time information, and use software to
[Embodiment 1] Hereinafter, an embodiment of the envelope circuit of the present invention will be explained based on the drawings. 5 First, a remote control with a learning eil function using the envelope circuit of the present invention In order to input the infrared signal of another remote control transmitter), an odd diode 21 (in order to input the infrared signal of another remote control transmitter) is removed, and the optical signal is converted into an electrical signal by kneading. Converted to 〢〢 This electric signal is amplified by the signal amplifier 23 and converted into infrared rays as a signal to the internal digital circuit. ! ! Outputs l signal l. The control circuit 27 learns by processing this infrared modulated signal 1.
A remote control output signal 30 is output from the
Drive 2B.

FIG. 3 is a timing diagram of FIG. 2 for explaining signal processing. The infrared modulated signal 1 is modulated with a carrier wave having a specific period (tl), a burst of carrier wave 0N
Data is expressed by 10FF. In other words,
The burst timer and the interval T2 until the next burst are its data representation. The envelope circuit 25 is a circuit for demodulating by removing a carrier wave, and produces an envelope signal]2. The waveform shaping time by the envelope circuit 25 is expressed as t. That is, if the next carrier wave pulse enters during the waveform shaping time t:2, the '1. , ” section will also be stretched. Therefore, the waveform shaping time ta must be longer than the period t of the carrier wave.Envelope signal 12
The edge pulse 29 is generated at the change point of T, the time 1''1 of the carrier wave burst is measured, and the time T2 until the next burst starts is measured.
If the number N of carrier wave pulses within the interval is determined, the frequency of the carrier wave can be calculated, and if the time data of T8 is known, the ON10 F F interval of the carrier wave burst can also be determined. When learning infrared signals from other remote controllers, use these T, ,T,
, N, and when transmitting by remote control, reproduce ff1 as learned based on this data. Since this mechanism is well known, details will be omitted. As mentioned above, the waveform shaping time t by the envelope circuit 25 must be longer than the carrier wave period t1, but if the waveform shaping time t is too long, the envelope signal J
The next carrier wave burst will enter in the interval where 2 is L''.This is because two carrier wave bursts will be mistaken as one carrier wave burst, so ifH must be 7t!! The infrared signal of the Okon transmitter has various forms of modulation, and it is desirable to make the waveform shaping time t2 variable according to the form. Therefore, the method shown in Fig. 1 was made possible using software. This is an envelope circuit of the present invention.An infrared modulated signal 1 modulated by a carrier wave is sampled by a sampling clock 2, and a reset signal 5 is generated at the beginning of the signal 1.When the reset signal 5 is output, All the counter F/Fs that count the waveform shaping time are reset, and the envelope signal 12 becomes L. Every time the count clock 6 falls, the counter F/F counts up, and the signals 7 to 1 are It changes as the output of the counter. If the selection signal 17 is at H" level, the envelope signal 12 becomes "H°" when 10 pulses of the count clock 6 are output after the reset signal 5 is output.
The counter F/F stops counting up. Signals 15 and 16 are preset data and write pulses, respectively, and are commonly used in a microcomputer IC operated by software. That is, only one of the six selection signals 17 to 20 for writing data into the preset register 13 by software and line decoding the data by the line decoder 14 becomes "H" level, and selects the time signal.

When the selection signal]7 is H, the waveform shaping time is the shortest, and in FIG. 4 (FIG. 4 is the timing diagram of FIG.
It is indicated by. When the selection signal 20 is H, the two-waveform shaping time is the longest and is indicated by section d.

The waveform shaping times a and -d are selected depending on the data written to the preset register 13, and can be managed by software.

[Effects of the Invention] As explained above, the present invention uses software to make the waveform shaping time for demodulating modulated infrared input variable, thereby making it possible to use remote controllers with various modulation formats (as opposed to one remote controller). This has the advantage that it can be handled using integrated circuits.

[Brief explanation of the drawing]

Figure 1 is an envelope circuit diagram of the present invention, Figure 2 is an integrated circuit diagram for a remote control transmitter with a learning function using the circuit in Figure 1, and Figure 3 is the timing diagram in Figure 2 during learning. figure,
FIG. 4 is a timing diagram of the circuit shown in FIG. 1...Infrared modulation signal 2... 1 sampling clock 3...1
Sampling signal 5... Reset signal 6... Count clock 12... Envelope signal 13... Preset register 14... Line decoder 15... Preset data 16... Write pulses 17 to 20- Selection signal 21...) Odd diode 22... Integrated circuit 23...Signal amplifier 24...Sampling circuit 25...Envelope circuit 26... - Edge pulse generation circuit 27... Control circuit 28... Light emitting LED 29... Edge pulse 30... Remote control output signal and above Applicant Seiko Electronics Co., Ltd. Agent Patent attorney Toshiyuki Hayashi Sukeri 7-1-1-
H1 Hayabusa bending circuit v-]g, 2 ``heat, q' -JL-1--~-,-,-,,,,JL
, -7-- No --- Figure 2 Gui, Nofu ['Tsukifu 131 to 1

Claims (1)

[Claims] In integrated circuits for remote control transmitters with learning functions,
An integrated circuit for a remote control transmitter, characterized in that the waveform shaping time of an envelope circuit that demodulates an infrared modulated signal input during learning is made variable by software.