JPH0459836B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an infrared wireless remote control used in consumer VTRs, TVs, etc., and is applicable when it is necessary to transfer a large amount of data such as timer reservations. This invention relates to an infrared remote control method that reduces the time required for data transfer.

<Prior Art> In an infrared wireless remote control, the same data is transmitted twice, and the latter data is an inversion of the previous data. This is to determine whether the received signal is transmission data or disturbance noise on the receiving side, and if the data received twice is the same data, it is determined that it is transmission data. The first signal of the data transmitted twice is called the front signal, and the second signal is called the back signal. FIG. 4 shows the timing of transmission of the front signal and the back signal.

Figure 5 shows an example of a front signal and a back signal, and in the figure,
a is a front signal, and b is a back signal. After the 6th bit of the signal, the back signal is an inversion of the front signal. c indicates an example of a signal pulse interval, and d indicates a waveform of a carrier signal constituting each pulse.
38kHz is generally used as the carrier frequency.

<Problems to be solved by the invention> In the conventional infrared wireless remote control,
A pulse position modulation method is used that modulates the frequency interval depending on the data. However, in the infrared wireless remote control, the data transfer rate is limited due to the response speed of the light receiving side. Therefore, the pulse position modulation method described above has the disadvantage that when attempting to transmit a large amount of data, the transfer time becomes long, and the amount of data transferred at one time is limited to several tens of bits at most. Furthermore, since the transmitter is held in the hand and transmitted toward the device, there is a problem in that it is troublesome for the user to point the transmitter in a fixed direction for a long time.

<Means for Solving the Problems> The present invention provides an infrared light wireless remote control in which infrared light pulses having multiple types of pulse intervals and multiple types of carrier frequencies are used as control signals, and pulses corresponding to data are used as control signals. and transmitting a control signal having an interval and a carrier frequency.

<Function> The infrared light remote control method according to the present invention uses a composite modulation method having a pulse interval and a carrier frequency corresponding to the data, thereby transmitting multiple bits of data in the conventional 1-bit transmission time. .

<Example> Figure 1 shows the waveform of a transmission signal in the infrared remote control method of this example.
is a front signal, b is a back signal, and c is a carrier signal constituting the back signal. Further, FIG. 2 shows the timing of the front signal and the back signal, and the cycle of the front signal and the back signal is 32 ms.

The first bit of the signal is represented by the carrier frequency. For example, when the carrier frequency is 38kHz, it is set as "1", and when the carrier frequency is 57kHz, it is set as data "0". The second bit of the signal is represented by the pulse interval. For example, if the interval until the next pulse is 2ms, the data is “1”
When the interval to the next pulse is 1 ms, the data is set to "0".

To explain according to Fig. 1, the first pulse S1 of the back signal shown in b has a carrier frequency of 38kHz as shown in c, so it is data "1", and this pulse S1 and the next pulse S2 The distance between
ms, the second bit is data "1". As shown in c, the carrier frequency of the second pulse S2 is 57kHz, so the third bit is data "0". Thereafter, data corresponding to the carrier frequency of the pulse and data corresponding to the pulse interval are alternately determined in the same manner. That is, two bit data are determined for one pulse.

Although the above explanation is about the back signal, the same applies to the front signal.

FIG. 3 shows the configuration of a transmitting circuit that implements this method. In the figure, 1 is a remote control LSI, 2 is a carrier signal generation circuit, 3 is a logic circuit, 4 is a driving transistor, and 5 is an infrared light emitting diode.

The first bit output of the remote control LSI 1 outputs a signal for selecting a carrier frequency corresponding to the transmission data. The second bit output of the remote control LSI 1 outputs pulses at intervals corresponding to the transmitted data. Depending on the first bit output “1”, “0”
38 kHz or 57 kHz is selected, and the pulse of the second bit output drives the transistor 4 with this carrier frequency, and the infrared light emitting diode 5 outputs infrared light. On the light receiving side, the carrier frequency and pulse interval of the infrared light pulse are determined, and two bits of data are read.

In the above embodiment, data is expressed using two types of pulse intervals and two types of carrier frequencies, but it is also possible to express data using more types of pulse intervals and carrier frequencies. be. In this case, more data can be transferred in a certain period of time.

<Effects of the Invention> As explained above, in the present invention, data is expressed by the carrier frequency as well as the pulse interval, so the data transfer rate can be increased without increasing the response speed on the light receiving side.
For example, when transmitting a large amount of data such as a reservation remote control, the transmission time can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the signal waveform of the embodiment of the present invention, FIG. 2 is a timing chart of front signals and back signals of the embodiment of the present invention, FIG. 3 is a diagram showing the block configuration of the embodiment of the present invention, and FIG. The figure is a timing chart of the front signal and the back signal of the conventional example, and FIG. 5 is a diagram showing the signal waveform of the conventional example. 1... Remote control control LSI, 2... Carrier signal generation circuit, 3... Logic circuit, 4... Transistor, 5... Infrared light emitting diode.

Claims (1)

[Claims] 1 In an infrared light remote control method that wirelessly controls a device by transmitting a control signal using infrared light as a signal medium to the device, there are multiple types of pulse intervals and multiple types of carrier frequencies. An infrared light remote control method characterized by using infrared light pulses as a control signal and transmitting a control signal having a pulse interval and carrier frequency corresponding to data.