JPS6055745A - Transmitting circuit for remote control - Google Patents

Abstract

PURPOSE:To shorten the response time by making it possble to judge whether every one bit of a detection signal is correct or not in the receiving circuit side. CONSTITUTION:Signals K1-K8 inputted from a key switch matrix 5 are detected by a key input detecting circuit 14 and are supplied to an encoded signal generating circuit 15 to generate an encoded signal, and this signal is inverted for every bit signal, and inverted signals and individual bit signals before inversion are supplied to an output synthesizing circuit 17. These inverted signals are added to bit signals in the output synthesizing circuit 17 so that each bit signal and the following signal are certainly different in level from each other. Thus, it is possible to judge whether every one bit of the detection signal is correct or not in the receiving circuit side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a transmitter circuit for remote control used in consumer equipment and communication industry equipment.

[Technical background of the invention and its problems]

Recently, an increasing number of consumer devices such as televisions and home stereos are adopting remote control systems that use infrared rays as a signal medium. The remote control transmitter circuit used in such systems is
Today, most of its main parts are integrated. FIG. 1 is a block diagram showing a general circuit configuration of a remote control transmitting circuit using infrared rays as a signal medium. In FIG. 1, 1 is an integrated electronic circuit section,
This electronic circuit section 1 is provided with output terminals for timing signals T and x'l', 8 input terminals for key input signals, and an output terminal for a modulated output signal OUT. Between the output terminals of the signals T and ~T4 and the input terminals of ~ and 8, there are a total of 32 key switches 2.2. ...
A key switch matrix 5 consisting of
Connected to the output terminal of the modulated output signal OUT is the pace of a switching transistor 4 that turns on and off two infrared light emitting diodes 3, 3 in accordance with this signal OUT. The above 32 key switches 2, 2°...
is divided into four groups corresponding to the number of timing signals T1 to T4, and one or one of the four timing signals T, ~T, is input in parallel to the eight key switches 2 of each group. has been done. Then, when any one of the 32 key switches is pressed, %T1 to T4 will be activated.
One timing signal is inputted to the electronic circuit section 1 as a key human input signal, and one of 8 to 8 is inputted into the electronic circuit section l. 1-K for signal
When any one of a is input, the electronic circuit section l detects the pressed key switch 2 and outputs a specific OUT corresponding to the detected key switch. This modulated output signal OUT
The encoded signal which has been modulated by n1 by switching the transistor 4 is converted back to the original signal by two infrared light emitting diodes 3.3 and transmitted to a receiving circuit (not shown).

On the other hand, the receiving circuit side detects a coded signal from the received infrared light, demodulates it, and performs the above-mentioned specific function control.

By the way, in a conventional remote control transmitting circuit, a modulated output signal OUT output every time a key switch is pressed is configured as shown in FIG. 2 below. First, after a period of 88 has elapsed since the key switch was pressed, a start bit and an end bit are added, each having a period of 12a, and an encoded signal for one word continues for two words (r15). As shown in Figure 3, the coded signal for one word has a data structure in which a start bit of 11 levels is first entered, followed by 10 bits of data, and then ends with an end bit of w1t level. ing. Note that period a corresponds to a period of 1 bit. The reason why the period 8a is provided after the key switch is pressed is to wait for the oscillation frequency of the oscillation circuit built in the electronic circuit section 1 to become stable. The reason why the encoded signal for one word is output repeatedly twice is because the receiving circuit that receives the output from the transmitting circuit compares the first signal and the second signal, and the detected signal is correct. This is because it determines whether or not. However, in this method, function control is performed after detecting the second encoded signal, so the function control is performed on the receiving side after the key switch is pressed on the transmitting side, resulting in a long response time. There is.

Furthermore, conventionally, n is used when modulating the encoded signal.
The frequency of the carrier signal is set to 38 KHz. By the way, recently, for purposes such as energy saving, g
The number of k-lights using a high-frequency lighting method is increasing.

This system uses an inverter circuit to convert the 100V AC voltage into a high-frequency voltage, which is then supplied to the warning light via a transformer. When the light is turned on, the output voltage of the inverter circuit is increased, and the filament of the warning light is warmed by the stiffness, causing the warning light to discharge. In such a high frequency lighting system for warning lights, the frequency of the inverter circuit is set in the range of 30 to 44KH7. That is,
The frequency of the carrier signal is included within this frequency range. Moreover, the light component of the warning light contains 30 to 44KH.
Contains the infrared component of z. That is, by setting the frequency of the carrier signal used in the conventional remote control transmitting circuit to 38 KH2,
The carrier signal itself and the infrared light emitting diode 3,
The frequency of the light emitted from 3 is affected by the warning light driven by the inverter as described above. As a result, if a conventional remote control transmitting circuit is operated under the above-mentioned firelight, it may malfunction or even stop operating. In addition, in order to eliminate such drawbacks, the tuning circuit provided on the receiving circuit side should be
It must be configured to select only the remote control output, which complicates the circuit configuration.

[Purpose of the invention]

This invention was made in consideration of the above-mentioned circumstances, and its purpose is to shorten the response time from when a key switch is pressed until function control is performed on the receiving side. An object of the present invention is to provide a transmitting circuit for remote control that is not affected by fluorescent lights.

[Summary of the invention]

In the remote control transmitting circuit according to the present invention,
An inverted signal is formed for each bit signal of the encoded signal generated in response to the signal input from the key switch matrix cloud, and this inverted signal is added after that bit signal to generate the next bit signal for each bit signal. 71, so that the reception circuit side can judge whether the detection signal is good or bad for each pit.

Furthermore, in the remote control transmitting circuit according to the present invention, the frequency of carrier eye G is set outside the range of the driving frequency of the fluorescent lamp in order to avoid being affected by the fluorescent lamp driven by an inverter. This is how it was done.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a block diagram showing the configuration of a remote control transmitting circuit according to the present invention. In the figure, l is an integrated electronic circuit section, and outside of this electronic circuit section l there are 32 (7)-%--switches 2, 2 . A key switch matrix 5 consisting of... is provided. Also,
The electronic circuit section l includes an oscillation circuit 11. Brancher J2,
timing signal generation circuit 1B, key human power detection circuit 14,
A coded signal generation circuit 15, a bit signal inversion circuit J6, an output synthesis circuit 17, a modulation circuit 18, and a carrier signal generation circuit 19 are provided.

The oscillation circuit 11 is a self-biased amplifier circuit having a C-MOS inverter configuration, for example, which operates by connecting a ceramic oscillator 21 and two capacitors 22 and 23 to the external terminals of the electronic circuit N51. However, an oscillation output signal of 455 KHz is output. The starting output signal from the silkworm generating circuit 11 is frequency-divided by a frequency divider 12 rl,
Several divided signals with different frequencies are formed here. One or more frequency-divided signals formed by the divider 12 are supplied to a timing signal generation circuit 13.

The timing signal generation circuit 13 generates the four timing signals T, -T4 whose phases are different from each other from the branch signal1, and eight of these timing signals T1-T4 are divided into one signal.
It is supplied in parallel to each of the four sets of key switchers 2.

The electronic circuit section ll inputs the human power signal through each key switcher 2, and to 6 the key human power detection circuit 14
The detected signal is supplied to the encoded ID code generation circuit 15 by u1. Ru. The key human power detection circuit I4 checks which timing signal is being outputted from the timing signal generating circuit 13 when any of the key human power signals is detected. This is to determine which key switcher 2 in the key switch matrix 5 has been pressed. The encoded signal generation circuit 15 generates a 10-bit encoded signal in response to the detection signal of the key human power detection circuit 14, and this encoded signal is supplied to the bit signal inversion circuit 16.

The bit signal inversion circuit 16 is equipped with a signal inversion circuit, for example, an inverter, and forms an inversion signal for each bit signal of the encoded signal, and these inversion signals and each bit signal before inversion are output synthesized. The signal is supplied to the circuit 17. The output synthesis circuit 17 is supplied with the branch signal generated by the branch divider 12, and synthesizes the signal to be transmitted to the receiving circuit based on this frequency-divided signal and the output signal from the bit signal inversion circuit 16. do. The signal synthesized by the output synthesis circuit 17 is supplied to the modulation circuit IEn.

The carrier signal generating circuit 19 generates a 76 KHz carrier signal (modulated wave signal) having a frequency twice the conventional 38 KHz based on the frequency divided signal from the frequency divider 12, and this carrier signal is used to generate the modulated wave signal. It is supplied to circuit 18. The modulation circuit I8 modulates the signal l' synthesized by the output synthesis circuit 17 to 7 using the 76 KHz carrier signal. This modulated output signal 01JT turns on the infrared light emitting quads 3, 3, as in the case of FIG.

The switching transistor 40) is driven off.

In such a configuration, when one key switch 2 in the key switch matrix 5 is pressed, the key human force detection circuit 14 detects 1 to Ksf in the key human force signal to determine which key switch has been pressed. Next, the encoded signal +f generation circuit 15 generates a 0-bit encoded signal, which has the same number of bits as the conventional one, except for the start bit and end bit, in response to the detection signal from the key human input detection circuit 14. . Next, the bit signal inversion circuit 16 forms an inversion signal of each bit' signal of the 10-bit encoded signal. Furthermore, the output synthesis circuit I7 is connected to the bit signal inversion circuit 1.
Output @ from 6 and timing signal generation port F81B7I
Based on the timing signals of I and others, signals as shown in FIG. 5 are sequentially synthesized after a period of 8a has elapsed since the key switch was pressed. At this signal, the first (7) 1 hit)
(71 period (period a)) This 11-level star bit ST and this inverted signal ST continue, and in the subsequent 10-bit period, each bit signal D of the 10-bit encoded signal
I"""'DIO and the respective inverted signals -D, . continue alternately, and furthermore, in the period of the last 1 bit, the end pitch l-F, N of 11 lbel and this inverted signal EN are generated. Continuing, the signal synthesized by the output synthesis circuit 17 as described above is then modulated by a carrier signal having a frequency of 78 KHz in the modulation circuit 18. This modulated output signal OU
When T is input, the transistor 4 is turned on and turned off.The above-mentioned combined signal is converted by the infrared light emitting diode 3 and transmitted to the receiving circuit side. On the other hand, the receiving circuit side detects a signal from the received infrared light, demodulates the light, and performs specific function control.

Here, the signal transmitted from this embodiment circuit to the receiving circuit side is composed of one word, that is, 12 bits, but the start bit, end bit, and 10-bit encoded signal always have their original level and their inverted level. Since they are placed in pairs, when detecting a signal on the receiving circuit side, it is possible to judge on a bit-by-bit basis whether the signal has the correct power or not.

Moreover, since only one word's worth of signals needs to be transmitted to the receiving circuit, the response time from pressing the key switch in the transmitting circuit (1) to function control in the receiving circuit (1) is shorter than before. be able to.

In addition, in this example circuit, the frequency of the carrier signal is set to the conventional 38 KI (76 kHz, which is the borrowed value of Z), so as mentioned above, the frequency of the carrier signal is set to 4 kHz, which is 30 to 44 kHz. Therefore, it is obvious that it is possible to extend the original transmission distance and to prevent malfunctions and non-operations.

It goes without saying that the present invention is not limited to the above-mentioned embodiments, and that various modifications can be made. For example, in the above embodiment, the case where the encoding number 100 is 10 bits has been explained, but it may be any number of bits. Further, in the above embodiment, the frequency of the carrier signal is set to 76KH7.
Although we have explained the case where the setting is set to 1.1, this 71 basically sets the driving frequency range of the inverter-driven fluorescent lamp. Bye.

〔Effect of the invention〕

As explained above, according to the present invention, the response time from when the key switch is pressed to when function control is performed on the receiving side may be shortened, and the IS may be affected by the fluorescent light driven by the inverter. It is possible to provide a transmission circuit i'8 for remote control.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the general circuit configuration of a remote control transmitting circuit, Figures 2 and 3 are diagrams showing signals to explain conventional circuits, and Figure 4 is a diagram showing the conventional circuit. A block diagram showing a circuit configuration of an embodiment of
FIG. 5 is a diagram showing signals for explaining the circuit of the above embodiment. ! ...Electronic circuit section, 2...Key switch, 3...
Infrared & 1 element diode, 4...transistor, 5...
・Keysuitna matrix, lZ... oscillation circuit, 12
...Frequency divider, 13...Timing signal generation circuit, 1
4... Key human power detection circuit, 15... Encoded signal generation circuit, 16... Bit signal inversion circuit, 17... Output synthesis circuit, 18... Modulation circuit, 19... Carrier signal generation circuit.

Claims (1)

[Claims] In a transmitting circuit for remote control, which generates a coded signal consisting of multiple bits in response to a signal transmitted by a key switch matrix, modulates this signal with a carrier signal, and supplies the signal to an infrared light emitting diode. means for forming an inverted signal of each bit signal of the encoded signal and adding it to the bit; and means for setting the frequency of the carrier signal outside the range of the pivoting frequency of the fluorescent lamp driven by the inverter circuit. A transmitting circuit for remote control, which is characterized by the following: