JP3068072U - Electrical equipment - Google Patents

Abstract

(57) [Problem] To reduce the scale of hardware for performing signal processing of an output of a photoelectric conversion element. A band-pass filter for extracting a signal component in the vicinity of the frequency of a carrier signal from an output of a photoelectric conversion element, a detection unit for extracting an envelope signal of an output of the band-pass filter, and a detection unit. Control means 26 for controlling the operation state in accordance with the control data indicated by the envelope signal. The detection means 32 and the control means 26 are constituted by the microcomputer 7 executing software stored in advance.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to an electric device that receives an optical signal indicating data depending on the presence or absence of a carrier signal, and more specifically, executes a predetermined software to execute a detection means for extracting an envelope signal from an output of a photoelectric conversion element. It relates to electrical equipment composed of microcomputers.

[0002]

[Prior art]

 Some conventional home electric appliances such as televisions and video cassette recorders can control the operation using a remote controller that transmits a remote control signal (hereinafter, referred to as a remote control signal) by infrared light. Something is possible. In such an apparatus, a remote control signal emitted from a remote controller passes through a light receiving window provided on a front panel of an electric device to be controlled, and corresponds to the light receiving window inside a housing of the electric device. It reaches the remote control receiver provided at the position.

[0003] A conventional remote control light receiver includes a photoelectric conversion element that converts an optical signal into an electric signal, a signal processing circuit that demodulates a remote control signal by processing the converted electric signal, and a frame that accommodates the signal. It is composed of

FIG. 5 shows an electrical configuration of a control block including the above-described signal processing circuit. That is, the signal sent from the photoelectric conversion element 6 is amplified by the amplifier 22 and then the level is fixed by the limiter 23. The signal whose level has been stabilized is subjected to removal of unnecessary signal components by a band-pass filter 24 that passes the frequency of the carrier signal of the remote control signal (for example, 38 kHz), and then enveloped by a detection circuit 25. It is detected. The signal detected by the envelope detection is constituted by a microcomputer and guided to a control means 26 for controlling the apparatus (referred to as a first conventional technique).

[0005] Furthermore, devices relating to signal processing performed by the above-described signal processing circuit are being actively devised. For example, an infrared light receiving device proposed in Japanese Utility Model Laid-Open No. 4-38150 has a photoelectric conversion element that receives infrared light connected to an input side of an input amplifier, and a mechanical resonance phenomenon is generated on the output side of the input amplifier. The configuration is characterized by connecting a used bandpass filter (this is referred to as a second conventional technique).

A remote control receiver proposed in Japanese Utility Model Laid-Open Publication No. 1-126787 discloses a photo-amplifier that receives a remote-control signal and performs photoelectric conversion, and decodes a code signal from the photo-amplifier to transmit a control signal. A relay device is interposed between the processor and the processing unit, and in this relay device, a predetermined process is performed on the code signal of the photoamplifier (third related art).

Further, an infrared remote control data receiving circuit and a control method thereof proposed in Japanese Patent Application Laid-Open No. 7-38975 are disclosed in which a pulse signal of remote control data is stored in a shift register, and a divided clock timing is obtained. By reading the remote control data stored in the shift register, the load on the CPU used for reading the remote control data can be reduced and the processing capability of the CPU can be improved. (Referred to as a fourth prior art).

[0008]

[Problems to be solved by the invention]

 By the way, the electric device capable of receiving the remote control signal by the infrared light constitutes the control means 26 separately from the signal processing circuit 21 for processing the output signal from the photoelectric conversion element 6 as described above. Microcomputer 27 is provided. Further, in recent years, the microcomputer 27 has become inexpensive even in the case of an element having an extremely high processing speed.

[0009] In consideration of the above, the first conventional technique has the following problems. In other words, the microcomputer 27 has the ability to process a part of the processing of the signal processing circuit 21 in parallel with the operation for control, even in the case of inexpensive elements. ing. However, in the first prior art, as shown in FIG. 5, an envelope signal is extracted from the output of the photoelectric conversion element 6 by using dedicated hardware such as a signal processing circuit 21. For this reason, there has been a problem that the scale of the hardware is increased and the manufacturing cost is unnecessarily increased. Further, the second to fourth prior arts are difficult to apply from the viewpoint of reducing hardware.

The present invention has been made in order to solve the above-mentioned problem, and an object of the present invention is to provide a microcomputer which executes detection software for extracting an envelope signal from an output signal of a photoelectric conversion element by executing software stored in advance. An object of the present invention is to provide an electric device which can reduce the scale of hardware for performing signal processing of an output of a photoelectric conversion element.

In addition to the above object, an envelope signal is extracted based on an interval at which an output level of a band-pass filter that extracts only a signal of a specific frequency component from an output signal of the photoelectric conversion element changes. An object of the present invention is to provide an electric device that can simplify the configuration of a detection unit that extracts a line signal.

[0012]

[Means for Solving the Problems]

 In order to solve the above-described problem, an electric device according to the present invention includes: a photoelectric conversion element that receives an optical signal indicating control data depending on the presence or absence of a carrier signal; A band-pass filter for extracting a signal component, detection means for extracting an envelope signal of the output of the band-pass filter, and control means for controlling an operation state according to control data indicated by the envelope signal extracted by the detection means. And the detection means and the control means are constituted by a microcomputer executing software stored in advance.

That is, the signal processing of the output of the photoelectric conversion element is performed by the band-pass filter and the detecting means. On the other hand, since the detection means is constituted by a microcomputer executing software stored in advance, dedicated hardware for constituting the detection means is not required. Therefore, the dedicated hardware for signal processing of the output of the photoelectric conversion element is only a bandpass filter.

[0014] In addition to the above configuration, the detection means may be configured such that the carrier signal is output during a period in which the level of the output of the band-pass filter changes is shorter than a predetermined reference interval. The envelope signal is extracted by judging that there is, and judging that there is no carrier signal in a period in which the output level change interval of the bandpass filter is longer than the judgment reference interval.

That is, the detecting means only detects the interval at which the output level of the band-pass filter changes, and compares the detected interval with the determination reference interval, and converts the envelope signal from the output of the band-pass filter. Can be taken out.

[0016]

[Embodiment of the invention]

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 3 is a perspective view showing a configuration of the electric device according to the present invention, and FIG. 4 is a cross-sectional view showing a cross section taken along a cutting line AA in FIG.

In FIG. 1, reference numeral 1 denotes a thin rectangular parallelepiped electrical device housing. Reference numeral 2 denotes a front panel that forms the front surface of the housing 1 and has a U-shaped cross section when viewed from above. The front panel 2 is provided with a light receiving window 2a.

In the light receiving window 2a, one end of a light guide 3 for receiving and guiding an optical signal is fitted and attached from the back side of the front panel 2, and an end face of the one end exposed to the light receiving window 2a. 3 a corresponds to the interface of the front panel 2. Further, a convex lens structure such as a Fresnel lens is formed on the end face 3a by a microprism, so that the light receiving angle range of the optical signal is expanded.

The light guide 3 receives an optical signal arriving from the front side of the front panel 2 on the end face 3 a and guides the light signal to the output end face 3 b facing the bottom face of the housing by a two-stage bending structure. Specifically, the optical signal received on the end face 3a reaches the end face 3b by repeating the straight traveling inside the medium of the light guide 3 and the reflection inside the interface. Further, by forming a concave lens structure on the end face 3b, an optical signal output from the end face 3b is converged in a certain angle range.

On the other hand, 4 is a circuit board installed in parallel with the bottom surface of the housing 1, and the circuit board 4 is mounted on the mounting surface by locking members 5, 5 mounted on the back bottom of the front panel 2. At a position separated from the front panel 2 by an appropriate dimension. Further, at the position corresponding to the end face 3b on the mounting surface of the circuit board 4, the photoelectric conversion element 6 for receiving an optical signal is arranged such that the directivity direction substantially matches the normal direction of the mounting surface of the circuit board 4. Attached to. The circuit board 4 is provided with a signal processing circuit (not shown) for processing the signal of the photoelectric conversion element 6 and a microcomputer 7 integrated into one chip. An output signal of the photoelectric conversion element 6 is guided to a signal processing circuit by a wiring pattern of the circuit board 4, and an output of the signal processing circuit is guided to a microcomputer 7.

With the above configuration, an optical signal arriving from the front side of the front panel 2 is collected by the convex lens structure on the end face 3 a of the light guide 3. In addition, since the light is converged by the concave lens structure of the end face 3b, attenuation caused in the process of propagating through the light guide 3 is compensated. Therefore, the optical signal received on the end face 3a reaches the photoelectric conversion element 6 as a signal of a practicable level.

The optical signal is infrared light transmitted from a remote controller (not shown), and is a signal indicating control data depending on the presence or absence of a carrier signal. Further, the frequency of the carrier signal is about 38 KHz in the present embodiment.

FIG. 1 is a block diagram showing an electric configuration of an embodiment of the electric device according to the present invention. In FIG. 1, only blocks for performing control based on an optical signal are shown. I have. Blocks having the same configuration as the prior art shown in FIG. 5 are assigned the same reference numerals as those in FIG.

In the present embodiment, the photoelectric conversion element 6 is a pin photodiode, and converts a received optical signal into an electric signal. The amplifier 22 is a block that amplifies the signal output from the photoelectric conversion element 6 and sends the amplified signal to the limiter 23. The limiter 23 is a block for limiting the level of the signal amplified by the amplifier 22 to a predetermined level, and sends out the level-limited signal to the bandpass filter 24. The band pass filter 24 is a filter that passes only signal components near the frequency (38 KHz) of the carrier signal in the optical signal and removes other frequency components.

The detection means 32 to which the output of the band-pass filter 24 is guided is a block for extracting an envelope signal of the signal transmitted from the band-pass filter 24. That is, it is determined that there is a carrier signal during a period in which the interval at which the output level of the bandpass filter 24 changes is shorter than a predetermined reference interval (30 μS in the present embodiment). The envelope signal is extracted by determining that there is no carrier signal in a period in which the output level of the band-pass filter 24 changes longer than the determination reference interval. Then, the extracted envelope signal 72 is sent to the control means 26.

The control means 26 is a block for controlling main operations as an electric device. Therefore, when the envelope signal 72 is transmitted from the detection means 32, the control data indicated by the transmitted envelope signal 72 is extracted. Then, the operation state of the electric device is controlled according to the extracted control data.

Each of the amplifier 22, the limiter 23, and the band-pass filter 24 is a block configured by a signal processing circuit 31, which is dedicated hardware. Each of the detection means 32 and the control means 26 is a single-chip element, and is a block constituted by the microcomputer 7 executing software stored in advance.

FIG. 2 is an explanatory diagram showing waveforms of main signals in the present embodiment. The operation of the embodiment will be described with reference to FIG.

The optical signal received by the photoelectric conversion element 6 is a signal indicating control data depending on the presence or absence of a 38 KHz carrier signal. Therefore, when the output of the band-pass filter 24 is viewed from the detection means 32 constituted by the microcomputer 7, the output of the band-pass filter 24 is at L level during the periods t11, t13,. The signal changes to the H level, and the output of the bandpass filter 24 is at the L level during the periods t12, t14,.

In the periods t11, t13,... Where the carrier signal is present, the interval at which the output level of the band-pass filter 24 changes is about 13 μS because the frequency of the carrier signal is 38 KHz. That is, in the periods t11, t13,..., The output of the bandpass filter 24 changes from the L level to the H level or from the H level to the L level at intervals of about 13 μS.

The output of the band-pass filter 24 is the signal described above. For this reason, the detection means 32 determines that there is a carrier signal in the periods t11, t13,... Where the interval at which the output level of the bandpass filter 24 changes is shorter than 30 μS (determination reference interval). , During which the output level of the band-pass filter 24 changes longer than 30 μS (determination reference interval), it is determined that there is no carrier signal.

More specifically, when the optical signal is not transmitted from the remote controller (before the time T1), the output of the band-pass filter 24 is maintained at the L level exceeding 30 μS. It is determined that there is no carrier signal, and the level of the envelope signal 72 transmitted to the control means 26 is set to L level.

When the optical signal is transmitted from the remote controller at time T 1, a signal that changes between the H level and the L level appears at an interval of about 13 μS in the output of the bandpass filter 24. Therefore, upon detecting the rising edge 41, the detection means 32 determines the time T1 at which the rising edge 41 is detected as the start time of the transmission of the carrier signal. When the falling edge 42 is detected, it is determined whether a rising edge appears within 30 μS. In this case, since the rising edge 43 appears within 30 μS (period t1 is about 13 μS), the detection means 32 determines that the period in which the carrier signal exists is continued.

Hereinafter, every time a falling edge appears, the same operation is repeated. Then, when the falling edge 45 appears, the detection means 32 similarly determines whether or not the rising edge appears within 30 μS (period t3). At this time, no rising edge appears within 30 μS. Therefore, the detecting means 32 determines the time T2 at which the falling edge 45 is detected as the time at which the carrier signal ends.

Similarly, the detection means 32 determines the time T3 at which the rising edge 46 appears as the start time of the carrier signal, and determines the time T4 at which the falling edge 47 appears as the time at which the carrier signal ends. Is determined.

The detection means 32 performs the above-described determination operation on the output of the band-pass filter 24. In parallel with this determination operation, the detection means 32 changes the level of the envelope signal 72 from the L level to the H level at a time T5 delayed by 30 μS (period t4) from the time T1. At time T6, which is 30 μS (period t3) later than time T2, the level of the envelope signal 72 is changed from H level to L level. At time T7, which is 30 μS later than time T3, the level of the envelope signal 72 is changed from L level to H level. At time T8, which is 30 μS later than time T4, the level of the envelope signal 72 is changed from H level to L level.

That is, the detection means 32 sends the envelope signal 72 extracted from the output of the band-pass filter 24 to the control means 26 with a delay of 30 μS, which is the determination reference interval, from the output of the band-pass filter 24. Send out.

The control means 26 to which the above-mentioned envelope signal 72 is given extracts control data indicated by the envelope signal 72. Then, by controlling the operation of a circuit unit (not shown) according to the extracted control data, the operation state of the electric device is set to the operation state according to the instruction of the remote controller.

Note that the present invention is not limited to the above embodiment, and the case where the frequency of the carrier signal is set to 38 KHz has been described. However, the frequency can be set to an arbitrary frequency such as 35 KHz. Has become.

The case where the determination reference interval as the determination reference of the presence or absence of the carrier signal is set to 30 μS has been described. However, the determination reference interval can be set to an arbitrary value longer than の of the period of the carrier signal. ing.

[0041]

[Effect of the invention]

 As described above, the electric device according to the present invention includes a photoelectric conversion element that receives an optical signal indicating control data depending on the presence or absence of a carrier signal, and a signal near the frequency of the carrier signal from the output of the photoelectric conversion element. A band-pass filter for extracting components, a detecting means for extracting an envelope signal of the output of the band-pass filter, and a control means for controlling an operation state according to control data indicated by the envelope signal extracted by the detecting means, The detection means and the control means are constituted by a microcomputer executing software stored in advance. Therefore, the dedicated hardware for signal processing of the output of the photoelectric conversion element is only a bandpass filter, so that it is possible to reduce the scale of the hardware for signal processing of the output of the photoelectric conversion element. ing.

Further, the detecting means determines that the carrier signal is present during a period in which the interval of the output level change of the band-pass filter is shorter than a predetermined reference interval which is a predetermined interval. It is configured that the envelope signal is extracted by determining that the carrier signal does not exist during a period in which the output level of the band-pass filter changes longer than the determination reference interval. Therefore, the detection means can extract the envelope signal from the output of the bandpass filter only by extracting the interval at which the output level of the bandpass filter changes and comparing the extracted interval with the determination reference interval. Therefore, it is possible to simplify the configuration of the detecting means for extracting the envelope signal.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electrical configuration of an embodiment of an electric device according to the present invention.

FIG. 2 is an explanatory diagram illustrating waveforms of main signals according to the embodiment.

FIG. 3 is a perspective view showing a configuration of the electric device according to the present invention.

FIG. 4 is a cross-sectional view showing a cross section taken along a cutting line AA in FIG. 3;

FIG. 5 is a block diagram showing an electrical configuration of the related art.

[Explanation of symbols]

 Reference Signs List 6 photoelectric conversion element 7 microcomputer 24 band pass filter 26 control means 31 signal processing circuit by dedicated hardware 32 detection means 71 output of band pass filter 72 envelope signal t3 determination reference interval t11, t13,. Existence period t12, t14, ... period without carrier signal

Continued on the front page (51) Int.Cl. ⁷ Identification code FI H04B 10/135 10/13 10/12 H04Q 9/00 311 341

Claims (2)

[Utility model registration claims] A photoelectric conversion element for receiving an optical signal indicating control data according to the presence or absence of a carrier signal; a band-pass filter for extracting a signal component near a frequency of the carrier signal from an output of the photoelectric conversion element; Detection means for extracting an envelope signal of the output of the pass filter, and control means for controlling an operation state according to control data indicated by the envelope signal extracted by the detection means, wherein the detection means and the control means, An electric device comprising a microcomputer that executes software stored in advance. 2. The method according to claim 1, wherein the detecting unit determines that the carrier signal is present in a period in which an interval at which the output level of the band-pass filter changes is shorter than a predetermined reference interval. 2. The electric device according to claim 1, wherein the envelope signal is extracted by determining that there is no carrier signal in a period in which the output level of the pass filter changes longer than the determination reference interval. 3. .