JPH0549072A - Remote control receiver - Google Patents

Abstract

PURPOSE:To realize the remote control receiver with high noise immunity and no malfunction. CONSTITUTION:A control code reception section 2b receives and demodulates a ray transmitted through a carrier use optical filter F2 used to transmit a ray at a band of a wavelength lambda3 of a remote control ray SC A noise reception section 2a receives and demodulates a ray transmitted through an external ray use optical filter F1 used to transmit a ray at a band other than the wavelength lambda3 of the remote control ray SC. A gate section 9 transmits an output signal of the control code use reception section 2b and blocks the transmission of an output signal of the control code reception section 2b synchronously with the output signal of the noise use reception section 2a. Then a decode section 6 decodes an output signal of the gate section 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a receiver for a remote control used as an arrier). It should be noted that it specifically relates to an infrared remote control receiver.

Remote control devices (remote control transmission device and remote control reception device) using infrared rays are excellent and convenient because they can remotely control devices located at distant places. For example, it is an indispensable device in daily life when operating an AV (audio-video) device.

However, this convenient remote controller also has the disadvantage that it uses light rays as carriers. That is, the amount of extraneous light that is a noise source is extremely large. That is, the extraneous light gives noise to the remote control signal and causes malfunction of the remote control device.

On the other hand, the malfunction of the remote control device is an event that should not exist in order to ensure the safety of the remote control. That is, in some cases, it may cause fatal consequences such as damage to the controlled device and harm to human life.

Therefore, there is a demand for a remote control receiver that is robust against noise from external light.

[0006]

2. Description of the Related Art (1) Infrared remote control receiver When transmitting information using infrared rays as a communication carrier,
First, a high frequency signal (for example, 38 KHz) is modulated by the information to be transmitted, and then infrared rays are modulated by the modulated wave signal. Incidentally, it is general that the infrared modulation is performed by amplitude modulation. When transmitting the control code for the remote controller, the high frequency signal is also modulated by amplitude modulation.

That is, the high frequency signal is the second carrier for transmitting the control code.

FIG. 5 is a diagram for explaining an infrared remote controller and its receiving device, (a) is a block diagram of the remote control receiving device,
(B) is a waveform diagram showing an example of a control code signal.

A transmitter 1 in the figure is a device for transmitting a control code by using infrared rays as a carrier, and a receiver 2
Outputs a control output signal (decode output) D ₁ , D ₂ , D ₃ , ... From the control code by extracting the second carrier modulated from the received infrared ray and demodulating and decoding.

That is, in the light receiving portion 3 which is formed of a light receiving element such as a phototransistor, the received infrared rays are converted into electric signals. As a result, a high frequency signal modulated by the second carrier, that is, the control code is obtained.

Subsequently, the selective amplification section 4 selectively amplifies only the second carrier frequency, the demodulation / waveform shaping section 5 demodulates the control code, and the demodulated signal is shaped into a shape factor (sh
Shape to a waveform with a high arp factor).

Then, the control code signal is decoded by the decoding section 6 and the control output signals D ₁ , D ₂ , D ₃ , ... Corresponding to the control code are output.

Incidentally, FIG. 5 (b) shows an example of the demodulated and waveform-shaped control code signal, which is from time t ₁ to time t ₂ and time t _3.
To time t ₄ and the time period from t ₅ to time t ₆ is "L" level, the period of time t ₂ to time t ₃ and time t ₄ to time t ₅ is at "H" level.

(2) Effect of noise light and its countermeasure 1) Interference by external light As the infrared remote control device uses infrared rays as a communication carrier, interference by external light, that is, noise is unavoidable. In the natural world and human society, rays of light such as sunlight and illumination light overflow.

That is, as a result of the external light being received together by the light receiving section 3, necessary information, that is, a noise signal other than the control code signal is mixed. Then, the noise signal distorts the control code signal and gives an error to the decoding operation of the decoding section 6.

6A and 6B are diagrams for explaining the influence of external light on the infrared remote control device. FIG. 6A is a disturbance model diagram, FIG. 6B is a waveform diagram of a correct control code signal example, and FIG. It is a waveform diagram of an example of the control code signal.

FIG. 7 is a diagram for explaining the spectral distribution characteristics of a fluorescent lamp, where (a) is an example of a daylight color fluorescent lamp and (b) is an example of a white fluorescent lamp.

That is, as shown in FIG. 6A, the largest noise source for the infrared remote control device (transmitter 1 and receiver 2) is the fluorescent light of the fluorescent lamp 7. And the influence of flicker noise is particularly large. Further, the fluorescence of the fluorescent lamp 7 includes infrared spectral components in addition to visible light.

For example, the wavelength band used for the remote control device is a wavelength band of about λ = 900 nm. On the other hand, the fluorescent wavelength of the fluorescent lamp 7 covers the visible light wavelength band of approximately 400 nm to 700 nm, but the spectrum is also distributed in the wavelength band of 700 nm or more. (See Figure 7 (a) (b))

Then, these disturbances by the external light appear as shown in FIG. 6 (c) when observed with the control code signal. The correct control code signal is shown in FIG. 6 (b).

That is, the period from time t ₁₃ to time t _{14 and} the period from time t ₁₆ to time t ₁₇ must be "H" level correctly.

2) Countermeasures against noise light Therefore, in order to prevent such an error due to external light, the following countermeasures are taken.

A filter for transmitting only carriers, that is, infrared rays is provided in the light receiving portion of the remote control receiver. That is, unnecessary light other than the carrier is removed.

Use a strong control code. That is,
Use noise-resistant code.

The same control code is transmitted a plurality of times, and when the receiving device matches the codes at least twice or more, the code is confirmed and decoded. That is, a code containing noise is not adopted by determining a reproducible received output as a correct code.

[0026]

However, the conventional measures against noise light have the following problems.

Even if a filter which transmits only infrared rays is provided, the external light corresponding to the wavelength is directly received as noise light.

Even if a strong control code is used,
The effect of noise light cannot be completely eliminated. That is, it is less effective for strong noises exceeding the control code.

The method of transmitting the same control code a plurality of times requires a long time until the start of control, and is not suitable for real-time control. Moreover, the operator's operational feeling is annoying.

A technical object of the present invention is to eliminate the above-mentioned problems in a remote control device using a light beam and to enable a remote control receiver to remove noise, so that the remote control has strong noise resistance and no malfunction. It is to realize a receiving device.

[0031]

FIG. 1 is a diagram for explaining the principle of the present invention. (A) is a diagram showing the relationship between the spectrum of a light beam and the characteristics of an optical filter, and (b) is a diagram of a remote control receiver. Basic block diagrams, (c), (d), and (e) are waveform diagrams for explaining the operation of the remote control receiver.

The time axes in FIGS. 1 (c), (d) and (e) are the same time, (c) is the output signal of the receiver 2a, (d) is the output signal of the receiver 2d, and (e) Is an output signal of the gate unit 9.

The present invention is characterized in that the influence of extraneous light (noise light) is separately detected by a dedicated receiving unit, and the noise in the control code signal obtained by receiving and demodulating the carrier (light beam) is canceled. is there.

(1) Basic Configuration of Remote Control Receiving Device It is configured so as to have the following constituent requirements.

Optical filter F ₂ for a carrier that transmits a light beam in the wavelength λ ₃ band of the remote control light beam S _C

A control code receiving section 2b for receiving and demodulating the light beam transmitted through the carrier optical filter F _2.

Optical filter F ₁ for external light that transmits external light S _F other than the wavelength λ ₃ band of the remote control light beam S _C

A noise receiving section 2a for receiving and demodulating the light beam transmitted through the external light optical filter F ₁

A gate section that allows the output signal of the control code receiving section 2b to pass therethrough and blocks the output signal of the control code receiving section 2b from passing through in synchronization with the output signal of the noise receiving section 2a. 9

Decoding unit 6 for decoding the output signal of the gate unit 9

(2) Configuration of remote control receiving device using infrared rays The basic configuration of (1) is limited to infrared rays as a communication carrier.

That is, it is a device for transmitting and receiving a control code signal using infrared rays as a communication carrier, and is constructed by selecting the characteristics of the optical filters F ₂ and F ₁ as follows.

The transmission wavelength band of the carrier optical filter F ₂ is set to the wavelength λ ₃ band of the infrared ray S _C.

The transmission wavelength band of the optical filter F ₁ for extraneous light is set to a wavelength band in which the fluorescence spectrum S _F of the fluorescent lamp can be transmitted.

[0045]

(1) Remote control receiver of basic configuration The signal received and demodulated by the receiving section 2b via the optical filter F ₂ is a signal by the light beam for remote control of the wavelength λ ₃ , that is, a control code signal. However, for example, the signal shown in FIG.
(d) as exemplified in a noise signal 8b (time t _{25 ~} Time
t ₂₆ ) is included.

On the other hand, the signal received and demodulated by the receiving section 2a via the optical filter F ₁ is the signal by the external light S _F.
That is, it is a noise signal due to noise light, and the noise signal is, for example, the noise signal 8a (time t
It appears like ₂₅ -time t ₂₆ ).

By the way, the most harmful noise in a remote control receiver using light rays is flicker noise that appears in the same cycle as the control code signal. When the flicker noise is generated by the same light source, the flicker noise is generated with the same probability over almost the entire emission band. That is, there is simultaneity.

Therefore, as the gate signal of the gate section 9,
By using the output signal of the noise receiving unit 2a, that is, the noise signal 8a, the output signal of the control code receiving unit 2b, that is, the noise signal 8b included in the control code signal can be blocked / removed. That is, as illustrated in FIG. 1 (e), the noise signal 8b that existed during the time period from t _{25 ~} time t ₂₆ can be removed.

As a result, the decoding unit 6 can decode the control code signal having no noise signal,
Erroneous operation caused by external light _SF as a noise source is eliminated.

(2) Configuration of Remote Control Receiving Device Using Infrared Light This remote control receiving device is a remote control receiving device in which light rays, that is, carriers are limited to infrared rays.

The largest noise source when infrared rays are used as a carrier is fluorescence of a fluorescent lamp and its flicker noise. However, the flicker noise is generated with almost the same probability over the entire fluorescent band of the fluorescent lamp. That is, there is simultaneity.

Therefore, the noise signal 8b in the control code signal received and demodulated by the receiver 2b via the optical filter F ₂
Can be removed by the gate unit 9 using the noise signal 8a received and demodulated by the receiving unit 2a via the optical filter F ₁ as a gate signal.

As a result, the decoding section 6 can decode the control code signal having no noise signal,
The malfunction of the remote control receiver is eliminated.

[0054]

EXAMPLES Next, practical examples of how the remote control receiver according to the present invention can be embodied will be described.

(1) Configuration FIG. 2 is a block diagram for explaining the configuration of the remote control receiver of the embodiment.

The remote control receiver of this embodiment is different from the conventional infrared remote control receiver shown in FIG. 5 in that it has two optical filters F ₁₁ and F ₁₂ which are a filter for noise light and a filter for carrier. In addition, it has a two-system receiving section, a control code receiving section and a noise receiving section, and RS F / F (reset-set flip-flo) as a gate section.
p) that it has 9a.

That is, the two-system receiving section is composed of a light receiving section 3a, a selective amplifying section 4a and a demodulating / waveform shaping section 5a, and a light receiving section 3b, a selective amplifying section 4b and a demodulating / waveform shaping section 5b.
The former is a receiving unit for carrier reception and the latter is a receiving unit for noise light reception.

That is, the RS F / F 9a set by the control code signal output from the carrier receiving section (light receiving section 3a, selective amplifying section 4a, demodulating / waveform shaping section 5a) is received by the noise receiving section (light receiving section). This is a mechanism for removing the noise signal contained in the control code signal by resetting with the noise signal output from the 3b, the selective amplification section 4b, and the demodulation / waveform shaping section 5b). The carrier is infrared light with λ≈900 nm.

FIG. 3 is a diagram showing the light transmittance characteristics of the optical filter used for receiving the carrier. That is, FIG.
This is the characteristic of the optical filter F ₁₁ of.

The characteristics of the optical filter illustrated in FIG. 3 are "S Alloy A-126" manufactured by Nippon Steel Chemical Co., Ltd.
Is the light transmittance characteristics of the optical filter, and the thickness of the optical filter is 3.0
The color tone in mm is color No. BA-91696.

That is, 65% or more of infrared rays having a wavelength λ≈800 nm or more are transmitted, but light having a wavelength shorter than the wavelength is hardly transmitted.

On the other hand, an optical filter used for receiving noise
As F ₁₂ , an infrared filter generally used in optical equipment was used, and an infrared filter having a cutoff wavelength λ _c ≈500 nm was used. That is, the infrared rays of the carrier are not transmitted.

(2) Operation FIG. 4 is a view for explaining the operation of the receiving apparatus of the embodiment, (a)
~ (D) is a waveform chart of each part, and (e) is a truth chart for explaining the operation of RS F / F.

4A includes a noise signal output from the noise receiver, FIG. 4B includes a control code signal transmitted from the remote control transmitter, and FIG. 4C includes noise output from the carrier receiver. Control code signal, (d) shows the output signal of RS F / F 9a. Further, the logic of the remote control receiver of the present embodiment operates at low-active, and the time axes of (a) to (d) are the same time.

[0065] 1) Example of a control code signal which indicates the transmitted control code signal reference (FIG. 4 (b)) FIG. 4 (b), the period and the time of the time t _{33 ~} time t ₃₆ t _{41 ~} time t ₄₄ Period is "L"
It is a level.

It should be noted that the infrared rays transmitted from the infrared remote control transmitter and modulated by the control code signal do not contain any noise. All noise is given as extraneous light.

2) Noise signal received by the noise receiver (see FIG. 4 (a)) The noise signal illustrated in FIG. 4 (a) is a noise component given to the remote control receiver by the external light and is an optical noise. Is a signal that is captured by an electric signal. That is, it is the noise signal captured by the noise receiver.

The period and time from time t ₃₁ to time t ₃₂
period t ₃₄ ~ time t _35, the period of time t _{3 7} ~ time t _38, the period of time t ₃₉ ~ time t _40, the period from time t ₄₂ ~ time t _{4 3} is a "L" level.

3) Control code signal received by carrier receiver (see FIG. 4 (c)) Examples of the received control code signal shown in FIG. 4 (c) include the correct control code signal component of 1) above. At time t ₃₁ ~
Period and the time period of t _{37 ~} time t ₃₈ at time t _32, an "L" level for the period of time t _{39 ~} time t _40, which is the noise signal component.

[0070] Incidentally, as shown in FIG. 4 (a), the time t ₃₄ ~
Although for even the noise signal period of time and the time t _{39 ~} time t ₄₀ at time t ₃₅ is present, because for that period is control code signal is also active, the noise signal components do not give apparently affected.

4) Operation of noise gate (RS F / F output signal: see FIG. 4 (d)) Noise gate, that is, RS F / F 9a shown in FIG.
Operates according to the truth diagram in Fig. 4 (e). still,
The output signal of the carrier receiver shown in Fig. 4 (c) is set
Input as the (S) signal, and the output signal of the noise receiver shown in FIG. 4 (a) is input as the reset (R) signal.

Next, the operation of the RS F / F 9a will be described in chronological order. RS F / in the period before time t ₃₁
It is assumed that the (Q) output of F 9a is at "H" level as shown in Fig. 4 (d).

[0073] Period The period from time t _{31 ~} time t ₃₂ is set (S) input is "L" level, the reset (R) input is also at "L" level. Therefore, RS F /
The (Q) output of F 9a maintains its previous state (Qn). Therefore, it is the "H" level.

Period from time t ₃₂ to time t ₃₃ During this period, the set (S) input is at "H" level and the reset (R) input is also at "H" level. Therefore, RS F /
The (Q) output of F 9a becomes "H" level.

Period from time t ₃₃ to time t ₃₄ During this period, the set (S) input is at "L" level and the reset (R) input is at "H" level. Therefore, RS F /
The (Q) output of F 9a becomes "L" level.

[0076] period of time t _{34 ~} time t ₃₅ during this period is a set (S) input is "L" level, the reset (R) input is also at the "L" level. Therefore, RS F /
The (Q) output of F 9a maintains its previous state (Qn). Therefore, it becomes "L" level.

Period from time t ₃₅ to time t ₃₆ During this period, the set (S) input is at "L" level and the reset (R) input is at "H" level. Therefore, RS F /
The (Q) output of F 9a becomes "L" level.

Period from Time t ₃₆ to Time t ₃₇ During this period, the set (S) input is at "H" level and the reset (R) input is also at "H" level. Therefore, RS F /
The (Q) output of F 9a becomes "H" level.

After that, the same operation is performed after time t ₃₇ .

That is, as shown in FIG. 4 (d), RS F /
The noise signal component can be completely removed from the output signal of F9a. Therefore, the decoding unit 6 shown in FIG. 2 can perform decoding work without error.

[0081]

As described above, according to the remote control receiving device of the present invention, noise due to external light can be removed by the remote control receiving device. Therefore, it is possible to realize a remote control receiving device having strong noise resistance and no malfunction. As a result, the reliability of the remote control device using light rays can be significantly increased.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the principle of the present invention, in which (a) is a diagram showing the relationship between the spectrum of a light beam and the characteristics of an optical filter;
(b) is a basic block diagram of the remote control receiver, (c) (d) (e)
FIG. 7 is a waveform diagram for explaining the operation of the remote control receiver.

FIG. 2 is a block diagram illustrating a configuration of a remote control receiving device according to an embodiment.

FIG. 3 is a diagram showing a light transmittance characteristic of an optical filter used for receiving a carrier in an example.

FIG. 4 is a diagram for explaining the operation of the receiving device of the embodiment, (a)
~ (D) is a waveform chart of each part, and (e) is a truth chart for explaining the operation of RS F / F.

5A and 5B are diagrams illustrating an infrared remote controller and a receiver thereof, FIG. 5A is a block diagram of the remote controller receiver, and FIG. 5B is a waveform diagram showing an example of a control code signal.

FIG. 6 is a diagram for explaining the influence of external light on the infrared remote control device, where (a) is a disturbance model diagram, (b) is a waveform diagram of a correct control code signal example, and (c) is a control code containing noise. It is a waveform diagram of an example of a signal.

7A and 7B are diagrams illustrating spectral distribution characteristics of a fluorescent lamp, in which FIG. 7A is an example of a daylight fluorescent lamp, and FIG. 7B is an example of a white fluorescent lamp.

[Explanation of symbols]

1 (infrared remote controller) transmitter 2 (infrared remote controller) receiver 2a, 2b receiver 3,3a, 3b light receiver 4,4a, 4b selective amplifier 5,5a, 5b demodulator / waveform shaper 6 decoder 7 fluorescent lamp 8 _-1 , 8, _-2 noise 8a, 8b noise 9 Gate 9a RS F / F (reset-set flip-flop) D ₁ , D ₂ , D ₃ , ... Decode output _SF External light (fluorescent lamp) Spectral spectrum of S _C Ray spectrum for remote control (infrared) F ₁ Optical filter λ ₁ Optical filter F ₁ cutoff wavelength F ₂ Optical filter λ ₂ Optical filter F ₂ cutoff wavelength λ ₃ Remote control light ray (infrared) Wavelength F ₁₁ , F ₁₂ Optical filter F Optical filter

Claims (2)

[Claims] 1. In a system for transmitting and receiving a control code signal by using a light beam as a communication carrier and remote-controlling a controlled object, the control code signal transmitted by the light beam is used. Reception / demodulation /
Decode a remote control receiver for (decode-), an optical filter for carrier to transmit light of a wavelength (lambda ₃₎ band of the remote control light _{(S C) (F 2)} , an optical filter for carrier (F ₂ ) Is received by the control code for receiving and demodulating the light beam that has passed through (2), and external light other than the wavelength (λ ₃ ) band of the remote control light beam (S _C ).
(S _F ) an optical filter for external light that transmits (F ₁ ), a receiving unit (2a) for noise that receives and demodulates a light beam that has passed through the optical filter for external light (F ₁ ), and the control While passing the output signal of the code receiving unit (2b), in synchronization with the output signal of the noise receiving unit (2a) the gate unit for blocking the passage of the output signal of the control code receiving unit (2b) ( 9) and a decoding unit for decoding the output signal of the gate unit (9)
(6) A remote control receiving device comprising: 2. The remote control receiver according to claim 1, which is a device for transmitting and receiving a control code signal by using infrared rays as a communication carrier, the transmission wavelength of a carrier optical filter (F ₂ ). Band with infrared
Wavelength (λ ₃ ) band of (S _C ), optical filter for external light (F ₁ )
The remote control receiver is characterized in that the transmission wavelength band of is configured as a wavelength band through which the fluorescence spectrum ( _SF ) of a fluorescent lamp can be transmitted.