KR970000926Y1 - Tape terminal detection circuit - Google Patents
Tape terminal detection circuit Download PDFInfo
- Publication number
- KR970000926Y1 KR970000926Y1 KR2019910017305U KR910017305U KR970000926Y1 KR 970000926 Y1 KR970000926 Y1 KR 970000926Y1 KR 2019910017305 U KR2019910017305 U KR 2019910017305U KR 910017305 U KR910017305 U KR 910017305U KR 970000926 Y1 KR970000926 Y1 KR 970000926Y1
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- KR
- South Korea
- Prior art keywords
- tape
- light emitting
- output
- voltage
- detection circuit
- Prior art date
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Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
- G11B15/02—Control of operating function, e.g. switching from recording to reproducing
- G11B15/05—Control of operating function, e.g. switching from recording to reproducing by sensing features present on or derived from record carrier or container
- G11B15/06—Control of operating function, e.g. switching from recording to reproducing by sensing features present on or derived from record carrier or container by sensing auxiliary features on record carriers or containers, e.g. to stop machine near the end of a tape
- G11B15/08—Control of operating function, e.g. switching from recording to reproducing by sensing features present on or derived from record carrier or container by sensing auxiliary features on record carriers or containers, e.g. to stop machine near the end of a tape by photoelectric sensing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B2220/00—Record carriers by type
- G11B2220/90—Tape-like record carriers
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- Electronic Switches (AREA)
- Geophysics And Detection Of Objects (AREA)
Abstract
내용없음.None.
Description
제1도는 종래 기술에 따른 테이프 종단 검출회로도1 is a tape termination detection circuit according to the prior art
제2도는 본 고안에 따른 테이프 종단 검출회로도.2 is a tape termination detection circuit according to the present invention.
제3도는 제2도 각부의 신호 파형도이다.3 is a signal waveform diagram of each part of FIG.
* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings
11 : 발진기 10 : 테이프11: oscillator 10: tape
13 : OP 앰프 14 : 대역통과 필터13: OP Amplifier 14: Bandpass Filter
20 : 비교기20: comparator
본 고안은 카세트 테이프 레코더의 테이프 종단검출회로에 관한 것으로서 특히 외부의 광원, 반사등에 의한 테이프 종단의 오검출을 방지하기 위한 테이프종단 검출회로에 관한 것이다.The present invention relates to a tape end detection circuit of a cassette tape recorder, and more particularly, to a tape end detection circuit for preventing erroneous detection of a tape end by an external light source or a reflection.
카세트 테이프 레코더에서 일반적으로 사용되고 있는 테이프 종단검출방법은 제1도에 도시한 바와같은 회로를 사용하고 있는바, 테이프종단을 검출하기 위한 센서(1) 즉, 발광다이오드(1A)와 포토트랜지스터(1B)로 구성된 센서의 발광다이오드(1A)에 일정 전류를 흘려줌으로써 발광다이오드(1A)는 항상 점등된 상태를 유지한다.The tape end detection method generally used in a cassette tape recorder uses a circuit as shown in FIG. 1. The sensor 1 for detecting the end of tape, that is, the light emitting diode 1A and the phototransistor 1B. By supplying a constant current to the light emitting diode 1A of the sensor composed of), the light emitting diode 1A is always kept lit.
이때 테이프의 종단부분인 투명부분이 종단센서(1)위치 다시말하면, 발광다이오드(1A)와 포토트랜지스터(1B)사이에 오면 포토트랜지스터(1B)가 턴온되어 그의 콜렉터에서는 수광량에 비례하는 전류가 흐르게되고, 검출부(2)에서는 포토트랜지스터(1B)의 콜렉터 전류를 전압으로 환산하여 이전압을 기준전압과 비교하여 검출결과를 출력하게 된다.In this case, when the transparent portion, which is the end of the tape, is positioned between the end sensor 1, that is, between the light emitting diode 1A and the phototransistor 1B, the phototransistor 1B is turned on so that a current proportional to the amount of received light flows in the collector. The detector 2 converts the collector current of the phototransistor 1B into a voltage, compares this voltage with a reference voltage, and outputs a detection result.
그러나, 이러한 종래의 회로는 포토트랜지스터 측으로 외부의 광원이나 발광다이오드의 불빛이 카세트레코더와 본체 또는 테이프면에 반사된 빛이 수광될 경우, 입사되는 광량이 실제 테이프 종단부분을 투과한 광량정도가 되어 검출부가 오출력을 발생하는 문제점이 있었다.However, in the conventional circuit, when light from an external light source or a light emitting diode is reflected on the cassette recorder, the main body, or the tape surface to the phototransistor, the incident light amount is about the amount of light transmitted through the end portion of the tape. There was a problem that the detector generates an incorrect output.
따라서, 본 고안은 이러한 사정을 감안하여 안출한 것으로서, 발광부를 일정주파수로 온/오프시켜 검출부에는 발광부의 온/오프주파수와 동일 주파수를 중심주파수로하는 대역필터를 사용함으로써 타광원에 의한 오검출과 반사에 의한 오검출을 방지하기 위한 테이프 종단검출 회로를 제공하는데 그 목적이 있다.Accordingly, the present invention has been devised in view of such circumstances, and the false detection by other light sources is achieved by using a band filter having the light emitting part on / off at a constant frequency and using a band filter having the same frequency as the on / off frequency of the light emitting part. It is an object of the present invention to provide a tape termination detection circuit for preventing false detection due to excessive reflection.
이러한 목적을 달성하기 위한 본 고안은 빛을 발산하는 발광다이오드와, 상기의 발광다이오드에서 발생된 광선은 수광하여 전류신호를 발생하는 포토트랜지스터로된 테이프 종단검출센서를 구비한 테이프 종단검출 회로로서, 이는 상기의 발광다이오드에 연결되어 일정주파수의 발진출력을 발생하는 발진기와;The present invention for achieving the above object is a tape end detection circuit having a light emitting diode for emitting light and a tape end detection sensor made of a phototransistor for receiving a light beam generated by the light emitting diode to generate a current signal, It is connected to the light emitting diode and the oscillator for generating an oscillation output of a constant frequency;
상기 포토트랜지스터의 출력전류를 전압으로 변환하는 전류/전압 변환부와; 상기의 발진부의 발진주파수를 통과대역으로 하는 대역통과필터 및; 상기 대역통과 필터의 출력전압을 입력으로 하여 기준전압과 비교하여 테이프 종단검출용 신호를 발생하는 검출부로 구성시켜서 된 것이다.A current / voltage converter converting the output current of the phototransistor into a voltage; A band pass filter having the oscillation frequency of the oscillation unit as a pass band; The output voltage of the bandpass filter is used as an input, and the detector is configured to generate a tape end detection signal compared with the reference voltage.
이하, 본 발명을 첨부된 도면에 의거하여 상세히 설명하면 다음과 같다.Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
제2도는 본 고안에 따른 테이프 종단검출 회로도인바, 테이프종단을 검출하는 센서(10)의 발광다이오드(10A)에는 일정주파수로 발광다이오드(10A)를 온/오프시키기 위한 발진기(11)가 연결되는데, 발진기(11)의 출력(A)은 제3도(A)와 같다.Figure 2 is a tape end detection circuit diagram according to the present invention, the light emitting diode (10A) of the sensor 10 for detecting the end of the tape is connected to the oscillator (11) for turning on / off the light emitting diode (10A) at a constant frequency. , The output A of the oscillator 11 is the same as FIG.
제3도(B)파형중 (가)부분은 정상적인 테이프 종단부분에서의 투과에 의한 포토트랜지스터(10B)의 출력이 아니고, 외부광원등의 노이즈에 의한 출력이다.The part (a) of the waveform in FIG. 3B is not an output of the phototransistor 10B by transmission at a normal tape end portion, but an output of noise such as an external light source.
그리고, 제3도(B)파형중(나)부분은 실제 발광다이오드(10A)에 의해서 발생된 광선이 테이프종단의 투명부분을 투과하여 수공부로 입사된 파형이다.Part (B) of FIG. 3B is a waveform in which light rays generated by the light emitting diode 10A actually pass through the transparent portion of the tape end and enter the hand part.
이렇게 포토트랜지스터(10B)에서 출력된 전류 신호는 저항(12)과 연산증폭기(13)로된 전류-전압변환기에 입력되어 전압신호로 변환된다.The current signal output from the phototransistor 10B is input to a current-voltage converter including the resistor 12 and the operational amplifier 13 and converted into a voltage signal.
전압변환된 신호는 발진기(11)의 발진주파수를 중심주파수로 하는 대역통과 필터(14)에 인가되는바, 제3도(B)파형이 각각 대역통과 필터(14)를 통과하게 되면, (가)부분의 신호는 대역통과필터(14)의 중심주파수가 아니므로 차단되고, (나)부분의 신호는 통과하게되어 제3도(C)와 같은 파형을 얻게된다.The voltage-converted signal is applied to the bandpass filter 14 having the oscillation frequency of the oscillator 11 as the center frequency. When the waveform of FIG. 3B passes through the bandpass filter 14, The signal of part) is cut off because it is not the center frequency of the band pass filter 14, and the signal of part (b) passes to obtain a waveform as shown in FIG.
대역통과필터(14)의 출력(제3도(C))은 다이오드(15), 저항(16), 콘센서(17)로된 적분회로와, 기준전압 설정용저항(18, 19) 및 비교기(20)로된 검출부에 인가된다.The output of the bandpass filter 14 (FIG. 3C) includes an integrated circuit composed of a diode 15, a resistor 16, a cone sensor 17, a reference voltage setting resistors 18, 19 and a comparator. It is applied to the detection part of (20).
이때 비교기(20)는 그의 비반전입력단자에 인가되는 입력전압레벨이 그의 반전입력단자에 설정된 기준전압레벨 보다 클 경우에는 하이상태의 신호를 출력하여 마이컴(도시하지 않았음)에 현재 테이프 종단이 검출되었음을 알려주게 된다.At this time, the comparator 20 outputs a high signal when the input voltage level applied to its non-inverting input terminal is higher than the reference voltage level set at its inverting input terminal. It will tell you that it was detected.
여기에서 대역통과필터(14)와 검출부의 출력이 동일한 것처럼 보이나, 실제 대역통과필터의 출력 진폭은 대역필터의 입력진폭에 비례하여 그레벨은 사용하는 센서의 등급(광량출력 또는 수광감도등에 의한 센서의 등급)이나, 테이프종단부의 투과도의 차이에 따라 레벨이 달라지므로 이를 바로 디지틀신호로 사용하기 곤란하여 별도의 검출부를 사용하였다.Here, the output of the bandpass filter 14 and the detector appear to be the same, but the actual amplitude of the output of the bandpass filter is proportional to the input amplitude of the bandpass filter, and the level of the bandpass filter 14 is determined by the class of the sensor used (light output or light sensitivity). Grade), or because the level varies depending on the transmittance of the end of the tape, it is difficult to use it as a digital signal.
이와같이 동작되는 본 고안은 테이프종단 검출센서의 발광부에 발진기를 부착하고, 발진수파수를 대역통과시켜 디지틀신호로 변환시킴으로써 외부광원의 반사등에 의한 테이프종단의 오검출을 방지하는 효과를 지닌 것이다.The present invention operated as described above has an effect of preventing the detection of the end of the tape by the reflection of the external light source by attaching the oscillator to the light emitting part of the tape end detection sensor, converting the oscillation wave band into a digital signal.
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR2019910017305U KR970000926Y1 (en) | 1991-10-17 | 1991-10-17 | Tape terminal detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR2019910017305U KR970000926Y1 (en) | 1991-10-17 | 1991-10-17 | Tape terminal detection circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR930009517U KR930009517U (en) | 1993-05-26 |
| KR970000926Y1 true KR970000926Y1 (en) | 1997-02-13 |
Family
ID=19320700
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR2019910017305U KR970000926Y1 (en) | 1991-10-17 | 1991-10-17 | Tape terminal detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR970000926Y1 (en) |
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1991
- 1991-10-17 KR KR2019910017305U patent/KR970000926Y1/en not_active IP Right Cessation
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| Publication number | Publication date |
|---|---|
| KR930009517U (en) | 1993-05-26 |
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