JPH0433563Y2 - - Google Patents
Info
- Publication number
- JPH0433563Y2 JPH0433563Y2 JP18812486U JP18812486U JPH0433563Y2 JP H0433563 Y2 JPH0433563 Y2 JP H0433563Y2 JP 18812486 U JP18812486 U JP 18812486U JP 18812486 U JP18812486 U JP 18812486U JP H0433563 Y2 JPH0433563 Y2 JP H0433563Y2
- Authority
- JP
- Japan
- Prior art keywords
- tape
- light
- receiving element
- light receiving
- output
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000001514 detection method Methods 0.000 claims description 22
- 238000000605 extraction Methods 0.000 claims description 4
- 238000010586 diagram Methods 0.000 description 12
- 230000003321 amplification Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
Description
【考案の詳細な説明】
（産業上の利用分野）
本考案は、テープ状記録媒体を用いて情報の記
録、再生等を行う磁気記録再生装置のテープ端検
出回路に関し、例えばビデオテープレコーダやオ
ーデイオテープレコーダ等に利用される。[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a tape end detection circuit for a magnetic recording and reproducing device that records and reproduces information using a tape-shaped recording medium, Used in tape recorders, etc.
（従来の技術）
テープ端検出回路を備えた磁気記録再生装置の
構造の一例を第３図に示す。(Prior Art) FIG. 3 shows an example of the structure of a magnetic recording/reproducing apparatus equipped with a tape end detection circuit.
同図において、１１は装置本体、１２は装置本
体１１に装填されたテープカセツト、１３は記録
テープ、１４は装填状態のテープカセツト１２の
略中央位置に配置された発光素子２３（第４図参
照）を有する発光部、１５，１６はテープカセツ
ト１２の両端にそれぞれ配置された受光素子２４
（第４図参照）を有する受光部である。 In the figure, 11 is the main body of the apparatus, 12 is a tape cassette loaded in the main body 11 of the apparatus, 13 is a recording tape, and 14 is a light emitting element 23 disposed approximately in the center of the loaded tape cassette 12 (see FIG. 4). ), and 15 and 16 are light receiving elements 24 arranged at both ends of the tape cassette 12, respectively.
(See FIG. 4).
上記構成において、記録テープ１３の始端及び
終端を検出する必要があるときは発光部１４を常
時発光させておく。記録テープ１３の始端及び終
端には透明又は乳白色のリーダテープ部が設けら
れており、例えば発光部１４からの光をリーダテ
ープ部を通して一方の受光部１５で検出した場合
は記録テープ１３の始端を、又他方の受光部１６
で検出した場合は終端をそれぞれ検出したことに
なる。この後、装置本体１１の動作を停止モード
にしたり、あるいは記録テープ１３を巻き戻した
後停止モードにしたりする。 In the above configuration, when it is necessary to detect the start and end ends of the recording tape 13, the light emitting section 14 is kept emitting light at all times. A transparent or milky white leader tape section is provided at the beginning and end of the recording tape 13. For example, when light from the light emitting section 14 is detected by one of the light receiving sections 15 through the leader tape section, the starting end of the recording tape 13 is detected. , and the other light receiving section 16
If it is detected, it means that each end has been detected. Thereafter, the operation of the main body 11 of the apparatus is set to a stop mode, or the recording tape 13 is rewound and then set to a stop mode.
第４図に従来のテープ端検出回路の一例を示
す。 FIG. 4 shows an example of a conventional tape end detection circuit.
同図において、発光部１４は、パルス発生器２
１、トランジスタ２２、LED等の発光端子２３、
抵抗R1，R2等で構成され、受光部１５（又は１
６）は、ホトトランジスタ等の受光素子２４、抵
抗R3，R4等で構成されている。 In the figure, the light emitting section 14 is connected to the pulse generator 2.
1, transistor 22, light emitting terminal 23 such as LED,
It is composed of resistors R 1 , R 2 , etc., and is connected to the light receiving section 15 (or 1
6) is composed of a light receiving element 24 such as a phototransistor, resistors R 3 and R 4 , and the like.
このテープ端検出回路の動作を第５図の波形図
を参照して説明する。第５図ａは第４図の回路部
における点の波形、同図ｂは点の波形、同図
ｃは点の波形をそれぞれ示している。 The operation of this tape end detection circuit will be explained with reference to the waveform diagram of FIG. 5A shows a waveform at a point in the circuit section of FIG. 4, b shows a waveform at a point, and c shows a waveform at a point in the same figure.
パルス発生器２１により一定周期のパルスを発
生し、次段のトランジスタ２２でパルス駆動によ
る電流増幅を行い、発光素子２３を発光させてお
く。 A pulse generator 21 generates a pulse with a constant period, and a transistor 22 in the next stage performs current amplification by pulse driving to cause the light emitting element 23 to emit light.
ここで、発光素子２３からの光は、例えば記録
テープ１３が始端もしくは終端でないときは記録
テープ１３を透過しないため、受光部１５（又は
１６）の受光素子２４はOFFとなり、検出信号
として例えば5Vが次段のマイクロコンピユータ
（図示省略）に入力される。この場合、装置の動
作は現在モードを保持する。 Here, since the light from the light emitting element 23 does not pass through the recording tape 13, for example, when the recording tape 13 is not at the beginning or end, the light receiving element 24 of the light receiving section 15 (or 16) is turned OFF, and the detection signal is, for example, 5V. is input to the next stage microcomputer (not shown). In this case, the operation of the device remains in the current mode.
次に、記録テープ１３が走行しテープの始端あ
るいは終端付近までくると、透明又は乳白色のリ
ーダテープ部となるため、発光素子２３からの発
光パルスは該リーダテープ部を透過して受光素子
２４に到達する。したがつて、受光素子（ホトト
ランジスタ）２４のコレクタ出力には第５図ｃに
示す波形のパルスが検出パルスとして出力する。
そして、この検出パルスの例えば3Vのスレツシ
ユレベルを判別レベルとし、例えば、マイクロコ
ンピユータ判別条件として3Vの検出ポイントを
３パルス分カウントしたときを検出信号とし、記
録テープ１３の停止もしくは巻き戻し等の動作を
行う。 Next, when the recording tape 13 runs and reaches near the beginning or end of the tape, it becomes a transparent or milky white leader tape section, so the light emitting pulse from the light emitting element 23 passes through the leader tape section and reaches the light receiving element 24. reach. Therefore, a pulse having a waveform shown in FIG. 5c is output as a detection pulse to the collector output of the light receiving element (phototransistor) 24.
Then, the threshold level of this detection pulse, for example 3V, is set as a discrimination level, and the time when the 3V detection point is counted for 3 pulses is set as a detection signal, for example, as a microcomputer discrimination condition, to stop or rewind the recording tape 13, etc. perform an action.
（考案が解決しようとする問題点）
しかしながら、上記したような従来回路の場
合、受光素子２４には発光素子２３からの光以外
に太陽光等の外来光も入射し易く、これらの外来
光は直流成分であるために、受光素子２４のコレ
クタ出力は発光素子２３からのパルス（交流）成
分と外来光の直流成分とが加わり、この結果、ス
レツシユレベルが変動したり〔第５図ｃ参照〕、
パルスの周期が一定でなくなつたりする。このた
め、この出力パルスを用いて判別動作を行うマイ
クロコンピユータの判別誤動作を生じるといつた
問題があつた。(Problems to be solved by the invention) However, in the case of the conventional circuit as described above, in addition to the light from the light emitting element 23, external light such as sunlight is likely to enter the light receiving element 24, and these external lights are Since it is a DC component, the collector output of the light-receiving element 24 includes a pulse (AC) component from the light-emitting element 23 and a DC component of the external light, and as a result, the threshold level fluctuates [see Figure 5c]. ],
The pulse period may become irregular. For this reason, there has been a problem in that the microcomputer that performs the discrimination operation using this output pulse may malfunction in the discrimination operation.
（問題点を解決するための手段）
本考案に係る磁気記録再生装置のテープ端検出
回路は、テープ状記録媒体を用いて情報の記録、
再生等を行う磁気記録再生装置であつて、前記テ
ープ状記録媒体を介して発光素子を有する発光部
と受光素子を有する受光部とが配置され、前記発
光素子から発せられた光を前記テープ状記録媒体
を通して前記受光素子で受光することにより前記
テープ状記録媒体の始端もしくは終端を検出する
ように構成されたテープ端検出回路において、前
記受光素子の出力側に比較器と直流成分だけを抽
出する抽出手段とが接続され、該比較器の２つの
入力端子のうち一方の入力端子には前記受光素子
の出力を直接入力し、他方の入力端子には前記受
光素子の出力を前記抽出手段を通して入力し、こ
の比較器の出力信号をテープ端検出信号として用
いるものである。 (Means for Solving the Problems) A tape end detection circuit of a magnetic recording/reproducing device according to the present invention records information using a tape-shaped recording medium.
A magnetic recording and reproducing device that performs reproduction, etc., in which a light emitting section having a light emitting element and a light receiving section having a light receiving element are disposed through the tape-shaped recording medium, and the light emitted from the light emitting element is transferred to the tape-shaped recording medium. In a tape end detection circuit configured to detect the start or end of the tape-shaped recording medium by receiving light through the recording medium and by the light receiving element, a comparator and only a DC component are extracted on the output side of the light receiving element. The output of the light receiving element is directly input to one of the two input terminals of the comparator, and the output of the light receiving element is input through the extracting means to the other input terminal. The output signal of this comparator is used as a tape end detection signal.
（作用）
受光素子の出力側に比較器と直流成分だけを抽
出する抽出手段とを接続し、比較器の２つの入力
端子のうち反転入力端子には受光素子の出力を直
接入力し、非反転入力端子には前記受光素子の出
力を前記抽出手段を通して入力する。これによ
り、例えば太陽光等の直流成分の外来光が受光素
子に加わつて該受光素子の出力パルスの直流レベ
ルが変化しても、比較器の両入力の直流レベルも
これに応じて変化する。(Function) A comparator and extraction means for extracting only the DC component are connected to the output side of the light receiving element, and the output of the light receiving element is directly input to the inverting input terminal of the two input terminals of the comparator. The output of the light receiving element is inputted to the input terminal through the extraction means. Thereby, even if the DC level of the output pulse of the light receiving element changes due to external light having a DC component such as sunlight being applied to the light receiving element, the DC levels of both inputs of the comparator will change accordingly.
（実施例）
以下、本考案の一実施例を図面を参照して説明
する。(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.
第１図に本考案のテープ端検出回路を示す。 FIG. 1 shows the tape end detection circuit of the present invention.
同図において、１はパルス発生器、２はトラン
ジスタ、３はLED等の発光素子、４はホトトラ
ンジスタ等の受光素子であり、これらの回路部品
は前記した従来例のものと同様である。本考案で
は、この受光素子４のコレクタ出力に比較器５及
び直流成分だけを抽出するローパスフイルタ
（LPF）６を接続したものである。 In the figure, 1 is a pulse generator, 2 is a transistor, 3 is a light emitting element such as an LED, and 4 is a light receiving element such as a phototransistor. These circuit components are the same as those in the conventional example described above. In the present invention, a comparator 5 and a low pass filter (LPF) 6 for extracting only the DC component are connected to the collector output of the light receiving element 4.
すなわち、比較器５の２つの入力端子のうち反
転入力端子（−）に受光素子４のコレクタ出力端
子を直接接続し、出力成分である交流成分と直流
成分のミツクス信号を入力する。また、比較器５
の非反転入力端子（＋）には、受光素子４のコレ
クタ出力端子をLPF６を介して接続し、この
LPF６で出力成分のうち直流成分だけを取り出
して比較器５の基準電圧とするものである。 That is, the collector output terminal of the light-receiving element 4 is directly connected to the inverting input terminal (-) of the two input terminals of the comparator 5, and a mix signal of AC and DC components as output components is input thereto. Also, comparator 5
The collector output terminal of the light receiving element 4 is connected to the non-inverting input terminal (+) of the
The LPF 6 extracts only the DC component out of the output components and uses it as a reference voltage for the comparator 5.
次に、上記構成のテープ端検出回路の動作を第
２図の波形図を参照して説明する。ただし、発光
素子３からの光を受光素子４で受けるまでの動作
は前記した従来例の場合と同様であるので、ここ
ではその説明を省略する。なお、第２図ａは第１
図の回路図における点の波形図、同図ｂは点
の波形図、同図ｃは点の波形図、同図ｄは点
の波形図、同図ｅは点の波形図をそれぞれ示し
ている。 Next, the operation of the tape end detection circuit having the above configuration will be explained with reference to the waveform diagram of FIG. However, since the operation up to the time when the light receiving element 4 receives the light from the light emitting element 3 is the same as that of the conventional example described above, the explanation thereof will be omitted here. Note that Figure 2a is the first
In the circuit diagram shown in the figure, b shows a waveform diagram of a point, c shows a waveform diagram of a point, d shows a waveform diagram of a point, and e shows a waveform diagram of a point. .
すなわち、発光素子３からの光が受光素子４に
到達した場合、比較器５の反転入力端子（−）に
は直流分3Vと受光素子４の出力パルスのAC分
〔第２図ｃ参照〕が入力され、非反転入力端子
（＋）にはLPF６によつてAC分を除去した直流
レベル3V〔第２図ｄ参照〕が比較器５の基準電圧
として入力される。この結果、比較器５の出力反
転入力端子（−）のACパルス分の平均値レベル
3Vをスレツシユホールドとした第２図(e)に示す
方形波パルスとなる。この場合、もし外来光が受
光素子４に入射して出力パルスに加わる直流レベ
ル〔第２図ｃ参照〕が変化しても、比較器５の反
転入力端子（−）及び非反転入力端子（＋）の直
流レベルもこれに応じてそれぞれ変化することに
なるので、比較器５の出力は反転入力端子（−）
のAC入力レベルの平均値レベルをスレツシユホ
ールドとする第２図ｅに示す方形波パルスとな
り、安定した出力を得ることができるものであ
る。このときの第２図ｅに示す出力パルスの検出
周期は、同図ａに示す駆動パルスの周期と略同じ
であり、外来光に影響されない極めて安定なテー
プ端検出回路とすることができる。 That is, when the light from the light emitting element 3 reaches the light receiving element 4, the inverting input terminal (-) of the comparator 5 receives a DC component of 3V and an AC component of the output pulse of the light receiving element 4 [see Figure 2 c]. A DC level of 3 V (see FIG. 2 d) from which the AC component has been removed by the LPF 6 is input to the non-inverting input terminal (+) as the reference voltage of the comparator 5. As a result, the average level of AC pulses at the output inversion input terminal (-) of comparator 5
The result is a square wave pulse as shown in Figure 2(e) with a threshold of 3V. In this case, even if the external light enters the light receiving element 4 and the DC level added to the output pulse (see Figure 2c) changes, the inverting input terminal (-) and non-inverting input terminal (+) of the comparator 5 change. ) will change accordingly, so the output of comparator 5 will be connected to the inverting input terminal (-).
The pulse is a square wave as shown in FIG. 2e, with the average level of the AC input level as the threshold, and a stable output can be obtained. At this time, the detection period of the output pulse shown in FIG. 2e is approximately the same as the period of the drive pulse shown in FIG.
（考案の効果）
以上説明したように、本考案によれば、外来光
等に影響されない極めて安定な磁気記録再生装置
のテープ端検出回路を実現することができる。(Effects of the Invention) As described above, according to the present invention, it is possible to realize an extremely stable tape end detection circuit for a magnetic recording/reproducing device that is not affected by external light or the like.
第１図は本考案のテープ端検出回路図、第２図
は第１図に示すテープ端検出回路の各部の信号波
形図、第３図はテープ端検出回路を備えた磁気記
録再生装置の概略構成図、第４図は従来のテープ
端検出回路図、第５図は第４図に示すテープ端検
出回路の各部の信号波形図である。
１……パルス発生器、２……トランジスタ、３
……発光素子、４……受光素子、５……比較器、
６……ローパスフイルタ。
Fig. 1 is a diagram of the tape end detection circuit of the present invention, Fig. 2 is a signal waveform diagram of each part of the tape end detection circuit shown in Fig. 1, and Fig. 3 is a schematic diagram of a magnetic recording/reproducing device equipped with the tape end detection circuit. FIG. 4 is a diagram of a conventional tape end detection circuit, and FIG. 5 is a signal waveform diagram of each part of the tape end detection circuit shown in FIG. 4. 1...Pulse generator, 2...Transistor, 3
... Light emitting element, 4 ... Light receiving element, 5 ... Comparator,
6...Low pass filter.
Claims (1)
を行う磁気記録再生装置であつて、前記テープ状
記録媒体を介して発光素子を有する発光部と受光
素子を有する受光部とが配置され、前記発光素子
から発せられた光を前記テープ状記録媒体を通し
て前記受光素子で受光することにより前記テープ
状記録媒体の始端もしくは終端を検出するように
構成されたテープ端検出回路において、 前記受光素子の出力側に比較器と直流成分だけ
を抽出する抽出手段とが接続され、該比較器の２
つの入力端子のうち一方の入力端子には前記受光
素子の出力を直接入力し、他方の入力端子には前
記受光素子の出力を前記抽出手段を通して入力
し、この比較器の出力信号をテープ端検出信号と
して用いることを特徴とする磁気記録再生装置の
テープ端検出回路。[Claims for Utility Model Registration] A magnetic recording and reproducing device that records and reproduces information using a tape-shaped recording medium, which includes a light-emitting section having a light-emitting element and a light-receiving element via the tape-shaped recording medium. a tape end detector configured to detect a starting end or a trailing end of the tape-shaped recording medium by receiving light emitted from the light-emitting element by the light-receiving element through the tape-shaped recording medium; In the circuit, a comparator and extraction means for extracting only the DC component are connected to the output side of the light receiving element, and two of the comparators
The output of the light receiving element is directly input to one of the two input terminals, the output of the light receiving element is input through the extraction means to the other input terminal, and the output signal of this comparator is used to detect the end of the tape. A tape end detection circuit for a magnetic recording/reproducing device characterized in that it is used as a signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18812486U JPH0433563Y2 (en) | 1986-12-05 | 1986-12-05 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18812486U JPH0433563Y2 (en) | 1986-12-05 | 1986-12-05 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6391834U JPS6391834U (en) | 1988-06-14 |
| JPH0433563Y2 true JPH0433563Y2 (en) | 1992-08-11 |
Family
ID=31139200
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18812486U Expired JPH0433563Y2 (en) | 1986-12-05 | 1986-12-05 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0433563Y2 (en) |
-
1986
- 1986-12-05 JP JP18812486U patent/JPH0433563Y2/ja not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6391834U (en) | 1988-06-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR940001751B1 (en) | Loading motor playing apparatus for vtr | |
| JPH0433563Y2 (en) | ||
| JPS60262061A (en) | Zero-point passage detection circuit for signal | |
| JPH0643861Y2 (en) | Video motor pre-coder reel motor braking device | |
| KR870003299Y1 (en) | Slow control device | |
| KR900007821Y1 (en) | Tape state sensing circuit for vcr | |
| KR920003494Y1 (en) | For audio device autostop circuit | |
| JPS5827383Y2 (en) | Tape end detection device for tape recorder | |
| JPH0138747Y2 (en) | ||
| KR910006345Y1 (en) | Automatic selecting music signal generating circuit | |
| KR930001753Y1 (en) | Viss detecting circuit | |
| JPS5842669U (en) | electronic device with a motor | |
| KR900008393Y1 (en) | Slow tracking automatic adjustment circuit in video tape recorder | |
| KR0150120B1 (en) | Recording type detecting circuit | |
| KR890000782Y1 (en) | Drop out detecting circuit of video disk player | |
| JPS62155783A (en) | Stop device for revolution of motor | |
| JPS6357861B2 (en) | ||
| KR910008171Y1 (en) | First and end checking circuit of video tape | |
| KR890000153Y1 (en) | Tape record and reproducing and detecting circuit | |
| KR890004232Y1 (en) | Automatic stopping circuit of tape recorder | |
| JPH0450569Y2 (en) | ||
| KR890001943B1 (en) | Index bust integration circuit in magnetic device | |
| JPS6220920Y2 (en) | ||
| JPS6125055Y2 (en) | ||
| JPS60118762U (en) | Motor fan rotation detector |