JPH05342700A - Reproducing device and detection method for presence of cassette - Google Patents

Abstract

PURPOSE:To quickly execute detection of the presence of a cassette by detecting a light output from a light emitting means with both light receiving means positioned on both sides of a tape-shaped recording medium and detecting the absence of the cassette based on the detected result. CONSTITUTION:An information as to whether the light output L from a light emitting element 21 is detected or not by a light receiving element 22T is usually the information as to whether it is the top of a tape or not. That is, after that an output corresponding to the quantity of light receiving by the element 22T is converted to digital level data by an A/D converter part 37 and a level calculation part 38, whether it is the top of the tape or nor, is detected by a controller part 31 based on the output of a comparator 40. At this time, in the case of detecting the top of the tape or in the case of detecting the end of the tape is in the case that the light L is detected by the light receiving elements 22S and 22T. Therefore, the processing for case where not cassette in loaded, is executed if it is judged that no cassette exists.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus capable of performing a reproducing operation or a recording and reproducing operation with respect to a loaded cassette tape, and more particularly to a method of detecting whether or not a cassette tape is loaded.

[0002]

2. Description of the Related Art A reproducing apparatus (digital audio tape (DAT) recording / reproducing apparatus) for converting an analog signal such as an acoustic signal into a digital signal and recording and reproducing it on a magnetic tape has been put into practical use, and a high density of the acoustic signal is obtained. Recording and high-quality recording are realized.

The recording medium DAT has a magnetic tape wound around a pair of reels, that is, an S reel (supply side reel) and a T reel (winding side reel) arranged in a cassette housing, and a reproducing device. When loaded into the cassette housing, the lid provided on the front surface side of the cassette housing is opened and the magnetic tape is pulled out (tape loading) and wound around the rotary head drum. Then, the magnetic tape is run from the S reel side to the T reel side with the rotating operation of the rotary head drum, so that the recording / reproducing of the helical scan system is performed.

In such a reproducing apparatus, it is necessary to detect whether or not the tape cassette is actually loaded when the user operates the tape, that is, executes the operation involving the rotation of the reel. This is because when the tape cassette is not loaded, it is possible to prevent the user from accepting user's operation and performing unnecessary operations such as reel rotation, and performing operations such as displaying a warning that the cassette is not loaded to the user. This is because it is preferable.

Various methods for detecting the presence / absence of a cassette have been conventionally proposed. As a typical example, as shown in FIG. 6, the cassette loading section 2 of the reproducing apparatus 1 is provided with a cassette detection switch 5 together with the erroneous erasure prevention hole detection switch 3 and the recognition hole detection switch 4, and the cassette detection switch 5 is the cassette 10 There is a method of judging the presence / absence of a cassette depending on whether or not it is pressed by the loading of the cassette.

[0006]

Considering the demands for downsizing, cost reduction, and realization of a portable device for a reproducing device, unnecessary mechanisms are reduced to reduce the number of parts and the system is simplified. In addition, it is required to reduce power consumption and extend battery life.

In response to this request, it is preferable to omit the cassette detection switch as described above, and as an alternative cassette detection method, a method of detecting the reel base FG to judge the presence / absence of a cassette has been proposed. .. In other words, when one reel is started, it is detected whether or not the other reel is pulled and rotated by the tape running by the presence or absence of the output from the FG (Frequency Generator) mounted on the reel stand, and by this, the cassette The presence or absence of wearing is determined.

However, in the case of this system, of course, FG
Depending on the number of teeth of the robot and the detection routine in the microcomputer, it takes some time after starting the activation of one reel when the cassette is not loaded and before detecting the rotation of the other reel. There is a problem that In addition, it takes a long time to detect that no cassette is loaded, that is, the idle rotation time of the reel becomes long, which is contrary to the demand for power saving.

[0009] Further, there is also proposed a reproducing apparatus which realizes the reel servo by another method by omitting the reel base FG used for the reel servo in order to further reduce the size and cost.
In this case, naturally, the reel stand FG cannot be used for detecting the presence or absence of the cassette.

[0010]

In view of the above problems, the present invention proposes a novel cassette presence / absence detecting method, which is provided in a reproducing apparatus. That is, 1
The cassette housing is provided with one light emitting means, a pair of light receiving means capable of receiving and detecting the light output from the light emitting means, and control means for controlling the light emission drive of the light emitting means and the light receiving detection operation of each light receiving means. When a tape cassette, in which a tape-shaped recording medium is wound around a pair of reels and accommodated, is loaded and the tape is in a traveling state, in the optical path from the light emitting means to the one light receiving means, in the vicinity of one reel There is a traveling path for the tape-shaped recording medium, and the traveling path for the tape-shaped recording medium in the vicinity of the other reel exists in the optical path from the light emitting means to the other light receiving means. Place means. Then, the control means is configured to determine that the tape cassette is not loaded when the light output is detected by both light receiving means when the light output is executed from the light emitting means.

[0011]

For example, as a means for detecting the tape end which is the tape end or the tape top when the tape is running on the DAT cassette by operations such as reproduction, fast forward and rewinding, Arranged light emitting means and a pair of light receiving means may be provided. In such a reproducing apparatus, the light emitting section is driven and controlled, and the presence or absence of light detection by each light receiving section is detected to detect the tape end and the tape top in the loaded tape cassette.

Here, when the cassette is not loaded, there is no obstacle (that is, tape-shaped recording medium) that blocks the light output on the light path from the light emitting means to each light receiving means. Therefore, if light reception is detected by both light receiving means, it can be determined that no cassette is loaded.

[0013]

Embodiments of the present invention will be described below with reference to FIGS. First, a method of detecting the tape end (tape end and tape top) in the loaded tape cassette will be described with reference to FIGS. 4 and 5, and thereafter, the structure of the reproducing apparatus configured to detect the cassette by utilizing this. The detection processing method will be described.

For example, when the DAT cassette 1 is loaded in the reproducing apparatus as schematically shown in FIG. 4, the front side and the lower front side of the cassette housing are opened by the mechanism on the reproducing apparatus side, and S
The magnetic tape 10 extending from the reel 2 to the T reel 3 is exposed. The exposed magnetic tape 10 is pulled out from the cassette housing by the tape loading mechanism 11 of the reproducing apparatus and is wound around the rotary head drum 12 by a predetermined angle as shown in the drawing. By rotating the rotary head drum 12 and running the tape in this state, the data recorded on the magnetic tape 10 is reproduced or the data is recorded on the magnetic tape 10.

Further, the reproducing apparatus is provided with a light emitting element 21 such as a light emitting diode, and a pair of left and right light receiving elements 22S and 22T such as phototransistors. The arrangement of these elements is tape-loaded as shown in the drawing. In this state, the light emitting element 21 to the light receiving element 22S
To the light receiving element 22T from the light emitting element 21 to the light receiving element 22T. The light path from the light emitting element 21 to the light receiving element 22T is crossed by the tape running path near the T reel 3.

In this case, the detection of the tape end or the tape top can be executed by using one of the light receiving elements 22T or 22S. For example, when playing or fast-forwarding, S
When the magnetic tape 10 is fed from the reel 2 side to the T reel 3 side, the tape end detection is performed by the detection operation of only the light receiving element 22S.

The magnetic surface of the magnetic tape 10 does not transmit the light L from the light emitting element 21, but the tape top of the magnetic tape 10 is a transparent leader tape 10a, and the light L is transmitted. Therefore, at the time of normal reproduction or fast-forwarding, the light L output from the light emitting element 22S does not reach the light receiving element 22S because the magnetic tape 10 exists on the path, but it reaches the tape end of the magnetic tape 10 on the T reel 3 side. When the leader tape 10a is positioned on the path of the light L as shown in FIG.
Is received by the light receiving element 22S. By this received light detection,
It can be detected that the tape running reaches the tape end.

On the other hand, when the magnetic tape 10 is being sent from the T reel 3 side to the S reel 2 side as in the case of rewinding, tape top detection is necessary. In this case, the light receiving element 22 is used.
Only T is used. During the rewinding, the light L output from the light emitting element 21 does not reach the light receiving element 22T because the magnetic tape 10 exists on the path, but the magnetic tape 10
When the tape top is also wound up on the S reel 5 side, the light L is received by the light receiving element 22T because the leader tape 10a is located on the path of the light L as shown in FIG. 7B. It By detecting the received light, it can be detected that the tape running in the rewind direction has reached the tape top.

In this embodiment, the tape end detecting mechanism is used to detect the tape end and the tape top, and also to detect the presence / absence of a cassette, and the construction of the main part is shown in FIG. Reference numeral 30 denotes a system controller configured by a microcomputer. This system controller 30 is a mechanism (not shown) in the playback device.
In addition to performing the operation control of the circuit section, the drive control of the light emitting element 21 and the processing of the detection signal by the light receiving elements 22S and 22T are performed so that the tape end detection, the tape top detection, and the cassette presence / absence detection can be performed. Has been done.

Reference numeral 31 is a control unit (CPU), which performs arithmetic processing based on various input signals such as an operation program held in the memory unit 31M or various detection signals and user operation signals from an operation unit (not shown). Outputs various control signals. Reference numeral 32 is a pulse generator that outputs a pulse as a switching control signal to the switching element (FET) 33 based on a command from the controller 31.

The FET 33 is connected to the light emitting element 21 via the resistor R ₁ from the microcomputer port 34. When the FET 33 is turned on by the pulse output from the pulse generator 32, a current from a power supply voltage (not shown) emits light. Element 21
And the light L is output.

The output from the light receiving element 22T, that is, the current value based on the received light level is converted into a voltage value by the resistor R ₂ and supplied from the microcomputer port 35 to the A / D conversion section 37 to be a digital value. .. Similarly, the output current value from the light receiving element 22S is converted into a voltage value by the resistor R ₃ , and is supplied from the microcomputer port 36 to the A / D converter 37 to be a digital value.

Reference numeral 38 is a level calculation unit for calculating the received light detection value input via the A / D conversion unit 37. As described above, when the tape end is detected by the light emitting element 21 and the light receiving elements 22S and 22T, the driving of the light emitting element 21 is turned on / off at a certain high frequency cycle. That is, when the light emitting element 21 is driven to emit light, the pulse generator 32 outputs F
A high-frequency pulse is applied to the ET33 to bring it into a high-speed blinking state.

Therefore, also in the value detected by the light receiving element 22S or 22T and digitized by the A / D converter 37, the high level value and the low level value appear corresponding to the pulse period. The level calculation unit 38 includes the pulse generation unit 32.
Receives the timing signal S _TM corresponding to the pulse output to the FET 33, and based on this, determines the timing when the detection value becomes the high level and the timing when the detection value becomes the low level, and calculates the high level value-the low level value. The detection level is calculated by performing.

By calculating the detection level in this way, for example, leaked light from the outside is detected by the light receiving elements 22S and 22T.
Even in the case where the light is received by, it is possible to accurately obtain the actual level of the detected light component.

The detection level obtained by the level calculation unit 38 is set to the reference voltage level value V _th e via the switch 39.
Is supplied to the comparator 40 for comparison, and the comparison result is supplied to the control unit 31. The switching control of the switch 39 is performed by a signal from the control unit 31.

The operation of detecting the tape top, the tape end, and the presence / absence of a cassette, which is executed by the control unit 31 in such a configuration, will be described with reference to the flowchart of FIG. When the user performs an operation (reel start command) that involves reel rotation, such as playback, recording, fast-forwarding, and rewinding (F
101), the control unit 31 performs reel start control and turns on the light emitting element 21 (F102). That is, the pulse generator 32 outputs a drive pulse to the FET 33 to execute the optical output (high-frequency blinking output) from the light emitting element 21.

Then, it is discriminated whether the reel rotation such as reproduction, recording, or fast-forward is the forward operation or the reel rotation such as rewinding is the reverse operation (F103).
If it is the forward direction, the tape end detection (tape end detection) on the S reel side is first executed (F104). That is, the switch 39 is connected to the E contact so that the detection information of the light receiving element 22S is supplied to the comparator 40.

Here, normally, the light output L of the light emitting element 21 is shielded by the magnetic tape 10 or passes through the leader tape 10a and reaches the light receiving element 22S. The output according to the amount of light received by the light receiving element 22S is the A / D conversion unit 3
7. After being converted to digital level data by the level calculation unit 42, it is supplied to the comparator 40 via the switch 39 and compared with the threshold level V _th e, so the output of the comparator 45 is in the tape end state. This information becomes whether or not it is returned to the control unit 31.

When the tape end is detected (F105),
Since it is not possible to run the reels for reproduction, fast-forwarding, recording, etc., running stop control is executed for a reel drive mechanism unit (not shown) (F106). If it is not the tape end, the process returns to step F103 to continue the tape end detection operation.

By the way, the case where the tape end is detected in step F105 may be the case where the cassette is not loaded in the first place in addition to the case where the tape end is actually reached. Therefore, it must be distinguished. ..
In the case of the tape end shown in FIG. 5A, the light L from the light emitting element 21 may be changed depending on the light receiving element 22T.
Should not be detected because it is blocked by the magnetic tape 10. Therefore, next, tape end detection (tape top detection) on the T reel side is executed (F107). That is, the switch 39 is connected to the T contact so that the detection information of the light receiving element 22T is supplied to the comparator 40.

When a cassette tape is loaded here, the tape top state cannot occur, so the light output L of the light emitting element 21 is shielded by the magnetic tape 10 and is not detected by the light receiving element 22T. That is, the tape top detection information is not supplied to the control unit 31. Therefore, in this case, the tape end may be determined (F108), and then the tape end detection processing is executed (F109). For example, "T
"APE END" is displayed or an automatic rewinding operation is performed.

If it is determined in step F103 that the reel rotation is in the reverse direction, tape end detection (tape top detection) on the T reel side is executed (F11).
0). That is, the switch 39 is connected to the T contact so that the detection information of the light receiving element 22T is supplied to the comparator 40.

In this case, normally, the information as to whether or not the light output L of the light emitting element 21 is detected by the light receiving element 22T is the information as to whether or not the tape top is in the state. That is, the output depending on the amount of light received by the light receiving element 22T
7. After being converted into digital level data by the level calculation unit 38, it is supplied to the comparator 40 via the switch 39, compared with the threshold level V _th e, and the output of the comparator 40 determines whether or not the tape top state is established. The control unit 31 detects it.

When the tape top is detected (F111),
Since reel traveling for rewinding or the like cannot be performed, traveling stop control is executed for a reel drive mechanism (not shown) (F11
2). If it is not the tape top, the process returns to step F103 to continue the tape top detection operation.

Here, also in the case where the tape top is detected in step F111, in addition to the state where the tape top is actually formed as shown in FIG. 5B, the case where the cassette is not loaded in the first place is also considered. Therefore, the tape end detection on the S reel side (tape end detection) is subsequently executed (F113). That is, the switch 39 is connected to the E contact so that the detection information of the light receiving element 22S is supplied to the comparator 40.

When the tape cassette is loaded here, the tape end state is not detected, so in this case it may be judged that the tape top (F114), and then the tape top detection processing is executed (F115). For example, it causes the display section to display "TAPE TOP".

When the tape top is detected in step F108 or the tape end is detected in step F114, the light L is detected by both the light receiving elements 22S and 22T as schematically shown in FIG. This is the case when the cassette is not loaded. Therefore, it is determined that there is no cassette, and the process proceeds to step F116, and the process corresponding to the unloaded cassette, for example, "NO TAP"
Display control of "E" is executed.

According to this embodiment for performing such cassette presence / absence detection operation, for example, when a reproduction operation is mistakenly performed, it is possible to realize from the start of the reel to the detection of the absence of the cassette in a considerably short time, which is wasteful. Power consumption can be eliminated. In addition, since a dedicated switch mechanism for detecting the cassette is not required, it is possible to meet the demand for downsizing of the device and cost reduction by reducing the number of parts.

In the processing of FIG. 2 in this embodiment, the presence / absence of the cassette is detected after the reel is activated. However, for example, when a reel activation command is issued, the presence / absence of the cassette is detected before the reel is activated. By assembling, it is even more effective in reducing unnecessary power consumption.

By the way, by using the tape end detecting mechanism as the cassette presence / absence detecting mechanism as in the embodiment,
As described above, it is suitable for downsizing and cost reduction of equipment, but when it is only intended to quickly detect the presence / absence of a cassette, the cassette presence / absence detection mechanism as described above is independent of the tape end detection mechanism. May be provided. Further, in the embodiment, the reproducing apparatus using the cassette tape as the recording medium has been described, but it can be applied as a tape presence / absence detecting means in the reproducing apparatus corresponding to the so-called open reel tape.

[0042]

As described above, according to the present invention, the absence of a cassette is detected by detecting the light output from the light emitting means through the tape-shaped recording medium by both the light receiving means located on both sides. The cassette presence / absence detection operation can be performed quickly. In addition, for the device provided with the light emitting means and the light receiving means as the tape end detecting means, since it is configured to detect the presence or absence of the cassette by using this, a dedicated mechanism and parts for detecting the presence or absence of the cassette are unnecessary. As a result, the number of parts can be reduced, and since the cassette detection operation can be completed quickly, there is an effect that wasteful power consumption due to so-called idle rotation does not increase, which is especially useful as a small portable playback device. Suitable for

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of a reproducing device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a cassette presence / absence detection method in the embodiment.

FIG. 3 is an explanatory diagram of a cassette presence / absence detection operation in the embodiment.

FIG. 4 is an explanatory diagram of a tape end detecting operation in the reproducing apparatus of the embodiment.

FIG. 5 is an explanatory diagram of a tape end detection state in the reproducing apparatus of the embodiment.

FIG. 6 is an explanatory diagram of a conventional cassette presence / absence detection mechanism.

[Explanation of symbols]

 1 Tape Cassette 21 Light-Emitting Element 22S, 22T Light-Receiving Element 31 Control Section 32 Pulse Generation Section 33 FET 37 A / D Conversion Section 38 Level Calculation Section 39 Switch 40 Comparator

Claims (3)

[Claims] 1. A light emitting means and a pair of light receiving means capable of receiving and detecting an optical output from the light emitting means.
A light emitting drive control of the light emitting means and a control means for detecting the light receiving detection operation of each of the light receiving means are provided, and the one light receiving means winds and stores a tape-shaped recording medium around a pair of reels in a cassette housing. When the tape cassette is loaded and the tape is in a traveling state, the traveling path of the tape-shaped recording medium near the one reel is present in the optical path from the light emitting means to the one light receiving means. The other light receiving means is arranged in the vicinity of the other reel in the optical path from the light emitting means to the other light receiving means when the tape cassette is loaded and the tape is in a traveling state. The recording medium is arranged so that a traveling path exists, and the control unit controls the light output when the light output is performed from the light emitting unit. Reproducing apparatus when it is received and detected by both light receiving means, characterized in that it is configured to determine the tape cassette is not loaded. 2. A light path from a light emitting means to one light receiving means when a tape cassette in which a tape-shaped recording medium is wound and housed in a pair of reels is loaded in a cassette housing and the tape is in a traveling state. In the optical path from the light emitting means to the other light receiving means, there is a traveling path of the tape-shaped recording medium near the one reel.
The light emitting means and the one and the other light receiving means are arranged so that the traveling path of the tape-shaped recording medium near the other reel exists, and when the light output is executed from the light emitting means, the light is emitted. A method for detecting the presence / absence of a cassette, wherein when the output is detected by both of the light receiving means, it is determined that a tape cassette is not loaded. 3. One light emitting means, and a pair of light receiving means capable of receiving and detecting the light output from the light emitting means,
A light emitting drive control of the light emitting means and a control means for detecting the light receiving detection operation of each of the light receiving means are provided, and the one light receiving means winds and stores a tape-shaped recording medium around a pair of reels in a cassette housing. When the tape cassette is loaded and the tape is in a traveling state, the traveling path of the tape-shaped recording medium near the one reel is present in the optical path from the light emitting means to the one light receiving means. The other light receiving means is arranged in the optical path from the light emitting means to the other light receiving means in the vicinity of the other reel when the tape cassette is loaded and the tape is in a traveling state. The recording medium is arranged such that a traveling path exists, and the control unit controls the light output when the light output is performed from the light emitting unit. When the light reception is detected by only one of the one or the other light receiving means, it is determined that the tape-shaped recording medium in the loaded tape cassette reaches the tape end or the tape top, and the light output from the light emitting means is executed. When the optical output is detected by both of the light receiving means, the reproducing apparatus is configured to determine that the tape cassette is not loaded.