JPH0154762B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application) The present invention relates to an automatic fade-out device for a tape recorder that can automatically perform fade-out processing at the end of a tape recording.

(Prior Art) Conventionally, in tape recorders, when it is impossible to record until the end of the tape, for example, until the end of a song, fade-out processing has often been performed. As is well known, the method is
During recording, the end of the tape is visually detected and the recording level is gradually lowered.

However, with this conventional method, during recording,
The remaining amount of tape must be constantly monitored, and it is extremely difficult to find the fade-out start position slightly before the boundary between the recordable area near the end of the tape and the leader tape in a timely manner and apply the fade-out. There were flaws.

(Objective) An object of the present invention is to provide an automatic fade-out device for a tape recorder that eliminates the drawbacks of the prior art described above and can easily perform fade-out processing at the end of a tape recorded until the end of the tape.

(Summary) In order to achieve the above object, the present invention provides, in a recording state, (1) tape end detection means for detecting the end of the tape and outputting a tape end detection signal; (2) the tape end detection signal; means for outputting an erase stop command signal and a tape rewind search signal in response to the erase stop command signal; (3) means for stopping supply of the erase signal to the erase head based on the erase stop command signal; ) means for rewinding the tape using the rewind search signal; (5) means for detecting a recording end of the tape during rewinding and outputting a recording end detection signal; (6) an end of the tape. rewinding a predetermined length corresponding to at least the length of the leader tape from the first
(7) If the recording end detection signal is not input within the first time period, at least a rewind search stop signal is detected. If the recording end detection signal is input within the first time period, rewinding is further continued for a second time period corresponding to the scheduled length of the tape, and then a fade out enable signal and rewinding are performed. means for outputting a search stop signal and a playback start signal, respectively; (8) means for stopping rewinding of the tape in response to the rewind search stop signal and playback start signal, and bringing the tape into a playback state; (9) the above-mentioned A fade-out means for supplying an erase signal for fade-out to the erase head based on a fade-out enable signal is provided.

(Example) Hereinafter, the present invention will be explained using the drawings.

FIG. 1 is a block diagram showing an embodiment of an automatic fade-out device for a tape recorder according to the present invention.

In the figure, 1 is a tape, 2 is an erasing head,
3 is a recording/playback head, 4 is a tape drive device, 5 is a control circuit, 6 is a central control unit (CPU),
7 is a time counter, 8 is a tape end detection device,
9 is a fade out circuit, 10 is a signal detection circuit,
11 is a reproduction circuit, and 12 is a fade-out mode selection switch.

Further, FIG. 2 is a plan view showing the vicinity of the terminal end of the tape 1 for explaining the operation of FIG. 1.

Here, the operation of this embodiment will be explained.

In FIG. 1, when performing fade-out processing at the end of recording, the recording mode is selected at the start of recording, the selection switch 12 is turned on, and a fade-out selection signal is supplied to the CPU 6.

In this state, when the recording/reproducing head 3 records completely to the end D of the recordable area A on the tape 1, for example, and reaches the end E of the tape 1 via the leader tape B, the tape end detection device 8 detects the end of tape 1 using a well-known method, and sends a corresponding signal (tape end detection signal) to the CPU.
Supply to 6.

Upon receiving the tape end detection signal, the CPU 6 inverts the bias signal that had been supplied to the bias terminal b of the fade-out circuit 9 (erase stop command signal), and as will be described later, erases the erase head 2. At the same time, a rewind search signal for rewinding the tape 1 is supplied to the control circuit 5, and a clear signal is supplied to the time counter 7.

Upon receiving the rewind search signal, the control circuit 5 almost simultaneously moves the tape 1 to the end E.
The control signal for rewinding from the tape drive device 4
supply to. As a result, tape 1 is stored at counter 7.
It is rewound from the end position E while being counted by .

Next, tape 1 is rewound and the recording/playback head 3
When it reaches the end D of the recordable area A, that is, the end of recording, the recording/playback head 3 detects the playback signal and sends the signal to the playback circuit 11 and the signal detection circuit 1.
Supply to 0. As a result, the signal detection circuit 10 receives this playback signal and detects the recording end detection signal.
Supply to CPU6.

The CPU 6 compares the count value input from the time counter 7 when receiving this recording end detection signal with a first specified number set in advance by the CPU 6.

Note that the first specified number provides a standard for detecting the end D of the recordable area A on the tape 1, and theoretically, from the end E of the tape 1 to the end D of the recordable area A. This value corresponds to the count number of the counter 7 when the leader tape B of the tape 1 is rewound until the end. However, since there is some variation in the length of the leader tape B for each tape, the first specified number is at least
The value must be selected to correspond to the maximum allowable length of leader tape B.

Since the first specified number is selected as described above, the count value of the time counter 7 at the time when the recording end detection signal is obtained is equal to or less than the first specified number (count value≦first). The specified number) means that the recordable area A has been completely recorded up to the end D. At this time, since fade-out processing is necessary, the CPU 6 outputs a signal to clear the counter 7. Therefore,
The counter 7 will start counting up again.

On the other hand, if the count value of the time counter 7 at the time when the recording end detection signal is obtained is larger than the first specified number, it means that the recording has ended before reaching the termination point D. Therefore, fade-out processing is not necessary. In this case, the CPU 6 does not output a clear signal to the counter 7 but outputs a rewind search stop signal to the control circuit 5. As a result, the tape 1 is stopped from rewinding due to the operation of the tape drive device 4.

In this case, if the CPU 6 supplies a fast forward command signal to the control circuit 5 along with the rewind search stop signal, the tape 1
can be completely wound up again.

Next, when the clear signal is output,
The CPU 6 determines whether the count value input from the time counter 7 every moment has reached a second specified number preset by the CPU 6. This second specified number is a value corresponding to the tape length required to apply fade-out processing to the recording end of tape 1. In FIG. 2, this value corresponds to the count number of the counter 7 necessary to determine position C).

When the count value reaches the second specified number (count value = second specified number), the CPU 6 first sends a fade-out start signal to the fade-out terminal a of the fade-out circuit 9 and the bias terminal to perform the fade-out process. A further inverted bias signal is output to b.

Furthermore, the CPU 6 has a fade-out circuit 9.
Almost simultaneously with sending the fade-out start signal and bias signal (fade-out enable signal), a rewind search stop signal and a playback start signal are supplied to the control circuit 5. As a result, tape 1
The tape drive unit 4 temporarily stops at position C in the recordable area A, and then runs in the playback state.

Next, a specific circuit example of the fade-out circuit 9 is shown in FIG. 3, and fade-out processing will be described. In this figure, the same parts and parts as in FIG. 1 are indicated by the same reference numerals. _Q1 to _Q4 are transistors,
C ₁ and C ₂ are capacitors, R ₁ is a resistor, and 20 is an oscillation circuit.

First, the operation of the fade-out circuit 9 in the recording mode will be explained.

In the recording mode, as is clear from the above, only a bias signal (a high level signal) is supplied from the CPU 6 to the bias terminal b, and the potential of the fade out terminal a is at a low level. As a result, in this recording mode, transistor Q ₁ is off, Q ₂ is on, and Q ₃ is off.
Therefore, the base potential of the transistor Q ₄ rises in accordance with the charging time constant of the resistor R ₁ and the capacitor C ₂ , operating the oscillation circuit 20 and causing an erase current to flow through the erase head 2 .

Next, when in fade-out mode, CPU6
, a bias signal is supplied to the bias terminal b, and a fade-out start signal (high level signal) is supplied to the fade-out terminal a. the result,
In this fade-out mode, the transistor
Both Q ₁ and Q ₂ are turned on, and transistor Q ₃ is turned off. Therefore, the base potential of transistor Q ₄ is
It rises in accordance with the charging time constant of the resistor R ₁ and the capacitors C ₁ and C ₂ , operates the oscillation circuit 20 , and causes the erase current for fade-out to flow through the erase head 2 .

By the way, in FIG. 3, since the relationship between the capacitors C ₁ and C ₂ is C ₁ >> _{C 2} , the rise state of the erase current in the fade-out mode is gradual. Therefore, the sound recorded on tape 1 is
Unlike in the recording mode, the data is gradually erased (fade out).

Next, using the flowchart in Figure 4,
The operation of the CPU 6 will be further explained.

First, in step S1, it is determined whether or not a tape end detection signal is supplied from the tape end detection device 8. When the tape end detection signal is supplied, the process advances to step S2.

In step S2, in response to the input of the tape end detection signal, the high level bias signal that had been output up to that point to the bias terminal b of the fade-out circuit 9 is inverted and output. As a result, no erase current is supplied to the erase head 2.

In step S3, the selection switch 12 is turned on and it is determined whether or not a fade-out selection signal is being supplied. If it is not selected, no further operation will be performed, and after the scheduled time has elapsed, the tape drive device 4 will be stopped based on a stop signal output from the tape end detection device 8 using a well-known method. On the other hand, if it is selected, step S4
Proceed to.

In step S4, a rewind search signal is output to the control circuit 5, and a clear signal is output to the time counter 7. As a result, as described above, the tape 1 is rewound from the end E while being counted.

In step S5, it is determined whether or not the recording end detection signal is supplied from the signal detection circuit 10. If supplied, the process advances to step S6.

In step S6, the count value at the time when the recording end detection signal is supplied, out of the count values inputted every moment from the time counter 7, is compared with a first specified number predetermined by the CPU 6.
As a result, if the count value exceeds the first specified number, it is assumed that the recording has ended before the end point D of the recordable area A, and no fade-out processing is performed.
Proceed to step 7.

In step S7, a rewind search stop signal is output to the control circuit 5. As a result, as described above, the tape drive device 4 stops rewinding the tape 1. As described above, if the fast forward command signal is supplied to the control circuit 5 together with the rewind search stop signal in step S7, the tape 1 can be completely wound again.

Next, in step S6, the count value is set to the first
If it is determined that the number is less than or equal to the specified number, then the process advances to step S8.

In step S8, a clear signal is output to the time counter 7. As a result, the counter 7 starts counting up again.

In step S9, it is determined whether the count value input from the counter 7 every moment has reached the second specified number predetermined by the CPU 6. Then, when the count number reaches the second specified number, the process advances to step S10.

In step S10, a fade-out start signal is output to the fade-out terminal a of the fade-out circuit 9, and a high-level bias signal is output to the bias terminal b. At the same time, a rewind search stop signal and a playback start signal are output to the control circuit 5. As a result, as described above, the tape 1 is temporarily stopped from rewinding at position C in the recordable area A by the operation of the tape drive device 4, and then enters the playback state, where the fade-out process is performed. .

Note that the subsequent stopping of running of the tape 1 at the end E is the same as described in step S3 above, and after a predetermined time has elapsed since the drive of the tape 1 has stopped, the tape end detecting device 8 sends a message to the tape drive device 4. This will be done based on the stop signal supplied to.

(Effects) As is clear from the above description, in the present invention, for example, in the recording state, when the entire song cannot be recorded to the end of the recordable area on the tape,
In other words, only when recording to the end of the tape,
This has the advantage of being able to detect this and automatically apply fade-out processing to the end of the recording.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an automatic fade-out device for a tape recorder according to the present invention, and FIG.
The figure is a plan view showing the vicinity of the end of the tape to explain the operation in Figure 1, Figure 3 is a specific circuit diagram showing an example of a fade-out circuit, and Figure 4 is a flowchart to explain the operation of the CPU. It is. DESCRIPTION OF SYMBOLS 1...tape, 2...erasing head, 3...recording/reproducing head, 4...tape drive device, 5...control circuit, 6...
CPU (centralized command unit), 7...Time counter, 8
...Tape end detection device, 9...Fade out circuit, 10...Signal detection circuit, 11...Reproduction circuit, 12
...Selection switch.

Claims (1)

[Claims] 1. Tape end detection means that detects the end of the tape in the recording state and outputs a tape end detection signal, outputs an erase stop command signal in response to the tape end detection signal, and outputs a tape rewind search signal. means for stopping supply of an erase signal to the erase head based on the erase stop command signal; means for rewinding the tape using the rewind search signal; means for detecting and outputting a recording end detection signal; and whether or not the recording end detection signal is input within a first time period for rewinding a scheduled length corresponding to at least the length of the leader tape from the end of the tape. means for detecting whether the first
If the recording end detection signal is not input within the first time period, at least a rewind search stop signal is output, and if the recording end detection signal is input within the first time period, the tape schedule is further output. continue rewinding a second time corresponding to the length;
Thereafter, means for outputting a fade-out enable signal, a rewind search stop signal, and a playback start signal, respectively, and stopping rewinding of the tape in response to the rewind search stop signal and playback start signal,
An automatic fade-out device for a tape recorder, comprising means for setting the tape to a playback state, and fade-out means for supplying an erase signal for fade-out to the erase head based on the fade-out enable signal.