JPS5977658A - Device for controlling driving of tape - Google Patents

Abstract

PURPOSE:To execute quick traverse and rewinding almost at a fixed speed by coupling a deceleration controlling device with a speed controlling device and by changing the objective control value of a tape speed controlling part by a high speed tape feeding signal, an output of a tape end terminal detecting part, and a low speed tape feeding signal. CONSTITUTION:A rotor rotating magnetic field detecting signal detected by a hole element H1 is applied to a driving circuit D1 through a voltage controlling amplifier (VCA) A1 and the output of the driving circuit D1 is applied to a reel motor winding W1 through a switch S1. The output of the hole element H1 is applied as a revolution signal phiT1 to the tape end terminal detecting part 10 and the tape speed fixing controlling part 11, and the detecting part 10 detects the approach of the tape end terminal, forms high and low speed signals H/L and sends the formed signals to the controlling part 11. The controlling part 11 generates a speed controlling signal V fixing the tape speed and applies the signal V to the gain controlling input of the VCA A1. Consequently, the turning speed of the reel motor can be adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape movement control device for a cassette recorder or the like.

What's the problem? In a cassette tape recorder, the start and end of the cassette tape are fixed to the reel hub of the cassette, so the shock to the tape at the end of winding on the wall of 1% fast forward/@backward is extremely high. This can sometimes cause damage to the tape. For this reason, a deceleration control device 1 is provided to detect when the winding end is near and to decelerate the tape running.

(Continued on next page.) This deceleration control device has a constant rotation speed ratio between the supply reel and the take-up reel at approximately 9 o'clock when the tape is wound, which is determined by the maximum tape winding diameter and the reel hub diameter for cassettes of various tape lengths. By using this fact, the proximity of the end of the tape is detected and the speed is decelerated.

The above-described tape end detection method is valid for cassettes C60, C90, and c12o with tape lengths of 60 minutes, 90 minutes, and 120 minutes, but for cassettes with lengths other than the above, such as C46 and C50, Since the reel rotation speed ratio at the end of the tape is smaller than standard, the deceleration control circuit becomes inoperable.

For this reason, a deceleration control device having a learning ability that can perform deceleration control for all types of cassettes has been proposed.

This learning ability deceleration control device detects the maximum value (or minimum value) of the reel rotation speed ratio corresponding to the end of the tape for each cassette and always stores this value.

On the other hand, by keeping the tape running speed constant during fast forward 97 rewinding, it is possible to wind the tape in a uniform time without being affected by variations in tape running load for each tape set.
It also performs cue/review playback to detect inter-song signals,
This is convenient when locating the beginning of a song to be played.

Conventionally, the deceleration control device that waits for the above-mentioned learning ability and the speed control device that keeps the tape speed constant for fast forwarding 97 and rewinding were provided separately, so the reel motor control i@1 circuit was extremely complicated. there were.

OBJECTS OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to combine a deceleration control device and a speed control device, and to simplify the circuit configuration by combining the deceleration control device and the speed control device.

Summary of the Invention The tape drive open side 1 device according to the present invention includes a tape end detection section that detects the approach of the tape end during fast forwarding or rewinding, and a high speed tape feed signal and a low speed tape output from the tape end detection section. By providing a tape speed control unit whose control target value is changed by a feed signal, fast forwarding or rewinding is performed at a nearly constant tape speed,
Near the end of the tape, high-speed tape feeding is switched to low-speed tape feeding.

Embodiments Below, embodiments in which the present invention is applied to a tape recorder will be described. Figures 1 to 5 are diagrams for explaining the principles of tape speed deceleration control and constant tape speed control for fast forwarding υ/rewind when approaching the end of the tape, and Figure 1 shows FIG. The tape recorder of this embodiment includes dedicated direct-coupled reel motors that drive the supply reel and take-up reel, respectively. As shown in Figure 1, during rapid traverse, the supply reel (1) and take-up reel (2)
A magnetic tape (3) wound around the magnetic tape (3) is run in the direction of arrow FF. The supply reel shaft and the take-up reel shaft each have a rotation speed n3.
If it rotates at S nT and the tape winding diameters on reels (1) and (2) at that time are respectively rs1 rTS, then the ratio nB
/nT is equal to the ratio rT/rs. Ratio rT/ rB &
Maximum at about 9 o'clock when one tape is wound, which is equal to maximum tape winding diameter/reel hub diameter, C60, C90 and Cl2
In the case of a cassette of O, the value of nB/town is approximately 2.2, so as shown in the graph of FIG. Change. Note that the horizontal axis of the graph in FIG. 2 is normalized for cassettes of each tape length. Tape length is 46
When using the cassette C461, nB/nT increases as shown in curve B in FIG. 2, but its maximum value is smaller than 2.2. Therefore, the maximum value of nS/nT is detected and memorized, and when fast forwarding (rewinding)
When 8/nT approaches the specific maximum height of the core cassette, deceleration braking is applied. That is, when the rotational speed of each reel at the end of the tape is divided by nS' and nT', the rotational speed ratio is set to switch to slow feeding when the following conditions are satisfied. k in the first equation is a correction value taking into account the necessary margin for applying deceleration braking, and the right side of the first equation is a slightly smaller value than 2.2 for tapes such as C60,090.

Specifically, as the change curve of the reel rotation speed ratio in Fig. 6, in the latter half of tape fast forwarding (after T/2 on the horizontal axis), ns
Assuming a change curve of /nT, in the first half, the reciprocal nT/n
A change curve of B is assumed.

If the tape position P when fast forwarding is started is in the first half of the tape, the initial value a1 of the ratio nT/nB at that time is stored in the memory. Data in this memory is not updated. If this is the case, the first half of the tape is a, as shown in Figure 6.
This is because l is the maximum value.

The same value as al appears in the measured value ns/nT on the latter half of the tape. The tape is fast-forwarded to a point P' where ns/nT matches al, and after that the tape is switched to a low speed and the memory contents are changed to the measured value nB/
It is compared with nT, and new measured values (larger values) are successively rewritten as stored data.

The value a2 when the end of the tape is reached in a low speed running state is the maximum value of the reel rotation speed ratio ns/nT to be detected. Through this learning process, the maximum value a2 of the rotation speed ratio is stored in the memory by one fast-forward operation, and from the next fast-forward operation, the maximum value a2 of the rotation speed ratio is stored in the memory by comparing a2 and the measured value of ns/nT. , the proximity of the end of the tape is detected, and based on this, deceleration braking is applied to the fast forward as shown in the tape speed graph of FIG. 4, and the tape speed is changed from FF1 to FF2.

Note that the value of the maximum value a2 is stored including the correction value k of the first equation.

Various techniques have been proposed for constant fast-forward multi-speed control, but in this embodiment, the number of revolutions of each of the supply reel (1) and take-up reel (2) is %u n5 +n'l
” is controlled so that it becomes a predetermined value (constant value).

Figure 5 is a graph showing changes in the sum n5+nT when the traveling speed is completely constant, and this value does not change by a large 11]. Therefore, if the reel motor is controlled so that nB + nT is constant, the tape speed can be regarded as approximately a constant value.

Next, FIG. 6 is a block diagram schematically showing a tape drive control device according to the present invention, and FIG. 7 is a more detailed circuit diagram.

The reel motor of this embodiment includes a sinusoidally magnetized rotor and two-phase motor windings with a 90° phase shift. Changes in magnetic flux linkage of each winding are detected by a Hall element, and each winding is 5in2+Co52 (constant value) by passing a drive current that changes with sine and cosine functions that are in phase with the change in magnetic flux linkage.
This is a two-phase 90° winding sine wave drive type brushless motor designed to obtain a rotational torque of . For simplicity, FIG. 6 shows a drive circuit for one of the two phases of the take-up reel motor.

In FIG. 6, the sinusoidal rotor rotating magnetic field detection signal detected by the Hall element H1 is detected by the voltage controlled amplifier (VCA).
) is applied to the drive circuit D1 via AI, and the output of this drive circuit is applied to the motor winding W1 via switch S1. The switch S1 is used to cut off the drive current of this reel motor and put it in a free rotation state. In order to cause this reel motor to function as an electromagnetic brake, a short-switch switch SW1 is further provided to short-circuit the winding wi.

The drive circuits for the other winding W2 of the take-up reel motor and the two-phase windings W5 and W4 of the supply reel motor are shown in FIG. 7 and are the same as those in FIG. 6.

The output of the Hall element H1 is used to detect the rotational speed of the supply reel (1) and the hemp reel (2).

This output is waveform-shaped by the differential amplifier F1 and then given as a rotation signal φT1 to the tape end detection section (101 and tape speed constant control section old). As shown in FIG. The output of the Hall element H2 of the other phase of the reel motor (90' phase shift with respect to Hl) is also given to the system controller (100 degrees φT2) through the difference S amplifier F2 as shown in FIG.

The system controller receives the rise and fall of the rotation signals φT1 and φT2 as rotation speed information, so
When the rotor is magnetized with four poles, rotation speed information of 8 waves each for φT and φT2, 16 waves in total, is obtained per rotation of the reel motor. In addition, the outputs of the Hall elements H3 and H4 of the supply reel motor are similarly connected to the differential amplifiers F5 and F4.
are given to the system controller (121) as rotation signals φs1 and φs2.

Based on the rotation signals φT4, φ1□, φ81, and φ82, the tape end detection section (lO) detects the approach of the tape end according to the principle described above, and forms a high/low speed signal H/L. This speed number is given to the constant tape speed control section 01). This control section (old) uses rotation signals φT1 to φ8.
2, the speed control signal V to keep the tape speed constant is generated as a digital value, and this speed control signal V is controlled for the high speed running speed FFI and the low speed running speed FF2 according to the speed signal H/L. It has a function to switch to a value.

The speed control signal (1) is converted into an analog control signal by a D/A converter (131) and then applied to the gain control input of each VCA (Al-A4).This controls the amplitude of the input signal of each VCA. , the rotational speed of each reel motor is adjusted.

The system controller Oz is provided with fast forward, rewind, and forward motors No. 46 FF', REW, and FWD, and depending on these mode signals, turns on/off switches 81 to 81 for the drive current of each reel motor. S4 and winding short switches SW1 to SW4 control signals S open, T
Open, S-short, and T-short are respectively formed.

These control signals cause the take-up reel motor to rotate at a plateau during fast forwarding, for example. On the other hand, the supply reel motor switches S6, S4, SW3 during high-speed rapid forwarding.
, when SW4 is turned off and rotates 7 times and switched to low-heavy feed, switches SW6 and SW4 are turned on and motor windings W5 and W4 are short-circuited, and as an electromagnetic pulley. -b is created, which results in a quick speed-up.

Each switch S1 to S4, S during fast forwarding υ (high speed and low speed)
The operations of W1 to SW4 are as shown in the table below.

When rewinding, the operation of each switch is opposite to that of the jacket.

Next, the system controller (121) including the tape end detection unit dll and tape speed constant control unit (121) shown in
The data processing procedure in F is explained with reference to FIGS. 8 and 9. FIG. 8 is a flowchart showing the procedure for detecting the tape end, and FIG. 9 is a flowchart showing the procedure for controlling the tape speed.

In FIG. 8, in step (!OJ 121), the reel rotation speed ratio ns/nT is read and the measured value is compared with the memo IJ- value. In other words, since 16 waves of rotation signals are obtained per reel rotation, the supply reel (S side) is generated per rotation (16 waves) of the take-up IJ reel (T side).
The closer to the starting end side of the 0 tag that detects how many rotations (or side waves are generated), the smaller the number of waves on the S side generated in one rotation on the T side.

Step 06) In (27), on the other hand, the reel rotation speed ratio nT/nS is read with the S side as a reference and compared with the average value. The closer to the deep end cell side, the smaller the wave number of T Ill generated in one rotation on the S side becomes.

When the memory answer is nRBF (corresponding to the wave number at the time of decelerating the tape), step (by determining zO, if the wave number of S 11!+ ≦ 11 OF, then 17 Tesop C 5) at that time The S-side waveform of is written into memory as nREF. Tsuma system depth (20-123
In the + process, a minimum of 11 wards of nB/nT are detected, which corresponds to the town/n area in the first half of the tape in Figure 6.
This corresponds to detecting the maximum value of s.

Meanwhile, step c! Wave number on T side ≦11 at 44” cut of 0
If it is RFiF, step (- means T' 1
ii: The wavenumber of j is written into memory as nRBF. In other words, in the process from Step 4 to -Ten, nT/n
The detection of the minimum value of B has been carried out, which corresponds to the detection of the maximum value of H8/nT over the life of the tape in FIG.

During fast forwarding (FF), the process of step C (20~It!8J) is mainly performed to detect the third end of the tape, and the process continues until the measured value reaches the minimum value of nREF stored in the memory. , the speed signal becomes "H" in step (25), which is branched from step Q force.Also, when the measured value reaches "F", the speed signal changes from step (27) through the steps to "L".
becomes. During rewinding (REW), steps 7o) to (23) are mainly performed to detect the beginning of the tape, and similarly, the speed signal is "H" until the measured value reaches the minimum value of nRBF, and the exposure is continued. After that, it becomes L''.

Step (24) in Figure 8 and the "No" branch in step 8 are used to store the initial value of the reel rotation speed ratio (al in Figure 6) at the first half position of the tape during fast forwarding or rewinding. Occurs only once.

In the constant speed control section (old version), as shown in the flowchart 1 of FIG. 9, the reel rotational speeds of °l' 11411 and S III are first detected at the Stellar Prius υ. This detection is performed by, for example, rotating signals φTA, φT2 and φs within a certain period of time.
1, φs2 is done by counting the side waves. Next, step 6 is followed by the step shown in Figure 8 (
c) Determine H/L of the speed signal formed in C31, and if +IH"°, step (l sets the control target value to high speed v14. IIL", step (
In step (1), the target value is set to low speed VL.

During high-speed forwarding, fast forwarding and rewinding are distinguished in step 3!51, and in fast forwarding, the electromagnetic brake of the motor is released on the T side at step j37, and in step j37 for rewinding, the S (regular reel) is The motor's ``electromagnetic'' rake is released.

When switching to low-speed forwarding near the end of the tape, it takes one step and 913 springs (4()) in fast-forwarding, i' (t
The il+ reel motor acts as an electromagnetic brake, and in rewinding, the S l1l11 reel motor acts as an electromagnetic brake.

In the next step (inquiry), the 11th nT+nB of the rotation speed of T side and 81111 is compared with the target value vH or VL,
If the sum is υ larger than the target value, step (V by the 4th edition)
A digital control signal V is generated which reduces the gain of CA (A1-A4). If the sum is smaller than the target value,
A digital control signal that adds the gain of the VCA is generated by step 4. If the sum is equal to the target value, no change in gain is made.

Although the present invention has been described above with reference to preferred embodiments, it can be implemented in various ways other than the embodiments. For example, as the reel motor, in addition to a two-phase 90' winding type brushless motor, a switching type brushless motor, a DC motor, etc. can be used, and a pulse generator or a frequency generator can be used as the reel rotation detection means. As a method of keeping the tape speed constant during fast forwarding/rewinding, in addition to the embodiment, a control method may be used in which the sum of the squares of the supply and take-up reel rotation periods becomes a constant value.

Furthermore, the memory for storing the value of the reel rotation speed ratio at the end of the tape is preferably non-volatile.

Effects of the Invention As described above, the present invention is provided with a tape speed control section that runs the tape at a substantially constant speed during fast forwarding 9 or rewinding, and high-speed tape feeding based on the output of the tape end detection section that detects the approach of the end of the tape. The control target value of the tape speed controller is changed by the signal and the low-speed tape feed υ signal, and fast forwarding or rewinding is performed at a nearly constant tape speed. The rotational speed of the reel motor is controlled by the D/A conversion signal of the digital control output of the tape speed control section so that the tape speed is switched to υ. Therefore, the tape feed speed near the end of the tape can be reduced very easily by changing the control target value of the tape speed control section, so the configuration of the tape drive control system or the software of the data processor included therein can be simplified. can be achieved.

[Brief explanation of drawings]

1 to 5 are for explaining the principle of tape end detection and constant tape speed control of the tape moving device according to the present invention. FIG. 1 is a schematic plan view of a cassette tape, Figure 2 is a graph showing changes in the rotation speed ratio between the supply reel and take-up reel during fast forwarding and rewinding, Figure 6 is a graph showing changes in the reel rotation speed ratio for tape end detection, and Figure 4 is a graph showing changes in the rotation speed ratio of the supply reel and take-up reel during fast forwarding and rewinding. A graph showing changes in tape speed during fast forwarding or rewinding, and Figure 5 is a graph showing changes in the sum of the rotational speeds of the supply reel and take-up reel when fast forwarding or rewinding is performed at a constant speed. It is. FIG. 6 is a block diagram showing the main parts of the tape drive control device according to the present invention, FIG. 7 is a detailed circuit diagram of FIG. 6, FIG. 8 is a flowchart showing the data processing procedure for detecting the end of the tape, and FIG. is a flowchart showing the data processing procedure for constant tape speed control 0 In the symbols used in the drawing, (1)... Supply reel (2)... Take-up reel (3)・Magnetic tape Cl0I... Tape end detection section aυ ・
・・・・・・ Tape speed constant control section (1 ta...
... D/A conversion converter-1 to H4... Hall element ■...... Speed control Ff No. A1 to A
4... ・Voltage control amplifier D1 to D4...
Drive circuit ■~W4... Motor winding. Agent Masaru Ueya Yoshi Tsune Sugiura Shun Award 1st To4 Figure 2”/727.4 c6o, ctyo, cw
. 3rd struggle 4I'4

Claims (1)

[Claims] means for detecting the respective rotational speeds of the supply reel and take-up reel of the tape cassette; means for detecting the rotational speed ratio of the supply reel and the take-up reel based on the detected rotational speed signals; /l, consisting of a memory for storing the rotation speed ratio and a means for comparing the memory contents with the newly detected reel rotation speed ratio, and based on the comparison result, the memory contents are determined to be a larger value or a lower value. updated to a smaller value,
@Finally, the value of the rotation speed ratio corresponding to the tape end position is stored in the memory, and the ratio 1 bite means detects the proximity of the end of the tape during fast forwarding or rewinding, and changes from the high speed tape feed signal to the low speed. It includes a tape end detection section configured to switch its output to a tape feed signal, and
Using the rotation speed detection signal of each reel as input, a digital control signal is generated to keep the tape speed approximately constant during fast forwarding or rewinding. A tape speed control unit for controlling the rotational speed is provided, and the control target value of the tape speed control unit is changed according to a high speed tape feed signal and a low speed tape feed signal from the tape end detection unit. A tape drive controller designed to