JPH10162454A - Tape transfer machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To unnecessitate discrimination of a cassette and detection of the tape remaining amount by detecting only the rotational speed of a supply reel and controlling the speed of a driving means for a take-up reel so that the rotational speed of the supply reel becomes a specified set speed. SOLUTION: When the speed of the supply reel 13 which is detected by a sensor 14, is not more the preset rotational speed, a motor 17 is accelerated by a controller circuit 16. When the speed is faster than the rotational set speed, the motor 17 is decelerated by the controller circuit 16. When it is detected as the rotational set speed, the control is made so as to keep the speed of the motor 17 at that time. When the tape is transported and attained around the tape end while thus keeping the rotational speed of the supply reel 13 to the rotational set speed, the tape speed Vt around the tape end is shown as Vt=D×π×Ws (D is diameter of a hub, Ws is rotational speed of the supply reel), independently of the length and thickness of the tape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus using a magnetic tape, for example, a tape transport apparatus (for example, a video tape recorder) (international patent classification G11B 27).
/ 10), which is particularly characterized by fast-forward transport in which the tape is fast-forwarded to the end of the tape.

[0002]

2. Description of the Related Art When a tape in a tape cassette is fast-forwarded to the end of the tape, the diameter of the hub around which the tape is wound, the tape length, and the tape thickness differ depending on the type of tape cassette. Discriminates the type of tape cassette that has been transported, detects that the tape being transported has reached the end using the constants unique to the tape cassette, and sets the take-up reel to a safe speed that does not damage the tape and the device. It has been practiced to reduce the winding speed.

When discriminating this tape cassette, for example, as shown in US Pat. No. 4,398,300, the tape is transferred at a known speed, and the rotation speed of the tape supply side reel (hereinafter referred to as a supply reel) detected at that time and the take-up speed are taken up. The ratio of the rotation speed of the side reel (hereinafter referred to as a take-up reel) is calculated, and the calculated value based on the square of the calculated value is compared with a constant corresponding to the type of the tape cassette stored in the memory. A method for determining a tape cassette is known.

Further, as disclosed in Japanese Patent Application Laid-Open No. 53-6004, the ratio of the rotation speed of the supply reel to the rotation speed of the take-up reel is calculated, and the tape position is detected using a constant corresponding to the type of tape cassette. There is a known way to do this. According to these methods, when the tape is fast-forwarded, if a stop signal is not input while the tape is being transported to the end, the tape is transported at a high speed to near the end, and then the tape is transported to the tape end at a low speed. Thus, damage to the tape can be prevented.

FIG. 6 shows a conventional technique. After the discrimination of the tape cassette is performed by the above method, the sensor 1,
The speed of the take-up reel 3 and the supply reel 4 is measured by the sensor 2, and the tape position is calculated based on the speed ratio. And, while the tape remains much to the end, that is,
6A and 6B, the take-up reel 3
7 is driven at high speed (V1) as shown in FIG. 7, and in the state of FIG. 6C near the end, the tape speed at the end of the tape can be safely stopped by the brake means (V1).
t), the reel speed of the take-up reel 3 is set to a low speed (V
The speed is reduced to 2) to prevent tape damage and device damage.

Further, for example, in the case of the tape cassettes TC-40 and TC-30 of the VHS system, the cassette cannot be distinguished by a single measurement depending on the state of the winding diameter. The cassette is discriminated by comparing the rate of change of the diameter or the state of the winding diameter at two or more locations during transfer, a constant corresponding to the cassette is determined, and the speed of the take-up reel near the end is determined by the above method. Had been lowered.

The tape cassettes TC-40 and TC-3
Reference numeral 0 denotes a small tape cassette called a C cassette. The C cassette 5 can be used in the same manner as a normal tape cassette in a state where it is set on a C cassette adapter 6 as shown in FIG. In this state, one hub 7 of the C cassette 5 is directly connected to the reel stand 11 of the apparatus, while the other hub 8 is reduced in speed through the conversion gear 10 in the C cassette adapter 6 and connected to the reel stand 11. Is done.

For this reason, the actual number of rotations of the hub 8 and the number of rotations of the reel base 11 do not match, and the speed ratio of each reel does not directly indicate the state of the tape in the cassette. It was necessary to take an appropriate method.

[0009]

As described above, the discrimination of the tape cassette is performed, and while using the constant peculiar to the cassette,
In the method using the rotation speed ratio between the supply reel and the take-up reel, it is necessary to simultaneously monitor the speeds of the two reels. In addition, the discrimination of the cassette is necessary, and the cassette cannot be specified instantaneously depending on the cassette type and the winding diameter, so that it takes a very long time to discriminate. In addition, a large calculation and a calculation processing unit were required to record the constants specific to the cassette necessary for the determination, measure the rate of change in the winding diameter, and compare with the constants specific to the cassette. .

[0010]

In order to solve the above-mentioned problems, a tape transfer device according to the present invention detects only the rotation speed of a supply reel and adjusts the rotation speed of the supply reel to a set constant speed. By controlling the speed of the drive means of the take-up reel, cassette discrimination, speed detection of the take-up reel, tape position detection, and calculations and calculation means for them are unnecessary.

[0011]

DETAILED DESCRIPTION OF THE INVENTION A tape transfer device according to a first aspect of the present invention is a tape transfer device for transferring a tape between two reels. The tape transfer device is characterized by controlling the drive means of the take-up reel so that the rotation speed of the take-up reel is adjusted to only the supply side, eliminating the need to detect the end of the cassette by discriminating the cassette and detecting the remaining amount of tape. It is possible.

According to a second aspect of the present invention, when the rotational speed of the supply reel is lower than the set speed, the drive unit is accelerated, and when the rotational speed is the same as the set speed, the state of the drive unit is maintained. When the speed is higher than the set speed, control is performed so that the driving means is decelerated, thereby enabling high-speed tape transfer.

In the tape transfer device according to the third aspect of the present invention, after the drive means is once decelerated, control is performed so as not to be accelerated again. By preventing acceleration and deceleration of the take-up reel driving means, gentle acceleration and deceleration are realized, thereby making it possible to prevent noise and tape damage.

(Embodiment 1) An embodiment of the present invention described in claims 1 and 2 of the present invention will be described below with reference to FIGS.

FIG. 1 shows the state of the take-up reel 12 and the supply reel 13 during the fast-forward. Reference numeral 15 denotes a tape which is housed in a cassette (not shown), and has a different length and hub diameter depending on the type of the cassette. Each reel 1
Reference numerals 2 and 13 are respectively connected to a reel base of the apparatus. The sensor 14 is a means for detecting the speed of the supply reel 13 and is a photosensor having a built-in LED light-emitting unit. The three LEDs (not shown) attached to the supply reel base block the LED light inside the reel base as the reel base rotates. The rotation speed of the reel is detected by measuring the time of the interruption interval. Reference numeral 16 denotes a controller circuit for controlling the transfer of the tape, which is constituted by a microprocessor. Reference numeral 17 denotes a motor for driving the take-up reel.
Alternatively, the speed is controlled to be maintained.

The speed of the supply reel 13 is detected by a sensor 14, and when this speed is lower than a preset rotation speed, a motor 17 is accelerated by a controller circuit 16. If the rotation speed is higher than the set rotation speed, the motor 17 is decelerated by the controller circuit 16. In the case of the set rotation speed, control is performed so as to maintain the speed of the motor 17 at that time.

FIG. 2 shows a case where the tape is transported and reaches near the end of the tape while maintaining the rotation speed of the supply reel 13 at the set rotation speed. The tape speed Vt near the end is always the speed shown by the following expression regardless of the tape length and thickness.

Vt = D × π × Ws where D is the diameter of the hub and Ws is the rotation speed of the supply reel.

The rotation of each reel base is stopped when necessary by a known brake means (not shown). However, a certain time is required until the brake means operates and the reel stops. Yes, the tape is about to be unwound from the supply reel until the reel stops. At this time, the tape speed that can be safely stopped is a value specific to the brake means, and can be experimentally established. Therefore, in the present embodiment, since Ws is set to a safe speed, the tape speed Vt always takes a safe value satisfying the above expression at the tape end portion as shown in FIG. It becomes possible. Further, this action is valid for cassette tapes of any length and thickness as long as the hub diameter is constant, and it is not necessary to determine the cassette.

Here, a method for detecting the end of the tape will be described. In the case of a cassette tape,
There is a leader tape made of a transparent material having a length determined by a standard, and an end sensor is detected by an optical sensor (not shown). Therefore, if the tape speed is faster than the time during which the brake acts, the tape cannot be stopped within the range of the leader tape, and the tape is still wound up without the tape to be fed out, resulting in tape damage, destruction of the device, and the like.

In the present embodiment, the method of transporting the tape in the direction of the arrow in the figure has been described. However, when the tape is transported in the opposite direction, the supply reel and the take-up reel are set opposite to each other.
What is necessary is just to detect the speed and reverse the reel to be within the set speed.

FIG. 3 shows the rotation speed of the take-up reel 12 and the change during the tape transfer in this embodiment. When the radius of the take-up reel 12 is small, the take-up speed is accelerated because the take-up amount of the tape is small. As the radius of the take-up reel 12 increases, the take-up speed is controlled so as not to be accelerated but to be gradually reduced. Therefore, the tape is transported at a high speed during winding, and is reduced to a safe speed near the end.

Next, the case of the C cassette will be described. In FIG. 4, in the VHS standard, Wc2 ≒ 0.56 × Wc1, where Wc1 is the supply reel speed, and Wc2 is the speed of the reel base of the recording / reproducing apparatus reduced by the adapter.

When the tape is fed in the direction of the arrow in FIG.
The tape speed at the end of the tape is as follows: Vct = Dc × π × Wc1 ≒ Dc × π × Wc2 / 0.56 where Vct is the tape speed, Dc is the diameter of the hub, and Wc2.
Is the speed of the reel base of the recording / reproducing device reduced by the adapter.

The diameter of the hub stipulated by the VHS standard is φ26 for the thin hub, and the diameter of the hub of the right reel in FIG. 4 of the C cassette is about φ14.

If Dc = φ14 in the above equation, Vct = φ25 × π × Wc2 ≒ φ26 × π × Ws (Wc2 = Ws) Therefore, it is not necessary to distinguish between the narrow hub cassette and the C cassette.

When the tape is transferred in the direction opposite to the direction of the arrow in FIG. 4, the diameter of the hub on the left side in FIG.
Since it is (≒ φ26), it is not necessary to distinguish it from the narrow hub cassette.

(Embodiment 2) An embodiment of the invention described in claim 3 of the present invention will be described below with reference to FIG.

FIG. 5A shows a change in the take-up reel speed during the tape transfer in the above-described embodiment.

If the speed detection of the supply reel does not include an error, the speed change of the take-up reel becomes gentle as shown in the figure. However, in the normal case, the speed detection includes an error. As shown in ()), when the speed of the take-up reel is fine, the speed gradually decreases while repeating acceleration and deceleration. In the present embodiment, as shown in FIG. 5C, once deceleration is performed, control is performed so that acceleration is not performed. By performing such control, it is possible to prevent beat noise, tape damage, and the like due to small acceleration and deceleration.

It is to be noted that, besides the above description, the acceleration / deceleration command to the take-up reel drive means may be provided at fixed time intervals at which no beat is generated, or when the rotation speed of the supply reel is compared with the set speed. The same control as that shown in FIG. 5C can be performed by providing a constant threshold level and issuing an acceleration / deceleration command.

[0032]

As described above, according to the tape transfer device of the present invention, by controlling the rotation speed of the supply reel to a set constant speed, cassette discrimination and tape remaining amount detection (terminal end) (Neighborhood detection) is unnecessary, and reel speed detection during tape transfer is only on the supply side, so it is simple and inexpensive, and high-speed tape transfer is possible by driving the take-up reel at high speed during winding. In addition, it is possible to provide a safe tape transfer device free of hum, tape damage, and the like.

[Brief description of the drawings]

FIG. 1 is a plan view showing an outline of a tape transfer device according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the vicinity of the end of the tape of the tape transport device according to the first embodiment;

FIG. 3 is a diagram showing a change in a take-up reel speed at the time of tape fast-forward according to the embodiment;

FIG. 4 is a plan view and a side view showing a state where a C cassette is loaded in a C cassette adapter.

FIG. 5 is a diagram illustrating a change in a take-up reel speed at the time of tape fast-forward according to a second embodiment of the present invention.

FIG. 6 is a plan view showing an outline of a conventional tape transfer device.

FIG. 7 is a diagram showing a change in a take-up reel speed at the time of tape fast-forward in the conventional tape transfer device.

[Explanation of symbols]

 12 take-up reel 13 supply reel 14 sensor 15 magnetic tape 16 controller circuit 17 motor

Claims (3)

[Claims] In a tape transfer device for transferring a tape between two reels, a rotation speed detecting means for a supply reel on a side where the tape is sent out, a driving means for driving a winding reel on a side where the tape is wound, and Control means for controlling the driving means, and brake means for stopping the rotation of each reel, and when the tape is fast-forwarded, the rotation speed of the supply reel is predetermined so that the brake means can safely stop each reel at the end of the tape. A tape transfer device for controlling the driving means so as to be within a set speed. 2. When the rotation speed of the supply reel is lower than a set speed, the driving means is accelerated.
2. The tape transfer device according to claim 1, wherein the state of the drive unit is maintained, and when the speed is higher than the set speed, control is performed so that the drive unit is decelerated. 3. When the rotation speed of the supply reel is higher than a set speed, control is performed to decelerate the driving means, and after deceleration is performed, control is performed so as not to accelerate again.
The tape transfer device as described in the above.