JPH0213382B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape speed control system that uses low power to feed a tape at a constant speed.

In the conventional method of feeding a tape at a constant speed, a rotatable pinch roller is generally pressed against a capstan shaft rotating at a constant rotational speed, and the tape is fed at a constant speed by the press-contact portion.

However, when the pinch roller is brought into pressure contact with the capstan shaft in this manner, there is a problem in that power consumption increases due to the mechanical load caused by the pressure contact force.

The present invention provides a tape speed control system that can reduce power consumption as described above and stably feed the tape at a constant speed.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, a tape 4 is wound tightly around a supply reel 1a and a take-up reel 1b, and is fed through a guide roller 2 in the direction of the arrow. When the supply reel 1a and the take-up reel 1b are stationary, the take-up reel 1b is moved by a motor (not shown).
The tape speed detecting roller 3, which lightly contacts the tape 4 and rotates at a speed corresponding to the tape speed, detects the tape speed at a reference constant speed V (cm/cm/cm).
sec) is detected. At this time, the rotation speeds of the supply reel 1a and the take-up reel 1b are respectively n ₀ (rpm),
When n ₁ (rpm) and the respective radii including the winding diameter of the tape 4 are r ₀ (cm) and r ₁ (cm), the following relationship holds true.

n ₀ = V×60/2πr ₀ ………(1) n ₁ = V×60/2πr ₁ ………(2) π(r ₀ ² − r ₁ ² )=K(const)……(3 ) From the above equations (1) to (3), 1/n ₀ ² + 1/n ₁ ² = (2π/V×60) ² K/π=C=
const……(4). That is, as shown in equation (4), 1/n ₀ ² +1/n ₁ ² is always constant.

Therefore, using this 1/n ₀ ² + 1/n ₁ ² as a reference value, the rotational speeds n ₀ ′ (rpm) and n ₁ ′ (rpm) of the supply reel 1a and the take-up reel 1b are measured from now on. , 1/n ₀ ′ ² + 1/n ₁ ′ ² and the aforementioned 1/n ₀ ² + 1/n ₁ ² , the motor that rotates the take-up reel 1b is controlled, and the running speed of the tape 4 is set to V (cm /sec).

Figure 2 shows a flowchart of the above process.
First, the tape speed detection roller 3 detects that the standard constant speed V (cm/sec) has been reached, and then
Measure n ₀ and n ₁ and find 1/n ₀ ² +1/n ₁ ² =C. Using this C as a reference value, the rotational speed of the supply reel 1a and take-up reel 1b will be measured from now on.
Measure n ₀ ′ and n ₁ ′ and find 1/n ₀ ′ ² +1/n ₁ ′ ² =C′. Then, calculate the difference C-C'=ΔC between C and C', and calculate the difference C-C'=ΔC.
and the allowable error value δ, and if -δ<ΔC<δ, no control is applied to the motor, and if -δ>ΔC or ΔC>δ
If so, the motor is controlled accordingly to bring the running speed of the tape 4 close to the V (cm/sec).

As described above, according to the present invention, when running a cassette tape at a constant speed, for example, the type of cassette tape (C-46, C-60, C
-80, C-90, etc.), 1/n ₀ ² + 1/n ₁ ² = C is always constant for each cassette tape, so the tape speed can be easily controlled to be constant. Furthermore, since there is no mechanism for feeding the tape by press-contacting the pinch roller and the capstan shaft as in the conventional example, the tape can be run at a constant speed with low power consumption.

[Brief explanation of drawings]

FIG. 1 is a plan view of an embodiment of the present invention, and FIG. 2 is a flowchart thereof. 1a... Supply reel, 1b... Take-up reel, 2... Guide roller, 3... Tape speed detection roller, 4... Tape.

Claims (1)

[Claims] 1. The number of revolutions n ₀ of the supply reel of the tape running at a constant speed and the number of revolutions n ₁ of the take-up reel are measured to calculate 1/n ₀ ² + 1/n ₁ ² ; , said 1/n ₀ ²
+ 1/n ₁ ² is used as a reference value, and the rotation speed n ₀ ′ of the supply reel and the rotation speed n ₁ ′ of the take-up reel are measured at any time to calculate 1/n ₀ ′ ² + 1/n ₁ ′ ² . , said 1/n ₀ ′ ²
+1/n ₁ ′ ² and the above-mentioned 1/n ₀ ² +1/n ₁ ² are compared, and the tape drive motor is controlled according to the error, thereby running the tape at the constant speed. , a tape speed detection roller that lightly touches the tape and rotates at a speed corresponding to the tape speed detects the tape speed from a stationary state to the constant speed, and in the constant speed state, performs the above calculation. A tape speed control method, characterized in that it is configured to control tape speed.