JPH0619868B2 - Tape speed setting method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a system for setting a tape speed of a magnetic recording / reproducing apparatus (hereinafter referred to as a VTR).

(Prior art and its problems) In a conventional VTR, when an image of a specific portion is to be played back at an arbitrary time length, for example, a video of 36 seconds at a normal tape playback speed is shortened to 30 seconds. The tape speed is set as follows when playing back or when playing a video for 12 seconds at a normal tape playback speed by stretching it to 15 seconds. In other words, the person who operates the VTR has previously calculated the tape playback time reduction / expansion rate of 36 ÷ 30 = 1.2 or 12 ÷ 15 = 0.8 separately, and a knob called the shuttle dial is used when operating the VTR. It is rotated, and the rotary encoder directly connected to this supplies the pulse output according to the rotation direction and the rotation angle to the tape speed control circuit, and it is displayed whether the tape speed set value has reached the target value. The tape speed is set while visually checking the tape speed value.

Since the conventional method requires such an operation procedure, it is necessary to know in advance the tape speed value to be set by calculation. Further, since the knob of the shuttle dial is rotated by human hands, when the tape speed value is to be set quickly, the knob may be turned too much, which is a troublesome setting. It was

(Purpose) The present invention eliminates these drawbacks and enables the setting of expansion and contraction of the tape reproduction time in a VTR accurately and promptly without interposing a shuttle dial.

(Examples) Examples of the present invention will be described below with reference to the drawings. 1 is a tape running direction and a shuttle dial that is rotated when setting the tape speed, 2 is a rotary encoder that generates a pulse signal depending on the rotating direction of the shuttle dial 1 and the rotating speed, and 3 is a numerical register from 0 to 9 , A keyboard equipped with function keys for setting tape speed values and operation command keys for performing operations, 4 is a counter for counting the number of input pulses from the rotary encoder, 5 is a keyboard 3 An arithmetic circuit that calculates the tape speed value based on the data obtained by operating the numeric keypad and function keys, 6 selects the speed set value by the shuttle operation and the speed set value by the keyboard operation, A speed setting circuit for setting, 7 is a tape for driving a motor so that the tape speed becomes a set value. Degree control circuit, 8 is a capstan motor for running a tape.

This operation will be described below. The usual arbitrary tape speed can be set with the shuttle dial 1. As shown in the previous example, the video for 36 seconds at normal tape playback speed
Considering the case of shortening to 30 seconds and reproducing, "V" using the function key of 3, the numeric key, and the operation command key,
Each key is operated in the order of "3", "6", "÷", "3", "0". The arithmetic circuit 5 arithmetically processes the tape speed value based on the signal sent from each key, and sends the arithmetic result to the speed setting circuit 6. The speed setting circuit 6 switches the data by the shuttle dial 1 and the setting circuit 6 switches the data from the tape speed set by the shuttle dial 1 to the tape speed set by the operation of the keyboard 3, and the result is sent to the tape speed control circuit 7. send. The tape speed control circuit 7 controls the capstan motor 8 according to the capstan control method that is usually performed in the VTR so that the tape speed value is equal to the transmitted tape speed value.

(Effect) As described above, according to the present invention, the setting of expansion / contraction of the tape reproduction time can be performed by providing a simple keyboard.
It can be done accurately and quickly.

[Brief description of drawings]

The figure is a block diagram showing an embodiment of the present invention. 1: Shuttle dial, 2: Rotary encoder,
A keyboard provided with numeral keys 3: 0 to 9, function keys and operation command keys, 4: counter, 5: operation circuit, 6: speed setting circuit, 7: tape speed control circuit, 8:
Capstan motor.

Claims (1)

[Claims] 1. A rotary encoder that generates a pulse signal depending on a rotation direction and a rotation angle of a rotating body, and a counter that counts pulses from the rotary encoder.
A device having keys 0 to 9 for making a numeral, a function key for setting a tape speed, and an operation command key for performing an operation, and a tape speed value based on the data obtained by operating the keys. A tape speed setting method characterized by comprising an arithmetic circuit for arithmetically processing and a speed setting circuit capable of arbitrarily selecting a plurality of speed setting inputs.