JPH0485749A - Control system for cassette loading motor - Google Patents

Abstract

PURPOSE:To partially slow down the cassette loading speed by varying the input voltage value of a drive circuit which is generated at each articulation point of a cassette loading action. CONSTITUTION:A photosensor 3 provided at a articulation point of a cassette loading mechanism part detects a fact that an interrupter 4 synchronized with a cassette holder mobile pat gets close to the articulation point and transmits a signal to an interface circuit 5. Based on this signal, a variable speed timing signal generating circuit 6 produces a motor slow-down timing signal as shown in a diagram. The pulse generated by a PWM speed changing circuit 7 is added within the slow-down timing for production of a control input signal of a drive circuit. As a result, the effective voltage level of a motor drive drops and the speed of the cassette holder is reduced by 100-50% of the steady speed at the articulation point.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to the field of video equipment, and more particularly to a control device for a cassette loading motor.

(Prior Art) Conventionally, this type of motor control device controls a loading DC motor 1 via a drive circuit 2 as shown in FIGS. 3 and 4.
Since the motor is driven by applying a constant voltage to It was running at speed.

(Problems to be Solved by the Invention) In the conventional motor control device described above, since the voltage applied to drive the motor is constant, at the following fluctuation points during the cassette loading operation, the cassette holder support and the inner circumference of the guide groove The disadvantage is that the parts collide, leading to deterioration of the parts and generation of abnormal noise.

Fluctuation point, initial point of loading, point where the cassette holder moves from horizontal movement to descent, point just before loading is completed, point just before unloading is completed, and other fluctuation points The object of the present invention is to To provide a control device for a cassette loading motor that does not cause deterioration of parts or generate abnormal noise.

(Means for Solving the Problems) The cassette loading motor control device of the present invention includes a sensor provided at each of the above-mentioned fluctuation points to detect when a cassette approaches that position, a drive circuit for the cassette loading motor, and a cassette loading motor control device as described above. It has an interface circuit that connects the sensor output to the drive circuit, a generator circuit that creates the timing to reduce the loading speed in response to the sensor output, and a speed change circuit that changes the drive circuit input and decelerates it in accordance with the timing. ing.

(Example) Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention. Second
The figure is a timing chart for each part of FIG. 1.

In FIG. 1, a photosensor 3 provided at a fluctuation point of the cassette loading mechanism section detects that an interrupter 4 synchronized with the cassette holder movable section approaches the fluctuation point, and sends a signal to an interface circuit 5. Based on this signal, a motor deceleration timing signal is generated in the shift timing signal generating circuit 6 as shown in FIG. A pulse generated by the PWM speed change circuit 7 is placed within this deceleration timing and is used as a control input signal for the drive circuit. As a result, the effective voltage of the motor drive decreases and the holder decelerates to 100-50% of the steady speed at the above fluctuation point.

As the shift timing signal generation circuit used above, a commonly known pulse generator circuit was used.

(Effects of the Invention) As explained above, the present invention allows the cassette loading speed to be partially reduced by varying the drive circuit input terminal value generated by the above circuit configuration at each variation point of the cassette loading. .

As a result, the cassette loading operation became softer, and the following advantages were obtained.

- Prevents erroneous operation due to rapid retraction and over-holding when inserting a cassette.

- Reduced the impact caused by collision of moving parts at fluctuation points to 1/36 or less.

- Unpleasant operating noise has been reduced by 7 dB (A) through the above collision reduction.

・Since the overrun amount due to software operation was reduced to 1750 or less, separate parts to reduce the overrun amount are no longer required.

The advantages described above have the effect of improving the reliability of the cassette loading mechanism.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a control device for a cassette loading motor according to the present invention. FIG. 2 is a diagram showing changes in signals in each circuit of FIG. 1. The third country is a functional diagram of a conventional cassette loading motor control device. 4 is a diagram showing changes in signals in the circuits of FIGS. 1 to 3; FIG.

Claims (1)

[Claims] A recording and reproducing apparatus using a cassette includes a detection means for detecting when the cassette approaches a specific location during a stroke of movement of the cassette, and a steady state of the moving speed of the cassette at the specific location based on the output of the detection means. A control device for a cassette loading motor, comprising: a control circuit for reducing the speed of the motor.