JPH0634317B2 - Pickup position detector - Google Patents

Description

TECHNICAL FIELD The present invention relates to a device for detecting the position of a pickup of a player such as a laser disc or a compact disc.

SUMMARY OF THE INVENTION According to the present invention, the movement of a pickup, such as a laser disc or a compact disc, that reciprocates in a straight line is expanded and immovable via two sets of a transmission mechanism including a rack gear and a wheel gear. The brush in contact with the electric resistor is slid so that the position of the pickup can be accurately known from the change in the electric resistance value between one end of the electric resistor and the brush.

[Prior Art] As a device for electrically knowing the position of a linearly moving pickup, there has been a device shown in FIGS. 3 and 4 conventionally.

In the figure, 51 is a pickup that moves left and right, 5
Reference numeral 2 denotes a brush mounted on the lower surface of the pickup 51, and the brush 52 slides on a stationary electric resistor 53 (hereinafter simply referred to as a resistor) together with the pickup 51.

In this device, the position of the pickup 51 can be known from the change in the resistance value between the brush 52 and one end (for example, the left end) of the resistor 53.

[Problems to be Solved by the Invention] However, in the above-described device, the position of the pick-up 51 detected by the state of the sliding surface of the brush 52 or the resistor 53 or the nonuniform resistance value of each part of the resistor 53, Some errors will occur.

[Means for Solving the Problems] The present invention solves the above-mentioned problems by expanding the movement of the pickup through a reduction mechanism including a rack gear and a wheel gear and sliding the brush. It is a thing.

[Operation] According to the present invention, the speed reducing mechanism including the rack gear and the wheel gear allows the brush, which is moved by being greatly expanded as compared with the movement of the pickup, to slide on the resistor and accurately detect the position of the pickup.

[Embodiment of the Invention] FIGS. 1 and 2 show an embodiment of the present invention.
And 2 are pickups and brushes similar to 51 and 52, respectively, and 3 is a resistor corresponding to 53.

A first rack gear 4 facing the left-right direction is fixedly provided on the lower surface of the pickup 1, and a tooth wheel provided on the lower surface of the first rack gear 4 is meshed with a first wheel gear 5 having a small diameter.

On the side surface of the first wheel gear 5, a second large-diameter coaxial wheel is provided.
The wheel gear 6 is fixed, and both wheel gears 5 and 6 are
It is pivotally mounted on the immovable member 7.

The second wheel gear 6 meshes with the tooth row on the upper surface of the second rack gear 8 that is parallel to the first rack gear 4.

The brush 2 is mounted on the lower surface of the second rack gear 8 and slides on the resistor 3. .

In the above-described device, when the first rack gear 4 on which the pickup 1 is mounted moves, for example, in the direction of the arrow, the first and second wheel gears 5 and 6 rotate, and the second rack gear 8 carries the brush 2. Move in the direction of the arrow.

When the moving amount of the first rack gear 4 is L, the moving amount of the second rack gear 8 is 1, the number of teeth of the first wheel gear 5 is N, and the number of teeth of the second wheel gear 6 is n, between these, As is well known, the following relationships exist.

That is, by increasing the tooth number ratio between the second wheel gear 6 and the first wheel gear 5, the movement amount of the brush 2 can be made significantly larger than the movement amount of the pickup 1.

At this time, naturally, the length of the resistor 3 also needs to be increased corresponding to the movement amount of the brush 2.

[Advantages of the Invention] As described above, according to the present invention, the amount of movement of the pickup is significantly expanded by the reduction mechanism including the rack gear and the wheel gear, and the substantial length of the resistance is also increased. Even if the play existing in the moving device, the state of the sliding surface of the brush or the resistor, or the uniformity of the resistance value of each part of the resistor is the same as the conventional one, the adverse effect is reduced and the detected pickup Position accuracy is significantly improved.

The deceleration mechanism is not limited to that of the above-described embodiment, and various types of resistors can be used as the resistor, and it is also applicable to a detection method using an optical sensor and magnetism. it can.

[Brief description of drawings]

1 is a side view showing an embodiment of the present invention, FIG. 2 is a front view thereof, FIG. 3 is a side view of a conventional device, and FIG. 4 is a front view thereof. 1 ... Pickup, 2 ... Brush, 3 ... Resistance, 4 ... First rack gear, 5 ... First wheel gear, 6 ... Second wheel gear, 8 ... Second rack gear.

Claims (1)

[Claims] 1. A device for changing the resistance value of a linear resistor according to the amount of movement of the pickup and detecting the position of the pickup from the resistance value, wherein a reduction mechanism is provided between the pickup and the linear resistor. , A pickup is configured to be expanded and transmitted to a linear resistor, and the reduction mechanism meshes with a first rack gear on which the pickup is fixedly mounted, and a tooth row provided on the first rack gear. A first wheel gear, a second wheel gear that is coaxial with the first wheel gear and has a larger diameter than this, and a second rack gear that has a tooth row that meshes with the second wheel gear. A pickup position detecting device characterized in that the resistance value of a linear resistor is changed.