JPH01211325A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To easily position an optical head at a high speed and, at the same time, to make the space for an external light source unnecessary to as to miniaturize an optical information recorder and reproducing device by using a positioning scale instead of the external light source. CONSTITUTION:A beam splitter 5 which fetches part of the light emitted from a light source 3 for recording and reproduction, convergent lens 6 which converges the optical beam fetched by the beam splitter 5, positioning scale 2 provided with plural reflecting surfaces which converge the converged light 9 converged by the lens 6 in previously fixed directions and are arranged in the direction, in which an optical head 1 is moved, at previously fixed intervals near the converging point of the converged light 9, and photodetector 7 which receives the reflecting light of the converged light 9 reflected by the reflecting surfaces of the scale 2, are provided. Therefore, when the repeating times of a bright and dark pattern is counted, the moving distance of the optical head 1 can easily be known and the position of the head 1 can be controlled accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an information recording and reproducing device, and particularly to an optical disc device that optically writes and reads information on and from a disc-shaped information recording medium.

[Conventional technology]

Conventionally, an optical head of an optical disk device or the like uses a focus servo mechanism and a tracking servo mechanism to automatically focus and track a light beam on a predetermined track on the information recording surface of a rotating optical disk, etc., to write information on the optical disk. It is configured to read.

[Problem to be solved by the invention]

In order to fulfill the above-mentioned functions, the optical head of a conventional optical disc device is designed to be able to move in the radial direction of the optical disc or the like using a carriage.

When a light beam is used to access an arbitrary track at high speed, an optical head positioning scale or the like is used to recognize the approximate position of the optical head, and the address information recorded on the information recording medium is read using the light beam. However, a separate light source is required to read out the information on the positioning scale, and space must be secured to install it, which limits the ability to miniaturize the device. In addition, conventional optical position detecting means for optical heads generally use LEDs or the like as a light source, which causes large changes over time, making it difficult to obtain a stable position detecting signal over a long period of time. .

An object of the present invention is to provide an optical information recording/reproducing device that solves the above problems.

[Means to solve the problem]

In order to achieve the above object, an optical information recording and reproducing apparatus such as an optical disc device that records and reproduces information on an optical disc by condensing light emitted from a recording and reproducing light source of an optical head of the present invention onto the surface of a medium such as an optical disc. A beam splitter that takes out a part of the light emitted from the recording/reproducing light source, a focusing lens that focuses the light beam taken out by the beam splitter, and a focusing lens that converts the focused light focused by the focusing lens into a focused light. at least one positioning scale arranged such that a plurality of reflective surfaces that reflect in a predetermined direction are arranged at predetermined intervals near a focusing point in a direction in which the optical head moves; and a photodetector that receives the reflected light of the focused light reflected by the reflective surface.

〔Example〕

Next, one embodiment of the present invention will be described using the drawings.

FIG. 2 is an overall view of one embodiment of the present invention. In the figure, 1 is an optical head and 2 is a positioning scale.

Fig. 1 is a configuration diagram showing one embodiment of the present invention, Fig. 3, Fig. 4
FIG. 5 shows a diagram of the principle of the present invention.

In FIGS. 1 and 3, a light beam emitted from a recording/reproducing light source 3 is converted into parallel light 8 by a collimating lens 4, and this parallel light 8 is passed through a beam splitter 5, where a part of the parallel light 8 is reflected. let The beam splitter 5
A reflection mirror of about 10% is used, and most of the parallel light 8 passes through the beam splitter 5 and is used for recording and reproduction.

At step 22, the light reflected by the beam splitter 5 passes through the focusing lens 6 and is focused onto the positioning scale 2 fixed to the base plate of the optical disc device.
In this embodiment, the positioning scale 2 has a reflectance of nearly 100% for the light beam. The relationship between the first reflective surface 2-a and second reflective surface 2-b of the positioning scale 2 and the condensing point with respect to the moving direction of the optical head 1 will be explained using FIGS. 4 and 5. When the optical head 1 moves and the focal point of the focused light 9 is located at the reflecting surface 2-a as shown in FIG. 4, the focused light reflected by the reflecting surface 2-a is The light is irradiated onto the photodetector 7 and detected. Further, when the convergence point of the focused light 9 is at the position of the reflective surface 2-b as shown in FIG. direction and is not detected by the photodetector 7. Therefore, by moving the optical head 1,
The photodetector 7 repeatedly detects bright and dark patterns. Further, since the pitch of the reflective surfaces 2-a and 2-b is determined in advance, the moving distance of the optical head 1 can be easily determined by counting the number of repetitions of the bright and dark pattern.

In the optical head positioning mechanism of the present invention, the reflective surface 2-a of the positioning scale 2.

It goes without saying that the smaller the pitch of 2-b and the focused spot diameter of the focused light 9, the more accurate position control can be achieved.

〔Effect of the invention〕

As explained above, according to the optical information recording/reproducing apparatus of the present invention, the optical head can be easily positioned at high speed using the positioning scale without using an external light source, and furthermore, since no external light source is used, Space for an external light source is not required, and the device can be made smaller.

Furthermore, since a laser beam is used as the light source for position detection, there is little change over time, and there is an effect that a stable position detection signal can be obtained over a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is a perspective view of the entire system, and FIGS. 3, 4, and 5 are diagrams showing the principle of operation.

Claims (1)

[Claims] 1. In an optical information recording and reproducing apparatus such as an optical disc device that records and reproduces information on an optical disc by condensing light emitted from a recording and reproducing light source of an optical head onto a medium surface such as an optical disc, the light emitted from the recording and reproducing light source a beam splitter that takes out a part of the light beam taken out by the beam splitter; a focusing lens that focuses the light beam taken out by the beam splitter; and a focusing lens that focuses the light beam focused by the focusing lens at predetermined intervals near the focusing point of the focused light. , at least one positioning scale in which a plurality of reflective surfaces that reflect in a predetermined direction are arranged in a line in the direction in which the optical head moves, and the focused light reflected by the reflective surface of the positioning scale; 1. An optical information recording and reproducing device comprising: a photodetector that receives reflected light; and a photodetector that receives reflected light.