JPS58184926A - Optical scanner - Google Patents

Abstract

PURPOSE:To generate many scanning lines more than the number of optical elements arranged on a disc, by changing the position of an incident laser light in accordance with the rotation of the disc. CONSTITUTION:In case of the incident laser light, scanning lines indicated by solid lines are formed by one rotation of a disc; and if the position of the inciding light is changed as shown by broken lines after one rotation of the disc and the disc is rotated once more, scanning lines indicated by broken lines are formed so as to be interpolated between scanning lines indicated by solid lines. The laser light emitted by a laser light source 4 passes through a galvanomirror deflector 5 and is incident to an optical element 1 such as a hologram, a lens, or the like on the disc 2. The incidence position of the laser light incident onto the optical element 1 is displaced synchronously with the rotation of the disc by the operation of the deflector 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical scanning device, particularly to an optical scanning device for laser recording and display devices.

FIG. 1 shows an optical system for generating multiple scanning layers using a conventional disk-type optical scanner using optical elements such as holograms or lenses. In the figure, when a laser beam 3 is incident on a disk 2 and the disk 2 is rotated in the direction of the arrow, one scanning line 4 is formed corresponding to one hologram or one lens on the disk. Therefore, the number of scanning lines generated in the conventional optical scanner is limited by the number of optical elements such as holograms or lenses on the disk.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical scanner that generates more scanning edges than the number of optical elements (lenses or holograms) arranged on a disk.

In order to achieve the above object, the optical scanner of the present invention is characterized in that the position of the incident laser beam is changed in accordance with the rotation of the disk. The present invention will be explained below with reference to the drawings. FIG. 2 is a diagram showing the principle of the present invention. In the case of the incident laser beam shown by the solid line in the figure, the scanning line shown by the solid line is formed by one rotation of the disk, but after one rotation of the disk, Change the position of the incident laser f as shown by the chain line,
When the disk '1 is further rotated once, a dashed scanning line can be formed to exactly interpolate the scanning line indicated by the solid line.

FIG. 3 shows an embodiment of the present invention.

The disk 2 is driven by a motor 8 and rotates n times.

9 indicates a motor drive circuit. An encoder signal for detecting the rotation angle of the motor is outputted from the motor 8 and inputted to the optical deflector drive circuit 7 . The original deflector drive circuit 7 generates an optical deflector drive signal synchronized with the encoder signal from the motor,
The optical deflector 5 is driven.

The laser light emitted by the laser light source 4 passes through a galvanometer and a deflector 5, and is incident on an optical element 1 such as a hologram or a lens on the disk 2.

By the operation of the galvanometer mirror deflector 5, the incident position of the laser beam incident on the optical element 1 is displaced in synchronization with the rotation of the disk. 6 indicates a lens.

Figure 4 shows the change over time in the deflection angle θ of the galvano mirror deflector. Figure 5 shows the scanning line obtained when the galvano mirror deflector is operated as shown in Figure 5. - Assuming that the deflector 5 is operating sufficiently slowly, one revolution of the disk at the times shown in FIG. A line is formed.

Similarly, when proceeding from the time lapse shown in Fig. 4 to N, γL
1 Scanning lines shown in FIGS. 2 to 5 are formed. Therefore, it is possible to realize N times as many scanning lines as the number of optical elements on the disk.

Although FIG. 3 shows the case where a galvanometer mirror is used as the deflector, the same operation may be performed using a piezo element or a mechanical coupling mechanism.

As described above, according to the present invention, a large number of scanning lines with a fine scanning line pitch can be generated.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional optical scanner, FIG. 2 is a diagram showing the operation of the optical scanner of the present invention, FIG. 3 is a diagram showing an embodiment of the present invention, and FIG. 4 is a diagram showing the apparatus of the present invention. An explanatory diagram of the scanning line obtained by
FIG. 5 is a diagram showing the operation of the optical scanner in the apparatus of the present invention. Agent Patent Attorney Rishin Usuda 'vi'''I Figure 2 - vJ 4 Figure

Claims (1)

[Claims] 1. In an optical scanner that performs optical scanning by rotating a hologram or lens placed on a disk, the position or angle of the incident laser beam is changed in synchronization with the rotation of the disk, and the number of scanning lines that can be obtained is essentially n. An optical scanning device characterized in that: