JPH01297617A - Light beam deflector - Google Patents

Abstract

PURPOSE:To improve high-speed responsiveness so that dealing with random scanning is enabled by directly driving a movable plate having a specular reflection surface. CONSTITUTION:A turning pivot part 11 as a pointed projection is projected from the center at the front surface of a mounting base 1 and plural pieces of sensors 2 and magnets 3 are disposed to the peripheral part of the front surface of the base 1. The sensors 2 and magnets 3 are both arrayed respectively at equal intervals in the circumferential direction around the turning pivot part 11 and are disposed in the positions where the sensors 2 and the magnets 3 align in a diametral direction. Namely, the movable plate 4 having the specular reflection surface 5 is linearly driven and, therefore, the mass of the moving part is only the movable plate 4 and the control of the direction of the plate 4 by the magnetic force of the plural magnets 3 is executable while the direction of the plate 4 is detected by the sensors 2. The high-speed responsiveness of the plate 4 is thereby enhanced and the dealing with the random scanning is enabled.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a light beam deflector used for changing the direction of a light beam in an optical scanner device or the like.

[Conventional technology]

A light beam deflector that changes the direction of a light beam by moving a movable plate provided with a specular reflection surface that reflects the light beam using magnetic force is disclosed in Japanese Patent Application Laid-Open No. 184434/1982. The optical beam deflector in 2011 moves the holder that pivots the movable plate, and since it is only intended for regular scanning by vibration rotation, it is difficult to know in which direction the optical beam is currently directed. had no means of detecting it.

[Problem to be solved by the invention]

For this reason, the above-mentioned conventional devices have large inertia and are inferior in high-speed response, and are also unable to perform random light beam scanning. The present invention has been devised in view of these points, and its object is to provide a light beam deflector that is excellent in high-speed response and is also capable of responding to random scanning.

[Means to solve the problem]

Therefore, the light beam deflector according to the present invention includes a movable plate made of a magnetic material having a specular reflection surface, a mounting base equipped with a rotation pivot supporting the center portion of the movable plate, and a movable plate. It consists of a sensor that detects the spacing at multiple locations, and a plurality of magnets that apply magnetic force to the movable plate to cause the movable plate to move around the pivot point. The plurality of magnets that act on the movable plate are characterized in that the magnetic force that is applied to the movable plate is variable. <Function> According to the present invention, since the movable plate with a specular reflection surface is directly driven, the mass of the movable part is only the movable plate, and the movable plate is driven by the magnetic force of a plurality of magnets. The orientation can be controlled by detecting the orientation of the movable plate using a sensor. <Example> The present invention will be explained below based on the illustrated example.
The figures and FIG. 2 show one embodiment, in which a pivot support 11 as a pointed projection is protruded from the center of the front surface of the mounting base 1, and the front circumference of the mounting base 1 is A plurality of sensors 2, four in the illustrated example, and four magnets 3 are arranged. Both the sensor 2 and the magnet 3 are
The sensors 2 and the magnets 53 are arranged at equal intervals in the circumferential direction with the sensor 2 as the center, and the sensors 2 and the magnets 53 are arranged in the radial direction.
placed where they match. The movable plate 4 has a specular reflection surface 5 at the center of the front surface for reflecting the light beam, and is a disc-shaped member made of a magnetic material.The movable plate 4 has a concave portion supported by the pivot support 11 at the center of the back surface. It has a pivoted part 40 as shown in FIG. Each of the sensors 2 described above measures the distance between its tip surface and the back surface of the movable plate 4 optically or by other methods, and the magnet 3 is formed of an electromagnet and is a movable magnet made of a magnetic material. The magnetic force exerted on the plate 4 is variable. The magnetic attraction force applied to the movable plate 4 from these magnets 3 maintains the state in which the center of the back surface of the movable plate 4 is received by the tip of the pivot support 11. In this light beam deflector, the direction of the movable plate 4, that is, the direction in which the light beam is reflected, is controlled as follows. That is, as shown in the tIS3 diagram, from each interval dl between each sensor 2 and the movable plate 4 detected by the sensors 2 arranged at equal intervals, (12, d3?d4, the orthogonal distance of the movable plate 4 Find the rotation angle (θ, θy), which is the two inclinations of the direction,
The magnetic attraction force F + - F that each magnet 3 gives to the movable plate 4 so that this value converges to the target angle θxi + θyi.
It controls F jlF-. In addition, θXlθy is θx=jan-' [(d+-dt)/L]θy
It can be calculated by performing the calculation = jan-'[(d2-cL)/L]. Figure 4 shows a state in which this light beam deflector is used to shine a light beam spot on the scanning surface, and the light spot coordinates (xi+yi) are the rotation angles (θxi, θy
Corresponds to i). As shown in FIG. 5, even if the position of the sensor 2 and the position of the magnet 3 are misaligned, by correcting the magnetic attraction force exerted by each magnet 3 according to the misalignment, the light can be emitted as in the case above. The direction of beam reflection can be controlled. Although four sensors 2 are used here, θX and θy can also be detected by a single sensor 2, respectively. In addition, in order to perform three-dimensional control of the movable plate 4, all four magnets 4 are constructed of electromagnets with variable magnetic force, but if two-dimensional control is sufficient, for example, as shown in FIG. Only the pair of magnets 3 lined up left and right may be electromagnets, and the magnets 3 lined up and down may be configured with permanent magnets. Another embodiment is shown in FIG. 6. The basic configuration is the same as the above embodiment, but here an air nozzle 12 is formed on the pivot support 11, and the air jetted from the air nozzle 12 is used to move the movable plate 4 is floating. In this case, since the movable plate 4 is supported in a non-contact manner, no frictional resistance or wear occurs, and high precision can be maintained over a long period of time. Further, as shown in FIG. 7, the mounting base 1 is covered with a transparent cover 15, and the air in the closed space 16 surrounded by the transparent cover 15 and the mounting base 1 is evacuated to create a vacuum state. If the movable plate 4 is arranged, air resistance will no longer act on the movement of the movable plate 4, which will further improve high speed, and the mirror reflection surface 5 will not become dirty, making maintenance easy by cleaning the transparent cover 15. You can get away with something. Furthermore, the movable IN, 4 is protected against external forces. Note that since the light beam passes through the transparent cover 15 twice, the light beam reaching the scanning surface becomes a little weaker due to absorption by the transparent cover 15, but the above advantages are enough to compensate for this. Optical processing can also be performed if the portion through which the light beam with the transparency power te-15 passes is configured with an optical member such as a light beam filter or a lens. Effect of the Invention 1 As described above, in the present invention, in order to directly drive the movable plate having a specular reflection surface, the mass of the movable part is only the movable plate, and the central part of the movable plate is pivoted. Therefore, the inertia of the movement of the movable plate can be reduced and high-speed response can be improved.In addition, the direction of the movable plate can be controlled by the magnetic force of multiple magnets, and the movable plate can be controlled by sensors. Since this can be done while detecting the orientation of the plate, it is possible to control the light beam with high precision, and it can also be used for random scanning.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of one embodiment of the present invention, Fig. 2 is a front view of the same, Fig. 3 is an explanatory view showing the action of the above, Fig. 4 is a perspective view of the same, and Fig. 5 is another 6 is a schematic sectional view of another embodiment; FIG. 7 is a schematic sectional view of another embodiment; 1 is a mounting base; 2 is a sensor; 3 is a magnet;
4 is a movable plate, and 5 is a specular reflection surface. Agent Patent Attorney Ishi 1) Ai 7 Figure 4 Figure 5 Figure 6 Figure 7 Procedural amendment (written on his own initiative) 1. Indication of the case 1988 Patent Application No. 128654 2. Name of the invention Light beam deflector 3. Relationship with the case of the person making the amendment Patent applicant Address 1048 Oaza Kadoma, Kadoma City, Osaka Name (583) Matsushita Electric Works Co., Ltd. Representative Toshio Miyoshi 4 Agent postal code 530 = 25 Date of amendment order Issue 6. Number of claims increased due to amendment None. 7. Target of amendment 1) "Optically delete J and insert [eddy current sensor]" on page 4, line 11 of the specification of the present application. 2) Delete "three-dimensional" in the second line of page 6 of the same page. 3) Delete four lines from line 4 to line 7 on the same page as above and insert the following sentence. ``Although it is strange that it is made up of electromagnets, for example, only one of the pair of magnets 3 lined up left and right in Figure 2 could be an electromagnet, and the other magnet 3 could be made of a permanent magnet.'' 4) Insert the following sentence next to "Dekiru." in the fourth line of the same page. ``Also, instead of air, non-contact support may be performed using magnetic repulsion.'' Agent Patent Attorney Ishi 1) Choshichi

Claims (1)

[Claims] (1) A sensor that detects the distance between a movable plate made of a magnetic material with a mirror-reflecting surface, a mounting base with a rotating pivot that pivots the center of the movable plate, and the movable plate at multiple locations. and a plurality of magnets that apply a magnetic force to the movable plate to cause the movable plate to move around the pivot point, and the plurality of magnets each apply magnetic force to different parts of the movable plate. A light beam deflector characterized by variable magnetic force acting on a movable plate.