JPH0882757A - Biaxial luminous flux driving device - Google Patents

Abstract

PURPOSE: To provide a biaxial luminous flux driving device simple and easy in assembling, small in size and light in weight. CONSTITUTION: This device is provided with a movable part consisting of a yoke 3 consisting of ferromagnetic body fixed to a reflection mirror 1 reflecting a required luminous flux and a magnet 2 having a doughnut shape and magnetized into four poles, a pin 4 pivotally supporting the rear surface center of the reflection mirror 1 through a leaf spring turnable around two axes, four pieces or integral multiple pieces of four of coils 5, 9 opposing to the magnet 2 and arranged in a plane shape at a prescribed interval and a fixed yoke 6 arranged on the rear side of the coils 5, 9 and attached to a casing 15 and consisting of the ferromagnetic body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-axis light flux driving device suitably used in, for example, a laser beam printer, an object reading device, a laser marking, a laser trimming, an image analysis and various measurement fields.

[0002]

2. Description of the Related Art FIG. 7 is a schematic view of a conventional two-axis driving device. In FIG. 7, 401 is a first reflecting mirror, which is provided on a main shaft 406. The main shaft 406 is rotationally driven by an actuator 403 that can drive only one shaft, and constitutes a first scan unit. Reference numeral 402 denotes a second reflecting mirror, which is provided on the main shaft 405. The main shaft 405 is rotationally driven by an actuator 404 that can drive only one shaft, and constitutes a second scan unit. Then, the first and second scan units are arranged so as to be orthogonal to each other within a predetermined plane.

Next, the operation will be described. The actuators 403 and 404 are used to form the first and second reflection mirrors 401 and 4
02 is rotated to drive the incident light beam 407 in the plane of the target 408 in the two directions of the X and Y axes.

[0004]

As described above, in the conventional two-axis light flux driving device, the first and second scan unit reflecting mirrors arranged so as to be orthogonal to each other within a predetermined plane are provided as two independent mirrors. Since the actuators are driven by individual actuators, there is a problem that a large space is required due to the arrangement of the actuators, and the entire system becomes large-scale. Further, there is a problem that it is difficult to adjust the position between the two actuators.

An object of the present invention is to obtain a two-axis light flux driving device which solves the above-mentioned problems of the conventional device.

[0006]

According to the present invention, there is provided a movable part comprising a yoke made of a ferromagnetic material fixed to a reflection mirror for reflecting a desired light beam and a donut-shaped magnet magnetized to have four poles, and the reflection. A pin that pivotally supports the center of the rear surface of the mirror through a leaf spring that is rotatable about two axes, and four pins that are opposed to the magnet and are arranged in a plane with a predetermined interval or an integral multiple of four. Since the coil and the fixed yoke made of a ferromagnetic material disposed on the back side of the coil and attached to the housing are provided, two axes can be simultaneously driven, and a compact and lightweight two-axis light flux driving device is provided. realizable. Further, since the drive source is a set of magnet systems, difficult position adjustment is completely unnecessary.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view showing a biaxial light flux driving device according to an embodiment of the present invention, and FIG. 2 is a top view thereof. 1 and 2
In the drawing, reference numeral 1 denotes a reflection mirror 1 for reflecting a light beam 16 from the outside, and a square reflection surface is reflection coated, and its side surface is mirror-finished so as to function as parallel plate glass, and functions as parallel plate glass. . A pin 4 is pivotally supported on a surface of the reflection mirror 1 opposite to the reflection surface via a ginpal spring 7 as a leaf spring rotatable about two axes, and the other end of the pin 4 is held by a housing 15. Has been done. A donut-shaped yoke 3 made of a ferromagnetic material such as electromagnetic soft iron is fixed to the gimbal spring 7, and a magnet 2 is fixed to the yoke 3.

Here, the gimbal spring 7 has a structure shown in FIG. The gimbal spring 7 is integrally formed using a material such as a spring material that is excellent in elastic deformation. Mouth-shaped fixed part 7
1, support portions 74a and 74b are provided on the inner sides facing each other, and a movable portion 72 is joined thereto, and the movable portion 72 is rotatable around the support portions 74a and 74b. Further, the square-shaped movable portion 72 is provided with second supporting portions 75a and 75b on the inner sides facing each other, and the second movable portion 73 is joined to the second supporting portions 75a and 75b. The movable portion 73 is rotatable. With this gimbal spring, the movable portion 73 flexibly rotates about the X axis and the Y axis with respect to the fixed portion 71.

As shown in FIG. 3, the magnet 2 has its surface magnetized into four poles. Here, the magnet 2, the yoke 3, and the reflection mirror 1 constitute a movable portion. The movable portion is rotatable about two axes by a pin 4 pivotally supported at the center of the back surface of the reflection mirror 1 through the gimbal spring 7.
5 is attached. FIG. 9 shows the structure of the coil portion.

Further, the housing 15 has four coils 5 and 9 wound in a substantially rectangular shape with a gap facing the magnet 2.
Or a multiple of 4 is arranged in a plane. A fixed yoke 6 made of a ferromagnetic material is disposed below the coils 5 and 9, and the magnetic fluxes produced by the magnet 2 and the yoke 3 that form the movable portion are collected and the magnetic flux transmitted through the coils 5 and 9. And a force for attracting the movable portion to the pin 4 side is generated, and the upward movement of the movable portion is restricted.

The coils 5 and 9 facing each other are connected as shown in FIG. The coils fixed in series with the magnetic lines of force generated by the magnet 2 are wound in opposite directions, and generate positive and negative forces, respectively. Along with this, the movable part is rotated.

10a and 10b are light sources such as semiconductor lasers, 11a and 11b are collimator lenses, 14a-1 and
14a-2, 14b-1, 14b-2 are reflection mirrors, 1
3a and 13b are light receiving sensors such as PDS,
a and 10b, the collimator lens 11a, and the reflection mirrors 14a-1 and 14a-2 to form the incident optical system.
4b-1 and 14b-2 and the light receiving sensors 13a and 13b constitute an output optical system. A pair of the input optical system and the output optical system are arranged on orthogonal axes, and are arranged in two axial directions of the movable portion. It is used to measure the rotation angle. As shown in FIG. 4, the light source 10a or 10b and the collimator lens 1 are
A slit plate 30 may be arranged between 1a or 11b.

Next, the operation of the above embodiment will be described with reference to the control block diagram shown in FIG. The light from the light source 10a is made into a substantially parallel light flux by the collimator lens 11a, passes through the reflection mirrors 14a-1 and 14a-2 twice, and enters the side surface of the reflection mirror 1 of the movable portion. The light flux passing through the inside of the reflection mirror 1 and emitted from the side surface on the reflection side is reflected by the reflection mirror 1.
4b-1 and 14b-2 are passed twice to receive the light receiving sensor 13a.
To reach. Also, the light from the light source 10b is
The light sensor 13b is reached via a-1, 14a-2, 1, 14b-1, and 14b-2.

Since FIG. 1 shows the neutral state, the electric outputs of the light receiving sensors 13a and 13b represent the zero point output in the neutral state.

Target position information (X, Y) from a computer (not shown) or the like is recalculated by the controller 71 into the deflection angle of the movable portion, and the drive currents of the pair of coils 5 and 9 are determined. This is converted into a current by the drivers 73 and 72, and the current is passed through the coils 5 and 9 to move the movable part. The moving angle of the movable part is determined by the light receiving sensors 13a, 13a.
The output voltage from b is fed back to the controller 71, the amount of deviation from the target angle is calculated again, and the current is supplied to the coils 5 and 9.

FIG. 6 shows a state in which a predetermined current is passed through the coil 5 and the movable portion is tilted in one axis direction. In this case, since the reflecting mirror 1 of the movable part plays the role of a parallel plate glass, the position of the light beam from the light source 10a is shifted downward on the light receiving sensor 13a, so that the light receiving sensor output at this time and the zero point output are By comparing
The tilt angle of the movable part can be calculated. Therefore, by arranging two angle measuring systems as shown in FIG. 2 on orthogonal axes, it is possible to calculate the rotation angle of the movable portion around the two axes.

[0017]

As described above, according to the present invention, it is possible to drive in two axial directions at the same time by the drive source composed of the coils arranged on the orthogonal axes and a set of magnet systems that act the magnetic flux on the coils. With this configuration, it has become possible to achieve a marked reduction in size and weight. Further, in the conventional device using the actuator as the drive source, the position adjustment between the actuators was extremely troublesome, but since the present invention does not use the actuator, the position adjustment is unnecessary, and the assembly is easy and easy. There is an effect that a two-axis luminous flux driving device can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment according to the present invention.

2 is a front view of FIG.

FIG. 3 is a perspective view of a magnet

FIG. 4 Diagram of optical system

FIG. 5 is a control block diagram for explaining the operation of the embodiment.

FIG. 6 is a state diagram in which the movable part is tilted.

FIG. 7 is a perspective view showing a conventional example.

FIG. 8 is a schematic view of a gimbal spring.

FIG. 9 is a schematic view of a coil portion.

FIG. 10 is an explanatory diagram of coil connection.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 reflection mirror 2 magnet 3 yoke 4 pin 5 coil 6 fixed yoke 7 gimbal spring (leaf spring) 10 light source 13a, 13b light receiving sensor 14a-1, 14a-2, 14b-1, 14b-2 reflection mirror 15 case

Claims (2)

[Claims] 1. A movable part composed of a yoke made of a ferromagnetic material fixed to a reflection mirror for reflecting a desired light beam and a donut-shaped magnet magnetized with four poles, and the center of the back surface of the reflection mirror is biaxial. A pin that is pivotally supported via a leaf spring that can be rotated around, four coils that are opposed to the magnet and are arranged in a plane with a predetermined interval, or an integral multiple of four coils, and the back side of the coil. And a fixed yoke made of a ferromagnetic material, which is attached to the casing and is attached to the casing. 2. An incident optical system that shapes light from a light source disposed in the casing into a substantially parallel light flux and enters the side surface of the reflection mirror, and the parallel light flux that has passed through the side surface of the reflection mirror. An output optical system for projecting on a light receiving sensor, a pair of the input optical system and the output optical system are arranged on orthogonal axes, and based on the output signal of the light receiving sensor corresponding to each output optical system, The two-axis light flux driving device according to claim 1, wherein an inclination angle of the reflection mirror is measured.