JPH01265221A - Scanner for light beam scanning - Google Patents

Abstract

PURPOSE:To obtain the small-sized, inexpensive, and long-life scanner which has no slide part by forming a leaf spring fitted with a beam reflecting means and a coil which rotates the reflecting means in one body. CONSTITUTION:A mounting piece where a reflecting mirror 11 which obtains scanning light by reflecting a projection beam is stuck is fixed at one end of the leaf spring 9, whose other end is fixed to a yoke as a fixation member. Then a coil 7 is fitted to a hanger 10 above the leaf spring 9 and those mirror 11, spring 9, and coil 7 are formed in one body. When a current is supplied to the coil 7 through a lead wire 7, the coil 7 moves to rotate the hanger 10 around the leaf spring 9 as an axis and the mirror 11 is put in arcuate motion to generate the scanning light. Thus, the integral molding is performed, so the size is reduced, the cost is reduced, and there is not any slide part such as a galvanomirror, so that the life is prolonged.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 1] The present invention relates to a light beam scanning scanner for a distance measuring optical system.

■Background technology J Figure 15 shows a configuration diagram of a conventional optical beam scanning type i11 forward system, in which the light projection system 1 is a semiconductor laser or LED.
etc. as a light source, and the light is narrowly focused and projected through a projection lens. The scanning scanner 7--2', which rotates and reflects the light from the light projecting system 1, is composed of a polygon mirror or a rubano mirror, and scans the surface of the distance measurement object 3 in a straight line and reflects the reflected light. Light receiving lens 4 and PSD
(Semiconductor device detection element) 5 receives light.

The distance measurement principle is optical triangulation 11' as shown in Figure 16.
i, and when the object is at A, the culmination point is a on PSD5
, when B is bSC, it becomes C, and PSD5
By detecting a, b, and e, the distance r to the object can be determined. Since this beam is scanning in the direction perpendicular to the plane of the paper, two-dimensional displacement can be measured from the swing angle θ of the mirror of the scanning scanner 2' and the output of the PSD 5.

The PSD (semiconductor device detection element) 5 is a light receiving element that detects the actual position, and its structure is shown in FIG. 17 and its equivalent circuit is shown in FIG. 18, respectively. As shown in the figure, PSD5 is pin
Output electrodes 5□5 on both ends belonging to the structure of 7 otodiodes
It is a photovoltaic element with □. Now, when a light spot is irradiated on table n, the high resistance pM is the luminance gravity center position of the light,
Divided in inverse proportion to the distance to both N poles, the likelihood point Wt
When the length of PSD5 is L, a is expressed by the following equation.

Therefore, from formulas ■ and ■, becomes.

A polygon mirror or a mirror is usually used as a device for spotting light. The former is 6 to 12
Since the polygon mirror is rotated by a motor, it can be used at high speed and with a large scan angle, so it is widely used. However, manufacturing polygon mirrors with high precision is extremely expensive. Furthermore, since the polygon mirror is rotated by a motor, there is a limit to the life of the motor's bearings. In addition, since the shape is large, it is difficult to use it in a forward light sensor scanner for factory automation. The latter has a pair of permanent magnet stator and rotor, and a pair of control coils that control the rotation angle of the rotor.It is lower in cost than the polygon mirror, but like the former, it is difficult to control the sliding of bearings, etc. In order to have a department,
The lifespan is comparable to that of a polygon mirror. In addition, although the shape is smaller than polygon mirrors, it is FA in terms of lifespan and price.
It was unreasonable to use it in a destination optical sensor scanner.

Another big problem that is common to both is that ideally, the light beam scanned by a polygon mirror or a rubano mirror should move only in the scanning direction, but in reality, the bearing cannot move in the scanning direction due to the precision of the part. Wobbling perpendicular to the direction (Wob
Although this blur is small, ranging from several seconds to several tens of seconds in terms of angle, it causes a large distance measurement error in this distance measurement optical system. Specifically, it is as shown in FIG.

In the same figure, when the distance between the scanning scanner 2' and the reflective surface is 150-1, and the blur angle is 20 seconds, the distance measurement error is aR, the reflection angle is 10°, and θ#10°. Then, the distance measurement error can be calculated using the following formula.

I! 1Q = 150 It's a big hindrance.

[Objective of the Invention 1 The present invention is provided in view of the above-mentioned α,
The object of the present invention is to provide a light beam scanning scanner that is small, inexpensive, has little vibration, and has no sliding parts like a polygon mirror or an urban mirror and has a long life.

[Disclosure of the Invention 1 (Structure) The present invention comprises a movable member provided with a reflecting means for reflecting a projected beam to create a scanning light, one end of which is identified with the movable member, and the other end of which is supported by a rigid body. A leaf spring and a coil that bends the leaf spring in a direction substantially perpendicular to the plane of the leaf spring and rotates the movable member! A is provided so that the plate spring is deflected by the fill and the reflection means provided on the movable member is rotated to reflect the projected beam to create a scanning light. By integrally molding the movable part with the movable member, the movable part is lightweight, enabling high-speed operation, and is characterized by suppressing variations in characteristics.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In FIGS. 1 to 3, the rigid body is composed of two E-shaped yokes 6.6, and the iron core 6a of the yokes 6 is loosely fitted inside a coil 7 whose cross section is approximately square-shaped. . and,
The coil 7 is movable in the direction in which the iron core 6a protrudes.

Elastic plate springs 9 are provided at the end-to-edge portions on both sides of the yoke 6.
The lower part of the yoke 6 is supported, and the leaf spring 9 is identified by the yoke 6. A movable member If-10 is arranged parallel to the abutting surface of the yoke 6. Here, as shown in Fig. 1 and tpJ2, the upper part of the coil 7 and the upper part of the leaf spring 9 are integrally molded into the handle ff-10, and the plate is attached from the lower surface of both sides of the handle ff-10. The spring 9 is provided vertically. Further, a mounting piece 15 is integrally formed at one end of the handle 10 and is vertically disposed from the upper end and protrudes laterally, and after being integrally molded on the upper surface of this mounting piece 15, a reflecting means is formed. The reflecting mirror 11 is attached and the integrated handle constitutes one block A. As described above, the lower end of the leaf spring 9 is supported by the abutting portion of the yoke 6.

By the way, the reason why the coil 7, leaf spring 9, and hanger 10 are integrally molded is as follows. That is, in order to assemble the hanger block A, caulk the leaf spring to the hang and then glue it, and then glue the coil bobbin wound with a coil to the hang instead of making it bobbinless.
There are often variations in the characteristics of the scanner depending on the assembly precision.
Hump - Aluminum, a metal, is used to make the moving parts as light as possible.Furthermore, a coil bobbin is used and glued to the handle, which makes the moving parts heavy and hinders high-speed operation. This is because it becomes

For the above-mentioned reason, the Hager block 8 is integrally molded. As shown in FIGS. 1 and 2, the lead wire 7a of the fill 7 is formed in such a way that it extends directly from the center piece 10m of the handle 10.

A permanent magnet 12 is arranged within the opening 6b of the yoke 6. Here, since the iron core 6a is not identified when the fill 7 is excited, the coil 7 moves and the han ff
-10 rotates around the leaf spring 9, and the sixth
It moves in an arc as shown by the arrow in the figure. Therefore, the reflecting mirror 11 moves in the same manner as the mirror moves in an arc, and reflects the light beam to create scanning light. and,
In order to reduce wobble, the hand 7y-
The deflection portion 9a of the leaf spring 9 that deflects when the leaf spring 10 rotates is
The width dimension X is set to be longer than the length dimension y, and in this embodiment, it is about 1.5 times longer. The handle -10 is supported by the two leaf springs 9 designed in this manner. Incidentally, the reflecting mirror 11 corresponds to the scanning scanner 2' in FIG. 15, and the light beam is scanned by the circular motion of the hand 10. In addition, as shown in FIG. 4, the permanent magnet 12 is arranged so that its magnetic poles face each other.
Although the north poles are shown facing each other in the figure, they may be arranged so that the south poles are facing each other.

Next, the operating principle of the scanner will be explained. As shown in FIG. 4, a magnetic path is formed by the permanent magnet 12 and the yoke 6. Note that the broken line arrows in the figure indicate the flow of magnetic flux. At that time, a magnetic flux is flowing through the magnetic gap g as shown by the arrow in FIG. Therefore, when a current is passed through the coil 7 as indicated by the dashed arrow in Figure 5, a force is applied to the coil 7 from the front to the back of the page according to Lemming's left hand rule.Reverse the current in the coil 7. For example, since the direction of the magnetic flux is constant, a force acts on the coil 7 from the back of the page to the front.In this way, the direction of the current flowing through the fill 7 can be changed to a sine curve, a triangular wave, or a rectangular wave at a certain period. If the current waveform is changed to , a force proportional to the current waveform acts on the coil 7, and the magnitude of the force follows the law of f=I B i2°.

In the case of the coil 7 wound with n turns, n wires of length Q exist in a magnetic field with magnetic flux density B.

Therefore, since the current I flows through each electric wire, f=nlBQ. Furthermore, in the structure of this embodiment, the magnetic gear g formed by the permanent magnet 12a and the magnetic gap g formed by the permanent magnet 12b have the same magnetic flux density, so the force applied to the coil 7 is twice as much as the above equation as shown in the following equation. becomes.

f=2nIBQ where, n: 7 coils 1 (turn) I: Fill current (A) B: Magnetic flux density of gap g (Wb/m2) Q,: Effective length of conductor perpendicular to the magnetic field (plow) 1 : Force (N) applied to fill 7 (coil bobbin 8) When a force equal to or more than Since the coil 7 cannot move sideways, it is difficult to identify the support point p of the hanger 10 and the leaf spring 9.
It rotates as shown by the arrow in the figure around the rotation axis that exists in the darkness with αq. Therefore, the reflection mirror 11 identified in the handle 7y-10 moves in an arc in the same direction as the fill bobbin 8. This allows a scanner to be configured.

7 and 8 show the operating state of the scanner, and tI
Figure S7 shows the direction of the reflected light of the light beam when the scanner is in a stationary state, and Figure 8 shows the reflected light when the scanner is in a rotating state. Note that δ in the figure indicates a scan angle corresponding to the rotation angle when the scanner rotates. Here, S and α in FIG. 8 indicate the center of rotation. Further, the length of the permanent magnet 12 is designed to have a sufficient length so that the coil 7 does not come out of the magnetic field when the coil bobbin 8 moves. Furthermore, a handle 10, a reflection mirror 11
It is advantageous to reduce the weight of the hanger block, which is the movable part of the coils 7 and 9, as much as possible in order to improve the responsiveness of the scanner. For this reason, in this embodiment, a bobbinless fill 7 is used. Also,
In this embodiment, the longer the distance between the two leaf springs 9, the more the vibration (W).

Needless to say, the result is that the value (bble) becomes smaller.

By the way, Figure 9 shows the above scanner with a head case,
In addition to the scanner, the head case 13 includes a light receiving lens 4, a PSD 5, and a PS
An electronic circuit unit 14 and the like that perform arithmetic processing on the D5 output are arranged. Then, the scanner uses the reflecting mirror 11 as described above.
is placed in the i section of the handle 7y-10, so when installing it into the head case 13, the base M length can be reduced as much as possible to neatly fit the scanner inside the head case 13. It has an easy structure.

Further, the reflective surface of the reflective mirror 11 may be arranged on the rotational center axis of the handle 10. In other words, when the center of rotation is below the reflecting mirror 11, the reflecting mirror 11 makes a large circular arc movement, so the position at which the projected beam hits the reflecting mirror 11 changes.
A large reflection area is required. Therefore, the position of the surface of the reflecting mirror 11 is made to coincide with the rotation center axis of the handle 10, and as shown in FIG. Because of this, the incident light hits almost the same surface of the reflecting mirror 11, so the reflection area of the reflecting mirror 11 can be reduced. Therefore, the reflecting mirror 11 can be made smaller and the weight of the whole can be reduced. Note that when the reflecting mirror 11 rotates at an angle a, the reflected light is reflected at an angle 2a.

Figures 11 and 12 show the 10m center piece of Han 7y-io.
An embodiment is shown in which a drawer part 16 is formed on the upper surface of the filler 7 to draw out the lead @7a of the filler 7.
is formed by molding soft rubber or resin into a bellows shape at the same time as Han-10.

This lead-out portion 16 is intended to prevent wire breakage due to bending of the lead wire 7a.

13 and 14 show other embodiments of the drawer part 16, which can be pulled out from the handle 10 or drawn out from the handle 10.
The pull-out portion 16 is formed by folding back the pull-out direction and hardening it with a soft resin such as silicone. Therefore, by folding back the lead 1lli7a within the drawer portion 16, it is possible to prevent the lead M7a from breaking due to bending and pulling.

The pull-out portion 16 prevents the lead #i7a drawn out from the movable portion from being bent or broken due to tension.

[Advantageous Effects of the Invention 1] As described above, the present invention includes a movable member provided with a reflecting means for reflecting a projected beam to create a scanning light, and -11 is identified as the movable member, and fl! C) A coil that is a combination of a plate spring whose end is supported by a rigid body and a fill that rotates the movable member by bending the plate spring in a direction substantially perpendicular to the plane of the plate spring. By bending the leaf spring and rotating the reflecting means provided on the movable member, the projecting beam can be reflected to create scanning light. Therefore, the structure is simple, small, and inexpensive. It is possible to provide a scanner with small wobbling, and since there is no sliding part such as a polygon mirror or a louver/mirror as in the prior art, it has the effect of being able to have a long life. Furthermore, since the plate spring, fill, and movable member are integrally molded, no coil bobbin is used, and the number of movable parts of the scanner is 11! ! The coil, hanger plate spring, etc. are not assembled by caulking or gluing, but are integrally molded, reducing the possibility of variations during assembly. Therefore, this has the effect of suppressing variations in scanner characteristics.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a hanger block according to an embodiment of the present invention;
Figure 2 is a front view of the same as above, Figure PJ3 is a perspective view of the same scanner as above, Figure 4 is a plan view of the same as above, Figures 5 and 6 are explanatory diagrams of the same as above, Figures 7 and 8 are FIG. 9 is an explanatory diagram of the same Wt arrangement as above, FIG. 10 is an explanatory diagram of operation as above, FIG. 11 is a perspective view of the hanger block showing the drawer part as above, and FIG. 12 is a front view of the same as above. Fig. 13 is a perspective view of a handle 110 showing another embodiment of the above drawer section, Fig. 14 is a front view of the same as above, and Fig. PIrJ15 is a perspective view showing a conventional example of the beam scan type 81 hook system. Figure 16 is an explanatory diagram of the same operation as above, Figure tj417 is a diagram showing the structure of PSD, Figure 18 is an equivalent circuit diagram of the same as above, and Figure 19 is an operation explanation explaining distance measurement error due to shake in the conventional example. It is a diagram. 7 is a fill, 7& is a lead wire, 9 is a leaf spring, 10 is a handle, 111 is a reflection mirror, and 16 is a drawer. Agent Patent Attorney Ishi 1) 艮 77... Coil 11... -Reflection Miff- Figure 3 Figure 4 Figure 5 Figure 1゜Figure 6 Boat Zu-hi-b °1 3 whole- Fig. 9 Fig. 10 Fig. 11 Fig. 13 Fig. 15 Fig. 16 Fig. 17 Fig. 18 Fig. 19 Procedural amendment band (voluntary) June 11, 1985 1. Indication of the case 1988 patent M No. 94013 No. 2, Name of the invention: Light beam scanning scanner 3, Relationship with the person making the amendment Patent applicant address: 1048 Kadoma, Kadoma City, Osaka Prefecture Name (58
3) Matsushita Electric Works Co., Ltd. Representative Toshio Miyoshi 4, Agent postal code 530 Address 1-12-17-25 Umeda, Kita-ku, Osaka City Date of amendment order [1] No. 1 of the specification of the present application Page 15, line 19, [Since it is shaped, 1 should be corrected to "It is shaped." Agent Patent Attorney Ishi 1) Ai 7

Claims (3)

[Claims] (1) A movable member provided with a reflecting means for reflecting a projected beam to create a scanning light; a plate spring having one end identified with the movable member and the other end supported by a rigid body; and a flat surface of the plate spring. and a coil for rotating the movable member by bending a leaf spring in a direction substantially perpendicular to the light beam scanning scanner, wherein the leaf spring, the coil, and the movable member are integrally molded. (2) The light beam scanning scanner according to claim 1, wherein the lead wire of the coil is pulled out from the movable member, and a lead wire made of a soft material is formed in the lead wire to prevent wire breakage. (3) The lead wire of the coil is pulled out from the movable member, and a pull-out part made of a soft material for preventing disconnection is formed in the pull-out part, and the lead wire is folded back in the pull-out direction within the pull-out part. Scanner for light beam scanning.