JPH0451110A - Position detection system for scanning rotary mirror - Google Patents

Abstract

PURPOSE:To enable accurate position detection by providing a 1st light receiving element which receives light only from one reflecting surface vertically above a light emitting element and a 2nd light receiving element which receives light from all reflecting mirrors vertically below the light emitting element. CONSTITUTION:The rotary mirror 10 which has plural slanting surfaces at plural tilt angles is used to make an optical scan and the light emitted by the light emitting element 13 is reflected by the rotary mirror 10 and detected by the light receiving elements to detect the rotational position of the rotary mirror 10. At this time, the 1st light receiving element 11 which receives the light from one reflecting surface is arranged vertically above the light emitting element 13 and the 2nd light receiving element 12 which receives the light from all the reflecting surfaces is provided vertically below the light emitting element 13. Therefore, scanning start time can be set with the light signal from the one reflecting surface. Consequently, the positions of the reflecting surfaces can accurately be detected without making any position adjustment, the respective surfaces can be detected, and the high-accuracy rotary mirror scanning using a small number of components becomes possible.

Description

[Detailed Description of the Invention] [Summary] Regarding position detection in a rotating mirror that receives images by performing optical scanning, an object of the present invention is to provide a rotating mirror method with highly accurate position detection, and to provide a rotating mirror system with multiple tilt angles. In the apparatus, which performs optical scanning using a rotating mirror made of a reflective surface, and detects the reflected light by applying light emitted from a light emitting element to the rotating mirror to detect the rotational position of the rotating mirror (10). , a first light receiving element vertically above the light emitting element that receives light from only one reflecting surface, and a second light receiving element vertically below the light emitting element receiving light from all the reflecting surfaces. A light receiving element is provided, and the configuration is such that the position of each reflective surface can be detected.

[Industrial application field]

The present invention relates to position detection in a rotating mirror that receives an image by performing optical scanning.In rotating mirror scanning, it is necessary to correctly detect the rotational position, and for rotating mirrors with tilt angles, it is necessary to detect the rotational position accurately with respect to the top and bottom of each reflective surface. Because it is angled, a structure is required to accurately detect each reflective surface number.

[Conventional technology]

FIG. 4 is a diagram showing an example of the structure of a conventional rotating mirror, with FIG. 4(a) being a schematic top view and FIG. 4(b) being a schematic side view. In the figure, 10 is a rotating mirror having a first surface 10a to an eighth surface 10h which are reflective surfaces, and 14 is a rotating shaft connected to a drive system. Further, 32 is a disk, 33 is a notch for detecting the first surface, and 34 is a notch for detecting each surface.

Further, 35 is a photocoupler for detecting the first surface, and 36 is a photocoupler for detecting each surface.

As shown in FIGS. 4(a) and 4(b), the conventional rotating mirror 10 has a first surface detection notch 33 and each surface detection notch 34 for position detection on the top surface of the rotating mirror 10. A disc 32 is mounted, which rotates together with the axis of rotation 14 and a rotating mirror lO coupled to the axis of rotation 14. For detection of each of the first surfaces 10a to 8th surfaces 10h, it is sufficient to detect only the first surface 10a, so a notch 33 for detecting the first surface is provided so that only the first surface 10a can be detected.
In addition, only the first surface detection notch 33 is cut deeply. In addition, as a detection structure, a photocoupler 3 for first surface detection is used.
5 and each surface detection photocoupler 36, and the first surface detection photocoupler 35 is installed deeply so that it cannot be detected at a position other than the first surface detection notch 33.

At the same time as the rotary mirror 10 rotates, the disk 32 also rotates, and when the first surface 10a comes to the position of the first surface detection photocoupler 35, a first surface detection output is sent from the first surface detection photocoupler 35. Ru. Moreover, each detection output of the first surface 10a including the first surface 10a to the eighth surface 10h is sent to the photocoupler 36 for detecting each surface. Note that the start position of each reflective surface can be detected by the output of the photocoupler 36 for detecting each surface.

(Problems to be Solved by the Invention) Therefore, there are problems in that positional deviation occurs due to the mounting accuracy of the disk and the accuracy of the detection notch provided on the disk, and that the number of parts increases due to the use of the disk. The object of the present invention is to provide a rotating mirror system with highly accurate position detection.

[Means for Solving the Problems] The present invention provides a rotating mirror 10 comprising a plurality of reflective surfaces with tilt angles.
The light emitting element 13 is used to perform optical scanning, and the light emitted from the light emitting element 13 is applied to the rotating mirror 10 and the reflected light is detected to detect the rotational position of the rotating mirror 10. A first light-receiving element 11 that receives light from only one reflective surface is located vertically above the light-emitting element 13, and a second light-receiving element that receives light from all reflective surfaces is located vertically below the light-emitting element 13. 12, and is configured so that the position of each reflective surface can be detected.

[For production]

In the present invention, as shown in FIG. 1, optical scanning is performed by using a rotating mirror 10 consisting of a plurality of reflective surfaces with inclined angles, and light emitted from a light emitting element 13 is reflected by the rotating mirror 10. When detecting the rotational position of the rotating mirror 10 by using a light receiving element, a first light receiving element 11 is provided vertically above the light emitting element 13 to receive reflected light from one reflecting surface, and the first light receiving element 11 is provided vertically above the light emitting element 13. A second light receiving element 12 is provided vertically below the light emitting element 13 to receive reflected light from all the reflecting surfaces.

Therefore, the scanning start time can be set using the optical signal from one reflecting surface, and highly accurate position detection becomes possible.

〔Example〕

FIG. 1 is a diagram showing the structure of the rotating mirror of the present invention, fa)
is a schematic top view, (bl is a schematic side view), and FIG. 2 is a diagram showing the operation of the rotating mirror of the present invention, (a) and (b)
l is a top view of the light receiving method, (C1 and (dl) are side views of the light receiving method. FIG. This is one example.

In the figure, 10 is a rotating mirror, 10a to 10h are first to eighth surfaces, 11 is a first phototransistor, 12 is a second phototransistor, 13 is a light emitting diode, 14 is a rotating shaft, 1
5 is a rotating mirror drive circuit. Further, 21 is a reflecting mirror, 22 is an infrared lens, 23 is a multi-element detector, 24 is a first axis multiplication circuit, 25 is an analog/digital conversion circuit (hereinafter referred to as an A/D conversion circuit), and 26 is a memory. be. Note 2
7 is a light emitting diode drive circuit, 28 is a second amplifier circuit, 2
9 is a third amplifier circuit, 30 is a microprocessor unit, and 31 is a television signal generation circuit. below,
The present invention will be explained in detail using FIGS. 1 to 3.

In FIG. 1, the light emitting diode 13 has a first surface 10a to
Light is emitted toward the eighth surface 10h, and this first surface 10a~
The reflected light from the eighth surface 10h is the first phototransistor 1
The first and second phototransistors 12 convert the signal into an electrical signal.

The first phototransistor 11, the second phototransistor 12, and the light emitting diode 13 are mounted at positions facing the mirror surface of the rotating mirror 10. First phototransistor 11
is attached above the light emitting diode 13 so as to receive light at an angle corresponding to the first surface 10a. Also, front page 1
Regarding light reception according to the second surface 10b to the eighth surface 10h other than 0a, a second phototransistor 12 is attached below the light emitting diode 13.

Note that the second phototransistor 12 must receive light corresponding to each of the second surface IOb to the eighth surface 10h.
The structure should have a long light-receiving surface in the vertical direction. In addition, the light emitting diode 13, the first phototransistor 11, and the second phototransistor 12 are provided close to each other in a position that does not interfere with the rotation of the rotating mirror 10, but in reality, the reflective surface opposite to the reflective surface used for image reception is preferable.

As shown in FIGS. 2(al) and (b), the rotating mirror 10 rotates, but the light emitted from the light emitting diode 13 is not received at the time of (a), and each of the first surface 10a to the eighth surface 10h is reflected toward the first phototransistor 11 or the second phototransistor 12 only in the case of FIG. The signal always indicates the position in front of the reflective surface.

In addition, Fig. 2 (C1 and (d) shows detection based on the inclination angle,
(C) shows when the first surface 10a is in front of the first surface 10
Light enters the first phototransistor 11 due to the tilt angle of a. (d) shows a state where the second surface 10b to the eighth surface 10h other than the first surface 10a are in front, and light enters the second phototransistor 2. In addition, each of the first side 10a to the eighth side 10h
Since the inclination angles of the two phototransistors are different, the light receiving point moves up and down, but since the second phototransistor 12 has a vertically long structure, light can be received.

In FIG. 3, as shown in FIGS. 1 and 2, the rotating mirror 10 has an inclination angle, and is driven by a rotating mirror drive circuit 15 to obtain an infrared image on each side each time it rotates. It is of structure. The incident light (infrared rays) is reflected by one of the first to eighth surfaces 10a to 10h of the rotating mirror 10, and the reflected light passes through the reflecting mirror 21 to the infrared lens 22.
to go into. The output light from the infrared lens 22 forms an image on a one-dimensional multi-element detector 23 and is converted into a video signal, which is then sent to the first amplifier circuit 2.
4, the signal is converted into a digital signal by the A/D conversion circuit 25, and is stored in the memory 26.

On the other hand, the light emitting diode 13 of the present invention emits light, and the reflected light is detected by the first phototransistor 11 and the second phototransistor 12, and is driven by the rotation drive mirror circuit 15 to detect the reflected light from the first surface 10a. The reflected signal from the first phototransistor 1 is input to the microprocessor unit 30 via the second amplifier circuit 28, or the second phototransistor for detecting reflected light on the second surface 10b to the eighth surface 10h The reflected signal from 12 is input to the microprocessor unit 30 via the third amplifier circuit 29. This microprocessor unit 30 calculates the position of the first surface 10a based on the reflective surface detection signal from the first surface 10a, determines the storage start time of the memory 26, outputs a video data writing control signal, and also outputs a video data writing control signal. 1st side 10a to 8th side 1
The start time of each memory is determined by the reflective surface detection signal of 0h, and the video data is written. The signal read from the memory 26 is converted into a television signal by the television signal generation circuit 31 and displayed on the television monitor.

As mentioned above, the image start time of each reflecting surface is determined by the rotating mirror 10.
is rotating at a constant speed, so the first surface 10a to the eighth surface 1
It can be calculated from the front detection signal of each surface of 0h that the image starting position to be actually used will be reached in a certain period of time.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the position of the reflecting surface can be detected with high precision without the need for position W adjustment, and each surface can be detected, and a high-precision rotating mirror with a small number of parts can be used. Can be scanned.

Therefore, it greatly contributes to improving the performance of the rotating mirror scanning imaging device.

14 is the rotation axis; shows.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the structure of the rotating mirror of the present invention, Fig. 2 is a diagram showing the operation of the rotating mirror of the invention, Fig. 3 is a diagram showing the configuration circuit of an embodiment of the invention, and Fig. 4 is a diagram showing the structure of the rotating mirror of the present invention. 1 is a diagram showing an example of the structure of a conventional rotating mirror. In the figure, 10 is a rotating mirror, 10a to 10h are first to eighth surfaces, 11 is a first light receiving element (phototransistor), 12 is a second light receiving element (phototransistor), and 13 is a light emitting element (
Light emitting diode), +b] 217 November's aro chapter = tteo 11 call 1 #ffi Figure 1 ℃ calculation 1 difference τ14 (Q) 32 yen / (b) Conventional f, turned 1 road! -σ Ba Jun Jun 4th m

Claims (1)

[Claims] Optical scanning is performed using a rotating mirror (10) consisting of a plurality of tilted reflecting surfaces, and light emitted from a light emitting element (13) is reflected by hitting the rotating mirror (10). detects the light
In the device for detecting the rotational position of the rotating mirror (10), a first light receiving element (11) that receives only light from one reflective surface is provided vertically above the light emitting element (13);
A second light-receiving element (12) is provided vertically below the light-emitting element (13) to receive light from all reflective surfaces, and the position of each reflective surface is detected. Scanning rotating mirror position detection method.