JPH08254475A - Unbalance position detector for rotor - Google Patents

Abstract

PURPOSE: To eliminate provision of a phase mark for detecting an unbalanced part of a rotor. CONSTITUTION: A scanning optical system 11 including a polyhedral mirror 12 is equipped with an unbalance detecting means 13 to sense the unbalanced part of a rotor, a laser beam emitting means 14 to cast a laser beam onto the mirror 12, and a photo-sensor 16 to which a laser beam reflected by the mirror 12 is put incident. An amplifier 17, ring counter 18, and phase detecting means 19 are connected one by to the photo-sensor 16, and the unbalance detecting means 13 is connected to the phase sensing means 19. The ring counter 18 emits pulses each time the count of the photo-sensor 16 attains the number equal to the number of faces of the multi-surface mirror 12. From the time difference between the unbalance detecting means 13 and ring counter 18 the phase detecting means 19 senses the phase till the unbalanced part by reference to the output of the ring counter 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for dynamic balancing of a rotating body provided with a polyhedral mirror such as a scanning optical system, and in particular, the position of the unbalanced portion of the rotating rotating body is used as a phase. The present invention relates to an unbalanced position detection device for a rotating body for detection.

[0002]

2. Description of the Related Art As shown in the perspective view of FIG. 7, in a conventional general scanning optical system 1, a rotor 4 and a polyhedral mirror 5 are fixed to a rotary shaft 3 of a drive motor 2 and these rotary shafts 3 are fixed. The rotor 4 and the polyhedral mirror 5 are rotationally driven by the drive motor 2 as a rotating body. In order to detect such an unbalanced position of the rotating body of the scanning optical system 1 during rotation, an unbalanced amount of unbalanced portion of the rotary shaft 3 is detected by an unbalanced detecting means (not shown) while operating the drive motor 2. A phase detection means (not shown) detects the phase up to the unbalanced portion. Here, a phase mark 6 serving as a reference for detecting the phase is attached to the peripheral surface of the rotor 4, and the rotating phase mark 6 is read by the photo sensor 7.

[0003]

However, in the above-mentioned conventional example, since the phase mark 6 serving as a reference of the phase up to the unbalanced portion of the rotating body is required, it is troublesome to attach the phase mark 6 to the rotor 4. In addition, there is a problem that the phase mark 6 impairs the external appearance of the scanning optical system 1.

The object of the present invention is to solve the above-mentioned problems,
An object is to provide an unbalanced position detection device for a rotating body that does not require a phase mark on the rotating body.

[0005]

The unbalanced position detecting device for a rotating body according to the present invention for achieving the above object is a rotation for detecting the position of an unbalanced portion during rotation of a rotating body having a polyhedral mirror. An unbalanced position detection device for a body, wherein the unbalanced detection means is arranged to detect the unbalanced amount of the unbalanced portion, and the laser is arranged so that laser light is incident on the polyhedral mirror and emits substantially parallel laser light. A light emitting means, a photosensor which is arranged so that the laser light reflected by the polyhedral mirror is incident and outputs a pulse when a predetermined amount or more of laser light is incident, and the number of pulses output by the photosensor is counted. A ring counter that outputs a pulse each time the number of faces of the polyhedral mirror is counted, and a time difference between the output pulse of the ring counter and the output pulse of the unbalance detecting means. Calculated, characterized in that it consists of a phase detector for detecting a phase until the unbalanced portion relative to the output pulse of the ring counter.

[0006]

In the unbalanced position detecting device for a rotating body having the above-mentioned structure, the unbalance detecting means detects the unbalance amount of the unbalanced portion of the rotating rotating body. Laser light from the laser light emitting means is reflected by the mirror surface of the polyhedral mirror and input to the photo sensor, and the photo sensor outputs a pulse when a predetermined amount or more of laser light is incident. The ring counter counts the pulses output from the photosensor, and outputs a pulse to the phase detecting means each time the number of faces of the polyhedral mirror is counted. The phase detection means calculates the time difference between the output pulse of the ring counter and the output pulse of the unbalance detection means, and detects the phase up to the unbalanced portion based on the output pulse of the ring counter.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS. FIG. 1 is a configuration diagram of the present embodiment. For example, a scanning optical system 11 for detecting an unbalanced position of a rotating body is provided with a polyhedral mirror 12. Scanning optical system 11
An unbalance detecting means 13 for detecting the unbalance amount of the unbalanced portion of the rotating body is arranged on one side of the. On the other side of the scanning optical system 11, laser light emitting means 14 is arranged so that the laser light is incident on the mirror surface of the polyhedral mirror 12, and in the reflection direction of the laser light by the polyhedral mirror 12, a slit plate 15 and The photosensors 16 are sequentially arranged. The output of the photo sensor 16 is sequentially connected to the amplifier 17, the ring counter 18, and the phase detecting means 19, and the output of the phase detecting means 19 is connected to the television monitor 19a. The output of the above-mentioned unbalance detecting means 13 is connected to the phase detecting means 19.
Then, in the vicinity of the scanning optical system 11, which is used when balancing the unbalanced portion of the rotating body, the indexing means 20 for rotating the rotating body to determine the unbalanced position, and the unbalanced portion of the rotating body. Mass adjusting means 2 for adjusting the mass
1 is arranged. Also, these indexing means 20,
The mass adjusting means 21 is connected to the phase detecting means 19.

In the scanning optical system 11, as shown in FIG. 2, a rotor 33 constituting a part of the drive motor 31 and the above-mentioned polyhedral mirror 12 are fixed to a rotary shaft 32 of the drive motor 31. Sensors 13a and 13b of the unbalance detecting means 13 are arranged in the vicinity of the upper and lower sides of the rotating shaft 32 in a non-contact manner. The unbalance detection means 13 is a sensor 13
The unbalance amount of the unbalanced portion of the rotating body is calculated from the signals a and 13b, and is output to the phase detecting means 19 as the pulse A.

As shown in FIG. 3, the slit plate 15 is arranged so that the longitudinal direction of the slit 15a is perpendicular to the scanning direction X of the laser light, and the photo sensor 16 receives a predetermined amount of laser light or more. The pulse B is output to the pulse generator B, and the pulse B is electrically amplified by the amplifier 17. Then, as shown in FIG. 4, the ring counter 18 counts the number of pulses B output from the photosensor 16, and every time the number of faces of the rotating mirror 12 is counted, that is, the number of faces of the polyhedral mirror 12 of this embodiment is 6 The pulse C is output every time the pulse is counted.

The phase detecting means 19 takes in the pulse A of the unbalance detecting means 13 and the pulse C of the ring counter 18 and calculates the time difference between them, and at the same time calculates the pulse C of the ring counter 18 as the phase reference and the reference. The phase from the time difference to the unbalanced portion is detected.

The indexing means 20 is for controlling the rotation angle of the rotating body, and as shown in FIG. 5, a soft ring 43 is attached to the rotation shaft 42 of the stepping motor 41 whose rotation angle is freely controllable. It is movable in the direction Y as shown in FIG. 6 by a moving means (not shown), and the ring 43 is movable in and out of contact with the rotary shaft 32 or the rotor 33 of the scanning optical system 11.

The mass adjusting means 21 is, for example, an adhesive applicator for applying an ultraviolet curable resin, an instant adhesive or the like to the unbalanced portion of the rotating body, or a laser processing machine for removing the mass of the unbalanced portion with laser light. There is.

With this structure, when the drive motor 31 of the scanning optical system 11 is operated, the unbalance detecting means 13 detects the unbalanced portion of the rotating body through the sensors 13a and 13b, and the unbalanced portion is set as the pulse A. It is output to the phase detecting means 19. On the other hand, the laser light from the laser light emitting means 14 is reflected by the polyhedral mirror 12, passes through the slit 15 a of the slit plate 15, and enters the photo sensor 16.
The photo sensor 16 outputs a pulse B for each number of faces of the polyhedral mirror 12 from a predetermined amount or more of laser light that has passed through the slit 15 a, and an amplifier 17 amplifies the pulse B and inputs it to the ring counter 18. Ring counter 18 is pulse B
Pulse C is output to the phase detecting means 19 every time the number of faces of the polyhedral mirror 12 is counted. Phase detecting means 19
Takes in the pulse A of the unbalance detecting means and the pulse C of the ring counter 18, calculates the time difference between the pulse A and the pulse C, and detects the phase of the unbalanced portion from the time difference calculated using the pulse C as the phase reference.

Here, the drive motor 31 of the scanning optical system 11
Let the rotation speed of Mrs be Mrps, and let the number of faces of the polyhedral mirror 12 be N.
When the surface is used, the number of output pulses B of the photo sensor 16 is M × N / sec, and the output pulse C of the ring counter 18 is C.
Is M / sec. When the time difference between the measured pulse A and pulse C is H seconds, H / M × 360 ° is the phase angle from the reference to the unbalanced portion.

When balancing the unbalanced portion, the unbalance detecting means 13 detects the unbalanced amount of the unbalanced portion, and the phase detecting means 19 detects the phase of the unbalanced portion. The operation of the drive motor 31 is stopped. Next, the indexing means 20 is moved so that the ring 43 is moved to the rotary shaft 32 of the scanning optical system 11 or the rotor 3.
3, the motor 41 is operated to rotate the rotary shaft 42 by the angle detected by the phase detection means 19 from the reference detected by the ring counter 18. As a result, the position where the scanning optical system 11 is balanced is determined, and the mass adjusting means 21 applies an adhesive to increase the mass, or irradiates a laser beam to remove the mass.

As described above, in this embodiment, since the output pulse C of the ring counter 18 is used as the phase reference, it is possible to omit the need to attach a phase mark to the rotor 33 of the scanning optical system 11 as in the conventional case. The troublesome work of attaching the phase mark to the rotor 33 can be omitted, and the appearance of the scanning optical system 11 can be favorably maintained.

[0017]

As described above, in the unbalanced position detecting device for a rotating body according to the present invention, the time difference between the pulse output by the unbalance detecting means and the pulse output by the ring counter is calculated and output by the ring counter. Since the phase up to the unbalanced part is detected by the time difference calculated based on the pulse, it is possible to omit the work of attaching a phase mark to the rotating body,
The appearance of the scanning optical system can be maintained well.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a present embodiment.

FIG. 2 is a layout diagram of a scanning optical system and an imbalance detecting unit.

FIG. 3 is a perspective view of a slit plate and a photo sensor.

FIG. 4 is a waveform diagram of input / output pulses of a ring counter.

FIG. 5 is a layout view of a scanning optical system and indexing means.

FIG. 6 is an operation explanatory view.

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

[Explanation of symbols]

 11 Scanning Optical System 12 Polyhedral Mirror 13 Imbalance Detection Means 14 Laser Light Ejection Means 16 Photo Sensor 18 Ring Counter 19 Phase Detection Means

Claims (1)

[Claims] 1. An unbalanced position detecting device for a rotating body for detecting the position of an unbalanced portion of a rotating body provided with a polyhedral mirror, wherein the unbalanced portion is arranged to detect an unbalanced amount of the unbalanced portion. Detecting means, laser light emitting means arranged so that laser light is incident on the polyhedral mirror and emitting substantially parallel laser light, and laser light reflected by the polyhedral mirror are arranged so as to enter, and a predetermined amount or more is provided. A photosensor that outputs a pulse when laser light is incident, a ring counter that counts the number of pulses output by the photosensor, and outputs a pulse each time the number of faces of the polyhedral mirror is counted, and an output of the ring counter The time difference between the pulse and the output pulse of the unbalance detection means is calculated, and the phase up to the unbalanced portion is detected based on the output pulse of the ring counter. An unbalanced position detection device for a rotating body, comprising: a phase detection means.