JP2009098032A - Oscillator device, optical deflection device, and resonance frequency detection method - Google Patents

Abstract

There is provided an oscillator device capable of searching for a resonance frequency of an oscillator in a short time and appropriately setting a steady driving frequency in relation to the resonance frequency.
An oscillator device includes an oscillator having a resonance frequency, detection means 15 and 16 for detecting information related to an oscillation amount of the oscillator, a drive means 12 for driving the oscillator, and a control means 17. Have. The control means includes drive frequency changing means 108 for changing the drive frequency of the drive signal applied to the drive means. The control means causes the drive frequency changing means to sweep the drive frequency at a predetermined time change rate in the direction of the resonance frequency from the sweep start frequency that is separated from the resonance frequency. The drive frequency when the fluctuation amount based on the information output by the detection means in the sweep of the drive frequency reaches a peak is detected, and a frequency closer to the sweep start frequency than the drive frequency by a predetermined value is used as a preliminary or final frequency. To decide.
[Selection] Figure 1

Description

The present invention relates to a technical field of an oscillator device such as a resonance oscillator device having an oscillator such as a micro oscillator structure. In particular, the present invention relates to an oscillating device characterized by setting a drive frequency of a drive signal for driving the oscillating member, an optical deflection device using the oscillating device, and a resonance frequency for detecting a resonance frequency in the oscillating device. It relates to the detection method. The optical deflecting device using this oscillator device is an optical display such as an image display device such as a scanning display or a moving image drawing device, a laser beam printer (LBP), a digital copying machine, or an electrophotographic image forming device or drawing device. Applicable to equipment.

As a scan mechanism using a conventional resonance type oscillator device, there is a configuration as shown in FIG. 20 (see Patent Document 1). In FIG. 20, reference numeral 2210 denotes an optical deflector using a resonant oscillator, and the light beam from the light source 2200 is reflected and deflected by the optical deflector 2210. The oscillating body of the optical deflector 2210 is oscillated by generating an electromagnetic force using a coil (not shown) or the like. During the scan operation, the resonance oscillator is driven by a drive signal having the resonance frequency. In the optical deflector 2210, the resonance frequency varies depending on the characteristics and temperature characteristics of each device, and it is necessary to specify the resonance frequency when the apparatus is started. In the prior art, the optical deflector starts to be driven in advance with a drive signal having a frequency lower than the resonance frequency, and the resonance frequency is searched by gradually increasing the drive frequency.

For that purpose, we will do the following. In FIG. 20, reference numeral 2220 denotes a light receiving element, which is an element that converts an optical signal into an electric signal. The light receiving element 2220 is configured to receive the deflected light beam and detect the amount of deflection angle of the light beam, that is, the swing angle of the swinging body of the optical deflector. The speed of the change in the drive frequency is set to be sufficiently small so that the swing amount of the optical deflector reaches a steady state and the swing amount at the drive frequency can be measured correctly. When gradually increasing the drive frequency in this way, the oscillation angle of the oscillator of the optical deflector corresponding to each frequency is measured using the light receiving element 2220, and the drive frequency that maximizes the oscillation angle is specified as the resonance frequency. . The optical deflector is driven by using this resonance frequency as a steady driving frequency during the actual scanning operation.

In the other conventional technology, the resonance frequency is specified at the time of starting the resonance type oscillator as in the case of Patent Document 1 (see Patent Document 2). In this prior art, a light receiving element for a light beam is placed where a light beam having a certain deflection angle is received. The swing angle of the optical deflector is measured from the timing at which the light receiving element detects the light beam, that is, from the time interval at which the light beam crosses the light receiving element. Also in this conventional example, as in the case of the above-described Patent Document 1, the swing angle is measured when the drive frequency is gradually increased, and the drive frequency at which the swing angle is maximized is specified as the resonance frequency. The optical deflector is driven using this as a steady driving frequency in actual use.
JP 2005-241482 A U.S. Patent No. 7030708

However, this type of oscillating body has a high resonance sharpness (Q value), and when the drive frequency is changed, it takes time for the oscillating body itself to reach the steady state. Therefore, in the resonance frequency detection method according to the prior art, it is necessary to wait until the oscillation angle amount of the oscillator becomes stable every time the frequency is changed during the sweep of the frequency of the applied drive signal. Accordingly, it may take time to detect the accurate resonance frequency by sweeping the frequency within a certain range.

Thus, if it takes time to specify the resonance frequency of the oscillator, the startup time of the apparatus using the optical deflector having the oscillator is increased, and the performance is degraded. For example, when it is applied to a printer, there is a possibility that a print output will not be made unless a few minutes have passed after print data transmission.

In view of the above problems, the oscillator device of the present invention has the following characteristics. An oscillating body device includes at least one oscillating body having a resonance frequency and supported so as to be able to oscillate, detection means for detecting information relating to an oscillating amount of the oscillating body, driving means for driving the oscillating body, and control means. Have The control means includes drive frequency changing means for changing the drive frequency of the drive signal applied to the drive means. The control means causes the drive frequency changing means to sweep the drive frequency at a predetermined time change rate in a direction from the sweep start frequency away from the resonance frequency toward the resonance frequency. Then, the drive frequency when the fluctuation amount based on the information output from the detection means in the drive frequency sweep reaches a peak, and a frequency closer to the sweep start frequency than the drive frequency is set as the first resonance frequency, The resonant frequency is determined either preliminary or final.

In view of the above problems, the oscillator device of the present invention has the following characteristics. An oscillating body device includes at least one oscillating body having a resonance frequency and supported so as to be able to oscillate, detection means for detecting information relating to an oscillating amount of the oscillating body, driving means for driving the oscillating body, and control means. Have The control means includes drive frequency changing means for changing the drive frequency of the drive signal applied to the drive means. The control means causes the drive frequency changing means to sweep the drive frequency at a predetermined time change rate in a direction from the sweep start frequency away from the resonance frequency toward the resonance frequency. Then, the drive frequency when the change rate of the fluctuation amount based on the information output by the detection means in the sweep of the drive frequency becomes a positive predetermined value larger than 0 is detected, and this drive frequency is set as the first resonance frequency. The resonance frequency is determined preliminary or finally.

Moreover, in view of the said subject, the optical deflection | deviation apparatus of this invention has the following characteristics. The light deflector includes the oscillator device and a light beam generating means for generating a light beam. The oscillator has a mirror, and reflects and deflects the light beam generated by the light beam generator. The detection means includes light detection means arranged to detect the deflected light beam at a position of a predetermined deflection angle, and the control means controls the oscillation of the oscillator based on the interval of the light beam detection time of the light detection means. Detects the rate of change of the amount of movement or swing.

Moreover, in view of the said subject, the optical instrument of this invention has the following characteristics. An optical apparatus has the light deflection device and a light irradiation target, and the light deflection device deflects the light beam from the light beam generating means and makes at least a part of the light beam incident on the light irradiation target. Let

Moreover, in view of the said subject, the resonance frequency detection method of this invention has the following characteristics. A resonance frequency is determined in an oscillator device having at least one oscillator that has a resonance frequency and is supported so as to be capable of oscillation, detection means that detects information related to the oscillation amount of the oscillator, and drive means that drives the oscillator. It is a method of detection. The resonant frequency detection method includes the following steps.
A step of sweeping the drive frequency at a predetermined time change rate in a direction from the sweep start frequency separated from the resonance frequency toward the resonance frequency.
A step of detecting the drive frequency when the amount of oscillation based on the information output from the detection means reaches a peak in the drive frequency sweep;
A step of preliminarily or finally determining the resonance frequency with a frequency closer to the sweep start frequency than the driving frequency at the time of the peak as a first resonance frequency.

Moreover, in view of the said subject, the resonance frequency detection method of this invention has the following characteristics. A resonance frequency is determined in an oscillator device having at least one oscillator that has a resonance frequency and is supported so as to be capable of oscillation, detection means that detects information related to the oscillation amount of the oscillator, and drive means that drives the oscillator. It is a method of detection. The resonant frequency detection method includes the following steps.
A step of sweeping the drive frequency at a predetermined time change rate in a direction from the sweep start frequency separated from the resonance frequency toward the resonance frequency.
A step of detecting the drive frequency when the rate of change of the oscillation amount based on information output by the detection means in the drive frequency sweep becomes a positive predetermined value greater than zero.
A step of preliminarily or finally determining the resonance frequency with the drive frequency when the rate of change becomes a predetermined value as a first resonance frequency;

If the technique of the present invention is used, the sweep speed, which is the predetermined rate of time change, can be set faster than the conventional technique. Therefore, it is possible to find the resonance frequency of the oscillator in a short time and to appropriately set a steady drive frequency in actual use in relation to the detected resonance frequency. Thus, the startup time of the system using the oscillator device or the resonance frequency detection method of the present invention can be shortened.

Hereinafter, in order to clarify the embodiment of the present invention, a specific oscillator device and resonance frequency detection method will be described. First, before describing the embodiment, the basic configuration and operation of the oscillator device targeted by the present invention will be described with reference to FIG.

As shown in FIGS. 19A and 19B, the oscillator device includes at least a first oscillator 1901, a second oscillator 1902, a first torsion spring 1911, and a second torsion spring 1912. It has a system 1910 and a support portion 1921 that supports the vibration system. The first torsion spring connects the first oscillating body and the second oscillating body. The second torsion spring is connected to the second oscillating body so as to have a torsion axis common to the torsion axis of the first torsion spring. Here, the vibration system only needs to have at least two oscillating bodies and two torsion springs. As shown in FIG. 19, the oscillation system 1910 includes three or more oscillating bodies 1901, 1902, 1903 and three or more You may comprise the torsion spring 1911, 1912, 1913. Of course, as shown in FIG. 2 of the embodiment described later, an oscillating body device having one oscillating body supported so as to be able to oscillate may be used.

Further, it includes a drive unit 1920 that is a drive unit that applies a drive force to the vibration system, and a drive control unit 1950 that is a control unit that controls the drive unit 20. The drive unit 1920 drives the vibration system so that at least one of the one or more oscillating bodies has a vibration represented by an expression including the sum of one or more periodic functions. The drive control unit 1950 supplies the drive unit 1920 with a drive signal that causes such vibrations in the vibration system.

When the oscillator device is used as an optical deflection device, a reflection mirror is formed on at least one oscillator. As the reflection mirror, a light reflection film is formed on the surface of the oscillator. When the surface of the oscillator is sufficiently smooth, it can be used as a reflection mirror without forming a light reflection film. The light deflection apparatus further includes a light source 1931 that emits a light beam, and scans the light by irradiating the reflection mirror provided on the oscillator with the light beam 1932.

The operating principle of the oscillator device will be described. In general, the equation of free vibration of a vibration system including n oscillators and n torsion springs is given by the following expression 1.

ただし、I_ｋ：揺動体の慣性モ−メント、k_ｋ：ねじりバネのバネ定数、θ_ｋ：揺動体のねじれ角（揺動角）である（k＝1、・・・、n）。この系のM⁻¹Kの固有値をλ_ｋとすると（k＝1、・・・、n）、固有振動モードの角振動数（角周波数）ω_ｋは、ω_ｋ＝√（λ_ｋ）で与えられる。

Where I _{k is} the inertia moment of the oscillating body, k _{k is} the spring constant of the torsion spring, and θ _{k is} the torsion angle (oscillating angle) of the oscillating body (k = 1,..., N). If the eigenvalue of M ⁻¹ K of this system is λ _k (k = 1,..., N), the angular frequency (angular frequency) ω _k of the natural vibration mode is ω _k = √ (λ _k ). Given.

The oscillator device has a vibration system having n vibration modes including n oscillators and n torsion springs, and there are n-1 fundamental frequencies and integer multiples thereof in ω _k. With this configuration, various motions can be performed on the rocking body. In the present specification, the term “integer multiple” includes substantially integer multiple, and “substantially integer multiple” refers to a numerical range of about 0.98n to 1.02n times the fundamental frequency (n is an arbitrary integer). In particular, the oscillator device is composed of two oscillators and two torsion springs, and is configured so that there is a fundamental frequency and a frequency that is substantially an even multiple of the fundamental frequency in ω _k . It is possible to realize substantially constant angular velocity driving in which fluctuation of the angular velocity of the oscillator is suppressed.

Further, when n = 3, the vibration system having the rocking bodies 1901, 1902, and 1903 and the torsion springs 1911, 1912, and 1913 is set so that the frequency ratio of the three vibration modes is 1: 2: 3. Constitute. By simultaneously oscillating the vibration system in vibration modes 1 to 3 of this vibration system, it is possible to drive with a smaller fluctuation in angular velocity than in the case of n = 2. For example, there is a mode in which the vibration system is driven by setting the frequency ratio in each vibration mode to 1: 2: 3 and the amplitude ratio in each vibration mode to 24: -6: 1.

Thus, by increasing the number of vibration modes, the fluctuation of the angular velocity of the rocking body in a predetermined range can be further reduced. In addition, the oscillator device is composed of two oscillators and two torsion springs, and the oscillator is configured so that there is a fundamental frequency and approximately three times the frequency in ω _k. Can be driven.

As shown in FIGS. 19 (a) and 19 (b), a description will be given of the vibration of the vibration system of the embodiment including n oscillators and n torsion springs. This vibration system is configured to be capable of simultaneously generating a vibration motion that moves at a fundamental frequency and a vibration motion that moves at n-1 frequencies that are substantially an integral multiple of the vibration motion. Therefore, in one aspect of the embodiment, at least one of the plurality of oscillators is configured to have a vibration represented by an expression including a sum of one or more periodic functions. An expression including the sum of one or more periodic functions includes an expression including a constant term. For example, the case where the constant term is included is a case where a constant direct current bias is applied to the drive unit and the origin of the swing angle of the swing body (the position where the swing angle is 0) is shifted.

In another aspect of the embodiment, the deflection angle θ of the optical deflecting device (here, measured with reference to the position of the scanning center) is as follows. The amplitude and angular frequency of the first vibration motion are A ₁ and ω, respectively, and the amplitude and angular frequency of the second vibration motion are A ₂ and nω (n is an integer of 2 or more), and the first and second vibrations. Let the relative phase difference of motion be φ. Then, the motion of the oscillating body is a vibration represented by a mathematical formula including at least the term of A ₁ sinωt + A ₂ sin (nωt + φ). In particular, when n = 2, the mathematical expression includes at least the term of A ₁ sinωt + A ₂ sin (2ωt + φ), and it is possible to realize substantially constant angular velocity driving in which fluctuation of the angular velocity of the oscillating body in a predetermined range is suppressed. When n = 3, the mathematical expression includes at least the term A ₁ sinωt + A ₂ sin (3ωt + φ), and the oscillator can be driven in a substantially triangular wave. Also in this case, the formula including at least the term of A ₁ sinωt + A ₂ sin (nωt + φ) includes a formula including a constant term.

Further, in the embodiment, it can be performed as follows. That is, the motion of the oscillating body can be expressed by the following formula: θ (t) = A ₁ sinωt + ΣA _n sin (nωt + φ _n-1 ). Here, the amplitude and angular frequency of the first vibration motion are A ₁ and ω, respectively, and the amplitude and angular frequency of the nth vibration motion are An and nω, _respectively , and the relative positions of the first and nth vibration motions. _{Let the} phase difference be φ _n-1 . N is an integer of 2 or more. The value of n can be increased as long as the number of oscillators constituting the oscillator device can be increased.

The drive unit 1920 has a configuration capable of applying a driving force to the vibration system by an electromagnetic method, an electrostatic method, a piezoelectric method, or the like. In the case of electromagnetic drive, for example, a permanent magnet may be provided on at least one oscillator, and a coil for applying a magnetic field to the permanent magnet may be disposed near the oscillator, or the permanent magnet and the coil may be reversed. It is good also as arrangement of. In the case of electrostatic driving, an electrode is formed on at least one oscillating body, and an electrode that applies an electrostatic force to the electrode is formed in the vicinity of the oscillating body. In the case of piezoelectric driving, a piezoelectric element is provided in a vibration system or a support part to apply driving force. The drive control unit 1950 is configured to be able to generate a drive signal such that the vibration system vibrates in the above-described manner, and applies the drive signal to the drive unit 1920. The drive signal may be, for example, a drive signal using a signal obtained by synthesizing a sine wave using a trigonometric function table as it is, or a pulse-like drive generated based on a signal obtained by synthesizing a sine wave using a trigonometric function table It may be a signal. In the case of a drive signal obtained by synthesizing a sine wave, a desired drive signal can be obtained by adjusting the amplitude and phase of each sine wave. In the case of driving using a pulse signal, a desired drive signal can be generated by temporally changing the number, interval, width, etc. of pulses based on a signal obtained by synthesizing a sine wave.

Further, the oscillator device has a detecting means for outputting a signal according to the displacement of at least one oscillator of the one or more oscillators. In FIG. 19A, the detection means is a light receiving element 1940, and in FIG. 19B, the detection means is a piezoresistor 1970. When detecting the rocking angle of the rocking body using the piezoresistor 1970, for example, the piezoresistor 1970 is provided in the torsion spring, and the rocking body is oscillated at a certain level based on the signal output from the piezoresistor 1970. Detect time when cornering. The piezoresistor 1970 is produced, for example, by diffusing phosphorus in p-type single crystal silicon. The piezoresistor 1970 outputs a signal according to the torsion angle of the torsion spring. Therefore, when measuring the rocking angle of the rocking body, the piezoresistors 1970 are provided on a plurality of torsion springs, and the rocking angle of the rocking body is obtained based on the information on the torsion angles of the plurality of torsion springs. can do.

In the present invention, a desired resonance frequency of the oscillator device as described above is found in a short time, and typically, a steady driving frequency in actual use is appropriately set in relation to the detected resonance frequency. Is. When the resonance frequency is obtained, this frequency is typically set as a steady driving frequency. That is, in a resonance-type oscillator device that performs steady-state driving of an oscillator in the vicinity of the resonance frequency, the control means sets the steady-drive frequency to the first resonance frequency or the second resonance frequency, and Drive. However, it is also possible to control the driving means so as to drive the oscillator at a driving frequency that is intentionally removed from the resonance frequency.

In order to find out a desired resonance frequency of the oscillator device in a short time, the present invention performs the following. The drive frequency changing means included in the control means sets the drive frequency of the drive signal to be applied to the drive means at a predetermined rate of time change in a direction from the sweep start frequency away from the target resonance frequency toward the resonance frequency. Sweep. At this time, the predetermined rate of change with time is set to be large (that is, the sweep speed is high) such that the rocking state of the rocking body does not reach a steady state when driven by each driving frequency. Then, the drive frequency when the fluctuation amount based on the information output from the detection means in the drive frequency sweep reaches a peak, and a frequency closer to the sweep start frequency than the drive frequency is set as the first resonance frequency, The resonant frequency is determined either preliminary or final. Alternatively, the drive frequency is detected when the rate of change of the oscillation amount based on the information output by the detection means in the sweep of the drive frequency becomes a positive predetermined value greater than 0, and this drive frequency is set as the first resonance frequency. The resonance frequency is determined preliminary or finally. Here, since the resonance frequency is before the drive frequency at which the swing amount is maximized, the predetermined value of the change rate of the swing amount is a positive value greater than zero.

The predetermined value is set according to at least one of the resonance sharpness and the time change rate of the oscillator. In addition, the first resonance frequency may be finally determined as a target resonance frequency. However, if the following fine adjustment is performed, the desired resonance frequency can be detected more accurately. . In other words, in fine adjustment, the driving means is driven by the driving means at the first resonance frequency determined as the resonance frequency in advance and the driving frequency that differs by the frequency minimum variable accuracy before and after the first resonance frequency. . Then, the target resonance frequency is finally determined with the frequency having the maximum fluctuation amount based on the information output from the detection means at the plurality of frequencies as the second resonance frequency. This frequency minimum variable accuracy is the minimum variable by which the drive frequency changing means can change the drive frequency with sufficient accuracy, and depends on the capability of the drive frequency changing means.

Hereinafter, specific examples will be described with reference to the drawings.

(Example 1)
FIG. 1 is a block diagram illustrating a configuration example of Example 1 in which an optical deflection device using the oscillator device of the present invention is used in an optical apparatus such as an electrophotographic image forming apparatus. FIG. 2 is a diagram illustrating a configuration of the optical deflection apparatus.

As shown in FIG. 2, the optical deflector 10 has a rocking body 23 and a support portion 22, and a torsion spring 21 connects the rocking body 23 and the support portion 22. The drive unit 12 as drive means applies a driving force to the oscillator 23 by a method such as an electromagnetic method, an electrostatic method, or a piezoelectric method. For example, the electromagnetic driving means is composed of a coil and a permanent magnet. The oscillator 23 has a mirror 20 and reflects and deflects the light beam 11 from the light source 13. The reflected light of the light beam 11 by the mirror 20 is scanned by swinging the swinging body 23 by the drive unit 12, and the scanning light 14 passes through the light receiving elements 15 and 16 as detection means. The control unit 17 as control means generates a drive signal to the drive unit 12 so that the scanning light 14 maintains a predetermined scanning speed from the time when the scanning light 14 passes through the light receiving elements 15 and 16. Here, for simplification of description, a vibration system including one oscillator is described.

The relationship between the scanning light 14 and the light receiving elements 15 and 16 is as follows. FIG. 3 shows the light deflection angle by the oscillator 23 of the optical deflector 10. In the present specification, the light deflection angle and the rocking angle of the rocking body can be handled in the same way, and thus are used equally. The oscillating body 23 of the optical deflector 10 oscillates at an oscillating angle (deflection angle) of θmax, and the light receiving elements 15 and 16 are arranged where the scanning light 14 deflected at an angle θ1 smaller than θmax passes. Yes. As shown in FIG. 4 for explaining the temporal change of the deflection angle of the scanning light 14 and the timing of the detection signal, the scanning light 14 passes through the light receiving elements 15 and 16 twice in one cycle.

In the above configuration, the deflection angle θ of the optical deflector 10 shown in FIG. 4 can be expressed as follows by a function of time t.
θ (t) = θmax · sin (2πf · t) (2)
Here, f is the vibration frequency of the optical deflector.

As shown in FIG. 4, the light receiving element 16 receives light at times (light beam detection times) t40, t41, and t44, and the light receiving element 15 receives light at times t42 and t43. One period T of vibration of the oscillator 23 is
T = t44−t40 (3)
Equation (2) can be expressed using T as follows.
θ (t) = θmax · sin ((2π · t) / T) (4)

Since the time t in the equations (2) and (1) is a relative time from the scanning center, it is necessary to substitute the following value for t when obtaining θ1.
t (θ1) = t40−t45 (5)

Expression (5) is converted into expressions of t40 and t41. For this purpose, first, the following equation is obtained.
t46−t45 = T / 4 (6)
t46−t40 = (t41−t40) / 2 (7)
Then, when the equations (6) and (7) are modified and substituted into the equation (5), the following equation (8) is obtained.
t (θ1) = t40−t45 = (t46−t45) − (t46−t40) = T / 4− (t41−t40) / 2 (8)

In Expressions (6) and (7), it is assumed that the time when the maximum angle θmax is reached is the center of the detection times t40 and t41 of the light receiving element 16. Therefore, when equation (8) is input into equation (4), the following equation (9) is obtained.
θ1 = θmax · sin [{1 / 2− (t41−t40) / T} · π] (9)

When equation (9) is transformed, the following equation (10) is obtained.
θmax = θ1 / sin [{1 / 2− (t41−t40) / T} · π] (10)
Equation (10) indicates that the amplitude θmax can be obtained if the installation angle θ1 of the light receiving element 16, the interval between two consecutive detection times of the light receiving element 16 (t41−t40), and the vibration period T of the optical deflector are known. Is shown. Therefore, the detection time 19 described later and the amplitude (swing angle) θmax can be handled equally.

In the above configuration, steady driving by feedback control using the optical deflector control unit 17 of FIG. 1 is performed as follows, for example.

The waveform generation unit 108 outputs a sine wave having a frequency set to the drive frequency 109. The multiplier multiplies the sine wave generated by the waveform generation unit 108 by the amplitude control signal 111 and outputs a drive signal to the drive unit 12. The oscillator 23 is excited by the drive unit 12 to which the drive signal is applied. Thereby, the optical deflector 10 scans the light beam 11 emitted from the light source 13. As described above, the scanning light 14 is detected by the light receiving elements 15 and 16 installed at the predetermined angle θ1. The time measuring unit 18 measures the times from t40 to t41 and from t42 to t43 in FIG. These times are held in the time measuring unit 18 as the detection time 19.

Here, subtraction is performed between the detection time 19 inside the time measurement unit 18 and the target time 107. The subtraction value between the set target value and the detection time 19 is multiplied by a gain 110 as a feedback amount. The output of the gain 110 is integrated by an integrator 112 to be an amplitude control signal 111. When the detection time 19 is shorter than the target time 107, the amplitude control signal 111 is increased, and the detection time 19 is controlled to approach the target time 107. The error between the detection time 19 and the target time 107 can be reduced by amplifying and integrating the error between the detection time 19 and the target time 107 and controlling the swing amount of the swing body 23.

Further, in order to measure the amplitude change of the oscillator 23, the controller 102 detects the change in the detection time 19. At the timings t41 and t43 in FIG. 4, the controller 102 calculates the difference between the detection time 19 and the previous detection time 100, thereby detecting an amplitude change. After the calculation, the detection time 19 is stored in the previous detection time 100.

The feedback control can also be performed by adjusting the amplitude and frequency of the drive signal based on the difference between the detection time 19 and the target time 107. In this case, for example, a matrix representing the relationship between the time difference and the adjustment amount of the drive signal is obtained in advance, and the amplitude and frequency of the drive signal are adjusted. The control of the frequency can be performed using the next waveform generation unit 108 which is a drive frequency changing unit.

In order to sweep the drive frequency 109, the controller 102 holds parameters of a sweep start frequency 104, a sweep end frequency 105, a sweep speed 106, and a frequency difference 107 of the optical deflector 10. The controller 102 changes the drive frequency 109 with reference to each parameter.

The waveform generation unit 108 can be configured by, for example, an NCO (Numerical-Controlled-Oscillator). An example of NCO50 is shown in the block diagram of FIG. The digital 32-bit input is added to the signal before one sample by the one-sample delay element 52 in the adder 51 and input to the sine wave table 53 as an address. From this sine wave table 53, a 16-bit sine wave component is derived.

In this configuration, when a digital signal having a certain constant level continues to be input as an input, the output of the adder 51 has a signal having a certain positive slope according to the input level as shown in FIG. Is obtained. If the predetermined maximum value is reset to zero, a sawtooth wave 60 having a period (frequency) corresponding to the input level is obtained. By inputting this into the sine wave table 53, a sine wave is obtained. Component 61 is derived. This frequency can be changed by changing the input level.

Based on the above-described configuration and function, the operation from start to steady drive, which is a feature of this embodiment, is performed as follows.

Using the configuration of the optical deflector control unit 17 shown in FIG. 1 and FIG. 12, which is a flowchart for explaining the operation from start to steady drive, until the steady drive frequency (resonance frequency in this case) is determined. The method will be described.

First, the process of initial setting (S140) will be described. When a print processing request is received, initial setting is performed first. In order to determine the sweep start frequency and sweep speed of the drive frequency in the initial setting, the sweep start frequency 104, the sweep end frequency 105, and the sweep speed 106 are set. The sweep start frequency 104 and the sweep end frequency 105 are determined from the resonance frequency change range of the optical deflector 10. The resonance frequency change range of the optical deflector 10 is measured in advance.

The setting of the sweep speed 106 that is relatively faster than the speed at the time of the sweep described in the prior art is set based on the sweep speed and the simulation speed at the time of previous activation. FIG. 6 shows the swing angle of the swing body 23 when the sweep speed 106 of the drive frequency is changed. In FIG. 6, the speed of the sweep speed is (curve 72)> (curve 71)> (curve 70). When the value of the sweep speed is the curve 71, the swing angle increases faster and the timing at which the light-receiving elements 15 and 16 can start the measurement is earlier. However, if the value of the sweep speed is too fast as shown by the curve 72, the swing angle of the swing body 23 does not exceed the installation angle θ1 of the light receiving elements 15 and 16. Therefore, the value set for the sweep speed 106 needs to be set in a range in which the swing angle of the swing body 23 exceeds the installation angle θ1 of the light receiving elements 15 and 16 during the frequency sweep.

For example, in the initial setting, the sweep start frequency is set to 1996 Hz, the sweep end frequency is set to 2004 Hz, and the sweep speed is set to 2.8 [Hz / sec].

Next, the drive frequency sweeping method (S141, S1400 to S1403) will be described. In the drive frequency sweep, the controller 102 changes the drive frequency 109 of the waveform generation unit 108 in a predetermined direction with a predetermined change amount based on the sweep speed 106 at regular intervals. The change of the driving frequency 109 is realized by an interrupt to the controller 102.

In the controller 102, interrupt processing is executed at regular intervals (S1400). In this process, after the initial setting, the interrupt flag for driving frequency sweep is set to 1 (S141). Looking at the interrupt flag, if the flag is 1 (S1401), the controller 102 changes the drive frequency 109 of the waveform generator 108 in a predetermined direction with a predetermined change amount based on the sweep speed 106 ( S1402), interrupt processing is terminated (S1403). The interval for performing the interrupt processing is changed according to the sweep speed 106.

For example, when the sweep speed is specified as 2.8 [Hz / sec], interrupt processing is performed every 40 msec, and the frequency is changed by 0.07 Hz in the direction of increasing the frequency.

Next, the rough adjustment (S142 to S148) process will be described. Coarse adjustment is a method of calculating the resonance frequency from the maximum amplitude value during the drive frequency sweep. A rough adjustment flow will be described. A method for obtaining the maximum amplitude value at the time of sweeping the drive frequency performed during the coarse adjustment is as follows. The controller 102 looks at the update flag of the detection time 19 that the time measurement unit 18 has (S142). Continue checking the update flag repeatedly until the update flag becomes 1. When the update flag is 1, the previous measurement detection time 100 and the detection time 19 are compared (S143), and it is determined whether the detection time has decreased (S144). If the determination result is no, the detection time 19 of the time measurement unit 18 is stored in the detection time 100 of the controller 102 (S145), and the update flag of the time measurement unit 18 is viewed again (S142).

If the determination of whether or not the detection time has decreased is yes, the interrupt flag for the drive frequency sweep process is set to 0 (S146). This stops the drive frequency sweep. After stopping the frequency sweep, the parameter frequency difference 107 which is one parameter of the controller 102 is read (S147), and the resonance frequency is calculated from the drive frequency 109 where the sweep is stopped and the parameter frequency difference 107 (S148). The frequency difference 107 may be a frequency ratio. The frequency difference 107 is stored based on actual measurement data before shipment from the factory and information obtained when the user has started up before.

Next, the time displacement of the oscillator during rough adjustment will be described with reference to (a) drive frequency-time characteristics, (b) amplitude-time characteristics, and (c) detection time-time characteristics shown in FIG.

At timing t80 when the amplitude of the optical deflector exceeds the photodetector installation angle θ1, the amplitude angle θmax of the optical deflector 10 begins to exceed the angle θ1, and the detection time 19 can be measured. Although there is a timing t81 at which the drive frequency matches the resonance frequency of the optical deflector, the vibration amplitude of the optical deflector continues to increase even if the sweep is continued thereafter. This is because the Q value of the optical deflector 10 is high, and the response time until the amplitude changes corresponding to the change in frequency is long.

If sweeping is continued after timing t81, the vibration amplitude of the optical deflector becomes maximum at timing t82. After timing t82, the controller 102 detects the maximum vibration amplitude at the time of sweep at timing t83 where it is known that the detection time 19 has changed from increasing to decreasing at timing t82. Here, as shown in FIG. 7A, the controller 102 subtracts the value f86 stored in the frequency difference 107 from the frequency f84 at the timing t83 to obtain the resonance frequency f85, and ends the coarse adjustment. .

For example, it is assumed that the drive frequency at which the maximum amplitude is detected is 2001 Hz when sweeping at 2.8 [Hz / s] in the high frequency direction from 1996 Hz. When the frequency difference 107 is 0.8 Hz, the resonance frequency f85 calculated by the coarse adjustment has the following value.
Resonance frequency f85 = 2001 [Hz] −0.8 [Hz] = 2000.2 [Hz] (11)

Next, the fine adjustment (S149) will be described. In the fine adjustment, the drive frequency is changed in a narrow frequency range centered on the first resonance frequency calculated by the coarse adjustment. Then, after the change, it waits until it is stably driven, and the detection time 19 is detected. An accurate resonance frequency is measured by comparing the detection times 19 at the changed drive frequencies.

The fine adjustment will be described in detail with reference to FIG. Driving is performed at a frequency f85 obtained by rough adjustment (see FIG. 7A), a frequency f901 obtained by adding the minimum NCO frequency accuracy α to the frequency f85, and a frequency f900 obtained by subtracting α. Then, the detection time 19 at each frequency is measured. As shown in FIG. 8, the detection times corresponding to f900, f85, and f901 are t904, t902, and t903, and since t902> t903> t904, the second resonance frequency f85 is finally determined as the resonance frequency and driven. Set the frequency to f85. Here, the first resonance frequency and the second resonance frequency are the same, but of course they may be different. In addition, although driving is performed at three driving frequencies around the first resonance frequency, driving may be performed at two points or a plurality of four or more points.

For example, when the frequency minimum variable accuracy is 0.07 Hz and the frequency f85 calculated by the coarse adjustment is 2000.2 Hz, it was as follows. Detection times 19 when driven at 2000.13 Hz, 2000.2 Hz, and 2000.27 Hz were 98.5 μsec, 100 μsec, and 99 μsec. That is, the detection time 19 was the maximum at 2000.2 Hz. Accordingly, the resonance frequency is finally determined to be 2000.2 Hz, the driving frequency is set to 2000.2 Hz, and steady driving by feedback control is started. Feedback control is performed as described above. The above operation is executed by the control unit 17 which is a control unit including the waveform generation unit 108 which is a drive frequency changing unit.

The printing process after the start of steady driving in this embodiment will be described. The printing process will be described using the configuration of the image forming apparatus shown in FIG. (A) is a side view, (b) is a top view.

When a print processing request is received, the deflecting device 1000 including the optical deflector 10 reaches the steady driving state through the above-described steps, and outputs the scanning light 14. The scanning light 14 is scanned along the long axis direction of the photosensitive drum 1002.

The photosensitive drum 1002 starts to rotate, and the photosensitive drum 1002 is charged to a high potential by the charger 1001. The charged portion comes on the scanning line of the scanning light 14 by rotation, and the light source repeats turning on and off at a desired timing in order to apply the scanning light 14 to a desired position. The portion irradiated with the scanning light 14 emitted from the light source and deflected by the light deflecting device 1000 has a low potential. This is called an electrostatic latent image. The developing device 1003 develops the electrostatic latent image portion using, for example, a positively charged black one-component magnetic toner. The developed toner is transferred onto paper or the like by the transfer device 1004 to complete the printing process.

Next, a description will be given of how to obtain the difference between the drive frequency and the resonance frequency at which the vibration amplitude becomes maximum during the sweep, or the ratio between the two. In the method for determining the steady drive frequency, the difference or ratio between the drive frequency and the resonance frequency at which the amplitude is maximum during sweeping varies depending on the Q value of the optical deflector and the sweep speed of the drive frequency. Therefore, it is necessary to change the difference or ratio between the drive frequency and the resonance frequency that maximizes the amplitude during the sweep in accordance with changes in the Q value and the sweep speed.

The Q value will be explained. As shown in FIG. 10, the vibration amplitude of the optical deflector 10 changes according to the change in frequency. The drive frequency at which the vibration amplitude is maximized is the resonance frequency f1102. Based on the steady drive frequencies f1103 and f1104 when the amplitude energy becomes the half value 1101 of the maximum value 1100, the Q value can be obtained from the following equation.
Q = resonance frequency f1102 / (frequency f1104−frequency f1103) (12)
When a vibration body having a high Q value is steadily driven, once vibration is started, the vibration continues for a long time. Also, the higher the Q value, the greater the delay between applying an arbitrary drive voltage and obtaining the vibration amplitude for that drive voltage.

FIG. 11 (a) shows the drive frequency-time characteristics and amplitude-time characteristics of the oscillator when the Q values are different for the same oscillator (for example, the Q value varies with temperature). Q1 <Q2, and the drive frequency is swept at the same sweep speed in each state. The amplitude characteristic of Q1 is indicated by a curve 120, and the amplitude characteristic of Q2 is indicated by a curve 121. As can be seen from the figure, the maximum amplitude detection times are t122 and t123, respectively, and the drive frequencies at the time of maximum amplitude detection are f124 and f125, respectively. When the Q value is higher, the drive frequency when the peak is detected is higher, so the time t123 until the peak detection becomes longer. The resonance frequency is f126, and the frequency difference 107 used when obtaining the first resonance frequency or the steady drive frequency is (f125−f126) when Q1 and (f124−f126) when Q2.

As can be seen from the above, it is necessary to change the frequency difference 107 when the Q value changes. The frequency difference 107 needs to be increased as the Q value increases. When the frequency difference 107 is a frequency ratio, the ratio ratio increases as the Q value increases. Such a relationship between the frequency difference 107 or the frequency ratio and the Q value may be measured in advance and stored as a calibration curve, and the frequency difference 107 or the frequency ratio may be changed each time.

On the other hand, FIG. 11B shows drive frequency-time characteristics and amplitude-time characteristics when the drive frequency sweep speed of the optical deflector is changed. The amplitude characteristic at the sweep speed 134 is indicated by a curve 131, and the amplitude characteristic at the sweep speed 135 is indicated by a curve 130. The sweep speed is 134> 135. The maximum amplitude detection time at the sweep speed 134 is t133, and the drive frequency is f136. The maximum amplitude detection time at the sweep speed 135 is t132, and the drive frequency is f137. The faster the sweep speed, the longer the time until peak detection. The resonance frequency is f138, and the frequency difference 107 is (f136−f138) when the sweep speed is 134, and (f137−f138) when the sweep speed is 135.

As can be seen from the above, it is necessary to change the frequency difference 107 even when the sweep speed for sweeping the drive frequency is changed. As the sweep speed increases, the frequency difference 107 needs to be increased. When the frequency difference 107 is a frequency ratio, the ratio increases as the sweep speed increases.

The relationship between the frequency difference 107 or the frequency ratio and both the Q value and the sweep speed is measured in advance and stored as a calibration curve, etc., and the frequency difference 107 or the frequency ratio is determined according to the Q value and the sweep speed at that time. Can also be changed. In the above example, the drive frequency is swept from the sweep start frequency separated from the resonance frequency to the low frequency side, but may be swept from the sweep start frequency separated from the resonance frequency to the high frequency side. However, in this case, in the above example, the magnitude relationship between the drive frequencies f124, f125, f136, f137 and the resonance frequencies f126, f138 at the time of detecting the maximum amplitude is reversed, so that the calculation according to the calculation is performed accordingly. It is necessary to calculate the resonance frequency.

If the technique of the present embodiment is used, a frequency that can be regarded as the resonance frequency of the oscillator in a relatively short time (the above-described first or second resonance frequency) is found, and a steady driving frequency in actual use is set. be able to. Thus, it is possible to provide a technique for detecting the resonance frequency of the oscillator device in a short time and shortening the startup time of the system using the oscillator device. For example, when applied to a printer, there is no longer a situation where a user waits for a long time from a print request to print execution. For this reason, it is not necessary to maintain the rocking state at all times, and it is only necessary to start the system upon request, so that power consumption is reduced.

(Example 2)
FIG. 13 is a block diagram showing a configuration example of Example 2 in which an optical deflection apparatus using the oscillator device of the present invention is used in an optical apparatus such as an electrophotographic image forming apparatus.

In the first embodiment, as shown in FIG. 7, until the resonance frequency of the optical deflector is calculated, the sweeping drive frequency passes the resonance frequency at timing t81. However, if the detection time change rate 87 when passing the resonance frequency shown by the broken line in FIG. 7 (c) is known in advance, by stopping the operation of sweeping the drive frequency of the optical deflector when the change rate is detected, Resonance frequency can be detected. Then, steady driving at this frequency becomes possible.

In the first embodiment, the parameter of the difference 107 or the ratio between the drive frequency and the resonance frequency at which the amplitude becomes maximum during the sweep is stored in the controller 102. Instead, in the second embodiment, as shown in FIG. 13, the detection time change rate 170 when the resonance frequency is passed during the sweep is stored in the controller 102. Other points are the same as in the first embodiment.

The operation of the second embodiment different from the first embodiment will be described with reference to FIG. 13 showing the configuration of the optical deflector control unit 17 and FIG. 16 of the flowchart.

First, regarding the initial setting, the second embodiment differs from the first embodiment in a part of the coarse adjustment process (S212 to S215). Here, as in the first embodiment, the interrupt flag for sweeping the drive frequency is set to 1 (S211). Next, the controller 102 looks at the update flag of the detection time 19 that the time measurement unit 18 has (S212). Continue checking the update flag repeatedly until the update flag becomes 1.

When the update flag is 1, the detection time change rate is calculated from the previous measurement detection time 100 and the detection time 19 (S213). Then, the calculation result is compared with the detection time change rate 170 which is a parameter of the controller 102 (S214). As a result of the comparison, if the calculated result and the parameter detection time change rate 170 do not match or the difference is equal to or greater than a predetermined value, the detection time 19 possessed by the time measurement unit 18 is stored in the detection time 100 of the controller 102, and the time again The update flag of the measurement unit 18 is viewed (S212). As a result of the comparison, if the calculation result and the parameter detection time change rate 170 match or the difference is equal to or smaller than a predetermined value, the driving frequency sweep interrupt flag is set to 0 (S216). Thereafter, fine adjustment is performed in the same manner as in the first embodiment (S217), and the steady drive frequency is determined.

For example, it is assumed that the detection time change rate 170 of the positive predetermined value of the controller 102 is 2.5 × 10 ⁻⁴ . When sweeping from 1996Hz in the high frequency direction 2.8 [Hz / s], the rate of change in detection time gradually increases, and the rate of change calculated at 2000.2Hz is within 1% of the rate of change in detection time 170. Suppose that At that time, the sweep is stopped and fine adjustment is performed as necessary. After steady driving, the printing process is performed in the same manner as in the first embodiment.

FIG. 14 shows time changes such as the frequency during the coarse adjustment. (A) is a drive frequency-time characteristic, (b) is an oscillation amplitude-time characteristic, and (c) is a detection time-time characteristic.

At timing t180 when the amplitude of the optical deflector exceeds the photodetector installation angle θ1, the drive frequency matches the resonance frequency of the optical deflector. At this time, since the detection time change rate matches the parameter detection time change rate 170, it can be recognized that the drive frequency has reached the resonance frequency.

A method for obtaining the detection time change rate 170 will be described. The detection time change rate 170 also changes depending on the Q value of the optical deflector and the sweep speed of the drive frequency. Therefore, it is necessary to change the detection time change rate 170 according to the change in the Q value and the sweep speed.

FIG. 15A shows the characteristic of the detection time change rate 170 (Q value-detection time change rate characteristic) when the Q value of the optical deflector changes. It shows that the detection time change rate 170 increases as the Q value increases. In Fig. 15 (a), which shows the drive frequency-time characteristics and amplitude-time characteristics of the oscillators when the Q values are different for the same oscillator, Q1 <Q2, and the drive frequency is swept at the same sweep speed in each state. is doing. The amplitude characteristic of Q1 is indicated by a curve 191 and the amplitude characteristic of Q2 is indicated by a curve 192. The amplitude change rate, that is, the detection time change rate 170 when passing through the resonance frequency f190 has a slope of a straight line 193 for the Q1 optical deflector and a slope of a straight line 194 for the Q2 optical deflector. Thus, as the Q increases, it is necessary to increase the detection time change rate 170 when passing through the resonance frequency.

Next, the sweep speed-detection time change rate characteristic will be described. FIG. 15B shows drive frequency-time characteristics and amplitude-time characteristics when the drive frequency sweep speed of the optical deflector is changed. The amplitude characteristic at the sweep speed 205 is indicated by a curve 201, and the amplitude characteristic at the sweep speed 206 is indicated by a curve 202. The sweep speed is 206> 205. When the sweep speed 205 is slow, the change rate of the detection time passing through the resonance frequency f200 becomes the slope of the straight line 203. When the sweep speed 206 is high, the change rate of the detection time passing through the resonance frequency f200 is a slope of the straight line 204. The faster the sweep speed, the larger the amplitude change rate when passing through the resonance frequency. Therefore, as the sweep speed increases, it is necessary to increase the detection time change rate 170 when passing through the resonance frequency.

Also in Example 2, the drive frequency was swept from the sweep start frequency that was distant from the resonance frequency toward the low frequency side. However, also in this embodiment, it is possible to sweep from a sweep start frequency that is farther to the high frequency side than the resonance frequency.

Even using the technology of this embodiment, a frequency that can be regarded as the resonance frequency of the oscillator in a relatively short time (the above-described first or second resonance frequency) is found, and a steady drive frequency in actual use is set. can do.

(Example 3)
A third embodiment in which the light deflecting device according to the present invention is used in a drawing apparatus or an image forming apparatus in a moving image viewing apparatus will be described.

The configuration of this embodiment is as follows. As shown in FIG. 17, there are an optical deflector 153 and an optical deflector 158 whose rotational axis is installed perpendicular to the rotational axis of the optical deflector 153. The configuration for scanning the light from the light source 150 is the same as that in the above embodiment, and for the optical deflector 153, a drive unit 152, a control unit 151, and light detection units 154 and 155 are provided. For the optical deflector 158, a drive unit 157, a control unit 156, and light detection units 159 and 1510 are provided.

The scanning light deflected by the optical deflector 153 and the optical deflector 158 is shown in FIG. The amplitude of the optical deflector 158 can be measured from the detection times of the light detection units 159 and 1510. The amplitude of the optical deflector 153 can be measured from the detection times of the light detection units 154 and 155.

First, without driving the optical deflector 153, the steady drive frequency of the optical deflector 158 is determined by the same method as in the above embodiment. Next, the steady drive frequency of the optical deflector 153 is determined by the same method as in the above embodiment while driving the optical deflector 158 at the determined steady drive frequency.

A moving image is projected on the screen 1511 by constantly driving the two optical deflectors. In FIG. 18, reference numeral 1610 denotes a scanning area. According to the present embodiment, it is possible to detect the resonance frequency of the optical deflector in a short time, and to shorten the startup time of the image drawing apparatus which is a system using the optical deflection apparatus of the present invention.

The optical apparatus of the present invention such as the apparatus of FIG. 9 or the apparatus of Example 3 includes the light deflection apparatus of the present invention and a light irradiation object such as a photosensitive drum or a screen. The light deflection apparatus generates a light beam. The light beam from the means is deflected, and at least a part of the light beam is incident on the light irradiation object.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of an optical apparatus using an optical deflecting device according to a first embodiment using an oscillator device of the present invention. FIG. 2 is a configuration diagram of the light deflection apparatus in FIG. The figure explaining the deflection angle of an optical deflector. The figure explaining the time change of the deflection angle of scanning light, and the timing of the detection signal. The figure explaining NCO of a drive frequency change means. The figure explaining the rocking | swiveling angle of the rocking | swiveling body at the time of sweep speed change. The figure explaining each characteristic at the time of drive frequency sweep. The figure explaining a drive frequency fine adjustment process. 1 is a configuration diagram illustrating an example of an image forming apparatus. The figure explaining the steady drive frequency-amplitude characteristic of a resonance type optical deflector. The figure explaining the Q value characteristic of the resonance frequency and the maximum amplitude detection frequency, and the sweep speed characteristic of the resonance frequency and the maximum amplitude detection frequency. FIG. 3 is a diagram illustrating a flowchart of the first embodiment. FIG. 6 is a configuration diagram of an optical apparatus that uses the optical deflecting device of Example 2 using the oscillator device of the present invention. FIG. 6 is a diagram for explaining each characteristic until a resonance frequency is determined in the second embodiment. The figure explaining the characteristic of the detection time change rate at the time of Q value and resonance frequency passage, and the sweep speed and the detection time change rate at the time of resonance frequency passage. FIG. 9 is a diagram illustrating a flowchart of the second embodiment. FIG. 6 is a configuration diagram of an image drawing device of Example 3 using the oscillator device of the present invention. FIG. 6 is a diagram illustrating scanning light according to the third embodiment. The figure explaining the basic composition of the oscillator device of the present invention. The block diagram explaining a prior art example.

Explanation of symbols

10, 153, 158, 1000 Optical deflection device (optical deflector)
12, 152, 157, 1920 Drive means (drive part)
13, 150, 1931 Light beam generation means (light source)
15, 16, 154, 155, 1510, 1511, 1940, 1970 Detection means (light receiving element, light detection unit, piezoresistor)
17, 151, 156, 1950 Control means (control unit)
20 mirror
23, 1901, 1902, 1903 Oscillator
108 Drive frequency change means (waveform generator)
1002, 1511 Light irradiation object (photosensitive drum, screen)

Claims (10)

At least one oscillatingly supported oscillator having a resonant frequency;
Detecting means for detecting information related to the swing amount of the swing body;
Drive means for driving the oscillator;
Control means including drive frequency changing means for changing the drive frequency of the drive signal applied to the drive means;
Have
The control means includes
The drive frequency changing means sweeps the drive frequency at a predetermined time change rate in a direction from the sweep start frequency away from the resonance frequency toward the resonance frequency,
In the sweep of the drive frequency, the drive frequency when the fluctuation amount based on the information output by the detection means reaches a peak is detected, and a frequency closer to the sweep start frequency than the drive frequency at the peak is determined. Determining the resonance frequency as a resonance frequency of 1 in a preliminary or final manner,
An oscillator device characterized by the above. At least one oscillatingly supported oscillator having a resonant frequency;
Detecting means for detecting information related to the swing amount of the swing body;
Drive means for driving the oscillator;
Control means including drive frequency changing means for changing the drive frequency of the drive signal applied to the drive means;
Have
The control means includes
The drive frequency changing means sweeps the drive frequency at a predetermined time change rate in a direction from the sweep start frequency away from the resonance frequency toward the resonance frequency,
When the change rate of the fluctuation amount based on the information output by the detection means in the sweep of the drive frequency becomes a predetermined positive value greater than 0, and the change rate becomes the predetermined value The drive frequency of the first resonance frequency, the resonance frequency is determined preliminary or finally,
An oscillator device characterized by the above. 3. The oscillator device according to claim 1, wherein the predetermined value is set according to at least one of a resonance sharpness of the oscillator and the time change rate. The control means includes
With the first resonance frequency and the drive frequency different by the frequency minimum variable accuracy of the drive frequency changing means before and after the first resonance frequency, the drive means drives the oscillator.
The resonance frequency is finally determined by setting the frequency with the maximum fluctuation amount based on information output from the detection means at the plurality of frequencies as the second resonance frequency,
4. The oscillator device according to claim 1, wherein the oscillator device is provided. A resonance type oscillator device for steady driving of an oscillator in the vicinity of the resonance frequency,
The control means sets the steady drive frequency to the first resonance frequency or the second resonance frequency.
5. The oscillator device according to claim 1, wherein the oscillator device is provided. The oscillator device according to any one of claims 1 to 5, and a light beam generating means for generating a light beam,
The oscillating body has a mirror, and the light beam generated by the light beam generating means is reflected and deflected by the mirror,
The detecting means includes light detecting means arranged to detect the deflected light beam at a position of a predetermined deflection angle;
The control means detects a swing amount of the swing body or a change rate of the swing amount based on an interval of a light beam detection time of the light detection means;
An optical deflector characterized by that. The light deflection apparatus according to claim 6, and a light irradiation object,
The light deflecting device deflects the light beam from the light beam generating means, and causes at least a part of the light beam to enter the light irradiation object.
An optical apparatus characterized by that. Resonance in an oscillating body device having at least one oscillating body having a resonance frequency and supported so as to be able to oscillate, detecting means for detecting information related to an oscillating amount of the oscillating body, and driving means for driving the oscillating body. A method for detecting a frequency,
Sweeping the drive frequency at a predetermined rate of time change in a direction from the sweep start frequency away from the resonance frequency toward the resonance frequency;
Detecting the drive frequency when the fluctuation amount based on the information output by the detection means in the sweep of the drive frequency reaches a peak;
The frequency that is closer to the sweep start frequency than the driving frequency at the time of the peak as a first resonance frequency, the resonance frequency is determined preliminary or finally,
including,
A resonance frequency detection method characterized by the above. Resonance in an oscillating body device having at least one oscillating body having a resonance frequency and supported so as to be able to oscillate, detecting means for detecting information related to an oscillating amount of the oscillating body, and driving means for driving the oscillating body. A method for detecting a frequency,
Sweeping the drive frequency at a predetermined rate of time change in a direction from the sweep start frequency away from the resonance frequency toward the resonance frequency;
Detecting the drive frequency when the change rate of the swing amount based on the information output by the detection means in the sweep of the drive frequency becomes a predetermined positive value greater than 0;
The drive frequency when the rate of change has become a predetermined value as a first resonance frequency, the resonance frequency is determined preliminary or finally,
including,
A resonance frequency detection method characterized by the above. Driving the oscillating body to the driving means at the first resonance frequency and a drive frequency that differs by a frequency minimum variable accuracy before and after the first resonance frequency;
A step of finally determining the resonance frequency with a frequency having the maximum fluctuation amount based on information output from the detection means at the plurality of frequencies as a second resonance frequency;
including,
10. The resonance frequency detection method according to claim 8 or 9, wherein:

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