CN201210199Y - Micro-computer electrically scanning controller with fixed scanning frequency - Google Patents

Abstract

The utility model relates to a microcomputer electric-scanning controller with a fixed scanning frequency, and in particular relates to a controller of a microcomputer electric (vibration-typed) reflector in a dual-direction laser scanning device of a laser printer; the vibration amplitude is adjusted with the original resonance frequency of the microcomputer electric reflector, so that the scanning data is outputted with the frequency that is transmitted by a laser light source that is previously determined by the laser printer and from the effective scanning visual window of a fixed time interval, thereby simplifying the structure of the controller, and realizing the high-precise scanning effect.

Description

The MEMS scan controller of inherence frequency

Technical field

The micro electronmechanical scan controller of the relevant a kind of inherence frequency of the utility model, relate in particular to a kind of controller and control method thereof that is used for the mems mirror (being called for short MEMS mirror) of two-way laser scanister, in the time interval that fixing LASER Light Source is sent, scan with the natural reonant frequency of utilizing mems mirror.

Background technology

At present at laser scanning device (laser scanning unit, be called for short LSU) mostly use polygonal rotating mirror (Polygon Mirror) to control the scanning of laser beam with high speed rotating, but because polygonal rotating mirror is to use hydraulic-driven, itself because rotating speed is limited, price is high, loud, start and to wait factor slowly, can't meet gradually at a high speed and high-precision requirement.In recent years, mems mirror (micro-electronic-mechanic system oscillatory mirror with torque oscillation device (torsion oscillators), be called for short MEMS mirror) begun to develop, to can be applicable to laser scanning device (the laser scanning unit of image system (imaging system), scanner (scanner) or laser printer (laser printer) future, be called for short LSU), its scan efficiency (Scanning efficiency) can be higher than traditional polygonal rotating mirror.

Mems mirror (MEMS mirror) in MEMS laser scanning device (MEMS LSU) is made of torque oscillation device and mirror surface, and controlled by MEMS scan controller (MEMS scan controller); Mems mirror drives minute surface by resonant field and vibrates back and forth with the axle center left and right directions; When the minute surface of laser beam directive mems mirror, minute surface is reflected on the various angle of mems mirror central shaft to scan the laser beam on the minute surface that incides mems mirror by time dependent rotational angle.Because mems mirror can be ignored the influence of optical wavelength, thereby can reach the characteristics of high-res and big rotational angle, make it be widely used on commerce, science and the commercial Application, as U.S. Pat 5,408,352, US5,867,297, US6,947,189, US7,190,499, US2007/063134; Taiwan patent TW M253133, TW I283952; Jap.P. JP 2006-201350, JP63-314965 etc.Because mems mirror vibrates back and forth with the axle center left and right directions, use bilateral scanning for improving scan efficiency, promptly when the forward synchronous vibration,, scan with the regular hour interval; And when reverse synchronous vibration, with the regular hour interval, scan, to constitute two-way laser scanister (bi-direction laserscanning unit).

Because mems mirror vibrates back and forth with resonance mode, the angle of its vibration and the stable scanning degree of accuracy that will influence laser scanning device, on the controller of the two-way laser scanister of mems mirror, existing technology focuses on the stable control of mems mirror, as adjust the mems mirror resonant frequency, adjust the mems mirror operating angle, or utilize Voltage-Controlled oscillation circuit (voltage controlled oscillator, VCO) to adjust frequency, as U.S. Pat 2005/0280879, US2006/00139113, US2005/0139678, US2007/0041068, US2004/0119002, US7,304,411, US5,121,138; Jap.P. JP63-314965 etc.

Yet two-way MEMS laser scanning device primary demand, 600DPI (dot per inch with the A4 size, point/inch) precision is an example, when each scanning direction, must send the luminous point (lightspot) of 5102 laser beams, make these 5102 luminous points can be at effective scanning form (imaging interval, scanning window) complete sending in, and can not cause the effective scanning form to move because of the frequency variation of mems mirror or amplitude change, cause 5102 luminous points skews or can not complete imaging on object.Therefore calculating the frequency of mems mirror, send the correct signal of laser controller of laser beam, then is one of major control emphasis of prior art.

Yet, mems mirror uses spring or magnetic force to form resonance and the vibration eyeglass, so that laser beam is scanned, because indivedual mems mirrors structurally have a little difference, its intrinsic resonant frequency is also different, as U.S. Pat 2006/0279364, US6,891,572, US6,870,560, US6,987,595, US6,838,661, US2006/0117854 disclose to use reference table, scan synchronizing signal, counter or measure control mems mirror such as photo switches, photo sensors position; BrP GB2378261 discloses the predictive mode technology (prediction molding) of using; Jap.P. JP2226114 uses the relative method of two voltages etc.Yet these are all quite complicated on control structure, use complicated calculating and storer, to attempt solving the stability of mems mirror vibration, and control have individual difference the mems mirror resonant frequency, MEMS laser scanning device make its vibration become unanimity, so that can scan in the effective scanning form accurately.

The utility model can be in the effective scanning form, natural frequency according to mems mirror, adjust amplitude and control its stable oscillation, but the data transfer time interval (being transmitted frequency) of devices such as fixed laser printer like this, multifunctional paper feeding machine, and avoid constantly adjusting the situation of MEMS laser scanning device transmitted frequency, thus, utilize the MEMS laser scanning device that MEMS scan controller constituted of the utility model manufacturing, can simple and easyly be installed in the laser printer, multifunctional paper feeding machine of different label patterns and use.

Summary of the invention

The utility model fundamental purpose is to provide a kind of MEMS scan controller of inherence frequency, being installed in the MEMS laser scanning device, and is applied to the device such as laser printer, multifunctional paper feeding machine of bilateral scanning; By this MEMS scan controller mems mirror is vibrated with vibration frequency, and the vibration amplitude of control mems mirror, so that laser beam can correctly scan in effective scanning area.

For achieving the above object, a kind of technical scheme that the utility model provides is, a kind of MEMS scan controller of inherence frequency, it is applied to laser scanning device, this laser scanning device comprises: a LASER Light Source its in order to produce laser beam; One mems mirror it utilize resonance mode driving catoptron with forward scan and reverse scan laser beam to be scanned on object; It receives one photo switches, photo sensors scanning ray and light signal is transformed into the photoelectricity sensing signal; It is transformed into the one scan eyeglass scanning ray and makes its angle and time linear; And a laser controller its control described LASER Light Source with frequency preset and time interval and send laser beam; Described MEMS scan controller is a vibration amplitude of adjusting mems mirror with the natural reonant frequency of mems mirror, and it comprises a logical block, a control signal output unit, reaches a bridge circuit, wherein:

Described logical block receives the photoelectricity sensing signal that described photo switches, photo sensors produces, and the interval time of calculating each photoelectricity sensing signal, gives described bridge circuit with the modulating signal that produces described mems mirror; And the amplitude difference signal that produces described mems mirror gives described control signal output unit;

Described control signal output unit receives the amplitude difference signal of described logical block and converts it to the stabilization signal of the described laser controller of control;

Described bridge circuit receives the modulating signal of described logical block and to the drive signal of converting to drive the vibration of described mems mirror;

By this, laser scanning device is sent scan-data according to frequency preset and time interval in the effective scanning form.

Another technical scheme is, a kind of MEMS scan controller of inherence frequency, it is applied to laser scanning device, this laser scanning device comprise a LASER Light Source its in order to produce laser beam; One mems mirror it utilize resonance mode driving catoptron with forward scan and reverse scan laser beam to be scanned on object; Two photo switches, photo sensors, it receives scanning ray and light signal is transformed into the photoelectricity sensing signal; It is transformed into the one scan eyeglass scanning ray and makes its angle and time linear; And a laser controller its control described LASER Light Source with frequency preset and time interval and send laser beam; Described MEMS scan controller is a vibration amplitude of also stablizing mems mirror in order to the natural reonant frequency of detecting mems mirror, and it comprises a logical block, a control signal output unit, reaches a bridge circuit, wherein:

Described logical block receives the photoelectricity sensing signal that described two photo switches, photo sensors produce, and calculates the interval between each photoelectricity sensing signal, gives described bridge circuit with the modulating signal that produces described mems mirror; And produce the stable signal of described mems mirror and give described control signal output unit;

Described control signal output unit receives the stable signal of the mems mirror of described logical block and converts it to the stabilization signal of the described laser controller of control;

Described bridge circuit receives the modulating signal of described logical block, to the drive signal of converting to drive the vibration of described mems mirror;

By this, laser scanning device is sent scan-data according to frequency preset and time interval in the effective scanning form.

Scan mirror can be made of one chip, two-chip type eyeglass or two above eyeglasses, the MEMS scan controller that the utility model is related, can apply to the MEMS laser scanning device of monolithic, two or two above scan mirror, if make resolution better, can use two-chip type eyeglass or two above eyeglasses.When using the two-chip type eyeglass, wherein, first scan mirror is proofreaied and correct scanning ray the relation that becomes linear session, second scan mirror or more scan mirror then can be according to the natural reonant frequency adjustment of different mems mirrors and the relative positions of first scan mirror, further the revisal scanning ray becomes the relation of linear session, with the predetermined scan-data of transmission correct in the effective scanning form.

The beneficial effects of the utility model are to adjust vibration amplitude by the natural reonant frequency of MEMS scan controller control mems mirror, so that send in the effective scanning form in frequency that scan-data sends according to the default fixing LASER Light Source of laser printer and set time interval, so can simplify the structure of controller, reach high-precision scanning effect.

Description of drawings

Fig. 1 is the utility model two-way laser scanister synoptic diagram;

Fig. 2 sends photoelectricity sensing signal and time relation figure for the angle of the utility model mems mirror reflector laser light and time relation and photo switches, photo sensors;

Fig. 3 is a MEMS scan controller synoptic diagram of the present utility model;

Fig. 4 is the utility model photoelectricity sensing signal, scanning ray angle and time relation figure;

Fig. 5 receives laser controller signal and photo switches, photo sensors signal and sends the first modulating signal graph of a relation for the utility model MEMS scan controller;

Fig. 6 is the utility model first modulating signal, second modulating signal and the 3rd modulating signal graph of a relation;

Fig. 7 is the utility model MEMS scan controller control flow chart;

Fig. 8 is the utility model scan-data control flow chart;

Fig. 9 is that the utility model scan mirror is to luminous point revisal key diagram;

Figure 10 is the MEMS scan controller synoptic diagram of the utility model second embodiment;

Figure 11 is photoelectricity sensing signal and the time relation figure of the utility model second embodiment;

Figure 12,13,14 is that the mems mirror natural reonant frequency of scan mirror of the two eyeglass formulas of the utility model the 3rd embodiment changes and scanning angle (two scan mirror distance) graph of a relation.

Description of reference numerals:

10-mems mirror (MEMS mirror); 11-LASER Light Source (pre-scan laser); 111-laser beam (Laserlight); 113 (a, b, c), 114,115 (a, b)-scanning rays (Scanning light); 13-scan mirror (post-scan lens); 131-first scan mirror (first scan lens); 132-second scan mirror (secondscan lens); 14a, 14b-photo switches, photo sensors (PD detector); 15-object (target drum); 21-MEMS scan controller (MEMS scan controller); 211-logical block (Control logic); 212-bridge circuit (Bridge circuit); 213-control signal output unit (Control signal output unit); 23-laser controller (laser controller); 311-drive signal (driving signal); 312a, 312b-photoelectricity sensing signal (PDsignal); 313-starts enable signal (ENB signal); 314-adjusts signal (Adjust signal); 315-stabilization signal (Stable signal); 316a-first modulating signal (PWM1 signal); 316b-second modulating signal (PWM2signal); 316c-the 3rd modulating signal (PWM3 signal); 316d-amplitude difference signal (amplitude errorsignal; 317-trigger pip (trigger signal); 318-frequency errors signal (frequency errorsignal); 319-scan-data (Data string).

Embodiment

Below in conjunction with accompanying drawing above-mentioned and other feature and advantage of the present utility model are elaborated.

For MEMS laser scanning device, as shown in Figure 1, wherein the laser controller of LASER Light Source Stimulated Light printer or multifunctional paper feeding machine is controlled, when laser controller sends scan-data, with f _DataTransmitted frequency produces the laser beam that is interrupted with data by LASER Light Source, the reflection minute surface of directive mems mirror, mems mirror makes minute surface with forward and reversal of vibrations laser beam scanning be become scanning ray with resonant frequency (resonant frequency), by imaging on object after the scan mirror correction.Because the laser controller of LASER Light Source Stimulated Light printer or multifunctional paper feeding machine is controlled, in laser printer or multifunctional paper feeding machine design with changeless f _DataWhen transmitted frequency was sent scanning with laser beam, for the laser printer or the multifunctional paper feeding machine of this inherence frequency, MEMS scan controller of the present utility model can correctly scan laser beam in effective scanning area.Because indivedual mems mirrors structurally have a little difference, the natural reonant frequency of its each mems mirror (inherence resonant frequency) f ₀Be not identical, but in the margin tolerance of making, but small difference then has evident difference generation or luminous point skew generation by the light path amplification on the object of imaging.When mems mirror makes laser beam drop on effective scanning area interscan with forward and reversal of vibrations (swing), be called effective scanning form (scanning window) scanning, laser beam is scanning ray after scanning, scanning ray is by scan mirror imaging on object; The scanning ray that surpasses the effective scanning form is then detected by photo switches, photo sensors.Mems mirror is controlled by MEMS scan controller then, and MEMS scan controller control mems mirror is with its natural reonant frequency vibration, and the amplitude of control vibration, makes it can be with predetermined angular vibration.After mems mirror was stable, MEMS scan controller can send the laser controller that stabilization signal is informed laser printer or multifunctional paper feeding machine, sent the time interval of scan-data and with the frequency f of predetermined scan-data by laser controller _DataSend scan-data, LASER Light Source is then sent laser beam according to scan-data, to produce the luminous point quantity that meets the resolution requirement in the effective scanning form.

Since scanning form in, the vibration frequency of mems mirror need with the scan-data frequency f of laser controller _DataMatch, as the sweep frequency f of laser controller _DataWhen having departed from former setting value, the signal that the control signal output unit can further send the transmitted frequency mistake carries out sweep frequency f by laser controller _DataAdjustment.

Because mems mirror is with f ₀Frequency is vibrated back and forth, vibration vibration from right to left more from left to right, the time of finishing one-period is T, the angle of scanning is θ, the angle θ of this scanning and time relation are sine relation, as shown in Figure 2, for avoiding scanning distortion, in the time T of one-period with near two sections time: a～b of straight line and b '～a ' for sending the time interval of laser beam.As shown in Figure 4, T ₂With T ₄Be respectively the time of forward scan and reverse scan, and be near two periods of straight line.T ₁, T ₂, T ₃, T ₄Between the relation as follows:

$T_1={\sin }^{-1}\left(\frac{{\mathrm{\θ}}_p}{{\mathrm{\θ}}_c}\right)\·\frac{1}{2\mathrm{\π}{f}_0}-{\sin }^{-1}\left(\frac{{\mathrm{\θ}}_n}{{\mathrm{\θ}}_c}\right)\·\frac{1}{2\mathrm{\π}{f}_0}---\left(1\right)$

${\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="Y200820115938E00201.png"\; state="\{\{state\}\}">T</figure-callout>}}_2=2{\sin }^{-1}\left(\frac{{\mathrm{\&theta;}}_n}{{\mathrm{\&theta;}}_c}\right)\&CenterDot;\frac{1}{2\mathrm{\&pi;}{f}_0}---\left(2\right)$

${\mathrm{<figure-callout\; id="3"\; label="T"\; filenames="Y200820115938E00201.png"\; state="\{\{state\}\}">T</figure-callout>}}_3=\frac{1}{2}(T-2T_2)---\left(3\right)$

T ₄＝T ₂ (4)

Wherein, T ₁Be delay time, T ₂Be the time of forward scan, T ₃Be delay time, T ₄Be the time of reverse scan, f ₀Be the natural frequency of mems mirror, 2 θ _cBe the mems mirror scanning angle, 2 θ _pBe the photo switches, photo sensors angle, 2 θ _nBe the effective scanning angle, what constituted is the effective scanning form.

For 600 DPI, A4 size, when producing 5102 luminous points, can be as if every row:

$f_{\mathrm{data}}=\frac{1}{{\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="Y200820115938E00201.png"\; state="\{\{state\}\}">T</figure-callout>}}_2}5102---\left(5\right)$

f _DataBy laser printer or multifunctional paper feeding machine are preestablished, can calculate the time T of forward scan by Eq. (5) (be formula (5), hereinafter also representation formula of Eq.) ₂Or the time T of reverse scan ₄, after the mems mirror vibration was stable, scanning ray was at 2 θ _nBe the effective scanning angle, then can transmit scan-data by laser controller.At the scanning ray of effective scanning angle, form by the mems mirror scanning reflection, as shown in Figure 2, the angle of mems mirror changes in the sinusoidal curve mode in time, only is than near straight line between a～b or b '～a ', is the effective scanning form.Yet, near a point or near b point place (near a ' point or near b ' point), its angular velocity gives revisal with different near the angular velocity of a-b center by scan mirror, makes scanning ray and time linear.

For making the utility model more clear and definite full and accurate, details are as follows to cooperate following preferred embodiment diagram:

＜embodiment one 〉

Present embodiment is applied to the MEMS laser scanning device of a photo switches, photo sensors; As shown in Figure 1, for MEMS laser scanning device, LASER Light Source 11 Stimulated Light controllers 23 are controlled in the device, when laser controller 23 sends scan-data 319, then produce laser beam 111 by LASER Light Source 11; The mirror surface of laser beam 111 directive mems mirrors 10, mems mirror 10 is with f ₀Natural reonant frequency makes minute surface with forward and reversal of vibrations; The present embodiment frequency of utilization is that 2500 ± 3%HZ (individual other natural reonant frequency is in this scope), maximum scan angle are ± 23 ° mems mirror 10; 111 of laser beams are with θ _c=± 23*2 ° angle scanning becomes right side edge scanning ray 115a to the light between the left side edge scanning ray 115b; 2 θ _nThe scanning ray of scope is made of light in 113a to the 113b scope, and this is the effective scanning form; In the present embodiment, photo switches, photo sensors 14a is located at θ _p=± 21*2 ° of angle place makes scanning ray 114a be detected by photo switches, photo sensors 14a.Photo switches, photo sensors 14a can receive scanning ray 114a and light signal is transformed into electrical trigger pip.Scanning ray 113a to 113b then by scan mirror 13 in object 15 as photosensitive drums on imaging.For keeping 2 θ _cStablizing of angle, 10 of mems mirrors are controlled by MEMS scan controller 21, MEMS scan controller 21 can send drive signal 311 vibrates mems mirror 10, when mems mirror 10 vibration amplitudes are excessive, may command MEMS scan controller 21 makes and sends drive signal 311, in like manner, when mems mirror 10 vibration amplitudes were too small, may command MEMS scan controller 21 made and sends drive signal 311.

As shown in Figure 3, MEMS scan controller 21 comprises a logical block 211, a control signal output unit 213 and a bridge circuit 212, logical block 211 is accepted photoelectricity sensing signal 312a and is calculated the amplitude of mems mirror 10 vibrations, and exports the first modulating signal 316a, the second modulating signal 316b and the 3rd modulating signal 316c; Bridge circuit 212 can be accepted the first modulating signal 316a, the second modulating signal 316b and the 3rd modulating signal 316c, produces drive signal 311 with control mems mirror 10; Control signal output unit 213 can be accepted the amplitude difference signal 316d that logical block 211 sends and send stabilization signal 315.In addition, laser controller 23 is the master station of laser printer or multifunctional paper feeding machine, in order to send scan-data 319, whether stablize, whether can send scan-data 319, reach at T in order to differentiate mems mirror 10 to control LASER Light Source 11, to send the startup enable signal 313 that starts mems mirror 10, the adjustment signal 314 that sends adjustment mems mirror 10 ₂(or T ₄) in the time interval with f _DataFrequency is sent scan-data 319.Because T ₂(or T ₄) time and f _DataFrequency can be set by laser printer or multifunctional paper feeding machine, and MEMS laser scanning device only need verify whether the amplitude of mems mirror 10 meets T ₂(or T ₄) time, then can directly be used in laser printer or multifunctional paper feeding machine, avoided complicated control and agreement, this is one of effect of the present utility model.

MEMS scan controller 21 comprises logical block 211, control signal output unit 213 and bridge circuit 212, logical block 211 can be accepted the startup enable signal 313 of laser controller 23, accept the adjustment signal 314 of laser controller 23, accept the amplitude (time of twice triggering photo switches, photo sensors 14a) of photoelectricity sensing signal 312a that photo switches, photo sensors 14a sends to detect mems mirror 10, logical block 211 is sent to control signal output unit 213 with the amplitude difference signal, or changes the first modulating signal 316a, the second modulating signal 316b and the 3rd modulating signal 316c export to bridge circuit 212; Control signal output unit 213 is received the amplitude difference signal 316d of logical block 211 and is converted stabilization signal 315 to and informs that laser controller 23 is stable; Bridge circuit 212 according to the different first modulating signal 316a, the second modulating signal 316b drive signal 311 different with the 3rd modulating signal 316c combination results to control the amplitude of mems mirror 10.The time (period T) of triggering twice of photo switches, photo sensors 14a when mems mirror 10 vibration amplitudes is stable, can transmit scan-datas 319 by laser controller 23, is described as follows:

As shown in Figure 2, mems mirror 10 is with the side-to-side vibrations of Y plane, and its side-to-side vibrations scope is ± θ _cA time t in office, the scanning ray of laser beam 111 incident back reflections and central optical axis (113c) angle theta (t) are for presenting sinusoidal waveform in time, and at the scanning ray of reflection during to photo switches, photo sensors 14a, produce the photoelectricity sensing signal 312a that triggers for the first time, when mems mirror 10 is vibrated to maximum angle θ to the right _cThe time, θ (t) angle maximum; Thereafter, 10 beginnings of mems mirror Hui Zhen, θ (t) angle reduces, the scanning ray of reflection is during to photo switches, photo sensors 14a, produce the photoelectricity sensing signal 312a that triggers for the second time, in scanning ray arrives the effective scanning form (113a to 113b is promptly between a to b of Fig. 2 point), the relation of angle θ this moment (t) and time t is near straight line, and this is the effective scanning form of forward scan; When mems mirror 10 is vibrated to maximum angle-θ left _cThe time, θ (t) angle maximum; Thereafter, 10 beginnings of mems mirror Hui Zhen, θ (t) angle reduces, in scanning ray arrives the effective scanning form (113b to 113a, promptly the b ' of Fig. 2 is between a ' point), this is the effective scanning form of reverse scan, when mems mirror 10 continues vibration to the right, scanning ray produces the photoelectricity sensing signal 312a that triggers for the third time during to photo switches, photo sensors 14a, finishes one-period ± θ _cScanning, when mems mirror 10 to maximum angle θ _cThe time begin Hui Zhen, θ (t) angle reduces, scanning ray produces the photoelectricity sensing signal 312a that triggers for the 4th time during to photo switches, photo sensors 14a.

Because mems mirror 10 is with f ₀Frequency is vibrated back and forth, and vibration time of finishing one-period is T from left to right, is called the scan period, forward scan and reverse scan as shown in Figure 4, in the scan period, when θ (t) reduces in scanning ray 114a position, T promptly delays time ₁Time, angle θ this moment (t) and the pass of time t are near straight line, and laser controller 23 sends scan-data 319, and sending data time is T ₂, this is for the effective scanning form of forward scan; As time-delay T ₃After, laser controller 23 sends scan-data 319, and sending data time is T ₄, this is for the effective scanning form of reverse scan; And T ₁, T ₂, T ₃, T ₄Be in a scan period T, to finish.T ₁, T ₂, T ₃, T ₄Between the relation as follows: work as f ₀During=2500HZ, calculate T by Eq. (1)～Eq. (5) ₁=1.137 * 10 ^-5, T ₂=T ₄=1.2377 * 10 ^-4, T ₃=7.623 * 10 ^-5(second), f _Data=3.7 * 10 ⁷(HZ).

The startup enable signal 313 that sends when laser controller 23 is during for noble potential, it promptly is the startup activation of not sending mems mirror 10, change into electronegative potential by noble potential, it promptly is the startup activation of sending mems mirror 10, as Fig. 5, but it is still unstable after mems mirror 10 startups this moment, laser controller 23 control signal output units 213 sent stabilization signal 315 and were electronegative potential this moment, sending and adjusting signal 314 is electronegative potential, after a period of time, mems mirror 10 is stable, stabilization signal 315 transfers noble potential to, adjust signal 314 and transfer noble potential to, and send the first modulating signal 316a by logical block 211, the second modulating signal 316b and the 3rd modulating signal 316c produce drive signal 311 via bridge circuit 212, and mems mirror 10 is vibrated left; After mems mirror 10 vibrated back and forth, each scan period T can trigger photo switches, photo sensors 14a twice, can be calculated the triggering period T of photoelectricity sensing signal 312a thus by logical block 211.Calculating T ₁, T ₂, T ₃, T ₄The time, the logical block 211 of MEMS scan controller 21 can receive the trigger pip 312a that photo switches, photo sensors 14a produces, and calculates the triggering period T of the trigger pip 312a of each photo switches, photo sensors 14a generation, to adjust the amplitude of mems mirror 10.

As shown in Figure 6, the pulse of the 3rd modulating signal 316c of the first modulating signal 316a, the second modulating signal 316b and amplitude relation is set as follows: in resonance cycle T, the burst length of the first modulating signal 316a and the second modulating signal 316b is TA ₁And TA ₃, and establish TA ₁=TA ₃, the interval is TA between the first modulating signal 316a and the second modulating signal 316b pulse ₂With TA ₄, and establish TA ₂=TA ₄, TA ₁/ TA ₄Can be set at certain value, TA ₁+ TA ₂+ TA ₃+ TA ₄=T promptly finishes the first modulating signal 316a and the second modulating signal 316b respectively once in resonance cycle T, be 1/T, wherein TA even the first modulating signal 316a and second modulating signal 316b driving mems mirror 10 make the resonant frequency of mems mirror 10 ₁/ TA ₄Ratio is not for limiting, and visual control loop and changing uses TA at present embodiment ₁/ TA ₄=1/4; The 3rd modulating signal 316c is for being reduced to the process of electronegative potential by noble potential, the time that noble potential is kept is TA ₁₀, electronegative potential time of keeping is TA ₉, the time T A that noble potential is kept ₁₀With the load D that the ratio of period T (t) is then adjusted for amplitude, set the frequency that the 3rd modulating signal 316c is 1K HZ (frequency is used the frequency of 1K HZ for not limiting at present embodiment), promptly set TA ₁₁=1/1000, D=TA ₁₀/ TA ₁₁, TA ₉+ TA ₁₀=TA ₁₁, can adjust the waveform of the 3rd modulating signal 316c by adjusting D numerical value, by the amplitude of bridge circuit 212 with change mems mirror 10.

The applied control method of the utility model comprises the following step, as Fig. 7:

S21: the initial value of assumed load (present embodiment is set D=90%), setting cycle initial value T (present embodiment setting T=1/f ₀=4.21 * 10 ^-4(sec), laser controller 23 control LASER Light Source 11 are sent laser beam 111;

S22: check that photoelectricity sensing signal 312a is in half period 4.21 * 10 ^-4Whether be triggered twice in the sec;

S23: then the first modulating signal 316a, the second modulating signal 316b and the 3rd modulating signal 316c are made as electronegative potential when adjusting frequency;

S24: whether the triggered time of checking photoelectricity sensing signal 312a is in ± 3%; If the triggered time correctly then be judged as continous-stable, if continous-stable then send stabilization signal 315 by MEMS scan controller 21; If the triggered time surpasses ± 3%, then begin to adjust amplitude;

S25: when adjusting amplitude, adjust load D value, D value is raise or decline,, make that amplitude can trigger secondary photo switches, photo sensors 14a in half period with the change amplitude.

The triggered time mobility scale 3% of photoelectricity sensing signal 312a just is recited in this as an example, but not as limit, it can be set according to user's needs, for example, also can be set to 5%.

After the amplitude of mems mirror 10 was correct, MEMS scan controller 21 sent stabilization signal 315, then can begin to transmit scan-data 319.The method of transmission scan-data as shown in Figure 8, if laser controller 23 sends when starting enable signal 313 or adjusting signal 314, then go out the first modulating signal 316a, the second modulating signal 316b and the 3rd modulating signal 316c and give bridge circuit 212 by logical block 211 calculating and sending, and send drive signal 311 by bridge circuit 212 and adjust, and judge by logical block 211 whether mems mirror 10 is stable, mems mirror 10 started and finished this moment.

After mems mirror 10 was stablized, the logical block 211 of MEMS scan controller 21 was sent signal and is given control signal output unit 213, and 213 of control signal output units send stabilization signal 315; Wherein stabilization signal 315 can with laser controller 23 prearranges, for changing noble potential into, or change electronegative potential into, or the signal of output characteristic frequency by noble potential by electronegative potential.

Laser controller 23 is with predetermined transmission frequency f _DataAnd send forward scan transmission data timing T in photo switches, photo sensors 14a back time-delay T1 time that is triggered ₂Time; After sending the termination of forward scan transmission data, the time-delay T3 time is sent reverse scan transmission data timing T ₄Time.

Thus, the transmission frequency f of laser controller 23 _DataAnd transmission time T ₂With T ₄For setting in advance, 21 control of MEMS scan controller mems mirror 10 is with natural reonant frequency f ₀And control its amplitude and can trigger photo switches, photo sensors 14a, at T ₂Or T ₄Transmit scan-data 319 in time.The purpose of this utility model is to provide a kind of MEMS scan controller 21, makes behind mems mirror 10 stable oscillations, sends stabilization signal 315 by MEMS scan controller 21 and makes MEMS scan controller 21 can use default transmission frequency f _Data, at effective scanning form (T ₂Or T ₄In time) transmission scan-data 319.

As shown in Figure 9, during forward scan, in time scan-data is sent to LASER Light Source 11 at T2 by MEMS scan controller 21 at a～b in time, LASER Light Source 11 is sent laser beam 111 by mems mirror 10 forward scans becoming scanning ray 113a～113b.Each point angular velocity difference between a～b, promptly θ (t) is not though near straight line, be linear relationship; Scan mirror 13 can be linear relationship and imaging on object 15 with scanning ray 113a～113b revisal, to improve the quality of scanning.It act as the linear function eyeglass scan mirror 13, because θ (t) sends two times between luminous point when a point is δ T, the angular velocity of ordering less than center c because of the angular velocity of ordering near a point or b, cause after mems mirror 10 scanning, spot distance δ Za and δ Zb less than the center apart from δ Zc; Scan mirror 13 has optical surface, not equidistant δ Za and δ Zb can be proofreaied and correct, and making the luminous point that is projected on the object 15 is equidistant δ Z, with the distortion of correct scan, obtains high-precision scanning effect.

When being applied to laser printer or multifunctional paper feeding machine, if setting, the scan-data of laser printer or multifunctional paper feeding machine 319 uses 35MHz, and 5102 data are respectively transmitted in forward scan or reverse scan, and then can get the transmission time according to Eq. (5) is T ₂=T ₄=0.1458msec, the laser controller 23 of laser printer or multifunctional paper feeding machine will transmit data in the time at 0.1458msec.If selected frequency is the mems mirror 10 of 2500HZ, calculate θ by Eq. (2) _n=± 20.95 °; For indivedual discrepant natural reonant frequency f ₀=2575～2425Hz is at T ₂=T ₄The scanning angle of=0.1458msec time is θ _n=± 21.26 °～± 20.601 °, i.e. Δ θ _n=0.325 °, when being installed in laser printer or multifunctional paper feeding machine for the indivedual discrepant different mems mirrors 10 of natural reonant frequency, it is 0.325 ° that two paper that two laser printers or multifunctional paper feeding machine are printd have the greatest impact relatively, and print quality is still in tolerance interval.

＜embodiment two 〉

Present embodiment is applied to the MEMS laser scanning device of two photo switches, photo sensors; As shown in Figure 1, other is provided with photo switches, photo sensors 14b in θ _p=-21 °.Present embodiment still uses natural reonant frequency f ₀=2500 ± 3%HZ, maximum scan angle are ± 23 ° mems mirror 10.MEMS scan controller 21 accept laser controller 23 startup enable signal 313, accept laser controller 23 adjustment signal 314, accept photoelectricity sensing signal 312a that photo switches, photo sensors 14a sends and accept the photoelectricity sensing signal 312b that photo switches, photo sensors 14b sends, with the amplitude of detecting mems mirror 10, and produce drive signal 311 with control mems mirror 10.

As shown in Figure 3, MEMS scan controller 21 comprises logical block 211, control signal output unit 213 and bridge circuit 212, logical block 211 can be accepted the startup enable signal 313 of laser controller 23, accept the adjustment signal 314 of laser controller 23, accept the photoelectricity sensing signal 312b that photo switches, photo sensors 14b sends, accept the photoelectricity sensing signal 312a that photo switches, photo sensors 14a sends, amplitude (secondary triggers the time of photo switches, photo sensors 14a) with detecting mems mirror 10, logical block 211 is sent to control signal output unit 213 with the amplitude difference signal, or changes the first modulating signal 316a, the second modulating signal 316b and the 3rd modulating signal 316c output give bridge circuit 212; Control signal output unit 213 converts the amplitude difference signal 316d of the logical block 211 received to stabilization signal 315 and informs that laser controller 23 is stable; Bridge circuit 212 according to the different first modulating signal 316a, the second modulating signal 316b drive signal 311 different with the 3rd modulating signal 316c combination results to control the amplitude of mems mirror 10.The time (period T) of promptly triggering photo switches, photo sensors 14a, photo switches, photo sensors 14b secondary when mems mirror 10 vibration amplitudes is stable, can transmit data scanning by laser controller 23, is described as follows:

Mems mirror 10 is with the side-to-side vibrations of Y plane, and its side-to-side vibrations is ± θ _cA time t in office, the scanning ray of laser beam 111 incident back reflections and central optical axis (113c) angle theta (t) are for presenting sinusoidal waveform in time, and in the scanning ray of reflection during to photo switches, photo sensors 14a, produce the photoelectricity sensing signal 312a that triggers for the first time, when mems mirror 10 is vibrated to maximum angle θ to the right _cThe time, θ (t) angle maximum; Thereafter, 10 beginnings of mems mirror Hui Zhen, θ (t) angle reduces, the scanning ray of reflection is during to photo switches, photo sensors 14a, produce the photoelectricity sensing signal 312a that triggers for the second time, in scanning ray arrives the effective scanning form (113a to 113b is promptly between a to b of Fig. 2 point), the relation of angle θ this moment (t) and time t is near straight line, and this is the effective scanning form of forward scan; When mems mirror 10 is vibrated to maximum angle-θ left _cThe time, θ (t) angle maximum; Thereafter, 10 beginnings of mems mirror Hui Zhen, θ (t) angle reduces, in scanning ray arrives the effective scanning form (113b to 113a, promptly the b ' of Fig. 2 is between a ' point), this is the effective scanning form of reverse scan, when mems mirror 10 continues vibration to the right, scanning ray produces the photoelectricity sensing signal 312a that triggers for the third time during to photo switches, photo sensors 14a, finishes one-period ± θ _cScanning, when mems mirror 10 to maximum angle θ _cThe time begin Hui Zhen, θ (t) angle reduces, scanning ray produces the photoelectricity sensing signal 312a that triggers for the 4th time during to photo switches, photo sensors 14a; When scanning ray was finished one-period, scanning ray can scan each secondary of photo switches, photo sensors 14a, 14b totally four times, can produce twice of the photoelectricity sensing signal 312b of triggering, the photoelectricity sensing signal 312b that produce to trigger twice.

After mems mirror 10 vibrates back and forth, each scan period T/2 scanning ray 114a can trigger secondary photo switches, photo sensors 14a, and scanning ray 114b can trigger secondary photo switches, photo sensors 14b, can calculate the triggering period T of photoelectricity sensing signal 312a and 312b thus by logical block 211, and the time of calculating the trigger pip 312a and the trigger pip 312b that photo switches, photo sensors 14b produces of each photo switches, photo sensors 14a generation, and the first modulating signal 316a of generation mems mirror 10, the second modulating signal 316b and the 3rd modulating signal 316c accept first by bridge circuit 212, second, the 3rd modulating signal also produces drive signal 311 in order to adjust the amplitude of mems mirror 10.

Behind mems mirror 10 reflector laser light 111, the time of vibrating to the right and triggering the time of photo switches, photo sensors 14a secondary and trigger photo switches, photo sensors 14b secondary by the left side, as shown in figure 11, adjacent secondary triggers the time of photo switches, photo sensors, and promptly triggering for the second time photo switches, photo sensors 14a is TA with the time interval of triggering photo switches, photo sensors 14b for the first time ₆, TA when mems mirror 10 is stablized ₆Also stable.The method of the amplitude of MEMS scan controller 21 control mems mirrors 10 is with first embodiment, as shown in figure 11.In the present embodiment, photo switches, photo sensors 14a and photo switches, photo sensors 14b are installed in θ _p=± 21 °, promptly when f=2500HZ,, can calculate TA by Eq. (6) ₆=1.4651 x 10 ^-4Sec., present embodiment is then with TA ₆=1.5090-1.4211 x 10 ^-4Sec. be whether stable judgement.

＜embodiment three 〉

Present embodiment is applied to a photo switches, photo sensors and MEMS laser scanning device that scan mirror is made of two eyeglasses; When pinpoint accuracy demand more, when having required minimum difference, scan mirror 13 can be made as by first scan mirror 131 and second scan mirror 132 and be constituted for the paper of prining of different two laser printers or multifunctional paper feeding machine.As shown in figure 12, first scan mirror 131 is the angularity correction eyeglass, by with the distance of second scan mirror 132, the scanning ray 113a-113b that is incident in first scan mirror 131 is adjusted into and is incident to second scan mirror 132 for identical, become linearization through the linear function eyeglass revisal of second scan mirror 132.Shown in Figure 13,14, with first embodiment, for natural reonant frequency f ₀The mems mirror 10 of=2500HZ is at laser printer or the default data transmitted frequency of multifunctional paper feeding machine f _Data=35MHZ and default delivery time T ₂=T ₄Under=the 0.1458msec, for natural reonant frequency f ₀The mems mirror 10 of=2500HZ, its scanning form is 2 θ _n=2*20.947 °, first scan mirror, 131 central points and the distance of second scan mirror, 132 central points on central optical axis are d ₀=12.5mm, imaging length is L on object 15 ₀, this L usually ₀Length is 95% of A4 size paper width 216mm.For the mems mirror 10 that different MEMS laser scanning devices is installed, its natural reonant frequency f0 has other difference (as ± 3%), and produces Δ θ in the scanning form _nIt is L that=0.325 difference, this difference will make imaging length ₀± 1.6mm.For proofreading and correct this difference, can resonant frequency f will be operated in ₀First scan mirror 131 of the mems mirror 10 of=2425HZ and second scan mirror, 132 distances are adjusted into d ₀-Δ d, present embodiment cooperate first scan mirror 131 and 132 designs of second scan mirror, and first scan mirror, 131 central points and the distance of second scan mirror, 132 central points on central optical axis are d ₀-Δ d=12.364 (mm); In like manner, resonant frequency f ₀First scan mirror, 131 central points of the mems mirror 10 of=2575HZ and the distance of second scan mirror, 132 central points on central optical axis are d ₀+ Δ d=12.636 (mm); The difference that causes different imaging length because of mems mirror 10 differences of different natural reonant frequencies can be eliminated like this, effect can be obtained to scan more accurately.

For the MEMS laser scanning device of two photo switches, photo sensors, the method that then can use present embodiment to set forth is contrasted equally and is calculated and adjust.

＜embodiment four〉control 1 with the agreement of laser controller

Because MEMS scan controller 21 can make mems mirror 10 reach stable oscillation under the predetermined angle in its natural reonant frequency; Wherein, MEMS scan controller 21 further comprises logical block 211, control signal output unit 213 and bridge circuit 212, wherein, logical block 211 can receive the photoelectricity sensing signal 312a that photo switches, photo sensors 14a produces, calculate the frequency and the amplitude of mems mirror 10 vibrations by logical block 211, and, make mems mirror 10 be vibrated to peak swing and stable by the control of logical block 211 with bridge circuit 212.After mems mirror 10 is vibrated to peak swing and stablizes, send signal by logical block 211 and give control signal output unit 213,213 of signal output units send stabilization signal 315 and give laser controller 23.

In the present embodiment, as shown in figure 10, after mems mirror 10 is stablized, the control signal output unit 213 of MEMS scan controller 21 can further send trigger pip 317 and give laser controller 23, this trigger pip 317 is a prearrange, when laser controller 23 receives 317 beginnings of trigger pip or stops to transmit scan-data 319.In the present embodiment, trigger pip 317 is transformed into noble potential at a of Fig. 2 point (or b ' point) by electronegative potential, when laser controller 23 is received stabilization signal 315 and trigger pip 317 for noble potential, promptly begins to transmit scan-data 319; The b point (or a ' point) that is vibrated to Fig. 2 when mems mirror 10 then trigger pip 317 is transformed into electronegative potential by noble potential, when laser controller 23 is received stabilization signal 315 and trigger pip 317 for electronegative potential, promptly stops to transmit scan-data 319; The transmission of scan-data 319 that so can simple and easy control laser controller 23.

＜embodiment five〉control 2 with the agreement of laser controller

After mems mirror 10 began vibration, logical block 211 can receive the photoelectricity sensing sensing signal 312a that photo switches, photo sensors 14a produces, and calculated the frequency and the amplitude of mems mirror 10 vibrations by logical block 211.In the present embodiment, logical block 211 can further be compared the vibration frequency of mems mirror 10 and scan-data 319 frequency f of laser controller 23 _DataWhether mate, if both frequencies can't cooperate (f _DataDeparted from former setting value), then logical block 211 can further be sent frequency errors signal 318, and as shown in figure 10, laser controller 23 receives 318 of these frequency errors signals and carries out sweep frequency f by laser controller _DataAdjustment.By this sweep frequency f _DataAdjustment, can make scan-data 319 in scanning form in correct transmission.

More than only be illustrative and nonrestrictive to the description of utility model; those skilled in the art is understood; within spirit that following appended claim limits and scope, can make many modifications, change or equivalent, but they all will fall in the protection domain of the present utility model it.

Claims (8)

1, a kind of MEMS scan controller of inherence frequency, it is applied to laser scanning device, this laser scanning device comprises: a LASER Light Source its in order to produce laser beam; One mems mirror it utilize resonance mode driving catoptron with forward scan and reverse scan laser beam to be scanned on object; It receives one photo switches, photo sensors scanning ray and light signal is transformed into the photoelectricity sensing signal; It is transformed into the one scan eyeglass scanning ray and makes its angle and time linear; And a laser controller its control described LASER Light Source with frequency preset and time interval and send laser beam; It is characterized in that: described MEMS scan controller is a vibration amplitude of adjusting mems mirror with the natural reonant frequency of mems mirror, and it comprises a logical block, a control signal output unit, reaches a bridge circuit, wherein:

Described logical block receives the photoelectricity sensing signal that described photo switches, photo sensors produces, and the interval time of calculating each photoelectricity sensing signal, gives described bridge circuit with the modulating signal that produces described mems mirror; And the amplitude difference signal that produces described mems mirror gives described control signal output unit;

Described control signal output unit receives the amplitude difference signal of described logical block and converts it to the stabilization signal of the described laser controller of control;

Described bridge circuit receives the modulating signal of described logical block and to the drive signal of converting to drive the vibration of described mems mirror;

By this, laser scanning device is sent scan-data according to frequency preset and time interval in the effective scanning form.

2, the MEMS scan controller of inherence frequency according to claim 1, it is characterized in that: the scan mirror of this laser scanning device is made up of one first scan mirror and one second scan mirror, wherein, cause when influencing the effective scanning form when the natural reonant frequency of the employed mems mirror of described laser scanning device is variant, by adjusting described first scan mirror and the relative distance of described second scan mirror on optical axis with by way of compensation.

3, the MEMS scan controller of inherence frequency according to claim 1, it is characterized in that: this control signal output unit receives the stable signal of mems mirror of described logical block, and further export trigger pip, in the scanning form, begin or stop to transmit scan-data in order to control described laser controller.

4, the MEMS scan controller of inherence frequency according to claim 1, it is characterized in that: this logical block is compared the vibration frequency of described mems mirror and the predetermined scan-data frequency of described laser controller, and during greater than preset range, further send the frequency errors signal and give described laser controller by described logical block in the two difference.

5, a kind of MEMS scan controller of inherence frequency, it is applied to laser scanning device, this laser scanning device comprise a LASER Light Source its in order to produce laser beam; One mems mirror it utilize resonance mode driving catoptron with forward scan and reverse scan laser beam to be scanned on object; Two photo switches, photo sensors, it receives scanning ray and light signal is transformed into the photoelectricity sensing signal; It is transformed into the one scan eyeglass scanning ray and makes its angle and time linear; And a laser controller its control described LASER Light Source with frequency preset and time interval and send laser beam; It is characterized in that: described MEMS scan controller is a vibration amplitude of also stablizing mems mirror in order to the natural reonant frequency of detecting mems mirror, and it comprises a logical block, a control signal output unit, reaches a bridge circuit, wherein:

Described logical block receives the photoelectricity sensing signal that described two photo switches, photo sensors produce, and calculates the interval between each photoelectricity sensing signal, gives described bridge circuit with the modulating signal that produces described mems mirror; And produce the stable signal of described mems mirror and give described control signal output unit;

Described control signal output unit receives the stable signal of the mems mirror of described logical block and converts it to the stabilization signal of the described laser controller of control;

Described bridge circuit receives the modulating signal of described logical block, to the drive signal of converting to drive the vibration of described mems mirror;

By this, laser scanning device is sent scan-data according to frequency preset and time interval in the effective scanning form.

6, the MEMS scan controller of inherence frequency according to claim 5, it is characterized in that: the scan mirror of described laser scanning device is made up of first scan mirror and second scan mirror, wherein, cause when influencing the effective scanning form when the natural reonant frequency of the employed mems mirror of described laser scanning device is variant, by adjusting described first scan mirror and the relative distance of described second scan mirror on optical axis with by way of compensation.

7, the MEMS scan controller of inherence frequency according to claim 5, it is characterized in that: this control signal output unit receives the stable signal of mems mirror of described logical block, and further export trigger pip, in the scanning form, begin or stop to transmit scan-data in order to control described laser controller.

8, the MEMS scan controller of inherence frequency according to claim 5, it is characterized in that: this logical block is compared the predetermined scan-data frequency of described mems mirror vibration frequency and described laser controller, and further during greater than preset range, send the frequency errors signal by described logical block and give described laser controller in the two difference.

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