JP2005173159A - Micromirror scanner and method of controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constitution with which electrostatic force is surely controlled and a necessary operation is performed efficiently, when scanning operation is performed by controlling rocking of a micromirror for performing various scanning operations, by constituting an image plotting apparatus using an electrostatically driven type micromirror scanner. <P>SOLUTION: The rocking velocity and the rocking pattern of the mirror are easily set, and such rocking motions as stop, acceleration, and direction change can be controlled, by applying an electric voltage waveform deformed into a required pattern according to an aimed rocking operation, when a voltage is applied between electrodes for an electrostatic driving. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrostatic drive type micromirror scanner that can constitute a suitable image drawing apparatus for use in a laser beam printer, a copying machine, etc. The present invention relates to a micromirror scanner for controlling motion accurately and efficiently and a control method thereof.

In recent years, micro-machining technology such as etching or film formation is used on a semiconductor substrate such as silicon, and for example, a micro-mirror that is configured by forming a required groove is supported by a suspension beam so that it can be swung. Various electrostatically driven micromirror scanners have been proposed in which an electrostatic force is generated by an electrode pair provided to swing the mirror.
JP 2002-311376 (US 2002/0158548 A1, Fig. 12A) JP2003-248183 JP2003-015064 US 6,643,052 B2 (Figure 12B, C)

  The micromirror scanner is driven by an electrostatic force, and can change the reflection path of incident light according to the rotation angle about the suspension beam, and can perform switching and scanning of laser light.

Conventional image drawing devices used in laser beam printers, copiers, etc. reflect incident laser light with a polygon mirror (30) or a galvanometer mirror to scan at a high speed, and a predetermined image on a rotating drum (31). Is configured to draw. (See Figure 4A)
JP 5-119279 A

  In order to increase the rotation angle of the micromirror, according to the invention of Japanese Patent Laid-Open No. 2002-311376, if the vibrating body is operated at a frequency that matches the resonance frequency of the vibrating body, the vibrating body can be efficiently used even with a small driving force due to the resonance phenomenon. The resonance frequency control electrode and the amplitude control electrode are independently operated to control both the resonance frequency and the amplitude of the micromirror, and the spring of the rotation shaft of the micromirror. A configuration is proposed in which a large rotation angle can be obtained with a small driving force by reducing the constant.

  2. Description of the Related Art Image drawing apparatuses used in laser beam printers, copiers, and the like are required to perform high-speed scanning of a micromirror scanner, which is a scanner engine, and to reliably control various operations because of demands for higher-speed and multi-functional printers.

  However, the conventional devices and control methods only propose a configuration and control mainly for the purpose of increasing the mirror amplitude. For example, in a configuration and control method that can surely realize a scanning operation for practical use, There wasn't.

  In the present invention, when an image drawing apparatus is configured using an electrostatic drive type micro mirror scanner, it is assumed that various scanning operations are performed, and when the scanning operation is performed by controlling the swing of the micro mirror. An object of the present invention is to provide a micromirror scanner having a configuration capable of reliably controlling the electrostatic force and efficiently performing a required operation, and a method for controlling the micromirror scanner.

  As a result of intensive studies on electrostatic driving methods that can perform various scanning operations reliably and efficiently when an image drawing apparatus is configured using an electrostatically driven micromirror scanner, When a voltage is applied between the electrodes, the mirror swing speed and swing pattern can be easily set by applying a voltage waveform deformed into the required pattern according to the desired swing operation. It has been found that it is possible to control rocking motion such as stopping, accelerating and changing direction.

  In addition, as a result of diligent investigations on countermeasures for fluctuations and fluctuations in the swinging motion of the micromirror due to temperature fluctuations of the device itself in the electrostatically driven micromirror scanner, the inventors have transformed into the required pattern. By applying a specific voltage waveform set to correct the oscillation operation according to the temperature fluctuation of the device itself to the voltage waveform for the previous drive, The present invention was completed by discovering that temperature correction can be realized.

  That is, according to the present invention, an electrostatically driven micromirror scanner in which a mirror that is supported by a suspension beam so as to be swingable is formed on a semiconductor substrate. When applying a voltage, the voltage waveform to be applied is transformed into a required pattern or a required pattern is selected and applied, and if necessary, the oscillation motion is corrected according to the device temperature or a temperature in the vicinity thereof. A method for controlling a micromirror scanner, further comprising applying a voltage waveform of a required pattern for controlling a swinging motion of the mirror, such as a swinging speed, a swinging pattern, stop, acceleration, and direction change. .

  The present invention also provides an electrostatically driven micromirror scanner in which a mirror is supported on a semiconductor substrate so as to be swingable by a suspension beam by a micromachining technique for film formation and / or etching, and for swinging the mirror. A micromirror scanner comprising: means for applying a voltage waveform deformed into a required pattern or means for selecting and applying a voltage waveform deformed into a required pattern between electrodes for electrostatic driving.

  Furthermore, the present invention can also employ a method of controlling the oscillation operation by taking out and monitoring a part of the laser light incident or reflected on the micromirror in the micromirror scanner having the above configuration or the control method thereof, Use multiple lasers or combined lasers of different wavelengths for incoming and reflected laser light, or use a diffraction grating in the reflected light path to reflect or emit multiple lasers, or to enter incoming laser light It is possible to use a method in which a mirror position detection light beam is input and the position detection light beam is separately detected.

In the above-described micromirror scanner of the present invention,
A configuration in which a micromirror and a suspension beam are formed by a groove provided on a substrate, and an electrode for electrostatic driving is disposed in the groove.
A micromirror and a suspension beam are formed by grooves provided on the substrate, and a second suspension beam is formed by arranging a groove on the outer periphery of the micromirror and the suspension beam, and an electrostatic drive electrode is provided in each groove. A configuration in which the micromirror has two different electrostatic drive sources in two axes, coaxial or orthogonal,
A configuration in which an electrostatic drive electrode disposed in the groove is disposed along the suspension beam;
A configuration in which another substrate is laminated on a substrate provided with a micromirror, and a planar electrode is disposed opposite to the non-reflecting surface of the mirror,
A configuration in which micromirrors, suspension beams, grooves, and electrodes for electrostatic driving are formed by micromachining technology of film formation and / or etching,
Each of these can be used alone or in combination.

  In the present invention, as shown in the examples, the micromirror scanner itself is a very small mirror having a mirror size of 4 mm square or less, preferably 2 mm or less in a preferred embodiment, and is a conventional polygon mirror used for performing a scanning operation (FIG. 4A). Compared with the driving of the reference), the mirror itself and the light reflecting surface do not change in position, and have the inherent characteristics that miniaturization, noise reduction, power saving, and long life can be achieved. In particular, the control method according to the present invention exhibits a driving force using a voltage waveform transformed into a required pattern, so that the micromirror scanner having any configuration can be used without excluding the basic functions of the scanner itself. The target operation can be executed.

  The control method according to the present invention can swing the micromirror scanner at several kHz, and can perform high-speed scanning equivalent to or higher than that of a conventional polygon mirror scanner, increase the scan effective time, and scan speed. Can be controlled at a constant level, and variations in scan frequency can be reduced, thereby realizing a stable scanning operation. Also, when scanning the micromirror scanner, for example, the speed difference on the outer peripheral surface of the cylindrical drum can be reduced, the maximum deflection angle of the mirror can be set relatively small, and excessive specifications are required for the device itself. There is nothing and it is excellent in practical use.

  The control method according to the present invention uses a configuration of a micro mirror scanner in which a micro mirror is coaxial and has two different electrostatic drive sources, and adds a speed correction by a sub drive swing pattern to a scanning speed by a main drive swing pattern. Thus, the speed can be adjusted and the scanning speed can be made constant. In addition, in the configuration in which the micromirror 3 has two different electrostatic drive sources with two orthogonal axes, reciprocating scanning and two-dimensional plotter operation are possible.

  In this invention, an electrostatically driven micromirror scanner in which a mirror supported on a target semiconductor substrate by a suspension beam is formed is manufactured by patterning and laminating thin films of various materials on the substrate. Manufactured by surface micromachining, or bulk micromachining such as etching the substrate itself or further performing film formation.

  The suspension beam structure that supports the micromirror in a swingable manner is formed by opposing the U-shaped groove, which is a conventional configuration, to form a single beam at the center of the micromirror, and the suspension Various configurations such as multiple beams and V, M-shape can be adopted.

  In addition, the electrostatic drive type micro mirror scanner can employ a planar electrode configuration or a comb electrode configuration shown in FIGS. 12A and 12B as a capacitive element of the drive source.

  The planar electrode configuration can be formed by appropriately arranging the counter electrode between the movable side of the substrate on which the micromirror is formed and the fixed side substrate to be laminated or between the films. The comb-shaped electrode configuration employs a configuration in which a large number of comb teeth are formed between the movable and fixed sides of the substrate on which the mirror is formed, and a large number of capacitors are arranged by arranging electrodes between the opposing comb-tooth surfaces. Is possible.

  For example, as shown in FIG. 1, the electrostatically driven micromirror scanner 1 according to the present invention is provided with U-shaped grooves 4 and 4 opposed to the central portion of the semiconductor substrate 2, and is surrounded by the grooves 4 and 4. The mirror 3 is configured to be swingably supported by suspension beams 5 and 5 in a substantially vertical (y) direction in the figure.

  In the configuration of FIG. 1, the driving electrode of the micromirror 3 is formed in the U-shaped grooves 4 and 4, but here the micromirror 3 side and the substrate 2 side are etched when the substrate 2 is etched. Comb-shaped electrodes 10 and 11 arranged alternately are formed.

  In addition, in the configuration of the electrode for electrostatic driving in which the comb-shaped electrodes are arranged in the grooves 4 and 4, it is possible to arrange different electrode groups in the same comb teeth in a required pattern, and different voltages Waveforms can be applied.

  Furthermore, as shown in FIG. 1, it can be combined with a planar electrode configuration. That is, when the other substrate 21 is laminated on the substrate 2 of the micromirror 3, the planar electrode is formed on the non-reflecting surface side of the micromirror 3, and the planar electrodes 22 and 22 are formed on the central portion of the other substrate 21. In addition, an electrostatic element can be formed by arranging and laminating spacers on the outer peripheral portion of the substrate 21. For example, a required DC voltage waveform can be applied. Alternatively, the electrostatic element may be formed by forming a concave portion in the central portion of another substrate 21 and forming a planar electrode there.

  As the electrostatic drive type micromirror scanner 1 according to the present invention, the configuration example shown in FIG. 2 is a configuration in which the micromirror 3 has two different electrostatic drive sources with two orthogonal axes, and is U-shaped facing the center of the substrate 2. In addition to the configuration in which the grooves 4 and 4 of the mold are provided so that the micromirror 3 is swingably supported by suspension beams 5 and 5 in a substantially vertical (y) direction in the figure, the micromirror 3 and the suspension beams 5 and 5 are surrounded. In order to form a frame 7, U-shaped grooves 6 and 6 are provided, and the suspension mirrors 8 and 8 in the left and right (x) directions in the figure are used to make the micromirror 3 itself orthogonal to the swing axis. It is configured to be tilted in the direction or supported so as to be swingable.

  Electrodes for electrostatic driving have comb-shaped electrodes 10 and 11 formed in the above-mentioned U-shaped grooves 4 and 4 in the same manner as the configuration of FIG. In order to incline or swing the entire frame 7 surrounding 5, comb-shaped electrodes 12 and 13 arranged alternately on the frame 7 side and the substrate 2 side are formed in U-shaped grooves 6 and 6. It is.

  In addition, the configuration example of the micromirror scanner 1 shown in FIG. 3 is basically the same configuration as FIG. 2 described above, but the micromirror 3 is coaxial and has two different electrostatic drive sources. 3 and the positions of the suspension beams 9 and 9 of the frame 7 surrounding the suspension beams 5 and 5 are provided so as to be coaxial with the substantially vertical (y) direction of the suspension beams 5 and 5 of the micromirror 3.

  As described above, in the electrostatic drive type micro mirror scanner 1 in which the mirror 3 supported so as to be swingable by the suspension beams 5 and 5 is formed on the semiconductor substrate 2, the comb-shaped electrodes 10 and 11 for electrostatic drive are In order to apply a DC voltage so as to match or approximate the resonance frequency of the micromirror, the DC voltage value is obtained in advance and set in the voltage control means, and then the drive for driving the mirror 3 to oscillate An AC voltage is applied between the electrodes 10 and 11. When a planar electrode is used in the configuration of FIG. 1, a required DC voltage waveform can be applied to the planar electrodes 22 and 22.

  Depending on the configuration of the suspension beam, the specific resonance frequency of the micromirror is determined. Furthermore, the spring constant of the rotation axis of the micromirror, the expected swinging pattern of the mirror, the required mirror amplitude, that is, the rotation angle, etc. The DC voltage value may be determined in consideration of how much resonance should occur, whether the deflection angle should be maximized, or within a certain range.

  Further, it is possible to apply the bias voltage by changing the bias voltage constant or as necessary, or to use a means for changing the spring constant of the rotating shaft of the micromirror as necessary.

  In the present invention, when applying the oscillation drive AC voltage, the voltage waveform to be applied is transformed into a required pattern according to the voltage control means, or the voltage waveform is applied in advance to a plurality of required patterns. By setting the voltage waveform pattern so that it can be applied with a switch, or by selecting or applying any voltage waveform pattern with a switch or signal, the micromirror's rocking speed, rocking pattern, or stop, acceleration, direction Oscillating motion such as conversion can be appropriately controlled.

  As shown in FIG. 4B, in order to scan a linear plane of the outer periphery of the drum 31 having a required width or a linear plane having a required width, the mirror 33 is oscillated by allowing laser light to enter the micromirror 33 from a certain direction. It is assumed that a scanning operation is performed on a straight plane.

  When the oscillating scanning operation of the micromirror is in one direction as shown in FIG. 4B, since the scan and return are repeated, the voltage waveform during driving is assumed to be a rectangular wave (or a sine wave). As shown in FIG. 5A, by increasing the return voltage, that is, by making the voltage waveform an asymmetric waveform on the horizontal axis of potential 0, the scan effective time can be increased.

  In addition, as shown in Fig.5B, the voltage waveform is stepped as shown in Fig. 5B, in order to shorten the acceleration time by oscillating scanning operation of the micro mirror in one direction and increasing the reverse voltage after the effective scan is completed to brake. A rectangular wave (same as a sine wave) can be applied, and after the effective scan is completed, the return voltage is increased to stop, change the direction, and reaccelerate.

  Further, for the purpose of keeping the scanning speed constant in the unidirectional scanning operation of the micromirror, a rectangular wave having a pulsed voltage waveform can be applied as shown in FIGS. 5C and 5D. In other words, by applying the voltage of the pattern shown in the drawing, the voltage at the intermediate portion of the effective scan can be lowered to lower the scan speed, and control to keep the scan speed constant can be performed.

  The above-described setting and changing of the resonance frequency of the micromirror and the spring constant of the suspension beam can be set in advance and based on literal bias constant control. After securing the basic micromirror swinging operation, the target micromirror is applied by applying the voltage of the required waveform according to the purpose of increasing the scan effective time mentioned above or keeping the scan speed constant. Scanning operation can be ensured.

  In addition, when a temperature change of the device itself occurs during the scanning operation, it is assumed that the basic micromirror swinging operation fluctuates, and the bias voltage control is changed according to the temperature change. be able to. Furthermore, it is possible to employ a control in which the voltage waveform for temperature correction is further superimposed and applied in addition to the voltage waveform for each function and purpose in the driving voltage control while maintaining the constant bias control. . An example of a voltage waveform with simple temperature correction is shown in FIG. 5E.

  In the method for controlling the micromirror scanner according to the present invention, a method of controlling the swinging operation by taking out and monitoring a part of the laser light incident or reflected on the micromirror can be used in combination.

  For example, as shown in FIG. 6, by adopting a half mirror configuration for the micro mirror 33 and monitoring the light receiving element 34 at the same time as writing the laser beam, the exposure is made uniform and the gradation accuracy is improved. Can do. In addition, in the case of multi-gradation, the laser light is stopped when the predetermined exposure amount is reached, or the same image is obtained at the same time as another micromirror is provided on the illustrated light receiving element 34. It is possible to add a new configuration such as improving the function of the system.

  In the control method of the micromirror scanner according to the present invention, a control method using a plurality of laser beams as the laser light incident on and reflected from the micromirror can be employed.

  That is, as shown in FIG. 7A, a large number of scan trajectories can be obtained by making the laser beams a, b, and c enter the micromirror 33 and partially performing scanning operations, and the scans are made parallel to each other. Enables reciprocal scanning operation. In addition, as shown in FIG. 7B, the a and b laser beams can be incident on the micromirror 33 to obtain a and b scanning trajectories repeatedly. This makes it possible to realize a tandem color copier.

  Further, in the control method of the micro mirror scanner according to the present invention, a combined light laser of different wavelengths is used as the incoming laser light, and a diffraction grating is used for the mirror or a diffraction grating is used for the reflection light path, A configuration that reflects and emits a laser can be employed.

  For example, as shown in FIG. 8, the scanning operation of the micromirror scanner can be speeded up by synthesizing laser beams having different wavelengths coaxially and separating them into multiple lasers for each wavelength by the micromirror 33 having a diffraction grating configuration. It is possible to handle a plurality of laser beams at the same time, and colorization is facilitated.

  Further, in the control method of the micromirror scanner according to the present invention, as shown in FIG. 9, a position detection light beam 35 for detecting the position of the micromirror 33 is input to the incident laser light, and the position detection light beam 35 is input to the line sensor. By separately configuring the position detector 36 to detect the angle of the mirror during the scanning operation, for example, the writing accuracy can be greatly improved.

  In order to control the scanning operation speed in the control method of the micro mirror scanner, in addition to applying the required pattern voltage waveform described above, the micro mirror scanner in FIG. 3 is coaxial and has two different electrostatic drive sources. In addition, the comb-shaped electrodes 12 and 10 on the frame 7 side are further fixed so that the voltage waveform of the required pattern is applied to the comb-shaped electrodes 10 and 11 and the speed of the micromirror 3 that swings is constant. It is possible to adjust the speed of the entire frame 7 including the micromirror 3 by applying a voltage waveform of a required pattern to 13.

  In addition, in the configuration in which the micromirror 3 in FIG. 2 has two different electrostatic drive sources with two orthogonal axes, reciprocal scanning is possible. That is, as shown in the operation concept in FIG. 10A, the speed of the micromirror 33 that swings about the y-axis when the voltage waveform of the required pattern is applied to the comb-shaped electrodes (10, 11) is on the frame (7) side. By applying a voltage waveform of the required pattern to the comb-shaped electrodes (12, 13), it is possible to correct the rocking speed of the entire x-axis center of the frame (7) including the micromirror 33, and the scan locus on the photoconductor The trajectory due to the oscillation of the y-axis center before correction of the broken line is added with the correction of the oscillation of the x-axis center to become a trajectory like a solid line, enabling reciprocal scanning.

  Furthermore, the configuration of the micromirror scanner in FIG. 2 enables writing in two dimensions. That is, as shown in the operation concept in FIG. 10A, the micromirror 33 that swings around the y-axis center when the voltage waveform of the required pattern is applied is further applied to the entire frame including the micromirror 33 by applying the voltage waveform of the required pattern. By obtaining rocking about the x-axis center, the planar photoconductor 37 is written in two dimensions and functions as a plotter. Therefore, if the planar photoconductor 37 has a configuration in which, for example, a fluorescent paint is applied, it can function as a display.

  According to the micromirror scanner control method of the present invention, since the electrostatic drive type micromirror scanner is electrostatically driven by applying a voltage waveform having a predetermined pattern set in advance, various swinging motions can be controlled accurately and efficiently. Therefore, a suitable image drawing apparatus can be configured for use in laser beam printers, copiers, and the like. For example, by incorporating a micromirror scanner into various scanner drivers or a printer driver and implementing the control method of the micromirror scanner of the present invention, it is possible to achieve high speed, multiple functions, and high performance.

  In the micromirror scanner of the present invention, as means for applying a voltage waveform deformed into a required pattern between the electrodes for electrostatic drive for swinging the mirror, an oscillator, a CPU, a switching element, a power transistor, etc. In combination, the CPU can be controlled to generate and apply a desired voltage waveform. Further, it is possible to apply a voltage waveform transformed into a required pattern even if a voltage driven amplifier, a current driven amplifier, a transformer or the like is used.

  In addition, using a device with the same configuration, the CPU is preprogrammed so that it can generate voltage waveforms deformed into various patterns, and can be selected arbitrarily or automatically selected under the required conditions In this way, it can be configured to apply various patterns of voltage waveforms.

Example 1
In the configuration of the micromirror scanner shown in Fig. 1, it is an engine for a laser printer that uses infrared laser light and scans a mirror size of 4mm diameter, A4 vertical size 600dpi, dot pitch 42.3μm, total number of dots 7014 Was assumed.

  In order to scan the axial straight line of the outer peripheral surface of the rotating drum, the scanning speed is usually not constant and correction by an fQ lens is required. That is, when the laser scanning speed by the rotating polygon mirror in FIG. 4A was measured, it was found that the end side was fast at the center and the end (30 °) on the rotating drum, and the speed difference was about 30%.

  In the case of the micromirror of the present invention, the laser scan speed in FIG. 11A is represented by a speed difference represented by a white circle in the graph of the relationship between the speed difference with respect to the center of the rotating drum (angle 0) and the angle (laser position φ). Had. When driving this micro mirror scanner, when an fQ lens was used to correct the laser scan speed, the deflection angle was 40-60 °, the reflectance was 90% or more, and the operating frequency was 2.9 kHz.

  Next, in order to keep the scanning speed of the required range on the rotating drum as constant as possible, the driving voltage waveform is reduced so as to reduce the scanning speed at the center of the rotating drum or increase the speed at the end. The deformation was applied. As a result, the speed difference can be greatly reduced as shown by the black circle in the relationship between the speed difference with respect to the center of the rotating drum (angle 0) and the laser position in FIG. 11A, and the scanning can be performed without using the fQ lens. It was possible to expand. In this case, the operating frequency was 2.9 kHz.

Example 2
In Example 1, scanning was performed under the same conditions except that the mirror size was 4.5 mm × 1.2 mm, and an operating frequency of 4 kHz was obtained.

  In addition, assuming that the ambient temperature at which the micromirror scanner operates changes, when the temperature is varied from -10 ° C to 60 ° C, the resonance frequency tends to decrease with increasing temperature as shown by the solid line in Fig. 11B. I found out.

  Therefore, a correction voltage waveform is obtained in advance from the correlation between the resonance frequency and the temperature change, and a voltage waveform for performing temperature correction according to the measured ambient temperature is superimposed on the driving voltage waveform of the micromirror. Thus, the correction can be made as indicated by the alternate long and short dash line in FIG. 11B, and the operating frequency of 4 kHz can be stably maintained.

Example 3
2 and 3 are the laser printer engine with the same optical system as in Example 1 in the configuration of the two types of micro mirror scanners, using ultraviolet laser light as the light source, mirror size of 2mm diameter, A4 vertical size Assuming a configuration that scans 600 dpi, a dot pitch of 42.3 μm, and a total number of dots of 7014.

  Similar to Example 1, when an fQ lens is used to correct the scanning speed, a voltage waveform is applied in a required pattern, the scanning speed at the end is increased to correct the scanning speed, and the fQ lens is not used. Both scans were performed. As a result, in any configuration, the deflection angle was 40 to 60 °, the reflectance was 90% or more, and the operating frequency was 5.5 kHz.

  The micromirror scanner according to the present invention, as is apparent from the embodiment used in the laser printer engine, can obtain an operating frequency equal to or higher than the current maximum rotational speed of the polygon mirror scanner, as compared with the conventional polygon mirror. The power consumption of the polygon scanner motor is 10-30W, while the micromirror scanner is excellent at 0.1W or less.

  Furthermore, the micro mirror scanner according to the present invention does not require a lens for correcting the tilt of the reflecting surface, and does not change the position of the reflecting surface of the mirror, and does not generate heat or generate dust in the optical unit. There is an advantage that simplification of the optical system is facilitated.

It is a perspective explanatory view of a substrate showing a configuration example of a micromirror scanner according to the present invention. It is a perspective view of a substrate showing another example of the configuration of the micromirror scanner according to the present invention. It is a perspective view of a substrate showing another example of the configuration of the micromirror scanner according to the present invention. It is explanatory drawing of the mirror and rotary drum which show the concept of scanning operation | movement, A shows the case where it is a conventional polygon mirror, B shows the case of the micromirror scanner by this invention. A to E are graphs showing examples of voltage waveforms for driving the micromirror scanner according to the present invention. It is a conceptual explanatory view showing an example of driving when a half mirror configuration is used in the micromirror scanner according to the present invention. It is a conceptual explanatory view showing an example of driving when multiple laser beams are incident on the micromirror scanner according to the present invention. It is a conceptual explanatory view showing a driving example when different wavelength laser light is incident on the micromirror scanner according to the present invention. It is a conceptual explanatory view showing an example of driving when light for mirror position detection is incident on the micromirror scanner according to the present invention. FIGS. 7A and 7B are conceptual explanatory diagrams illustrating a driving example of a micro mirror scanner in which micro mirrors are coaxial and have two different electrostatic driving sources. FIGS. A is a graph showing the relationship between the speed difference with respect to the drum center (angle 0) and the laser position φ, and B is a graph showing the relationship between the micromirror temperature and the resonance frequency. A to C are explanatory views showing a configuration of a conventional micromirror scanner.

Explanation of symbols

1 Micromirror scanner
2,21 substrate
3,33 Micromirror
4,6 groove
5,8,9 suspension beam
7 frames
10, 11, 12, 13 Comb electrode
22 Planar electrode
30 Polygon mirror
31 Rotating drum
34 Photo detector
35 Position detection beam
36 Position detector
37 Flat photoconductor

Claims (27)

When applying a voltage between the electrodes for electrostatic drive in order to drive the mirror to swing with respect to the electrostatic drive type micro mirror scanner in which a mirror supported on a semiconductor substrate so as to be swingable by a suspension beam, A method for controlling a micro mirror scanner, which transforms a voltage waveform to be applied into a required pattern or selects and applies a required pattern to control a swinging motion of the mirror. When applying a voltage between the electrodes for electrostatic drive in order to drive the mirror to swing with respect to the electrostatic drive type micro mirror scanner in which a mirror supported on a semiconductor substrate so as to be swingable by a suspension beam, The applied voltage waveform is transformed into a required pattern, or a required pattern is selected and applied, and a voltage waveform of the required pattern for correcting the oscillation motion according to the device temperature or a temperature in the vicinity thereof is further applied. And a control method of the micro mirror scanner for controlling the swinging motion of the mirror. 3. The method of controlling a micro mirror scanner according to claim 1, wherein the micro mirror scanner is a micro mirror scanner in which a micro mirror and a suspension beam are formed by a groove provided on a substrate, and an electrostatic driving electrode is disposed in the groove. A micromirror and a suspension beam are formed by grooves provided on the substrate, and a second suspension beam is formed by disposing a groove on the outer periphery of the micromirror and the suspension beam, and an electrostatic drive electrode is provided in each groove. 3. The micromirror scanner control method according to claim 1, wherein the micromirror scanner is a micromirror scanner having a coaxial configuration and two different electrostatic drive sources. A micromirror and a suspension beam are formed by grooves provided on the substrate, and a second suspension beam is formed by disposing a groove on the outer periphery of the micromirror and the suspension beam, and an electrostatic drive electrode is provided in each groove. 3. The method of controlling a micro mirror scanner according to claim 1, wherein the micro mirror is a micro mirror scanner having two different electrostatic drive sources in two orthogonal axes. 6. The method of controlling a micro mirror scanner according to claim 3, wherein the electrostatic drive electrode disposed in the groove is a micro mirror scanner configured to be disposed along the suspension beam. 7. The micromirror scanner control according to claim 3, wherein the micromirror scanner is a micromirror scanner in which another substrate is laminated on a substrate provided with a micromirror, and a planar electrode is disposed opposite to the non-reflecting surface of the mirror. Method. 8. The micromirror scanner according to claim 3, wherein the micromirror scanner is a micromirror scanner in which the micromirror, the suspension beam, the groove, and the electrostatic drive electrode are formed by a micromachining technique of film formation and / or etching. Control method. 3. The method of controlling a micro mirror scanner according to claim 1, further comprising a method of controlling a swing operation by taking out and monitoring a part of the laser light incident or reflected on the mirror. 3. The method of controlling a micro mirror scanner according to claim 1, wherein the mirror swing scanning operation is unidirectional, the voltage waveform is a rectangular wave or a sine wave, and the return voltage is increased to increase the scan effective time. The mirror swing scanning operation is unidirectional, the voltage waveform is a stepped rectangular wave or sine wave, and after the effective scan is completed, the return voltage is raised to stop, change direction, and re-accelerate. The control method of the micromirror scanner described in 1. The scanning operation is unidirectional, the voltage waveform is a pulsed rectangular wave or sine wave, the voltage at the middle part of the effective scan is lowered to lower the scan speed, and the scan speed is kept constant. The control method of the micromirror scanner described in 1. 3. The method of controlling a micromirror scanner according to claim 1, wherein the laser light that enters and reflects and emits light is a laser of a plurality of lights. 3. The laser beam according to claim 1, wherein the incident laser beam is a combined laser beam of different wavelength light, and a plurality of laser beams are reflected and emitted by using a diffraction grating for a mirror or a diffraction grating for a reflection optical path. Control method of micro mirror scanner. 3. The method of controlling a micro mirror scanner according to claim 1, wherein a light beam for detecting a mirror position is input to the incident laser beam, and the position detection light beam is separately detected. 6. The method of controlling a micro mirror scanner according to claim 5, wherein the micro mirror oscillating motion is corrected by an oscillating motion in an axial direction perpendicular to the mirror driving suspension beam to enable reciprocal scanning. 6. The method of controlling a micro mirror scanner according to claim 5, wherein the micro mirror scanner's swing motion and the swing motion in the axial direction perpendicular to the mirror drive suspension beam are added to enable two-dimensional scanning. 3. The method for controlling a micro mirror scanner according to claim 1, wherein the micro mirror scanner is a device incorporated in a scanner driver. 3. The method for controlling a micro mirror scanner according to claim 1, wherein the micro mirror scanner is a device incorporated in a printer driver. Electrostatic drive type micro mirror scanner in which a mirror is supported on a semiconductor substrate so as to be swingable by a suspension beam by using a micromachining technique for film formation and / or etching, and an electrode for electrostatic drive for swinging the mirror A micromirror scanner having means for applying a voltage waveform deformed into a required pattern or means for selecting and applying a voltage waveform deformed into a required pattern. 21. The micromirror scanner control method according to claim 20, wherein the micromirror scanner is a micromirror scanner in which a micromirror and a suspension beam are formed by a groove provided on a substrate, and an electrostatic drive electrode is disposed in the groove. A micromirror and a suspension beam are formed by grooves provided on the substrate, and a second suspension beam is formed by disposing a groove on the outer periphery of the micromirror and the suspension beam, and an electrostatic drive electrode is provided in each groove. 21. The method of controlling a micromirror scanner according to claim 20, wherein the micromirror scanner is a micromirror scanner in which the micromirror is coaxial and has two different electrostatic drive sources. A micromirror and a suspension beam are formed by grooves provided on the substrate, and a second suspension beam is formed by disposing a groove on the outer periphery of the micromirror and the suspension beam, and an electrostatic drive electrode is provided in each groove. 21. The method of controlling a micromirror scanner according to claim 20, wherein the micromirror scanner is a micromirror scanner having two different electrostatic drive sources in two orthogonal axes. 24. The method of controlling a micro mirror scanner according to claim 21, wherein the electrostatic drive electrode disposed in the groove is a micro mirror scanner configured to be disposed along the suspension beam. 25. The control of a micro mirror scanner according to claim 21, wherein the micro mirror scanner is a micro mirror scanner in which another substrate is laminated on a substrate provided with a micro mirror, and a planar electrode is disposed opposite to the non-reflecting surface side of the mirror. Method. 25. The method of controlling a micro mirror scanner according to claim 21, wherein a mirror size of the micro mirror is 4 mm square or less. 25. The method for controlling a micro mirror scanner according to claim 21, wherein the micro mirror has a mirror size of 2 mm square or less.

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