JP2012078515A - Resonant reflection device, optical gas analysis device and image scanner using the same, and control method for resonant reflection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resonant reflection device which makes a movable part stably vibrate, an optical gas analysis device and image scanner using the same, and a control method for the resonant reflection device.SOLUTION: The resonant reflection device comprises: reflection means having a fixed section, a torsion bar whose one end is connected to the fixed section, and a movable section which is connected to the other end of the torsion bar, is a plate member that rotates with respect to the fixed section with a connection section with the torsion bar as a rotation axis, and reflects light by at least one surface, and a driving section that rotates the movable section by being supplied with an AC current; temperature detection means for contactlessly detecting a temperature of the movable section of the reflection means; and control means that adjusts the magnitude of a bias current to be added to the AC current to be supplied to the driving section based on the temperature of the movable section detected by the temperature detection means.

Description

  The present invention relates to a resonance reflection apparatus that vibrates reflected light by vibrating a reflection part that reflects incident light, an optical gas analyzer using the same, an image scanner, and a control method for the resonance reflection apparatus.

  There is a device using MEMS (Micro Electro Mechanical Systems) as a resonant reflection device that vibrates reflected light by vibrating a reflecting portion that reflects incident light. In this resonant reflection device, a movable portion having a reflective surface and a fixed portion are connected by a torsion bar, and the movable portion is rotated about the torsion bar as a rotation axis to vibrate the reflective surface (Patent Document 1, Patent). Reference 2). Further, the resonant reflection device vibrates the movable part by arranging a magnet in the fixed part, arranging a coil in the movable part, and controlling a current supplied to the coil.

JP 2005-331679 A JP 2004-334966 A

  Here, the resonant reflection device vibrates at the resonance frequency of the movable part in order to vibrate efficiently in order to stably vibrate the movable part, that is, in a predetermined cycle. For this reason, the resonant reflection device detects the vibration state of the movable part, and controls the current supplied to the coil based on the detection result.

  However, the vibration state of the movable part changes depending on the driving conditions. Here, when the driving condition changes, the vibration angle changes minutely even when the vibration is caused in the resonance state. Therefore, even if the resonance state is maintained, it becomes difficult to control the amplitude angle of the movable part with high accuracy. Further, when a change in the vibration state of the movable part is detected and the drive is controlled based on the change, a time delay occurs. When the vibration state of the movable part changes in this way, it becomes difficult to use the reflected light under certain conditions.

  The present invention has been made in view of the above, and a resonant reflection apparatus that can vibrate a movable part more stably, an optical gas analyzer using the same, an image scanner, and a control of the resonant reflection apparatus It aims to provide a method.

  In order to solve the above-described problems and achieve the object, the present invention provides a fixed portion, a torsion bar having one end connected to the fixed portion, and the other end of the torsion bar. And a movable part that reflects light on at least one surface, and an alternating current is supplied to rotate the movable part. Reflecting means comprising a driving unit to be moved, temperature detecting means for detecting the temperature of the movable part of the reflecting means in a non-contact manner, and the driving unit based on the temperature of the movable part detected by the temperature detecting means And a control means for adjusting the magnitude of the bias current added to the alternating current to be supplied. Thereby, a movable part can be vibrated more stably and it can suppress that the amplitude of a movable part increases / decreases.

  Here, the drive unit is configured by a magnet disposed in the fixed unit and a coil disposed in the movable unit, an alternating current is supplied to the coil, and a Lorentz is provided between the coil and the magnet. It is preferable that the movable part is rotated with respect to the fixed part by generating a force. Thereby, a movable part can be rotated more appropriately.

  Further, the control means detects a counter electromotive force supplied from the drive unit, detects a detected counter electromotive force, a deviation between an alternating current and a phase, and detects the detected counter electromotive force based on the detected result. It is preferable to calculate an alternating current that further reduces a phase shift from the alternating current and supply the alternating current calculated from the drive unit. Thereby, a movable part can be vibrated more stably and it can suppress that the amplitude of a movable part increases / decreases. Furthermore, it can be vibrated more stably in the resonance state.

  Further, it is preferable that the control unit performs PID control based on a temperature of the movable part detected by the temperature detection unit and a preset temperature, and adjusts the bias current. Thereby, a movable part can be vibrated more stably and it can suppress that the amplitude of a movable part increases / decreases.

  Moreover, it is preferable that the said temperature detection means detects the temperature on the rotating shaft of the said movable part. Thereby, a movable part can be vibrated more stably and it can suppress that the amplitude of a movable part increases / decreases.

  Alternatively, the present invention provides a measurement cell that contains a gas to be measured or in which a gas to be measured flows, a light emitting unit that emits light in a wide wavelength band, and the light emitted from the light emitting unit. An optical system that guides the cell, a light receiving unit that receives light incident from the optical system and passed through the measurement cell, and an analysis that analyzes the gas flowing through the measurement cell based on information acquired by the light receiving unit And the optical system includes a resonant reflection device according to any one of the above, and a diffraction grating that diffracts the light reflected by the resonant reflection device, the movable portion of the resonant reflection device being By oscillating and changing the angle at which the light emitted from the light emitting unit is reflected, and changing the angle of the light reaching the diffraction grating, the light diffracted by the diffraction grating and incident on the measurement cell To change the wavelength And butterflies. Thereby, gas can be analyzed with higher accuracy.

  According to another aspect of the present invention, there is provided an image scanner for acquiring an image of a subject while scanning a reading position of the subject, the resonant reflection device according to any one of the above, and photoelectric conversion for converting incident light into a signal. And the movable part of the resonant reflection device are vibrated, reflected by the movable part of the resonant reflection device, and scanned by the reading position of the subject incident on the photoelectric conversion unit, to acquire image information of the subject And a control unit. Thereby, an image can be read with higher accuracy.

  In order to solve the above-described problems and achieve the object, the present invention provides a fixed portion, a torsion bar having one end connected to the fixed portion, and the other end of the torsion bar. And a movable part that reflects light on at least one surface, and an alternating current is supplied to rotate the movable part. A method of controlling a resonant reflection device that includes a reflection means having a drive unit to be moved and reflects light by rotating the movable part, wherein the temperature of the movable part of the reflection means is detected in a non-contact manner. And a step of adjusting a magnitude of a bias current to be added to an alternating current supplied to the drive unit based on the temperature of the movable unit detected in the temperature detection step. DoThereby, a movable part can be vibrated more stably and it can suppress that the amplitude of a movable part increases / decreases.

  The resonant reflection device, the optical gas analyzer using the same, the image scanner, and the control method for the resonant reflection device according to the present invention have an effect that the movable part can be vibrated more stably.

FIG. 1 is a schematic diagram showing a schematic configuration of an embodiment of a resonant reflection apparatus. FIG. 2 is a front view showing a schematic configuration of the reflecting means shown in FIG. FIG. 3 is a cross-sectional view showing a schematic configuration of the reflecting means shown in FIG. FIG. 4 is a graph showing an example of current supplied from the reflection means driver of the resonant reflection apparatus shown in FIG. FIG. 5 is a graph showing the relationship between the temperature change and the amplitude at the time of resonance of the movable part. FIG. 6 is a flowchart showing the operation of the feedback control unit. FIG. 7 is an explanatory diagram showing the relationship between resonance and back electromotive force. FIG. 8 is a schematic diagram showing a schematic configuration of an embodiment of a gas analyzer having a resonant reflection device. FIG. 9 is a schematic diagram showing a schematic configuration of the diffraction section shown in FIG. FIG. 10 is an explanatory diagram showing the relationship between the emitted light wavelength and time. FIG. 11 is a schematic diagram showing a schematic configuration of an embodiment of an image scanner having a resonant reflection device.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the following modes for carrying out the invention (hereinafter referred to as embodiments). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the constituent elements disclosed in the following embodiments can be appropriately combined.

(Embodiment 1)
FIG. 1 is a schematic diagram showing a schematic configuration of an embodiment of a resonant reflection apparatus. The resonant reflection device 10 shown in FIG. 1 includes a reflection unit 12 that reflects light on a rotating reflection surface, a temperature detection unit 14 that detects the temperature of the reflection unit 12 in a non-contact manner, and a temperature detected by the temperature detection unit 14. And control means 16 for controlling the operation of the reflection means 12 based on other control conditions.

  Hereinafter, the reflecting means 12 will be described with reference to FIGS. 2 and 3. 2 is a front view showing a schematic configuration of the reflecting means shown in FIG. 1, and FIG. 3 is a cross-sectional view showing a schematic configuration of the reflecting means shown in FIG. As shown in FIGS. 2 and 3, the reflecting means 12 includes a fixed portion 30, a movable portion 32, a torsion bar 34, a magnet 36, a magnet 38, and a coil 40.

  The fixed portion 30 is a plate-like member, and an opening is formed at the center. Moreover, the fixing | fixed part 30 is being fixed with respect to arbitrary support members (illustration omitted). The support member is a housing of a device provided with a resonant reflection device, a substrate, or the like. The movable portion 32 is a plate-like member disposed in the opening of the fixed portion 30, and one surface (surface, surface having the largest area) is a reflective surface 33. Here, the movable portion 32 basically has a reflective surface 33 that is not facing the temperature detecting means 14 among the two surfaces having the largest area. The movable part 32 is smaller than the opening of the fixed part 30, and a space is formed between the movable part 32 and the fixed part 30. Each of the two torsion bars 34 is disposed at an intermediate point on the side surface of the movable portion 32, and connects the fixed portion 30 and the movable portion 32. The two torsion bars 34 are arranged on two parallel surfaces of the four sides of the movable portion 32, and each connects the movable portion 32 and the fixed portion 30 facing the movable portion 32. is doing. The torsion bar 34 is a member that deforms in the twisting direction. In this embodiment, the torsion bar 34 is deformed around the axis with the direction connecting the two torsion bars 34 as an axis.

The fixed portion 30, the movable portion 32, and the torsion bar 34 are arranged in the above relationship, and the movable portion 32 is arranged in the opening of the fixed portion 30, and the two torsion bars 34 It is fixed with respect to the fixing part 30. Further, since the two torsion bars 34 can be deformed in the rotational direction with respect to the axis connecting the two torsion bars 34, the movable part 32 connects the two torsion bars 34 to the fixed part 30. It becomes possible to rotate around the line. That is, as shown in FIG. 3, the movable portion 32 can rotate in the direction of the arrow 42. Thereby, the movable part 32 can be reciprocated from the position of the movable part 32a to the position of the movable part 32b, for example, and can be rotated (vibrated). The reflecting surface 33 of the movable portion 32 reflects the light L ₁ incident.

  Next, the magnet 36 and the magnet 38 are arranged in the vicinity of the surface of the fixed portion 30 facing two side surfaces that are not connected to the torsion bar 34 among the four side surfaces of the movable portion 32. The coil 40 is disposed along the side surface of the movable part 32, that is, along the outer periphery. The coil 40 is connected to the control means 16, and current is supplied from the control means 16.

  The reflecting means 12 is supplied with a current from the control means 16, thereby generating a Lorentz force between the coil 40 and the magnet 36 or between the coil 40 and the magnet 38. As a result, a force in a direction perpendicular to the direction of the magnetic field and current is generated between the fixed portion 30 and the movable portion 32, particularly on the two surfaces of the four side surfaces where the magnets 36 and 38 are disposed. A force in the direction of the arrow 42 is generated between the fixed portion 30 and the movable portion 32 on the surface on which 36 and 38 are disposed. Further, by making the current supplied from the control means 16 an alternating current, the generated Lorentz force can be changed periodically, and the movable part 32 can be rotated with respect to the fixed part 30 about the torsion bar 34 as an axis. .

  The description of the resonant reflection device 10 will be continued using FIGS. 1 and 2. The temperature detection means 14 is a temperature detection mechanism that detects the temperature in a non-contact manner, and serves as a rotation axis among the temperature of the movable portion 32, specifically, the surface of the movable portion 32 opposite to the reflection surface 24. The temperature of the part (on the line connecting the two torsion bars 34) is detected. In addition, as the temperature detection means 14, the various thermometers which detect temperature non-contactingly can be used, for example, an infrared radiation thermometer can be used.

  The control unit 16 includes a temperature setting unit 20, a feedback control unit 22, and a reflection unit driver 24. Based on the set temperature of the temperature setting unit 20 and the detection result of the temperature detection unit 14, the feedback control unit 22 The control conditions are determined, and then the operation of the reflection means 12 is controlled by the reflection means driver 24 in consideration of the determined control conditions. The temperature setting unit 20 is a setting unit that sets a set temperature (reference temperature) of the movable unit 32. The temperature setting unit 20 sets a set temperature based on a user input or preset conditions. The temperature setting unit 20 of the present embodiment sets the set temperature as a certain temperature range, and the upper limit value and the lower limit value of the set temperature are set.

  The feedback control unit 22 determines a control condition based on the set temperature of the temperature setting unit 20 and the detection result of the temperature detection unit 14. Specifically, the magnitude of a bias current (or a condition for determining the bias current) to be described later supplied to the coil 40 of the reflecting means 12 is determined. The feedback control unit 22 sends the calculation result to the reflection means driver 24. When the detection result of the temperature detection unit 14 is lower than the set temperature of the temperature setting unit 20, the feedback control unit 22 sets the magnitude (current value) of the bias current that increases the temperature of the movable unit 32, and detects the temperature. When the detection result of the means 14 is higher than the set temperature of the temperature setting unit 20, the magnitude (current value) of the bias current that lowers (or does not increase) the temperature of the movable unit 32 is set.

  The reflection means driver 24 is a control mechanism that controls the driving of the reflection means 12 and controls the current supplied to the coil 40 of the reflection means 12. The reflection means driver 24 supplies an alternating current having a frequency at which the movable portion 32 of the reflection means 12 vibrates due to resonance to the coil 40 of the reflection means 12. The reflection means driver 24 supplies a bias current superimposed on the alternating current. That is, as shown in FIG. 4, the reflection means driver 24 supplies the coil 40 with a current obtained by superimposing a bias current having a constant current value on an alternating current at a constant cycle in which the current value changes. Here, FIG. 4 is a graph showing an example of the current supplied from the reflection means driver of the resonant reflection apparatus shown in FIG. Note that the bias current is a value determined by the feedback control unit 22 as described above. The reflection means driver 24 calculates the resonance period based on the back electromotive force generated in the coil 40 and adjusts the frequency of the alternating current.

  As described above, the control unit 16 adjusts the magnitude of the bias current and adjusts the temperature of the movable unit 32 based on the temperature detected by the temperature detection unit 14 and the value set by the temperature setting unit 20. While supplying an alternating current, the movable part 32 of the reflecting means 12 is vibrated. That is, the control means 16 can heat the movable part 32 by supplying a bias current to the movable part 32, and can adjust the temperature of the movable part 32 by adjusting the heating amount. Note that the change in the slope due to the bias current generated by the adjustment is minute compared to the amplitude in the case of resonance. For this reason, the influence of the change in the bias current on the amplitude is negligible. For this reason, the bias current does not affect the driving (vibrating operation) of the reflecting means 12.

  The resonant reflection device 10 supplies the bias current in addition to the alternating current from the control unit 16 to the reflection unit 12 based on the temperature of the movable unit 32 detected by the temperature detection unit 14, thereby setting the temperature of the movable unit 32 to the set temperature. The movable part 32 can be vibrated while maintaining the above range. In addition, by maintaining the temperature of the movable part 32 within the range of the set temperature, the temperature state around the movable part 32 can be kept within a certain range, and the torsion bar 34 connected to the movable part 32, and further the torsion The temperature of the fixed part 30 connected to the bar 34 can also be set within a certain temperature range. Thereby, the change of the relative relationship of each part which vibrates the movable part 32 can be suppressed, that is, the expansion and contraction by heat, the change of elasticity can be suppressed, and the spring constant which vibrates the movable part 32 and A change in the moment of inertia around the rotation axis of the reflecting portion can be suppressed.

  Here, FIG. 5 is a graph showing the relationship between the temperature change and the amplitude at the time of resonance of the movable part. In FIG. 5, the vertical axis represents amplitude, and the horizontal axis represents drive frequency. The amplitude is the amplitude of the movable part 32. The drive frequency is the frequency of the alternating current supplied from the reflection means driver 24 to the coil 40. That is, FIG. 5 is a graph showing a result of measuring the amplitude of the movable portion 32 when an arbitrary drive frequency is supplied. The solid line 44 is a measurement result of the relationship between the drive frequency and amplitude when the temperature of the movable part 32 is t1 (° C.), and the solid line 46 is when the temperature of the movable part 32 is t2 (° C.). It is a measurement result of the relationship between the drive frequency and amplitude. The relationship between the temperature t1 and the temperature t2 is t1 <t2.

  As indicated by the solid line 44, the resonance frequency of the movable part 32 when the temperature of the movable part 32 is t1 (° C.) is the drive frequency having the largest amplitude, and is the frequency F1. Further, as indicated by the solid line 46, the resonance frequency of the movable part 32 when the temperature of the movable part 32 is t2 (° C.) is the drive frequency having the largest amplitude and is the frequency F2. As shown by the solid line 44 and the solid line 46, when the reflecting means 12 is driven at a drive frequency other than the resonance frequency, the amplitude is greatly reduced. Similarly to the temperature t1 and the temperature t2, a solid line 48 is obtained by connecting the relationship between the resonance frequency and the amplitude at each temperature. As shown in FIG. 5, the resonance frequency changes with temperature, and the amplitude at the resonance frequency also changes with temperature.

  Here, the reflection means 12 can maintain the resonance state by changing the drive frequency according to the temperature change, but the amplitude at the time of vibration at the resonance frequency changes. On the other hand, the resonant reflection apparatus 10 detects the temperature by the temperature detection means 14 and adjusts the bias current according to the temperature, thereby resonating the movable part 32 while suppressing the temperature change. Can do. Thereby, it is possible to resonate the movable portion 32 while suppressing changes in the resonance frequency and amplitude, and to drive the movable portion 32 stably. That is, changes in the vibration period and vibration width can be suppressed, and the movable portion 32 can be vibrated with more uniform vibration.

  In addition, since the change of the resonance frequency can be suppressed, the operation of following the deviation of the resonance frequency, that is, the operation of adjusting the drive frequency can be reduced or eliminated. Further, since the adjustment time can be shortened or eliminated, it is possible to drive in the resonance state for a longer time, and to suppress driving in the adjustment state.

  Further, the resonant reflection device 10 is movable without affecting the vibration operation of the reflection unit 12, that is, the vibration operation of the movable unit 32 by detecting the temperature of the movable unit 32 in a non-contact manner by the temperature detection unit 14. The temperature of the unit 32 can be detected. Here, the temperature detection means 14 preferably detects the temperature of the surface of the movable portion 32 opposite to the reflection surface 33 as in the present embodiment, and further detects the temperature on the rotation axis. preferable. By detecting the temperature of the surface opposite to the reflecting surface 33, it is possible to suppress the influence on incident light and reflected light. Further, by detecting the temperature on the rotation axis, it is possible to suppress the occurrence of a displacement of the measurement position when the movable part 32 vibrates. That is, the temperature at the same position can be measured. In addition, since the temperature detection means 14 can acquire the said effect, although it is preferable to measure the position similar to this embodiment of the movable part 32, it is not limited to this. For example, the temperature of the reflecting surface 33 of the movable part 32 may be measured, or the temperature of the torsion bar 34 may be measured. Moreover, you may measure the temperature of several points.

  Next, the temperature maintenance operation (temperature adjustment operation) by the resonant reflection device 10 will be described. Here, FIG. 6 is a flowchart showing the operation of the feedback control unit. First, the feedback control part 22 acquires the temperature information detected by the temperature detection means 14 as step S12. Note that the feedback control unit 22 acquires information on the set temperature set by the temperature setting unit 20. After acquiring the temperature information in step S12, the feedback control unit 22 determines whether the temperature detected in step S12 is higher than the upper limit value of the reference temperature as step S14. When it is determined that the temperature detected in step S14 is higher than the upper limit value of the reference temperature (Yes), the feedback control unit 22 reduces the bias current in step S16. Specifically, the set value of the bias current is made smaller than the previous value. The feedback control unit 22 ends the process after reducing the bias current in step S16.

  If the feedback control unit 22 determines that the temperature detected in step S14 is not higher than the upper limit value of the reference temperature (No), that is, is equal to or lower than the upper limit value of the reference temperature, the lower limit value of the reference temperature is set as step S18. It is judged whether it is lower than. When it is determined that the temperature detected in step S18 is lower than the lower limit value of the reference temperature (Yes), the feedback control unit 22 increases the bias current in step S20. Specifically, the set value of the bias current is made larger than the previous value. The feedback control unit 22 ends the process after increasing the bias current in step S20. Further, when the feedback control unit 22 determines that the temperature detected in step S18 is not lower than the lower limit of the reference value (No), that is, when it is determined that the temperature is equal to or higher than the lower limit of the reference value, the process is terminated. The feedback control unit 22 adjusts the value of the bias current by repeating this process every time temperature information is sent from the temperature detection unit 14 or every predetermined time.

  In the present embodiment, the temperature is controlled by on / off control with respect to the set temperature, but the present invention is not limited to this. The feedback control unit 22 may adjust the magnitude of the bias current by PID control. In this case, the feedback control unit 22 adjusts the bias current to be supplied based on the detected temperature and the set temperature. Specifically, the feedback control unit 22 uses the detected temperature and the set temperature to perform a calculation set by PID control, determines a bias current to be supplied, and supplies the determined bias current. The feedback control unit 22 can adjust the temperature of the movable unit with higher accuracy by adjusting the bias current by PID control, and can more appropriately suppress the temperature change of the movable unit.

  Next, an example of a drive frequency control method by the reflection means driver 24 will be described with reference to FIG. Here, FIG. 7 is an explanatory diagram showing the relationship between resonance and the counter electromotive force. As shown in the top graph of FIG. 7, an alternating current is supplied to the movable part 32 to vibrate the movable part 32. In the present embodiment, a square wave having a duty ratio smaller than 33% is supplied as an alternating current (drive voltage). When an alternating current is supplied to the movable portion 32, the movable portion 32 vibrates, and back electromotive force is generated by the vibration of the movable portion 32 as shown in the second graph from the top in FIG. The counter electromotive force changes in voltage value with the vibration of the movable part 32 as one cycle.

  As a result, the coil 40 is in a state where the back electromotive force and the drive voltage are superimposed. At this time, if the resonance frequency of the movable part 32 and the drive frequency coincide with each other, as shown in the third graph from the top in FIG. 7, the center of the square wave of the drive voltage coincides with the peak of the electromotive force in time. . On the other hand, if the resonance frequency of the movable part 32 and the drive frequency do not coincide with each other, the back electromotive force and the drive voltage (square shape) are obtained as shown in the fourth graph (lowermost) in FIG. Deviation occurs with the phase of the wave.

  In this way, the reflection means driver 24 detects the voltage flowing through the coil 40, detects whether the phase of the back electromotive force and the drive voltage matches based on the voltage change, and based on the detection result, By adjusting the frequency of the drive voltage, the movable part 32 can be vibrated at the resonance frequency. That is, the reflection means driver 24 detects the phase shift between the back electromotive force and the drive voltage from the voltage flowing through the coil 40 so that the phase shift approaches 0, that is, the back electromotive force and the alternating current. The movable portion 32 can be vibrated at the resonance frequency by changing the drive frequency (the frequency of the alternating current and the drive voltage) so as to reduce the phase shift.

  Note that, as described above, the resonant reflection device 10 adjusts the temperature of the movable portion 32 so that the resonant frequency does not change, so that it can be driven in a resonant state without adjusting the drive frequency. However, as in the above-described embodiment, by adjusting the drive frequency, the resonance state can be more reliably achieved, and the drive can be performed at a more appropriate drive frequency.

(Embodiment 2)
Next, the optical gas analyzer 100 using the resonant reflection device 10 will be described with reference to FIGS. 8 to 10. Here, FIG. 8 is a schematic diagram showing a schematic configuration of an embodiment of a gas analyzer having a resonant reflection device, and FIG. 9 is a schematic diagram showing a schematic configuration of the diffraction section shown in FIG. FIG. 10 is an explanatory diagram showing the relationship between the emitted light wavelength and time.

  The optical gas analyzer 100 is an analyzer that detects total hydrocarbon (THC: Total Hydro-Carbon) contained in a gas to be measured, and includes a measuring unit 101, a light source 102, a spectrometer 104, and a light receiving unit. 106 and an analysis control unit 130.

  The measurement unit 101 is a container that holds a gas to be measured, and includes a light incident unit 110 that allows light to enter and a light output unit 112 that emits light that has passed through the inside of the container. Note that the measuring unit 101 is not limited to a container for confining the measurement target gas, and may be a pipe through which the measurement target gas flows. Further, when the atmosphere is a measurement target, a box or a pipe line may not be provided as the measurement unit 101.

  The light source 102 is a light emitting element that emits light in a wide wavelength band. Note that light in a wide wavelength band is light including a wavelength component capable of detecting the measurement target gas. As light, light in various wavelength regions such as an infrared region, a visible light region, and an ultraviolet region can be used. Further, as the light source 102, various light emitting elements can be used, and the light can be dispersed by a spectroscope 104 described later and only light in a necessary wavelength range can be used. Therefore, wavelengths other than the wavelength range to be measured can also be used. A light-emitting element that outputs light including the light can be used.

  Next, as shown in FIGS. 8 and 9, the spectroscope 104 includes the resonant reflection device 10, the diffraction unit 120, and the optical system 122. In addition, the structure of each part of the resonant reflective apparatus 10 is the same structure as the resonant reflective apparatus 10 mentioned above. Therefore, detailed description of the resonant reflection device 10 is omitted. The resonant reflection device 10 reflects light output from the light source 102 by the reflection means 12. In addition, since the rotation part which reflects light vibrates (rotates) the reflection means 12, the reflection angle which reflects the light output from the light source 102 changes periodically. Further, the light output from the light source 102 becomes parallel light when it reaches the reflecting means 12.

  The diffraction unit 120 is a grating that diffracts and reflects incident light, and is disposed on the passage path of the light reflected by the resonant reflection device 10. When the reflection angle of the reflection means 12 of the resonant reflection device 10 changes, the diffraction unit 120 changes the incident angle of the light reflected by the resonant reflection device 10. The diffraction unit 120 selects the wavelength of light to be reflected according to the incident angle of light. That is, the diffraction unit 120 reflects light having different wavelengths according to the incident angle of light.

  The optical system 122 is disposed on the passage path of the light diffracted and reflected by the diffraction unit 120, and includes two collimator lenses and a pinhole. The optical system 122 condenses the light diffracted and reflected by the diffraction unit 120 with one collimator lens, passes through the pinhole, and then converts it into parallel light with the other collimator lens. Accordingly, the optical system 122 can output only light of a predetermined component among the light diffracted and reflected by the diffraction unit 120. That is, light that reaches the optical system 122 without being diffracted by the diffraction unit 120 and light that reaches the optical system 122 after irregular reflection cannot pass through the pinhole. Alternatively, since the collimator lens does not produce parallel light, the optical system 122 can output only selected light (light reflected by the resonant reflection device 10 and diffracted by the diffraction unit 120). The light emitted from the optical system 122 is incident on the measurement unit 101.

  The spectroscope 104 is configured as described above, and periodically changes the angle of light reaching the diffractive portion 120 by the resonant reflection device 10 so that light output through the optical system 122 is output to the outside. , It can be light whose wavelength changes periodically. That is, the light whose wavelength is selected can be output while sweeping the wavelength at a constant period.

  The light receiving unit 106 is a photoelectric converter, and is disposed at a position where the light emitted from the spectroscope 104 and passed through the measurement unit 101, that is, the light (measurement light) output from the light output unit 112 arrives. The light receiving unit 106 receives the light (measurement light) output from the light output unit 112, converts the received light into an electrical signal, and sends it to the analysis control unit 130.

  The analysis control unit 130 is a control unit that controls operations of the light source 102, the spectroscope 104, and the light receiving unit 106. In addition, the analysis control unit 130 receives the light reception signal sent from the light receiving unit 106, the conditions for driving the light source 102, the conditions for the spectroscope 104 (relationship between the driving conditions for the resonant reflection device 10, the measurement timing, and the reflection angle). Based on the above, the analysis is performed and the gas to be measured is analyzed. For example, the analysis control unit 130 calculates the concentration of hydrocarbons contained in the measurement gas. Specifically, the analysis control unit 130 calculates the wavelength and intensity of light incident on the measurement unit 101 based on various conditions, and compares the calculated light intensity with the intensity of light received by the light receiving unit 106. The attenuation (light absorption) of the wavelength of the incident light is calculated by the gas to be measured. The analysis control unit 130 repeats such analysis for each wavelength while continuously changing the wavelength of the light incident by the spectrometer 104, so that the absorption rate of the gas to be measured in a certain wavelength range can be reduced. Calculate the distribution. Furthermore, the analysis control unit 130 calculates the total amount of hydrocarbons contained in the gas by analyzing the absorption rate for each wavelength. The analysis control unit 130 stores information on the wavelength to be absorbed and the intensity of the absorption for each substance, and analyzes the gas component by using the relationship and the absorption rate for each wavelength. can do.

  The optical gas analyzer 100 analyzes the components of the measurement gas by detecting the absorption rate of the measurement target gas at each wavelength while sweeping the wavelength of the measurement light at a constant period, and analyzing the detection result. be able to. In this embodiment, the total amount of hydrocarbons can be calculated.

  Furthermore, by using the resonant reflection device 10, it is possible to suppress a change in the amplitude of the movable portion 32 due to a temperature change, and to stabilize the change width of the angle of light incident on the diffraction portion 120. Thereby, as shown in FIG. 10, it can suppress that the range of the emitted light wavelength (wavelength of the light which injects into the measurement part 101) changes with temperature changes. That is, when the amplitude of the movable part 32 changes due to a temperature change, the angle width of the light incident on the diffraction part 120 also increases or decreases. When the angle width of the light incident on the diffraction unit 120 is increased or decreased, the wavelength width of the light diffracted by the diffraction unit 120 and reaching the optical system 122 is also increased or decreased. When the width of the wavelength to be swept changes as the temperature changes in this way, an error occurs between the calculation result of the wavelength distribution of the detection result and the actual result. On the other hand, since the optical gas analyzer 100 can suppress the change in the amplitude of the movable part 32 due to the temperature change, the optical gas analyzer 100 can suppress the change in the width of the wavelength to be swept. An error that occurs between the calculation result of the wavelength distribution of the detection result and the actual result can be suppressed. That is, the measurement error can be further reduced.

  Further, the optical gas analyzer 100 can use various substances as a measurement target, and is not limited to hydrocarbons, but also measures concentrations of nitrogen oxides, sulfide oxides, carbon monoxide, carbon dioxide, ammonia, and the like. can do. The optical gas analyzer 100 can measure hydrocarbons that are attached to a diesel engine and that flow through a fuel path that supplies the diesel engine. The optical gas analyzer 100 may measure substances contained in the exhaust gas discharged from the diesel engine. The engine that discharges exhaust gas, that is, a device that discharges (supplies) the gas to be measured is not limited to this, and can be used for various internal combustion engines such as a gasoline engine and a gas turbine. Examples of the device having an internal combustion engine include various devices such as vehicles, ships, and generators. Furthermore, the density | concentration of the predetermined substance contained in the waste gas discharged | emitted from a garbage incinerator can also be measured.

(Embodiment 3)
Next, the image scanner 200 using the resonant reflection device 10 will be described with reference to FIG. Here, FIG. 11 is a schematic diagram showing a schematic configuration of an embodiment of an image scanner having a resonant reflection device. The image scanner 200 is an image reading device that reads an image of a subject 230, and includes a resonant reflection device 10, a light receiving unit 210, an amplifier 212, a data integration unit 214, an image information processing unit 216, and a scanner control unit 220. Have. The image scanner 200 further includes a light source that illuminates the subject 230, a relative movement mechanism that scans the subject 230 or the reading unit, an operation unit that inputs operation instructions, a display unit that displays detection results, and the like. It has each part necessary for 200.

  The resonant reflection device 10 causes the movable unit 32 to vibrate to scan the position of the subject 230 received by the light receiving unit 210 out of the light reflected from the subject 230. That is, the resonant reflection device 10 scans the position where the light receiving unit 210 reads an image by vibrating the movable unit 32. In addition, the structure of each part of the resonant reflective apparatus 10 is the same structure as the resonant reflective apparatus 10 mentioned above.

  The light receiving unit 210 is a photoelectric converter, receives light reflected from the resonant reflection device 10 from the subject 230, receives the light reflected by the resonance reflection device 10, converts the received light into an electrical signal, and sends it to the amplifier 212. .

  The amplifier 212 amplifies the electrical signal output from the light receiving unit 210 and sends it to the data integration unit 214. The data integration unit 214 acquires information on the color and brightness of the image from the electronic signal received from the amplifier 212, and further acquires information on the angle (amplitude phase) of the movable unit 32 from the reflection means driver 24 of the resonant reflection device 10. To do. The data integration unit 214 associates the color and brightness information of the image with the position information based on the information on the angle (amplitude phase) of the movable unit 32 and sends it to the image information processing unit 216. The image information processing unit 216 sequentially stores the position associated with the data integration unit 214, the color information of the image, and the brightness information.

  The scanner control unit 220 controls operations of the resonant reflection device 10, the light receiving unit 210, the amplifier 212, the data integration unit 214, and the image information processing unit 216. The scanner control unit 220 vibrates the movable part of the resonant reflection device 10, reads an image at each position by the light receiving unit 210, sequentially processes the amplifier 212, the data integration unit 214, and the image information processing unit 216, By reading the image information at each position of the subject 230, the image of the subject 230 can be read. In the present embodiment, the resonant reflection device 10 is configured to vibrate in one direction (on one line), but the angle of the resonant reflection device 10 (reflection means 12) can be changed, or the reflection means 12 and the subject. The image information of the entire surface of the subject 230 can be acquired by moving the head 230 relatively.

  Here, the image scanner 200 can suppress a change in the amplitude of the movable portion 32 due to a temperature change by using the resonant reflection device 10. By suppressing the change in the amplitude of the movable portion 32, the image width read by the light receiving portion 210 can be made constant. In addition, a change in reading position in one cycle can be suppressed. As described above, since the read image width can be made constant, an error generated between the calculation result of the data integration unit and the actual result can be further reduced. Thereby, it can suppress that a read image becomes an image extended rather than an actual image, or it becomes a shrunken image.

  As described above, the resonant reflector, the optical gas analyzer using the same, the image scanner, and the resonant reflector control method according to the present invention reflect incident light while changing the reflection angle at a constant period. Useful for.

DESCRIPTION OF SYMBOLS 10 Resonance reflection apparatus 12 Reflection means 14 Temperature detection means 16 Control means 20 Temperature setting part 22 Feedback control part 24 Reflection means driver 30 Fixed part 32 Movable part 34 Torsion bar 36, 38 Magnet 40 Coil 42 Arrow 44, 46, 48 Solid line 100 Optical gas analyzer 101 Measuring unit 102 Light source 104 Spectrometer 106 Light receiving unit 110 Light receiving unit 112 Light emitting unit 120 Diffraction unit 122 Optical system 130 Analysis control unit 200 Image scanner 210 Light receiving unit 212 Amplifier 214 Data integration unit 216 Image information processing unit 220 Scanner control unit 230 Subject

Claims (8)

A fixed part, a torsion bar having one end connected to the fixed part, a plate connected to the other end of the torsion bar, and rotating with respect to the fixed part around the connecting part with the torsion bar A reflecting member including a movable part that reflects light on at least one surface, and a drive part that rotates the movable part by being supplied with an alternating current;
Temperature detecting means for detecting the temperature of the movable part of the reflecting means in a non-contact manner;
And a control unit that adjusts the magnitude of a bias current added to the alternating current supplied to the drive unit based on the temperature of the movable unit detected by the temperature detection unit.   The drive unit includes a magnet disposed on the fixed unit and a coil disposed on the movable unit, and an alternating current is supplied to the coil, and a Lorentz force is generated between the coil and the magnet. The resonant reflection apparatus according to claim 1, wherein the movable portion is rotated with respect to the fixed portion.   The control means detects a counter electromotive force supplied from the drive unit, detects a detected counter electromotive force, a shift in an alternating current and a phase, and based on the detected result, a detected counter electromotive force, The resonant reflection device according to claim 1, wherein an alternating current that reduces a phase shift from the alternating current is calculated, and the alternating current calculated from the driving unit is supplied.   4. The control unit according to claim 1, wherein the control unit performs PID control based on a temperature of the movable part detected by the temperature detection unit and a preset temperature, and adjusts the bias current. 5. The resonance reflective apparatus of any one of Claims.   5. The resonant reflection apparatus according to claim 1, wherein the temperature detection unit detects a temperature on a rotation axis of the movable part. A measurement cell containing the gas to be measured; and
A light emitting unit that emits light in a wide wavelength band;
An optical system for guiding the light emitted from the light emitting unit to the measurement cell;
A light receiving unit that receives light incident from the optical system and passed through the measurement cell;
Based on the information acquired by the light receiving unit, an analysis unit for analyzing the gas flowing through the measurement cell,
The optical system includes the resonant reflection device according to any one of claims 1 to 5 and a diffraction grating that diffracts the light reflected by the resonant reflection device, and vibrates a movable part of the resonant reflection device. The wavelength of light that is diffracted by the diffraction grating and incident on the measurement cell is changed by changing the angle at which the light emitted from the light emitting unit is reflected and changing the angle of the light that reaches the diffraction grating. An optical gas analyzer characterized by changing the temperature. An image scanner that acquires an image of the subject while scanning a reading position of the subject,
Resonant reflection device according to any one of claims 1 to 5,
A photoelectric conversion unit that converts incident light into a signal;
A control unit that vibrates a movable portion of the resonant reflection device, reflects the reflected light by the movable portion of the resonant reflection device, scans the reading position of the subject incident on the photoelectric conversion unit, and acquires image information of the subject; And an image scanner. A fixed part, a torsion bar having one end connected to the fixed part, a plate connected to the other end of the torsion bar, and rotating with respect to the fixed part around the connecting part with the torsion bar A movable member that reflects light on at least one surface, and a reflection unit that includes a drive unit that rotates the movable unit when supplied with an alternating current, and rotates the movable unit. A method of controlling a resonant reflection device that reflects light,
A temperature detecting step for detecting the temperature of the movable part of the reflecting means in a non-contact manner;
Adjusting the magnitude of a bias current to be added to the alternating current supplied to the drive unit based on the temperature of the movable unit detected in the temperature detection step. Method.

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