JP2005316318A - Shutter device and driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shutter device capable of restraining the occurrences of stray light and to provide a drive device. <P>SOLUTION: The shutter device includes: a first stator (1a) having a luminous flux passage area and provided with a first drive electrode (4a); a first electret film (24a) which is driven by the first drive electrode and runs on a face on which the first drive electrode is disposed; a second stator (1b) having a luminous flux passage area and provided with a second drive electrode (4b) disposed opposite the first drive electrode; a second electret film (24b) which runs on a face on which the second drive electrode is disposed; and a partition plate (25) having a luminous flux passage area and disposed between the first drive electrode face of the first stator and the second drive electrode face of the second stator so as to separate the first electret film and the second electret film from each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a shutter device and a drive device using an electret film.

As a technique related to a shutter mechanism of a camera, a technique is disclosed in which a slider is driven using the principle of operation of an inductive charge actuator and the slider functions as a shutter blade. In this technique, an electrode is formed on the surface of the glass-epoxy substrate and the first slider is disposed opposite to the electrode, and an electrode is formed on the back surface and the second slider is disposed opposite to the electrode. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 8-220592

  The technique described in Patent Document 1 describes an example applied to a lens shutter with an aperture function, but it can also be applied as a focal plane type shutter mechanism by using two sliders as a front curtain and a rear curtain. It is possible.

  However, since it is necessary to form electrode patterns on both sides of the glass-epoxy substrate, there is a limit to reducing the thickness. For this reason, when this technology is applied to a focal plane type shutter mechanism, the distance between the two light-shielding curtains becomes relatively large, and stray light is likely to be generated.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a shutter device and a driving device that can reduce the distance between two sliders and suppress the generation of stray light. .

  In order to solve the above-mentioned problems, a shutter device according to claim 1 of the present invention is a shutter device using an electret film as a shutter curtain. The shutter device has a light beam passage region and is used for driving the electret film. A first stator provided with one drive electrode, a first electret film driven and driven by the first drive electrode on a surface provided with the first drive electrode, and a light flux passage region And a second stator provided with a second drive electrode so as to face the first drive electrode, and a surface on which the second drive electrode is provided by the second drive electrode. Between the second electret film that is driven to travel, the first drive electrode surface of the first stator and the second drive electrode surface of the second stator, and the first drive electrode surface. Elek Let the film and be arranged so as to separate the two electret films between the second electret film had a partition plate having a light beam passage region.

  According to a second aspect of the present invention, there is provided a shutter device using an electret film as a shutter curtain, wherein the shutter device has a light flux passage region, and the first drive electrode for driving the electret film is one of the shutter devices. A first stator provided on a surface, a first electret film traveling on a surface provided with the first drive electrode, and the first stator with one surface and the first stator. A partition plate arranged so as to sandwich the electret film, a second electret film that travels on the other surface side of the partition plate, the surface provided with the second drive electrode, and the partition plate And a second stator arranged so as to sandwich two electret films.

  A shutter device according to a third aspect of the present invention is the shutter device according to the above-described invention, wherein the second stator and the partition plate are provided between the first stator and the partition plate. A spacer member having elasticity is provided between the two.

  According to a fourth aspect of the present invention, there is provided a driving device according to a fourth aspect of the present invention, in the driving device using the electret film as a slider, a first stator provided with a first driving electrode for driving the electret film, A first electret film that is driven by the first drive electrode and travels on the surface on which the first drive electrode is provided, and for driving the electret film so as to face the first drive electrode. Between the second stator provided with the second drive electrode, the first drive electrode surface of the first stator and the second drive electrode surface of the second stator, And a partition plate arranged to separate the two electret films between the first electret film and the second electret film.

  According to the present invention, generation of stray light can be suppressed by reducing the distance between the two sliders.

  First, the driving principle of the shutter mechanism in the shutter device according to the present invention will be described with reference to FIGS.

  The shutter mechanism basically includes a stator 1 and a mover 2, and the mover 2 is configured to be movable in the left-right direction with respect to the stator 1. The stator 1 is provided with an opening 3 for guiding a light image from a subject to an image sensor (not shown), and a plurality of strip-like drive electrodes 4 are arranged in parallel with each other at a predetermined interval. ing. The mover 2 is a light-shielding member and includes a plurality of permanent-polarized derivatives (hereinafter referred to as electrets), which will be described later.

  When a frequency voltage is applied to the drive electrode 4 in such a configuration, an attractive force or a repulsive force is generated between the drive electrode 4 and the above-described electret, and as a result, the mover 2 moves relative to the stator 1. To do.

  Accordingly, if the movable element 2 is movable so as to open or shield the opening 3 of the stator 1, a shutter mechanism can be configured thereby. (1) in FIG. 1 shows a state in which the shutter is open, and (2) in FIG. 1 shows a state in which the shutter is closed.

  The opening 3 is not necessarily required for the stator 1. The stator 1 is used as a transmissive member, and a region where the drive electrode 4 is not provided, that is, a transmissive region is formed as shown in FIG. You may do it. Hereinafter, this is referred to as an opening for convenience. Further, the shutter mechanism according to this configuration is referred to as an “electret shutter”.

  The right side of FIG. 2 schematically shows a cross section of the electret shutter. A voltage signal line from the drive circuit 10 is connected to each drive electrode 4 arranged on the stator 1. A four-phase voltage signal is applied to the voltage signal line. Therefore, the same voltage signal is applied to the drive electrodes 4 every four lines. In FIG. 2, the voltage signals are distinguished by attaching the symbols A, B, C, and D to the drive electrode 4.

  The mover 2 is provided with a plurality of permanent-polarized derivatives (electrets) 5 on the surface facing the stator 1.

  In addition, this figure is a schematic diagram to the last, and the number and arrangement interval of electrodes and electret parts in an actual electret shutter are the size of the shutter mechanism, the area of the opening, the polarity of the electret part, the arrangement form, and the shutter mechanism. It is appropriately determined depending on various factors such as required drive resolution and maximum shutter speed. In addition, this electret shutter is a type in which electret portions having positive and negative polarities are alternately arranged, but can be realized with only one of the polarities.

  The left side of FIG. 2 shows the configuration of the drive circuit 10 that generates a voltage signal to be applied to the electret shutter. The rectangular wave train (drive pulse signal) generated by the pulse generation circuit 12 is supplied to the booster circuit 14 and the phase shifter 15. The booster circuit 14 boosts the input rectangular wave train to about 100 V, branches it into voltage signals having two polarities, and supplies them to the drive electrodes A and C.

  On the other hand, the rectangular wave train input to the phase shifter 15 has a waveform delayed by 90 °, and is then input to the booster circuit 14 to form two rectangular wave trains similar to those described above, and supplied to the drive electrodes B and D. Is done.

  FIG. 3 shows a voltage signal sequence created by the drive circuit 10 and applied to the drive electrode 4. As for the voltage state of the voltage electrode 4, the four states t1 to t4 change repeatedly corresponding to the passage of time.

  FIG. 4 is a diagram for explaining the operation of the electret shutter.

  (1) in FIG. 4 shows the voltage state of the electret and the drive electrode immediately after switching to t1. The electret 5 a receives a repulsive force from the drive electrode A and receives an attractive force from the drive electrode B. The electret 5 b receives a repulsive force from the drive electrode C and receives a suction force from the drive electrode D. For this reason, the movable element 2 receives a force in the right direction in the figure and moves by one drive electrode pitch d.

  (2) in FIG. 4 shows the voltage state of the electret and the drive electrode immediately after switching to t2. The electret 5 a receives a repulsive force from the drive electrode B and receives an attractive force from the drive electrode C. The electret 5 b receives a repulsive force from the drive electrode D and receives a suction force from the other drive electrode A. For this reason, the movable element 2 receives a force in the right direction in the figure and moves by one drive electrode pitch d.

  (3) in FIG. 4 shows the state of the electret and drive electrode voltage immediately after switching to t3, and (4) in FIG. 4 shows the state of the electret and drive electrode voltage immediately after switching to t4. Show. Similar to the above-described operation, the moving element 2 moves by one drive electrode pitch d. Then, by repeating this operation, the movable element 2 moves to the right in the figure. In order to move the movable element 2 in the left direction in the figure, the polarity of the voltage applied to the drive electrode 4 may be switched in reverse.

[First Embodiment]
FIG. 5 is a perspective view illustrating a configuration of an imaging module using the shutter device according to the first embodiment of the present invention, and FIG. 6 is a cross-sectional view of the imaging module.

  The imaging module includes a shutter unit 21 and an imaging unit 22.

  The shutter unit 21 is a focal plane shutter having a light-shielding curtain (front curtain) 24a and a light-shielding curtain (rear curtain) 24b that run independently. A partition plate 25 made of thin glass or the like is provided at the center of the shutter unit 21, and a light-shielding curtain 24 a provided with the above-described electret 5 (not shown) on each side (both sides) of the partition plate 25. , 24b are disposed. Further, on the outer side, there are disposed stators 1a and 1b provided with drive electrodes 4a and 4b and openings (or transmission parts) so as to sandwich the light shielding curtains 24a and 24b. In addition, spacers 31 to 34 having elasticity are provided between the partition plate 25 and the stators 1a and 1b, respectively.

  Thus, since the two stators 1a and 1b on which the drive electrodes 4a and 4b are formed face each other so that the drive electrodes 4a and 4b face each other, and the partition plate 25 is disposed between them, The distance between the two light-shielding curtains 24a and 24b can be shortened and can be made less susceptible to stray light. And since the spacers 31-34 are comprised with the elastic member, even if it thins the thin glass which is the partition plate 25 considerably thinly, it can prevent damaging by an impact.

  Here, the stators 1a and 1b use glass or the like as a substrate, drive electrodes 4a and 4b are formed on the surfaces thereof, and an insulating film is provided on the drive electrodes 4a and 4b. On the other hand, the light-shielding curtains 24a and 24b use polyimide or Teflon (registered trademark) as a base material, and a plurality of electrets are formed on one surface by a corona discharge method (electretized). In the present embodiment, electret portions having positive and negative polarities are alternately arranged in parallel with the drive electrodes 4a and 4b.

  Note that the shape of the shutter unit 21 of the present embodiment is as follows. The thicknesses of the stators 1a and 1b are 200 to 1000 μm. This is to reduce the thickness of the stators 1a and 1b and maintain the strength. And the thickness of the light-shielding curtains 24a and 24b is 10-25 micrometers. The height of the spacers 31 to 34 needs to be 1.3 to 1.5 times the thickness of the light shielding curtains 24a and 24b. Accordingly, the height of the spacers 31 to 34 is required to be 25 to 40 μm. Furthermore, the thickness of the partition plate 25 is desirably 70 to 100 μm. This is because if the thickness is too thin, the driving voltages of the stators 1a and 1b interfere with each other, and the movement of the light shielding curtains 24a and 24b is disturbed.

  The imaging unit 22 is configured by accommodating and fixing an imaging element 27 and a signal line 28 in a storage container 26 and covering the subject side of the storage container 26 with a cover glass 29 having an opening (transmission part).

  Note that, in the explanatory diagram of the present embodiment, for the sake of explanation, the interval between the imaging surface of the imaging device 27 and the cover glass 29 is sufficient, but this is the minimum from the viewpoint of shutter efficiency. It is desirable to be.

  Since the present imaging module uses the electret shutter to form the shutter unit 21, the thickness thereof can be greatly reduced as compared with the conventional shutter unit, and the thickness can be reduced.

  In addition, since the electret shutter does not use the charges induced in the light shielding curtains 24a and 24b but uses the charges that are permanently polarized in the electret, it is possible to shorten the rise time and speed up the shutter operation. it can.

  In addition, since the electret charge amount can be arbitrarily given, an optimum charge amount that maximizes the driving force can be given, and an extremely large driving force can be obtained. Accordingly, it is possible to configure an optimal shutter unit 21 corresponding to the size of the imaging module.

  Further, the light shielding curtains 24a and 24b are lightweight because a resin material can be used as a raw material. As described above, the light shielding curtains 24a and 24b can be formed of a thin film of 10 to 25 μm. Therefore, the amount of power required for the operation is small, and a quiet operation can be realized.

  In the shutter unit 21 according to the present embodiment, the method of driving the electret film is adopted. However, as described in Patent Document 1, a method of inducing charges in the high resistance may be adopted. .

  FIG. 7 is a diagram for explaining the operation of the light shielding curtain (front curtain) 24a and the light shielding curtain (rear curtain) 24b.

  In the initial state shown in FIG. 7 (1), the exposure aperture (light flux passage region) is fully closed. That is, the front curtain 24a covers the entire exposure aperture, and completely blocks the image pickup unit 22 from subject light. Next, as shown in FIG. 7 (2), the leading curtain 24a is driven in the direction of the arrow in the drawing in response to the start instruction of the photographing operation, and the exposure opening is fully opened, so that the subject light is guided to the imaging unit 22. It is burned. Then, when a predetermined time has elapsed, as shown in (3) of FIG. 7, the rear curtain 24b is driven in the direction of the arrow in the figure to shield the exposure opening. Thereafter, the front curtain 24a and the rear curtain 24b return to the initial state shown in (1) of FIG. 7, and wait for the next photographing operation.

  FIG. 8 is a block diagram showing a system configuration of a camera using the shutter device according to the first embodiment of the present invention.

  This camera system records a body unit 100 as a camera body, an accessory device (hereinafter abbreviated as “accessory”), for example, a lens unit (that is, a lens barrel) 112 as an interchangeable lens, and captured image data. A recording medium 139 to be stored, an external strobe unit 80, and the like.

  The lens unit 112 can be detachably attached via a lens mount (not shown) provided on the front surface of the body unit 100.

  The recording medium 139 is an external recording medium such as various memory cards or an external HDD, and is mounted so as to be communicable with the camera body via the communication connector 135 and exchangeable.

  The strobe unit 180 includes a flash light emitting unit 181, a DC / DC converter 182, a strobe control microcomputer 183, and a battery 184, and can be attached to the camera body via a strobe communication connector 185.

  The lens unit 112 is controlled by a lens control microcomputer (hereinafter referred to as “Lucom”) 105. The body unit 100 is controlled by a body control microcomputer (hereinafter referred to as “Bucom”) 150. The Lucom 105 and Bucom 150 are electrically connected to each other via the communication connector 106 when they are combined. As a camera system, the Lucom 105 is operated in cooperation with the Bucom 150 in a dependent manner.

  In the lens unit 112, photographing lenses 112a and 112b and a diaphragm 103 are provided. The taking lens 112a is driven by a DC motor (not shown) in the lens driving mechanism 102. The diaphragm 103 is driven by a stepping motor (not shown) in the diaphragm drive mechanism 104. The Lucom 105 controls each of these motors in accordance with a command from the Bucom 150.

  The following structural members are arranged in the body unit 100 as shown in the figure. For example, a single-lens reflex system component (penta prism 113a, quick return mirror 113b, eyepiece lens 113c, sub-mirror 113d) as an optical system, the imaging module 20, and a reflected light beam from the sub-mirror 113d are automatically measured. For this purpose, an AF sensor unit 130a is provided. The imaging module 20 includes a focus plane shutter unit 21 on the optical axis and an imaging unit 22 that houses a CCD for photoelectrically converting a subject image that has passed through the optical system.

  Further, the AF sensor driving circuit 130b for driving and controlling the AF sensor unit 130a, the mirror driving mechanism 118 for driving and controlling the quick return mirror 113b, and the movement of the front curtain 24a and the rear curtain 24b of the shutter unit 21 are controlled. A shutter drive control circuit 148 and a photometric circuit 132 that performs photometric processing based on the light flux from the pentaprism 113a are provided.

  The shutter drive control circuit 148 exchanges a signal for controlling the opening / closing operation of the shutter and a signal for synchronizing with the strobe with the Bucom 150.

  The camera system is also provided with a CCD interface circuit 134 connected to the imaging unit 22, a liquid crystal monitor 136, an SDRAM 138 provided as a storage area, a recording medium 139, and an image processing controller 140 that performs image processing. The electronic recording display function can be provided together with the electronic imaging function.

  The Bucom 150 is provided with an operation display LCD 157 for notifying the user of the operation state of the camera by display output, and a camera operation SW 152. The camera operation SW 152 is a switch group including operation buttons necessary for operating the camera, such as a release SW, a mode change SW, and a power SW. Further, a battery 154 as a power source and a power circuit 153 for converting the voltage of the power source into a voltage required for each circuit unit of the camera system and supplying the same are provided.

  Each part of the camera system configured as described above operates as follows.

  The mirror driving mechanism 118 is a mechanism for driving the quick return mirror 113b to the UP position and the DOWN position. When the quick return mirror 113b is at the DOWN position, the light flux from the photographing lenses 112a and 112b is the AF sensor unit 130a. Is divided and led to the pentaprism 113a side.

  The output from the AF sensor in the AF sensor unit 130a is transmitted to the Bucom 50 via the AF sensor driving circuit 130b, and a known distance measurement process is performed.

  The eyepiece 113c adjacent to the pentaprism 113a allows the user to see the subject, and part of the light beam that has passed through the pentaprism 113a is guided to a photosensor (not shown) in the photometry circuit 132, where it is detected. A well-known photometric process is performed based on the light quantity.

  The shutter drive control circuit 148 receives a signal for controlling the driving of the shutter from the Bucom 150, controls the shutter unit 21 based on the signal, and outputs a strobe tuning signal for causing the Bucom 150 to emit a strobe at a predetermined timing. Output. The Bucom 150 outputs a light emission command signal to the strobe unit 80 by communication based on the strobe tuning signal.

  The image processing controller 140 controls the CCD interface circuit 134 in accordance with an instruction from the Bucom 150 to capture image data from the imaging unit 22. The image data is converted into a video signal by the image processing controller 140 and output and displayed on the liquid crystal monitor 136. The user can confirm the captured image from the display image on the liquid crystal monitor 136.

  The SDRAM 138 is a memory for temporarily storing image data, and is used as a work area when image data is converted. The image data is set to be stored in the recording medium 139 after being converted into JPEG data.

  The shutter device according to the first embodiment of the present invention includes the shutter unit 21 and the shutter drive control circuit 148 shown in FIG.

  FIG. 9 is a configuration diagram showing signal connection between the shutter drive control circuit 148 and the shutter unit 21. The shutter unit 21 is provided with the front curtain 24a and the rear curtain 24b as described above, and two drive circuits having the configuration shown in FIG. 2 are provided to drive the respective light shielding curtains.

  The pulse generation circuit 12 drives the front curtain 24a and the rear curtain 24b based on the opening / closing control signal from the Bucom 150, and controls the full opening / closing operation of the exposure opening shown in FIG. When a reset signal is received from the Bucom 150, the front curtain 24a and the rear curtain 24b are driven to the initial state. Further, the pulse generation circuit 12 outputs a strobe tuning signal to the Bucom 150 at a predetermined timing.

  Subsequently, an imaging control method using the shutter device according to the first embodiment will be described.

  FIG. 10 is a flowchart showing a schematic photographing operation procedure of the Bucom 150. This operation shows an operation procedure from the release operation to image data generation in the processing procedure of the electronic camera.

  When the user presses the release button one step, this process starts. First, photometric processing is executed (S01). That is, the luminance information of the subject measured by the photometry circuit 132 is acquired. Then, an exposure amount calculation is executed based on the luminance information, and an appropriate aperture value (AV: aperture value) and shutter speed (TV: time value) are calculated (S02).

  Next, AF processing is executed (S03). The light flux from the subject is received by the AF sensor unit 130a via the quick return mirror 113b and the sub mirror 113d, and the deviation amount of the received subject image is output to the Bucom 150 via the AF sensor drive circuit 130b. The Bucom 150 calculates a lens shift amount from the shift amount of the subject image, and transmits the calculated value to the Lucom 105 via the communication connector 106. The Lucom 105 adjusts the focus by moving the photographing lens 112a via the lens driving mechanism 102 based on the amount of lens displacement.

  It is checked whether the release button is further pressed (two steps) with the focus adjusted (S04).

  If the release button has not been pressed down by two steps (No in S04) and the release button is in the state of pressing down by one step (S05 Yes), the process waits until the release button is pressed down by two steps. However, if the release button has not been pressed down by two steps (S04 No) and the release button has not been pressed down by one step (S05 No), it is determined that the user has stopped the shooting operation and the process is terminated. To do.

  When the release button is pressed down two steps (S04 Yes), the photographing operation is continued and the narrowing drive is executed (S06). That is, the Bucom 150 transmits the AV value to the Lucom 105 via the communication connector 106. The Lucom 105 controls the diaphragm 103 via the diaphragm driving mechanism 104 based on the sent AV value.

  Next, mirror-up driving is executed (S07). That is, the quick return mirror 113b is flipped up via the mirror driving mechanism 118 to secure the photographing optical path. Thereafter, an instruction is output to start the imaging operation to the image sensor interface circuit 134 (S08). The imaging element interface circuit 134 operates the imaging element 27 of the imaging unit 22 based on this instruction.

  After the above operation, the Bucom 150 executes a shutter control operation. The shutter control operation will be described with reference to the shutter control time chart for full-open exposure shown in FIG.

  The Bucom 150 outputs a shutter open signal to the shutter drive control circuit 148 (S09). That is, the signal level of the open / close control signal in FIG. 11 is made active. In response to this, the pulse generation circuit 12 of the shutter drive control circuit 148 starts outputting the front curtain drive pulse in order to drive the front curtain 24a. Corresponding to the number of pulses of the front curtain drive pulse, the front curtain 24a is driven in the opening direction from the fully closed position of the exposure opening as shown in the front curtain opening waveform of FIG. Thereafter, a timer for seconds is started (S10).

  Next, the Bucom 150 checks whether or not the exposure time has elapsed (S11).

  If the exposure time has not elapsed (No in S11), it is checked whether or not the strobe tuning signal shown in FIG. 11 is output from the shutter drive control circuit 148 (S12), and waits until the strobe tuning signal is output (S12). No, S11). The strobe tuning signal is output from the shutter drive control circuit 148 at the timing when the leading curtain 24a reaches a position where the exposure opening is fully opened.

  As described above, the front curtain 24a (and the rear curtain 24b) configured using the electret is extremely light, and therefore, the front curtain 24a can be driven with high accuracy and high speed by the front curtain drive pulse. Therefore, it is not necessary to detect whether or not the exposure opening is fully opened by using other detection means, and it can be determined by counting the number of front curtain drive pulses.

  Therefore, as shown in FIG. 11, the shutter drive control circuit 148 outputs a strobe tuning signal (rectangular signal) to the Bucom 150 at a timing when a predetermined number (m) of the first curtain drive pulse is output.

  When it is detected that the strobe tuning signal is activated, the Bucom 150 outputs a light emission control signal that instructs the strobe unit 180 to emit light (S14). If a light emission control signal has already been output, control is performed so that the light emission control signal is not output again (S13).

  If the exposure time has elapsed (S11 Yes), the Bucom 150 outputs a shutter close signal (S15). That is, the signal level of the open / close control signal is made non-active. In response to this, the pulse generation circuit 12 of the shutter drive control circuit 148 starts outputting the rear curtain drive pulse for driving the rear curtain 24b. According to the number of rear curtain drive pulses, the rear curtain 24b is driven from the fully open position of the exposure opening toward the fully closed position as shown in the rear curtain opening waveform of FIG.

  Next, the Bucom 150 outputs an instruction to the imaging element interface circuit 134 to stop the imaging operation (S16). The imaging element interface circuit 134 stops the imaging operation of the imaging element 27 of the imaging unit 22 based on this instruction.

  Further, the Bucom 150 outputs a reset signal to the shutter drive control circuit 148 (S17). In response to this, the pulse generation circuit 12 of the shutter drive control circuit 148 drives the front curtain 24a and the rear curtain 24b to the initial positions.

  After the shutter control operations from step S09 to step S17 are completed, the image processing controller 140 is instructed to execute image data processing (S18). The image processing controller 140 AD-converts a signal from the image sensor interface circuit 134 to generate image data, processes the image data, and records it on the recording medium 139 via the communication connector 135.

  The Bucom 150 then lowers the quick return mirror 113b via the mirror drive mechanism 118 (S19), and instructs the Lucom 105 to fully open the aperture 103 via the aperture drive mechanism 104 (S20). Then, the imaging operation is terminated.

  FIG. 12 is a shutter control time chart at the time of slit exposure.

  When the brightness of the subject is high, the exposure time may elapse before the front curtain 24a is fully opened. At this time, the shutter drive control circuit 148 outputs the trailing curtain drive pulse without outputting the strobe tuning signal. In this case, the exposure opening is not fully opened, and the slit opening formed by the front curtain 24a and the rear curtain 24b moves on the exposure opening. The imaging operation at the time of slit exposure is the same as the flow shown in FIG.

  Since the shutter device according to the embodiment described above is configured using the electret shutter, the light-shielding curtain can be controlled at a higher speed and with higher accuracy than a shutter device using a conventional stepping motor.

  In addition, since it is not necessary to use a stepping motor for driving the light-shielding curtain, the shutter device can be reduced in weight and further reduced in thickness. Therefore, it is possible to reduce the size and weight of a camera incorporating this shutter device.

  In addition, since this shutter device has low power consumption, it can save energy and resources.

  In addition, based on the above-mentioned embodiment, this invention can be expressed as follows.

(1) A first electrode substrate on which drive electrodes are formed, a second electrode substrate on which drive electrodes are formed, and a thin partition plate,
The first surface of the partition plate and the first electrode via an elastic member formed on the outer periphery of the first electrode substrate with the first surface of the partition plate facing the drive electrode of the first electrode substrate The surface on which the drive electrodes of the substrate are formed is bonded;
The other surface of the partition plate and the drive electrode of the second electrode substrate face each other, and the other surface of the partition plate and the second electrode substrate are interposed via a spacer member formed on the outer periphery of the second electrode substrate. The surface on which the drive electrode is formed is bonded;
A predetermined region of the first electrode substrate, the second electrode substrate and the partition plate is an opening or a transparent portion;
In the gap between the first electrode substrate and the partition plate, a first electret film having a band-shaped charging boundary region arranged at a predetermined pitch in a portion facing the first drive electrode;
In the gap between the second electrode substrate and the partition plate, a second electret film having a band-shaped charging boundary region arranged at a predetermined pitch in a portion facing the second drive electrode; and
A light shielding part is formed in a predetermined part of the first electret film and the second electret film;
A predetermined voltage pattern is applied to the driving electrode of the first electrode substrate, and the first electret film is displaced by applying an electrostatic force between the first electret film and the driving electrode of the first electrode substrate. Having means for
A predetermined voltage pattern is applied to the drive electrode of the second electrode substrate, and the second electret film is displaced by applying an electrostatic force between the second electret film and the drive electrode of the second electrode substrate. A shutter device for a camera comprising means for

  (2) The shutter device according to (1), wherein the spacer member is an elastic member.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

The figure which shows the shutter mechanism of the shutter apparatus which concerns on this invention. The figure which shows the basic composition of an electret shutter. The figure which shows the voltage signal sequence applied to a drive electrode. The figure explaining operation | movement of an electret shutter. 1 is a perspective view illustrating a configuration of an imaging module of a shutter device according to a first embodiment of the present invention. Sectional drawing of the imaging module of 1st Embodiment which concerns on this invention. The figure explaining operation | movement of a light-shielding curtain. 1 is a block diagram showing a system configuration of a camera using a shutter device according to a first embodiment of the present invention. The block diagram which shows the signal connection of a shutter drive control circuit and a shutter unit. The flowchart which shows the general | schematic imaging operation procedure of the microcomputer for body control. The figure which shows the shutter control time chart at the time of full open exposure. The figure which shows the shutter control time chart at the time of slit exposure.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Stator, 2 ... Moving element, 3 ... Opening part (transmission part), 4 ... Drive electrode, 5 ... Electret, 10 ... Drive circuit, 12 ... Pulse generation circuit, 14 ... Booster circuit, 20 ... Imaging module, 21 ... Shutter unit, 22 ... Imaging unit, 24 ... Light-shielding curtain, 25 ... Partition plate, 27 ... Imaging element, 31 ... Spacer.

Claims (4)

In a shutter device using an electret film as a shutter curtain,
A first stator having a light beam passage region and provided with a first drive electrode for driving the electret film;
A first electret film that is driven by the first drive electrode and travels on a surface provided with the first drive electrode;
A second stator having a light beam passage region and provided with a second drive electrode so as to face the first drive electrode;
A second electret film that is driven by the second drive electrode and travels on the surface on which the second drive electrode is provided;
Between the first drive electrode surface of the first stator and the second drive electrode surface of the second stator, and between the first electret film and the second electret film A partition plate that is disposed so as to separate the two electret films between them, and has a light flux passage region;
A shutter device characterized by comprising: In a shutter device using an electret film as a shutter curtain,
A first stator having a light beam passage region and having a first drive electrode on one surface for driving the electret film;
A first electret film that travels on a surface provided with the first drive electrode;
A partition plate arranged to sandwich the first electret film between one surface and the first stator;
A second electret film that travels on the other surface side of the partition plate;
A shutter device comprising: a second stator disposed so as to sandwich the second electret film between the surface on which the second drive electrode is provided and the partition plate.   The spacer member which has elasticity was provided between the said 1st stator and the said partition plate, and between the said 2nd stator and the said partition plate, The Claim 1 or 2 characterized by the above-mentioned. Shutter device. In a drive device using an electret film as a slider,
A first stator provided with a first drive electrode for driving the electret film;
A first electret film that is driven by the first drive electrode and travels on a surface provided with the first drive electrode;
A second stator provided with a second drive electrode for driving the electret film so as to face the first drive electrode;
Between the first drive electrode surface of the first stator and the second drive electrode surface of the second stator, and between the first electret film and the second electret film A partition plate arranged to separate the two electret films between,
A drive device characterized by comprising:

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