JP2005331830A - Electrostatic shutter apparatus and digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized electrostatic shutter apparatus which can be actually loaded to a camera or the like, regarding a shutter apparatus using the principle of an electrostatic actuator, and to provide a digital camera. <P>SOLUTION: The shutter unit 21 of an imaging module is provided with a front curtain 25a and a rear curtain 25b separately equipped with an electlet. Driving electrodes 28a and 28b and stators 29a and 29b with an opening part separately formed are arranged on the side facing the respective electlets 26a and 26b. Besides, a protecting member 32 with an opening part 31 formed is fixed on the object side of the shutter unit 21 so as to cover the front side of the shutter unit 21. An optical filter 37 constituted of an infrared cut-off filter or a low-pass filter is attached to the opening part 31 formed in the protecting member 32. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a digital camera and an electrostatic shutter device that can be used for the digital camera and the like.

  Conventionally, as a shutter device of a camera, there are known a method of driving a shutter blade by a step motor and a method of opening and closing the shutter blade using a spring force. In these systems, a complicated structure is required to transmit the driving force of the driving device that drives the shutter blades to the shutter blades.

In view of this, there is known a shutter device having a very simple structure that is lighter and lower in cost by driving a shutter curtain formed of a light shielding film using the principle of an electrostatic actuator (see, for example, Patent Document 1). ).
Japanese Patent Laid-Open No. 8-220592

  By the way, the above-mentioned Patent Document 1 does not specifically disclose a technique for mounting the shutter mechanism in an actual camera.

  Therefore, in consideration of actually mounting a shutter device (hereinafter abbreviated as an electrostatic shutter) using the principle of this type of electrostatic actuator on a camera, the drive electrode substrate and the cover glass are interposed via a spacer. It is possible to consider a structure in which the moving space of the shutter curtain is secured by stacking.

  However, if a plurality of substrates or cover glasses are laminated, the entire shutter device becomes thick. In addition, in the case of a digital camera, since it is necessary to insert optical components such as an infrared cut filter and a low-pass filter in the photographing optical path, the thickness of the camera body in the optical axis direction may increase.

  Accordingly, the present invention has been made in view of the above circumstances, and provides a small electrostatic shutter device and a digital camera that can be actually mounted on a camera or the like in a shutter device using the principle of an electrostatic actuator. For the purpose.

  That is, the invention according to claim 1 is generated when a stator having an opening through which a subject light flux passes, a plurality of electrode portions provided on the stator, and a frequency voltage applied to the electrode portions. And a movable element that can move between a position where the opening is shielded and a position where the opening is opened, and an opening through which the subject light beam passes, and the movable element is sandwiched between the stationary element and the stator. In the electrostatic shutter device including the protective member arranged, an optical element that changes an optical characteristic of the subject light beam is embedded in the opening of the protective member.

  According to a second aspect of the present invention, in the first aspect of the present invention, the optical element is an infrared cut filter or a low-pass filter.

  The invention according to claim 3 is the invention according to claim 1, wherein an optical element having characteristics different from those of the optical element embedded in the protective member is embedded in the opening of the stator. And

  The invention described in claim 4 is the invention described in claim 1, characterized in that the protective member is a glass plate, an acrylic plate, or a hard substrate.

  According to a fifth aspect of the present invention, there is provided a stator having an opening through which a subject luminous flux passes, a plurality of electrode portions provided on the stator, and a static voltage generated when a frequency voltage is applied to the electrode portions. Receiving electric power, it has a moving element that can move between a position where the opening is shielded and a position where the opening is opened, and a region through which the subject luminous flux passes, and is arranged so as to sandwich the moving element together with the stator. An electrostatic shutter device comprising a protective member, wherein an optical element having an infrared cut characteristic or a low-pass characteristic is formed in the region of the protective member.

  According to a sixth aspect of the present invention, there is provided an imaging device, a stator having an opening for guiding a subject light beam to the imaging device, a plurality of electrode parts provided on the stator, and a frequency applied to the electrode parts. A moving element that receives an electrostatic force generated when a voltage is applied, and is movable between a position where the opening is shielded and a position where the opening is opened; and an opening through which the subject luminous flux passes; And a protective member disposed so as to be sandwiched together with the stator, and an optical element for changing optical characteristics of the subject light beam is embedded in the opening of the protective member.

  The invention described in claim 7 is the invention described in claim 6, wherein the optical element is an infrared cut filter or a low-pass filter.

  The invention according to claim 8 is the invention according to claim 6, wherein an optical element having characteristics different from those of the optical element embedded in the protective member is embedded in the opening of the stator. And

  According to a ninth aspect of the present invention, there is provided an imaging device, a stator having an opening for guiding a subject light beam to the imaging device, a plurality of electrode parts provided on the stator, and a frequency applied to the electrode parts. A moving element that receives an electrostatic force generated when a voltage is applied, and is movable between a position where the opening is shielded and a position where the opening is opened; and a region through which the subject luminous flux passes; An electrostatic shutter device comprising a protective member disposed so as to be sandwiched together with a stator, wherein an optical element having an infrared cut characteristic or a low-pass characteristic is formed in the region of the protective member. To do.

  According to a tenth aspect of the present invention, there is provided a movable element that can move to a position that shields a subject light flux passage area, and a plurality of drive electrodes that have a subject light flux passage area and electrostatically drive the movable element. A stator provided, a protective member having a passage region for the subject light beam, and disposed so as to sandwich the movable member together with the stator; and the passage of the subject light beam of at least one of the stator and the protective member And an optical element that is attached to the region and changes an optical characteristic of the subject luminous flux.

  The invention described in claim 11 is the invention described in claim 10, wherein the optical element is an infrared cut filter or a low-pass filter.

  According to a twelfth aspect of the present invention, there is provided the optical element according to the tenth aspect, wherein an optical element having characteristics different from those of the optical element mounted on the protective member is provided in the passage region of the subject luminous flux of the stator. It is mounted.

  The invention described in claim 13 is the invention described in claim 10, wherein the protective member is a glass plate, an acrylic plate, or a hard substrate.

  According to a fourteenth aspect of the present invention, in the tenth aspect, the protective member and the optical element are tapered to reduce the thickness of the protective member and the optical element toward the joint portion of the protective member and the optical element. It is provided.

  The invention described in claim 15 has an imaging device for imaging a subject, a mover that can be moved to a position that blocks an opening through which the subject luminous flux passes, and a passage area for the subject luminous flux. A stator provided with a plurality of driving electrodes for electrostatically driving the moving element, and an electrostatic shutter device disposed in front of the imaging element, and an opening through which the subject light flux passes. And a protection member disposed so as to sandwich the movable element together with the stator of the shutter device, and an optical member that is attached to at least one opening of the stator and the protection member to change the optical characteristics of the subject luminous flux. And an element.

  The invention described in claim 16 is the invention described in claim 15, characterized in that the optical element is an infrared cut filter or a low-pass filter.

  According to a seventeenth aspect of the present invention, in the invention according to the fourteenth aspect, an optical element having characteristics different from those of the optical element mounted on the protective member is mounted in the opening of the stator. It is characterized by that.

According to an eighteenth aspect of the present invention, in the fifteenth aspect of the invention, the protective member and the optical element are tapered so as to reduce the thickness toward the joint portion of the protective member and the optical element. It is provided.

  According to the present invention, it is possible to provide a small electrostatic shutter device and a digital camera that can be actually mounted on a camera or the like in a shutter device using the principle of an electrostatic actuator.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

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

  The shutter device basically includes a stator 1 and a mover 2, and the mover 2 is configured to be movable in the left-right direction in FIGS. 1A and 1B with respect to the stator 1. Has been. The stator 1 is provided with an opening 3 for guiding a light image from the subject to an image sensor (not shown). Further, a plurality of strip-like extended drive electrodes 4 are arranged in parallel at predetermined intervals on the stator 1 in a direction orthogonal to the moving direction of the moving element 2.

  The mover 2 includes a plurality of permanent-polarized extended derivatives (hereinafter referred to as electrets) 5 described later.

  In such a configuration, when a frequency voltage is applied to the drive electrode 4, an attractive force or a repulsive force is generated between the drive electrode 4 and the above-described electret. Move relative. Therefore, if the movable element 2 is movable so as to open or shield the opening 3 of the stator 1, a shutter device can be configured thereby.

  FIG. 1A shows a state where the shutter is open, and FIG. 1B shows a state where the shutter is closed. Note that the opening 3 is not necessarily required in the stator 1, and the region where the driving electrode 4 is not provided as shown in FIG. 1A using the stator 1 as a transmissive member, that is, a transmissive region. May be formed. Hereinafter, such a region through which the subject luminous flux passes is referred to as an opening for convenience. In addition, the shutter device according to this configuration is referred to as an electret shutter.

  FIG. 2 is a diagram schematically showing a cross section of such an electret shutter and a drive circuit for the electret shutter.

  In the electret shutter 7, voltage signal lines from the drive circuit 10 are connected to the drive electrodes 4 arranged in parallel with the stator 1. A four-phase voltage signal is applied to these voltage signal lines. Therefore, the same voltage signal is applied to each of the four drive electrodes 4. 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.

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

  The left side of FIG. 2 shows the configuration of the drive circuit 10 for generating a voltage signal applied to the electret shutter 7 together with the configuration of the electret shutter 7 described above.

  The rectangular wave train (drive pulse signal) generated by the pulse generation circuit 12 is supplied to the phase shifter 13 and the booster circuit 14. In the booster circuit 14, the input rectangular wave train is boosted to about 100 V, is branched into voltage signals having two polarities, and is supplied to the drive electrodes 4 A and 4 C. On the other hand, the rectangular wave train input to the phase shifter 13 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 is applied to the drive electrodes 4B and 4D. Supplied.

  FIG. 3 is a timing chart showing an example of a voltage signal sequence created by the drive circuit 10 and applied to the drive electrodes 4A to 4D. Among these, FIG. 3A is a drive electrode 4A, FIG. 3B is a drive electrode 4B, FIG. 3C is a drive electrode 4C, and FIG. 3D is a timing chart of the drive electrode 4D.

  The voltage states of the drive electrodes 4A to 4D are such that the four states from time t1 to t4 change repeatedly as time elapses.

  4A to 4D are views for explaining the operation of the electret shutter 7 described above. 4 (a) to 4 (d), the right direction in the drawing is the traveling direction of the electret, the positive (positive) electret 5a on the rear side (left side), and the negative (minus) on the front side (right side). The electrets 5b are arranged.

  FIG. 4A shows the voltage state (polarity) of the electret and the drive electrode 4 immediately after switching to the time t1 shown in FIG.

  In this state, the positive electret 5a receives a repulsive force from the drive electrode A (positive electrode) and receives an attractive force from the drive electrode B (negative electrode). The negative electret 5b receives a repulsive force from the drive electrode C (negative electrode) and receives an attractive force from the drive electrode D (positive electrode). For this reason, the movable element 2 receives a force in the right direction in FIG. 4A and moves to the right by one drive electrode pitch d.

  FIG. 4B shows the voltage state of the electret and the drive electrode immediately after switching at time t2.

  In this state, the electret 5a receives a repulsive force from the drive electrode B (positive electrode) and receives an attractive force from the drive electrode C (negative electrode). The electret 5b receives a repulsive force from the drive electrode D (negative electrode) and receives an attractive force from the drive electrode A (positive electrode). Therefore, the mover 2 receives a force in the right direction in FIG. 4B and moves by one drive electrode pitch d.

  Similarly, FIG. 4C shows the voltage state of the electret and the drive electrode immediately after switching at time t3.

  In this state, the electret 5a receives a repulsive force from the drive electrode C (positive electrode) and receives an attractive force from the drive electrode D (negative electrode). The electret 5b receives a repulsive force from the drive electrode A (negative electrode) and receives an attractive force from the drive electrode B (positive electrode). Therefore, the mover 2 receives a force in the right direction in FIG. 4C and moves by one drive electrode pitch d.

  Further, FIG. 4D shows the state of the electret and drive electrode voltages immediately after switching to time t4.

  In this state, the electret 5a receives a repulsive force from the drive electrode D (positive electrode) and receives an attractive force from the drive electrode A (negative electrode). The electret 5b receives a repulsive force from the drive electrode A (negative electrode) and receives an attractive force from the drive electrode C (positive electrode). For this reason, the moving element 2 receives a force in the right direction of FIG. 4D and moves by one drive electrode pitch d.

  As described above, the movable element 2 moves by one drive electrode pitch d, and this operation is repeated, so that the movable element 2 is changed as shown in FIGS. 4 (a) → (b) → (c) → (d). Move to the right (arrow F direction in the figure). In order to move the mover 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)
Next, a first embodiment of the present invention will be described.

  FIG. 5 is an assembly diagram illustrating a configuration of an imaging module to which the shutter device according to the first embodiment of the present invention is applied, and FIG. 6 illustrates a configuration in a state where the imaging module having the configuration of FIG. 5 is assembled. It is sectional drawing.

  The imaging module 20 includes a shutter unit 21 and an imaging unit 22. The shutter unit 21 is a focal plane shutter having a front curtain (shutter front curtain) 25a and a rear curtain (shutter rear curtain) 25b that run independently of each other. The front curtain 25a and the rear curtain 25b are provided with the above-described electret 5 (not shown). A stator 29a provided with a plurality of strip-like extended drive electrodes (electrode parts) 28a, 28b and openings (or transmission parts) 27a, 27b on the opposing surface side of each electret 5. 29b is disposed.

  The front curtain 25a and the rear curtain 25b are configured to be movable in the longitudinal direction of the stators 29a and 29b, respectively. The plurality of electrodes 28a, 28b are arranged in parallel at predetermined intervals on the stators 29a, 29b in a direction perpendicular to the moving direction of the front curtain 25a and the rear curtain 25b.

  Further, on the subject side (left side in FIGS. 5 and 6) of the shutter unit 21, a protective member 32 having an opening 31 is fixed so as to cover the front surface of the shutter unit 21 via spacers 33 to 36. It is installed. Here, the stators 29a and 29b are configured by using glass or the like as a substrate, drive electrodes 28a and 28b are formed on the surfaces thereof, and an insulating film (not shown) is further provided on the drive electrodes 28a and 28b. ing. By applying this insulating film, a short circuit between adjacent drive electrodes is prevented.

  On the other hand, the front curtain 25a and the rear curtain 25b are made of polyimide or Teflon (registered trademark) as a base material, and a metal such as aluminum is deposited thereon. Thereby, although it is not perfect, a certain amount of light-shielding property can be ensured. In the present embodiment, such a characteristic is referred to as semi-translucency. A plurality of electrets are formed by a corona discharge method on one surface of the base material (film film) used as the front curtain 25a and the rear curtain 25b, in this case, the surface facing the drive electrodes 28a and 28b. (This is called electretization.) In the present embodiment, electret portions having positive and negative polarities are alternately arranged (see, for example, electrets 5a and 5b in FIG. 4).

  Moreover, the said protection member 32 is comprised, for example by members, such as a mold, For example, the opening part 31 is formed in the center part as mentioned above. An optical filter 37 composed of an infrared cut filter or a low-pass filter is attached to the opening 31.

FIG. 7 is an enlarged view showing a joint portion between the protection member 32 and the optical filter 37. In this case, in FIG. 7, the left side is the subject side and the right side is the imaging unit 22 side. The joint between the protective member and the optical filter 37 is fixed by an adhesive 44 or the like. At this time, the surfaces of the protection member 32 and the optical filter 37 on the imaging unit 22 side are bonded so that the surface of the optical filter 37 is lower than the protection member 32 by d ₁ . In the vicinity of the joining surface of the protection member 32 and the optical filter 37, tapered portions 32a and 37a are formed, respectively.

  Thereby, when the front curtain 25a moves, there is no possibility of being caught by the joint portion between the protection member 32 and the optical filter 37. In addition, since the taper portions 32a and 37a are formed, even if the adhesive 44 protrudes from the joint portion, it does not become higher than the surface of the protective member 32 and the optical filter 37. Will not interfere.

  The imaging unit 22 is made of resin or the like, and accommodates and fixes the imaging element 40 and the signal line 41 in the storage container 39, and a cover having an opening (translucent part) on the subject side of the storage container 39. The glass 42 is covered.

  The openings provided in the cover glass 42 are provided at positions corresponding to the openings 27 a and 27 b of the stators 29 a and 29 b and the openings 31 provided in the protection member 32. As a result, the subject light captured through the optical filter 37 attached to the opening 31 is guided to the image sensor 40 which is a photoelectric conversion element, and the image of the subject is photoelectrically converted by the image sensor 40. .

  Thus, since this imaging module 20 comprises the shutter unit 21 using the electret shutter, the thickness can be significantly reduced compared with the conventional shutter unit, and it can reduce in thickness. it can.

  Further, in the case of the imaging module 20, the protection member 32 is formed of an inexpensive member, and the optical filter 37 is embedded only in a region through which the light beam actually passes. Therefore, the entire protection member is made of an infrared cut filter, a low-pass filter, or the like. There is an advantage that it can be manufactured at a lower cost compared to the case of using an expensive optical element.

  In addition, since the electret shutter does not use the charges induced in the front curtain 25a and the rear curtain 25b, but uses charges that are permanently polarized in the electret, the shutter rise time is shortened and the shutter operation is performed at high speed. Can be

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

  Furthermore, since the front curtain 25a and the rear curtain 25b can use a resin material as a raw material, they are lightweight. For example, the front curtain 25a and the rear curtain 25b can be formed of thin films of 10 to 20 μm. Therefore, the amount of power required for the operation is small, and a quiet operation can be realized.

  FIG. 8 is a diagram for explaining the operation of the front curtain 25a and the rear curtain 25b.

  FIG. 8A shows an initial state, and the exposure opening 27 is fully closed. That is, the entire exposure opening 27 is covered by the front curtain 25a, and the subject light is shielded from the imaging unit 22 (not shown).

Then, in response to the start instruction of the imaging operation, as shown in FIG. 8 (b), the exposure opening 27 leading curtain 25a is driven to the illustrated direction of arrow F ₁ is fully opened. As a result, the subject light is guided to the imaging unit 22 (not shown).

Then, when a predetermined time has elapsed, as shown in FIG. 8 (c), the exposure opening 27 by the rear curtain 25b is driven in the arrow F ₂ direction is shielded. Thereafter, the front curtain 25a and the rear curtain 25b return to the initial state shown in FIG. 8A, and wait for the next imaging operation.

  FIG. 9 is a block diagram showing an electrical system configuration of a camera having an electrostatic shutter device according to an embodiment of the present invention.

  In FIG. 9, this camera system records image data taken via a body unit 50, an accessory device such as a replaceable lens unit (that is, a lens barrel) 51, and a communication connector 56. A recording medium 52 and an external flash unit 53 are provided via a flash communication connector 57.

  The lens unit 51 can be detachably mounted via a lens mount (not shown) provided on the front surface of the body unit 50. The lens unit 51 includes photographing lenses 61a and 61b, a diaphragm 62, a lens driving mechanism 63, a diaphragm driving mechanism 64, and a lens control microcomputer (hereinafter abbreviated as Lμcom) 65. Yes.

  The photographing lenses 61a and 61b are driven in the optical axis direction by a DC motor (not shown) existing in the lens driving mechanism 63. The diaphragm 62 is driven by a stepping motor (not shown) existing in the diaphragm drive mechanism 64. The Lμcom 65 drives and controls each part in the lens unit 51 such as the lens driving mechanism 63 and the aperture driving mechanism 64. The Lμcom 65 is electrically connected to a body control microcomputer 85, which will be described later, via the communication connector 55, and is controlled in accordance with a command from the body control microcomputer 85.

  On the other hand, the body unit 50 is configured as follows.

  A light beam from a subject (not shown) that enters through the taking lenses 61 a and 61 b and the diaphragm 62 in the lens unit 51 is reflected by the quick return mirror 70, and enters the eyepiece lens 73 through the focusing screen 71 and the pentaprism 72. It reaches.

  The central portion of the quick return mirror 70 is a half mirror, and a part of the light beam is transmitted when the quick return mirror 70 is down (position shown). The transmitted light beam is reflected by the sub mirror 75 installed on the quick return mirror 70 and guided to the AF sensor unit 76 for automatic ranging. The sub mirror 75 is folded when the quick return mirror 70 is up.

  Behind the quick return mirror 70 are a focal plane type shutter unit 21 on the optical axis, and an imaging unit 22 containing an imaging device (CCD) 40 for photoelectrically converting a subject image that has passed through the optical system. The provided imaging module 20 is provided. Although not shown here, as described above, the front surface of the shutter unit 21 is provided with the protection member 32 to which the optical filter 37 is attached (see FIGS. 5 and 6). Further, although not shown, when the quick return mirror 70 is retracted from the optical path, the light flux that has passed through the photographing lenses 61a and 61b is imaged on the imaging element 40 (see FIGS. 5 and 8) in the imaging module 20.

  The body unit 50 also includes an image pickup device interface circuit 80 connected to the image pickup device 40 in the image pickup module 20, an SDRAM 82 provided as a storage area, a liquid crystal monitor 83, and a communication medium via the communication connector 56. 52 is connected to an image processing controller 81 for performing image processing. These are configured to provide an electronic recording display function together with an electronic imaging function.

  The recording medium 52 is an external recording medium such as various memory cards or an external hard disk drive (HDD), and is attached to the camera body 50 via the communication connector 56 so as to be exchangeable.

  The image processing controller 81 includes a communication connector 55, a photometry circuit 86, a mirror drive circuit 87, an AF sensor drive circuit 88, a shutter drive control circuit 90 as drive control means, a nonvolatile memory (EEPROM) 91, and the like. At the same time, it is connected to a body control microcomputer (hereinafter abbreviated as Bμcom) 85 for controlling each part in the body unit 50.

  The Bμcom 85 is connected with an operation display LCD 92 for notifying the photographer of the operation state of the camera by display output, a camera operation switch (SW) 93, and a battery 96 via a power supply circuit 95. . Further, a power control microcomputer (Pμcom) 97 for controlling the power supply circuit 95 is connected to the Bμcom 85. A power switch (SW) 98 is connected to the Pμcom 85.

  The Bμcom 85 and Lμcom 65 are electrically connected via the communication connector 55 when the lens unit 51 is mounted. As a digital camera, the Lμcom 65 is operated in cooperation with the Bμcom 85 in a dependent manner.

  The photometric circuit 86 is a circuit that performs photometric processing based on the light flux from the pentaprism 72. The mirror driving mechanism 87 is a mechanism for driving and controlling the quick return mirror 70, and the AF sensor driving circuit 88 is a circuit for driving and controlling the AF sensor unit 76. Further, the shutter drive control circuit 90 controls the movement of the front curtain 25a and the rear curtain 25b of the shutter unit 21 and transmits / receives a signal for controlling the opening / closing operation of the shutter and a signal synchronized with the strobe to / from the Bμcom 85. Do.

  The non-volatile memory 91 is a storage unit that stores predetermined control parameters necessary for camera control as other storage areas, and is provided so as to be accessible from the Bμcom 85.

  The operation display LCD 92 is for notifying the photographer of the operation state of the camera by display output. The camera operation switch 93 is a group of switches including operation buttons necessary for operating the camera, such as a release switch for instructing execution of a shooting operation, a mode change switch for switching between a shooting mode and an image display mode, and a power switch. Composed.

Further, the power supply circuit 95, a voltage V _E of the battery 96 as a power source, is provided to supply and converted into a voltage V _C of respective circuit units of the camera system needs. Then, the power supply circuit 95, a control signal P _com from the Pmyucom97, its on, off controlled.

  The strobe unit 53 includes a flash light emitting unit 101, a DC / DC converter 102, a strobe control microcomputer 103, and a battery 104. The strobe unit 53 can be mounted so as to be communicable with the body unit 50 via a strobe communication connector 57.

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

  First, the image processing controller 81 controls the image sensor interface circuit 80 in accordance with a command of Bμcom 85, and image data is captured from the image capture module 20. This image data is taken into the SDRAM 82 which is a temporary storage memory. The SDRAM 82 is used as a work area when image data is converted. The image data is set to be stored in the recording medium 52 after being converted into JPEG data.

  As described above, the mirror drive mechanism 87 is a mechanism for driving the quick return mirror 70 to the up (UP) position and the down (DOWN) position. When the quick return mirror 70 is in the down position by the mirror driving mechanism 87, the light beams from the photographing lenses 61a and 61b are divided and guided to the AF sensor unit 76 side and the pentaprism 72 side.

  The output from the AF sensor in the AF sensor unit 76 is transmitted to the Bμcom 85 via the AF sensor driving circuit 88, and a known distance measurement process is performed.

  On the other hand, from the eyepiece lens 73 adjacent to the pentaprism 72, the photographer can see the subject. A part of the light beam that has passed through the pentaprism 72 is guided to a photosensor (not shown) in the photometry circuit 86, and a well-known photometry process is performed based on the amount of light detected here.

  When the shutter drive control circuit 90 receives a signal for controlling the drive of the shutter from the Bμcom 85, the shutter unit 21 is controlled based on the signal. At the same time, the shutter drive control circuit 90 outputs a strobe tuning signal for causing the Bμcom 85 to emit a strobe at a predetermined timing. Based on this strobe tuning signal, the Bμcom 85 outputs a light emission command signal to the strobe unit 53 by communication.

  Further, when the mode change switch in the camera operation switch 93 described above is operated by the photographer to switch from the shooting mode to the image display mode, the image data stored in the recording medium 52 is read out, and the liquid crystal monitor 83 can be displayed. The image data read from the recording medium 52 is converted into a video signal by the image processing controller 81 and output and displayed on the liquid crystal monitor 83.

  By the way, whether the power switch 98 is off or on is monitored by Pμcom 97. Here, when the power switch 98 is switched from OFF to ON, an active signal is output from the Pμcom 97 and the operation of the power circuit 95 is started. Then, a necessary voltage is supplied from the power supply circuit 95 to each circuit unit of the camera system, and thereby the operation of the Bμcom 85 is also started.

  On the other hand, when the power switch 98 is turned off, a non-active signal is output from Pμcom 97 and the operation of the power circuit 95 is stopped. Thereby, the operation of each circuit unit of the camera system is also stopped.

Further, even during operation of the Bimyucom85, when the camera operation switch 93 is nothing is operated a certain time, the control signal P _off is outputted to Pμcom97 from Bimyucom85. Thereby, a non-active signal is output from Pμcom 97, the operation of the power supply circuit 95 is stopped, and the operation of each circuit unit of the camera system is also stopped.

  If the camera operation switch 93 is not operated and the power is turned off, the camera operation switch 93 is operated again, so that an active signal is output from the Pμcom 97 and the operation of the power supply circuit 95 is started. The operation of each circuit unit of the camera system is also started. This is because even if the camera operation switch 93 is not operated for a certain period of time, if the photographer operates the camera operation switch 93 again, the operation is started from the process of turning on the power switch 98. Because it will come.

  On the other hand, when the operation of the power supply circuit 95 is stopped by turning off the power supply switch 98, the operation of the power supply circuit is not started unless the power supply switch 98 is turned on again.

  The shutter device according to the present embodiment includes the shutter unit 21 and the shutter drive control circuit 90 shown in FIG.

  FIG. 10 is a configuration diagram showing signal connection between the shutter drive control circuit 90 and the shutter unit 21.

  As described above, the shutter unit 21 is provided with the front curtain 25a and the rear curtain 25b. In order to drive the respective curtains, the phase shifter 112a having the same configuration as that shown in FIG. Two systems of drive circuits 113a and 113b as drive means including 112b are provided. The pulse generation circuit 111 drives the front curtain 25a and the rear curtain 25b based on the open / close control signal from the Bμcom 85. As a result, the permanently polarized derivatives (electrets) 26a and 26b provided in the front curtain 25a and the rear curtain 25b are sequentially sucked by the A to D of the drive electrodes 28a and 28b, and the front curtain 25a and the rear curtain 25b are driven. Is done. In this way, the full opening / closing operation of the exposure opening 27 shown in FIG. 8 is controlled.

  When a reset signal is received from Bμcom 85, the leading curtain 25a and trailing curtain 25b are driven to the initial state. Further, the strobe tuning signal is output from the pulse generation circuit 111 to the Bμcom 85 at a predetermined timing.

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

  FIG. 11 is a flowchart showing a schematic photographing operation procedure of Bμcom85. This operation shows an operation procedure from a release operation to image data generation in the processing procedure of the camera system.

  When the photographer presses the release button in the camera operation switch 93 one step, this routine is started.

  First, in step S1, photometry processing is executed. That is, the luminance information of the subject measured by the photometric circuit 86 is acquired. Next, in step S2, an exposure amount calculation is executed based on the luminance information, and an appropriate aperture value (AV) and shutter speed (TV: time value) are calculated.

  In step S3, AF processing is executed. That is, the luminous flux from the subject is received by the AF sensor unit 76 via the quick return mirror 70 and the sub mirror 75. The deviation amount of the received subject image is output to the Bμcom 85 via the AF sensor driving circuit 88. In Bμcom 85, the lens driving amount is calculated from the amount of shift of the subject image, and the value is transmitted to Lμcom 65 in the lens unit 51 via the communication connector 55. In the Lμcom 65, the focus is adjusted by moving the photographing lens 61a via the lens driving mechanism 63 based on the lens driving amount.

  Here, in step S4, it is determined whether or not the release button is further pressed (two steps) with the focus adjusted (2nd release switch ON). If the release button has not been pressed down two steps, the process proceeds to step S5 to determine whether or not the release button has been pressed down one step. Here, when the release button is in the state of being pressed down by one step, the process proceeds to step S4 and waits until the release button is pressed down by two steps. However, if the release button has not been pressed down two steps and the release button has not been pressed down one step, it is determined that the photographer has stopped the shooting operation, and this routine ends.

  If the release button has been depressed in two steps in step S4, the photographing operation is continued, and the process proceeds to step S6 to perform narrowing driving. That is, the AV value is transmitted to the Lμcom 65 via the communication connector 55 by Bμcom85. In the Lμcom 65, the diaphragm 62 is controlled via the diaphragm driving mechanism 64 based on the sent AV value.

  Next, mirror up driving is executed in step S7. That is, the quick return mirror 70 is flipped up to the up position via the mirror drive mechanism 87, and the photographing optical path is secured. Thereafter, in step S8, an instruction is output from the Bμcom 85 so that the imaging operation is started with respect to the imaging element interface circuit 80. Then, the image sensor interface circuit 80 operates the image sensor 40 in the image pickup unit 22 based on this instruction.

  After the above operation, the shutter control operation is executed by the Bμcom 85. This shutter control operation will be described with reference to the flowchart of FIG. 11 and the shutter control time chart for full-open exposure shown in FIG.

  In step S 9, a shutter open signal is output from Bμcom 85 to the shutter drive control circuit 90. That is, the signal level of the open / close control signal shown in the time chart of FIG. 12 is activated. Next, in step S10, the pulse generation circuit 111 in the shutter drive control circuit 90 that has received this starts output of the front curtain drive pulse to drive the front curtain 25a. Corresponding to the number of pulses of the front curtain drive pulse, as shown in the front curtain opening waveform of FIG. 12, the front curtain 25a is driven in the opening direction from the fully closed position of the exposure opening.

  Next, in step S11, Bμcom 85 determines whether or not the exposure time has elapsed. If the exposure time has not elapsed, the process proceeds to step S12, and it is determined whether or not the strobe tuning signal shown in FIG. Here, it waits until the strobe tuning signal is output.

  The strobe tuning signal is output from the shutter drive control circuit 90 at the timing when the leading curtain 25a reaches the position where the exposure opening is fully opened. As described above, the front curtain 25a (and the rear curtain 25b) configured by using the electret is extremely light, so that the front curtain 25a can be driven with high accuracy and high speed by this front curtain drive pulse. is there. 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. 12, the shutter drive control circuit 90 outputs a strobe tuning signal (rectangular signal) to the Bμcom 85 at the timing when a predetermined number (m) of the front curtain drive pulses are output. If it is detected in step S12 that the strobe tuning signal has become active, the process proceeds to step S13, and whether or not a light emission control signal that instructs the strobe unit 53 to emit light is output from Bμcom 85. Is judged.

  If the light emission control signal has not been output yet, the process proceeds to step S14, the light emission control signal is output to the strobe unit 53, and then the process proceeds to step S11. On the other hand, if the light emission control signal has already been output, control is performed so that the light emission control signal is not output again, and the process proceeds to step S11.

  When the exposure time has elapsed in step S11, the process proceeds to step S15, and a shutter close signal is output from Bμcom 85. That is, the signal level of the open / close control signal is made non-active. In response to this, the pulse generation circuit 111 in the shutter drive control circuit 90 starts to output the rear curtain drive pulse for driving the rear curtain 25b. According to the number of rear curtain drive pulses, the rear curtain 25b 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, in step S16, an instruction to stop the imaging operation is output from Bμcom 85 to the imaging element interface circuit 80. Based on the instruction from the image sensor interface circuit 80, the imaging operation of the image sensor 40 in the imaging unit 22 is stopped.

  In step S <b> 17, a reset signal is output to the shutter drive control circuit 90. In response to this, the front curtain 25a and the rear curtain 25b are driven to the initial positions by the pulse generation circuit 111 in the shutter drive control circuit 90 (see FIG. 8A).

  Next, in step S18, the Bμcom 85 instructs the image processing controller 81 to execute image data processing. In the image processing controller 81, first, the stored charge of the image sensor 40 is read via the image sensor interface circuit 80. Then, the signal is A / D converted to generate image data. Then, the image data is processed and recorded on the recording medium 52 from the image processing controller 81 via the communication connector 56.

  Further, in step S19, the quick return mirror 70 is driven from the Bμcom 85 to the down position via the mirror drive mechanism 87. In step S20, the Lμcom 65 is instructed to fully open the aperture 62 via the aperture drive mechanism 64.

  In this way, the imaging operation ends.

  FIG. 13 is a time chart for explaining the shutter control operation during slit exposure.

  During normal shooting, as described above, shooting is performed by full-open exposure with the exposure opening 27 fully open. However, when the subject has high brightness, the exposure time elapses before the front curtain 25a is fully open. There is a case.

  In this case, the shutter drive control circuit 90 outputs the trailing curtain drive pulse without outputting the strobe tuning signal. In this case, the exposure opening 27 is not fully opened, and the slit opening having a predetermined width formed by the front curtain 25a and the rear curtain 25b moves on the exposure opening 27.

  The imaging operation at the time of slit exposure is the same as the flowchart shown in FIG.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.

  FIG. 14 is a cross-sectional view illustrating a configuration of an imaging module to which the shutter device according to the second embodiment of the present invention is applied.

  The second embodiment is different from the first embodiment described above only in the configuration of the imaging module, and the configuration and basic operation of the camera in which the imaging module is mounted are basically the same. 8 to 13 are the same as those shown in FIGS. 8 to 13, and the same reference numerals are given to the same parts, and illustration and description thereof are omitted.

  The imaging module 20a according to the second embodiment includes a shutter unit 21a and an imaging unit 22a. On the subject side (left side in FIG. 14) of the shutter unit 21a, a protective member 32 having a glass 45 attached to the opening is fixed so as to cover the front surface of the shutter unit 21 via spacers 33-36. Has been.

  Further, an optical filter 46 such as an infrared cut filter or a low-pass filter is attached to a portion where the opening 27b of the stator 29b is formed.

  The openings provided in the cover glass 42 are provided at positions corresponding to the openings 27 a and 27 b of the stators 29 a and 29 b and the openings 31 provided in the protection member 32. Thereby, the subject light taken in through the glass 45 attached to the protective member 32, the opening 27a, and the optical filter 46 is guided to the image sensor 40 that is a photoelectric conversion element. The image is photoelectrically converted.

  Thus, even if the optical filter 46 is mounted, the imaging module can be reduced in size, and the same effect as that of the first embodiment described above can be obtained.

  The same effect can be obtained even if the optical filter 46 is mounted at the position of the opening 27a of the stator 29a.

  As mentioned above, although embodiment of this invention was described, in the range which does not deviate from the summary of this invention other than embodiment mentioned above, this invention can be variously modified.

It is a figure explaining the drive principle of the electrostatic shutter apparatus which concerns on this invention. It is the figure which showed the drive circuit of this electret shutter while showing the cross section of an electret shutter typically. 2 shows an example of a voltage signal train created by the drive circuit 10 of FIG. 2 and applied to the drive electrodes 4A to 4D, where (a) shows the drive electrode 4A, (b) shows the drive electrode 4B, and (c). Is a drive electrode 4C, and (d) is a timing chart of the drive electrode 4D. It is a figure explaining operation | movement of the electret shutter 7 shown by FIG. 1 is an assembly diagram illustrating a configuration of an imaging module to which a shutter device according to an embodiment of the present invention is applied. FIG. It is sectional drawing which showed the structure of the state by which the imaging module of the structure of FIG. 5 was assembled. It is the figure which expanded and showed the junction part of the protection member 32 and the optical filter 37. FIG. It is a figure explaining operation | movement of the front curtain 25a and the rear curtain 25b. It is a block diagram which shows the system configuration | structure of the electric system of the camera which has the electrostatic shutter apparatus which concerns on one Embodiment of this invention. FIG. 10 is a configuration diagram illustrating signal connection between the shutter drive control circuit 90 and the shutter unit 21 of FIG. 9. It is a flowchart which shows the general imaging | photography operation | movement procedure of Bmicrocom85. It is a time chart explaining the shutter control operation at the time of full open exposure. It is a time chart explaining the shutter control operation at the time of slit exposure. It is sectional drawing which shows the structure of the imaging module to which the shutter apparatus of 2nd Embodiment which concerns on this invention is applied.

Explanation of symbols

  1, 29a, 29b ... Stator, 2 ... Mover, 3, 27a, 27b, 31 ... Opening, 4, 4A to 4D, 28a, 28b ... Drive electrode, 5, 5a, 5b, 26a, 26b ... Permanent polarization 7 ... electret shutter, 10 ... drive circuit, 12 ... pulse generation circuit, 13 ... phase shifter, 14 ... booster circuit, 20 ... imaging module, 21 ... shutter unit, 22 ... imaging unit, 25a ... Front curtain, 25b ... Rear curtain, 27 ... Exposure aperture, 32 ... Protection member, 33-36 ... Spacer, 37 ... Optical filter, 39 ... Storage container, 40 ... Image sensor, 42 ... Cover glass, 50 ... Body unit, 51 ... Lens unit, 52 ... Recording medium, 53 ... Strobe unit, 61a, 61b ... Photography lens, 62 ... Aperture, 65 ... Microcomputer for lens control (Lμcom), 70 ... Quick return mirror, 76 ... AF sensor unit, 80 ... Image sensor interface circuit, 81 ... Image processing controller, 85 ... Body control microcomputer (Bµcom), 90 ... Shutter drive control circuit, 93 ... Camera operation switch (SW), 95 ... power supply circuit, 97 ... power supply control microcomputer (P [mu] com), 98 ... power switch (SW), 101 ... flash light emitting unit, 103 ... strobe control microcomputer.

Claims (18)

A stator having an opening through which the subject luminous flux passes;
A plurality of electrode portions provided on the stator;
A movable element that receives an electrostatic force generated when a frequency voltage is applied to the electrode part, and is movable between a position for shielding the opening and a position for opening the opening,
A protective member having an opening through which the subject luminous flux passes and disposed so as to sandwich the movable element together with the stator;
In an electrostatic shutter device comprising:
An electrostatic shutter device, wherein an optical element for changing the optical characteristics of the subject light beam is embedded in the opening of the protective member.   The electrostatic shutter device according to claim 1, wherein the optical element is an infrared cut filter or a low-pass filter.   The electrostatic shutter device according to claim 1, wherein an optical element having characteristics different from those of the optical element embedded in the protective member is embedded in the opening of the stator.   The electrostatic shutter device according to claim 1, wherein the protective member is a glass plate, an acrylic plate, or a hard substrate. A stator having an opening through which the subject luminous flux passes;
A plurality of electrode portions provided on the stator;
A movable element that receives an electrostatic force generated when a frequency voltage is applied to the electrode part, and is movable between a position for shielding the opening and a position for opening the opening,
A protective member having a region through which the subject luminous flux passes and disposed so as to sandwich the movable element together with the stator;
In an electrostatic shutter device comprising:
An electrostatic shutter device, wherein an optical element having an infrared cut characteristic or a low-pass characteristic is formed in the region of the protective member. An image sensor;
A stator having an opening for guiding a subject luminous flux to the image sensor;
A plurality of electrode portions provided on the stator;
A movable element that receives an electrostatic force generated when a frequency voltage is applied to the electrode part, and is movable between a position for shielding the opening and a position for opening the opening,
A protective member having an opening through which the subject luminous flux passes and disposed so as to sandwich the movable element together with the stator;
Comprising
A digital camera, wherein an optical element for changing an optical characteristic of the subject light beam is embedded in the opening of the protective member.   The digital camera according to claim 6, wherein the optical element is an infrared cut filter or a low-pass filter.   The digital camera according to claim 6, wherein an optical element having characteristics different from those of the optical element embedded in the protective member is embedded in the opening of the stator. An image sensor;
A stator having an opening for guiding a subject luminous flux to the image sensor;
A plurality of electrode portions provided on the stator;
A movable element that receives an electrostatic force generated when a frequency voltage is applied to the electrode part, and is movable between a position for shielding the opening and a position for opening the opening,
A protective member having a region through which the subject luminous flux passes and disposed so as to sandwich the movable element together with the stator;
In an electrostatic shutter device comprising:
An electrostatic shutter device, wherein an optical element having an infrared cut characteristic or a low-pass characteristic is formed in the region of the protective member. A mover that can move to a position that blocks the passage area of the subject luminous flux;
A stator having a subject light flux passage area and provided with a plurality of drive electrodes for electrostatically driving the movable element;
A protective member having a passage region for the subject luminous flux and disposed so as to sandwich the movable element together with the stator;
An optical element that is attached to a passage region of the subject luminous flux of at least one of the stator and the protection member, and changes an optical characteristic of the subject luminous flux;
An electrostatic shutter device comprising:   The electrostatic shutter device according to claim 10, wherein the optical element is an infrared cut filter or a low-pass filter.   The electrostatic shutter device according to claim 10, wherein an optical element having a characteristic different from that of the optical element mounted on the protective member is mounted in a passage area of the subject luminous flux of the stator.   The electrostatic shutter device according to claim 10, wherein the protective member is a glass plate, an acrylic plate, or a hard substrate.   The electrostatic shutter device according to claim 10, wherein the protective member and the optical element are provided with a taper to reduce a thickness thereof toward a joint portion between the protective member and the optical element. An image sensor for imaging a subject;
A fixed mover that is movable to a position that shields the opening through which the subject luminous flux passes, and a plurality of drive electrodes that have a passage area for the subject luminous flux and electrostatically drive the movable element An electrostatic shutter device disposed on the front surface of the imaging device,
A protective member having an opening through which the subject luminous flux passes, and disposed so as to sandwich the moving element together with the stator of the shutter device;
An optical element that is attached to at least one opening of the stator and the protective member and changes the optical characteristics of the subject luminous flux;
A digital camera comprising:   The digital camera according to claim 15, wherein the optical element is an infrared cut filter or a low-pass filter.   The digital camera according to claim 15, wherein an optical element having a characteristic different from that of the optical element mounted on the protection member is mounted in the opening of the stator.   The digital camera according to claim 15, wherein the protective member and the optical element are provided with a taper to reduce a thickness thereof toward a joint portion between the protective member and the optical element.

Images