JP2009042568A - Foreign matter removing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To strike a balance between high rigidity and thinning of a wiper frame. <P>SOLUTION: The wiper frame 31 is constituted of a flat part 31a, an attaching part 31b for fixing a foreign matter removing part 33, a reinforcement part 31c for surrounding the periphery of the attaching part 31b, plate-spring-like spring parts 31d, 31e in both ends, in a wiper type cleaning unit 30 for removing foreign matter such as dust deposited on the surface of an optical filter 14, a recess is formed in a metal thin plate by contraction working by a press, a bottom part of the recess serves as the attaching part 31b, and a side part thereof serves as the reinforcement part 31c. The one end (spring part 31d) of the wiper frame 31 is attached to a nut 25 by a wiper attaching pin 32, and the other end (spring part 31e) of the wiper frame 31 is inserted into a groove part 26a of a wiper regulation member 26. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is used to remove foreign matters such as dust adhering to the surface of an optical element disposed in front of an image sensor incorporated in an electronic camera or the like or in front of an image display element incorporated in a data projector or the like. It is related with a suitable foreign material removal apparatus.

  A so-called electronic camera that captures still images and moving images using an imaging optical system and an image sensor such as a CCD or C-MOS sensor is a zoom optical system, a focusing optical system, a shutter, an iris (iris), and a quick return mirror. It is common to have a movable mechanism such as. Here, foreign matter such as wear dust discharged from the sliding parts of these movable mechanisms and dust entering from the outside is filtered by a filter (optical low-pass filter or infrared cut filter) disposed in the vicinity of the image sensor cover glass or image sensor. May adhere to the surface of the filter. When shooting is performed in a state where foreign matter is attached to the surface of the optical element in this way, the shadow of the foreign matter is reflected along with the subject image, and a high-quality image may not be obtained.

  In addition, in data projectors and projection televisions configured with a display element such as a liquid crystal panel, an illumination light source, and a projection optical system, foreign matter such as dust entering from the outside can adhere to the liquid crystal panel or the protective glass on the front surface thereof. is there. When projection is performed in a state where foreign matter is attached to the surface of the optical element in this way, the shadow of the foreign matter is reflected in the projected image, leading to a reduction in image quality.

  As a technique for removing such foreign matters, various mechanisms (wiper type foreign matter removing mechanisms) for cleaning the surface of the optical element using a wiper have been proposed.

  For example, in Patent Document 1 and Patent Document 2, a wiper blade having a flexible member such as rubber is supported by a motor shaft, and the glass surface of an image sensor incorporated in a digital single lens reflex camera is wiped and scanned. A mechanism for removing dust adhering to the surface is disclosed.

  Further, in Patent Document 3, both ends of a wiper member made of felt or a flocking brush are supported by a ribbon (belt), and the glass surface of the imaging device is linked with the operation of mounting the interchangeable lens on the camera body. A cleaning mechanism is disclosed.

  In Patent Document 4, a wiper member made of a shrinkable / elastic material such as a flocking material or a porous material is provided at the slit forming edge of the focal plane shutter, and the glass of the image sensor is used when the shutter is charged. A mechanism for cleaning the surface is disclosed.

JP 2001-298640 A JP 2003-18440 A JP 2005-5972 A JP 2003-5254 A

  In the wiper type foreign matter removing mechanism as described above, in order to obtain a uniform foreign matter removing effect over the entire area of the surface to be cleaned, the contact force distribution between the wiper member and the surface to be cleaned is made constant. Is required. For this purpose, it is necessary to increase the rigidity of the wiper member itself or a wiper arm (also referred to as a wiper frame) that supports the wiper member to prevent harmful elastic deformation.

  Further, when the wiper-type foreign matter removing mechanism is built in an optical device such as a camera, a shutter mechanism and an optical member are disposed adjacent to each other on the surface to be cleaned, and the space that can be occupied by the wiper mechanism is very small.

  As described above, the wiper type foreign matter removing mechanism is required to achieve both high rigidity for obtaining a stable foreign matter removing effect and thinning for accommodating in a narrow space. Then, there were the following drawbacks.

  In the structures disclosed in Patent Document 1 and Patent Document 2, since the wiper blade is mounted on the flat wiper arm, it is difficult to achieve both high rigidity and thinning.

  Further, in the structure disclosed in Patent Document 3, the felt or the flocked brush is brought into contact with the glass surface via the ribbon, but a configuration for increasing the rigidity of the wiper member is not disclosed. For this reason, it is difficult to make the pressure (contact force) distribution between the wiper member and the member to be cleaned uniform.

  In the structure disclosed in Patent Document 4, the wiper arm that supports the wiper member is also used as the shutter blade. In this case, in order to reduce the air resistance during travel, the shutter blades are extremely thin compared to ordinary structural members, so it is very difficult to provide a predetermined rigidity as a wiper arm.

  The present invention has been made in view of the above points, and an object thereof is to achieve both high rigidity and thinning of the wiper frame.

The foreign matter removing device of the present invention is a foreign matter removing device for removing foreign matter attached to the surface of an optical element, and is a belt-like or plate-like wiper that holds a foreign matter removing member so as to contact the surface of the optical element. A frame, and a drive mechanism that moves the wiper frame to wipe the surface of the optical element with the foreign matter removing member. The wiper frame includes an attachment portion that fixes the foreign matter removal member, and a periphery of the attachment portion. And a reinforcing portion that surrounds all or part of the optical element, wherein the thickness of the reinforcing portion in the normal direction of the surface of the optical element is greater than the thickness of the mounting portion.
Another foreign matter removing device of the present invention is a foreign matter removing device for removing foreign matter adhering to the surface of an optical element, and is a belt-like or plate-like shape that holds a foreign matter removing member so as to contact the surface of the optical element. A wiper frame and a drive mechanism for moving the wiper frame to wipe the surface of the optical element with the foreign matter removing member, and forming a concave portion in the body of the wiper frame, and removing the foreign matter at the bottom of the concave portion. The member is fixed.

  According to the present invention, it is possible to achieve both high rigidity and thinning of the wiper frame that holds the foreign matter removing member, and it is possible to reliably wipe the entire surface of the optical element while reducing the size of the foreign matter removing device.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
(First embodiment)
FIG. 1 is a diagram showing a configuration of a digital single-lens reflex camera including a foreign matter removing apparatus to which the present invention is applied. The digital single-lens reflex camera is composed of a camera body 1 and an interchangeable lens unit 80. The figure shows a preparation state for photographing of a digital single-lens reflex camera.

  An interchangeable lens unit 80 is detachably fixed to the camera body 1 by a camera mount 2 and a lens mount 82. At this time, the camera-side contact 3 and the lens-side contact 84 come into contact with each other, so that an in-camera control circuit and an in-lens control circuit are electrically connected to each other. And communication for controlling the lens.

  The light beam that has passed through the photographing optical system 81 and the iris diaphragm 83 of the interchangeable lens unit 80 is incident on the main mirror 5 of the camera body 1. The main mirror 5 is a half mirror, and the light beam reflected here is guided to the finder screen 9, and a subject image is formed on the finder screen 9. The photographer can observe the subject image on the finder screen 9 through the penta roof prism 11 and the eyepiece 12. The photometric sensor 16 measures the brightness of the subject image on the finder screen 9.

  On the other hand, the light beam transmitted through the main mirror 5 is reflected downward by the sub mirror 7 and guided to the focus detection device 10. The focus detection device 10 detects a focus shift amount of the photographic optical system 81, a so-called defocus amount, and calculates a lens driving amount for driving the photographic optical system 81 so that the photographic optical system 81 is in focus. When this lens driving amount is sent to the interchangeable lens unit 80 via the contacts 3 and 84, the lens controls a motor (not shown) and drives the photographing optical system 81 to adjust the focus.

  The main mirror 5 is bonded and fixed to a main mirror holding frame 6, and the main mirror holding frame 6 is pivotally supported by a hinge shaft 6a so as to be rotatable with respect to a mirror box (not shown). Further, the sub mirror 7 is bonded and fixed to the sub mirror holding frame 8, and the sub mirror holding frame 8 is rotatably supported with respect to the main mirror holding frame 6 by a hinge shaft 8a.

  A focal plane shutter 13 is disposed behind the sub mirror 7. The shutter front curtain 13a of the focal plane shutter 13 is in a normally closed state, that is, a state in which an image sensor 15 described later is shielded from light.

  Behind the focal plane shutter 13 is an optical filter 14 in which an optical low-pass filter and an infrared cut filter are integrated. At the time of shooting, the light beam that has passed through the optical filter 14 is incident on the image pickup device 15 that is disposed further rearward.

  The image pickup device 15 includes a cover glass 15a, a sensor package 15b, a sensor chip 15c, and a sensor substrate 15d. Here, the image pickup device or the image pickup means refers to a sensor chip 15c alone in a narrow sense, an image pickup device unit composed of the constituent members 15a to 15d in a broad sense, and a structure in which the image pickup device unit and the optical filter 14 are combined. Shall.

  A display device 60 such as an LCD is disposed on the back of the camera body 1. The display 60 displays information related to the shooting mode of the camera, a preview image before shooting, a confirmation image after shooting, and the like.

  In the space behind the shutter 13 and outside the optically effective surface of the optical filter 14, a wiper-type cleaning unit 30 for removing foreign matters such as dust adhering to the surface of the optical filter 14 as an optical element is disposed. . This cleaning unit 30 functions as the foreign matter removing apparatus of the present invention. Although described in detail later, the cleaning unit 30 includes a wiper frame 31 and a motor 24 as constituent members.

  The image sensor and cleaning unit 30 is fixed to the image sensor holding base 20.

  Here, FIG. 2 is a diagram showing a configuration of the cleaning unit 30, FIG. 2A is a plan view seen from the photographing lens side, and FIG. 2B is a cross-sectional view taken along line AA in FIG. FIG. 2 and FIG. 2C are cross-sectional views taken along the line BB in FIG. 3 is a perspective view of the wiper frame 31 of the first embodiment. FIG. 3A is a perspective view seen from the photographing lens side, and FIG. 3B is a perspective view seen from the image sensor side. is there. Hereinafter, the structure of the cleaning unit 30 will be described with reference to FIGS.

  In FIG. 2, the image sensor holding base 20 is provided with a motor base 21 on one end side (left side in FIG. 2) of the optical filter 14. The motor base 21 is manufactured by bending the upper and lower ends of a long metal plate, and a motor 24 is fixed to the lower end. A guide shaft 23 extending in the vertical direction is fixed inside the bent portion of the motor base 21. A lead screw 22 is integrally provided on the output shaft of the motor 24 and is arranged in parallel with the guide shaft 23. A nut 25 is screwed into the lead screw 22, and the nut 25 is configured to slide along the guide shaft 23 as the motor 24 rotates.

  Further, the wiper regulating member 26 is installed on the image sensor holding base 20 on the other end side (right side in FIG. 2) of the optical filter 14. The wiper regulating member 26 has a prismatic shape extending in the vertical direction on the paper surface of FIG. 2A, and in the extending direction of the prism, a groove 26a having a uniform cross-sectional shape as shown in FIG. Is formed.

  Next, the wiper frame 31 will be described. 2 shows a state in which the wiper frame 31 is incorporated in the cleaning unit 30, and FIG. 3 shows the wiper frame 31 alone. The wiper frame 31 holds the foreign matter removing member 33 so as to come into contact with the surface of the optical filter 14, and is made of a thin metal plate and has a strip shape or a plate shape.

  The wiper frame 31 includes a flat portion 31a, a mounting portion 31b for fixing the foreign matter removing member 33, a reinforcing portion 31c surrounding the mounting portion 31b, and leaf spring-shaped spring portions 31d and 31e at both ends. Specifically, a concave portion is formed in a metal thin plate by press working, and the bottom portion of the concave portion is an attachment portion 31b and the side portion is a reinforcing portion 31c.

  A foreign matter removing member 33 is fixed to the surface of the mounting portion 31b facing the optical filter 14 (the bottom of the recess). The foreign matter removing member 33 is thin in order to save space, has elasticity in the thickness direction in order to stabilize the contact state with the optical filter 14, and does not damage the optical filter 14. Characteristics are required. As a member that satisfies these conditions, a flocking member manufactured by electrostatic flocking, a cleaning cloth such as a cloth or a nonwoven fabric, a urethane foam sheet, an air filter, or the like is preferable. The thickness of the foreign substance removing member 33 is preferably about 0.3 mm to 1.5 mm in order to achieve both reduction in thickness and maintenance of elasticity, and is fixed to the attachment portion 31b using a double-sided adhesive tape or an adhesive. The

  Returning to FIG. 2, one end (spring portion 31 d) of the wiper frame 31 is attached to the nut 25 by the wiper attachment pin 32. Further, the other end (spring portion 31 e) of the wiper frame 31 is inserted into the groove portion 26 a of the wiper regulating member 26. The dimensions of the wiper mounting pin 32 and the wiper regulating member 26 are set so as to give a predetermined amount of bending to the spring portions 31d and 31e. Accordingly, the foreign matter removing member 33 held by the wiper frame 31 contacts the optical filter 14 with a predetermined pressure.

  A protective member 34 is disposed on the surface of the wiper frame 31 facing the optical filter 14 (flat portion 31a). The protective member 34 is provided so as to prevent contact with the optical filter 14 and damage even when the wiper frame 31 is scanned at an inclination, and a cloth or a rubber plate is preferable.

  The wiper position detectors 27 and 28 are for detecting that the wiper frame 31 has reached the lower end and the upper end of the driving range, and a photo reflector or the like is preferably used.

  In the cleaning unit 30 configured as described above, when the motor 24 is driven to rotate in the forward direction, the wiper frame 31 slides upward from the bottom of FIG. Wipe the surface of (scan). When the wiper position detection unit 28 detects that the wiper frame 31 has reached the upper end of the driving range, the motor 24 is driven in reverse. When the motor 24 is driven in reverse, the wiper frame 31 slides from the top to the bottom in FIG. When the wiper position detection unit 27 detects that the wiper frame 31 has reached the lower end of the driving range, the motor 24 is stopped. In the present embodiment, the motor 24, the nut 25, the lead screw 22, and the like constitute a drive mechanism referred to in the present invention.

  When the wiper frame 31 slides, the distal end portion of the spring portion 31 e moves while slidingly contacting the groove portion 26 a of the wiper regulating member 26. Therefore, the contact force between the foreign matter removing member 33 and the optical filter 14 is kept substantially constant from the start to the end of the foreign matter removing operation, and foreign matters such as dust attached to the surface of the optical filter 14 are removed.

  Here, referring to FIG. 3, a reinforcing portion 31c formed by press drawing is provided around the entire attachment portion 31b. And the thickness of the reinforcement part 31c in the normal line direction of the surface of the optical filter 14, in other words, the height is thicker (larger) than the thickness of the attachment part 31b. Thus, by providing the wiper frame 31 with the reinforcing portion 31c, it is possible to remarkably increase the bending rigidity particularly in the thickness direction. On the other hand, since the spring portions 31d and 31e are made of a thin metal plate as described above, the spring constant can be reduced.

  That is, in the wiper frame 31 of the present embodiment, the spring constant of the spring portions 31d and 31e, which are urging means, is reduced by using a thin metal plate or the like, and the reinforcing portion 31c is provided so as to surround the mounting portion 31b. Thus, the rigidity of the wiper frame 31 is maintained. Therefore, even if a dimensional error occurs in each member constituting the cleaning unit 30 and the image sensor, the spring constants of the spring portions 31d and 31e are small, so that fluctuations in the contact force of the foreign matter removing member 33 can be suppressed. Even if the contact force of the foreign matter removing member 33 fluctuates, the rigidity of the portion that holds the foreign matter removing member 33 is high and the elastic deformation of the wiper frame 31 is prevented. It is possible to maintain a uniform contact force distribution.

  FIG. 4 is a block diagram showing an electric circuit configuration of the digital single-lens reflex camera of the present embodiment. First, various circuits built in the camera body 1 will be described. Reference numeral 41 denotes a camera CPU that controls various controls of the camera body 1 and includes a calculation unit, a ROM, a RAM, an A / D converter, a D / A converter, a communication interface circuit, and the like. Reference numeral 42 denotes an in-camera power supply circuit, which includes a secondary battery such as a lithium ion battery and a booster circuit.

  A photometric sensor driving circuit 43 drives the photometric sensor 16, calculates a photometric result, and communicates the output to the camera CPU 41. Reference numeral 44 denotes a display driver circuit that controls display of the display 60. An operation switch drive circuit 45 determines whether various operation switches (not shown) such as a power switch, a release (shooting trigger) switch, a shooting mode selection switch, and the like have been operated. Reference numeral 46 denotes a detachable flash memory that records captured image data. Reference numeral 47 denotes a cleaning mechanism drive circuit that controls the drive of the cleaning unit 30 described above.

  Reference numeral 55 denotes an image sensor driving circuit that controls the image capturing operation of the image sensor 15 and transmits the acquired image signal to the camera CPU 41. Reference numeral 50 denotes an AF sensor drive circuit that drives an AF sensor built in the focus detection apparatus 10 and transmits a focus detection signal to the camera CPU 41. A mirror drive circuit 52 drives the main mirror holding frame 6 to move the main mirror 5 and the sub mirror 7 in and out of the photographing optical path. Reference numeral 53 denotes a shutter drive circuit that performs drive trigger control of the front curtain and rear curtain of the shutter 13 based on a command signal from the camera CPU 41, and drives a charge motor (not shown) after completion of exposure control to Charge the running spring.

  Next, various circuits built in the interchangeable lens unit 80 will be described. Reference numeral 91 denotes a lens CPU, which includes a calculation unit, ROM, RAM, A / D converter, D / A converter, communication interface circuit, and the like. The lens CPU 91 communicates with the camera CPU 41 to exchange various data and command signals, and controls the following circuits. Reference numeral 92 denotes an in-lens power circuit, which supplies the power supplied from the in-camera power circuit 42 to various circuits and actuators in the lens.

  A diaphragm driving circuit 93 controls the aperture diameter of the iris diaphragm 83. Reference numeral 94 denotes a focus drive circuit that drives a focus motor (not shown) to drive the focus adjustment lens back and forth in the optical axis direction.

  FIG. 5 is a flowchart for explaining the foreign substance removal operation of the digital single-lens reflex camera of the present embodiment. When the photographer turns on a main switch (not shown) installed in the camera body 1, the processing after step S <b> 101 is executed.

  In step S101, the cleaning unit 30 is driven. Specifically, the reciprocating scanning of the wiper frame 31 is performed by the energization control of the motor 24 as described above.

  In step S102, the apparatus stands by in a state of accepting shooting condition settings. Here, the photographer operates an operation switch (not shown) while viewing the display 60 to perform exposure control, focus adjustment, or recording image selection operation.

  In step S103, it is determined whether or not a cleaning instruction has been given by the photographer (whether or not a cleaning instruction operating member (not shown) has been operated). When the cleaning instruction is given, the process proceeds to step S104, and after the reciprocating scan of the wiper frame 31, the process proceeds to step S105. If no cleaning instruction has been given, the process proceeds to step S105.

  In step S105, it is determined whether or not a shooting preparation switch (not shown) has been turned on, and waits until the operation is turned on. When the photographing preparation switch is turned on, the process proceeds to step S106. In step S106, the brightness of the object scene is measured using the photometric sensor 16, and the aperture value and shutter speed are determined based on a predetermined exposure control program. Subsequently, in step S107, the focus state is detected using the focus detection device 10, and the focus adjustment lens of the photographing optical system is driven back and forth in the optical axis direction to perform focus adjustment.

  In step S108, it is determined whether or not a shooting start switch (not shown) has been turned on, and waits until the operation is turned on. When the photographing start switch is turned on, the process proceeds to step S109. In step S109, a shooting operation is executed. Specifically, first, the aperture diameter of the iris diaphragm 83 built in the interchangeable lens unit 80 is controlled, and the main mirror 5 and the sub mirror 7 are retracted out of the photographing optical path. Thereafter, drive control of the focal plane shutter 13 is performed, and a predetermined amount of light is given to the image sensor 15 to perform photographing. When shooting is completed, the iris diaphragm 83, the main mirror 5 and the sub mirror 7 are returned to the initial state. Then, the image sensor transmits the acquired image signal to the camera CPU 41, and the photographing is completed.

  In step S110, it is determined whether or not the main switch is turned off. If the main switch is not turned off, the process returns to step S102, and steps S102 to S209 are repeatedly executed. When the main switch is turned off, the process proceeds to step S111. In step S111, the wiper frame 31 is reciprocated and the process is terminated.

As mentioned above,
(1) Since the attachment part 31b and the reinforcement part 31c are formed in a part of the wiper frame 31 made of a thin metal plate, and the foreign matter removing member 33 having a predetermined thickness is accommodated in the attachment part 31b, the moving part is made thin and rigid. Maintenance and securing of the elasticity of the foreign matter removing member 33 can be achieved. Therefore, the contact force distribution between the foreign matter removing member 33 and the optical filter 14 can be made uniform, and unevenness in the foreign matter removal can be prevented.
(2) Since the spring portions 31d and 31e are integrally formed with the wiper frame 31 as urging means for bringing the foreign matter removing member 33 into contact with the optical filter 14, the cleaning unit 30 can be reduced in size and provided at low cost. it can.
(3) Since the urging means (spring portions 31d and 31e) are made of a thin metal plate, the spring constant can be reduced, and the urging force can be changed even if dimensional errors of various members constituting the cleaning unit 30 occur. Can be suppressed. As a result, a stable foreign matter removal effect can be obtained, and an increase in load fluctuations of the motor 24 that is the driving means can be prevented.

(Second Embodiment)
FIG. 6 is a perspective view of the wiper frame 131 of the second embodiment. A wiper frame 131 according to the second embodiment is a modification of the wiper frame 31 according to the first embodiment. FIG. 6 corresponds to a perspective view seen from the image sensor side in FIG. Since the configuration other than the wiper frame is the same as that of the first embodiment, detailed description thereof is omitted.

  Similar to the first embodiment, the wiper frame 131 holds the foreign matter removing member 33 so as to come into contact with the surface of the optical filter 14, and is made of a thin metal plate and has a strip shape or a plate shape.

  The wiper frame 131 includes an attachment portion 131b for fixing the foreign matter removing member 33, reinforcing portions 131c provided above and below the attachment portion 131b, and leaf spring-like spring portions 131d and 131e at both ends. Specifically, both long sides of the metal thin plate are bent by a press bending process to form a wall, and the wall serves as a reinforcing portion 131c.

  Here, referring to FIG. 6, a reinforcing portion 131 c formed by press bending is provided in a part of the periphery of the attachment portion 131 b. And the thickness of the reinforcement part 131c in the normal line direction of the surface of the optical filter 14, in other words, the height is thicker (larger) than the thickness of the attachment part 131b. Thus, by providing the reinforcement part 131c in the wiper frame 131, especially the bending rigidity of a plate | board thickness direction can be improved markedly. On the other hand, since the spring portions 131d and 131e are made of a thin metal plate as described above, the spring constant can be reduced.

  In the wiper frame 131 of the second embodiment, since there is no flat portion 31a referred to in the wiper frame 31 of the first embodiment, the bending rigidity is slightly reduced, but the width in the scanning direction can be reduced, and the size is small. It is advantageous to make.

(Third embodiment)
In the first and second embodiments, the wiper frame made of a thin metal plate has been described. In the third embodiment, an injection-molded resin wiper frame 231 is described. Since the configuration other than the wiper frame is the same as that of the first embodiment, detailed description thereof is omitted.

  7A and 7B are perspective views of the wiper frame 231 according to the third embodiment. FIG. 7A is a perspective view seen from the photographing lens side, and FIG. 7B is a perspective view seen from the image sensor side. The wiper frame 231 holds the foreign matter removing member 33 so as to come into contact with the surface of the optical filter 14, and is manufactured by injection molding of a resin and has a strip shape or a plate shape. As the resin, a liquid crystal polymer suitable for thin-wall molding is preferable, but PC (polycarbonate), ABS (acrylic butadiene styrene) or the like may be used.

  The wiper frame 231 includes a flat portion 231a, a mounting portion 231b for fixing the foreign matter removing member 33, and leaf spring-like spring portions 231d and 231e at both ends. Specifically, a concave portion having a depth of about 0.8 mm is formed at the center of a flat plate having a thickness of about 2.0 mm, and the bottom of the concave portion is used as an attachment portion 231b. In this case, the flat part 231a becomes a thick part surrounding the entire periphery of the attachment part 231 and functions as a reinforcing part.

  Since the thickness of the mounting portion 231b is 1.2 mm and the thickness of the surrounding flat portion 231a is 2.0 mm, the flat portion 231a in the normal direction of the surface of the optical filter 14 (acts as a reinforcing portion). Is thicker than the thickness of the mounting portion 231b.

  Since the foreign matter removing member 33 having a thickness of about 1.0 mm is attached to the mounting portion 231b, the foreign matter removing member 33 protrudes from the wiper frame 231 (the flat portion 231a thereof) by about 0.2 mm.

  In the wiper frame 231 of the present embodiment, the bending rigidity is defined by the thickest flat portion 231a, and elastic deformation is prevented. Moreover, since the relatively thick foreign matter removing member 33 can be attached to the thin mounting portion 231b, the foreign matter removing member 33 can be elastically deformed. On the other hand, thin plate-like spring portions 231d and 231e are integrally formed at both ends of the wiper frame 231 (flat portion 231a), the spring portion 231d is attached to the nut 25, and the spring portion 231e is a groove portion of the wiper regulating member 26. 26a.

  In the above configuration, when the motor 24 is driven, the nut 25 moves according to the rotation of the lead screw 22, and the wiper frame 231 scans the surface of the optical filter 14. At this time, a predetermined contact force is generated between the foreign matter removing member 33 and the optical filter 14 due to elastic deformation of the spring portions 231d and 231e, as in the first embodiment. Moreover, since the bending rigidity of the wiper frame 231 is enhanced as described above, elastic deformation is prevented even if a contact force is generated. Further, since the foreign matter removing member 33 has elasticity in the thickness direction, it is possible to maintain a uniform contact force distribution with the optical filter 14 and to efficiently remove foreign matter attached to the surface of the optical filter 14.

As mentioned above,
(1) A mounting portion 231b is formed on a part of a flat plate-like wiper frame 231 molded from resin, and a foreign matter removing member 33 having a predetermined thickness is accommodated in the mounting portion 231b, and the mounting portion is provided around the mounting portion 231b. A reinforcing portion (flat portion 231a) thicker than 231b is provided. Thereby, it is possible to reduce the thickness of the moving part, maintain rigidity, and ensure the elasticity of the foreign matter removing member 33. Therefore, the contact force distribution between the foreign matter removing member 33 and the optical filter 14 can be made uniform, and unevenness in the foreign matter removal can be prevented.
(2) Since the spring portions 231d and 2 "31e are integrally formed with the wiper frame 231 as an urging means for bringing the foreign matter removing member 33 into contact with the optical filter 14, the cleaning unit 30 is reduced in size and provided at low cost. be able to.
(3) Since the biasing means (spring portions 231d and 231e) are thinly molded using a resin material having good fluidity, the spring constant can be reduced, and dimensional errors of various members constituting the cleaning unit 30 Even if this occurs, the change in the urging force can be suppressed. As a result, a stable foreign matter removal effect can be obtained, and an increase in load fluctuations of the motor 24 that is the driving means can be prevented.

(Fourth embodiment)
FIG. 8 is a perspective view of the wiper frame 331 of the fourth embodiment. A wiper frame 331 of the fourth embodiment is a modification of the wiper frame 231 of the third embodiment. Since the configuration other than the wiper frame is the same as that of the first embodiment, detailed description thereof is omitted.

  The wiper frame 331 includes a flat portion 331a, a mounting portion 331b for fixing the foreign matter removing member 33, and leaf spring-like spring portions 331d and 331e at both ends, and the outer shape thereof is the wiper frame 231 of the second embodiment. The two thin metal plates 331f are inserted above and below the attachment portion 331b. In this case, since the width of the metal plate 331f extends in the thickness direction of the wiper frame 331, the reinforcement effect of the metal plate 331f is added to the reinforcement effect of the flat portion 331a, and the bending rigidity is increased without increasing the thickness of the wiper frame 331. It can be greatly improved.

  The present invention can achieve the same effect when applied to an image display device such as a data projector in addition to a digital camera.

It is a figure which shows the structure of the digital single-lens reflex camera containing the foreign material removal apparatus to which this invention is applied. It is a figure which shows the structure of the cleaning unit of 1st Embodiment. It is a perspective view of the wiper frame of a 1st embodiment. It is a block diagram which shows the electric circuit structure of the digital single-lens reflex camera of 1st Embodiment. It is a flowchart for demonstrating the foreign material removal operation | movement of the digital single-lens reflex camera of 1st Embodiment. It is a perspective view of the wiper frame of a 2nd embodiment. It is a perspective view of the wiper frame of a 3rd embodiment. It is a perspective view of the wiper frame of a 4th embodiment.

Explanation of symbols

30 Cleaning unit 21 Motor base 22 Lead screw 23 Guide shaft 24 Motor 25 Nut 31, 131, 231, 331 Wiper frame 31b, 131b, 231b, 331b Mounting portion 31c, 131c, 231c, 331c Reinforcing portion 31d, 131d, 231d, 331d Spring portion 31e, 131e, 231e, 331e Spring portion 32 Wiper mounting pin 33 Foreign matter removing member 34 Protective member

Claims (6)

A foreign matter removing apparatus for removing foreign matter attached to the surface of an optical element,
A belt-like or plate-like wiper frame that holds a foreign matter removing member so as to contact the surface of the optical element;
A drive mechanism for moving the wiper frame to wipe the surface of the optical element with the foreign matter removing member;
The wiper frame includes an attachment portion for fixing the foreign matter removing member and a reinforcement portion surrounding all or a part of the attachment portion, and the thickness of the reinforcement portion in the normal direction of the surface of the optical element. Is larger than the thickness of the mounting portion.   The foreign matter removing apparatus according to claim 1, wherein the wiper frame is made of a metal plate, and the attachment portion and the reinforcing portion are formed by pressing.   The foreign matter removing apparatus according to claim 1, wherein the wiper frame is formed of a resin, and the reinforcing portion includes a thick portion provided around the attachment portion.   4. The foreign matter removing apparatus according to claim 2, wherein an urging means for generating a contact force between the optical element and the foreign matter removing member is integrally formed with the wiper frame.   The foreign matter removing apparatus according to claim 4, wherein the urging unit includes a leaf spring-like spring portion integrally formed with the wiper frame. A foreign matter removing apparatus for removing foreign matter attached to the surface of an optical element,
A belt-like or plate-like wiper frame that holds a foreign matter removing member so as to contact the surface of the optical element;
A drive mechanism for moving the wiper frame to wipe the surface of the optical element with the foreign matter removing member;
A foreign matter removing apparatus, wherein a concave portion is formed in the wiper frame, and the foreign matter removing member is fixed to a bottom portion of the concave portion.

Images