JP2010109502A - Imaging unit, assembling method of imaging unit, and imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve positioning precision of an optical filter and an imaging element while improving imaging performance by arranging a movable optical filter, and to achieve downsizing. <P>SOLUTION: An imaging unit is provided with: a base material with an aperture part; the imaging element which receives a light passing through the aperture part, and converts the light to an electrical signal; and a filter material with an optical filter part which intervenes between the aperture part and the imaging element. The base material is characterized to be provided with: an imaging element attaching part which attaches the imaging element; and a filter material attaching part which attaches the filter material between a first position so that the optical filter part intervenes between the aperture part and the imaging element, and a second position so that the optical filter part does not intervene between the aperture part and the imaging element so that the filter material is movable. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image capturing technique.

  Imaging devices using an imaging device such as a CCD image sensor or a CMOS image sensor are widely known as representatives of digital cameras and digital video cameras. Further, there are also known more compact ones such as a mobile phone camera and an in-vehicle camera for photographing the rear of a vehicle.

  As a configuration of a small camera, for example, Patent Document 1 discloses a case in which a case, a lens, an optical filter (infrared cut filter), and a substrate on which an imaging circuit is mounted are attached. However, the one of Patent Document 1 is fixedly provided so that the optical filter is always located on the optical path, and the followability to the change in the brightness of the subject becomes insufficient, and the photographing performance is inferior. In particular, if the infrared cut filter is fixedly provided, the amount of light may not be sufficient when shooting in a dark part such as at night, and the resolution may deteriorate.

  On the other hand, there is also known an optical filter that is improved in photographing performance by being configured to be movable between a position on the optical path and a position outside the optical path (for example, Patent Document 2). When an infrared cut filter is configured to be movable as an optical filter, the infrared cut filter forms an image of light in the visible light region during daytime, and color shooting is performed at night, and the infrared cut filter is removed at night to reveal the visible light region. In addition to the above light, monochrome imaging can be performed by forming an image of light in the near infrared region.

JP 2004-88181 A JP 2002-189238 A

  In general, the movable mechanism of the optical filter is manufactured as a unit different from the unit on which the lens barrel is mounted and the unit on which the image sensor is mounted, and is incorporated on the optical path between the lens barrel and the image sensor. Patent Document 2 discloses a lens barrel in which a movable mechanism of an optical filter is provided to form a unit, but the imaging device is a separate unit.

  In such a configuration, the units are connected in the optical path direction and the number of parts increases, making it difficult to reduce the size. There is also a problem that the positioning accuracy of the optical filter and the image sensor with respect to the optical path is affected by the mounting accuracy between the units.

  An object of the present invention is to improve the positioning performance between the optical filter and the image sensor and to reduce the size while improving the photographing performance by moving the optical filter.

  According to the present invention, a base member having an opening, an imaging element that receives light passing through the opening and converts it into an electrical signal, and an optical filter section that is interposed between the opening and the imaging element In the imaging unit including the filter member, the base member is an image sensor mounting portion to which the image sensor is mounted, and the optical filter portion is interposed between the opening and the image sensor. A filter member mounting portion to which the filter member is mounted so that the filter member is movable between the second position where the optical filter portion is not interposed between the opening and the imaging element; An imaging unit characterized by comprising: is provided.

  In the imaging unit of the present invention, since the filter member having the optical filter portion is movable between the first and second positions, the photographing performance can be improved. In addition, the filter member and the image sensor can be reduced in size by being attached to the common base member. Furthermore, by attaching the filter member and the imaging element to the base member having the opening that defines the optical path, the positioning accuracy of the opening, the optical filter unit, and the imaging element can be improved.

  According to the invention, in the imaging unit assembling method, the imaging unit includes a front part, a back part opposite to the front part, and an opening penetrating between the front part and the back part. A base member having: an image sensor that receives light passing through the opening and converts the light into an electrical signal; an image sensor mounting portion that protrudes from the back surface of the base member and to which the image sensor is attached; A first position where the optical filter portion is interposed between the opening portion and the imaging element; and the optical filter portion is the first position where the optical filter portion is interposed between the opening portion and the imaging element. A filter member provided movably between a second position that is not interposed between the opening and the image sensor, and a drive that moves the filter member between the first position and the second position Means and the imaging device A partition plate interposed between the filter member and partitioning the moving space of the filter member and the installation space of the imaging device, and the assembling method includes the filter on the back surface of the base member. A first attachment step for attaching a member and the driving means; a second attachment step for attaching the partition plate to the base member from the back surface side of the base member after the first attachment step; and a second attachment step. And a third attachment step of attaching the image pickup device to the image pickup device attachment portion from the back surface side of the base member.

  In the assembling method of the present invention, since the filter member having the optical filter portion can move between the first and second positions, an imaging unit with improved imaging performance can be provided. Further, the image pickup unit can be downsized by attaching the filter member and the image pickup element to the common base member. Furthermore, by attaching the filter member and the imaging element to the base member having the opening that defines the optical path, the positioning accuracy of the opening, the optical filter unit, and the imaging element can be improved. In addition, assembly workability can be improved by sequentially assembling the filter member, the drive means, the partition plate, and the image sensor from the back surface side of the base member.

  Further, according to the present invention, a base member having an opening, an imaging element that receives light passing through the opening and converts it into an electrical signal, and an optical intervening between the opening and the imaging element In the imaging device including a filter member having a filter portion, the base member is interposed between the image sensor mounting portion to which the image sensor is mounted, and the optical filter portion is interposed between the opening and the image sensor. A filter member mounting portion to which the filter member is mounted such that the filter member is movable between a first position and a second position where the optical filter portion is not interposed between the opening and the imaging device. And driving means for moving the filter member between the first position and the second position, and controlling the driving means based on the electrical signal output from the imaging device. Imaging apparatus is provided, characterized in that it comprises a control means.

  In the image pickup apparatus of the present invention, since the filter member having the optical filter portion is movable between the first and second positions, photographing performance can be improved. In addition, the filter member and the image sensor can be reduced in size by being attached to the common base member. Furthermore, by attaching the filter member and the imaging element to the base member having the opening that defines the optical path, the positioning accuracy of the opening, the optical filter unit, and the imaging element can be improved. In addition, the position of the filter member having the optical filter portion can be automatically switched to a position according to the imaging environment by the control means.

  As described above, according to the present invention, it is possible to improve the positioning performance between the optical filter and the image sensor and reduce the size while improving the photographing performance by moving the optical filter.

<First Embodiment>
FIG. 1 is a perspective view of an imaging unit A according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of the imaging unit A. The imaging unit A includes a base member 1 that constitutes a base plate of the imaging unit A, an imaging element 2, a filter member 3, a drive device 4 that moves the filter member 3, a partition plate 5, a lens barrel 6, A substrate 7 on which the imaging device 2 is mounted and a terminal board 9 are provided.

  The base member 1 includes a plate-shaped rectangular base portion 11 and four side wall portions 12 surrounding the base portion 11. For example, the base member 1 is integrally formed from a resin including each component on a back surface portion 11 b described later. The base part 11 penetrates between the front part 11a to which the lens barrel 6 is attached, the back part 11b opposite to the front part 11a, and the front part 11a and the back part 11b (that is, penetrates the base part 11). And an opening 11c. A part of the lens barrel 6 is inserted into the opening 11c and fixed to the front surface 11a with an adhesive or the like.

  The image pickup device 2 is an image pickup device such as a CCD image sensor or a CMOS image sensor. When the image pickup device 2 passes through the lens barrel 6, it receives the light passing through the opening 11 c and converts it into an electrical signal. In the present embodiment, the image sensor 2 has a substantially rectangular parallelepiped shape, and the light receiving surface thereof is covered with a cover glass 21. The image pickup device 2 is mounted on the substrate 7 by being soldered so that the light receiving surface thereof faces the opening 11c.

  The filter member 3 includes a base material 31, an optical filter portion 32 formed on the base material 31, a circular hole 33, and a long hole-like engagement hole 34. The base material 31 is, for example, a thin and transparent resin substrate such as PET. In the present embodiment, the optical filter unit 32 is a filter that adjusts the transmission of light in the infrared region, and is an infrared cut filter that mainly restricts the transmission of light in the infrared region. However, the optical filter unit 32 may be a filter that adjusts the transmission of light in the visible region, and may be, for example, an ND filter that mainly restricts the transmission of light in the visible region.

  In the case of this embodiment, the optical filter part 32 is an optical thin film laminated on a partial region on the substrate 31. This optical thin film can be formed by laminating a multilayer film sine of transmitted light on the substrate 31 by a physical lamination method such as vapor deposition. Here, the optical thin film constituting the optical filter portion 32 can be separately prepared and bonded to the base material 31 to form the optical filter portion 32. However, the optical thin film is directly laminated on the base material 31 by a physical lamination method. The filter member 3 can be made thinner by forming the filter member 3.

  The optical filter unit 32 may be formed over the entire area of the base material 31, but a part of the area is sufficient as in the present embodiment, and all the light received by the imaging device 2 is transmitted through the optical filter unit 32. What is necessary is just to have the magnitude | size which can pass.

  In the case of this embodiment, the drive device 4 is a rotary solenoid type actuator, but other actuators can also be employed. The drive device 4 includes a stator yoke 41 made of a soft magnetic material, a rotor 42, and an exciting coil unit 43. FIG. 3A is a perspective view of the rotor 42. The rotor 42 includes a cylindrical rotor magnet 42a and a connecting member 42b having a pin portion 42b 'inserted into the engagement hole 34 of the filter member 3 and a hole 42b "concentric with the rotor magnet 42a.

  The outer surface of the rotor magnet 42a is magnetized in two poles (N, S) in the circumferential direction. In the present embodiment, the connecting member 42b is made of resin, and the rotor magnet 42a and the connecting member 42b are integrally formed by insert molding. The rotor magnet 42a and the connecting member 42b may be integrated by, for example, pressing a part of the connecting member 42b into the center hole of the cylindrical rotor magnet 42a.

  Referring to FIG. 2, the stator yoke 41 has an opening 41a and a slit 41b communicating with the opening 41a, and its outer shape has a horseshoe shape. The opening 41a is formed in a C shape so as to surround the rotor magnet 42a, and the rotor magnet 42a is disposed in the opening 41a. A portion of the stator yoke 41 around the opening 41a forms a magnetic pole that faces the rotor magnet 42a with a gap. The exciting coil unit 43 is configured by winding a coil around a bobbin having a through hole. The exciting coil unit 43 is attached to the stator yoke 41 by inserting a portion 41c of the stator yoke 41 into the through hole of the bobbin.

  The drive device 4 having such a configuration supplies the drive current to the coil of the excitation coil unit 43 to excite the stator yoke 41, so that the rotor magnet 42a rotates around the axis of the rotor magnet 42a in the opening 41a. In addition, the direction of rotation can be controlled by the sign of the drive current.

  Next, FIG. 3 is a rear view of the base member 1, and is a view of the base member 1 as viewed from the back surface portion 11b side. The back surface part 11b has attachment parts 13a to 13d to which the image sensor 2 is attached. The attachment portions 13a to 13d are formed so as to protrude from the back surface portion 11b and have a substantially L-shaped cross section. Two side surfaces of the attachment portions 13 a to 13 d on the opening 11 c side are in contact with the corners of the image sensor 2. In the present embodiment, the image pickup device 2 can be positioned in the direction orthogonal to the optical path direction by the attachment portions 13a to 13d.

  The back surface portion 11b also includes an attachment portion 15 to which the filter member 3 is attached. The mounting portion 15 is a shaft that protrudes from the back surface portion 11 b and is inserted into the hole 33 of the filter member 3 to support the filter member 3 so as to be rotatable about the axis of the mounting portion 15. In the present embodiment, the base member 1 is a shaft body and the filter member 3 side is a hole, but the base member 1 side is a hole and the filter member 3 side is a shaft body. It is good also as a structure to support. In the present embodiment, the filter member 3 is configured to move by rotation, but may be configured to move by parallel movement. However, the moving space of the filter member 3 can be reduced if the rotating configuration is adopted.

  The back surface part 11b also has rail parts 16a and 16b. The rail portions 16a and 16b are formed so as to protrude from the back surface portion 11b and extend in the moving direction of the filter member 3. The rail portions 16a and 16b form a gap between the back surface portion 11b and the filter member 3 so that the filter member 3 does not slide in contact with the back surface portion 11b when the filter member 3 rotates. The member 3 slides on the rail portions 16a and 16b when rotating. By forming the rail portions 16a and 16b, the sliding area between the filter member 3 and the back surface portion 11b can be reduced, and the filter member 3 can be prevented from being damaged.

  The back surface portion 11 b also has a stopper portion 17. The stopper portion 17 is formed so as to protrude from the back surface portion 11b, and comes into contact with the filter member 3 to limit a rotation range in one direction of the rotation direction of the filter member 3. The rotation range of the filter member 3 in the other direction is limited by the mounting portion 13d. In the present embodiment, the mounting portion 13d also functions as a member that limits the rotation range of the filter member 3.

  The back surface part 11b also has an attachment part 18 to which the drive device 4 is attached. The mounting portion 18 protrudes from the back surface portion 11b and is inserted into the hole 42b ″ of the rotor 42. The shelf portions 18c and 18d, which protrude from the back surface portion 11b and on which the stator yoke 41 is placed, and the shelf portion 18c. And a recess 18b into which the rotor magnet 42a is inserted, and a recess 18e formed by the shelf portions 15c and 18d and the side wall portion 12 into which the exciting coil unit 43 is inserted.

  4A is a view showing a state in which the filter member 3 and the drive device 4 are assembled, and FIG. 4B is a view showing a state in which the filter member 3 and the drive device 4 are assembled to the back surface portion 11b. Since the filter member 3 is rotatably supported by the attachment portion 15, the filter member 3 can be rotated from a position indicated by a solid line to a position indicated by a broken line with the attachment portion 15 as a rotation center.

  The position indicated by the solid line is a first position where one side portion of the filter member 3 is in contact with the stopper portion 17, and the optical filter portion 32 is interposed between the opening portion 11 c of the base member 1 and the imaging element 2. Position. When the filter member 3 is located at the first position, the light received by the image sensor 2 is light transmitted through the optical filter unit 32.

  Among the positions indicated by the broken lines, the left side position in the drawing is such that the other side portion of the filter member 3 is in contact with the mounting portion 13d and the optical element is provided between the opening portion 11c of the base member 1 and the imaging element 2. This is the second position where the filter part 32 is not interposed. When the filter member 3 is located at the second position, the light received by the imaging device 2 is light that has not passed through the optical filter unit 32.

  The rotor 42 of the drive device 4 is rotatably supported by the shaft body 18a of the back surface portion 11b, and the pin portion 42b 'of the rotor 42 is inserted into the engagement hole 34 of the filter member 3. When a drive current is supplied to the coil of the exciting coil unit 43 to excite the stator yoke 41 and the rotor 42 rotates about the axis of the shaft body 18a, the pin portion 42b 'moves in an arc shape and the filter member 3 rotates. Will do.

  Here, even if the supply of the drive current to the coils of the exciting coil unit 43 is stopped, the rotational force can be applied to the rotor 42 by the detent torque between the stator yoke 41 and the rotor magnet 42a. For example, even if the drive current is stopped after the drive current is supplied to the coil of the exciting coil unit 43 and the filter member 3 is moved from the first position to the second position, the rotor 42 is driven by the detent torque. The rotating force is urged to the filter member 3 to rotate. However, the filter member 3 is restricted by the mounting portion 13d and does not rotate, but continues to be positioned at the second position. Even if the drive current is stopped after the drive current is supplied to the coil of the exciting coil unit 43 and the filter member 3 is moved from the second position to the first position, The rotor 42 tries to rotate, and rotational force is urged to the filter member 3. In this case, the filter member 3 is restricted by the stopper portion 17 and does not rotate but continues to be positioned at the first position.

  Thus, due to the action of the detent torque, when the position of the filter member 3 is changed, it is sufficient to supply the drive current only during the rotation, and the power consumption can be reduced. Further, the filter member 3 does not rotate unexpectedly due to vibration of the imaging unit A or the like.

  Next, in the case of the present embodiment, as shown in FIG. 3B, the mounting portion 18 is a space in which the image sensor 2 is surrounded by the two side surfaces of the mounting portions 13 a to 13 d on the opening 11 c side. As shown in FIG. 4B, the driving device 4 is disposed so as to avoid the space where the image sensor 2 is disposed. The drive device 4 is located on the side of the image pickup device 2 when the image pickup unit A is viewed in the optical path direction (the opening 11c-the image pickup device 2 direction). It is arranged so as not to overlap in the direction. For this reason, the imaging unit A can be thinned in the optical path direction.

  Next, another configuration of the base member 1 will be described with reference to FIG. The back surface part 11b includes a plurality of protrusions 14a to 14d protruding from the back surface part 11b. Each of the protruding portions 14a to 14d protrudes from the back surface portion 11b by the same height, and the top portion is flat.

  The projecting portions 14a to 14d function as spacers whose tops abut against the partition plate 5 and separate the back surface portion 11b and the partition plate 5 from each other. The partition plate 5 is interposed between the image sensor 2 and the filter member 3, and the moving space of the filter member 3 between the back surface portion 11 b and the partition plate 5, and the image sensor between the partition plate 5 and the substrate 7. 2 arrangement space.

  By providing the partition plate 5 and partitioning the moving space of the filter member 3 and the installation space of the image sensor 2, the filter member 3 is prevented from slidingly contacting the image sensor 2, and the optical filter unit 32 and the image sensor 2 can be prevented from being damaged. The image sensor 2 generates heat when driven. When the filter member 3 is made of a resin material as in this embodiment, the filter member 3 may be deformed by heat. In the present embodiment, the heat generated by the image sensor 2 by the partition plate 5 becomes difficult to be transmitted to the filter member 3, and deformation of the filter member 3 can be prevented. For this reason, as for the partition plate 5, what has high heat conductivity, such as a metal plate, is desirable, for example.

  With reference to FIG. 2, the partition plate 5 has three engaging portions 51 on the periphery thereof. A hole is formed in the engaging portion 51, and an engaging claw 12 a formed on the outer surface of the side wall portion 12 of the base member 1 is inserted into and engaged with the hole. The partition plate 5 is mounted on the back side of the base member 1 by the engagement between the engagement portion 51 and the engagement claw 12a. FIG. 5 is a perspective view showing a state in which the partition plate 5 is mounted on the base member 1. In the present embodiment, the partition plate 5 is mounted on the base member 1 by engaging the engaging portion 51 and the engaging claw 12a. However, a mounting structure using screws may be used.

  In the case of the present embodiment, the protrusions 14a to 14d are formed so as to be connected to the attachment parts 13a to 13d, respectively, and the height from the back surface part 11b is higher than the protrusions 14a to 13d than the attachment parts 13a to 13d. 14d is lower. For this reason, as shown in FIG. 5, in a state where the partition plate 5 is attached to the base member 1, the attachment portions 13 a to 13 d protrude behind the partition plate 5. For this reason, the imaging device 2 can be attached to the attachment portions 13a to 13d from behind the partition plate 5. FIG. 6 shows a state in which the image sensor 2 is attached to the attachment portions 13a to 13d from the state of FIG. 6 shows a state in which only the image pickup device 2 is attached to the attachment portions 13a to 13d. However, the image pickup device 2 is attached to the attachment portions 13a to 13d while being mounted on the substrate 7. .

  With reference to FIGS. 2 and 5, the partition plate 5 has an opening 53 concentric with the center line of the opening 11 c of the base member 1. The opening 53 is set to a size such that the optical path defined by the lens barrel 6 and the partition plate 5 do not interfere with each other. The partition plate 5 also has holes 54a to 54b through which the attachment portions 13a to 13d are inserted. Each hole 54a thru | or 54b has a shape according to each cross-sectional shape of the attachment parts 13a thru | or 13d to penetrate.

  The partition plate 5 also has a rail portion 52 that protrudes toward the base member 1 by causing a part thereof to bulge toward the base member 1. The rail part 52 is extended in the moving direction of the filter member 3, and the filter member 3 is not slidably contacted with the partition plate 5 when the filter member 3 rotates. A void is formed. The filter member 3 slides on the rail portion 52 when rotating. By forming the rail portion 52, the sliding area between the filter member 3 and the partition plate 5 can be reduced, and the filter member 3 can be prevented from being damaged.

  The partition plate 5 also has a hole 55 for avoiding interference between the pin portion 42 b of the rotor 42 and the partition plate 5, and a hole 56 for avoiding interference between the mounting portion 15 of the base member 1 and the partition plate 5. And having.

  Next, referring to FIG. 2, the base member 1 is integrally provided with two cylindrical portions 19 having internal threads engraved on the inner peripheral surface at two corners thereof. The two cylindrical portions 19 protrude from the back side of the base member 1 by the same height. The substrate 7 has holes 71 formed at two corners. Thus, the substrate 7 can be fixed to the base member 1 by inserting the shaft portion of the bolt 8 on which the male screw is formed into the hole 71 and screwing it with the cylindrical portion 19. The cylinder portion 19 also functions as a member that positions the image pickup device 2 in the optical path direction.

  The terminal board 9 is a flexible board, and its lower end is soldered to the board 7. Both ends of the coil of the exciting coil unit 43 are soldered to the upper end portion of the terminal board 9. Both end portions of the coil of the exciting coil unit 43 are led out from the back surface portion 11b side to the front surface portion 11a side through the opening portion 11d provided in the base member 1, and are soldered to the terminal board 9. A wiring connector (not shown) is attached to the back surface side of the substrate 7 and electrically connects the imaging device 2 and the coil of the exciting coil unit 42 to an external device.

  Next, an assembling method of the imaging unit A having such a configuration will be described. First, the filter member 3 and the drive device 4 are attached to the back surface portion 11b of the base member 1 (first attachment step: state shown in FIG. 4B). Thereafter, the partition plate 5 is attached to the base member 1 from the back surface portion 11b side of the base member 1 (second attachment step: state of FIG. 5). Thereafter, the imaging device 2 mounted on the substrate 7 is attached to the attachment portions 13a to 13d from the back surface portion 11b side of the base member 1 (third attachment step: state of FIG. 6). Subsequently, the substrate 7 is fixed to the base member 1 with the bolts 8.

  The lens barrel 6 may be fixed to the base member 1 either before or after each of these steps. As for the connection of the terminal plate 9 to the coil and the soldering to the substrate 7, both ends of the coil are led out from the holes 11d during the first mounting step, and the terminal plate 9 and the coil are connected to each other after each step. And soldering to the substrate 7 may be performed.

  In this assembling method, in the first to third attaching steps, the assembling workability is improved by sequentially assembling the filter member 3, the driving device 4, the partition plate 5, and the image pickup device 2 from the back surface portion 11b side of the base member 1. It can be improved.

  Next, in the imaging unit A having such a configuration, the filter member 3 having the optical filter portion 32 is configured to be movable between the first and second positions, so that the light received by the imaging element 2 is optically filtered. It is possible to select between the light transmitted through the unit 32 and the light that does not pass through, so that the photographing performance can be improved. In the present embodiment, since the optical filter unit 32 is an infrared cut filter, a color image is captured by interposing the optical filter unit 32 between the lens barrel 6 and the image sensor 2 during the daytime, and optical at night. The filter unit 32 can be retracted from between the lens barrel 6 and the image sensor 2 to capture a black and white image.

  Further, by attaching the filter member 3 and the image pickup device 2 to the common base member 1, they can be arranged more densely and the size can be reduced. In particular, since both the filter member and the imaging device 2 are arranged on the back surface portion 11b of the base member 1, further downsizing can be achieved. In addition, since the drive device 4 is also attached to the base member 1 and disposed on the back surface portion 11b of the base member 1, further miniaturization can be achieved.

  Further, by attaching the filter member 3 and the imaging element 2 to the base member 1 having the opening portion 11c that defines the optical path by mounting the lens barrel 6, the opening portion 11c, the lens barrel 6, the optical filter portion 32, and the image pickup are performed. The positioning accuracy with the element 2 depends on the accuracy of the base member 1, and the influence of the mounting accuracy of the imaging unit A is small, and the positioning accuracy can be improved.

<Second Embodiment>
In the imaging unit A of the first embodiment, when the filter member 3 is located at the second position, the filter member 3 includes the optical filter portion 32 between the lens barrel 6 and the imaging element 2. The whole structure is not interposed. Since the base material 31 of the filter member 3 is not interposed, the refractive index is different between the case where the filter member 3 is in the first position and the case where the filter member 3 is in the second position, and the focal position changes. Therefore, in the present embodiment, even when the filter member 3 is located at the first position, the focal position is maintained substantially constant by interposing a portion that does not function as an optical filter.

  FIG. 7 is a diagram illustrating a state in which the filter member 3 ′ and the driving device 4 are assembled to the back surface portion 11 b in the second embodiment, and corresponds to FIG. 4B in the first embodiment. This embodiment is different from the filter member 3 of the first embodiment only in the configuration of the protruding portion 14c, and the other configurations are the same.

  In FIG. 7, the filter member 3 ′ is different from the filter member 3 in the shape of the base material 31, has a transparent portion 35 that does not form an optical thin film and does not function as an optical filter. The filter member 3 ′ is rotatable from the position indicated by the solid line to the position indicated by the broken line with the attachment portion 15 as the rotation center. The protrusion 14c 'has a smaller width than the protrusion 14c in order to avoid interference with the filter member 3'.

  Among the positions of the filter member 3 ′ indicated by the broken line, the position on the right side in the drawing is such that one side of the filter member 3 is in contact with the stopper portion 17, and the opening 11 c of the base member 1 and the image sensor 2. Is the first position where the optical filter part 32 is interposed between the first position and the second position. When the filter member 3 ′ is located at the first position, the light received by the imaging device 2 is light that has passed through the optical filter portion 32.

  The position of the filter member 3 ′ indicated by the solid line is such that the other side portion of the filter member 3 ′ is in contact with the mounting portion 13 d and the transparent portion 35 is between the opening portion 11 c of the base member 1 and the imaging element 2. It is the 2nd position which intervened. When the filter member 3 ′ is located at the second position, the light received by the image sensor 2 is light that has passed through the transparent portion 35.

  Since the optical thin film forming the optical filter portion 32 and the base material 31 generally have a thickness difference of 10 to 200 times, the influence of the change in the refractive index is dominated by the thickness of the base material 31. is there. Therefore, by making the thickness of the entire base material 31 substantially uniform, or by making the thickness of the base material 31 substantially the same in at least the optical filter portion 32 and the transparent portion 35, the refractive index becomes substantially the same, and the focal position is filtered. Regardless of the position of the member 3 ′, it can be maintained substantially constant, and the captured image can have higher image quality.

<Third Embodiment>
Next, a configuration example of an imaging apparatus using the imaging unit A will be described. FIG. 8A is a block diagram of an image pickup apparatus B using the image pickup unit A. The imaging device B can be applied to, for example, a camera of a mobile phone, an in-vehicle camera, a surveillance camera, and the like.

  The imaging apparatus B includes a CPU 101, a display 102, an operation unit 103, a ROM 104, a RAM 105, an A / D conversion circuit 106, and an image processing circuit 107. The CPU 101 executes a program stored in the ROM 104 and performs overall control of the image pickup apparatus B including control of the image pickup element 2 and control of the excitation coil unit 43 of the drive device 4 (coil energization control). The display 102 displays an image captured by the image sensor 2. The operation unit 103 is a selection button for selecting whether the shutter button and the position of the filter member 3 are automatically switched (automatic mode) or manual switching (manual mode), and selects the position of the filter member 3 in the manual mode. Including a selection button and the like.

  The ROM 104 stores programs executed by the CPU 101 and fixed data. The RAM 105 stores variable data such as image data picked up by the image pickup device 2 and calculation results of the CPU 101. The ROM 104 and the RAM 105 may be other storage means.

  The A / D conversion circuit 106 converts an electrical signal indicating an image output from the image sensor 2 from an analog image signal to a digital image signal. The image processing circuit 107 adjusts color balance and the like for the digital image signal converted by the A / D conversion circuit 106. The drive circuit 108 supplies a drive current to the coils of the exciting coil unit 43 based on a control signal from the CPU 101.

  Next, an example of movement control of the filter member 3 (or the filter member 3 ′, hereinafter the same) by the CPU 101 will be described. In the case of the manual mode, in response to a user operation on the selection button of the operation unit 103, the drive circuit 108 is moved to move the filter member 3 to the position (first and second positions) of the filter member 3 selected by the user. Output a control signal.

  In the automatic mode, when the brightness of the digital image signal of the image captured by the image sensor 2 output from the image processing circuit 107 is brighter than a predetermined threshold, the filter member 3 is in the first position, and the brightness is dark Outputs a control signal to the drive circuit 108 to move the filter member 3 to the second position. With this control, when the shooting environment is bright, the imaging device 2 receives light that has passed through the optical filter unit 32, and when the shooting environment is dark, the imaging device 2 receives light that does not pass through the optical filter unit 32. Thus, the position of the filter member 3 having the optical filter portion 32 can be automatically switched to a position according to the photographing environment. The luminance of the digital image signal can be, for example, an average value of the luminance of each pixel in the entire imaging range. Moreover, it is good also as an average value of the brightness | luminance of each pixel of a one part area | region within an imaging range.

  FIG. 8B shows a change in luminance of the digital image signal, a change in drive current supplied from the drive circuit 108 to the coil of the excitation coil unit 43, and a change in the position of the optical filter unit 32 in the automatic mode. It is a figure which shows an example.

  In the example of the figure, a case where the luminance of the digital image signal continuously changes from light → dark → light is shown. The polarity of the drive current is inverted between when the luminance of the digital image signal is darker than the threshold and when it is bright, and when it is dark, the filter member 3 moves to the second position, and when it is bright, it moves to the first position. Thus, the polarity is associated with the rotation direction of the filter member 3. In the example of the figure, when the luminance change of the digital image signal crosses the threshold value, it is output only for a certain time. As described above, it is sufficient to output the drive current only for a predetermined time due to the detent torque between the stator yoke 41 and the rotor magnet 42a.

  When the luminance of the digital image signal is darker than the threshold value, the optical filter unit 32 retracts from between the lens barrel 6 and the imaging element 2 by positioning the filter member 3 at the second position, and the digital image When the luminance of the signal is brighter than the threshold value, the filter member 3 is located at the first position, so that it is interposed between the lens barrel 6 and the image sensor 2.

It is a perspective view of imaging unit A concerning one embodiment of the present invention. 2 is an exploded perspective view of an imaging unit A. FIG. (A) is a perspective view of the rotor 42, and (b) is a rear view of the base member 1. (A) is a figure which shows the state which assembled | attached the filter member 3 and the drive device 4, (b) is a figure which shows the state which assembled | attached the filter member 3 and the drive device 4 to the back surface part 11b. 2 is a perspective view showing a state in which a partition plate 5 is mounted on a base member 1. FIG. The state which attached the image pick-up element 2 to the attaching parts 13a thru | or 13d from the state of FIG. 5 is shown. In 2nd Embodiment, it is a figure which shows the state which assembled | attached the filter member 3 'and the drive device 4 to the back surface part 11b. (A) is a block diagram of an image pickup apparatus B using the image pickup unit A, (b) is a change in luminance of the digital image signal in the automatic mode, and a drive current supplied from the drive circuit 108 to the coil of the exciting coil unit 43. It is a figure which shows the example of the change of and the change of the position of the optical filter part 32. FIG.

Explanation of symbols

A Imaging unit 1 Base member 2 Imaging element 3 Filter member 32 Optical filter portion 11c Openings 13a to 13d Mounting portion 15 Mounting portion

Claims (14)

A base member having an opening;
An image sensor that receives light passing through the opening and converts the light into an electrical signal;
A filter member having an optical filter portion interposed between the opening and the imaging device;
In an imaging unit comprising
The base member is
An image sensor mounting portion to which the image sensor is mounted;
Between a first position where the optical filter portion is interposed between the opening and the imaging device, and a second position where the optical filter portion is not interposed between the opening and the imaging device. And a filter member mounting portion to which the filter member is mounted so that the filter member is movable,
An imaging unit comprising: Drive means for moving the filter member between the first position and the second position;
The imaging unit according to claim 1, wherein the base member includes a driving unit mounting portion to which the driving unit is mounted. The base member has a front part and a back part opposite to the front part,
The opening penetrates between the front part and the back part,
The imaging unit according to claim 2, wherein the imaging element mounting portion, the filter member mounting portion, and the driving means mounting portion are provided on the back surface portion.   4. The apparatus according to claim 1, further comprising a partition plate that is interposed between the image sensor and the filter member and partitions a movement space of the filter member and a space in which the image sensor is disposed. The imaging unit according to item. The filter member is
A resin substrate;
An optical thin film that is laminated on the resin substrate and forms the optical filter portion;
The imaging unit according to any one of claims 1 to 4, further comprising: The filter member includes a transparent portion that does not function as an optical filter,
6. The imaging unit according to claim 1, wherein the second position is a position where the transparent portion is interposed between the opening and the imaging element.   The imaging unit according to claim 1, wherein the optical filter unit is a filter that adjusts transmission of light in an infrared region.   The imaging unit according to claim 1, wherein the optical filter unit is a filter that adjusts transmission of light in a visible region. The driving means includes
The imaging unit according to claim 2, wherein the imaging unit is located on a side of the imaging device when the imaging unit is viewed in the opening portion-the imaging device direction. The filter member mounting portion rotatably supports the filter member,
The filter member is provided so as to be rotatable between the first position and the second position with the filter member mounting portion as a rotation center.
The driving means includes
A rotor magnet composed of permanent magnets;
A connecting member for connecting the rotor magnet and the filter member;
A stator yoke having a portion surrounding the rotor magnet;
An exciting coil for exciting the stator yoke and rotating the rotor magnet;
The imaging unit according to claim 2, further comprising: The base member has a front part and a back part opposite to the front part,
The opening penetrates between the front part and the back part,
The imaging element mounting portion and the filter member mounting portion are provided on the back surface portion,
The imaging unit according to claim 1, further comprising a lens barrel attached to the opening on the front side. In the assembly method of the imaging unit,
The imaging unit is
A base member having a front part, a back part opposite to the front part, and an opening penetrating between the front part and the back part;
An image sensor that receives light passing through the opening and converts the light into an electrical signal;
An image sensor mounting portion that protrudes from the back surface portion of the base member and to which the image sensor is mounted;
A first position where the optical filter portion is interposed between the opening portion and the imaging element; and the optical filter portion is the first position where the optical filter portion is interposed between the opening portion and the imaging element. A filter member provided movably between a second position not interposed between the opening and the imaging element;
Drive means for moving the filter member between the first position and the second position;
A partition plate that is interposed between the imaging element and the filter member, and partitions the moving space of the filter member and the arrangement space of the imaging element;
The assembly method is as follows:
A first attachment step of attaching the filter member and the driving means to the back surface portion of the base member;
After the first attachment step, a second attachment step of attaching the partition plate to the base member from the back surface side of the base member;
After the second attachment step, a third attachment step of attaching the image sensor to the image sensor attachment portion from the back surface side of the base member;
An image pickup unit assembly method comprising: A base member having an opening;
An image sensor that receives light passing through the opening and converts the light into an electrical signal;
A filter member having an optical filter portion interposed between the opening and the imaging device;
In an imaging apparatus comprising:
The base member is
An image sensor mounting portion to which the image sensor is mounted;
Between a first position where the optical filter portion is interposed between the opening and the imaging device, and a second position where the optical filter portion is not interposed between the opening and the imaging device. A filter member mounting portion to which the filter member is mounted so that the filter member is movable,
Drive means for moving the filter member between the first position and the second position;
Control means for controlling the drive means based on the electrical signal output from the image sensor;
An imaging apparatus comprising: The base member has a front part and a back part opposite to the front part,
The opening penetrates between the front part and the back part,
The image pickup apparatus according to claim 13, wherein the image pickup device attachment portion and the filter member attachment portion are provided on the back surface portion.

Images