JP2014071434A - Filter switching device, iris device, and camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for reducing a space for filter switching for a filter switching device which switches optical filters by moving at least two filter units.SOLUTION: A filter switching device includes: two filter units 51, 52 having optical filters (54, 57) which can be disposed in an incident light path where incident light travels, and a support part supporting the two filter units 51, 57 movably, and also includes: movement driving means (5, 7) which switch the optical filters (54, 57) to be disposed in the incident light path by moving the two filter units 51, 52 so that the two filter units 51, 52 supported by the support part are shifted in position to each other through the movement.

Description

  The present invention relates to a filter switching device that switches an optical filter, and an aperture device and a camera including the same.

  Various cameras including a monitoring camera incorporate a diaphragm device that adjusts the amount of light incident from the outside (hereinafter also referred to as “incident light amount”). The diaphragm device adjusts (optimizes) the amount of incident light by changing the size of a diaphragm aperture present on the optical path of incident light. As a mechanism of the diaphragm device, there is one that adjusts the light amount by moving the diaphragm member. Specifically, a member using a pair of diaphragm blades as a diaphragm member is known (see, for example, Patent Document 1).

  In addition, an imaging device capable of color photography is incorporated in a day and night surveillance camera. In this type of surveillance camera, the shooting mode is switched between when the subject is bright and when the subject is dark. Specifically, the shooting mode is switched so that the color shooting mode is applied when shooting when the subject is bright, such as daytime, and the monochrome shooting mode is applied when shooting when the subject is dark, such as at night.

  Some of the monitoring cameras described above have a function of switching an optical filter in addition to a function of switching a shooting mode (see, for example, Patent Documents 1 and 2). Specifically, in the color photographing mode, the image is taken through the infrared cut filter, and in the monochrome photographing mode, the image is taken without the infrared cut filter or through another optical filter. For this reason, when photographing in the color photographing mode, light incident from the outside reaches the image sensor through the infrared cut filter. When shooting in the monochrome imaging mode, light incident from the outside reaches the imaging device without passing through the infrared cut filter or through the other optical filter.

  In a filter switching device used for a surveillance camera or the like, the optical filter is switched by changing the arrangement of the optical filter. For example, in Patent Document 1 described above, two optical filters are mounted side by side on a common filter support member, and the optical filter is switched by moving the filter support member in the direction in which the optical filters are aligned. Is disclosed. Patent Document 2 described above discloses a configuration in which an optical filter is supported by a filter support member and the optical filter is switched by moving the filter support member.

JP 2003-348398 A JP 2007-17594 A

  In recent years, there has been an increasing demand for higher resolution as surveillance cameras become more popular. In order to realize high resolution of the surveillance camera, it is necessary to increase the number of pixels of the image sensor used for this. However, simply increasing the number of pixels of the image sensor increases the size of the image sensor. Further, if the pixel size per pixel is reduced, it is not necessary to increase the size of the image sensor, but in that case, it is easily affected by noise. For this reason, in order to realize high resolution of the surveillance camera while suppressing the influence of noise, it is necessary to use an image sensor having a larger size than before. In such a case, the aperture device attached to the surveillance camera needs to ensure a large maximum aperture aperture according to the size of the image sensor.

However, if, for example, the configuration described in Patent Document 1 described above is adopted as a filter switching device including two optical filters, the following problems arise in increasing the resolution of the surveillance camera.
That is, the filter switching device described in Patent Document 1 employs a mechanism in which two optical filters are mounted side by side on a common filter support member, and the filter support member is moved in the direction in which the optical filters are aligned. For this reason, when the first optical filter is disposed in the aperture opening of the aperture device, it is necessary to dispose (retract) the second optical filter at a position shifted to one side from the aperture opening. Further, when the second optical filter is disposed in the aperture opening, it is necessary to dispose (retract) the first optical filter at a position shifted from the aperture opening to the other side. Accordingly, it is necessary to secure a space for arranging three optical filters side by side as a moving space necessary for switching the optical filters (hereinafter referred to as “filter switching space”). Therefore, the aperture device becomes large. In particular, if the maximum aperture diameter is secured to increase the resolution of the surveillance camera while suppressing the effects of noise described above, the size of the optical filter also increases accordingly, so there is more space for filter switching. The enlargement will increase the size of the diaphragm device.

  A main object of the present invention is to provide a technique capable of reducing a filter switching space in a filter switching device that switches an optical filter by moving at least two filter units.

The first aspect of the present invention is:
At least two filter units each having an optical filter that can be arranged in an incident optical path through which incident light passes;
By moving the two filter units so that the positions of the two filter units supported by the support portions are interchanged before and after the movement, including a support portion that movably supports the two filter units. Moving drive means for switching an optical filter disposed in the incident optical path;
A filter switching device comprising:

The second aspect of the present invention is:
The filter switching device according to the first aspect, wherein the support portion includes a support shaft that rotatably supports the two filter units.

The third aspect of the present invention is:
The filter switching device according to the first or second aspect, wherein the two filter units are rotatably supported with the support shaft as a common rotation center.

The fourth aspect of the present invention is:
The two filter units are formed in a substantially fan shape. The filter switching device according to any one of the first to third aspects.

According to a fifth aspect of the present invention,
The movement driving means includes a driving source and a driving force transmission mechanism that transmits a driving force of the driving source to the two filter units.
The driving force transmission mechanism is constituted by a gear transmission mechanism. The filter switching device according to any one of the first to fourth aspects.

The sixth aspect of the present invention is:
The gear transmission mechanism transmits the driving force of the driving source so as to move the two filter units in opposite directions by a gear train using a common driving gear. It is a filter switching apparatus as described in an aspect.

The seventh aspect of the present invention is
The filter switching device according to any one of the first to sixth aspects;
A diaphragm member that forms a diaphragm aperture through which the incident light passes;
With
An aperture device characterized in that an optical filter disposed in an incident optical path of incident light passing through the aperture opening can be switched, and the size of the aperture opening formed by the aperture member can be adjusted.

The eighth aspect of the present invention is
In the throttling device according to the seventh aspect,
The diaphragm member is constituted by a pair of diaphragm blades, the filter switching device and the pair of diaphragm blades are respectively mounted on a base member, and the pair of diaphragm blades and the two filters in the thickness direction of the base member A diaphragm device characterized in that a partition plate is provided between the units.

The ninth aspect of the present invention provides
The filter switching device according to any one of the first to sixth aspects;
A photoelectric conversion element that converts incident light incident through the optical filter disposed in the incident optical path into an electrical signal;
It is a camera characterized by providing.

  ADVANTAGE OF THE INVENTION According to this invention, the filter switching space can be reduced in the filter switching apparatus which switches an optical filter by moving at least two filter units.

It is a figure which shows the structural example of the camera to which this invention is applied. It is an assembly perspective view when the diaphragm | throttle device concerning embodiment of this invention is seen from diagonally upward. It is an assembly perspective view when the diaphragm | throttle device which concerns on embodiment of this invention is seen from diagonally downward. It is a disassembled perspective view when the diaphragm | throttle device concerning embodiment of this invention is seen from diagonally upward. It is a disassembled perspective view when the diaphragm | throttle device concerning embodiment of this invention is seen from diagonally downward. It is a disassembled perspective view which shows the structure of a filter switching mechanism and a filter drive part. It is FIG. (1) explaining the meshing relationship of the gear train of a filter switching mechanism. It is FIG. (2) explaining the meshing relationship of the gear train of a filter switching mechanism. It is FIG. (1) explaining a filter switching operation | movement. It is FIG. (2) explaining a filter switching operation | movement.

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

<Camera configuration>
First, the configuration of the camera will be described.
1A and 1B show an example of the configuration of a camera to which the present invention is applied. FIG. 1A is an external view of the entire camera, and FIG. 1B is a schematic view inside a lens barrel. The illustrated camera 100 is, for example, a surveillance camera installed on a ceiling portion (or wall, pillar, etc.) of a building for crime prevention purposes. The camera 100 includes a mounting base 101 and a camera body 102. The mounting base 101 is structured to be fixed to a ceiling portion of a building by screwing, for example.

  The camera body 102 includes a lens barrel portion 103 and an objective lens 104. An optical system including the objective lens 104 is incorporated in the lens barrel portion 103. The objective lens 104 is attached to the tip of the lens barrel 103. Further, the camera body 102 incorporates the diaphragm device 1 as one functional part of the optical system and the image sensor 105. The diaphragm device 1 forms a diaphragm aperture in the course of light (hereinafter referred to as “incident light path”) of light incident on the lens barrel 103 (hereinafter referred to as “incident light path”), and adjusts the size of the diaphragm aperture. By doing so, the amount of incident light is adjusted. The configuration of the diaphragm device 1 will be described in detail later.

  The image sensor 105 is an image sensor that can perform color photography, and is configured by, for example, a CCD (Charge Coupled Device) image sensor, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, or the like. The imaging element 105 has an imaging surface formed by arranging a plurality of (many) pixels in a matrix, for example. The imaging element 105 is incorporated as an example of a photoelectric conversion element that converts incident light incident on the imaging surface through the aperture opening of the aperture stop device 1 into an electrical signal.

  In addition, this invention is applicable not only to the camera 100 illustrated here but the camera of the other structure provided with the aperture_diaphragm | restriction apparatus 1. FIG. In addition, various changes can be made to the configuration of the optical system, such as the type, number, and arrangement of lenses and the arrangement of the diaphragm 1.

<Configuration of diaphragm device>
Next, the configuration of the diaphragm device will be described.
FIG. 2 is an assembled perspective view of the diaphragm device according to the embodiment of the present invention when viewed obliquely from above (however, the cover member is not shown), and FIG. 3 is when the diaphragm device is viewed from diagonally below. FIG. FIG. 4 is an exploded perspective view when the diaphragm device according to the embodiment of the present invention is viewed obliquely from above, and FIG. 5 is an exploded perspective view when the diaphragm device is viewed from diagonally below. Here, one side in the thickness direction of the diaphragm device is the upper side, and the other is the lower side. However, when the diaphragm device is actually attached to the camera, the direction of up, down, left, and right changes depending on the attachment method.

  The illustrated diaphragm device 1 generally includes a diaphragm substrate 2, a pair (two) of diaphragm blades 3, 4, a filter switching mechanism 5, a diaphragm driving unit 6, a filter driving unit 7, and a partition plate 8. The cover member 9 is provided.

  The diaphragm substrate 2 is a member (base member) serving as a base for attaching each member constituting the diaphragm device 1. The pair of diaphragm blades 3 and 4 are provided as an example of a diaphragm member that forms a diaphragm aperture through which incident light passes. The pair of diaphragm blades 3 and 4 form a diaphragm aperture in a state where they overlap each other. When the size of the aperture is relatively large, the amount of light passing therethrough (incident light quantity) is relatively increased, and when the size of the aperture is relatively small, the amount of light passing therethrough Decreases relatively. The filter switching mechanism 5 is a mechanism for switching the optical filter. The diaphragm drive unit 6 serves as a drive source for relatively moving the pair of diaphragm blades 3 and 4 in order to adjust the size of the diaphragm opening. The filter drive unit 7 is a drive source for the filter switching mechanism 5. Hereinafter, the configuration of each unit will be described in more detail.

  The diaphragm substrate 2 is made of, for example, resin. As shown in FIG. 5, the diaphragm substrate 2 is formed with an arc-shaped communication hole 10 and an opening 11 through which incident light passes. The opening 11 is formed in a circular shape so as to penetrate in the thickness direction of the diaphragm substrate 2. Further, four pins 12 a, 12 b, 12 c, 12 d and four support shafts 14, 15, 16, 17 are provided on the lower surface side of the diaphragm substrate 2. The four pins 12 a, 12 b, 12 c, 12 d are used when the diaphragm blades 3, 4 and the partition plate 8 are attached to the diaphragm substrate 2. The four support shafts 14, 15, 16, and 17 are used when components (described later) of the filter switching mechanism 5 are attached to the diaphragm substrate 2. Further, claw portions 18,... Are provided at four locations on the outer peripheral portion of the diaphragm substrate 2. The claw portions 18 are used when the cover member 9 is attached to the diaphragm substrate 2.

  The pair of diaphragm blades 3 and 4 is configured by using a material having conductivity by coating the surface of a plate material made of polyethylene terephthalate with a carbon film, for example. Each of the diaphragm blades 3 and 4 is formed in a thin plate shape as a whole.

  One aperture blade 3 is provided with one hole portion 21, three guide grooves 22 a, 22 b, 22 c, and one engagement hole 23. The hole portion 21 has a planar shape in which a part of the outer periphery of a perfect circle or a circular shape close thereto is cut out into a substantially V shape. An ND (Neutral Density) filter (not shown) is attached to a part of the hole 21 (V-shaped notch). The three guide grooves 22 a, 22 b, and 22 c are formed in parallel with each other along the longitudinal direction of the diaphragm blade 3. Of the three guide grooves 22a, 22b, and 22c, the two guide grooves 22a and 22b are formed on the same straight line. The remaining guide groove 22c is formed on the opposite edge of the hole 21 with respect to the two guide grooves 22a and 22b. The engagement hole 23 is formed on an extension line of the two guide grooves 22a and 22b. The engagement hole 23 is formed in a long hole shape in plan view along the short direction of the diaphragm blade 3.

  The other aperture blade 4 is provided with one hole 24, three guide grooves 25a, 25b, 25c, and one engagement hole 26. The hole 24 has a planar shape in which a part of a perfect circle or a circular shape close thereto is cut into a V shape. An ND filter (not shown) is attached to part of the hole 24 (V-shaped notch). The hole 24 forms an aperture opening by overlapping with the hole 21 described above. The three guide grooves 25a, 25b, and 25c are formed in parallel to each other along the longitudinal direction of the diaphragm blades 4. Of the three guide grooves 25a, 25b, 25c, the two guide grooves 25a, 25b are formed on the same straight line. The remaining one guide groove 25c is formed on the opposite edge of the two guide grooves 25a and 25b with the hole 24 therebetween. The engagement hole 26 is formed on an extension line of the two guide grooves 25a and 25b. The engagement hole 26 is formed in a long hole shape in plan view along the short direction of the aperture blade 4.

  The configurations of the filter switching mechanism 5 and the filter driving unit 7 will be described in detail later.

  The diaphragm drive unit 6 is configured by using a diaphragm operation unit 31 connected to a pair of diaphragm blades 3, 4, a yoke 33, a relay substrate 34, a magnetic body (not shown), and a coil (not shown). Has been.

  The aperture operation unit 31 includes a rectangular magnet (permanent magnet) 35 having a rectangular parallelepiped structure, and an arm member 36. The magnet 35 is attached to the arm member 36 in a fixed state.

  The arm member 36 is obtained by integral molding of resin, for example. Shafts 37a and 37b are provided above and below the arm member 36, respectively. These shafts 37 a and 37 b are provided on the same shaft that is the rotation center of the diaphragm operating unit 31. In addition to the shafts 37a and 37b described above, the arm member 35 is integrally formed with a magnet holder portion 38 and a pair of arm portions 39a and 39b. The arm portions 39a and 39b are formed so as to extend from the magnet holder portion 38 to one and the other. Each arm part 39a, 39b is formed in a crank shape. Further, a claw portion 40a is formed at the distal end portion of one arm portion 39a, and a claw portion 40b is also formed at the distal end portion of the other arm portion 39b.

  The yoke 33 suppresses leakage of magnetic field lines to the outside. The yoke 33 is formed in a cylindrical shape. The yoke 33 accommodates a bobbin assembly (not shown) in a state in which the above-described diaphragm operating unit 31, a magnetic body (not shown), and a coil (not shown) are assembled. However, when the bobbin assembly is housed in the yoke 33, the arm portions 39 a and 39 b of the arm member 35 protrude from the yoke 33.

  The relay board 34 electrically connects a coil (not shown) wound around the bobbin assembly and a diaphragm control unit (not shown). The diaphragm controller rotates the diaphragm actuator 31 by energizing the coil when a predetermined condition is satisfied. The relay board 34 is configured by a circular printed wiring board corresponding to the diameter of the yoke 33.

  The partition plate 8 is formed in a thin plate shape. The partition plate 8 is configured using, for example, a material made conductive by covering the surface of a plate-shaped material made of polyethylene terephthalate with a carbon film, like the diaphragm blades 3 and 4 described above. The partition plate 8 is disposed between the diaphragm blades 3 and 4 and filter units 51 and 52 described later in the thickness direction of the diaphragm substrate 2.

  The partition plate 8 is formed with an opening 41, four through holes 42a, 42b, 42c, and 42d, and guide portions 43a and 43b. The opening 41 is formed in a circular shape so as to penetrate the partition plate 8. The opening 41 is arranged concentrically with the opening 11 of the diaphragm substrate 2 when the partition plate 8 is attached to the diaphragm substrate 2. The four through holes 42a, 42b, 42c, and 42d are fitted into four pins 12a, 12b, 12c, and 12d provided on the diaphragm substrate 2, respectively. The guides 43a and 43b are formed in a double arc shape. The guide portions 43a and 43b are formed so as to protrude downward. The guide portions 43a and 43b guide the rotational movement operation of the upper filter unit 51.

  The cover member 9 is obtained by integral molding of resin or the like, for example. The cover member 9 is attached to the lower surface side of the diaphragm substrate 2. At that time, the diaphragm blades 3, 4, the partition plate 8, filter units 51, 52 described later, and the like are accommodated between the diaphragm substrate 2 and the cover member 9. The cover member 9 is formed with an opening 44, four through holes 45 a, 45 b, 45 c, 45 d, guide portions 46 a, 46 b, and a relief hole 47. The opening 44 is formed in a circular shape so as to penetrate the cover member 9. The opening 44 is arranged concentrically with the opening 11 of the diaphragm substrate 2 when the cover member 9 is attached to the diaphragm substrate 2. The four through holes 45a, 45b, 45c, and 45d are fitted into four pins 12a, 12b, 12c, and 12d provided on the diaphragm substrate 2, respectively. The guides 46a and 46b are formed in a double arc shape. Each of the guide portions 46a and 46b is formed so as to protrude slightly upward. The guide portions 46 a and 46 b guide the rotational movement operation of the lower filter unit 52. The escape hole 47 is formed in an arc shape so as to penetrate the cover member 9. The escape hole 47 is for avoiding interference with a gear portion 66a described later. Further, four attachment pieces 48 with holes are formed on the outer peripheral portion of the cover member 9. Each of the attachment pieces 48,... Is hooked and fixed to the claw portions 18,.

<Configuration of filter switching mechanism>
Next, the configuration of the filter switching mechanism 5 including the filter driving unit 7 will be described.
The filter switching mechanism 5 is roughly composed of the above-described filter driving unit 7, two filter units 51 and 52, and a driving force transmission mechanism 53 that transmits the driving force of the filter driving unit 7 to the two filter units 51 and 52. It is the structure provided with. Among these, the filter switching mechanism 5 constitutes a main part of the “filter switching device”. Further, the filter driving unit 7 and the driving force transmission mechanism 53 constitute a “movement driving unit” together with a “supporting unit” described later.

The two filter units 51 and 52 have basically the same configuration. For this reason, only the configuration of one (upper) filter unit 51 will be described in detail here.
The filter unit 51 includes an optical filter 54 and a filter support member 55 that supports the optical filter 54. The optical filter 54 is configured based on, for example, a square (square in the illustrated example) glass substrate. The shape of the optical filter 54 is not limited to a quadrangle, and may be, for example, a circle or a polygon other than a quadrangle.

  The filter support member 55 is obtained, for example, by integral molding of resin. The filter support member 55 is formed in a substantially fan shape as a whole. A circular opening 56 is formed in the filter support member 55 so as to penetrate therethrough. The opening 56 is for passing incident light to be filtered. For this reason, the optical filter 54 is attached in a state of closing the opening 56. The optical filter 54 is fixed to one surface (upper surface in the illustrated example) of the filter support member 55 using, for example, an adhesive. Similarly, the other filter unit 52 is configured using an optical filter 57 and a filter support member 58 that supports the optical filter 57, and an opening 59 is formed in the filter support member 58.

  Various combinations of the optical filters 54 and 57 used in the two filter units 51 and 52 are conceivable. Here, as an example, one optical filter 54 is configured by an infrared cut filter, and the other optical filter 57 is configured by a dummy filter. doing. The infrared cut filter is a filter that cuts infrared light from incident light. The dummy filter is a filter (optical path length correction filter) used for optical path length correction. Specifically, the dummy filter has an optical path length when an optical filter (infrared cut filter in this embodiment) used in combination with this is disposed in the incident optical path, and an optical path length when the dummy filter is disposed in the incident optical path. The optical path length is corrected so that is equal.

  The driving force transmission mechanism 53 is constituted by a gear transmission mechanism (hereinafter referred to as “gear transmission mechanism 53”). The gear transmission mechanism 53 is configured substantially using six gears. Specifically, the gear transmission mechanism 53 uses two gear members 61, 62 having gear portions 61a, 62a, three gears 63, 64, 65, and a rotating member 66 having a gear portion 66a. It is configured.

  The two gear members 61 and 62 are each formed in a substantially sector shape. The gear portion 61 a is formed on the arc portion of the gear member 61, and the gear portion 62 a is formed on the arc portion of the gear member 62. The gear member 61 is fixed to the filter unit 51, and the gear member 62 is fixed to the filter unit 52. Among these, the gear unit 61 is attached to the filter support member 55 so as to face the same side as the optical filter 54 with respect to the filter unit 51. Similarly, a gear member 62 is attached to the filter support member 58 so as to face the same side as the optical filter 57 with respect to the filter unit 52. The filter unit 51 and the gear member 61 are assembled with a common (concentric) mounting hole 67. Similarly, the filter unit 52 and the gear member 62 are assembled with a common (concentric) mounting hole 68. ing.

  The three gears 63, 64, 65 are each constituted by a spur gear. Of these, the two gears 63 and 64 transmit the rotational driving force of the rotating member 66 to the gear member 61, and the gear 65 transmits the rotational driving force of the rotating member 66 to the gear member 62. .

  The rotating member 66 constitutes a filter operating part 71 together with a magnet (permanent magnet) 70 assembled thereto. The rotating member 66 is obtained by integral molding of resin, for example. The gear portion 66a is formed in an arc shape. On the top and bottom of the rotating member 66, shafts 72a and 72b are provided, respectively. These shafts 72 a and 72 b are provided on the same shaft that serves as the rotation center of the filter operating unit 71. Further, in addition to the gear portion 66a and the shafts 72a and 72b described above, a magnet holder portion 73 and an arm portion 74 are integrally formed on the rotating member 66. The arm portion 74 extends in an L shape from the magnet holder portion 73 to one side, and the above-described gear portion 66a is formed at the extended end. The arm portion 74 is connected to the middle portion of the arc of the gear portion 66a. The magnet 70 is composed of a rectangular permanent magnet having a rectangular parallelepiped structure, like the magnet 35 described above. The reason for using such a square magnet is that it is advantageous in terms of cost and ease of processing as compared with the case of using a cylindrical magnet. However, in carrying out the present invention, the shape of the magnet is not limited to a specific shape. The magnet 70 is assembled to the magnet holder 73 in a fixed state. In this assembled state, a virtual axis connecting the upper and lower shafts 72 a and 72 b passes through the center of the magnet 70.

  The yoke 75 that constitutes the filter driving unit 7 suppresses leakage of magnetic lines of force to the outside. The yoke 75 is formed in a cylindrical shape. As shown in FIG. 6, the filter drive unit 7 is mounted on the bobbin 77 so as to sandwich a bobbin 77 made of an insulating material such as resin, a coil 78 wound around the bobbin 77, and an upper portion of the coil 78. The supporting member 79 is used. The rotating member 66 described above is mounted on the bobbin 77 together with the magnet 70 assembled thereto. At that time, by inserting the upper shaft 72a of the rotating member 66 into the hole 79a of the support member 79 and inserting the lower shaft 72b into a hole (not shown) provided in the bottom plate portion of the bobbin 77, The rotating member 66 is rotatably supported. The yoke 75 accommodates a bobbin assembly including a rotating member 66, a magnet 70, a bobbin 77, a coil 78, a support member 79, and the like. However, when the bobbin assembly is housed in the yoke 75, the arm portion 74 and the gear portion 66 a of the rotating member 66 protrude from the yoke 75.

  The relay board 76 electrically connects a coil 78 wound around the bobbin assembly and a filter control unit (not shown). The filter control unit rotates the filter operating unit 71 by energizing the coil 78 when a predetermined condition is satisfied. The relay board 76 is formed of a circular printed wiring board corresponding to the diameter of the yoke 75.

<Explanation of component mounting state>
Then, the attachment state of the component of the expansion apparatus 1 is demonstrated.

First, the attachment state of the pair of diaphragm blades 3 and 4 with respect to the diaphragm substrate 2 will be described.
For the diaphragm blade 3, the guide grooves 22 a, 22 b, 22 c of the diaphragm blade 3 are fitted into pins 12 a, 12 c, 12 d provided on the lower surface side of the diaphragm substrate 2. Further, the claw portion 40a of the arm portion 39a of the arm member 36 is inserted into the engagement hole 23 of the aperture blade 3 and engaged therewith. On the other hand, for the diaphragm blade 4, the guide grooves 25 a, 25 b, 25 c of the diaphragm blade 4 are fitted into the pins 12 a, 12 b, 12 c provided on the lower surface side of the diaphragm substrate 2. Further, the claw portion 40b of the arm portion 39b of the arm member 36 is inserted into the engagement hole 26 of the aperture blade 4 and engaged therewith.

Next, the attachment state of the partition plate 8 to the diaphragm substrate 2 will be described.
The partition plate 8 is attached so as to cover the diaphragm plate 3 with the pair of diaphragm blades 3 and 4 attached to the diaphragm substrate 2 as described above. At this time, the four through holes 42a, 42b, 42c, and 42d of the partition plate 8 are fitted into the four pins 12a, 12b, 12c, and 12d of the diaphragm substrate 2.

Next, the attachment state of the filter switching mechanism 5 to the diaphragm substrate 2 will be described.
First, for the filter drive unit 7, the yoke 75 that houses the rotating member 66, the magnet 70, and the like described above is mounted on the upper surface side of the diaphragm substrate 2. At this time, the arm portion 74 and the gear portion 66a of the rotating member 66 are projected to the lower surface side of the diaphragm substrate 2 through the communication hole 10 (FIG. 5) formed in the diaphragm substrate 2.

  Regarding the gear train of the filter switching mechanism 5, the gear 63 is attached to the support shaft 14 of the diaphragm substrate 2, the gear 64 is attached to the support shaft 15 of the diaphragm substrate 2, and the gear 65 is attached to the support shaft 16 of the diaphragm substrate 2. Further, the mounting hole 67 of the filter unit 51 and the mounting hole 68 of the filter unit 52 are fitted into the support shaft 17 of the diaphragm substrate 2 in order. As a result, the two filter units 51 and 52 are rotatably supported with the support shaft 17 as a common rotation center. Further, the meshing relationship of the gear train is as follows. That is, as shown in FIG. 7, the two gears 63 and 64 are disposed so as to mesh with each other. Further, the gear 63 is arranged to mesh with the gear portion 61 a of the gear member 61, and the gear 64 is arranged to mesh with the gear portion 66 a of the rotating member 66. The gear 65 is disposed so as to mesh with both the gear portion 62 a of the gear member 62 and the gear portion 66 a of the rotating member 66. In this gear train, as shown in FIG. 8, one of gears 63 and 64 (gear 64) meshed with a gear member 61 attached to the filter unit 51 and a gear 65 meshed with a gear member 62 attached to the filter unit 52 are provided. Both mesh with the gear portion 66a of the rotating member 66. Further, the gear 64 and the gear 65 are arranged with their positions shifted in the tooth width direction (vertical direction) of the gear portion 66a. In this case, the gear portion 66 a of the rotating member 66 corresponds to a “common drive gear” for moving the two filter units 51 and 52.

Next, the attachment state of the cover member 9 to the diaphragm substrate 2 will be described.
The cover member 9 is attached to cover the filter switching mechanism 5 with the filter switching mechanism 5 attached to the diaphragm substrate 2 as described above. At this time, the four attachment pieces 48,... Of the cover member 9 are fastened to the four claws 18,. As a result, the pair of diaphragm blades 3 and 4, the two filter units 51 and 52, and the gear train attached thereto are interposed between the diaphragm substrate 2 and the cover member 9 in the thickness direction of the diaphragm substrate 2. It will be in the state. The aperture 11 of the diaphragm substrate 2, the aperture 41 of the separator 8, and the aperture 44 of the cover member 9 are arranged concentrically with respect to the optical axis of the incident optical path, and the pair of aperture blades 3 , 4 are also concentrically arranged. Furthermore, in a state before driving the filter driving unit 7, one of the two filter units 51 and 52 is disposed in the incident optical path.

  Next, the operation of the diaphragm device 1 will be described. The operation of the aperture device 1 includes an aperture adjustment operation and a filter switching operation. Hereinafter, each operation will be described in order.

<Description of aperture adjustment operation>
First, the aperture adjustment operation will be described. The diaphragm adjusting operation is an operation for changing the size of the diaphragm opening formed by the pair of diaphragm blades 3 and 4. More specifically, the diaphragm adjustment operation refers to an operation of adjusting the size of the diaphragm opening by relatively moving the pair of diaphragm blades 3 and 4. The operation of adjusting the size of the aperture opening in the diaphragm device 1 is substantially the same as the operation of adjusting the amount of incident light in a monitoring camera or the like equipped with the diaphragm device 1.

  When the size of the aperture opening is actually adjusted by the aperture device 1, a magnetic field is formed by energizing a coil included in the aperture drive unit 6. Then, the pair of diaphragm blades 3 and 4 moves simultaneously in the longitudinal direction of the diaphragm substrate 2 in accordance with the direction and strength of the magnetic field formed by energizing the coil. At this time, the direction in which one diaphragm blade 3 moves and the direction in which the other diaphragm blade 4 moves are opposite to each other. When the pair of diaphragm blades 3 and 4 are relatively moved in this manner, the size of the diaphragm aperture formed by the overlap of the diaphragm blades 3 and 4 changes. For this reason, the size of the aperture opening can be adjusted by driving the aperture drive unit 6.

<Description of filter switching operation>
Next, the filter switching operation will be described.
The filter switching operation refers to an operation of switching the optical filters (54, 57) arranged in the incident optical path. More specifically, the filter switching operation includes a first arrangement state in which one optical filter 54 is arranged in the incident optical path passing through the aperture opening and a first arrangement state in which the other optical filter 57 is arranged in the incident optical path. The operation of switching the arrangement of the optical filters 54 and 57 between the two arrangement states. In this switching operation, when the optical filter 54 is disposed in the incident optical path, the optical filter 57 is retracted from the incident optical path. When the optical filter 57 is disposed in the incident optical path, the optical filter 54 is retracted from the incident optical path. It becomes a state.

  When the arrangement state of the optical filters 54 and 57 is actually switched by the diaphragm device 1, a magnetic field is formed by energizing the coil 78 included in the filter driving unit 7. Then, the rotating member 66 rotates according to the direction and strength of the magnetic field formed by energizing the coil 78, and the rotational driving force is transmitted to the filter units 51 and 52 via the gear transmission mechanism 53. . Specifically, the rotational driving force of the rotating member 66 is transmitted to the filter unit 51 via the two gears 63 and 64 and the gear member 61. The rotational driving force of the rotating member 66 is also transmitted to the filter unit 52 through the gear 65 and the gear member 62. At this time, the gear 63 that meshes with the gear portion 61 a of the gear member 61 and the gear 65 that meshes with the gear portion 62 a of the gear member 62 rotate in opposite directions due to the change of the rotation direction due to the intervention of the gear 64. Therefore, the two filter units 51 and 52 rotate and move in directions opposite to each other around the support shaft 17. Therefore, the support shaft 17 corresponds to a “support portion” that movably supports the two filter units 51 and 52. The support shaft 17 supports the two filter units 51 and 52 so as to be movable separately. The “separate body” described here is a synonym of “integral”. That is, in the state where the mounting holes 67 and 68 of the filter units 51 and 52 are respectively inserted into the common support shaft 17, the filter units 51 and 52 can be individually rotated and moved. It can be moved by the body. "

  Here, in the stage before the movement, as shown in FIGS. 9A and 9B, the optical filter 54 of the filter unit 51 is disposed at the aperture opening 80 (assuming the fully opened state in the example), and the filter Assume that the optical filter 57 of the unit 52 has been retracted from the aperture opening 80. The aperture 80 is an incident optical path for incident light passing therethrough. Then, in the stage after the movement, as shown in FIGS. 10A and 10B, the optical filter 54 of the filter unit 51 is retracted from the aperture opening 80, and the optical filter 57 of the filter unit 52 is disposed in the aperture opening 80. It will be in the state. That is, the positions of the two filter units 51 and 52 are interchanged before and after the movement. For this reason, the arrangement state of the optical filters 54 and 57 can be switched by driving the filter driving unit 7. Incidentally, the filter unit 51 moves while in contact with the guide portions 43a and 43b formed on the partition plate 8. The portions that actually contact the guide portions 43 a and 43 b become a part of the optical filter 54 outside the opening 56 (a surplus portion that does not substantially function as an optical filter). Similarly, the filter unit 52 moves while contacting the guide portions 46 a and 46 b formed on the cover member 9. Further, at an intermediate time point from the start to the end of the movement, the optical filters 54 and 57 of the two filter units 51 and 52 are overlapped with each other during the movement.

<Effect according to the embodiment>
According to the embodiment of the present invention, the following effects can be obtained.

  That is, since the configuration of switching the optical filters 54 and 57 disposed in the incident optical path by switching the positions of the two filter units 51 and 52 is adopted, the filter switching space is reduced as compared with the conventional configuration. can do. That is, if a configuration in which a filter support member in which two optical filters are arranged next to each other is moved as in the prior art is adopted, a space for substantially arranging three optical filters side by side is necessary as a filter switching space. become. On the other hand, in the configuration in which the position of the filter unit 51 having the optical filter 54 and the position of the filter unit 52 having the optical filter 57 are interchanged before and after the movement as in the present embodiment, the filter switching space is used. Substantially enough space is required for arranging the two optical filters 54 and 57 side by side. For this reason, the filter switching space can be reduced as compared with the conventional case. As a result, the diaphragm device 1 can be reduced in size. In particular, in order to increase the size of the image pickup device in order to cope with higher resolution of a monitoring camera or the like, and to ensure a large maximum diameter of the aperture opening in accordance with this, the aperture device 1 is not increased in size as much as possible. It becomes possible to enlarge the maximum diameter of the opening.

  In addition, conventionally, when an impact force is applied to the diaphragm substrate, the filter support member is always kept in one position using the magnetic force of the magnet so that the filter support member does not move (displace) inadvertently due to the impact force. Energized in the direction. For this reason, when the optical filter is switched by moving the filter support member, it is necessary to supply a certain level of operating voltage to the filter drive unit (such as a coil) in order to apply a moving force larger than the magnetic force to the filter support member.

  On the other hand, in the above embodiment, when an impact force is applied to the diaphragm substrate 2, the impact force acts as follows. That is, even if the impact force applied to the diaphragm substrate 2 acts on the one filter unit 51 in the direction of promoting the movement, for example, the movement is prevented on the other filter unit 52). Acts on direction. The reason is as follows. First, when an impact force is applied to the diaphragm substrate 2 along the movement direction of the diaphragm blades 3 and 4, the movement force acts on the filter units 51 and 52 in the rotation direction around the support shaft 17. At this time, each of the filter units 51 and 52 receives substantially the same magnitude of moving force in the same direction, but is prevented from moving in the same direction because the gears of the gear train are engaged with each other. For this reason, even if an impact force is applied to the diaphragm substrate 2, the movement of the filter units 51 and 52 is suppressed. Thereby, the magnetic force (biasing force) of the magnet mentioned above can be weakened. In some cases, desired impact resistance can be ensured without using the magnetic force of the magnet. As a result, the optical filter can be switched with a smaller operating voltage than in the prior art. In addition, it is possible to reduce power consumption while ensuring the necessary impact resistance.

In the above embodiment, since the two filter units 51 and 52 are rotatably supported around the common support shaft 17 as the center of rotation, the operation of each filter unit 51 and 52 becomes compact. For this reason, it can contribute to the minimization of the filter switching space.
Further, since each of the filter units 51 and 52 is formed in a substantially fan shape as a whole, almost no useless space is generated in the filter switching operation. For this reason, it is possible to switch the optical filter in the minimum necessary filter switching space.
Furthermore, since the structure which moves two filter units 51 and 52 using said gear transmission mechanism 53 is employ | adopted, the structure of a drive system becomes very compact.

  Moreover, in the said embodiment, the partition plate 8 is arrange | positioned between a pair of aperture blades 3 and 4 and the two filter units 51 and 52, and those positional interference (contact) is avoided. . For this reason, the diaphragm blades 3 and 4 and the filter units 51 and 52 can be disposed close to each other with the partition plate 8 interposed therebetween. On the other hand, when the partition plate 8 is not provided, in order to avoid interference between the aperture blades 3 and 4 and the filter units 51 and 52, it is necessary to arrange them far apart. Therefore, when the partition plate 8 is provided, the total thickness can be reduced as compared with the case where the partition plate 8 is not provided. In particular, when a single-focus lens or the like (so-called bright lens) is used in the optical system as the resolution of a monitoring camera or the like increases, a lens disposed on the front side (subject side) of the aperture opening of the aperture stop device 1 It is necessary to arrange the lenses arranged on the rear side close to each other. For this reason, in the diaphragm device 1, it is very effective to reduce the thickness of the vicinity of the diaphragm aperture interposed between these lenses.

<Modifications>
The technical scope of the present invention is not limited to the above-described embodiments, and includes various modifications and improvements as long as the specific effects obtained by the constituent elements of the invention and combinations thereof can be derived.

  For example, regarding the number of filter units provided in the filter switching device, at least two filter units are required to switch the optical filters arranged in the incident optical path. However, the present invention is not limited to two, and the configuration includes three or more filter units. Also good.

  In the above-described embodiment, the configuration in which the two filter units 51 and 52 are rotatably supported is adopted. However, the present invention is not limited to this. For example, although not shown, the two filter units are linearly moved. It is possible to adopt a configuration that supports the above. However, in order to simplify the support structure for movement, it is preferable to adopt a support structure capable of rotational movement.

  Alternatively, the filter support member 55 and the gear member 61 may be formed as an integral structure by forming them integrally with resin instead of being separate members. This also applies to the filter support member 58 and the gear member 62.

  The combination of optical filters to be switched is not limited to a combination of different types of optical filters, but may be a combination of optical filters of the same type (however, the respective optical characteristics are different).

  Moreover, in the said embodiment, although the filter unit is comprised by the optical filter and the filter support member which supports this, not only this but the part which functions as an optical filter, and the part which functions as a filter support member It is also possible to integrally form the same material (glass or the like).

  Further, the driving force transmission mechanism is not limited to the gear transmission mechanism 53 described above, and may be a mechanism that transmits the driving force using a pulley or a timing belt, for example.

DESCRIPTION OF SYMBOLS 1 ... Diaphragm apparatus 2 ... Diaphragm board 3, 4 ... Diaphragm blade 5 ... Filter switching mechanism 8 ... Partition plate 17 ... Support shaft 51, 52 ... Filter unit 54, 57 ... Optical filter 55, 58 ... Filter support member 53 ... Gear transmission Mechanism 80 ... Aperture aperture 100 ... Camera 105 ... Image sensor

Claims (9)

At least two filter units each having an optical filter that can be arranged in an incident optical path through which incident light passes;
By moving the two filter units so that the positions of the two filter units supported by the support portions are interchanged before and after the movement, including a support portion that movably supports the two filter units. Moving drive means for switching an optical filter disposed in the incident optical path;
A filter switching device comprising: The filter switching device according to claim 1, wherein the support portion includes a support shaft that supports the two filter units so as to be rotatable. The filter switching device according to claim 1 or 2, wherein the two filter units are supported so as to be able to rotate and move with the support shaft as a common rotation center. The filter switching device according to any one of claims 1 to 3, wherein the two filter units are formed in a substantially fan shape. The movement driving means includes a driving source and a driving force transmission mechanism that transmits a driving force of the driving source to the two filter units.
The filter switching device according to any one of claims 1 to 4, wherein the driving force transmission mechanism includes a gear transmission mechanism. The gear transmission mechanism transmits the driving force of the driving source so as to move the two filter units in opposite directions by a gear train using a common driving gear. The filter switching device as described. A filter switching device according to any one of claims 1 to 6;
A diaphragm member that forms a diaphragm aperture through which the incident light passes;
With
An aperture device characterized in that an optical filter disposed in an incident optical path of incident light passing through the aperture opening can be switched, and the size of the aperture opening formed by the aperture member can be adjusted. The diaphragm device according to claim 7,
The diaphragm member is constituted by a pair of diaphragm blades, the filter switching device and the pair of diaphragm blades are respectively mounted on a base member, and the pair of diaphragm blades and the two filters in the thickness direction of the base member A diaphragm device characterized in that a partition plate is provided between the unit and the unit. A filter switching device according to any one of claims 1 to 6;
A photoelectric conversion element that converts incident light incident through the optical filter disposed in the incident optical path into an electrical signal;
A camera comprising:

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