JP2007017594A - Diaphragm device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the size and weight of a diaphragm having an optical filter that is freely inserted into an optical path or removed therefrom and to attach the diaphragm easily to the lens barrel of a CCTV camera. <P>SOLUTION: The diaphragm device includes: a diaphragm substrate 10 having an opening 10a forming the optical path; diaphragm vanes 12 and 13 disposed on one face of the diaphragm substrate and used to diaphragm the optical path by sliding along the face of the substrate; a diaphragm drive device 20 that drives the diaphragms; an optical filter 152; and a filter drive means for inserting the optical filter into the optical path or removing it therefrom. The optical filter 152 is formed in a thin film shape and is integrally attached to a separately produced filter frame 151 having a thin plate shape, and thereby the whole is constructed as an optical filter unit 15 having the thin plate shape. This optical filter unit is disposed on the one face of the diaphragm substrate to be freely slid along the diaphragm vanes. The filter frame is provided with a crank lever part 151b that is a part to be driven by the filter drive device. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical aperture device in which an optical filter such as an infrared cut filter is detachably mounted on an optical path, and in particular, an aperture assembled in a photographing device such as a CCTV (monitoring camera system) lens. It relates to the device.

  As a day-and-night monitoring camera system, color light is imaged on a color image sensor (CCD or CMOS, etc.) on the camera body during the daytime, and in the night, in addition to the light in the visible light region, near-red A system is known in which a monochrome image is captured by forming an image of light in an outer region and a monitoring image is displayed on a TV monitor (see, for example, Patent Document 1).

  During daytime shooting, this system places an infrared cut filter in front of the image sensor (inside the camera body or lens barrel) to perform color shooting based only on light in the visible light region, and also at night. At the time of photographing, the infrared cut filter is removed from the front of the image sensor, and monochrome photographing is performed based on light in a band from the infrared wavelength region to the visible wavelength region.

  FIGS. 8A and 8B are diagrams showing the configuration of a conventional CCTV camera provided with an infrared cut filter in the camera body.

  This CCTV camera includes a camera body 100A and a lens barrel 200A attached in front of the camera body 100A. An imaging element 130 and an infrared cut filter 110 are provided inside the camera body 100A. A diaphragm 210 is provided inside the lens barrel 200A.

  The infrared cut filter 110 in the camera body 100A is driven by a filter driving actuator 230 such as a motor provided in the camera body 100A, and is inserted into or removed from the optical path L in front of the image sensor 130. Or FIG. 8A shows a state where the infrared cut filter 110 is inserted on the optical path L, and FIG. 8B shows a state where the infrared cut filter 110 is removed from the optical path L. On the other hand, the aperture 210 in the lens barrel 200A is driven by an aperture driving actuator 220 such as a galvanometer provided in the lens barrel 200A to adjust the size of the aperture.

  In the state of FIG. 8A, since the infrared cut filter 110 is inserted on the optical path L, the light incident on the lens barrel 200A enters the camera body 100A via the diaphragm 210, and the infrared The light passes through the cut filter 110, reaches the image sensor 130, and is projected onto the image sensor 130 as a subject image. On the other hand, in the state of (b), since the infrared cut filter 110 is removed from the optical path L, the light incident on the lens barrel 200A enters the camera body 100A via the stop 210, and the infrared cut. The light reaches the image sensor 130 directly without passing through the filter 110 and is projected as a subject image.

  FIGS. 9A and 9B are diagrams showing the configuration of another conventional CCTV camera provided with an infrared cut filter in a lens barrel.

  This CCTV camera is composed of a camera body 100B and a lens barrel 200B attached in front of the camera body 100B. The infrared cut filter 110 and the filter driving actuator 230 are different from those of the conventional example of FIG. It is provided inside the lens barrel 200B, not inside. The image sensor 130 and the aperture 210 are the same as in the example of FIG.

  In this CCTV camera, a dummy filter 111 is provided adjacent to the infrared cut filter 110. This dummy filter 111 is made of a light-transmitting parallel flat plate having substantially the same thickness as the infrared cut filter 110, and has an optical path length when the infrared cut filter 110 is on the optical path L and when it is not. This is to compensate for the difference and to prevent the image sensor 130 from being out of focus due to the difference in optical path length.

  Therefore, the infrared cut filter 110 and the dummy filter 111 are attached to the same holder (not shown). By driving the holder by the filter driving actuator 230, either the infrared cut filter 110 or the dummy filter 111 is used. Is arranged on the optical path L.

In addition, since the conventional infrared cut filter is relatively thick (0.5 mm or more), in the CCTV camera described in Patent Document 1, a diaphragm blade is placed on one plate surface side of a diaphragm substrate (not shown). If an infrared cut filter is disposed on the other plate surface side of the diaphragm substrate, a diaphragm device that is integrally provided with an infrared cut filter is constructed while avoiding the complexity of the configuration of the diaphragm portion. Yes.
JP 2002-189238 A

  By the way, in the conventional CCTV camera of FIG. 8, the infrared cut filter 110 is arranged inside the camera body 100A. However, in recent CCTV cameras, since the camera body 100A is gradually downsized, the infrared cut filter is used. 110 and its drive mechanism (actuator 230) have become difficult to provide in the camera body 100A.

  Therefore, it has become promising to provide the infrared cut filter 110 together with the stop 230 in the lens barrel 200B as shown in FIG. In particular, as described in Patent Document 1, an infrared cut filter and a driving mechanism thereof are integrated into a diaphragm device.

  However, in the diaphragm device having a configuration in which the conventional infrared cut filter is integrated as described in Patent Document 1, a relatively thick filter is used as the infrared cut filter. When considering the operability of the infrared cut filter, it is necessary to adopt a configuration in which the infrared cut filter and the diaphragm blades are arranged on the front and back surfaces of the diaphragm substrate, respectively. Has occurred. When focus correction is taken into consideration, a dummy filter for aligning the optical path length must be used in addition to the infrared cut filter, which is also an obstacle to downsizing. In particular, when a dummy filter is used in addition to a thick infrared cut filter, the weight of the filter also increases, so the filter drive system also increases in size, meeting the demand for a smaller and lighter lens barrel. It was getting harder.

  In consideration of the above circumstances, the present invention can be reduced in size and weight while being integrally provided with an optical filter that can be inserted into and removed from the optical path, and can be easily attached to a lens barrel of a CCTV camera, for example. It is an object of the present invention to provide an aperture device that can perform the above-described operation.

  According to a first aspect of the present invention, there is provided a diaphragm device having a diaphragm substrate having an opening for forming an optical path, and being arranged on one plate surface of the diaphragm substrate and sliding along the plate surface to adjust the diaphragm of the optical path. An aperture blade, aperture driving means for driving the aperture blade to adjust the aperture of the optical path, an optical filter having a transmission characteristic corresponding to a wavelength, and the optical filter is inserted into or removed from the optical path A filter driving means, and the optical filter is formed in a thin film shape, and then integrally attached to a thin plate-like filter frame manufactured separately from the optical filter, thereby forming a thin plate-like optical filter unit as a whole. The optical filter unit is disposed on one plate surface side of the diaphragm substrate, and is provided slidable along the diaphragm blades. Characterized in that a driven part by serial filter drive means.

  According to a second aspect of the present invention, there is provided the diaphragm device according to the first aspect, wherein two diaphragm blades are provided in a stacked state, and are formed in the thin plate shape between the two diaphragm blades. The optical filter unit is arranged.

  A third aspect of the present invention is the diaphragm device according to the first or second aspect, wherein the optical filter is an infrared cut filter that blocks light in an infrared region, and is a thin film having a thickness of 0.25 mm or less. It is formed in the shape.

  A fourth aspect of the present invention is the diaphragm device according to any one of the first to third aspects, wherein the optical filter has a driven portion of the filter frame on a shaft provided at an end of the diaphragm substrate. The optical filter unit is supported so as to be rotatable, and the optical filter unit is rotated about its axis, whereby the optical filter unit is inserted into or removed from the optical path.

  The invention of claim 5 is the diaphragm device according to claim 4, wherein the filter frame for mounting the optical filter is formed in a substantially disc shape and has a frame body having a through hole in the center, And a driven portion extending from the frame main body, and a protruding portion for stabilizing the slide operation of the optical filter unit along the diaphragm blades is projected from the outer peripheral edge of the frame main body. In addition, when the optical filter is attached, a positioning edge is provided to match the outer peripheral edge of the optical filter using a jig from the outer periphery.

  A sixth aspect of the present invention is the diaphragm device according to any one of the first to fifth aspects, wherein the filter frame is formed of a material having flexibility in a thickness direction thereof.

  A seventh aspect of the present invention is the diaphragm apparatus according to any one of the first to sixth aspects, wherein the diaphragm driving unit and the filter driving unit are both disposed on the same side of the optical path on the diaphragm substrate. It is characterized by being.

  The invention according to an eighth aspect is the diaphragm device according to any one of the first to seventh aspects, wherein the filter driving means includes a second position where the optical filter unit deviates from the first position on the optical path. The optical filter unit is held by the magnetic force at the first position when it is on the first position side relative to the intermediate position, and the optical filter unit is located on the second position side relative to the intermediate position. It is characterized by comprising a filter holding means for holding at a second position by magnetic force.

  A ninth aspect of the present invention is the diaphragm device according to the eighth aspect, wherein the filter holding means includes a permanent magnet provided on a rotor of a motor that drives the optical filter unit, and the optical filter unit is the first filter. The permanent magnet is arranged at a position equidistant from the N and S poles adjacent to each other when operated to an intermediate position between the N position and the second position, and an attractive force is provided between the N and S poles. And a magnetic piece for generating a rotational biasing force to the rotor.

  A tenth aspect of the invention is the diaphragm device according to any one of the first to ninth aspects, wherein an ND filter different from the optical filter is provided in a through hole portion that forms a diaphragm opening of the diaphragm blade. The ND filter is characterized in that the transmittance in the infrared region has a spectral transmittance characteristic substantially equal to or less than the transmittance in the visible region.

  In the diaphragm device of the first aspect, the optical filter unit formed in a thin plate shape is disposed along with the diaphragm blades on one plate surface side of the diaphragm substrate, and is provided slidable along the diaphragm blades. Compared to the conventional example in which the diaphragm blades and the optical filters are arranged on both the front and back surfaces of the diaphragm substrate, the configuration can be simplified. In addition, since the entire optical filter unit has a thin plate shape, the optical filter unit can be arranged in a narrow space such as a gap between the diaphragm blades or a gap between the diaphragm blades and the diaphragm substrate. In addition, the optical filter unit can be easily incorporated into the aperture device while ensuring its own slide performance without hindering the operation of the aperture blades.

  Therefore, the aperture device can be made compact while the optical filter is integrated with the optical path so as to be freely inserted and removed. In addition, since the optical filter is formed in a thin film shape, the optical path length difference between when the optical filter is on the optical path and when it is not present can be almost eliminated, and a dummy filter for preventing defocusing is unnecessary. can do. As a result, it is possible to eliminate as much as possible the increase in weight and space required when assembling an optical filter, improving the ease of assembling when assembling into a lens barrel, etc., and reducing the size and weight of the lens barrel, etc. Can also contribute.

  According to the present invention, since the optical filter is attached to a filter frame manufactured separately, the optical filter and the filter frame can be made of different materials. In other words, optical filters can be manufactured by preferentially selecting materials with excellent optical characteristics, with little problem with processability and mechanical characteristics, and the filter frame has no problems with optical characteristics. Instead, it is possible to preferentially select a material having excellent mechanical characteristics and excellent workability from the viewpoint of forming the driven part. For example, an optical filter can be manufactured from thin glass that is easy to cut circularly but is difficult to perform complex processing (processing of driven parts, etc.), and a filter frame can be manufactured from thin plate-like plastic that can be easily processed. it can.

  In addition, since the filter frame having the driven part and the optical filter may be manufactured separately after being manufactured separately, it is only necessary to form a thin film to give specific optical characteristics only to the optical filter, which is wasteful. In addition, the conditions for forming the thin film need only be selected based on the material of the optical filter. For example, when the optical filter is made of glass, the temperature condition can be set higher than when the optical filter is made of plastic. Therefore, as a result, the processing can be facilitated and the characteristics can be improved, which can contribute to cost reduction. In addition, since it is not necessary to bear the mechanical strength necessary for driving the optical filter itself, the optical filter can be formed as thin as possible, which can contribute to the omission of the dummy filter described above.

  According to the second aspect of the present invention, since the optical filter unit is disposed in the gap between the two diaphragm blades, a special space for disposing the optical filter unit is not required, and the size reduction can be achieved. In addition, since the optical filter unit can be slid using the two diaphragm blades as a guide, the operation of the optical filter unit can be facilitated.

  According to the invention of claim 3, since the thickness of the optical filter is 0.25 mm or less, the optical path length difference due to the presence or absence of the optical filter can be almost eliminated, and the optical design in consideration of the focus shift. Can be made unnecessary. That is, a dummy filter is not necessary, and a reduction in size and weight including the drive system can be achieved. Further, since the optical filter is an infrared cut filter that transmits light in the visible light region and blocks light in the infrared (near infrared) region, it is suitable as an aperture device for a CCTV camera, and is used for photographing at night. In some cases, the optical filter can be removed from the optical path to allow infrared light to pass through, and during daytime shooting, the optical filter can be inserted into the optical path to capture infrared light. You can cut and shoot.

  The method of sliding the optical filter unit along the diaphragm blades may be a linear movement type or a rotary type. However, in the diaphragm device according to the fourth aspect of the present invention, the rotation about the shaft provided at the end of the diaphragm substrate is used. Since it is a dynamic type, the drive system of the optical filter unit can have a simple structure that saves space. In addition, the rotation type allows the optical filter unit to be driven without difficulty in a small gap between the aperture blades.

  According to the invention of claim 5, the outer peripheral edge of the frame body of the filter frame is provided with a positioning edge for matching the outer peripheral edge of the optical filter by using a jig from the outer periphery when attaching the optical filter. The optical filter can be attached to the filter frame while being easily positioned with a jig. In addition, it is advantageous to reduce the driving load of the optical filter unit to form the frame main body to the minimum size to which the optical filter can be attached, but in this case, the filter frame and the diaphragm blade are slightly warped. In such a case, the outer peripheral edge of the annular frame main body is likely to be caught on the edge of the through hole portion of the aperture blade during the sliding operation. In this regard, in the present invention, a protruding portion is provided on the outer peripheral edge of the frame main body to stabilize the sliding operation.

  In other words, the filter frame can be slid in a state in which the protruding portion is always placed on the diaphragm blade by providing the protruding portion at a necessary position while keeping the outer dimension of the frame main body small. As a result, catching can be prevented and the operation can be stabilized, so that it is possible to cope with some warping. In addition, when the frame body is made as small as possible, it becomes difficult to secure a bonding allowance when fixing the optical filter with an adhesive. Can be secured, and the ease of assembly is also improved.

  According to the invention of claim 6, since the filter frame has flexibility in its thickness direction, it can perform an impact absorbing function, and even when the thin film optical filter is made of glass, the impact Can be protected from.

  According to the seventh aspect of the present invention, the diaphragm driving means and the filter driving means, which are relatively large-volume parts, are provided on the same side with respect to the optical path, that is, they are larger in the thickness direction of the diaphragm substrate. Rather than arranging parts with dimensions (diaphragm drive means and filter drive means) on both sides of the optical path, they are placed together on one side of the diaphragm substrate, so the part on the opposite side is made thinner. Can do. Therefore, when assembling the aperture device into the lens barrel, the aperture device is inserted into the lens barrel from the side while the thinned portion is first inserted into the lens barrel without obstructing either driving means. And can be easily attached to a lens barrel or the like.

  According to the invention of claim 8, since the position of the optical filter is held at either the first position or the second position by magnetic force, when the insertion / removal operation of the optical filter is transmitted to the optical filter, The energization to the filter driving means can be stopped, and the power consumption of the filter driving means can be reduced.

  According to the ninth aspect of the present invention, since the magnetic force is obtained by using the permanent magnet of the rotor of the motor constituting the filter driving means, a wasteful configuration can be saved as much as possible at a low cost.

  According to the invention of claim 10, the ND filter can reduce the amount of infrared light transmitted during night photography when applied to, for example, a CCTV camera to the same extent as the light in the visible region. It is possible to prevent the light from being taken excessively. Therefore, a captured image that is easy to view can be obtained without causing the subject portion with strong infrared light to become too bright.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an exploded perspective view showing the overall configuration of the diaphragm device of the embodiment, FIG. 2 is an exploded perspective view showing the overall configuration of the diaphragm device in a state in which the optical filter is attached to the filter frame and unitized, and FIG. It is a block diagram of a unit.

  The diaphragm device 1 includes a rectangular plate-shaped diaphragm substrate 10 made of a resin molded product, and a pair of diaphragm blades 12 that are slidably assembled on the upper surface (on one plate surface) of the diaphragm substrate 10 so as to overlap each other. 13, a thin plate-like optical filter unit 15 disposed so as to be rotatable and slidable between the two diaphragm blades 12 and 13, and the diaphragm blades 12 and 13 and the optical filter unit 15 are assembled on the upper surface of the diaphragm substrate 10. In addition, a blade cover 14 that covers the diaphragm blades 12 and 13 on the diaphragm substrate 10, a diaphragm driving device (diaphragm driving means) 20 and a filter driving device (filter driving) assembled on the lower surface side of the diaphragm substrate 10. Means) 30.

  The aperture substrate 10 and the blade cover 14 are formed with openings 10a and 14a for forming an optical path (light path with the vertical central axis in the figure as an optical axis). Notched or hole-shaped through-hole portions 12e and 13e for forming openings are provided. Then, the diaphragm path can be adjusted by linearly sliding the diaphragm blades 12 and 13 on the diaphragm substrate 10 in the directions of the arrows f1 and f2. The aperture driving device 20 slides the aperture blades 12 and 13 via drive pins 21a and 21b provided on a drive lever (not shown), and is configured around a motor.

  The optical filter unit 15 is formed as a thin plate by forming an optical filter 152 having a transmission characteristic corresponding to a wavelength in a thin film shape, and then integrally mounting it on a thin filter frame 151 manufactured separately from the optical filter 152. It is configured as a unitary unit. Here, as the optical filter 152, an infrared cut filter that blocks light in the infrared region (including the near infrared region) is used. The filter drive device 30 is configured to insert and remove the optical filter unit 15 on the optical path by rotating and sliding the optical filter unit 15 via the drive lever 31, and is configured around a motor. Yes.

  More specifically, in the optical filter unit 15, the optical filter 152 formed in a thin film shape having a thickness of 0.25 mm or less is superimposed on a thin plate-shaped filter frame 151 having a thickness of 0.12 mm or less and attached integrally by adhesion or the like. As a whole, the thickness is as thin as about 0.3 mm. In this case, the optical filter 152 is formed of glass, the filter frame 151 is formed of a plastic thin plate, and the filter frame 151 is flexible in the thickness direction. Therefore, the filter frame 151 can perform an impact absorbing function, and the thin-film optical filter 152 can be protected from the impact. The optical filter unit 15 is inserted in a slight gap between the two diaphragm blades 12 and 13 and is provided so as to be slidable along the diaphragm blades 12 and 13. By being sandwiched between the two diaphragm blades 12 and 13 in this way, the optical filter unit 15 can smoothly slide with the surface of the diaphragm blades 12 and 13 as a guide surface, and is stable while being thin. Can be inserted and removed.

  Further, ND filters 12f and 13f different from the optical filter 15 made of an infrared cut filter are attached to the through holes 12e and 13e forming the aperture openings of the aperture blades 12 and 13, respectively. These ND filters 12f and 13f are formed so that the transmittance of light in the infrared region has a spectral transmittance characteristic that is approximately equal to or less than or equal to the transmittance of light in the visible region.

  A plurality of four guide pins 11 a, 11 b, 11 c, and 11 d with tip hooks that engage with the diaphragm blades 12 and 13 are provided in the vicinity of the peripheral edge of the upper surface of the diaphragm substrate 10. In addition, long grooves 12a, 12b, 12c, 13a, 13b, and 13c are provided in the vicinity of the side edges of the diaphragm blades 12 and 13 in parallel with the side edges. Then, by fitting these long grooves 12a, 12b, 12c, 13a, 13b, and 13c to the guide pins 11a, 11b, 11c, and 11d, the diaphragm blades 12 and 13 are linearly slid on the top surface of the diaphragm substrate 10 in the directions of arrows f1 and f2. It is held freely. Note that the tip hook portions of the guide pins 11a, 11b, 11c, and 11d prevent the diaphragm blades 12 and 13 from coming off upward. In FIG. 1, what is indicated by reference numeral 16 provided on the diaphragm substrate 10 is a mounting bracket for mounting and fixing the diaphragm device 1 to a lens barrel or the like (described later with reference to FIG. 7).

  As elements for driving the diaphragm blades 12 and 13, first, lateral grooves 12 d and 13 d orthogonal to the sliding direction of the diaphragm blades 12 and 13 are provided at the longitudinal ends of the diaphragm blades 12 and 13, respectively. Yes. On the other hand, the diaphragm drive device 20 attached to the lower surface side of the diaphragm substrate 10 is provided with a drive lever (not shown). This drive lever has drive pins 21 a and 21 b protruding from the upper surface side of the diaphragm substrate 10 at both ends, and the central part thereof is coupled to a motor shaft (not shown) of the diaphragm drive device 20. The drive pins 21a and 21b are respectively engaged with the lateral grooves 12d and 13d provided at the longitudinal ends of the diaphragm blades 12 and 13, respectively. By rotating the pins 21a and 21b, the two diaphragm blades 12 and 13 are linearly slid to adjust the aperture of the optical path.

  In the optical filter unit 15 arranged between the two diaphragm blades 12 and 13 that slide linearly in this way, as shown in FIGS. 1 and 3, the optical filter 152 capable of blocking the optical path is provided with the diaphragm blade 12. , 13 are formed in a slightly larger circle than the through-hole portions 12e, 13e. As shown in detail in FIG. 3A, the filter frame 151 includes a frame main body 151a that is formed in a substantially disc shape and has a through hole 151h in the center, and a crank lever portion that extends in an L shape from the frame main body 151a. Driven portion) 151b. The through hole 151 h of the frame body 151 is formed as a circular hole that is slightly larger than the through holes 12 e and 13 e of the aperture blades 12 and 13. Then, as shown in FIG. 3B, a circular optical filter 152 is overlaid on the upper surface of the frame body 151 so as to cover the through hole 151h, and in this state, as shown in FIG. 3C. These are fixed with an adhesive 153. In this case, the amount of protrusion of the adhesive 153 is regulated so that it falls within the range of the step between the optical filter 152 and the filter frame 151.

  Protruding portions 151f and 151g for stabilizing the sliding operation of the optical filter unit 15 along the diaphragm blades 12 and 13 project from the outer peripheral edge of the frame main body 151a of the filter frame 151, and the optical filter 152 is provided. A positioning edge 151k is provided from the outer periphery to match the outer peripheral edge of the optical filter 152 using a jig (not shown: vertical pin, for example). The positioning edge 151k is provided at at least three places spaced in the circumferential direction.

  Thus, since the positioning edge 151k is provided, the optical filter 152 can be attached to the filter frame 151 while easily positioning with a jig. In addition, it can be said that it is advantageous to reduce the driving load of the optical filter unit 15 to form the frame main body 151a to a minimum size to which the optical filter 152 can be attached. When the diaphragm blades 12 and 13 are slightly warped, the outer peripheral edge of the annular frame main body 151a is likely to be caught on the edge of the through-hole portion 12e of the diaphragm blade 12 during the sliding operation. In this respect, in the filter frame 151 of the present embodiment, the protruding portions 151f and 151g are provided on the outer peripheral edge of the frame main body 151a to stabilize the sliding operation.

  That is, the filter frame can be slid in a state in which the protruding portions 151f and 151g are always placed on the diaphragm blades 12 by providing the protruding portions 151f and 151g at necessary locations while keeping the outer dimensions of the frame main body 151a small. I am doing so. As a result, catching can be prevented and the operation can be stabilized, so that it is possible to cope with some warping.

This point will be briefly described with reference to the drawings. FIG. 4 shows a comparative example in which the filter frame 151 has the protruding portions 151f and 151g, and FIG. 5 shows a comparative example without the protruding portion.
The aperture blade 12 on which the optical filter unit 15 slides is provided with a through-hole portion 12e. The through-hole portion 12e is provided with a V-shaped cut portion 12ev for mounting the ND filter 12f. Yes. Here, if the outer shape of the frame main body 151a of the filter frame 151 is circular as in the comparative example of FIG. 5 and does not have a protruding portion, the diaphragm blade 12 and the filter frame 151 are slightly warped. In this case, when inserting / removing the filter frame 151 (optical filter unit 15) with respect to the optical path, particularly when inserting the filter frame 151 into the optical path, the outer edge of the filter frame 151 is a V-shaped cut portion of the through-hole portion 12e of the aperture blade 12. There is a risk of being caught at 12ev.

  On the other hand, as in the present embodiment shown in FIG. 4, when the protruding portions 151 f and 151 g are provided on the outer peripheral edge of the frame main body 151 of the filter frame 151, the portion where the filter frame 151 rides on the diaphragm blade 12 ( Therefore, even if there is some warping, the filter frame 151 can be prevented from being caught by the diaphragm blade 12 side. Can do. That is, since the protruding portions 151f and 151g are provided, even if the diaphragm blades 12 and the filter frame 151 are slightly warped, the sliding operation of the optical filter unit 15 can be ensured smoothly without being caught. Similar effects can be obtained for the diaphragm blade 13 side.

  Further, when the frame main body 151a is made as small as possible, it becomes difficult to secure a bonding allowance when fixing the optical filter 152 with the adhesive 153. However, since there are the protruding portions 151f and 151g, Since the space for the protruding adhesive 153 to be secured can be secured, the assembling property is also improved.

Next, a structure for sliding the optical filter unit 15 will be described.
As shown in FIG. 3A, the filter frame 151 has an L-shaped crank lever portion (driven portion) 151b extending outward at one end thereof. A through hole 151c is provided in the bent portion of the crank lever portion 151b, and a long hole 151d is provided in the distal end side of the crank lever portion 151b. A long hole 151e is also provided in front of the through hole 151c.

  A bracket 10b for mounting the filter driving device 30 is integrally projected on one side edge of the diaphragm substrate 10, and a motor (main element of the filter driving device 30) is provided on the lower surface side of the bracket 10b. Are not attached). A support shaft 10c for supporting the optical filter unit 15 is provided in the vicinity of the bracket 10a, and a drive pin 31a provided at the tip of the drive lever 31 of the filter drive device 30 is provided in the vicinity of the support shaft 10c. It protrudes.

  The optical filter unit 15 can be rotated along the surfaces of the diaphragm blades 12 and 13 around the support shaft 10c by fitting a through hole 151c provided in a bent portion of the crank lever portion 151b to the support shaft 10c. It is supported. Further, the drive pin 31a of the filter driving device 30 is engaged with a long hole 151d provided on the distal end side of the crank lever portion 151b, so that the drive of the drive pin 31a is driven by driving the filter driving device 30. By the movement, the optical filter unit 15 rotates about the support shaft 10c, whereby the optical filter 152 is inserted into or removed from the optical path (the optical filter 152 is inserted into and removed from the optical path). It has become so.

  In this case, both the aperture driving device 20 and the filter driving device 30 are disposed on the same side of the optical path on the aperture substrate 10. That is, the diaphragm driving device 20 and the filter driving device 30 are arranged together on one end side in the longitudinal direction of the diaphragm substrate 10. Therefore, the other end side where the drive devices 20 and 30 are not provided is kept as a thin plate-like body.

Next, the configuration of the filter driving device 30 that rotates the optical filter unit 15 to drive the optical filter 152 with respect to the optical path will be described in detail.
Even when the energization of the motor is stopped, the filter driving device 30 moves the optical filter unit 15 to the first position (filter use position) on the optical path or the second position (filter non-use position) off the optical path. ) Is provided with a filter holding function (filter holding means) for positioning and holding.

  The filter holding function means that the optical filter unit 15 is at a first position than an intermediate position between a first position (filter use position) on the optical path and a second position (filter non-use position) deviated from the optical path. When the optical filter unit 15 is on the side, the optical filter unit 15 is urged toward the first position side by the magnetic force, so that the optical filter unit 15 is held at the first position. When the optical filter unit 15 is on the side, the optical filter unit 15 is urged to the second position side by a magnetic force, thereby holding the optical filter unit 15 at the second position.

  In this embodiment, the function of holding the optical filter unit 15 at either the first position or the second position (filter holding function = filter holding means) is applied to the rotor of the motor that drives the optical filter unit 15. This is achieved (configured) by a permanent magnet provided and a magnetic piece that generates an attractive force between the N pole or S pole of the permanent magnet and thereby gives a rotational biasing force to the rotor.

This will be described in detail with reference to FIG.
As shown in FIG. 6A, the motor constituting the main body of the filter drive device 30 includes a rotor 32 having a rotor shaft 33, a coil bobbin 35 disposed around the rotor 32 for rotationally driving the rotor 32, A coil 36 wound around the coil bobbin 35, a cylindrical yoke (not shown) externally fitted to the coil bobbin 35, and the like. Here, the yoke, the coil bobbin 35 and the coil 36 constitute a stator.

  The rotor 32 is composed of a cylindrical permanent magnet whose both ends in the diameter direction are polarized to N and S poles. The rotor shaft 33 is made of resin, and a proximal end portion of the drive lever 31 that engages with the optical filter unit 15 is coupled to a distal end portion that protrudes to the outside. A soft magnetic piece 37 is disposed between the inside of the yoke (not shown) of the stator and the rotor 32. As shown in FIG. 6 (a), the soft magnetic piece 37 is formed on the rotor 32 when the drive lever 31 is operated so that the optical filter unit 15 is at an intermediate position between the first position and the second position. It is disposed at a position that is substantially equidistant from the N pole and the S pole, and generates a suction force between the N pole and the S pole of the rotor 32, thereby providing a function of applying a rotational biasing force to the rotor 32. Yes.

  FIG. 6B shows the rotational position of the rotor 32 when the optical filter unit 15 reaches the second position (position off the optical path) as a result of the rotor 32 swinging in the direction of arrow (A). Yes. At this time, since the N pole of the rotor 32 approaches the soft magnetic body 37, a large magnetic attraction force is generated between the N pole and the soft magnetic body 37, and the energization of the motor is stopped by the magnetic attraction force. Even so, the rotor 32, that is, the optical filter unit 15 is held in the second position.

  FIG. 6C shows the rotational position of the rotor 32 when the optical filter unit 15 reaches the first position (position on the optical path) as a result of the rotor 32 swinging in the arrow (b) direction. At this time, since the south pole of the rotor 32 approaches the soft magnetic body 37, a large magnetic attraction force is generated between the south pole and the soft magnetic body 37, and the energization of the motor is stopped by the magnetic attraction force. Even so, the rotor 32, that is, the optical filter unit 15 is held in the first position.

  Accordingly, the optical filter unit 15 can be held in either the first position or the second position by the magnetic force of the permanent magnet in this way, and the motor power is not necessary in this state. Can be eliminated, and the life of the battery power source can be extended. In particular, in the diaphragm device 1 of the present embodiment, the magnetic force (that is, the urging force) used for positioning the optical filter unit 15 is obtained using the permanent magnet of the rotor, so that the soft magnetic piece 37 is only arranged at a predetermined position. It can be set as the simple structure.

Next, the operation will be described assuming that the aperture device 1 is applied to a CCTV camera day and night monitoring.
In this diaphragm device 1, by drivingly controlling the diaphragm driving device 20, the drive pins 21 a and 21 b that engage with the diaphragm blades 12 and 13 are rotated, and the diaphragm blades 12 and 13 are linearly slid by the rotation. Thus, the aperture of the optical path can be adjusted. Since the ND filters 12f and 13f attached to the through-hole portions 12e and 13e of the aperture blades 12 and 13 are positioned on the optical path at a position close to the maximum aperture, the action of the ND filter appears in the photographing light.

  On the other hand, in the diaphragm device 1, the drive lever 31 is rotated by driving the filter driving device 30, so that the optical filter unit 15 is rotated and slid about the support shaft 10 c by the rotation, and the optical drive unit 31 is rotated. The optical filter 152 can be inserted and removed with respect to the road.

  Since the optical filter 152 in this case is an infrared cut filter, the infrared region of the photographing light can be cut by positioning the optical filter 152 on the optical path. In addition, the ND filters 12f and 13f can reduce the amount of infrared light transmitted during night photographing to the same extent as that in the visible region, thereby preventing excessive infrared light from being photographed. As a result, the subject portion with strong infrared light does not become too bright, and an easy-to-view captured image can be obtained.

  In the present diaphragm device 1 capable of obtaining such an action, the optical filter unit 152 is formed in a thin plate shape, and is arranged together with the diaphragm blades 12 and 13 on one plate surface (upper surface) side of the diaphragm substrate 10. Since it is slidable along the diaphragm blades 12 and 13, the configuration of the diaphragm device 1 can be simplified.

  In particular, since the optical filter unit 15 is arranged in a slight gap between the two diaphragm blades 12 and 13, no extra space for the optical filter unit 15 is required, and the thickness direction of the diaphragm device 1 Can be made compact. Further, since the optical filter unit 15 can be slid using the two diaphragm blades 12 and 13 as a guide, the operation of the optical filter unit 15 can be smoothed.

  Further, since the optical filter 152 is formed in a thin film having a thickness of 0.25 mm or less, the optical path length difference due to the presence or absence of the optical filter 152 can be almost eliminated, and the optical design in consideration of the focus shift is not required. be able to. That is, a dummy filter is not necessary, and a reduction in size and weight including the drive system can be achieved.

  Accordingly, while the optical filter 152 is integrated in a removable manner with respect to the optical path, the entire diaphragm device 1 can be made compact (particularly thin), and can be easily incorporated into a lens barrel or the like. It can contribute to light weight and downsizing of cylinders.

  Further, since the slide method of the optical filter unit 15 is not a linear slide type like the diaphragm blades 12 and 13 but a rotary type, the drive system of the optical filter unit 15 has a simple structure of a space-saving type. Therefore, it is possible to design without difficulty in the engagement with the drive system of the diaphragm blades 12 and 13.

  In particular, in the present diaphragm device 1, the diaphragm driving device 20 and the filter driving device 30 are provided on the same side with respect to the optical path. Therefore, when the diaphragm device 1 is assembled to a lens barrel of a CCTV camera, for example, Thus, the diaphragm device 1 can be easily assembled to the lens barrel without disturbing the assembly of the drive devices 20 and 30.

FIG. 7 shows an example of attachment of the diaphragm device 1 to the lens barrel 2.
There is a side hole 2a in the peripheral wall of the lens barrel 2, and the diaphragm device 1 can be inserted into the side hole 2a from a direction perpendicular to the optical axis direction. A mounting seat 2b is provided at one end of the side hole 2a, and a screw hole 2c is provided on the front surface of the mounting seat 2b. On the other hand, the diaphragm substrate 10 of the diaphragm device 1 is provided with a mounting bracket 16 for use in fixing. The mounting bracket 16 has a notch 16a for threading and a mounting seat 2b on the lens barrel 2 side. A contact surface 16b is provided.

  In this diaphragm device 1, both the diaphragm driving device 20 and the filter driving device 30 are arranged together on one side with respect to the optical path, so the side opposite to the side where the driving devices 20, 30 are located is a thin plate-like shape. Is kept. Accordingly, when the diaphragm device 1 is assembled to the lens barrel 2, the thin side of the diaphragm device 1 is inserted into the side hole 2a of the lens barrel 2, and the contact surface 16b of the mounting bracket 16 is attached to the lens barrel 2 side. The diaphragm device 1 can be attached to the lens barrel 2 by contacting the front surface of the seat 2a and tightening the screw 17 into the screw hole 2b of the mounting seat 2a through the notch 16a of the mounting bracket 16 in this state. Therefore, the lens barrel 2 can be easily assembled and the workability is good.

  Moreover, in this diaphragm | throttle device, since the optical filter 152 is attached to the filter frame 151 manufactured separately, the optical filter 152 and the filter frame 151 can be comprised with another material. That is, the optical filter 152 can be manufactured by preferentially selecting a material excellent in optical characteristics without causing much problem in processability and mechanical characteristics, and the filter frame 151 can be manufactured in terms of optical characteristics. In view of forming the crank lever portion 151b, which is a driven portion, it is possible to preferentially select a material having excellent mechanical characteristics and excellent workability without any problem.

  For example, as in this embodiment, the optical filter 152 is manufactured from thin glass that is easy to cut circularly but is difficult to perform complex processing (processing of the driven part), and the filter frame 151 is a thin plate that is easy to process. It can be made of plastic.

  Further, since the filter frame 151 having the crank lever portion 151b and the optical filter 152 are manufactured separately and then attached together, a thin film formation (for example, vapor deposition) for giving specific optical characteristics is performed. In addition, there is no waste, and the conditions for forming the thin film need only be selected based on the material of the optical filter 152 only. For example, when the optical filter 152 is made of glass, the temperature condition can be set higher than when the optical filter 152 is made of plastic.

  Therefore, as a result, the processing can be facilitated and the characteristics can be improved, which can contribute to cost reduction. In addition, since it is not necessary to bear the mechanical strength necessary for driving the optical filter itself, the optical filter 152 can be formed as thin as possible, which also contributes to the omission of the dummy filter described above.

  In the above-described embodiment, the blade cover 14 is attached to the upper surface of the diaphragm substrate 10 for the purpose of preventing the diaphragm blades 12 and 13 and the like from falling off. However, the diaphragm blades 12 and 13 are guide pins 11a on the diaphragm substrate 10 side. The blade cover 14 does not necessarily have to be attached because it is prevented from falling off by ˜11d.

  In the above embodiment, the case where the diaphragm is adjusted by the two diaphragm blades 12 and 13 has been described. However, the present invention can also be applied to the case where the diaphragm is adjusted by one diaphragm blade. In that case, for example, the optical filter unit 15 may be disposed in the gap between one diaphragm blade and the diaphragm substrate.

  In the above embodiment, the optical filter 152 is made of glass. However, the optical filter 152 may be made of plastic. In this case as well, the optical filter 152 can be made of a material different from that of the filter frame 151, so that the above-described advantages can be utilized.

It is a disassembled perspective view which shows the whole structure of the aperture_diaphragm | restriction apparatus of embodiment of this invention. It is a disassembled perspective view which shows the whole structure of the aperture_diaphragm | restriction apparatus in the state which attached the optical filter to the filter frame and unitized. It is a block diagram of an optical filter unit, (a) is an enlarged plan view, (b) is a IIIb-IIIb arrow sectional view of (a), (c) is an IIIc part enlarged view of (b). It is a principal part top view which shows the case of embodiment of this invention which has a protruding part in a filter frame. It is a principal part top view which shows the comparative example which does not have a protrusion part in a filter frame. It is a figure which shows the structure of a filter drive device, (a) shows a state when an optical filter exists in the intermediate position of the 1st position (position on an optical path) and the 2nd position (position on the optical path). FIG. 5B is a diagram showing a state when the optical filter is in the second position (position off the optical path), and FIG. 5C is a diagram when the optical filter is in the first position (position on the optical path). It is a figure which shows the state of. It is a perspective view used for explanation at the time of attaching a diaphragm device of an embodiment to a lens barrel from the side. It is a schematic block diagram which shows the relationship between the aperture_diaphragm | restriction in a conventional CCTV camera system, and an optical filter, (a) is a figure which shows the state which located the optical filter on the optical path, (b) is the state which removed the optical filter from the optical path FIG. It is a schematic block diagram which shows the relationship between the aperture_diaphragm | restriction in another conventional CCTV camera system, and an optical filter, (a) is a figure which shows the state which has located the optical filter on the optical path, (b) is the optical filter removed from on the optical path FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Diaphragm apparatus 2 Lens barrel 10 Aperture board | substrate 10a Opening part 12, 13 Diaphragm blade 12e, 13e Through-hole part 12f, 13f ND filter 15 Optical filter unit 151 Filter frame 151a Frame main body 151b Crank lever part (driven part)
151f, 151g Protruding portion 151h Through hole
151k Positioning edge 152 Optical filter 20 Aperture driving device (aperture driving means)
30 Filter driving device (filter driving means)
32 Rotor (permanent magnet)
36 Coil (stator)
37 Soft magnetic material

Claims (10)

  A diaphragm substrate having an opening for forming an optical path, a diaphragm blade disposed on one plate surface of the diaphragm substrate and adjusting the optical path by sliding along the plate surface, and adjusting the aperture of the optical path In order to achieve this, there are provided diaphragm driving means for driving the diaphragm blades, an optical filter having a transmission characteristic corresponding to a wavelength, and filter driving means for inserting or removing the optical filter on the optical path, The optical filter is formed into a thin film and then integrally attached to a thin plate-like filter frame manufactured separately from the optical filter, so that the whole is configured as a thin plate-like optical filter unit. It is arranged on one plate surface side of the diaphragm substrate and is provided so as to be slidable along the diaphragm blades, and is also mounted on the filter frame by the filter driving means. Throttle apparatus characterized in that a moving portion. The aperture device according to claim 1,
Two diaphragm blades are provided in a state where the diaphragm blades are laminated with each other, and the optical filter unit formed in the thin plate shape is disposed between the two diaphragm blades. The aperture device according to claim 1 or 2,
A diaphragm device, wherein the optical filter is an infrared cut filter that blocks light in an infrared region, and is formed into a thin film having a thickness of 0.25 mm or less. The diaphragm device according to any one of claims 1 to 3,
In the optical filter, the driven portion of the filter frame is rotatably supported on a shaft provided at an end portion of the diaphragm substrate, and the optical filter unit is rotated around the shaft. An aperture device characterized by being inserted into or removed from the optical path. The diaphragm device according to claim 4,
A filter frame for mounting the optical filter includes a frame main body that is formed in a substantially disc shape and has a through hole in a central portion thereof, and the driven portion that extends from the frame main body. A protruding portion for stabilizing the slide operation of the optical filter unit along the diaphragm blades protrudes from the outer peripheral edge, and a jig is used from the outer periphery to attach the optical filter when attaching the optical filter. A squeezing device characterized in that a positioning edge for matching with the outer peripheral edge is provided. The diaphragm device according to any one of claims 1 to 5,
A diaphragm device, wherein the filter frame is formed of a material having flexibility in a thickness direction thereof. The diaphragm device according to any one of claims 1 to 6,
The diaphragm device characterized in that both the diaphragm driving means and the filter driving means are arranged on the same side of the optical path on the diaphragm substrate. The diaphragm device according to any one of claims 1 to 7,
The filter driving means moves the optical filter unit to the first position when the optical filter unit is on the first position side with respect to the intermediate position between the first position on the optical path and the second position off the optical path. And a filter holding means for holding the optical filter unit at the second position by magnetic force when the optical filter unit is at the second position side of the intermediate position. . The diaphragm device according to claim 8, wherein
A permanent magnet provided on a rotor of a motor that drives the optical filter unit; and when the optical filter unit is operated to an intermediate position between the first position and the second position. The magnetic piece is arranged at a position equidistant from the N and S poles adjacent to each other and generates an attractive force between the N and S poles, thereby giving a rotational biasing force to the rotor. A diaphragm device characterized by. The diaphragm device according to any one of claims 1 to 9,
An ND filter that is different from the optical filter is provided in the through hole portion that forms the aperture opening of the aperture blade, and the ND filter has a transmittance in the infrared region that is substantially the same as that in the visible region. An aperture device having spectral transmittance characteristics equal to or lower than those of the same.

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