JP2006139223A - Optical filter of diaphragm device, and diaphragm device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical filter satisfying the conditions optimum for being equipped so as to be freely extractable and insertable from/to the surface of a light path in a diaphragm device that: (a) thickness is reduced and cracks are not caused; (b) weight is light and handleability is satisfactory; (c) workability is satisfactory and assembling is possible in a direct movable manner without being fitted to a movable frame causing increase in weight or increase in volume; (d) warpage and peeling of films are hardly caused owing to an ensured slide operation, and the like, and to provide a diaphragm device using the optical filter. <P>SOLUTION: The infrared cut filter for a diaphragm device is equipped so as to be freely slidable along the sheet face of a diaphragm substrate 10 having an opening part 10a forming the light path, and is slid by a filter driving means 30, is thus inserted into the surface of the light path or removed from the surface of the light path. The filter is obtained by using a plastic thin film (a thin film of a norbornene based resin) having a heat resisting temperature at which film deposition by vapor deposition or sputtering is possible as a filter base material, and forming multilayer films with almost the same thickness on the surface and back face thereof by vapor deposition or sputtering. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical filter for an aperture device that is assembled in a photographing device such as a CCTV (monitoring camera system) lens, and an aperture device equipped with the optical filter.

  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 imaging 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 shooting, the filter is removed from the front of the image sensor, and monochrome shooting is performed based on light in the infrared wavelength range and visible wavelength range.

  FIGS. 7A and 7B 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 4A shows a state where the infrared cut filter 110 is inserted on the optical path L, and FIG. 4B 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. 7A, since the infrared cut filter 110 is inserted on the optical path L, the light incident on the lens barrel 200A enters the camera main 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 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. 8A and 8B 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 the conventional example of FIG. It is provided not inside but in the lens barrel 200B. 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.

  By the way, when an infrared cut filter is movably mounted in the above-described photographing apparatus or the like (that is, can be inserted into and removed from the optical path), glass or quartz is often used because the infrared cut filter itself is expected to have a corresponding rigidity. In general, an optical filter (see, for example, Patent Document 2 and Patent Document 3) having a film formed on the surface thereof is used as a filter substrate.

JP 2002-189238 A JP 2003-29027 A JP 2000-314808 A

  However, in the case of an optical filter using glass or quartz as a filter base material, since it is hard and easily broken, complicated shape processing is difficult. For this reason, in the case of being equipped with a movable type, it is difficult to configure it so that only the filter is moved directly, and the filter must be fitted to the movable frame for use, and the movable part tends to be large. In addition, when it is movable, it should be thin and light, but it tends to be thick and heavy.

  Particularly in recent CCTV cameras, with the downsizing of the camera body 100A, an infrared cut filter and its driving mechanism have been integrated into a diaphragm device in a lens barrel. If an infrared cut filter using quartz or quartz as a filter base is used, there is a limit to the compactness and operation performance of the apparatus.

In consideration of the above circumstances, the present invention is the optimum condition for detachably installing on the optical path of the aperture device, that is,
(A) Small in thickness and does not crack (b) Lightweight and easy to handle (c) Good workability and can be directly assembled without being fitted into a movable frame that leads to increased weight and volume (d) An optical filter that can satisfy the conditions such that warpage and film peeling are unlikely to occur, and a diaphragm device that can be reduced in size and weight by using the optical filter. The purpose is to provide.

  The invention according to claim 1 is slidably mounted along the plate surface of the diaphragm substrate having an opening that forms an optical path, and is slid by the filter driving means to be inserted into the optical path or from the optical path. In the optical filter for the diaphragm device to be removed, a plastic thin plate with a heat-resistant temperature that can be deposited by vapor deposition or sputtering is used as a filter substrate, and multilayer films with approximately the same thickness are formed on both front and back surfaces by vapor deposition or sputtering. It is characterized by becoming.

  A second aspect of the invention is an optical filter for a diaphragm device according to the first aspect, wherein a thin plate of norbornene resin is used as the plastic thin plate.

  Invention of Claim 3 is an optical filter for diaphragm | throttle devices of Claim 1 or 2, Comprising: It is an infrared cut filter which interrupts | blocks the light of the infrared region whose thickness is 0.25 mm or less. And

  Invention of Claim 4 is an optical filter for diaphragm | throttle devices in any one of Claims 1-3, Comprising: The substantially circular filter main-body part of the magnitude | size which covers the optical path of the said aperture_diaphragm | restriction board | substrate, This filter main-body part A crank-shaped lever portion that extends further, a shaft hole is provided in the bent portion of the crank-shaped lever portion for rotatably supporting the filter, and the filter drive is provided at the distal end side of the lever portion. An engaging hole for engaging a driving pin of the means is provided, and the entire shape is processed by press-cutting a filter material in which a multilayer film is formed on the plastic thin plate.

  According to a fifth aspect of the present invention, there is provided a diaphragm device comprising: a diaphragm substrate having an opening that forms an optical path; and a diaphragm substrate that is disposed on one plate surface of the diaphragm substrate and slides 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 The optical filter according to any one of claims 1 to 4 is used as the optical filter, and the optical filter is disposed on one plate surface side of the diaphragm substrate, It is characterized by being slidable along the diaphragm blades.

  A sixth aspect of the present invention is the diaphragm device according to the fifth aspect, wherein two diaphragm blades are provided in a stacked state, and the optical filter is disposed between the two diaphragm blades. It is characterized by that.

  The invention of claim 7 is the diaphragm device according to claim 5 or 6, wherein the optical filter is rotatably supported by a shaft provided at an end portion of the diaphragm substrate, and the shaft is centered on the shaft. It is inserted into the optical path or removed from the optical path by being rotated.

  The invention of claim 8 is the diaphragm device according to any one of claims 5 to 7, wherein both the diaphragm driving means and the filter driving means are arranged on the same side of the optical path on the diaphragm substrate. It is characterized by being.

  A ninth aspect of the present invention is the diaphragm device according to any one of the fifth to eighth aspects, wherein the filter driving means includes a first position on the optical path and a second position where the optical filter deviates from the optical path. The optical filter is held by the magnetic force at the first position when it is on the first position side from the intermediate position with respect to the position, and the optical filter is moved to the second position when the optical filter is on the second position side from the intermediate position. A filter holding means for holding the position by magnetic force is provided.

  A tenth aspect of the present invention is the diaphragm device according to the ninth aspect, wherein the filter holding means includes a permanent magnet provided on a rotor of a motor that drives the optical filter, and the optical filter is moved to the first position. When the magnet is operated to an intermediate position between the second pole and the second pole, the permanent magnet is disposed at an equal distance from the N pole and S pole adjacent to each other, and generates an attractive force between the N pole and the S pole. And a magnetic piece for applying a rotational biasing force to the rotor.

  The invention of claim 11 is the diaphragm apparatus according to any one of claims 5 to 10, 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 the transmittance in the visible region.

  The optical filter for a diaphragm device according to the first aspect of the present invention uses a heat-resistant plastic thin plate instead of glass or quartz as a filter base material, and forms multilayer films having substantially the same thickness on both front and back surfaces by vapor deposition or sputtering. Therefore, it is lightweight, and even if the thickness is reduced, it is hard to break and has good handleability. In addition, since the shape can be freely processed by a mass-productive method such as press cutting, it can be easily assembled directly into a movable type without being fitted to a movable frame that leads to an increase in weight or volume. In addition, since a multilayer film having the same thickness is formed on both sides, warping and peeling of the film hardly occur. Accordingly, when the slide device is slidably incorporated in the aperture device, a stable and reliable slide operation can be ensured, and an increase in volume and weight can be suppressed, and the overall aperture device can be made compact.

  According to the invention of claim 2, since a norbornene-based resin thin plate is used as the plastic thin plate, the heat resistance during film formation can be sufficiently exerted, and as an optical filter equipped movably High optical characteristics and dimensional stability can be exhibited.

  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 achieved. It can be made unnecessary. That is, it is not necessary to use a dummy filter for adjusting the optical path length, and the size and weight can be reduced including the drive system. Moreover, since it is an infrared cut filter, it is suitable for application to an aperture device for a CCTV camera that is also used day and night.

  According to the invention of claim 4, since the entire shape is processed by press-cutting a filter material in which a multilayer film is formed on a plastic thin plate, a movable frame is used for the diaphragm device only by using mass production equipment. It is possible to satisfy the necessary shape when directly mounting in a sliding slide type.

  According to the diaphragm device of the fifth aspect of the present invention, an optical filter having a plastic thin plate as a filter base is disposed along with the diaphragm blades on one plate surface side of the diaphragm substrate, and is slidable along the diaphragm blades. Therefore, the configuration of the diaphragm device can be simplified while reducing the weight. In addition, the optical filter manufactured in a thin plate shape can be placed in a narrow space such as the gap between the diaphragm blades or the gap between the diaphragm blades and the diaphragm substrate without hindering the operation of the diaphragm blades or its own operation. The aperture device can be made compact (particularly thin) while the optical filter is integrally incorporated in the optical path so as to be freely inserted and removed. In addition, since the optical filter is made thinner, it is not necessary to provide a dummy filter for preventing out-of-focus, and as a result, an increase in weight and space can be eliminated. The improvement of the property can be achieved, and it can greatly contribute to the light weight and downsizing of the lens barrel and the like.

  According to the invention of claim 6, since the optical filter is disposed in the gap between the two diaphragm blades, a special space for disposing the optical filter is not required, and the size can be reduced. In addition, since the optical filter can be slid using the two diaphragm blades as a guide, the operation of the optical filter can be facilitated.

  According to the seventh aspect of the present invention, since the slide system of the optical filter is turned, the drive system of the optical filter can have a simple structure with a small space. In addition, the rotation type allows the optical filter to be driven without difficulty in a small gap between the aperture blades.

  According to the invention of claim 8, since the diaphragm driving means and the filter driving means are provided on the same side with respect to the optical path, when the diaphragm device is assembled to the lens barrel, one of the driving means becomes an obstacle. Therefore, the diaphragm device can be easily assembled to the lens barrel, and can be easily attached to the lens barrel and the like.

  According to the ninth aspect of the present invention, since the position of the optical filter is held at either the first position or the second position by the magnetic force, the power consumption of the filter driving means can be reduced.

  According to the invention of claim 10, since the magnetic force is obtained by using the permanent magnet of the rotor of the motor constituting the filter driving means, it is possible to reduce the wasteful configuration as much as possible and to reduce the cost.

  According to the invention of claim 11, the ND filter can reduce the amount of infrared light transmitted at night photographing when applied to a CCTV camera, for example, 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, an optical filter according to an embodiment of the present invention and a diaphragm device incorporating the same will be described with reference to the drawings.
FIG. 1 is an exploded perspective view showing a configuration of a diaphragm device 1 according to the embodiment.
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-film optical filter 15 that is rotatably arranged between these two diaphragm blades 12, 13, and the diaphragm blades 12, 13 and the optical filter 15 are assembled on the upper surface of the diaphragm substrate 10. The diaphragm cover 14 is placed on the diaphragm substrate 10 so as to cover the diaphragm blades 12 and 13, and the diaphragm driving device 20 and the filter driving device 30 are assembled on the lower surface side of the diaphragm substrate 10.

  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 15 has a transmission characteristic corresponding to the wavelength, and an infrared cut filter that blocks light in the infrared region (including the near infrared region) is used here. The filter drive device 30 inserts or removes the optical filter 15 on the optical path by rotating and sliding the optical filter 15 via the drive lever 31, and is configured around a motor.

  The optical filter 15 is formed in a thin film (film shape) having a thickness of 0.25 mm or less, and is inserted in a slight gap between the two diaphragm blades 12 and 13. It is provided so that it can slide along. By being sandwiched between the two diaphragm blades 12 and 13 in this way, the optical filter 15 can slide smoothly with the surface of the diaphragm blades 12 and 13 as a guide surface, and is stable while being thin. Insertion / removal operation is possible.

FIG. 2 is a schematic diagram of a cross-sectional structure of the optical filter 15.
This optical filter 15 is formed by using a plastic thin plate 151 having a high heat resistance temperature as a filter base material, and forming multilayer films 152 and 153 having substantially the same thickness on both front and back surfaces (A surface and B surface) by vapor deposition or sputtering. Is. As a material for the plastic thin plate 151, a norbornene-based resin is optimal in terms of optical characteristics and dimensional stability. Since the norbornene-based plastic thin plate 151 has a heat resistance of 130 ° C. or higher, for example, by performing vapor deposition under an atmospheric temperature up to about 120 ° C., the multilayer film 152 is in a stable state without causing deformation. , 153 can be formed.

  Here, by setting the thicknesses of the multilayer films 152, 152 on the front and back sides to be substantially equal, it is possible to maintain a good balance between the front and back sides, and to prevent warping of the optical filter 15 due to temperature changes, etc. Therefore, it is possible to prevent peeling of the deposited film. Further, it is possible to guarantee the stability of the operation when sliding.

FIG. 3 shows an example of the film configuration of the multilayer films 152 and 153. (A) shows an example of film formation by vapor deposition, and (b) shows an example of film formation by sputtering. In the case of vapor deposition (a), as an example, TiO ₂ and SiO ₂ are alternately formed (for example, 38 layers) to form multilayer films 152 and 153 having a thickness of 4 to 5 μm on one side. As a vapor deposition method, it is possible to adopt a method in which a material is melted with an electron beam at an atmospheric temperature of 120 ° C. or lower and vapor-deposited on a plastic thin plate attached to the upper dome of the vapor deposition apparatus.

In the case of sputtering of (b), as an example, Nb ₂ O ₅ and SiO ₂ are alternately formed by RF sputtering (for example, 30 layers) to form multilayer films 152 and 153 having a thickness of about 3 μm on one side. ing. The sputtering can be performed at a low ambient temperature of about 60 ° C.

  As shown in FIG. 4, the optical filter 15 is manufactured by first preparing the plastic thin plate 151 of (a), then (b) performing film formation on the front and back surfaces thereof, and (c) applying it to the press facility. Then, it is preferable to go through a procedure of press-cutting into a predetermined shape and thereby obtaining a finished product (optical filter) of (d).

  As shown in FIG. 1, the press-cut optical filter 15 includes a substantially circular filter main body portion 15 h that covers the optical path of the diaphragm substrate 10, and a crank-shaped lever portion 15 a that extends from the filter main body portion 15 h. Have. The bent portion of the lever portion 15a is provided with a through hole (shaft hole) 15b for rotatably supporting the filter, and the driving pin 30a of the filter driving means 30 is engaged with the distal end side of the lever portion 15a. A long hole (engagement hole) 15c is provided.

  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 light transmittance in the infrared region has a spectral transmittance characteristic substantially equal to the light transmittance 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. 6).

  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.

  As described above, in the optical filter 15 arranged between the two diaphragm blades 12 and 13 that slide linearly in this way, the filter main body portion 15h that blocks the optical path has the through holes 12e of the diaphragm blades 12 and 13, respectively. , 13e is formed in a substantially circular shape slightly larger than 13e, and has a crank-shaped lever portion 15a extending outward at one end thereof.

  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 15 protrudes 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 protrudes in the vicinity of the support shaft 10c. ing.

  The optical filter 15 is rotatably supported along the surfaces of the diaphragm blades 12 and 13 around the support shaft 10c by fitting a through hole 15b provided in the bent portion of the crank lever portion 15a to the support shaft 10c. Has been. Further, the drive pin 31a of the filter driving device 30 is engaged with the long hole 15c provided on the tip end side of the crank lever portion 15a. Thus, when the filter driving device 30 is driven, the rotation of the drive pin 31a is performed. By the movement, the optical filter 15 is rotated about the support shaft 10c, whereby the optical filter 15 is inserted into or removed from the optical path (the optical filter 15 is inserted into or removed from the optical path). )

  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 drive device 30 that drives the optical filter 15 to and from the optical path will be described in detail.
Even if the filter drive device 30 stops energization of the motor, the optical filter 15 is moved to the first position on the optical path (filter use position) or the second position off the optical path (filter non-use position). A filter holding function (filter holding means) for positioning and holding is provided.

  The filter holding function means that the optical filter 15 is located on the first position side from the intermediate position between the first position (filter use position) on the optical path and the second position (filter non-use position) deviated from the optical path. In this case, the optical filter 15 is biased to the first position side by the magnetic force, and as a result, the optical filter 15 is held at the first position, and the optical filter 15 is located on the second position side from the intermediate position. At this time, the optical filter 15 is biased to the second position side by a magnetic force, and as a result, the optical filter 15 is held at the second position.

  In this embodiment, the function of holding the optical filter 15 at either the first position or the second position (filter holding function = filter holding means) is provided in the rotor of the motor that drives the optical filter 15. The permanent magnet and a magnetic piece that generates an attractive force between the N pole or the 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. 5A, 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 30a fitted on the coil bobbin 35, and the like are included. Here, the yoke 30a, 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 15 is coupled to a distal end portion that protrudes to the outside. A soft magnetic piece 37 is arranged between the inside of the yoke 30 a of the stator and the rotor 32. As shown in FIG. 5 (a), the soft magnetic piece 37 has an N of the rotor 32 when the drive lever 31 is operated so that the optical filter 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 pole and the S pole, and generates a suction force between the N pole or the S pole of the rotor 32, thereby performing a function of applying a rotational biasing force to the rotor 32. .

  FIG. 5B shows the rotational position of the rotor 32 when the optical filter 15 reaches the second position (position off the optical path) as a result of the rotor 32 swinging in the direction of arrow (A). . 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 15 is held in the second position.

  FIG. 5C shows the rotational position of the rotor 32 when the optical filter 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 15 is held in the first position.

  Therefore, the optical filter 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 required in this state, so heat generation due to energization is prevented. It 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 15 is obtained by using the permanent magnet of the rotor, so that the soft magnetic piece 37 is simply arranged at a predetermined position. A simple configuration can be obtained.

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 15 is rotated and slid about the support shaft 10 c by the rotation, and the optical filter 15 is moved on the optical path. Can be inserted and removed.

  Since the optical filter 15 in this case is an infrared cut filter, the infrared region of the photographing light can be cut by positioning the optical filter 15 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.

  That is, when it is assumed to be mounted on a CCTV camera, in this type of conventional diaphragm device, the diaphragm aperture is opened on the diaphragm blade in order to widen the control range of the amount of light during monochrome photography at night when no infrared cut filter is inserted. Generally, an ND filter located above is pasted. However, a normal ND filter tends to be in a state where the transmittance for infrared light is increased, that is, a so-called missing state. For this reason, infrared light at the time of monochrome photography cannot be suppressed to the same extent as visible light, the amount of transmitted infrared light is larger than that of visible light, and a subject portion with strong infrared light is bright. Therefore, the captured image is difficult to see. In this respect, the diaphragm device 1 is configured to reduce the amount of transmitted infrared light to the same extent as the light in the visible region by using the ND filters 12f and 13f. 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.

In the present diaphragm device 1 capable of obtaining such an action, various effects as described below can be obtained.
That is, the optical filter 15 is formed into a thin film, and is disposed on the one plate surface (upper surface) side of the diaphragm substrate 10 together with the diaphragm blades 12 and 13 so as to be slidable along the diaphragm blades 12 and 13. The configuration of the diaphragm device 1 can be simplified.

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

  This is because the optical filter 15 is made of a heat-resistant plastic thin plate 151 instead of glass or quartz material, and multilayer films 152 and 153 having substantially the same thickness are formed on both the front and back surfaces by vapor deposition or sputtering. It can be said that this is possible because a thin film (film) filter is used.

  That is, the optical filter 15 can be made lightweight and can be made extremely thin. Moreover, it is hard to break and easy to handle. In addition, since the shape can be freely determined by a mass-productive method such as press cut, even if it does not fit into a movable frame that leads to weight increase or volume increase, direct shape processing and hole processing are performed as described above, It can be easily assembled in a movable manner. In addition, since the multilayer films 152 and 153 having the same thickness are formed on both surfaces, warpage and peeling of the film hardly occur. Even if these characteristics are slidably incorporated in the diaphragm device 1, a stable and reliable sliding operation can be ensured, and an increase in volume and weight can be suppressed, and the entire diaphragm device 1 can be made compact. It is useful.

  Further, since the thickness of the optical filter is set to 0.25 mm or less, the optical path length difference due to the presence or absence of the optical filter 15 can be almost eliminated, and the optical design in consideration of the focus shift can be made unnecessary. . That is, it is not necessary to use a dummy filter for adjusting the optical path length, and the size and weight can be reduced including the drive system.

  Therefore, the optical filter 15 can be integrated into the optical path so that it can be freely inserted and removed, but the entire diaphragm device 1 can be made compact (particularly thin), and can be easily incorporated into a lens barrel and the like. It can greatly contribute to the light weight and downsizing of cylinders.

  Further, the method of sliding the optical filter 15 along the diaphragm blades 12 and 13 may be a linear movement type or a rotary type. However, in the diaphragm device 1, the axis provided at the end of the diaphragm substrate 10 is the center. It is pivoting. By doing so, the optical filter 15 can be directly rotated and slid without being attached to a holder or the like, and the drive system of the optical filter 15 can have a simple space-saving structure. In addition, the optical filter 15 can be driven without difficulty in the small gap between the aperture blades 12 and 13 by using the rotation type (rotation slide type).

  Further, in this diaphragm device 1, the diaphragm driving means 20 and the filter driving means 30 which are parts having a relatively large volume are provided on the same side with respect to the optical path. That is, the parts (diaphragm driving means 20 and filter driving means 30) having a larger dimension in the thickness direction of the diaphragm substrate 10 are not disposed on both sides of the optical path, but are collectively disposed on one side of the diaphragm substrate 10. Since it is, the part on the opposite side can be made thinner. Accordingly, when the diaphragm device 1 is assembled to the lens barrel, the driving device is not obstructed, and the thinned portion is first inserted into the lens barrel from the side while the diaphragm device 1 is inserted into the lens barrel. It can be easily assembled to the lens barrel and can be easily attached to a lens barrel or the like.

FIG. 6 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.

  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 15 may be disposed in the gap between one diaphragm blade and the diaphragm substrate.

It is a disassembled perspective view of the aperture device equipped with the optical filter of the embodiment of the present invention. It is a schematic diagram of the cross-sectional structure of the optical filter. It is a figure which shows the example (a) and (b) of the film | membrane structure of the same optical filter. It is a figure which shows the example of a manufacture procedure of the same optical filter. FIG. 6A is a diagram illustrating a configuration of a filter driving device of the diaphragm device, where (a) is when the optical filter is at an intermediate position between a first position (position on the optical path) and a second position (position off the optical path). FIG. 5B is a diagram illustrating a state when the optical filter is at the second position (position off the optical path), and FIG. 5C is a diagram illustrating the optical filter at the first position (position on the optical path). It is a figure which shows a state when there exists in (). It is a perspective view used for explanation in the case of assembling the diaphragm device from the side to a lens barrel. 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 | restriction apparatus 10 Diaphragm board | substrate 12,13 Diaphragm blade 12f, 13f ND filter 15 Optical filter 151 Plastic thin plate 152,153 Multilayer film 15h Filter main-body part 15a Lever part 15b Through-hole (shaft hole)
15c Long hole (engagement hole)
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 (11)

For an aperture device that is slidably mounted along a plate surface of an aperture substrate having an opening that forms an optical path, and is inserted into or removed from the optical path by being slid by a filter driving means. In the optical filter of
For a diaphragm device characterized in that a plastic thin plate having a heat-resistant temperature capable of film formation by vapor deposition or sputtering is used as a filter substrate, and multilayer films having substantially the same thickness are formed on both front and back surfaces by vapor deposition or sputtering. Optical filter. An optical filter for a diaphragm device according to claim 1,
An optical filter for a diaphragm device, wherein a thin plate of norbornene resin is used as the plastic thin plate. An optical filter for a diaphragm device according to claim 1 or 2,
An optical filter for an aperture device, which is an infrared cut filter that blocks light in an infrared region having a thickness of 0.25 mm or less. An optical filter for a diaphragm device according to any one of claims 1 to 3,
It has a substantially circular filter main body that is large enough to cover the optical path of the diaphragm substrate, and a crank-shaped lever that extends from the filter main-body, and the filter rotates at the bent portion of the crank-shaped lever. A shaft hole for freely supporting is provided, and an engagement hole for engaging the drive pin of the filter driving means is provided on the tip side of the lever portion, and the overall shape is a multilayer film on the plastic thin plate. An optical filter for a diaphragm device, which is processed by press-cutting a formed filter material.   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 according to any one of claims 1 to 4 is used as an optical filter, and the optical filter is arranged on one plate surface side of the diaphragm substrate and is slidable along the diaphragm blades. A diaphragm device characterized by that. The aperture device according to claim 5,
Two diaphragm blades are provided in a stacked state, and the optical filter is disposed between the two diaphragm blades. The diaphragm device according to claim 5 or 6,
The optical filter is rotatably supported on a shaft provided at an end portion of the diaphragm substrate, and is rotated about the shaft so that the optical filter is inserted into or removed from the optical path. A diaphragm device characterized by being a thing. The diaphragm device according to any one of claims 5 to 7,
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 5 to 8,
The filter driving means moves the optical filter to the first position when the optical filter 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 at the second position by magnetic force when the optical filter is on the second position side with respect to the intermediate position. The aperture device according to claim 9, wherein
The filter holding means is adjacent to the permanent magnet when the optical magnet is operated to an intermediate position between the first position and the second position, and a permanent magnet provided on a rotor of a motor that drives the optical filter. And a magnetic piece that is arranged at an equal distance from the north and south poles and that generates an attractive force between the north and south poles and thereby gives a rotational biasing force to the rotor. Squeezing device. The diaphragm device according to any one of claims 5 to 10,
An ND filter different from the optical filter is provided in a through hole portion that forms the aperture opening of the aperture blade, and this ND filter has a transmittance in the infrared region substantially equal to a transmittance in the visible region. A diaphragm device having spectral transmittance characteristics.

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