JP2002189238A - Diaphragm device for cctv camera lens and diaphragm device unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact diaphragm device for a CCTV camera lens provided with a diaphragm and the mechanism part of an optical filter in a lens barrel and capable of regulating transmitted light quantity to infrared light at the time of photographing at night. SOLUTION: In this diaphragm device for the CCTV camera lens, the optical filter and the diaphragm are movably provided along on both sides of a diaphragm unit base plate, and all the elements including the optical filter, a diaphragm driving means for driving a diaphragm and a filter driving means are arranged in the lens barrel. An infrared cut filter intercepting light in an infrared region is used as the optical filter, and an ND filter having spectral transmittance characteristic that the transmittance of an infrared region is nearly equal to or under the transmittance of a visible light region or spectral transmittance characteristic that the light in the infrared region is intercepted is stuck to a light transmitting part where a diaphragm aperture is formed on a diaphragm blade.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CCTV (surveillance camera system) equipped with an optical filter such as an infrared cut filter.
The present invention relates to a diaphragm device for a lens. Furthermore, the present invention relates to a lens aperture device for a day and night surveillance camera system that can be practically used from a visible light wavelength range (about 400 to 700 nm) to a near infrared wavelength range (about 700 to 1000 nm).

[0002]

2. Description of the Related Art As a day and night surveillance camera system, a color image pickup device (CCD) of a camera body forms a color image by forming light in a visible light region during the daytime.
2. Description of the Related Art There is known a system in which, at night, in addition to light in a visible light region, light in a near-infrared light region is imaged to perform monochrome photography and project a monitoring image on a TV monitor. In this system, in the daytime imaging, color imaging is performed based on only light in the visible wavelength range by positioning a near-infrared cut filter in front of the image sensor (in the body or in the lens barrel). At the time of monochrome shooting at night, the filter is removed from the front of the image sensor, and light in the infrared wavelength range and the visible wavelength range is detected as a monochrome image.

FIGS. 9A and 9B are diagrams showing the configuration of a conventional CCTV camera provided with an infrared cut filter. The infrared cut filter 22 is provided in the camera body 10 as shown in FIGS. 9A and 9B.
In FIG. 9A, since the infrared cut filter 22 is arranged on the optical path, the light incident on the lens barrel 18 is incident on the camera body 10 via the aperture device 21 ′, and the infrared power filter 22 And reaches the CCD 11 and is projected as a subject image. On the other hand, in FIG. 9B, since the infrared cut filter 22 has been removed from the optical path, the light that has entered the lens barrel 18 enters the camera body 10 via the aperture device 21 ′, and the infrared cut filter has been removed. The light is projected onto the CCD 11 without passing through the CCD 22. The aperture device 21 'in the lens barrel 18 is driven by an aperture device actuator 24 such as a galvanometer provided in the lens barrel 18 to adjust the size of the opening. On the other hand, the infrared cut filter 22 in the camera body 10 is
9 (a) and 9 (b), driven by an infrared cut filter actuator 25 'such as a motor provided in the inside of the camera.
Are disposed on the optical axis L as shown in FIG.

However, the camera body 10 and the lens barrel 18
In a CCTV camera or the like in which the camera is integrated, it is difficult to provide a unit for an infrared cut filter in the camera body because the camera body itself is small.

In the conventional aperture device, an ND filter located above the aperture opening is attached to the aperture blade in order to widen the control range of the amount of light during nighttime monochrome photography without inserting the infrared cut filter 22. The configuration is known. However, the conventional ND filter is in a state where transmittance with respect to infrared light is increased, that is, a so-called missing state. FIG. 10 shows an example of the spectral transmittance characteristic of this conventional ND filter. With an ND filter having such spectral transmittance characteristics, the total amount of light including visible light and infrared light during monochrome photographing cannot be suppressed uniformly, and the amount of transmitted infrared light becomes larger than that of visible light. . As a result, the subject portion where infrared light is strongly reflected is brightly displayed, and an image that is difficult to see is obtained.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a small-sized aperture device for a CCTV camera lens in which a diaphragm and a mechanism of an optical filter are provided in a lens barrel based on the above problem awareness. Another object of the present invention is to provide a diaphragm device capable of regulating the amount of transmitted light up to infrared light during nighttime photographing.

[0007]

SUMMARY OF THE INVENTION A diaphragm device for a CCTV camera lens according to the present invention includes a diaphragm provided in a lens barrel, a plate-shaped diaphragm unit substrate for holding the diaphragm, and a size of the aperture of the diaphragm. A diaphragm driving means for adjusting, an optical filter for blocking or transmitting light according to the wavelength, and a filter driving means for inserting and removing the optical filter on the optical path, the diaphragm and the optical filter are provided on the diaphragm unit substrate. The diaphragm, the diaphragm unit substrate, the diaphragm driving unit, the optical filter, and the filter driving unit are all disposed in the lens barrel.

The diaphragm has two diaphragm blades, and the optical filter is provided in at least one opening of a flat plate-shaped filter fixing plate having two openings, and the two diaphragm blades and the filter fixing plate are respectively provided. 1st aperture unit board
And it is preferable to be arranged along the second surface. Thereby, the aperture device can be made thinner and smaller.

The filter driving means has a latching mechanism for holding the position of the optical filter when the optical filter is inserted on the optical path and the position of the optical filter when the optical filter is removed from the optical path. Is preferred. Accordingly, the position of the optical filter can be held by the latching mechanism except when the filter driving unit is driven to remove and insert the filter, so that the power consumption of the filter driving unit (actuator) can be reduced. it can.

In order to improve the durability of the diaphragm device, reduce the cost, simplify the circuit configuration and further reduce the size,
It is preferable to use a galvanometer for the filter driving means.

The optical filter is, specifically, an infrared cut filter that blocks light in an infrared region. Infrared castles
This is a wavelength range of about 700 nm to 1000 nm.

[0012] The diaphragm blade may be provided with another optical filter in the light transmitting portion forming the diaphragm aperture. As this other optical filter, an ND filter is preferable. In particular, in order to reduce infrared light during nighttime imaging, this ND filter has a spectral transmittance characteristic in which the transmittance in the infrared region is substantially equal to or less than the transmittance in the visible light region, or the light in the infrared region. It is preferable to use a filter having a spectral transmittance characteristic that blocks the light. Further, it is preferable that the surface reflectance of the ND filter is about 2% or less.

According to another aspect of the present invention, there is provided a diaphragm device unit provided in a lens barrel of a CCTV camera having a color image sensor, the diaphragm unit substrate having a flat plate portion having a photographing opening; It is provided with a pair of openings corresponding to the photographing opening, and one of the openings has an infrared cut filter that blocks light in the infrared region, and is provided on one of the front and back surfaces of the flat plate portion of the unit substrate. A filter fixing plate that is movably supported, and two diaphragm plates that are movably supported on the other surface of the flat plate portion and that change the size of the diaphragm opening that overlaps the shooting aperture according to the relative movement position; An ND filter attached to at least one of the two aperture plates so as to be positioned above the aperture opening, and a pair of actuators supported on a diaphragm unit substrate with a flat plate portion interposed therebetween are provided. No One of the tutors is an infrared cut filter actuator that reciprocates the filter fixing plate and selects one of the openings to be positioned on the photographing opening, and the other has the two diaphragm plates in opposite directions. It is characterized in that it is a diaphragm drive actuator that moves to change the diaphragm aperture. The infrared region has a wavelength of about 70
This is a wavelength range from 0 nm to 1000 nm.

As the ND filter, a filter having a spectral transmittance characteristic in which the transmittance in the infrared region is substantially equal to or less than the transmittance in the visible light region, or a spectral transmittance characteristic for blocking light in the infrared region is used. Thus, an image which is easy to see by monochrome shooting at night can be obtained. The surface reflectance of the ND filter is about 2
% Is preferable. The ND filter is
It is preferable that the filter is formed by depositing a metal thin film on a resin base.

When the pair of actuators are fixed to the aperture unit substrate at substantially symmetrical positions with respect to the photographing aperture of the aperture unit substrate (180 ° opposed arrangement), the size is small and the balance is good.

In the pair of openings of the filter fixing plate, the opening on the side not provided with the infrared cut filter can be provided with a translucent parallel plane plate. The infrared cut filter actuator positions the infrared cut filter in front of the color image sensor during daylight photographing, and the translucent parallel flat plate in front of the color image sensor during nighttime photographing. The deviation can be corrected.

Preferably, the aperture device unit for a CCTV camera includes a latching barrel for latching the filter fixing plate when one and the other of the pair of openings are positioned on the photographing opening.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1A and 1B are diagrams schematically showing the structure of a diaphragm device according to an embodiment of the present invention. FIG. 1A shows a state in which an infrared cut filter (optical filter) is inserted on an optical axis (optical path).
(B) shows a state in which the infrared cut filter has been removed from the optical axis (optical path).

In the CCTV camera of the present embodiment, the camera body 10 and the lens barrel 18 are integrally formed.
An imaging device such as a CCD 11 is mounted on the camera body 10, and an imaging lens (not shown) and an aperture device unit (aperture device) 20 are provided in the lens barrel 18. The aperture device unit 20 includes an aperture 21, an infrared cut filter 22, an aperture unit substrate 23, an aperture galvanometer (an actuator for an aperture device) 24, a filter galvanometer (an actuator for an infrared cut filter) 25, and the like. Aperture galvanometer 2
4 is used for driving the diaphragm 21, and the filter galvanometer 25 is used for driving the infrared cut filter 22.

In FIG. 1A, light enters the lens barrel 18 via an imaging lens (not shown) from the left-hand direction in the figure, passes through a diaphragm 21 and an infrared cut filter 22, and then enters a CC.
An image is formed on the imaging surface of D11. At this time, since the light of the infrared wavelength region is selectively cut (blocked), only an image of light in the visible wavelength region is formed on the imaging surface of the CCD 11.
The video at this time is acquired as a color video. on the other hand,
In FIG. 1B, since the infrared cut filter 22 is retracted from the optical axis L by the filter galvanometer 25, the light incident on the lens barrel 18 is coupled to the CCD 11 only through the diaphragm 21. Imaged. That is, CCD1
In 1, light in the infrared wavelength range as well as light in the visible wavelength range is received. At this time, the image captured by the CCD 11 is acquired as a monochrome image. The aperture unit substrate 23 is provided with a circular opening sufficient to allow the incident light to pass therethrough as described later, and the light passes through the opening through the CCD.
It reaches the light receiving surface of No. 11.

The diaphragm 21 has two diaphragm blades (see FIG. 2).
Is a conventionally known stop composed of. That is, the diaphragm blades are formed of thin metal plates having different shapes, and an opening for the diaphragm is formed by stacking these metal plates. The size of the opening is adjusted by shifting the arrangement of the two diaphragm blades along the unit substrate 23.

FIGS. 2A and 2B show two aperture blades 3.
The plane shapes of 0a and 30b are shown. Each of the aperture blades 30a and 30b has a substantially V-shaped notch forming portion 31.
a and 31b are formed. A substantially fan-shaped member drawn by a broken line is a thin and lightweight N based on a photographic film.
The D filters 32a and 32b are fixed at positions indicated by broken lines with an adhesive or the like. ND filter 32a,
As for 32b, only one may be bonded to the aperture blades 30a, 30b. Arms 30a and 3b extending rightward in the figure
Is for transmitting the power of the aperture galvanometer 24 to the aperture blades. Slots 34a and 34b are formed at the distal ends of the arms 33a and 33b. The slots 34a and 34b are engaged with pin-shaped projections provided on a drive lever of the aperture galvanometer 24.

FIGS. 3A and 3B show the planar shape of the filter fixing plate 40 to which the infrared cut filter 22 is attached.

The filter fixing plate 40 is, for example, a substantially rectangular thin metal plate having an arm 43 extending leftward in the figure, and has a long side in the longitudinal direction of the arm 43. In the filter fixing plate 40, two circular openings 41 and 42 having the same size along the long side are formed.
It is covered by an infrared cut filter 22 indicated by a broken line. In the embodiment shown in FIG. 3A, the circular opening 42 is a plain simple hole, and nothing is provided. The infrared cut filter 22 is fixed around the circular opening 41 of the filter fixing plate 40 with four claws 22a and an adhesive.
A slot 44 is formed at the distal end of the arm 43, and is engaged with a pin-shaped projection provided on a driving lever of the filter galvanometer 25 as described later. The diameter of the circular openings 41 and 42 is determined by the aperture unit substrate 2
Circular opening (photographing opening) 51 provided in 3 (see FIG. 4)
Is substantially equal to the diameter of the aperture and corresponds to the largest stop aperture (photographing aperture) in the present embodiment.

The infrared cut filter 22 is, for example, as shown in FIG.
As shown in the spectral transmittance characteristic curve X shown in FIG.
It has a spectral transmittance characteristic of cutting infrared light of m or more.
More specifically, from the visible light range to near-infrared light (about 700 nm
It has a spectral transmittance characteristic of a transmittance of about 5% or less for light in a wavelength region of up to about 1000 nm. The infrared cut filter 22 is formed as, for example, a deposition interference filter formed of a multilayer film.

On the other hand, the ND filters 32a and 32b have a spectral transmittance characteristic in which the transmittance of infrared light is substantially equal to or less than the transmittance in the visible light region, as shown in the spectral transmittance characteristic Y of FIG. have. This ND filter 32a,
32b is formed, for example, by depositing a metal thin film composed of a multilayer film on a resin base. In this way, if the infrared light region has a spectral transmittance characteristic substantially equal to the transmittance in the visible light region, it is possible to limit the amount of transmitted light without impairing the color characteristics when performing daytime color shooting. In the case of performing monochrome photographing, it is possible to sufficiently increase the F-number even in the infrared wavelength band having sensitivity to limit the amount of transmitted light.

The spectral transmittance characteristics of the ND filters 32a and 32b may be such that the infrared region is cut as shown by a transmittance curve Z in FIG. If monochrome imaging is performed with the ND filters 32a and 32b having such characteristics positioned on the imaging optical path, a phenomenon in which a portion having a high reflectance of infrared light is reflected brightly and looks as if it were infrared light imaging does not occur. .

It is preferable that the ND filters 32a and 32b have a surface reflectance of about 2% or less. Given such a low reflectance, the ND filter 3
2a, 32b, the surface reflection of the ND filter 32 is small.
Ghosts, flares, etc. are not likely to occur due to light reflected on the surfaces a, 32b.

Next, a diaphragm device (a diaphragm device unit) of the present embodiment will be described with reference to FIGS. The aperture unit substrate 23 has a flat plate portion 50, and the flat plate portion 5
0, the aperture blades 30a, 30b
Are arranged side by side in an overlapping state, and galvanometers 24 and 25 are attached. On the other hand, on the back surface (second surface) of the flat plate portion 50 of the aperture unit substrate 23,
The filter fixing plate 40 is arranged along. Flat plate part 50
A circular opening 51 for passing incident light is formed in the vicinity of a substantially central portion (a portion where the optical axis L of the imaging optical system passes). The galvanometers 24 and 25 are connected to the aperture unit substrate 2
3 are disposed substantially symmetrically with respect to the photographing opening 51 (180 ° opposed arrangement).

A thick frame portion 54 is provided around the flat plate portion 50.
Are formed. The frame unit 54 includes the aperture unit substrate 2
Two projections 55 are provided for fixing 3 to a support member (not shown) in the lens barrel. A hole 55a for passing a screw is formed at the center of the protruding portion 55, and the aperture unit substrate 50 is fixed in the lens barrel by a screw inserted into the two holes 55a. Also, the aperture blades 30a and 30b and the filter fixing plate 40 disposed on the flat plate portion 50 are provided on the front and rear frame portions of the flat plate portion 50, respectively.
However, there is provided a claw member 56 for supporting the flat plate portion 55 so as to be slidable along each surface and not to be separated from each surface. As shown in FIGS. 4A and 4B, in the present embodiment, four claw members 56 are provided on the front side and three claw members 56 on the back side.

The aperture galvanometer 24 is attached to the base 52 on the right side of FIG. 4 (the upper side of FIGS. 5 and 6) at a position indicated by a circular broken line. On the other hand, the filter galvanometer 25 is attached to a position indicated by a circular dashed line on the base 53 on the left side (lower side in FIGS. 5 and 6) of FIG.
In the centers of the circular broken lines drawn in 2, 53, shaft holes 52a, 5a for pushing the rotating shafts of the galvanometers 24, 25 are provided.
3a are provided respectively.

In the side view of FIG. 4C, the lower side of the figure corresponds to the front side, and the upper side corresponds to the back side. That is, the left and right base portions 52 and 53 are provided at positions lower than the flat plate portion 50 in the drawing. The back sides of the pedestals 52 and 53 have concave spaces 52b and 5
3b is formed, and the rotating shaft 24 of each galvanometer is formed.
c and 25c reach the concave air holes 52b and 53b through the shaft holes 52a and 53a. Drive levers 24a, 24b and 2 attached to the rotation shaft of each galvanometer
5a is accommodated in each of the concave spaces 52b and 53b.

An opening 52c is formed in a side surface of the base portion 52 on which the diaphragm galvanometer 24 is mounted, on the side of the flat plate portion 50. The flat plate portion 50 ends before the base portion 52 and forms an end face 50a. That is, the concave space 5
2b communicates with the space on the surface side of the flat plate portion 50, and the arms 33a and 33b of the aperture blades 30a and 30b pass through the opening 52c and are housed in the concave space 52b.
a, 24b and the slot 3
4a and 34b are engaged respectively. On the other hand, the arm 34 of the filter fixing plate 40 is connected to the pin-like projection 25d of the drive lever 25a housed in the concave space 53b via the slot 44 provided at the tip.

Rotation shaft 24c of aperture galvanometer 24
The drive levers 24a and 24b attached to the
7, is urged around the rotation shaft 24c (counterclockwise in FIG. 6). 5 and 6 show the arrangement when the aperture galvanometer 24 is not driven.
Only the urging force of the spring 57 acts on the drive levers 24a and 24b, and the drive levers 24a and 24b are at the most rotated counterclockwise (clockwise in FIG. 7) in FIG. At this time, the aperture blade 30a is located at a position closest to the base 52 side, and the aperture blade 30b is located farthest from the base 52 side. That is, the two substantially V-shaped notch forming portions 31a and 31b overlap at a substantially central portion of the opening 51 to form a substantially square aperture opening (optical path). At this time, as shown by the dashed line in FIG. 5, approximately fan-shaped ND filters 33a and 33b are positioned on the square aperture opening to attenuate the amount of light passing through the aperture. If the ND filters 33a and 33b have spectral transmittance characteristics such as Y and Z in FIG. 8, the infrared light is blocked.

When the aperture galvanometer 24 is driven and the drive levers 24a and 24b are rotated clockwise in FIG. 6 (counterclockwise in FIG. 5), the aperture blade 30a is moved away from the base 52. And the diaphragm blade 30b is mounted on the base 52.
Is moved in the direction of. Accordingly, the opening formed by the two substantially V-shaped notch forming portions 31a and 31b is
a, 24b, and increases with the rotation of the drive lever 24.
When the rotation of a and 24b reaches the position where the rotation of clockwise (in FIG. 6) becomes maximum, the circular opening 51 is completely included in the opening formed by the two substantially V-shaped notch forming portions 31a and 31b. At this time, the ND filters 33a and 33b are both outside the circular opening 51, and the size of the diaphragm is equal to the circular opening 51. That is, the ND filters 33a, 33
b retracts from the photographing optical path (circular opening 51).

On the other hand, a base of a latching lever 58 is attached to the rotating shaft 25c of the filter galvanometer 25 in addition to the drive lever 25a. The latching lever 58 is made of, for example, a synthetic resin material such as Delrin (trade name), and has an arc-shaped arm at its tip (free end), and has a tip protruding in the radial direction of the rotating shaft 25c. A latching projection 58a is provided. The latching lever 58 has a spring property due to the bending of the arcuate arm, and the concave space 5 of the base 53 is provided.
Latching fixing grooves 59a, 59b formed in 3b
Together with a latching mechanism. In FIG.
8a is locked in the fixing groove 59a, and at this time, the drive lever 25a of the filter galvanometer 25 is at the counterclockwise rotation end. That is, the filter fixing plate 40 is disposed near the base 53, and the center of the circular opening 42 is the optical axis L.
Is held in a position that matches Thus, in the arrangement shown in FIG.
It is incident on zero.

When the filter galvanometer 25 is driven and the drive lever 25a is rotated clockwise in FIG. 6, the projection 58a of the latching lever 58 is turned on.
Is released from the fixing groove 59a, and is thereafter locked in the fixing groove 59b. This locking position is the clockwise rotation end of the drive lever 25a. At this time, with the rotation of the drive lever 25a, the filter fixing plate 40 is moved in the direction of the pedestal 52, and the center of the circular opening 41 is held at a position corresponding to the optical axis L. That is, the light passes through the infrared cut filter 22 provided in the circular aperture 41 and the camera body 10
Incident on.

As described above, the infrared cut filter 22 is inserted and removed from the optical path in the lens barrel 18 by rotating the filter galvanometer 25 in the normal and reverse directions.

The diaphragm galvanometer 24 and the filter galvanometer 25 have two pairs of electrode terminals 61a and 61b.
And 62a, 62b (see FIG. 5) are provided, respectively. The electrode terminals 61a and 61b are for supplying electric power for driving the galvanometer, and the electrode terminals 61b and 62b are connected to a generator provided in the meter, for example, for detecting the rotation speed of each galvanometer. Terminal. The cords 61 and 62 connected to the respective electrode terminals are led to respective control circuits and the like (not shown).

As described above, according to the present embodiment, the mechanism for inserting and removing the infrared cut filter on the optical path and the two
Since the aperture mechanism using the number of aperture blades is configured as an integrated unit, the mechanism relating to the infrared cut filter can be configured to be smaller, and the infrared cut filter can be housed in the lens barrel. That is, it is not necessary to separately provide a mechanism for driving the infrared cut filter in the camera body, and the space can be efficiently used, so that the size of the camera can be reduced.

In this embodiment, a galvanometer is used as an actuator for driving the diaphragm blade and the filter fixing plate. However, another driving device may be used. But,
The galvanometer is suitable as a small-sized actuator, so that the size of the device can be further reduced. In addition, the durability is improved and the circuit configuration is simplified as compared with the case where the motor is used for a driving device. This also reduces manufacturing costs. Further, by disposing a pair of galvanometers at 180 ° opposite to the aperture unit substrate, a small and well-balanced aperture device unit can be obtained. In the present embodiment, the galvanometer is provided with the generator. However, for example, the galvanometer for the filter may not have the generator.

It is also possible to attach a flat cover member for holding the filter fixing plate and the diaphragm blade on each surface of the diaphragm unit substrate, but if a claw-like member is used as in this embodiment, The thickness of the drawing device can be reduced, and the cost of members can be reduced.

In this embodiment, an infrared cut filter is mounted on the filter fixing plate. However, the type of the filter can be changed according to the use of the camera. Similarly, the aperture plate is provided with an ND filter having a spectral transmittance characteristic as indicated by Y and Z in FIG. 9, but depending on the use of the camera, the spectral transmittance of the aperture plate is determined, including whether or not to provide a filter on the aperture plate. Characteristics can be set freely.

However, for example, X in FIG.
9 is provided with an infrared cut filter having a spectral transmittance characteristic as shown in FIG. 9 and an ND filter having a spectral transmittance characteristic as shown in Y and Z in FIG. It can be suitably used for a CCTV camera that performs.

Further, in the present invention, the configuration of the photographing lens disposed in the lens barrel 18 is not limited. That is, as an imaging lens, a lens system that has been subjected to aberration correction with emphasis on the visible light region has been used in the past, and in the near-infrared light region (nighttime shooting), an infrared cut filter has been used to correct the focus position. Instead, a translucent parallel flat plate of another predetermined thickness has been inserted, but recently, a lens system in which focus movement in daytime shooting and nighttime shooting has been corrected to an allowable range has been proposed. . The present invention may use any type of taking lens. When a translucent parallel flat plate is inserted, as shown in FIG. 3B, a translucent parallel flat plate 22X is inserted into the opening 42 of the filter fixing plate 40 on the side not having the infrared cut filter 22. Can be provided. When this translucent parallel flat plate 22X is used for a lens system in which the focus movement in daytime shooting and nighttime shooting is corrected to an allowable range, the optical thickness (refractive index × thickness) of the infrared cut filter 22 is the same. A translucent parallel flat plate is used. Further, in a lens system in which aberration correction is performed with emphasis on the visible light region, a transparent parallel flat plate having a thickness capable of correcting a focus position in photographing in the near infrared light region (night photographing) is used.

Although the CCTV camera of this embodiment is a camera in which the camera body and the lens barrel are integrally formed, the CCTV camera may have a structure in which the lens barrel and the camera body can be separated.

[0047]

As described above, according to the present invention, it is possible to obtain a small aperture apparatus for a CCTV camera lens in which an aperture and a mechanism of an optical filter are provided in a lens barrel. In addition, by arranging the two diaphragm blades and the filter fixing plate for fixing the optical filter along the front and back surfaces of the diaphragm unit substrate, the diaphragm device can be made thinner and smaller. Furthermore, in a mode in which an ND filter having a transmittance of infrared light that is substantially equal to or less than the transmittance in the visible light region, or an extremely low spectral transmittance characteristic is attached to the diaphragm blade, the color characteristic is not obtained in color photography. It is possible to limit the amount of transmitted light without loss, and in monochrome photography, the total amount of light including visible light and infrared light is sufficiently suppressed, and the phenomenon that the subject part with strong infrared light reflection is bright appears. Can be.

[Brief description of the drawings]

FIG. 1 is a view schematically showing an embodiment of an aperture device of a CCTV camera according to the present invention.

FIG. 2 is a diagram illustrating a planar shape of two diaphragm blades of the diaphragm device.

FIG. 3 is a diagram illustrating a planar shape of a filter fixing plate to which an infrared cut filter is attached.

FIG. 4 is a front view, a back view, and a side view of the aperture unit substrate.

FIG. 5 is a diagram of a diaphragm unit substrate on which diaphragm blades and a filter fixing plate are mounted, as viewed from the front side.

FIG. 6 is a view of a diaphragm unit substrate to which diaphragm blades and a filter fixing plate are attached, as viewed from the back surface side.

FIG. 7 is a side view of the aperture unit substrate to which the aperture blades and the filter fixing plate are attached.

FIG. 8 is a graph illustrating an example of spectral transmittance characteristics of an infrared cut filter and an ND filter used in the diaphragm device of the present invention.

FIG. 9 shows a conventional CC equipped with an infrared cut filter.
It is a figure which shows the structure of the camera for TV typically.

FIG. 10 is a graph showing a spectral transmittance characteristic of a conventional general ND filter.

[Explanation of symbols]

 Reference Signs List 18 lens barrel 21 aperture 22 infrared cut filter 22X parallel plane plate 23 aperture unit substrate 24 aperture galvanometer (actuator) 25 filter galvanometer (actuator) 30a 30b aperture blade 32a 32b ND filter 40 filter fixing plate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03B 9/06 G03B 9/06 11/00 11/00 15/00 15/00 S

Claims (18)

[Claims] An aperture provided in a lens barrel for a CCTV camera, an aperture unit substrate having a flat plate shape for holding the aperture, and an aperture drive for adjusting the size of the aperture of the aperture. Means, an optical filter for blocking or transmitting light according to the wavelength, and filter driving means for inserting and removing the optical filter on the optical path, wherein the stop and the optical filter are arranged along the stop unit substrate. A diaphragm device for a CCTV camera, wherein the diaphragm, the diaphragm unit substrate, the diaphragm driving means, the optical filter, and the filter driving means are all disposed in the lens barrel. 2. The filter according to claim 2, wherein the aperture has two aperture blades, and the optical filter is provided in at least one opening of a flat plate-shaped filter fixing plate having two openings.
A plurality of aperture blades and a filter fixing plate are arranged along the first and second surfaces of the aperture unit substrate, respectively;
2. The CC according to claim 1, wherein the filter driving means selects one of two openings of the filter fixing plate and moves the filter fixing plate on an optical path.
A diaphragm device for TV camera lenses. 3. Latching for holding a position of the optical filter when the optical filter is inserted into the optical path and a position of the optical filter when the optical filter is removed from the optical path. 2. The diaphragm device for a CCTV camera lens according to claim 1, wherein the filter driving means includes a mechanism. 4. The diaphragm device for a CCTV camera lens according to claim 1, wherein the optical filter is an infrared cut filter that blocks light in an infrared region. 5. An aperture device for a CCTV camera lens according to claim 2, wherein the aperture blade is provided with another optical filter in a light transmitting part forming an aperture aperture. . 6. The diaphragm device for a CCTV camera lens according to claim 5, wherein the another optical filter is an ND filter. 7. The diaphragm apparatus for a CCTV camera lens according to claim 6, wherein the ND filter has a spectral transmittance characteristic whose transmittance in an infrared region is substantially equal to or less than transmittance in a visible light region. 8. The CCT according to claim 6, wherein the ND filter has a spectral transmittance characteristic of blocking light in an infrared region.
Aperture device for lens for V camera. 9. The infrared region has a wavelength of about 700 nm to 1 nm.
9. The diaphragm device for a CCTV camera lens according to claim 4, wherein the diameter is 000 nm. 10. The diaphragm device for a CCTV camera lens according to claim 6, wherein a surface reflectance of the ND filter is about 2% or less. 11. The aperture device for a CCTV camera lens according to claim 7, wherein the ND filter is a filter in which a metal thin film is deposited on a resin base. 12. A diaphragm unit provided in a lens barrel of a CCTV camera equipped with a color image pickup device, wherein the diaphragm unit substrate has a flat plate portion having a photographing aperture, The unit substrate has a pair of openings, and one of the openings has an infrared cut filter that blocks light in the infrared region, and is movably supported on one of the front and back surfaces of the flat plate portion of the unit substrate. A filter fixing plate,
Two diaphragm plates movably supported on the other surface of the flat plate portion and changing the size of the diaphragm opening overlapping the photographing aperture according to the relative movement position, and at least one of the two diaphragm plates, N pasted so as to be located on the aperture
A D filter, and a pair of actuators supported on the diaphragm unit substrate with the flat plate portion interposed therebetween;
One of the pair of actuators is an infrared cut filter actuator that reciprocates the filter fixing plate and selects one of the pair of openings to be positioned on the photographing opening, and the other is the two diaphragm plates. A diaphragm device unit of a lens for a CCTV camera, which is a diaphragm driving actuator for relatively moving the diaphragm apertures in opposite directions to change the diaphragm aperture. 13. The ND filter has a spectral transmittance characteristic whose transmittance in an infrared region is substantially equal to or less than a transmittance in a visible light region, or a spectral transmittance characteristic which blocks light in an infrared region. Aperture unit for CCTV camera lens. 14. A diaphragm device unit for a CCTV camera lens, wherein the pair of actuators are fixed to the diaphragm unit substrate at substantially symmetric positions with respect to a photographing opening of the diaphragm unit substrate. 15. A pair of openings of the filter fixing plate which are not provided with an infrared cut filter are provided with a light-transmitting parallel flat plate, and the infrared cut filter actuator is provided with a daylight. An aperture device unit for a CCTV camera lens, wherein the infrared cut filter is positioned in front of the color image sensor at the time of shooting, and the translucent parallel flat plate is positioned in front of the color image sensor at night. 16. A latching mechanism for latching the filter fixing plate when one and the other of the pair of openings are located on the photographing opening.
6. A diaphragm device unit for a CCTV camera lens according to any one of 5. 17. The infrared region has a wavelength of about 700 nm.
17. The semiconductor device according to claim 12, wherein the thickness is 1000 nm.
An aperture device unit for a lens for a CCTV camera according to the above item. 18. The aperture device unit for a CCTV camera lens according to claim 12, wherein the surface reflectance of the ND filter is about 2% or less. 19. The ND filter according to claim 12, wherein the ND filter is a filter in which a metal thin film is deposited on a resin base.
A diaphragm device unit for a lens for a CCTV camera according to any one of the above.