TWI528102B - Diaphragm device, camera and electronic equipment - Google Patents

Description

Aperture device, camera and electronic machine

The present invention relates to an aperture device having a pair of aperture blades, and a camera and an electronic device therewith.

Usually, an imaging device capable of color photography is assembled in a surveillance camera that is used both day and night. Such a surveillance camera switches the shooting mode when the subject is brighter and the subject is darker. Specifically, the color photographing mode is applied to the photographing of a brighter white or the like, and the photographing mode is switched in a manner of applying a monochrome photographing mode at the time of photographing at night when the subject is dark.

Further, in the color photographing mode, an infrared cut filter is disposed in front of the image pickup element (light incident side). Therefore, when photographing is performed in the color photographing mode, light incident from the outside reaches the image pickup element via the infrared cut filter. On the other hand, in the monochrome photographing mode, the infrared cut filter is retracted from the front side of the image sensor. Therefore, when photographing is performed in the monochrome imaging mode, light incident from the outside does not reach the imaging element via the infrared cut filter.

In the various cameras including the above-described surveillance cameras, an aperture device for adjusting the amount of light incident on the camera from the outside (hereinafter referred to as "incident light amount") is incorporated. The aperture device adjusts (appropriates) the amount of incident light by changing the size of the aperture opening existing on the light path of the incident light.

Fig. 8 is an exploded perspective view showing an example of a conventional aperture device. The aperture device 200 is mainly configured to include a diaphragm substrate 201, a pair of diaphragm blades 202 and 203, a filter substrate 204, a blade cover 205, a diaphragm driving unit 206, a filter driving unit 207, and a pair of ND filters. 208, 209.

The diaphragm substrate 201 is slidably movable (slidably) to support the pair of diaphragm blades 202 and 203. Further, the diaphragm substrate 201 supports the diaphragm driving unit 206 and the filter driving unit 207.

The pair of aperture blades 202, 203 form a diaphragm opening in a state of being superposed on each other. This aperture opening is formed by the hole portion 210 formed in one of the aperture blades 202 and the bay portion 211 provided on the other aperture blade 203.

The filter substrate 204 has a filtering function of cutting off light in the infrared region (including the near-infrared region) from the light incident from the outside. Specifically, as shown in FIGS. 9 and 10 , the filter substrate 204 is configured such that an infrared cut filter layer 213 is formed on one surface of the glass substrate 212 . Further, the filter substrate 204 is attached to the frame member 214. Further, the filter unit 215 is constituted by a combination of the filter substrate 204 and the frame member 214.

The blade cover 205 is shielded from the outside by one of the diaphragm substrates 201 and protected by the diaphragm blades 202 and 203.

The diaphragm driving unit 206 moves the pair of diaphragm blades 202 and 203 relatively (hereinafter, simply referred to as “relative movement”). The relative movement of the pair of aperture blades 262, 203 is such that the movement is made in such a direction as to approach or move away from each other.

The filter driving unit 207 moves the filter unit 215 including the filter substrate 204 and the frame member 214. The filter unit 215 is moved by the filter driving unit 207 to advance the filter substrate 204 to the light path of the incident light and to evacuate the filter substrate 204 from the light path of the incident light. Time to proceed.

The ND filters 208 and 209 respectively attenuate the light. As shown in FIG. 11, the ND filter 208 is attached to the edge of the hole portion 210 of one of the aperture blades 202 using an adhesive, and the ND filter 209 is attached to the bay portion of the other aperture blade 203 using an adhesive. The edge of 211.

In the aperture device 200 including the above-described configuration, when the pair of aperture blades 202 and 203 are stacked and attached to the aperture substrate 201, as shown in FIG. 12, the portion where the hole portion 210 and the bay portion 211 are overlapped is An aperture opening 216 is formed. When the diaphragm driving unit 206 is driven on the diaphragm substrate 201, the pair of diaphragm blades 202 and 203 are moved toward or away from each other. As a result, the size of the aperture opening 216 will vary depending on the direction of movement and the amount of movement of the pair of aperture blades 202, 203.

Specifically, when the pair of aperture blades 202 and 203 are moved toward each other (the direction of the arrow of the solid line in FIG. 12), the aperture opening 216 will become larger, and conversely, if a pair of aperture blades 202, When the 203 moves toward the direction away from each other (the direction of the arrow of the broken line in Fig. 12), the aperture opening 216 becomes smaller accordingly. When the pair of aperture blades 202 and 203 are in the closest state, the aperture opening 216 is maximized (full open state), and if the pair of aperture blades 202 and 203 are in the farthest state, the aperture opening 216 Will be the smallest (completely closed state or near fully closed state). Fig. 13 shows a state in which the aperture opening is opened (fully opened), and Fig. 14 shows a state in which the aperture opening is made into a small aperture.

Further, in the diaphragm substrate 201, a filter unit is disposed between the pair of diaphragm blades 202 and 203 (gap portion) so that the filter substrate 204 can advance and retreat (pluggable) with respect to the diaphragm opening 216. 215 (filter substrate 204, frame member 214). When the filter driving unit 207 is driven on the diaphragm substrate 201, the filter substrate 204 is integrated with the frame member 214 and moved. At this time, when the filter substrate 204 is moved to one side, the filter substrate 204 is in a state of proceeding to the light path of the incident light passing through the aperture opening 216. Further, when the filter substrate 204 is moved to the other side, the filter substrate 204 is retracted from the optical path.

In the aperture device 200 that performs this operation, the filter substrate 204 and the ND filters 208 and 209 are assembled for different purpose of use. That is, the filter substrate 204 is assembled to prevent color deviation (image redness) caused by the incident of infrared light when photographing in a color photographing mode suitable for daylight or the like. On the other hand, the ND filters 208 and 209 are used to finely control the amount of incident light even when the aperture opening 216 is reduced in order to prevent the signal of the pixel of the imaging element from being saturated during imaging such as daylight. And assembly.

As such an aperture device, for example, those described in Patent Document 1 are known. In addition, it is known that the infrared cut filter and the ND filter are integrally formed as a lens for monitoring a camera (see Patent Document 2).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-17594

[Patent Document 2] Japanese Patent Laid-Open No. Hei 5-110938

In the above-described aperture device 200, the filter substrate 204 and the ND filters 208 and 209 are separately mounted for the purpose of use.

In other words, the filter substrate 204 must be advanced to the light path of the incident light during imaging such as daylight, and must be retracted from the light path of the incident light during shooting at night or the like. Therefore, the filter substrate 204 is moved integrally with the frame member 214 by the filter member substrate 204 being attached to the frame member 214.

On the other hand, in the ND filters 208 and 209, when the aperture opening 216 is reduced, it is necessary to effectively function the ND filters 208 and 209. Therefore, the ND filters 208 and 209 are attached to the pair of aperture blades 202 and 203, and the respective aperture blades 202 and 203 and the ND filters 208 and 209 are integrally moved.

However, in the conventional aperture device 200, there are the following drawbacks.

That is, if the aperture opening 216 is gradually reduced from the fully open state by the relative movement of the pair of aperture blades 202, 203, as shown in FIG. 12 above, a pair of ND filters 208, 209 will start to overlap. Hehe. In this case, the light passing through the aperture opening 216 is divided into: light passing through a portion of the ND filter 208 or the ND filter 209 which is separately present; superimposed by the two ND filters 208, 209 Part of the light; and a portion of the light passing through the ND filters 208, 209. Therefore, a partial difference occurs in the amount of light passing through the aperture opening 216.

As a result, in the image captured by the imaging element (not shown) (in one screen), three kinds of luminance distributions are generated without depending on the brightness of the subject. Therefore, characteristics such as light shielding are deteriorated. Further, since the adjustment of the aperture opening 216 cannot be performed stably, there is a risk of causing a hunting phenomenon. In particular, in a state where the aperture opening 216 is reduced, an oscillation phenomenon is apt to occur.

Further, in the conventional aperture device including a pair of aperture blades, there is also a type in which an ND filter is attached to only one of the aperture blades. However, in this type of aperture device, the position of the ND filter is biased to one side with respect to the center of the aperture opening. Therefore, defects such as shading are inevitably generated.

A main object of the present invention is to provide a diaphragm device that can change a diaphragm opening by using a pair of aperture blades while moving the filter substrate away from the aperture opening, thereby reducing the number of parts and improving shading, etc. The technology of the characteristics.

A first aspect of the present invention is an aperture device comprising: a pair of aperture blades that form a diaphragm opening in a state of being superposed on each other; a filter substrate having a visible light transmission region; and an aperture driving portion And moving the pair of aperture blades relatively to adjust the size of the aperture opening; and the filter driving unit moving forward and backward with respect to the optical path of the incident light passing through the aperture opening And the filter substrate further includes a light attenuating region that attenuates at least light passing through the visible light penetrating region among the light passing through the aperture of the aperture; the light attenuating region has a visible light transmitting region The small area is formed in the visible light transmission region, and is disposed concentrically with the aperture opening when the filter substrate is advanced to the optical path.

A second aspect of the invention is the aperture device of the first aspect, wherein the light attenuating region is formed in a circular shape.

A third aspect of the invention is the aperture device of the first aspect, wherein the light attenuating region is formed in a shape similar to an opening shape of the aperture opening.

A fourth aspect of the invention is the aperture device of the first aspect, the second aspect or the third aspect, wherein the visible light transmission region includes an infrared cut filter formed on a principal surface of at least one of the filter substrates The light attenuation region includes an ND filter layer formed on one of the main surfaces of the filter substrate or the other main surface or both main surfaces.

According to a fifth aspect of the present invention, in the fourth aspect, the infrared cut filter layer and the ND filter layer are formed in a laminated state on a common side of the filter substrate. On the surface.

According to a sixth aspect of the invention, there is provided a camera comprising: the aperture device described in any one of the first to fifth aspects; and the photoelectric conversion element which is incident light passing through the aperture opening Converted to an electrical signal.

A seventh aspect of the present invention provides an electronic apparatus comprising: the camera described in the sixth aspect; and an image processing unit that processes the image signal output from the camera.

According to the present invention, in the aperture device which can change the aperture opening by using a pair of aperture blades and simultaneously move the filter substrate relative to the aperture opening, the number of parts can be reduced and the characteristics such as light shielding can be improved at the same time.

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

Embodiments of the present invention will be described in the following order.

1. The composition of the camera

2. Composition of the aperture device

2-1. The overall composition of the aperture device

2-2. Part of the aperture device

3. Action of the aperture device

3-1. About the adjustment of the aperture opening

3-2. About the switching action of the photography mode

4. About the effect of the implementation

5. Modifications

<1. Composition of camera>

Fig. 1 is a view showing an example of a configuration of a camera to which the present invention is applied, (A) is an external view of the entire camera, and (B) is a schematic view of the inside of the lens barrel. The illustrated camera 100 is, for example, a surveillance camera that is installed on a ceiling portion (or a wall or the like) of a building for security purposes. The camera 100 includes a mounting base 101 and a camera body 102. The mounting base 101 is, for example, a structure that is fixed to a ceiling portion of a building by a fixing screw.

The camera body 102 includes a barrel portion 103 and an objective lens 104. An optical system including the objective lens 104 is assembled inside the barrel portion 103. The objective lens 104 is attached to the front end of the barrel portion 103. Further, in the camera body 102, the diaphragm device 1 and the imaging element 105 are incorporated as one functional portion of the optical system. The aperture device 1 will be described in detail later.

The imaging element 105 is an imaging element capable of color photography, and is configured by, for example, a CCD (Charge Coupled Device) imaging device, a CMOS (Complementary Metal Oxide Semiconductor) imaging device, or the like. The imaging element 105 has, for example, an imaging surface in which a plurality of (majority) pixels are arranged in a matrix. The imaging element 105 is incorporated as an example of a photoelectric conversion element that converts light incident on the imaging surface by the aperture opening of the aperture device 1 into an electrical signal.

Furthermore, the present invention is not limited to the camera 100 exemplified herein, and can be applied to a camera having another configuration of the diaphragm device 1. Further, as the configuration of the optical system, various types of lenses, the number of sheets, the arrangement, and the arrangement of the diaphragm device 1 can be variously changed.

<2. Composition of aperture device> [2-1. Composition of the entire aperture device]

Fig. 2 is an exploded perspective view showing an example of the configuration of the entire aperture device according to the embodiment of the present invention. The aperture device 1 shown in the drawings is mainly configured to include a diaphragm substrate 2, a pair of (two) aperture blades 3 and 4, a filter substrate 5, a blade cover 6, a diaphragm drive unit 7, and a filter drive unit. 8.

The diaphragm substrate 2 is a base for mounting the constituent members constituting each of the diaphragm devices 1. The pair of aperture blades 3, 4 are formed so as to overlap each other to form a diaphragm opening. The aperture opening is disposed on a light path of light incident on the camera to define the amount of light passing therethrough. That is, when the size of the aperture opening is increased, the amount of light passing through the optical path is relatively increased, and when the size of the aperture opening is decreased, the amount of light passing through the optical path is relatively reduced. The filter substrate 5 is an optical filter function for incident light. The blade cover 6 protects the pair of aperture blades 3, 4 from the outside.

The diaphragm driving unit 7 moves the pair of diaphragm blades 3 and 4 relatively to adjust the size of the diaphragm opening. The filter driving unit 8 moves the filter substrate 5 to switch the filter substrate 5 to a use state and a non-use state. The state in which the filter substrate 5 is used refers to a state in which the filter substrate 5 is advanced to the light path of the incident light. The non-use state of the filter substrate 5 is a state in which the filter substrate 5 is retracted (retracted) from the light path of the incident light.

[2-2. Part of the aperture device] (aperture substrate)

The diaphragm substrate 2 is formed of, for example, a resin, and is formed in a substantially rectangular shape in plan view. The aperture substrate 2 is formed with an opening 10 and a plurality of protrusions 11a, 11b, 11c, and 11d. The opening portion 10 is formed in a circular shape that is a perfect circle or a nearly circular shape. The plurality of protrusions 11a, 11b, 11c, and 11d are for guiding the movers of the pair of diaphragm blades 3, 4. The end portions of the respective projections 11a, 11b, 11c, and 11d are bent in an L shape toward the outer side of the diaphragm substrate 2, respectively.

(aperture blade)

The pair of aperture blades 3 and 4 are configured, for example, by using a carbon film to cover the surface of a plate-like material made of polyethylene terephthalate (PET). Each of the diaphragm blades 3 and 4 is formed in a thin plate shape as a whole. One aperture portion 15, three guide grooves 16a, 16b, 16c, and one engagement hole 17 are provided in one of the aperture blades 3.

The hole portion 15 has a planar shape in which a part of a circular shape that is a perfect circle or a nearly circular shape is enlarged to a substantially V shape. The three guide grooves 16a, 16b, and 16c are formed in parallel with each other along the longitudinal direction of the diaphragm blades 3. Among the three guide grooves 16a, 16b, and 16c, the two guide grooves 16b and 16c are formed on the same straight line. Further, the remaining one of the guide grooves 16a is formed on the opposite side of the two guide grooves 16b and 16c via the hole portion 15. The engagement holes 17 are formed on the extension lines of the two guide grooves 16b and 16c. Further, the engagement hole 17 is formed in a long hole shape in plan view along the short side direction of the diaphragm blade 3.

On the other hand, the other one of the aperture blades 4 is provided with one bay portion 18, three guide grooves 19a, 19b, and 19c, and one engagement hole 20. The bay portion 18 has a planar shape in which one of the semicircular (or elliptical) portions is enlarged to a substantially V shape. The three guide grooves 19a, 19b, and 19c are formed in parallel with each other along the longitudinal direction of the diaphragm blades 4. Among the three guide grooves 19a, 19b, and 19c, the two guide grooves 19a and 19b are formed on the same straight line. Further, the remaining one of the guide grooves 19c is formed on the opposite side of the two guide grooves 19a and 19b via the bay portion 18. The engagement hole 20 is formed on an extension line of the two guide grooves 19a and 19b. Further, the engagement hole 20 is formed in a long hole shape in plan view along the short side direction of the diaphragm blade 4.

(filter substrate)

The filter substrate 5 is disposed in a state of being inserted between the pair of diaphragm blades 3 and 4 (gap portion). The filter substrate 5 is configured, for example, by using a circular glass substrate having light transmissivity. When the front surface and the back surface of the filter substrate 5 are each defined as the main surface of the filter substrate 5, a filter layer is formed on at least one of the main surfaces of the filter substrate 5. The configuration of the filter substrate 5 including the filter layer will be described in detail later.

The filter substrate 5 is attached to the frame member 23. The frame member 23 has a circular opening (not shown) corresponding to the outer shape of the filter substrate 5. The filter substrate 5 and the frame member 23 are integrally formed to constitute one filter unit 24. Specifically, the filter substrate 5 and the frame member 23 are integrally formed by, for example, a fixing means such as the following.

The frame member 23 is made of, for example, a resin. An arm portion 25 is integrally formed on the frame member 23 . The arm portion 25 is bent in a substantially L shape, and a circular hole 26 is formed in a curved portion thereof. Further, a long hole 27 is formed on the front end side of the arm portion 25. Further, two projecting portions 28 and 29 are integrally formed on the frame member 23. The respective projections 28, 29 serve primarily two purposes. One object is to stabilize the movement of the pair of diaphragm blades 3, 4 by interaction with the protruding portion of the arm portion 25. Another object is to secure the subsequent portion when the filter substrate 5 is fixed to the frame member 23 by means of an adhesive.

(blade cover)

The blade cover 6 is formed into a plate shape using, for example, a metal such as aluminum. Similarly to the above-described diaphragm substrate 2, the blade cover 6 is formed in a substantially rectangular shape in plan view. The blade cover 6 is provided with one opening 30 and two clearance grooves 31a and 31b. The opening portion 30 is formed in a circular shape that is a perfect circle or a nearly circular shape. The opening 30 is disposed so as to overlap the aperture opening formed by the pair of diaphragm blades 3 and 4. The clearance groove portions 31a and 31b are formed in pairs in one direction and the other in the short side direction of the blade cover 6. Each of the clearance groove portions 31a and 31b is formed in a substantially arc shape in plan view in a state of penetrating the thickness direction of the blade cover 6. Further, an arm portion 32 is integrally formed on the blade cover 6. The arm portion 32 is formed in a state of protruding toward one of the short sides of the blade cover 6. A long hole 33 is formed in the arm portion 32. Further, the blade cover 6 is formed with a pair of hole portions 36a and 36b and a pair of notch portions 37a and 37b.

(aperture drive unit)

The diaphragm drive unit 7 transmits a pair of diaphragm blades 3 and 4 to a pair of diaphragm blades 3 and 4 via a driving force transmission mechanism (such as a gear mechanism) (not shown) via a driving force of a motor serving as a driving source. Perform relative moves. The driving source thereof is, for example, a moving magnet motor. The diaphragm driving unit 7 has a pair of driving pins 34a and 34b. The pair of drive pins 34a and 34b are disposed on the same circumference at positions shifted by about 180 degrees. The pair of drive pins 34a, 34b are equally moved in the same direction on the same circumference by the drive of the drive source. Further, the diaphragm driving unit 7 and the pair of diaphragm blades 3 and 4 are engaged with the diaphragm blades 4 by engaging one of the driving pins 34b with the engaging holes 17 of the diaphragm blades 3, respectively. The engagement holes 20 are coupled to each other.

(filter drive unit)

The filter driving unit 8 transmits the driving force of the motor serving as the driving source to the filter unit 24 via a driving force transmission mechanism (such as a gear mechanism) (not shown), so that the filter substrate 5 is included. The filter unit 24 performs the movement. Its drive source, for example, uses a stepper motor. The filter unit 24 is rotatably supported around the support shaft 35 by inserting the circular hole 26 of the arm portion 25 into the support shaft 35. The support shaft 35 is, for example, integrally formed on the diaphragm substrate 2. The filter driving unit 8 and the filter unit 24 are connected to each other by, for example, providing a driving pin to the filter driving unit 8 and engaging the driving pin with the long hole 27 of the arm portion 25.

(assembly)

Next, a description will be given of a procedure for assembling the diaphragm device 1 using the respective components described above. Here, as an example, the pair of diaphragm blades 3 and 4, the filter unit 24, and the blade cover 6 are attached to the diaphragm substrate 2, and the diaphragm driving unit 7 and the filter driving unit 8 are attached. Mounted on the aperture substrate 2.

First, the diaphragm blades 3 are attached to the aperture substrate 2. At this time, the projections 11a, 11c, and 11d of the diaphragm substrate 2 are fitted into the guide grooves 16a, 16b, and 16c of the diaphragm blade 3, respectively. Further, one of the drive driving pins 34b of the diaphragm driving unit 7 is fitted into the engaging hole 17 of the diaphragm blade 3.

Next, the filter unit 24 is attached to the aperture substrate 2. In this case, the circular hole 26 of the arm portion 25 is fitted into the support shaft 35 of the diaphragm substrate 2, and a driving pin (not shown) of the filter driving portion 8 is fitted into the long hole 27 of the arm portion 25.

Next, the diaphragm blades 4 are attached to the aperture substrate 2. At this time, the projections 11a, 11b, and 11c of the diaphragm substrate 2 are fitted into the guide grooves 19a, 19b, and 19c of the diaphragm blade 4, respectively. Further, the other drive pin 34a of the diaphragm drive unit 7 is fitted into the engagement hole 20 of the diaphragm blade 4.

Next, the blade cover 6 is attached to the aperture substrate 2. At this time, the support shaft 35 of the diaphragm substrate 2 is fitted into the long hole 33 of the arm portion 32 of the blade cover 6. The fixing of the substrate cover 6 with respect to the diaphragm substrate 2 is performed, for example, by fitting or the like.

When the blade cover 6 is attached to the diaphragm substrate 2 in this manner, the interference between the two is avoided in the following manner. First, the positional interference of the drive pin 34b and the blade cover 6 which are protruded by the engagement hole 17 of the aperture blade 3 is prevented by the clearance groove portion 31b. Similarly, the positional interference of the other driving pin 34a of the diaphragm driving portion 7 which protrudes through the engaging hole 20 of the diaphragm blade 4 and the blade cover 6 is avoided by the clearance groove portion 31a. Further, the interference between the projections 11a and 11c of the diaphragm substrate 2 and the position of the blade cover 6 is avoided by the pair of holes 36a and 36b, and the positions of the projections 11b and 11d of the aperture substrate 2 and the blade cover 6 are The interference is avoided by the pair of notch portions 37a, 37b.

When the diaphragm device 1 is assembled as described above, the pair of diaphragm blades 3 and 4 are movably supported by sliding (sliding) by the four projections 11a, 11b, 11c, and 11d on the diaphragm substrate 2. Further, the filter unit 24 is movably supported in a direction in which the support shaft 35 is rotated about the center. Further, the opening portion 10 of the diaphragm substrate 2 and the opening portion 30 of the blade cover 6 are disposed in a state in which the thickness of the diaphragm substrate 2 is opposed to each other (in a state of being superposed), and the hole portion 15 of the diaphragm blade 3 is The bay portions 18 of the diaphragm blades 4 are disposed on opposite sides thereof in a state of being superposed on each other.

The diameter of the substantially circular shape of the hole portion 15 of the diaphragm blade 3 is set to be substantially the same as the diameter of the semicircular portion of the bay portion 18 of the predetermined diaphragm blade 4. Further, in a state where the two aperture blades 3, 4 are superposed on each other, a portion of the aperture portion 15 of the aperture blade 3 and the bay portion 18 of the aperture blade 4 are overlapped to form a diaphragm opening. Therefore, the aperture opening formed by the pair of aperture blades 3 and 4 is enlarged or reduced in the region where the opening portion 10 of the aperture substrate 2 and the opening portion 30 of the blade cover 6 are opposed to each other. However, there is also a case where the aperture opening is completely closed depending on the positions of the aperture blades 3, 4.

(Detailed description of the filter substrate)

Here, the configuration of the above-described filter substrate 5 will be described in detail.

Fig. 3 is a plan view showing the filter unit enlarged. 4 is a cross-sectional view of the filter substrate. Further, the circular dotted line shown in Fig. 3 indicates an opening formed in the frame member.

The filter substrate 5 is formed, for example, on a susceptor to constitute a glass substrate 40. As an example of the glass substrate 40, ultraviolet (UV; UltraViolet) cut glass is used. An infrared cut filter layer 41 and an ND (Neutral Density) filter layer 42 are formed on one of the main surfaces of the filter substrate 5. The infrared cut filter layer 41 is a filter layer that cuts off the light of the infrared region (including the near-infrared region). The infrared cut filter layer 41 is formed on one main surface of the glass substrate 40 so as to cover the entire surface of the main surface, covering the entire area of the main surface. Further, the infrared cut filter layer 41 is formed on the glass substrate 40 with the same thickness. Thus, the infrared cut filter layer 41 is formed on the glass substrate 40, and the region in which the infrared cut filter layer 41 is formed is a region that shields the light in the infrared region. Further, since the glass substrate 40 is formed of ultraviolet cut glass, the entire area is a region that shields light in the ultraviolet region. Therefore, the region in which the infrared cut filter layer 41 of the glass substrate 40 is formed is a region through which visible light can be transmitted, that is, a visible light penetrating region, in a state where light in the infrared region and the ultraviolet region is removed. However, the visible light penetrating region may not be a region that strictly penetrates only visible light. Specifically, in the light penetrating the visible light penetrating region, in addition to the visible light, light belonging to a part of the ultraviolet region or light belonging to a part of the infrared region may be included.

On the other hand, the ND filter layer 42 is a filter layer that attenuates light incident on the ND filter layer 42. Further, the ND filter layer 42 is a filter layer having a lower wavelength dependency than a region in which the infrared cut filter layer 41 is formed (hereinafter also referred to as a "visible light transmission region"). Therefore, the region where the ND filter layer 42 is formed is a region that attenuates at least light that can penetrate the visible light penetrating region, that is, a light attenuating region, in the light passing through the aperture opening. For example, as long as only visible light is light that can penetrate the visible light transmission region, the region where the visible light is attenuated is the light attenuation region. In this case, the transmittance of visible light of the ND filter layer 42 depends on the characteristics of the image pickup element incorporated in the camera, and is preferably set to about 6%. However, the ND filter layer 42 has a characteristic of attenuating light of each of the ultraviolet region, the visible region, and the infrared region at a uniform transmittance. Therefore, the light that can be attenuated by the ND filter layer 42 is not limited to visible light.

In the main surface of the filter substrate 5, as an area ratio of the visible light transmitting region and the light attenuating region, it is preferable to make the aperture opening into a fully open state and effectively function as a visible light transmitting region. When it is set to 100%, it is set so that the ratio of the area of the light-diffusion area with respect to this is 4 to 33%. The reason why the area ratio of the light-attenuating region is so widely defined is that the area ratio of the light-attenuating region is changed according to the aperture opening diameter when the aperture opening is fully opened, and the area of the visible light-transmitting region when the aperture opening is fully opened. . Specifically, as the aperture opening diameter increases with full opening, the area ratio of the appropriate light attenuation region becomes smaller, and conversely, as the aperture opening diameter becomes smaller with full opening, the area ratio of the appropriate light attenuation region becomes smaller. Big.

The ND filter layer 42 is formed on the infrared cut filter layer 41 on the main surface side of one of the glass substrates 40 in a laminated state. Further, the ND filter layer 42 is formed on the infrared cut filter layer 41 with the same thickness. The ND filter layer 42 is formed in a circular shape at a central portion thereof with respect to a region where the infrared cut filter layer 41 is formed when the filter substrate 5 is viewed in a plan view. That is, the filter substrate 5 is an eyeball type filter structure. Specifically, the region in which the infrared cut filter layer 41 is formed is a scleral portion, and the region in which the ND filter layer 42 is formed on the inner side is an eyeball type having an iris portion.

As can be seen from the figure, the ND filter layer 42 is formed on the central portion of the filter substrate 5 in accordance with a region smaller than the region in which the infrared cut filter layer 41 is formed. Further, the region in which the infrared cut filter layer 41 is formed as described above is a visible light penetrating region. Therefore, the ND filter layer 42 is formed in the visible light penetrating region.

As shown in Fig. 5, the outer dimensions of the ND filter layer 42 (diameter in the case of the figure) are set according to the opening size when the aperture opening 43 of the pair of aperture blades 3, 4 is formed into a small aperture. In the present specification, the state of the small aperture means that the opening area of the actual aperture opening 43 is 1/3 or less with respect to the opening area when the aperture opening 43 is fully opened. In the state of the small aperture, the aperture opening 43 is formed by forming a V-shaped notch portion in one of the hole portions 15 of the aperture blade 3 and forming a V-shaped notch portion in a portion of the bay portion 18 of the aperture blade 4. The shape of the opening becomes a quadrangle (diamond).

As a specific manufacturing method for forming the infrared cut filter layer 41 or the ND filter layer 42 on the glass substrate 40, for example, a well-known film forming method such as a vacuum deposition method, a sputtering method, or a coating method can be employed. Further, after the infrared cut filter layer 41 is formed on the glass substrate 40, when the ND filter layer 42 is to be formed, it is necessary to restrict the formation region of the ND filter layer 42. In this case, only the portion where the ND filter layer 42 is to be formed may be opened to the glass substrate 40 on which the infrared cut filter layer 41 has been formed, and the ND filter may be formed in a state where the masking process is performed. Layer 42.

Further, when the filter substrate 5 is advanced to the light path of the incident light as described above, the center of the filter substrate 5 is aligned with the center position of the aperture opening in which the pair of diaphragm blades 3 and 4 are formed. Therefore, in the use state of the filter substrate 5, the region (light attenuating region) in which the ND filter layer 42 is formed is arranged concentrically with the aperture opening. Therefore, if the aperture opening is made into a small aperture state, the surface contact ratio of the ND filter layer 42 to the aperture area of the aperture opening becomes extremely high. In particular, when photographing is performed in a bright environment (outdoor of a sunny day, etc.), since the aperture opening is reduced, the ND filter layer 42 is disposed so as to cover the entire area of the aperture opening.

<3. Action of aperture device>

Next, the operation of the aperture device 1 according to the embodiment of the present invention will be described.

[3-1. About the adjustment of the aperture opening]

First, the basic operation principle of the diaphragm device 1 will be described.

When the aperture opening formed by the pair of aperture blades 3, 4 is adjusted, the diaphragm driving portion 7 is driven. As a result, the driving force of the diaphragm driving unit 7 causes the pair of diaphragm blades 3 and 4 to move in a relatively close or distant direction.

When the pair of diaphragm blades 3, 4 are relatively moved as described above, the size of the diaphragm opening 43 changes depending on the moving direction and the amount of movement of the diaphragm opening 43. Specifically, when the pair of aperture blades 3, 4 are moved toward each other (the direction of the arrow in the solid line of FIG. 5), the aperture opening 43 will become larger as the pair of aperture blades 3, 4 are moved away from each other. When the direction (the direction of the arrow of the broken line in Fig. 5) moves, the aperture opening 43 will become smaller. Further, in a state where the pair of aperture blades 3, 4 are closest to each other, the aperture opening 43 will be maximized (fully open state), and in a state where the pair of aperture blades 3, 4 are farthest apart, the aperture opening 43 will be minimized. (A state of complete shutdown or a state of near complete shutdown).

Fig. 6 is a view showing a state in which the aperture opening is opened (fully opened). When the photographing is performed in the monochrome photographing mode, the filter substrate 5 is in a state of being retracted from the aperture opening 43. Fig. 7 is a view showing a state in which the aperture opening 43 is made into a small aperture. When the aperture opening 43 is made into a small aperture, as shown in FIG. 5 described above, the aperture opening 43 is formed in a substantially rhombic shape at a portion where the aperture portion 15 of the pair of aperture blades 3 and 4 and the bay portion 18 are overlapped. Further, the ND filter layer 42 is disposed in a state in which the aperture opening 43 is completely covered (covered). However, the case where the ND filter layer 42 is disposed in the aperture opening 43 is only to advance the filter substrate 5 to the light path of the incident light.

[3-2. About the switching of the shooting mode]

As a form of switching between the shooting modes, there are cases where the color shooting mode is switched to the monochrome shooting mode, and the case where the monochrome shooting mode is switched to the color shooting mode. However, in either case, the filter driving unit 8 is driven when the shooting mode is switched. The following describes the situation.

First, when the photographing mode is switched from the color photographing mode to the monochrome photographing mode, receiving the driving force driven by the filter driving unit 8 causes the filter unit 24 to move around the support shaft 35 as a center. . Thereby, the optical path of the light incident on the filter substrate 5 from the aperture opening 43 is retracted to the offset position. Therefore, when photographing is performed in the monochrome photographing mode, the light incident through the aperture opening 43 does not reach the imaging element (not shown) via the filter substrate 5. Therefore, in addition to the decrease in the amount of light caused by the infrared cut filter layer 41, the amount of light caused by the ND filter layer 42 does not decrease. Therefore, it becomes a photographer who is suitable for nighttime and the like which obtains the necessary resolution with a small amount of light.

On the other hand, when the photographing mode is switched from the monochrome photographing mode to the color photographing mode, the filter driving unit 8 is driven to reverse the operation direction of the above-described case. As a result, the driving force received by the filter driving unit 8 causes the filter unit 24 to move so as to rotate the support shaft 35 as a center. Thereby, the filter substrate 5 is advanced to a position on the light path of the light incident through the aperture opening 43. Therefore, when photographing is performed in the color photographing mode, the light incident through the aperture opening 43 is passed through the filter substrate 5 to the imaging element (not shown).

Here, the color photography mode is suitable for bright environments such as daylight. Further, in this imaging environment, the light amount adjustment by the diaphragm device 1 is performed in a state where the aperture of the pixel of the imaging element is not saturated as described above. Therefore, the entire or most of the aperture opening 43 is covered by the filter function layer including the infrared cut filter layer 41 and the ND filter layer 42. Thereby, even if the ND filters are separately attached to the pair of diaphragm blades as in the prior art, the filtering functions of the infrared cut filter layer 41 and the ND filter layer 42 also function together. Therefore, it becomes a photographer suitable for a bright day or the like in a photographic environment.

Moreover, even in the case of daylight, such as a bad weather, or due to the location of a camera, it is possible to perform photography in a dim environment. In this case, in order to secure the required amount of light, the filter substrate 5 is maintained in the forward state, and the aperture opening 43 is opened larger than in the state of the small aperture. Therefore, the aperture opening 43 is opened larger than the formation area of the ND filter layer 42. On the other hand, since the infrared cut filter layer 41 is formed on the entire surface on one side of the filter substrate 5, even if the aperture opening 43 is opened to the fully open state, the infrared cut filter layer 41 is always covered by the aperture. The opening 43 is configured in a manner. Therefore, when photographing in the color photographing mode, even if the aperture opening 43 is made larger in order to secure the amount of light or the like, there is no possibility of color deviation due to the incident of the infrared light.

<4. Effect on the embodiment>

In the aperture device according to the embodiment of the present invention, the camera having the above-described camera can reduce the number of components and the shading at the same time, in addition to the photographer who is suitable for nighttime and the like which can obtain a desired resolution with a small amount of light. And so on. The reasons are stated below.

First, as the configuration of the aperture device 1, the infrared cut filter layer 41 and the ND filter layer 42 are formed on the filter substrate 5. Therefore, the number of parts can be reduced as compared with the case where the conventional ND filter is attached to the diaphragm blade as a separate component.

Further, as the configuration of the aperture device 1, when the filter substrate 5 is advanced to the light path of the light incident through the aperture opening 43, the ND filter layer 42 is configured to be concentric with the aperture opening 43. . Therefore, when the aperture opening 43 is made into a small aperture and the imaging is performed, not only the ND filter layer 42 functions effectively, but also the entire aperture opening 43 is covered by the ND filter layer 42. Therefore, even in the state of a small aperture, the image as a whole becomes uniform brightness. Therefore, characteristics such as shading are improved.

Further, even when the aperture opening 43 is opened larger than the state of the small aperture, the characteristics such as light shielding can be improved. In other words, the diaphragm opening 43 is in an operating state that is larger than the state of the small diaphragm, and is applied to, for example, a dim environment of daylight. Therefore, the amount of light incident on the camera will become relatively small compared to the bright environment of daylight. Therefore, even if the aperture opening 43 is opened larger than the formation region of the ND filter layer 42, the difference in brightness between the ND filter layer 42 and the ND filter layer 42 will become Significantly smaller. Further, even if the size of the aperture opening 43 is changed by the relative movement of the pair of aperture blades 3, 4, the position of the ND filter layer 42 does not change, so that the center position of the luminance does not shift. Therefore, compared with the configuration in which the ND filter is separately attached to the pair of aperture blades as in the conventional aperture device, characteristics such as light shielding are improved.

Further, in the case of the conventional aperture device, when the aperture opening is gradually opened from the state of the small aperture, the light passing through the aperture opening is divided into light passing through the overlapping portions of the two ND filters, passing either of them. The light of the ND filter and the light that does not pass through part of the ND filter. On the other hand, in the case of the aperture device of the present embodiment, the light passing through the aperture opening 43 is limited to the light passing through the portion of the ND filter layer 42 (the central portion of the aperture opening 43), and passing through the ND filter. The light of the portion other than the layer 42 (the surrounding portion of the aperture opening 43). Therefore, unevenness in the distribution of light and dark can be suppressed. Therefore, the effect of improving characteristics such as shading is more remarkable.

Further, as the number of parts described above is reduced, the following effects can be obtained. That is, in the case of manufacturing the aperture device 1, there is no need to install the ND filter on the diaphragm blade. Further, in the case where the ND filter is attached to the diaphragm blade by means of an adhesive, it is necessary to add the thickness of the adhesive to the thickness of the ND filter (for example, about 0.1 mm) to set a pair of aperture blades. The gap that moves relatively. On the other hand, when the ND filter layer 42 is formed on the filter substrate 5, the thickness is only about several μm to several tens of μm. Therefore, the thickness of the aperture device 1 can be reduced. Further, in the operation of the aperture device, since the aperture blade is frequently moved in the reverse direction, the ND filter is attached to the aperture blade by the next step or the like, and the ND is caused by the vibration accompanying the movement of the aperture blade. The filter has fallen off. On the other hand, when the ND filter layer 42 is formed on the filter substrate 5, such a defect does not occur. Therefore, it is possible to realize an aperture device which is excellent in reliability of operation under long-term use.

Further, as a configuration of the filter substrate 5, the light attenuating region including the ND filter layer 42 is formed into a circular shape. Therefore, even if the aperture shape of the aperture opening 43 is a small aperture, for example, a polygonal shape or an elliptical shape, if a circle having a diameter smaller than or equal to the diameter of the circle is formed to form a light attenuation region, the difference in the shape of the opening may be made. Features such as shading are improved. Therefore, it is excellent in versatility.

Further, particularly as a preferred example, a configuration in which a light attenuating region is formed in a shape similar to the shape of the opening of the aperture opening 43 may be employed. For example, when the pair of diaphragm blades 3 and 4 are superimposed, the shape of the aperture opening 43 formed by the hole portion 15 and the bay portion 18 is quadrangular (diamond) due to the existence of the respective V-shaped notch portions. In the case, the light attenuating region is formed into a similar shape.

According to this configuration, when the aperture opening 43 is used as the small aperture for color photography, the state in which the aperture opening 43 is covered by the ND filter layer 42 is maintained until the aperture size of the aperture opening 43 and the ND filter layer 42 are maintained. The shape and shape outside the formation area are the same. Therefore, the formation region of the ND filter layer 42 can be utilized to the utmost and without waste. Further, along with this, the formation region of the ND filter layer 42 can be minimized. Therefore, the reduction in the amount of light when the aperture opening 43 is opened in the color photographing mode can be suppressed as much as possible.

Further, when the aperture opening 43 is opened larger than the state of the small aperture, the region where the ND filter layer 42 is not formed (hereinafter referred to as "non-formation region") covers the entire outer edge portion of the aperture opening 43. It is evenly distributed around. Therefore, in the opening region of the aperture opening 43, in the formation region of the ND filter layer 42 at the central portion thereof, the image system is relatively dark, and in the non-formation region of the ND filter layer 42, The image is relatively bright. On the other hand, the lens for photography is generally brighter at the center portion and darker toward the edge portion. Therefore, the brightness of the image can be made uniform by the comparison.

Further, in the configuration of the filter substrate 5, the infrared cut filter layer 41 and the ND filter layer 42 are formed in a laminated state on the common surface of the glass substrate 40. Therefore, when the filter substrate 5 is manufactured, the infrared cut filter layer 41 and the ND filter layer 42 can be sequentially formed (formed) without causing the glass substrate 40 to be reversed in the front and back directions.

<5. Modifications>

The technical scope of the present invention is not limited to the above-described embodiments, and various modifications and improvements may be added to the extent that the specific effects obtained by the constituent elements of the invention or a combination thereof can be guided.

For example, the ND filter layer 42 may be formed not on one main surface of the glass substrate 40 but on the main surface opposite to the main surface on which the infrared cut filter layer 41 is formed. Further, the infrared cut filter layer 41 and the ND filter layer 42 may be formed on the main surfaces of both of the glass substrates 40, respectively. Further, the planar shape of the light attenuating region including the ND filter layer 42 is not limited to the above-described circular shape, and may be, for example, a triangle belonging to a polygon, a square, a pentagon, or a hexagon, (hereinafter, omitted) It can also be other shapes, such as star, petal, cross, cloud, and half moon.

Further, the order of laminating the infrared cut filter layer 41 and the ND filter layer 42 on the glass substrate 40 may be reversed to the above embodiment, that is, over the ND filter layer 42 to cover the ND. The state of the filter layer 42 forms the infrared cut filter layer 41.

Further, the infrared cut filter layer 41 and the ND filter layer 42 may be formed on the respective glass substrates, and the filter substrate may be formed by integrating the glass substrates, for example, or the like. .

Further, it is also possible to perform a movement operation of the filter substrate 5 by switching the photographing mode by a sliding operation of, for example, a linear motion, instead of the rotation operation centering on the support shaft 35 as in the above embodiment. . In the case of adopting such a configuration, for example, the main surface region of the rectangular substrate may be divided into two regions along the longitudinal direction of the substrate, and the infrared cut filter layer may be formed only in one region, and in the center thereof. Part of the formation of the ND filter layer.

Further, the configuration of the filter substrate 5 having the infrared cutoff function is not limited to the configuration in which the infrared cut filter layer 41 is formed on the glass substrate 40 as in the above embodiment, and for example, the glass substrate 40 itself may be used. The function of having a function of cutting off infrared rays is a configuration using a glass substrate 40 composed of infrared cut glass.

Further, the configuration of the filter substrate 5 having the ultraviolet cutoff function is not limited to the glass substrate 40 composed of the ultraviolet cut glass as in the above embodiment, and the ultraviolet cut filter may be formed on the main surface of the glass substrate. The composition of the slice.

Further, the ND filter layer 42 may be formed on the film substrate, and the film substrate may be attached to the glass substrate 40.

Further, in the configuration of the aperture device of the present invention, regarding the "visible light transmission region", the visible light transmission region is a region through which visible light is transmitted, and in detail, visible light is removed in a state where light of a predetermined wavelength region is removed. The region of penetration, more specifically, the region through which visible light is transmitted in a state where light which is not required for photographing of a camera in visible light is removed. In this case, the light that is not required for the photographing of the camera refers to light of at least one of "light having a wavelength longer than visible light" and "light having a shorter wavelength than visible light". More specifically, at least one of infrared light (including near-infrared light) and ultraviolet light (including near-ultraviolet light) corresponds to "light that is not required for camera photography".

Therefore, in addition to the filtering function of both the infrared cut filter and the ultraviolet cut filter, the "visible light transmission region" of the filter substrate 5 may have only infrared cut filter. The case of the function of the film, or the case of having only the function of the ultraviolet cut filter. However, in terms of preventing color deviation of the image, it is preferable to have an area of the filtering function of both the infrared cut filter and the ultraviolet cut filter. Further, in the visible light transmission region, it is not necessary to make the entire region on the main surface of the glass substrate 40 a visible light transmission region, and it is only necessary to secure the visible light transmission region so as to be larger than the light attenuation region.

Further, the present invention is not limited to a diaphragm device or a camera using an aperture device, and can be applied to an electronic device (for example, a security device or the like) including the camera. The electronic device is configured to include a camera according to an embodiment of the present invention and a video processing unit that processes video signals output from the camera.

1,200. . . Aperture device

2, 201. . . Aperture substrate

3, 4, 202, 203. . . Aperture blade

5, 204. . . Filter substrate

6. . . Blade cover

7. . . Aperture drive unit

8. . . Filter drive unit

10, 30. . . Opening

11a, 11b, 11c, 11d. . . Protrusion

15, 26, 210, 36a, 36b. . . Hole

16a, 16b, 16c, 19a, 19b, 19c. . . Guide slot

17,20. . . Engagement hole

18, 211. . . Bay Department

23,214. . . Frame member

24,215. . . Filter unit

25, 32. . . Arm

27, 33. . . Long hole

28, 29. . . Protruding

31a, 31b. . . Clearance

34a, 34b. . . Drive pin

35. . . Support shaft

37a, 37b. . . Notch

40. . . glass substrate

41‧‧‧Infrared cut filter layer

42‧‧‧ND filter layer

43,216‧‧‧ aperture opening

100‧‧‧ camera

101‧‧‧Installation base

102‧‧‧ camera body

103‧‧‧Mirror tube

104‧‧‧ Objective lens

105‧‧‧Photographic components

205‧‧‧ blade cover

206‧‧‧Aperture drive department

207‧‧‧Filter Driver

208, 209‧‧ ND filters

210‧‧‧ Hole Department

212‧‧‧ glass substrate

213‧‧‧Filter layer

Fig. 1 is a view showing an example of a configuration of a camera to which the present invention is applied, (A) is an external view of the entire camera, and (B) is a schematic view of the inside of the lens barrel.

Fig. 2 is an exploded perspective view showing an example of the configuration of the entire aperture device according to the embodiment of the present invention.

Fig. 3 is a plan view showing an enlarged view of the filter unit of the embodiment.

4 is a cross-sectional view of the filter substrate shown in FIG. 3.

Fig. 5 is a view showing a state in which a pair of diaphragm blades are superposed.

Fig. 6 is a view showing a state in which the aperture opening is opened (fully opened).

Fig. 7 is a view showing a state in which the aperture opening 43 is made into a small aperture.

Fig. 8 is an exploded perspective view showing an example of a conventional aperture device.

Fig. 9 is a plan view showing an enlarged view of a conventional filter unit.

Figure 10 is a cross-sectional view showing the filter substrate shown in Figure 9.

Fig. 11 is an exploded perspective view showing a state in which an ND filter is mounted on a diaphragm blade in a conventional aperture device.

Fig. 12 is a view showing a state in which a pair of blade substrates are superposed.

Fig. 13 is a view showing a state in which the aperture opening is opened (fully opened).

Fig. 14 is a view showing a state in which the aperture opening is made into a small aperture.

1. . . Aperture device

2. . . Aperture substrate

3, 4. . . Aperture blade

5. . . Filter substrate

6. . . Blade cover

7. . . Aperture drive unit

8. . . Filter drive unit

10, 30. . . Opening

11a, 11b, 11c, 11d. . . Protrusion

15, 26, 36a, 36b. . . Hole

16a, 16b, 16c, 19a, 19b, 19c. . . Guide slot

17,20. . . Engagement hole

18. . . Bay Department

twenty three. . . Frame member

twenty four. . . Filter unit

25, 32. . . Arm

27, 33. . . Long hole

28, 29. . . Protruding

31a, 31b. . . Clearance

34a, 34b. . . Drive pin

35. . . Support shaft

37a, 37b. . . Notch

42. . . ND filter layer

Claims (11)

An aperture device comprising: a pair of aperture blades that form a diaphragm opening in a state of being overlapped with each other; a filter substrate having a visible light transmission region; and a diaphragm driving portion that couples the pair The aperture blade is relatively moved to adjust the size of the aperture opening; and the filter driving portion moves forward and backward with respect to the optical path of the incident light passing through the aperture opening; and the filter substrate Further, there is provided: a light attenuating region which is a light attenuating region which can attenuate light passing through the visible light penetrating region among the light passing through the aperture of the aperture; the light attenuating region penetrates through the visible light The small area is formed in the visible light transmissive area, and is disposed to be concentric with the aperture opening when the filter substrate is advanced to the optical path. The aperture device of claim 1, wherein the light attenuating region is formed in a circular shape. The aperture device of claim 1, wherein the light attenuating region is formed in a shape similar to an opening shape of the aperture opening. The aperture device of claim 1, wherein the visible light transmission region includes an infrared cut filter layer formed on a principal surface of at least one of the filter substrates. The light attenuating region includes an ND filter layer formed on one of the main surfaces of the filter substrate or the other main surface or both main surfaces. The aperture device of claim 4, wherein the infrared cut filter layer and the ND filter layer are formed in a laminated state on a common surface of the filter substrate. The aperture device according to any one of claims 1 to 3, wherein the filter substrate is formed of an ultraviolet cut glass or an ultraviolet cut filter layer formed on a main surface of the glass substrate. The aperture device of claim 4, wherein the ND filter layer is formed on the infrared cut filter layer with the same thickness. The aperture device of claim 7, wherein the area of the light attenuating area is relative to the above when the visible light penetration area that effectively functions when the aperture opening is fully opened is 100% The area of the visible light penetration zone is 4 to 33%. The aperture device of claim 7, wherein the ND filter layer has a visible light transmittance of 6%. A photographic apparatus comprising: the aperture device according to any one of claims 1 to 5; and a photoelectric conversion element that converts incident light passing through the aperture opening into an electrical signal. An electronic machine characterized by having: The camera of claim 10; and the image processing unit for processing the image signal output from the camera.