JP2009116174A - Ghost reducing device and electronic camera provided therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce harmful light which is incident on an optical system and adversely affects an image formed by the optical system as stray light by a simple and compact structure. <P>SOLUTION: A variable opening light-shielding part 100 changing at least one of the dimension and shape of an opening for regulating a luminous flux traveling backward within an optical system is provided in the optical system. The variable opening light-shielding part 100 has an EC element composed of a plurality of segments 108a-108d, and independently controls the light transmittances of the plurality of segments, and the opening shape is formed by one or more segments set to have lower light transmittances. When the variable opening light-shielding part 100 is embedded in a variable focus optical system, the opening shape can be changed according to the magnification change operation of the variable focus optical system. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a ghost reduction device for reducing harmful light incident on an optical system or harmful light generated in the optical system, and an electronic camera equipped with the ghost reduction device.

  Light incident on an optical system such as a photographic lens is reflected by a lens holding member such as a lens surface, a lens edge, or a lens frame, and becomes stray light. Such light is called harmful light and affects the image formed by the optical system. This harmful light is desired to be removed because it causes an undesired ghost image in the screen and reduces the contrast of the subject image.

Patent Document 1 discloses a technique for effectively suppressing the generation of a ghost image. In Patent Document 1, a flare cutter is disposed immediately after the first lens group in the zoom lens. The flare cutter has an aperture diameter variable using an iris diaphragm mechanism. Further, the flare cutter is configured to be movable in the optical axis direction with respect to the movable lens group. Thereby, in patent document 1, generation | occurrence | production of a ghost image is suppressed effectively according to a zoom position.
JP 2000-9963 A

  However, in order to mechanically control both the aperture diameter of the ghost reducing member and the position in the optical axis direction in accordance with the change in the zoom position, the zoom lens drive mechanism must be complicated and enlarged.

  An object of the present invention is to enable effective suppression of harmful light that causes ghosting without complicating and increasing the size of the entire optical system such as a zoom lens.

  The present invention is applied to a ghost reduction apparatus for reducing harmful light. The ghost reduction device has a variable aperture light-shielding portion capable of changing at least one of the size and shape of an aperture for restricting a light beam traveling backward in the optical system. The variable aperture light shielding unit includes an EC element including a plurality of segments, and is configured to be able to independently control the light transmittance of the plurality of segments. And the problem mentioned above is solved by forming the dimension and shape of the opening by one or a plurality of segments set in a higher light transmittance state among the plurality of segments.

  In the present invention, the variable aperture light shielding part has an EC element composed of a plurality of segments. This variable aperture light-shielding portion is an aperture for restricting the light beam traveling backward in the optical system, and can change at least one of its size and shape. Further, the light transmittance of the plurality of segments is configured to be independently controllable. The size and shape of the opening are formed by one or a plurality of segments set to a higher light transmittance among the plurality of segments. Thereby, in this invention, the complicated mechanism for changing the dimension and shape of opening is not required. Further, in the present invention, even when the opening is set to be large, a space for retracting the light shielding member out of the optical path becomes unnecessary. Therefore, according to the present invention, it is possible to effectively suppress the generation of a ghost image with a simple and small configuration.

  FIG. 1A is a diagram illustrating a schematic configuration of the variable aperture light shielding unit 100. FIG. 1A shows an external perspective view of the variable aperture light shielding unit 100, and FIG. 1A shows a front view thereof. Here, the variable aperture light shielding unit 100 is an element constituting the ghost reduction device according to the embodiment of the present invention. The variable aperture light shielding unit 100 includes an electrochromic element (EC element) as a light shielding member. In the electrochromic element, the light shielding state and the light transmitting state can be electrically controlled. Therefore, the variable aperture light shielding part 100 does not have a mechanical movable part. The variable aperture light-shielding unit 100 includes two transparent substrates 102 and 104 facing each other, a transparent electrode layer, and a layer of a material having electrochromic characteristics (hereinafter referred to as an “EC layer”). "). The transparent electrode layer is formed on the inner surfaces of the transparent substrates 102 and 104 facing each other. Therefore, the two transparent electrode layers are also arranged to face each other. The EC layer is formed between the transparent electrodes facing each other. The transparent electrode and the EC layer are not shown. The variable aperture light shielding unit 100 is connected to an EC element driver via a flexible printed circuit board (FPC) 106. A segment is formed by a pair of opposing transparent electrodes having a certain contour shape and an EC layer existing therebetween. A voltage having a predetermined polarity and a predetermined potential is applied to the pair of transparent electrodes facing each other. Thereby, an oxidation / reduction reaction occurs in the EC layer, and the transmittance (optical density) of the EC layer can be changed. The shape of the segment is defined by the contour shape of a pair of opposing transparent electrodes.

  The variable aperture light shielding unit 100 is incorporated in the optical system. At this time, the variable aperture light shielding unit 100 is disposed so that the plane orthogonal to the optical axis of the optical system and the transparent substrates 102 and 104 are substantially parallel. The optical axis is assumed to extend in the direction orthogonal to the paper surface in FIG. The variable aperture light shielding unit 100 includes a plurality of segments 108a, 108b, 108c, and 108d. Each of the plurality of segments 108a, 108b, 108c, and 108d has a substantially rectangular frame shape. These segments 108a to 108d are arranged in a nested manner with the optical axis O as the center. The shape of each of the segments 108a to 108d can be changed in size so as to maintain a similar relationship. Note that the shape and number of segments shown in (b) of FIG. 1A are merely examples, and can have any shape and number of segments. FIG. 1B (c) shows a variable aperture light shielding unit 100A as another example. The variable aperture light shielding part 100A has a segment shape different from that shown in FIG. In FIG. 1B (c), the same components as those shown in FIG. 1A (b) are denoted by the same reference numerals, and the description thereof is omitted. In FIG. 1B (c), the segments 108p, 108q, 108r, and 108s have segment shapes determined so that both the size (opening dimension) and the geometric shape change. That is, in the variable aperture light shielding unit 100A, the frame shape changes from a rectangle to a circle as it goes from the periphery to the center.

  The segments 108a to 108d and the segments 108p to 108s are configured such that the respective transmittances can be controlled independently. The fixed opening 110 is always in a light shielding state. In the example shown in (b) of FIG. 1A, by setting all of the segments 108a to 108d to the light-transmitting state, the aperture set by the variable aperture light shielding unit 100 becomes the largest. The opening at this time is defined by the opening shape of the fixed opening 110. On the other hand, by setting all of the segments 108a to 108d to the light shielding state, the aperture set by the variable aperture light shielding unit 100 becomes the smallest. The opening at this time is defined by the inner contour of the segment 108d having a frame shape. By sequentially switching from this state to the segment 108d, the segment 108c, the segment 108b, and the segment 108a from the light shielding state to the light transmitting state, the size of the opening set in the variable aperture light shielding unit 100 can be increased.

  In the example shown in (c) of FIG. 1B, the aperture set by the variable aperture light shielding unit 100 becomes the largest by setting all the segments 108p to 108s to the light-transmitting state. The opening at this time is defined by the opening shape of the fixed opening 110 and forms a substantially rectangular opening shape. On the other hand, by setting all the segments 108p to 108s to the light shielding state, the aperture set by the variable aperture light shielding unit 100 becomes the smallest. The opening at this time is defined by the inner contour of the segment 108s and forms a substantially circular opening shape. By switching from this state to the segment 108s, the segment 108r, the segment 108q, and the segment 108p sequentially from the light shielding state to the light transmitting state, the size of the aperture set in the variable aperture light shielding unit 100A can be increased while changing its shape. It becomes.

  FIG. 2 is a block diagram schematically showing the internal configuration of the digital still camera (electronic camera). In this digital still camera, a variable aperture light shielding unit 100 (100A) is incorporated. The digital still camera described here has a variable focus optical system as a photographing optical system. That is, the digital still camera has a plurality of lens groups, and the positions of some or all of the plurality of lens groups can be changed along the optical axis direction of the photographing optical system. As a result, the combined focal length of the entire optical system can be changed.

  The digital still camera has a control unit 200. The control unit 200 is connected with a zoom-up switch 202, a zoom-down switch 204, light shielding setting switches 206 and 208, an EC element driver 212, a motor driver 218, and an image processing unit 222. The EC element driver 212 is connected to the variable aperture light shielding units 100 and 100A. A zoom drive motor 220 is connected to the motor driver 218. In addition, an image sensor 320 and a video controller 214 are connected to the image processing unit 222. The video controller 214 is connected to a display device 216 such as an LCD monitor or an organic EL display monitor.

  The zoom up switch 202 or the zoom down switch 204 is operated by the photographer. In response to this operation, the control unit 200 outputs a control signal to the motor driver 218. The motor driver 218 drives the zoom drive motor 220 based on the control signal output from the control unit 200. In this manner, the zooming operation is electrically performed in the variable focus optical system in accordance with the operation of the photographer (the operation of the zoom up switch 202 or the zoom down switch 204).

  When controlling the above-described zooming operation, the control unit 200 controls the aperture state of the variable aperture light shielding units 100 and 100A via the EC element driver 212. That is, the focal length of the variable focus optical system is set by the zooming operation. Therefore, the control unit 200 outputs a control signal to the EC element driver 212 so that the aperture is in a state suitable for the set focal length. The EC element driver 212 that has received this control signal performs the light blocking state and the light transmitting state for each of the segments 108a to 108d shown in FIG. 1A (b) (or the segments 108p to 108s shown in FIG. 1B (c)). Are controlled independently. Thereby, an opening will be in an optimal opening state. Here, the optimum aperture state is a state where the aperture of the variable aperture light-shielding portion 100 (or 100A) has the smallest shape or size within a range in which the subject image is not “scratched”. Refers to that. In this state, generation of harmful light (ghost image) is suppressed. In such a state, the light shielding state and the light transmitting state are controlled in the segments 108a to 108d (or 108p to 108s). Information on the focal length of the variable focus optical system is output from a zoom encoder (not shown). The control unit 200 is configured to be able to grasp the focal length of the variable focus optical system by receiving a signal from the zoom encoder. The control unit 200 controls the opening state of the variable aperture light shielding unit 100 so as to correspond to this focal length.

  The control unit 200 outputs an imaging control signal to the image processing unit 222. The image processing unit 222 receives an image signal from the image sensor 320 in accordance with the input of the imaging control signal. Here, as the imaging device 320, for example, a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) image sensor is used. Then, the image processing unit 222 performs predetermined image processing on the image signal to obtain image data, and then outputs the image data to the video controller 214. The video controller 214 displays an image based on the image data input from the image processing unit 222 on the display device 216. The light shielding setting switches 206 and 208 will be described later.

  FIG. 3 is a diagram schematically showing the configuration and optical path of the variable focus optical system. 3A, 3B, and 3C show cases where the variable focus optical system is located at the wide position, the standard position, and the tele position, respectively. FIGS. 3A, 3B, and 3C show optical path diagrams of light beams incident on the center and the periphery of the imaging surface (corresponding to the half angle of the diagonal angle of view of the imaging surface), respectively. 3A, the variable focus optical system has a first lens group 302, a second lens group 304, and a third lens group 306 from the object side to the image side, and has a so-called three-group zoom configuration. ing. Here, the variable aperture light shielding unit 100 is disposed closer to the object side (most object side) than the first lens group 302. In addition, the variable aperture light shielding unit 100 </ b> A is disposed between the first lens group 302 and the second lens group 304. The variable aperture light shielding unit 100, the first lens group 302, the variable aperture light shielding unit 100A, the second lens group 304, and the third lens group 306 are held by a lens holding device (not shown). Among these elements, the variable aperture light-shielding part 100 and the variable aperture light-shielding part 100A are configured integrally with the first lens group 302 so as to be movable along the optical axis direction. The positions along the optical axis direction of the first lens group 302, the second lens group 304, and the third lens group 306 are controlled by a zoom cam (not shown) or the like. Then, the zoom cam or the like is driven by the zoom drive motor 220 described above, and the variable magnification operation of the variable focus optical system is performed. An infrared light cut filter 308, an optical low-pass filter (OLPF) 310, and an image sensor 320 are disposed behind the variable focus optical system. Reference numeral 312 denotes a fixed aperture, which is not shown in FIGS. 3A, 3B, and 3C, but a lens shutter is disposed near the fixed aperture 312 at a position on the object side. In FIG. 3A to FIG. 3C, reference numerals A1, A2,..., A6 schematically show the shape of the aperture set by the variable aperture light shielding portions 100, 100A.

  This will be described with reference to FIGS. 3A to 3C. In the wide (wide-angle) position shown in FIG. 3A, the first lens group 302 and the second lens group 304 are relatively far apart. Therefore, the angle formed by the light beam (axial principal ray) incident on the imaging surface center P0 and the light beam (off-axis principal ray) incident on the imaging surface diagonal P1 is relatively large. In this case, the light beam incident from the object side toward the diagonal of the imaging surface passes through a position away from the optical axis. That is, this light beam passes through a relatively large radial position on the surfaces of the lenses 314 and 316 constituting the first lens group 302. For this reason, the apertures set by the variable aperture light-shielding portions 100 and 100A (indicated by reference signs A1 and A2 in FIG. 3A) are set to be relatively large.

  In the standard position shown in FIG. 3B, the first lens group 302 and the second lens group 304 are closer than in the wide position. Therefore, the angle formed by the light beam incident on the center P0 of the imaging surface and the light beam P1 incident on the diagonal of the imaging surface is also smaller than that in the wide position. In other words, the light beam incident from the object side toward the diagonal of the imaging surface passes through a position closer to the optical axis of the lenses 314 and 316 than in the case of the wide position. For this reason, the apertures set by the variable aperture light-shielding portions 100 and 100A (indicated by reference symbols A3 and A4 in FIG. 3B) are set smaller than in the wide state. In addition, since the exit surface of the lens 316 and the position of the fixed diaphragm 312 are close to each other, the radius of the corner portion of the opening can be set large. In the variable aperture light-shielding portion 100A shown in FIG. 1B (c), when the segments 108p, 108q and 108r are set in the light-shielding state and the segment 108s is set in the light-transmitting state, they are indicated by reference numeral A4 in FIG. 3B. It becomes such an opening shape.

  In the tele (telephoto) position shown in FIG. 3C, the first lens group 302 and the second lens group 304 are further closer than in the standard position. Therefore, the angle formed by the light beam incident on the imaging surface center P0 and the light beam incident on the imaging surface diagonal P1 is further smaller than that in the standard state. In other words, the light beam incident from the object side toward the diagonal of the imaging surface passes through the positions closer to the optical axis of the lenses 314 and 316 than in the standard state. For this reason, the apertures set by the variable aperture light-shielding portions 100 and 100A (shown with reference numerals A5 and A6 in FIG. 3C) are set smaller. In addition, since the exit surface of the lens 316 and the position of the fixed aperture 312 are closer, the opening shape can be set to a substantially circular shape. In the variable aperture light shielding part 100A shown in FIG. 2, when all of the segments 108p, 108q, 108r, and 108s are set in the light shielding state, the opening shape is as shown by reference numeral A6 in FIG. 3C.

  As is clear from the above description, in the ghost reduction apparatus according to the present embodiment, the light shielding members of the variable aperture light shielding units 100 and 100A are configured by EC elements. Therefore, the ghost reduction device according to the present embodiment does not have a mechanical part. For this reason, a mechanism for driving the diaphragm blades according to the set focus (zoom position) of the variable focus optical system or moving the light shielding portion along the optical axis direction becomes unnecessary. Therefore, in the ghost reduction device according to the present embodiment, it is possible to achieve the miniaturization and the simplification of the configuration of the variable focus optical system. In addition, since the variable aperture light-shielding portions 100 and 100A can freely change the aperture shape, harmful light can be removed more finely.

  In addition, the opening shape that can be set by the variable opening light shielding units 100 and 100A can be set to an arbitrary shape such as a rectangle, a barrel, a pincushion, an ellipse, a long hole, or a circle. In addition, when changing the opening shape, the geometric shape can be made different, or the opening size can be proportionally reduced or proportionally enlarged while keeping the geometric shape constant. For this reason, in the ghost reduction device according to the present embodiment, it is possible to define the aperture shape so as to effectively block harmful light while guiding only the original light beam for image formation to the imaging surface. . As a result, the ghost reduction apparatus according to the present embodiment can improve the quality of the generated image.

  The example in which the variable aperture light shielding units 100 and 100A are configured separately from the lens elements configuring the variable focus optical system has been described above. However, for example, EC elements may be directly formed on the entrance surface of the lens 314 and the exit surface of the lens 316. As described above, the variable aperture light shielding portions 100 and 100A may integrally form the lens and the variable aperture light shielding portion.

  In the above description, segments having a predetermined outer shape are used in order to define the aperture shape, and the variable aperture light-shielding portions 100 and 100A are configured by a combination of the segments. However, regarding the shape and arrangement of segments, fine rectangular segments are arranged in a grid, triangular segments are arranged alternately, hexagonal segments are arranged in a honeycomb, or multiple types It is also possible to arrange the segments in the form of densely arranged. FIG. 4 shows an example in which square segments 108f (EC elements) are arranged in a grid. By comprising in this way, the light-shielding member for demarcating opening shape is realizable. In FIG. 4, the same components as those shown in FIG. 1A (b) are denoted by the same reference numerals, and description thereof is omitted. In FIG. 4, the size and number of the segments 108f are merely examples, and even if more segments than those shown in FIG. Also good. In the example shown in FIG. 4, by appropriately selecting the segment to be light-transmitted and the segment to be light-shielded, for example, an opening shape as shown in FIGS. 5A, 5 </ b> B, and 5 </ b> C is formed. It becomes possible to set. In each of FIGS. 5A, 5B, and 5C, the rectangle drawn at the top shows the opening shape when all segments are in a transparent state (fully open state) (schematically). The figure shown in FIG. Moreover, in the opening shape shown below from the second, and below it, the opening shape of a full open state is shown with the dashed-two dotted line, and the opening shape after a change is shown with the continuous line.

  FIGS. 5A and 5B show the apertures shown in FIGS. 1A and 1B by controlling the light transmission state and the light shielding state of the segments arranged in a grid. An example in which a shape similar to the shape is set is shown.

  In (b) of FIG. 1A, (c) of FIG. 1B, and (a) and (b) of FIG. 5, when changing the aperture shape, a rotationally symmetric shape is maintained with respect to the optical axis O as a reference. An opening shape is defined. However, as shown in FIG. 5C, it is also possible to change the aperture shape in a non-rotationally symmetric shape (a state where the rotation symmetry shape is not maintained) with respect to the optical axis O. Hereinafter, this example will be described.

  Examples of a shooting scene in which a ghost image or the like is likely to occur include a scene close to backlight and a scene in which an object or a light source having a luminance higher than the luminance of the main subject exists near the main subject. When shooting such a scene, a ghost image or the like is likely to occur. Ghost images, etc. due to harmful light can sometimes be a factor that increases the artistry of photography. However, harmful light often forms undesired ghost images. Therefore, it is preferable to remove harmful light as much as possible.

  On the other hand, if the aperture of the variable aperture light-shielding portion 100, 100A or 100B is too narrow to shield harmful light, the luminous flux incident on the peripheral portion of the screen is lost, leading to a decrease in the amount of peripheral light, or lacking in the peripheral portion of the image. There are also times when However, it may be desirable if the ghost can be reduced or eliminated even if the amount of peripheral light is reduced or the peripheral portion of the image is missing. Particularly in digital photography, it is possible to correct a decrease in peripheral light amount by retouching image processing technology, or to trim a portion where an image is missing.

  In addition to video cameras, digital still cameras display live images and live views on display devices. With such a display method, it is possible to display an image captured by the image sensor in almost real time. Therefore, for example, in the block diagram shown in FIG. 2, the variable aperture light shielding units 100 and 100A are replaced with the variable aperture light shielding unit 100B. By combining the variable aperture light shielding unit 100B and the display in real time, the photographer can view the image displayed on the display device 216 while changing the aperture shape of the variable aperture light shielding unit 100B. By doing so, it becomes possible to confirm a ghost reduction effect when the aperture shape of the variable aperture light-shielding portion 100B is changed, a chip in the peripheral portion of the image, or the like. Here, when changing the aperture shape of the variable aperture light shielding unit 100B, the photographer operates the light shielding setting switches 206 and 208. These light shielding setting switches 206 and 208 can be disposed on the back of the digital still camera, for example. In this case, when the digital still camera is viewed from the back side, the light shielding setting switch 206 can be configured to swing in the horizontal direction, and the light shielding setting switch 208 can be configured to swing in the vertical direction. The photographer performs an operation of specifying the side to be adjusted among the upper side, the lower side, the left side, and the right side of the opening, and then operates the light shielding setting switch 206 or 208 to adjust the opening shape. By having such a configuration, it is possible to effectively generate a ghost image according to the composition at the time of photographing (vertical composition, horizontal composition) and the photographing scene (for example, the position of a high-intensity light source within the photographing range). It becomes possible to suppress.

  It is preferable that at least one of a manual operation mode and an automatic setting mode is provided for the operation of the aperture shape in the variable aperture light shielding unit 100B. The manual operation mode is a mode in which the photographer performs the setting as described above. The automatic setting mode is a mode in which the shape and dimensions of the aperture are automatically set in accordance with the zooming operation of the variable focus optical system. Only one of the modes may be provided, or both modes may be provided.

  In addition, the image processing unit 222 can be used to remove harmful light more effectively. An image signal is input to the image processing unit 222 from the image sensor 320. Therefore, the input image signal is automatically analyzed by the image processing unit 222. If generation of a ghost image is recognized by this analysis, the shape and size of the aperture formed by the variable aperture light shielding unit 100B may be controlled. The digital still camera may be configured to output this control information from the image processing unit 222 to the control unit 200. In this case, the photographer decides whether to give priority to ghost reduction to allow some light drop or chipping around the image, or to give priority to avoiding light drop or chipping around the screen. It is also possible to select in advance.

  Note that if the aperture of the variable aperture light-shielding portion 100B is set too small, a phenomenon may occur in which the amount of light around the image decreases. When such a phenomenon is recognized, the image processing unit 222 may perform a correction process (peripheral light amount decrease correction) to reduce the influence of the light amount decrease. Alternatively, the image processing unit 222 may output a command signal for correcting the exposure amount to the control unit 200 so as to reduce the influence of the light amount reduction. The control unit 200 having received a command signal for correcting the exposure amount controls a shutter (not shown) to change the setting of the aperture or shutter speed. In this way, the obtained image may be corrected so as to increase the exposure amount in a range where whiteout due to overexposure is not significant. The command signal for correcting the exposure amount may be output from a photometry unit (not shown).

  In the example described above, a transparent substrate having a circular contour shape is used for the substrates of the variable aperture light shielding portions 100, 100A, and 100B. However, the substrate may have a rectangular shape or other geometric shapes depending on the structure of the lens frame or the lens barrel that holds the optical system. The variable aperture light shielding part may be one in which a segment is formed on such a transparent substrate.

  The example in which the ghost reduction device according to the present embodiment is incorporated in the variable focus optical system and the aperture shape and dimensions of the variable aperture light shielding unit are changed according to the zooming operation has been described above. However, it can also be applied to a single-focus optical system. For example, the aperture shape and size of the variable aperture light shielding portion can be changed according to the amount of extension of the focusing lens. In particular, macro lenses and telephoto lenses have a large amount of lens movement during focusing. Therefore, in such an optical system, the ghost reduction device according to the present embodiment can sufficiently exhibit the effect.

  Further, the example in which the ghost reduction device according to the present invention is incorporated in a digital still camera has been described above, but it can also be applied to a movie camera. Moreover, it is applicable also to the camera using a silver salt film. Furthermore, the ghost reduction apparatus according to the present invention can be incorporated not only in the photographing apparatus but also in an optical system such as a telescope, binoculars, or a microscope.

  The ghost reduction apparatus according to the present invention can be used for a photographic lens for still or movie shooting. Further, it can be used for an optical system such as a zoom type or a magnification switching type binoculars, a telescope, or a microscope. Further, it can be used for a zoom type or magnification switching type projection lens used for a video projector or the like.

It is a figure which shows roughly the external appearance of the variable aperture light-shielding part which comprises the ghost reduction apparatus which concerns on embodiment of this invention, (a) is the perspective view, (b) is a figure which shows a top view. It is a figure explaining the example from which the segment shape which comprises a variable aperture light-shielding part differs. It is a block diagram which shows the example of a schematic structure at the time of incorporating a ghost reduction apparatus in a digital still camera. It is a figure explaining the lens structure and optical path of a variable focus optical system incorporating a variable aperture light shielding part, and is a diagram showing a case where the variable focus optical system is in a wide position. It is a figure explaining the lens structure and optical path of a variable focus optical system incorporating a variable aperture light shielding part, and is a diagram showing a case where the variable focus optical system is in a standard position. It is a figure explaining the lens structure and optical path of a variable focus optical system incorporating a variable aperture light shielding part, and is a diagram showing a case where the variable focus optical system is in a tele position. It is a figure explaining the example which arranged the segment shape of EC element which defines the opening shape of a variable aperture light-shielding part as a rectangular shape, and arranged it in the shape of a grid. It is a figure explaining the example of the shape of the opening which can be formed with the variable opening light-shielding part shown in FIG.

Explanation of symbols

100, 100A, 100B Variable aperture light shielding part 102, 104 Transparent substrate 106 FPC
108a-108d, 108f, 108p-108s Segment 110 Fixed opening 200 Control unit 202 Zoom-up switch 204 Zoom-down switch 206, 208 Shading setting switch 212 EC element driver 214 Video controller 216 Display device 222 Image processing unit 302 First lens group 304 Second lens group 306 Third lens group 308 Infrared light cut filter 310 OLPF
314, 316 Lens 320 Image sensor

Claims (7)

A variable aperture light-shielding portion capable of changing at least one of the size and shape of an aperture for restricting the light flux of light traveling backward in the optical system;
The variable aperture light shielding unit includes an EC element including a plurality of segments, and is configured to be able to independently control the light transmittance of the plurality of segments. A ghost reduction device characterized in that at least one of the size and shape of the opening is formed by one or a plurality of segments set in a low state.   The optical system has one or a plurality of lens elements, and the size and shape of the opening according to a change in the position of some or all of the lens elements along the optical axis of the optical system. The ghost reduction device according to claim 1, wherein at least one of the two is configured to be changeable.   The optical system has a plurality of lens groups, and a part or all of the plurality of lens groups is synthesized as a whole optical system by changing the position along the optical axis direction of the optical system. A variable focal length optical system capable of changing a focal length, and configured to change at least one of a size and a shape of the opening in accordance with a change in the position of some or all of the plurality of lens groups. The ghost reduction apparatus according to claim 1.   The ghost reduction apparatus according to any one of claims 1 to 3, wherein the optical system is a photographing optical system.   5. The ghost reduction apparatus according to claim 1, further comprising an opening changing operation unit that allows a user to change at least one of a size and a shape of the opening. An electronic camera comprising the ghost reduction device according to claim 5,
An image sensor for converting a subject image formed by the optical system into an electrical signal;
A monitor device capable of displaying an image based on an electrical signal output from the image sensor;
An electronic camera configured to allow the user to change at least one of the size and shape of the opening by operating the opening changing operation unit while observing an image displayed on the monitor display device. An electronic camera comprising the ghost reduction device according to claim 5,
An image sensor for converting a subject image formed by the optical system into an electrical signal;
An image analysis unit that analyzes an image based on an electrical signal output from the image sensor and determines the presence or absence of the harmful light; and
When it is determined by the image analysis unit that the harmful light is present, an opening control unit that controls to change at least one of the size and shape of the opening so as to reduce the influence of the harmful light on the image. And an electronic camera.

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