JP2007110530A - Electronic camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic camera which reduces reflection of a foreign matter adhered to an optical low-pass filter and whose camera casing is thinned. <P>SOLUTION: In photography, a zoom lens unit 11 extends and spacing is held between a rear group lens frame 118 which holds a rear group lens 18 and a pressure plate 204. Thus, since a filter base 202 is not compressed, an OLPF 28 is located at a predetermined position where spacing between a CCD unit 26 and the OLPF 28 becomes predetermined distance. Consequently, since an image becomes in so-called a blurred state even when the foreign matter such as dust is adhered to the OLPF 28, the dust becomes a shadow and hard to be reflected on a photographed image. On the other hand, in non-photography, the zoom lens unit 11 sinks and the rear group lens frame 118 which holds the rear group lens 18 moves to the arrowed XB direction. Then, the rear group lens frame 118 abuts on and pushes the pressure plate to transfer the OLPF 28 to an adjacent position adjacent to a CCD unit 26. A digital camera 110 can be miniaturized for compression of the filter base 202. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electronic camera.

  Some digital cameras employ a retractable lens unit for thinning when not in use (when not photographing). In such a digital camera, when the power is turned off, the lens unit is stored in the camera housing, and when the power is turned on, the lens unit is extended and protruded to be in a standby state where photographing can be performed.

  In order to further reduce the thickness of the digital camera when not in use, a configuration in which a part of the lens is retracted out of the optical axis and a configuration in which the optical axis is refracted when the lens unit is moved are proposed.

  On the other hand, in order to prevent the occurrence of moire, an optical low-pass filter that removes high-frequency components of photographing light is arranged in front of the CCD. Then, foreign matters such as dust may adhere to the optical low-pass filter. When the optical low-pass filter and the CCD are close to each other, this foreign substance becomes a shadow and appears in the photographed image. However, if the optical low-pass filter and the CCD are separated from each other, a so-called out-of-focus state occurs, so that it becomes difficult to take a shadow. Therefore, the optical low-pass filter and the CCD need to be separated by a predetermined distance or more.

  However, in order to reduce the thickness of the digital camera, it is desirable to bring the optical low-pass filter and the CCD close to each other. However, as described above, the foreign matter adhering to the optical low-pass filter tends to appear as a shadow, so it cannot be brought close to each other. .

In addition, although the structure which moves an optical low-pass filter in the direction orthogonal to an optical axis direction is proposed, since such a structure requires the space which moves an optical low-pass filter, in order to miniaturize a digital camera Does not contribute. (For example, refer to Patent Document 1 and Patent Document 2).
Japanese Patent Laid-Open No. 07-203288 JP 2000-595656 A

  The present invention has been made to solve the above-described problems, and an object thereof is to reduce the thickness of an electronic camera.

  The electronic camera according to claim 1, an imaging device housing, a lens unit that extends and sinks in the optical axis direction from the imaging device housing, and a projection length changes, and a subject image formed by the lens unit And an optical low-pass filter that is disposed in front of the image sensor and is movable in the direction of the optical axis. The optical low-pass filter is interlocked with expansion and settling of the lens unit. The filter is characterized in that it moves to a predetermined position where a distance from the image sensor becomes a predetermined distance and a close position close to the image sensor.

  In the electronic camera according to the first aspect, the optical low-pass filter disposed in front of the image sensor is movable in the optical axis direction. The optical low-pass filter moves in conjunction with the extension and settling of the lens unit to a predetermined position where the distance from the image sensor becomes a predetermined distance and a close position close to the image sensor.

  When foreign matter such as dust adheres to the optical low-pass filter, it becomes a shadow and appears in the photographed image. This reflection becomes more conspicuous as the distance between the optical low-pass filter and the image sensor becomes shorter, and becomes less noticeable when the interval is increased. The inconspicuous distance is a predetermined distance, and the position of the optical low-pass filter at this time is the predetermined position.

  Therefore, when the lens unit is extended, the optical unit is set at a predetermined position where the distance between the optical filter and the image sensor is a predetermined distance in order to alleviate the reflection of foreign matter such as dust attached to the optical low-pass filter, and the lens unit is sunk. In this state, the optical low-pass filter moves in the optical axis direction and moves to a close position close to the imaging device.

  As described above, the optical low-pass filter is moved from the predetermined position to the close position in conjunction with the sinking of the lens unit, so that the thickness can be reduced.

  Further, when the lens unit is extended, the optical low-pass filter is in a predetermined position, so even if foreign matter such as dust adheres to the optical low-pass filter, it becomes a shadow and the captured image is not conspicuous.

  According to a second aspect of the present invention, there is provided the electronic camera according to the first aspect, wherein the lens unit is moved between the moving member that moves in the optical axis direction along with the extension and settling of the lens unit, the imaging element, and the optical low-pass filter. And the elastic member is compressed by the movement of the moving member in the optical axis direction as the lens unit sinks, and the elastic member is compressed by the moving member. The elastic member is restored when the moving member moves in the optical axis direction along with the extension of the lens unit, and the optical low-pass filter moves to the predetermined position.

  In the electronic camera according to the second aspect, the moving member moves in the optical axis direction with the settling of the lens unit, so that the elastic member is compressed by being pushed by the moving member, and the optical low-pass filter moves to the close position. Further, when the moving member moves in the optical axis direction along with the extension of the lens unit, the elastic member is restored, and the optical low-pass filter moves to a predetermined position.

  With such a simple configuration, the optical low-pass filter can be moved to a predetermined position and a proximity position in conjunction with the extension and settling of the lens unit.

  According to a third aspect of the present invention, in the electronic camera according to the second aspect, the elastic member seals between the optical low-pass filter and the imaging device.

  In the electronic camera according to claim 3, the elastic member seals between the optical low-pass filter and the image sensor. Therefore, foreign matter such as dust does not adhere to the image sensor.

  As described above, according to the present invention, the optical low-pass filter can be thinned by moving from a predetermined position to a close position.

  A digital still camera 110 (hereinafter abbreviated as “digital camera 110”) according to an embodiment of the present invention will be described.

  As shown in FIG. 1, on the front of the digital camera 110, a strobe 112 that is emitted when the subject has low illuminance and an appropriate amount of exposure light cannot be obtained at the time of exposure, and an image that is substantially equivalent to the subject image to be photographed. A finder window 114 through which the light shown is incident and a lens barrier 116 that can be opened and closed to protect the front lens group 16 (see FIG. 1B) are provided.

  On the upper surface of the digital camera 110, a power switch 124 that switches supply / stop of power supply to each part of the digital camera 110 and a shutter that is pressed by the photographer when performing shooting as a shooting instruction button. A switch (so-called release button) 126 is provided.

  On the side of the digital camera 110, a slot (not shown) for loading a portable recording medium (in this embodiment, smart media) that stores image data obtained by shooting as digital data into the digital camera 110. Is provided.

  On the back of the digital camera 110, a subject image obtained by photographing, various menus, a liquid crystal display (not shown) for displaying parameters relating to image processing, messages, and the like, a cursor button, and a viewfinder eyepiece that is viewed by the photographer (Not shown) and the like are provided.

  In addition, as shown in FIG. 1B, the digital camera 110 includes a zoom lens unit 11 with a two-stage pay-out optical zoom function. In the digital camera 110, the above-described lens barrier 116 (see FIG. 1A) is opened at the time of photographing, the front group lens 16 appears outside, and the retracted inner cylinder 15 and outer cylinder 14 of the zoom lens unit 11. And extend. That is, the zoom lens unit 11 is extended from the camera housing 12 and extended (projected) during use, but the zoom lens unit 11 is stored in the camera housing 12 when not in use. . Therefore, the digital camera 110 when not in use is thinned.

  Now, FIG. 3B is an internal schematic diagram of FIG. 1A where the zoom lens unit 11 is retracted and stored, and FIG. 1 is a state where the zoom lens unit 11 is extended and extended. FIG. 3A is a schematic diagram of the inside at (B).

  As shown in FIGS. 2 and 3, a CCD unit 26 made up of a CCD 22, a cover glass 24, etc., which is an image pickup device, is attached to the CCD base 200 inside the digital camera 110. The CCD 22 has a large number of photodiodes (not shown) arranged in a plane and has a predetermined color filter arrangement structure (for example, honeycomb arrangement, Bayer arrangement, etc.). In front of the CCD unit 26, an optical low-pass filter 28 (hereinafter referred to as an OLPF 28) that removes high-frequency components of photographing light is disposed in order to prevent the occurrence of moire.

  A window frame-shaped filter base 202 having a hole 202B formed in a portion corresponding to the CCD unit 26 is adhesively bonded to the CCD base 200. A rib portion 202A (see FIG. 3) is formed on the outer peripheral portion of the rear surface of the filter base 202, and this rib portion 202A is configured to fit into a recess 200A formed in the CCD base 200.

  The filter base 202 is made of an elastic member that is elastically deformed, such as a sponge. The inner peripheral portion of the hole 202B on the front surface of the filter base 202 has a stepped shape, and the OLPF 28 is adhesively bonded to the surface 202C lowered by one step. For this reason, the forefront surface of the filter base 202 and the front surface of the OLPF 28 are substantially the same surface.

  Further, a window frame-shaped presser plate 204 in which holes corresponding to the CCD unit 26 are formed is attached to the front surfaces of the OLPF 28 and the filter base 202. (The presser plate 204 is positioned at the forefront). The presser plate 204 is made of metal or resin and has higher rigidity than the OLPF 28.

  In addition, the filter base 202 is configured to seal the space between the CCD unit 26 and the OLPF 28.

  As shown in FIGS. 3A and 4A, when the zoom lens unit 11 is extended (FIG. 1B), the rear lens group frame 118 holding the rear lens group 18 and The presser plate 204 is spaced apart.

  In this state, the OLPF 28 is positioned at a predetermined position having a predetermined distance between the CCD unit 26 and the OLPF 28. The predetermined distance is about 1.0 mm to 2.0 mm.

  As shown in FIGS. 3B and 4B, when the zoom lens unit 11 is moved down, the rear lens group frame 118 holding the rear lens group 18 is moved in the direction indicated by the arrow XB (the same direction as the optical axis 201). ) When the rear group lens frame 118 moves, the rear group lens frame 118 comes into contact with and presses the presser plate 204 to compress the filter base 202, and the OLPF 28 approaches the CCD unit 26. Even when the filter base 202 is compressed in this way, the rib base 202A on the outer peripheral portion of the filter base 202 fits into the concave portion 200A of the CCD base 200, so that the filter base 202 does not shift. Moreover, since it is pressed through the highly rigid presser plate 204, the filter base 202 is uniformly compressed.

  Note that the distance between the CCD unit 26 and the OLPF 28 in this close state is about 0.5 mm. Further, the position of the OLPF 28 at this time is set as a proximity position.

  When the zoom lens unit 11 is extended and extended (FIG. 1B), as shown in FIGS. 3A and 4A, the rear lens group frame 118 is in the XA direction (the same direction as the optical axis 201). And the filter base 202 is restored, and the OLPF 28 moves to a predetermined position where the distance between the CCD unit 26 and the OLPF 28 is a predetermined distance.

  Next, the operation of this embodiment will be described.

  At the time of shooting, the zoom lens unit 11 extends as shown in FIGS. 1B and 4B, and the rear lens group 18 is held as shown in FIGS. 3A and 4A. The rear lens group frame 118 and the presser plate 204 are spaced apart from each other. Therefore, since the filter base 202 is not compressed, the OLPF 28 is located at a predetermined position where the distance between the CCD unit 26 and the OLPF 28 is a predetermined distance (about 1.0 mm to 2.0 mm).

  Therefore, even if foreign matter such as dust adheres to the OLPF 28, a so-called out-of-focus state occurs, and this dust becomes a shadow and is difficult to appear in the photographed image.

  On the other hand, at the time of non-photographing, the zoom lens unit 11 sinks as shown in FIG. 1A, and the rear lens group 18 is held as shown in FIGS. 3B and 4B. The rear lens group frame 118 is moved in the arrow XB direction. Then, the rear lens group frame 118 comes into contact with and presses the presser plate 204, compresses the filter base 202, and moves the OLPF 28 to a close position close to the CCD unit 26.

  Therefore, the digital camera 110 can be thinned by compressing the filter base 202 (in this embodiment, 1.5 mm to 0.5 mm obtained by subtracting 0.5 mm from 2.0 mm to 1.0 mm).

  In this way, the OLPF 28 is linked to the CCD unit 26 at a predetermined position (FIGS. 1A, 3B, and 4) as the zoom lens unit 11 is extended and retracted. B)) and a proximity position close to the CCD unit 26 (FIG. 1B, FIG. 3A, FIG. 4B).

  Therefore, the digital camera 110 is thinned by the amount of movement of the OLPF 28 in the direction of the optical axis 201. In other words, there is a contradiction between the mitigation of reflection of foreign matter adhering to the OLPF 28 in the photographed image and the thinning of the camera housing 12 (which is conventionally difficult to achieve due to a trade-off relationship). Yes.

  Further, since the filter base 202 seals and seals between the CCD unit 26 and the OLPF 28, foreign matter such as dust does not adhere to the CCD unit 26.

  Next, a digital camera according to the second embodiment of the present invention will be described.

  The first embodiment differs from the first embodiment in the configuration of the filter base and the vicinity thereof, and the other configurations are the same. Therefore, the overlapping description is omitted.

  As shown in FIG. 5, the inner peripheral portion of the hole 220 </ b> B on the rear surface of the filter base 220 has a stepped shape, and the OLPF 28 is adhesively bonded to the surface 220 </ b> C that is lowered by one step. Therefore, the rear surface of the filter base 220 and the rear surface of the OLPF 28 are substantially the same surface. The presser plate 204 (see FIGS. 3 and 4) is not attached.

As in the first embodiment, as shown in FIG. 5B, when the zoom lens unit 11 (see FIG. 1A) is moved down, the rear group lens holding the rear group lens 18 is used. The frame 118 moves in the arrow XB direction (the same direction as the optical axis 201). When the rear lens group frame 118 moves, it abuts against the filter base 220 and compresses, and the OLPF 28 abuts against the CCD base 200 and approaches the CCD unit 26. When the zoom lens unit 11 is extended and extended (FIG. 1 (B)). As shown in FIG. 5A, the rear lens group frame 118 moves in the XA direction (the same direction as the optical axis 201) and moves away from the filter base 220, and a predetermined distance is set between the CCD unit 26 and the OLPF 28. The OLPF 28 moves to the position.

  Next, the operation of this embodiment will be described.

  As can be seen from a comparison between FIG. 4B and FIG. 5B, in this embodiment, the OLPF 28 contacts the CCD base 200. Therefore, the OLPF 28 in this embodiment is more CCD than the first embodiment. Closer to unit 26. That is, it is thinner than the first embodiment.

  In this way, in this embodiment, the OLPF 28 is closer to the CCD unit 26 than in the first embodiment. However, since the first embodiment has the push plate 204, the orientation of the filter base, that is, the orientation of the OLPF is More stable than the embodiment.

  Next, a digital camera according to a third embodiment of the present invention will be described.

  In addition, the same code | symbol is used for the same member as 1st and 2nd embodiment, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 6, the filter base 320 has a window frame shape and is made of metal, resin, or the like. The OLPF 28 is joined to the filter base 320. The rear surface of the filter base 320 and the rear surface of the OLPF are the same surface. Holes 320 </ b> A are formed at the four corners of the filter base 320. A cylindrical pin 322 standing from the CCD base 200 passes through the hole 320A. The tip of the pin 322 is formed with a flange portion 322A having an outer diameter larger than that of the hole 320A. Further, a compression spring 324 is inserted through the pin 322. The longitudinal direction of the pin 322 is parallel to the optical axis 201.

  With this configuration, the filter base 320 is urged toward the flange 322A by the compression spring 324. In this state, the OLPF 28 is located at a predetermined position where the distance between the CCD unit 26 and the OLPF 28 is a predetermined distance (about 1.0 mm to 2.0 mm).

  Further, as shown in FIG. 6B, the rear lens group frame 118 holding the rear lens group 18 moves in the direction of the arrow XB by the sinking of the zoom lens unit 11 (see FIG. 1A). . When the rear lens group frame 118 moves, it abuts against the filter base 320 and presses it, compresses the compression spring 324 and moves the OLPF 28 to a close position close to the CCD unit 26.

  Note that the space between the OPLF 28 and the CCD unit 26 is not hermetically sealed only with this configuration. Therefore, it is desirable to provide a sealing member with a separate sealing member.

  For example, an air seal is provided between the hole 200A and the pin 322, and a bellows member 329 that connects the CCD base 200 to the periphery of the filter base 320 is provided to form a sealed structure.

  Next, the operation of this embodiment will be described.

  The OPLF 28 moves along a pin 322 parallel to the optical axis 201. Therefore, it moves along the optical axis 201 more accurately. Further, since the filter base 320 is a rigid body made of metal or resin, the posture of the OPLF 28 is very stable. Further, the OPLF 28 comes closer to the CCD unit 26.

  The present invention is not limited to the above embodiment.

  The OLPF moves in the optical axis direction in conjunction with the zoom lens unit 11, but is not limited to the mechanism of the above embodiment. The OLPF may be a mechanism that moves in the optical axis direction via a link or a cam.

The digital camera which concerns on 1st embodiment of this invention is shown, (A) shows the state which the zoom lens unit was sunk and stored, (B) is the figure which shows the state which the zoom lens unit extended and extended. It is. It is a disassembled perspective view of the principal part inside the digital camera which concerns on 1st embodiment of this invention. The main part inside the digital camera which concerns on 1st embodiment of this invention is shown, (A) is an optical low-pass filter located in a predetermined position, (B) is a figure where the optical low-pass filter is located in a proximity position. It is. It is the figure which expanded the principal part inside the digital camera which concerns on 1st embodiment of this invention, (A) is an optical low-pass filter located in a predetermined position, (B) is an optical low-pass filter located in a proximity position. FIG. It is the figure which expanded the principal part inside the digital camera which concerns on 2nd embodiment of this invention, (A) has an optical low-pass filter located in a predetermined position, (B) has an optical low-pass filter located in a proximity position. FIG. It is the figure which expanded the principal part inside the digital camera which concerns on 3rd embodiment of this invention, (A) is an optical low-pass filter located in a predetermined position, (B) is an optical low-pass filter located in a proximity position. FIG.

Explanation of symbols

11 Zoom lens unit (lens unit)
12 Camera housing (imaging device housing)
22 CCD (imaging device)
28 Optical low-pass filter 110 Digital still camera (electronic camera)
118 Rear lens group frame (moving member)
201 Optical axis 202 Filter base (elastic member)
220 Filter base (elastic member)
324 Compression spring (elastic member)

Claims (3)

An imaging device housing;
A lens unit that extends and sinks in the direction of the optical axis from the imaging device housing, and the protrusion length changes;
An image sensor that converts an object image formed by the lens unit into an electrical signal;
An optical low-pass filter that is disposed in front of the image sensor and is movable in the optical axis direction;
With
In conjunction with the extension and sinking of the lens unit,
An electronic camera, wherein the optical low-pass filter moves to a predetermined position where a distance from the image sensor is a predetermined distance and a close position close to the image sensor. A moving member that moves in the direction of the optical axis along with the extension and sinking of the lens unit;
An elastic member disposed between the imaging element and the optical low-pass filter;
With
When the moving member moves in the optical axis direction along with the settling of the lens unit, the elastic member is compressed by being pushed by the moving member, and the optical low-pass filter is moved to the proximity position,
2. The electronic camera according to claim 1, wherein the elastic member is restored by moving the moving member in the optical axis direction along with the extension of the lens unit, and the optical low-pass filter is moved to the predetermined position.   The electronic camera according to claim 2, wherein the elastic member seals between the optical low-pass filter and the imaging device.

Images