JP2002122902A - Filter holding mechanism and image pickup device equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter holding mechanism which is capable of solving the problem that cost rises or a camera gets larger and has excellent maintainability, and an image pickup device equipped therewith. SOLUTION: An optical filter 17 is held on a photographing optical path through a filter holding member 16. The member 16 where an aperture part for fitting and holding the filter 17 is formed is provided with a plane part 16a formed around the aperture edge in the specified direction of the aperture part and/or an inclined surface part 16b connected to the plane part 16a and opened and extended along an optical axis direction. The plane part 16a is set as high as or lower than the surface 17a of the filter 17 in the optical axis direction, and an angle formed between the plane part 16a and the inclined surface part 16b connected to the plane part 16a is obtuse.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the shape of a holding member for holding an optical filter in an image pickup apparatus such as a digital camera.

[0002]

2. Description of the Related Art In recent years, optical means for optically forming an image of a subject, imaging means for converting an optical subject image formed by the optical means into an electric signal, and an image of the subject taken by the imaging means A so-called digital camera having a recording unit for recording a signal and a display unit for displaying a photographed image is widely recognized as one of image recording or image display units like a silver halide camera and a video camera. It became so.

In the case of a digital camera using such a solid-state imaging device, an optical filter for correcting the spectral sensitivity characteristics of the solid-state imaging device is generally arranged on a photographic optical path between a photographic lens and the solid-state imaging device. This optical filter is arranged on the imaging optical path between infrared rays, which cuts infrared components. This optical filter has an infrared cut filter, which cuts infrared components, and moiré and false colors of solid-state image sensors. A "low-pass filter" for avoiding the phenomenon is included.

[0004] In such a digital camera, the mechanism by which such an optical filter is actually mounted will be described with reference to FIGS. FIG. 4 is a cross-sectional view of a digital camera as a conventional example, and FIG. 5 is a cross-sectional view of an optical filter, an image sensor, and a member for holding these components in the digital camera. FIG. 6 is an exploded perspective view of FIG. 7A is an enlarged view of a member holding the filter of FIG. 6, and FIG. 7B is a perspective view of FIG. 7A viewed from the opposite side.

In FIGS. 4 to 7, reference numeral 50 denotes one of members constituting a shutter unit, and a shutter base plate which most affects the shape of a filter holding member 51 described later. 5
An opening 0a has a bent shape 50b in the direction of a low-pass filter 52 described later, as shown in FIG. 5
1 is a filter holding member, 51a is a shutter base plate 5
A surface 51b opposite to the opening 51a on the shutter base plate 50 side is an abutting surface for restricting the position of a low-pass filter 52 described later in the optical axis direction.

Further, as shown in FIG. 5, when the low-pass filter 52 is incorporated in the filter holding member 51, the tapered surface 51c on the same side as the abutting surface 51b forms a triangular shape together with the peripheral edge (edge) 52a of the low-pass filter 52. A groove is formed. By applying an epoxy-based adhesive to these grooves, the low-pass filter 52 is fixed to the filter holding member 51, and also serves to prevent small dust such as dust from entering the gap between the filter holding member 51 and the low-pass filter 52. ing.

The groove 51d is provided with a foot 5 of a rubber member 54 described later.
4c is inserted to position the rubber member 54,
The rubber member 54 is prevented from easily shifting. 51e
Are provided with three screw holes 51f and two positioning dowels 51g for fixing the filter holding member 51 to a mounting member 55 described later (FIG. 7), and project from both sides of the filter holding member 51. It is a flange. 51h
Is a positioning portion that can determine the position of the filter holding member 51 in the optical axis direction by abutting the mounting member 55.

The low-pass filter 52 is made by laminating several plates made of a material such as silicon dioxide, and has the effect of optically reducing moire, false colors, and other phenomena that occur when photographing is performed using a solid-state image sensor. have. Reference numeral 53 denotes an image sensor unit. The image sensor package 53a for housing an image sensor such as a CCD or a CMOS, a hard board 53b dedicated to the image sensor, and a hard board 53b on which the image sensor package 53a is mounted are soldered to a positioning member 55 described later. It is composed of a plate-shaped fixing member 53c having four projecting portions for fixing.

The rubber member 54 is made of silicon rubber which is elastically deformed, and is compressed between the filter holding member 51 whose opening 51a is closed by the low-pass filter 52 and the surface glass of the image pickup device package 53a during assembly. It will be in the state that was done. This makes it possible to provide a closed space between the two, and thus plays a role in preventing dust and the like from adhering to the surface of the low-pass filter 52.
The rubber member 54 has an opening 54a, a sealing portion 54b which is elastically deformed by being pressed against the surface glass of the image pickup device package 53a, and a groove 51d of the filter holding member 51, which regulates the position of the rubber member 54 and easily filters. Holding member 51
And a foot portion 54c shaped so as not to come off.

The mounting member 55 includes a low-pass filter 52.
, A fixing member 53c to which a hard substrate 53b on which the image pickup device package 53a is mounted is fixed by soldering, and an image pickup device package 53.
All members of the rubber member 54 which are compressed and fixed between the surface glass of a and the low-pass filter 52 are held. Then, these members are screwed to the front plate 56 while being held. 55a is an opening through which a photographing light beam passes, 55b
Is a tapped hole in which a tap for fixing the filter holding member 51 to a screw is cut. Reference numeral 55c denotes two flange portions each having a hole for determining the position of the mounting member 55 with respect to the front plate 56 when the dowels protruding from the front plate 56 enter and a hole for fixing the mounting member 55 to the front plate 56 with screws. Reference numeral 55 d denotes four mounting portions fixed together with the bent portion of the fixing member 53 by soldering.

[0011]

However, in the above configuration, when the shutter base plate 50 is brought close to a position where it does not interfere with the low-pass filter 52 in order to reduce the size of the constituent units, the opening of the shutter unit, especially the shutter base plate 50, is reduced. Since the shape of the portion 50a is a bent shape 50b as shown in FIG. 5 on the low-pass filter 52 side,
Opening 51a of filter holding member 51 and shutter base plate 5
0 interferes.

In order to avoid such interference, if the size of the opening 51a of the filter holding member 51 is increased to a position where the opening 51a does not interfere with the shutter base plate 50, the size of the filter holding member 51 increases in that case. Accordingly, the size of the low-pass filter 52 also needs to be increased, which causes problems of cost increase and enlargement of the camera.

If the shutter base plate 50 is retracted in the direction of the optical axis to a position where the shutter base plate 50 does not interfere with the opening 51a of the filter holding member 51, the camera becomes thick because the shutter base plate 50 escapes in the direction in which the thickness of the camera increases. The problem occurs. Further, when performing the operation of sweeping out dust attached to the surface of the low-pass filter 52, if the shape near the opening of the filter holding member 51 is as shown in FIG. 5, the corner of the filter holding member 51 (FIG. It becomes difficult to sweep out the garbage and the like collected in the above), and it is necessary to take measures against this problem.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a filter holding mechanism which can solve the problems of cost increase and enlargement of a camera, and which is excellent in maintainability, and an image pickup apparatus having the same.

[0015]

According to the present invention, there is provided a filter holding mechanism for holding an optical filter on a photographing optical path via a filter holding member, wherein the filter holding member includes an optical filter. An opening for fitting and holding is formed, and a flat portion formed around the opening edge along a predetermined direction of the opening and / or a slope connected to the flat portion and expanding along the optical axis direction. It has a surface portion.

Further, in the filter holding mechanism of the present invention, the flat portion is set at the same height or lower in the optical axis direction with respect to the surface of the optical filter, and is provided between the flat surface portion and the inclined surface portion. The angle that can be formed is an obtuse angle.

Further, in the filter holding mechanism of the present invention, the flat portion and the inclined surface portion are formed along a first direction of the optical filter and the opening.

Further, the filter holding mechanism of the present invention is characterized in that the filter holding mechanism has a position regulating portion for regulating the position of the optical filter in the optical axis direction along a second direction other than the first direction. .

Further, in the filter holding mechanism according to the present invention, the position restricting portion is configured to overlap in the optical axis direction so that the optical filter abuts.

Further, in the filter holding mechanism according to the present invention, the filter holding member is arranged adjacent to a shutter unit, and the inclined surface is arranged inside an opening of the shutter unit.

According to another aspect of the present invention, there is provided an image pickup apparatus comprising: an optical unit for optically forming an image of an object; an image pickup unit for converting an optical object image formed by the optical unit into an electric signal; An image pickup apparatus comprising: a recording unit that records an image signal of a captured subject; and a display unit that displays a captured image, wherein any one of the above-described units is provided on an imaging optical path between the optical unit and the imaging unit. And a filter holding mechanism.

According to this configuration, it is possible to solve the problems such as enlargement and cost increase of the digital camera, which is the cause of the low-pass filter, and to easily sweep out dust attached to the low-pass filter, even though the holding member has the same configuration as the conventional one. A holding member can be realized.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view of the single-lens reflex digital camera according to the present embodiment as viewed from above, and FIG. 2 is a view of the digital camera as viewed from the back.
1 and 2, reference numeral 1 denotes a camera body, and reference numeral 2 denotes an eyepiece window for finder observation. Reference numeral 3 denotes an AE (auto exposure) lock button, and reference numeral 4 denotes an AF (auto focus) distance measuring point selection button. 5
Reference numeral 6 denotes a release button for performing a shooting operation. Reference numeral 6 denotes a main electronic dial for inputting a multi-function signal for inputting a numerical value to the camera and switching a shooting mode in combination with other operation buttons. 7 is shooting mode and shutter time,
This is a top display panel on which numerical values required for shooting, such as the aperture and the number of shots, are displayed. 8 is a shooting mode selection button, 9
Denotes an AF mode selection button, and 10 denotes a photometry mode selection button, which also serves as a light control correction button.

Reference numeral 11 denotes a sub electronic dial for selecting photographing conditions of the digital camera having the same functions as the main electronic dial 6. A dial lock switch 12 locks an input function of the sub electronic dial 11.
A main switch 13 prohibits all operations of the digital camera. 14 is for storing a PC card.
PC cover covering two throttles. Reference numeral 15 denotes an interchangeable photographing lens including a plurality of objective lenses.

Next, how the optical filter is mounted on the digital camera in the embodiment of the present invention will be described with reference to FIG. FIG. 3 is a sectional view showing a mechanism for holding the optical filter according to the present embodiment.
Since the optical filter, the mechanism for holding the image sensor, and the components are substantially the same as those in the conventional example (FIG. 5), the filter holding member 16 will be particularly described here.

In FIG. 3, the filter holding member 16 is
An opening for fitting and holding the low-pass filter 17 is provided, and a flat portion 16a formed around an opening edge of the opening on the shutter unit side is connected to the flat portion 16a so as to expand toward the shutter unit. And a tapered surface (inclined surface portion) 16b is formed.

The flat portion 16a on the shutter unit side is set to the same height or lower in the optical axis direction as the surface 17a of the low-pass filter 17. Also, the flat portion 16
Since the angle formed between the tapered surface 16b and the tapered surface 16b is an obtuse angle, the dust collected on the corner can be easily and accurately taken out when the dust on the surface 17a of the low-pass filter 17 is swept and cleaned. it can.

However, the position of the low-pass filter 17 in the optical axis direction cannot be restricted only by such a shape. Here, the low-pass filter 17 is formed in a rectangular shape, but two sides (first direction) of the four sides of the filter holding member 16 surrounding the low-pass filter 17 have a shape as shown in FIG. The remaining two sides (second direction) are substantially the same as the shape shown in FIG. That is, it is a position restricting portion that overlaps in the optical axis direction such that the low-pass filter 17 abuts, like the abutting surface 51b shown in part A in FIG. The position of the low-pass filter 17 in the optical axis direction can be regulated by the position regulating section.

Further, the shape shown in FIG. 3 is a bent portion 18a protruding toward the low-pass filter 17 of the shutter base plate 18.
Has an angle to escape well with the tapered surface 16b,
The tapered surface 16b is arranged inside the opening of the shutter unit. As a result, the shutter unit including the shutter base plate 18 can be made closer to the low-pass filter 17 side, and the thickness of the entire component in the optical axis direction can be reduced. Further, it is not necessary to enlarge the opening of the filter holding member 17 to escape the bent portion 18a of the shutter base plate 18. As a result, it is not necessary to increase the size of the low-pass filter 17, and problems such as an increase in the size of the camera and an increase in cost can be completely solved.

[0030]

As described above, according to the present invention, in the optical filter holding mechanism of this kind of digital camera, it is possible to solve problems such as an increase in cost and an increase in size of the digital camera due to the optical filter. At the same time, it is possible to provide a holding member that easily sweeps out dust attached to the optical filter, and therefore, it is possible to realize a substantially inexpensive imaging device with excellent maintainability.

[Brief description of the drawings]

FIG. 1 is a top view of a single-lens reflex digital camera according to an embodiment of the present invention.

FIG. 2 is a view of the digital camera according to the embodiment of the present invention as viewed from the back.

FIG. 3 is a cross-sectional view illustrating a mechanism for holding an optical filter according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view of a conventional digital camera.

FIG. 5 shows an optical filter in a conventional digital camera;
FIG. 3 is a cross-sectional view of an imaging element and a member that holds the imaging element.

FIG. 6 is an exploded perspective view of a member shown in FIG. 5 in a conventional example.

7A is an enlarged view of the filter holding member of FIG. 6,
(B) is the perspective view which looked at (a) from the opposite side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Camera main body 2 Eyepiece window 3 AE (auto exposure) lock button 4 AF point selection button 5 Release button 6 Main electronic dial 7 Top display panel 8 Shooting mode selection button 9 AF mode selection button 10 Photometry mode selection button 11 Sub electronic Dial 12 Dial lock switch 13 Main switch 14 PC cover 15 Shooting lens 16 Filter holding member 17 Low pass filter 18 Shutter base plate

Claims (7)

[Claims] 1. A filter holding mechanism for holding an optical filter on an imaging optical path via a filter holding member, wherein the filter holding member has an opening for fitting and holding the optical filter, A filter holding mechanism having a flat portion formed around the opening edge along a predetermined direction of the opening portion and / or an inclined surface portion connected to the flat portion and expanding along the optical axis direction. 2. The flat portion is set at the same height or lower in the optical axis direction with respect to the surface of the optical filter, and an angle formed between the flat portion and the inclined surface portion connected to the flat portion is an obtuse angle. The filter holding mechanism according to claim 1, wherein: 3. The filter holding mechanism according to claim 1, wherein the flat portion and the inclined surface portion are formed along a first direction of the optical filter and the opening. Filter holding mechanism. 4. The filter holding device according to claim 3, further comprising a position regulating portion that regulates a position of the optical filter in an optical axis direction along a second direction other than the first direction. mechanism. 5. The filter holding mechanism according to claim 4, wherein the position restricting portion is configured to overlap in the optical axis direction such that the optical filter abuts. 6. The filter holding member according to claim 1, wherein the filter holding member is disposed adjacent to a shutter unit, and the inclined surface is disposed inside an opening of the shutter unit. Item 7. A filter holding mechanism according to Item 1. 7. An optical unit for optically forming an image of a subject, an imaging unit for converting an optical subject image created by the optical unit into an electric signal, and an image signal of the subject taken by the imaging unit. 7. An image pickup apparatus comprising: a recording unit for recording; and a display unit for displaying a photographed image, wherein the photographing optical path is provided between the optical unit and the image pickup unit. An imaging apparatus comprising the filter holding mechanism according to any one of claims 1 to 3.