JP2001042380A - Photographing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain miniaturization of a photographing device and simplification of a mechanism by providing an optical filter in the vicinity of a position at which it is converged most at the inside of an optical path covering a necessary viewing angle on an image formation surface. SOLUTION: An aperture 1 to regulate the necessary viewing angle and to shield light is provided on an image formation surface 2, and a first group lens 3, a filter 4 and a second group lens 5 are arrayed by having an optical axis L of a lens as the axis. When the first group lens 3 and the second group lens 5 are both brought close to the image formation surface in a constitution thereof, a necessary optical path size at the inside of an optical system is expanded by the optical path in which an image is formed at a C point and the D point of the necessary peripheral viewing angle separated from an optical axis center point A. In this case, it is only R2 of a back end part of the first group lens 3 whose necessary optical path radius is reduced by movement of the lens from a telephoto side to the wide angle side, and it is the minimum part of the optical system optical path necessary size. Thus, the filter 4 is arranged at this position or in the vicinity of the position, so that the necessary viewing angle is totally covered by the minimum filter size. The filter size is reduced, so that the miniaturization of a device is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographing apparatus having a filter, and more particularly, to a photographing apparatus capable of reducing the size and simplification of the mechanism, easily changing the filter effect, and contributing to cost reduction. It is what we aim for.

[0002]

2. Description of the Related Art One of the techniques for taking a photograph has a filter effect. One of the filters is a polarization filter. The one-way polarization filter has the effect of passing only the light that matches the polarization direction of the incident light. By adjusting the polarization direction in accordance with the incident light using the imaging optical system, there is an effect of removing irregular reflection and glare of the subject. Several devices have been disclosed for providing a polarizing effect to a captured image by providing a polarizing filter in a capturing optical path. JP Hei 10
JP-A-319474, JP-A-8-262411 and JP-A-10-90748.

In Japanese Patent Application Laid-Open No. 10-319474, a manually rotatable polarizing filter unit is attached to the tip of a taking lens barrel in a taking optical path, and a polarizing filter is rotated coaxially with a taking optical axis to provide a polarizing effect on a taken image. To bring. In Japanese Patent Application Laid-Open No. H8-26211, a disk-shaped polarizing plate that rotates substantially coaxially with the photographing optical axis is arranged within the photographing optical axis, and the outer periphery of the polarizing plate is rotated by a polarizing plate rotating means to rotate the polarizing plate into a photographed image. It has an effect. In Japanese Patent Application Laid-Open No. Hei 10-90748, a plurality of openings having a diameter substantially equal to the diameter of a photographing optical path are provided in a turret having a rotation center at a position eccentric from a photographing optical axis, and a polarizing filter is provided in a part of the openings. By rotating the turret, a polarization effect on a captured image is provided.

[0004]

However, in Japanese Patent Application Laid-Open No. Hei 10-319474, it is inconvenient to remove the polarization filter unit when it is desired to eliminate the polarization effect. Also, in Japanese Patent Application Laid-Open No. 8-26211, since the polarizing plate is always present in the photographing optical path, when it is desired to eliminate the polarizing effect, the polarizing plate and the polarizing plate driving means are moved to move the polarizing plate out of the optical path. Had to be done. For this reason, two mechanisms, a mechanism for rotating the polarizing plate about the optical axis and a mechanism for moving the polarizing plate toward and away from the optical axis, are required, and the mechanism has been complicated. Also, in JP-A-10-90748,
By providing one polarization filter with one polarization direction at a part of the opening that is almost equal to the optical path diameter of the turret,
Although it can cope with the polarization angle in one direction, the polarization effect cannot be changed because there is no means for changing the angle of the polarizing filter with respect to the optical axis in the imaging optical path.

Further, in all of the conventional examples, when the lens configuration of the condensing optical system becomes complicated, the converging optical path of the optical axis center light and the converging light path of the peripheral light (determined by the required angle of view on the image plane) are required. The required optical path diameter determined by one optical path varies greatly depending on the location in the optical path. This also changes even when the optical system changes magnification. In other words, depending on the position where the filter is provided, a large filter is used at a place where the optical path diameter is large,
For this reason, the required diameter of the filter has been increased and the photographing apparatus has been increased in size. Further, in Japanese Patent Application Laid-Open No. H10-90748, in which the filter can be replaced inside the apparatus, the number of filters on the turret is limited by increasing the required diameter of the filter, or the turret is enlarged, resulting in insufficient function. The device was too large. Further, when a filter is inserted into the photographing optical system, the amount of light incident through the photographing optical system differs from the case where there is no filter. That is, there is a problem in that an exposure (shutter speed and aperture value) calculated from an incident light amount from a photometric optical system that does not use a filter, which is different from an imaging optical system that uses a filter, does not provide an appropriate exposure. Was.

Accordingly, the present invention provides an image pickup apparatus which solves the above-mentioned problems in the conventional apparatus, can reduce the size and simplify the mechanism, can easily change the filter effect, and can contribute to cost reduction. The purpose is to do so.

[0007]

According to the present invention, in order to solve the above-mentioned problems, a prism optical system includes the following (1) to (1).
0). (1) An imaging apparatus according to the present invention, wherein an optical filter is arranged in an optical path of a condensing optical system having at least one lens, wherein the optical filter covers an required angle of view on an imaging plane. Is located near the most narrowed position. (2) In the photographing apparatus of the present invention, the optical filter is provided on a rotatable optical filter support member having a rotation center at a position decentered from the optical axis of the optical path, and sets a required angle of view on the image plane. It is characterized in that it can be arranged near the most narrowed position in the optical path to be covered. (3) The imaging device according to the present invention is characterized in that the optical filter is a polarizing filter having a polarization characteristic in one direction, an ND filter for reducing the amount of incident light, or a color filter. (4) The imaging apparatus of the present invention includes an optical filter support member having a rotation center at a position decentered from the optical axis of the optical path in a light path of a condensing optical system having at least one lens,
The optical filter support member is provided with a polarization filter having a polarization characteristic in one direction, and has a configuration in which a rotation angle of the support member makes a polarization angle with respect to an optical axis variable. (5) The imaging device according to the present invention is characterized in that the polarizing filter is constituted by a plurality of polarizing filters. (6) The photographing apparatus of the present invention is characterized in that the polarizing filter is constituted by one polarizing filter. (7) The imaging device of the present invention is characterized in that the polarizing filter is provided on the filter support member so as to cover an imaging optical path within 180 degrees of the rotation angle of the filter support member. (8) The photographing apparatus of the present invention is characterized in that a filter other than the polarizing filter is provided in a region of the filter supporting member where the polarizing filter is not provided, or a portion having no polarizing filter effect is formed. (9) The imaging apparatus according to the present invention, wherein the polarizing filter or a filter other than the polarizing filter or a portion having no polarizing filter effect covers the required angle of view on an image plane in the light path of the condensing optical system. It is characterized in that it can be arranged in the vicinity of the most narrowed position of the inside. (10) The photographing apparatus of the present invention is characterized in that the condensing optical system is a photographing optical system or a photometric optical system.

[0008]

Next, an embodiment of the present invention will be described. By configuring as in the above (1) and (9), even in a system in which the lens configuration of the focusing optical system such as the variable power optical system is complicated, the optical axis center light focusing optical path and the peripheral light focusing optical path can be used. A filter can be provided at or near the position where the required optical path diameter determined by the two optical paths is the smallest, and the required diameter of the filter can be reduced and the imaging device can be reduced in size. Further, by configuring as described in (2) and (3) above, for example, even when a turret having a filter as disclosed in Japanese Patent Application Laid-Open No. H10-90748 is used, the required diameter of the filter can be reduced. Therefore, even when the number of filters on the turret increases, the turret can be downsized, and the entire apparatus can be downsized. Further, by configuring as in the above (4) and (5), it becomes possible to rotate a plurality of polarization filters by the filter holding member without providing a complicated mechanism, and it becomes easy to change the polarization effect. In addition, by configuring as described in (6) above, a desired polarization angle can be selected by rotating one polarization filter eccentrically with respect to the optical axis by utilizing the characteristic of one polarization direction of the polarization filter. become. Also, the assembly is easy and the parts manufacturing cost is low. In the configuration (5), a dedicated polarization filter must be used to change the polarization direction by one, and the number of filters increases. However, in the configuration (6), depending on the number of required polarization positions, a filter holding member may be required. The size is reduced, and the polarization can be adjusted steplessly. In addition, with the configuration as described in (7) above, one polarizing filter is disposed at a portion within a rotation angle of 180 degrees at the maximum of the filter holding member, and the size of the filter holding member can be reduced. Can be. This is because if a polarization filter having one-way polarization is used, it is theoretically sufficient to have a polarization change of 180 degrees to obtain all polarization characteristics. In addition, with the configuration as described in (8) above, the remaining rotating part of the filter holding member other than the polarization filter can be effectively used for the filter effect other than the polarization filter and the cancellation of the filter effect. In addition, with the configuration as described in (10) above, not only the photographing optical system but also the photometric optical system can obtain the effect of using the filter mechanism, and can obtain the light metering information in consideration of the incident light amount change by the filter. Appropriate exposure information can be calculated.

[0009]

Embodiments of the present invention will be described below. [First Embodiment] FIG. 1 is a diagram showing a configuration of a first embodiment of the present invention. FIG. 1A is a perspective view of the configuration of the present embodiment. L
Reference numeral 1 denotes an optical axis of the lens, and reference numeral 1 denotes an aperture for defining a required angle of view on the image plane 2 and shielding light. A on the image forming plane 2 is a center point of the optical axis, B is a short side position on a vertical line from the optical axis, C is a long side position in a horizontal direction from the optical axis, and D is a required angle of view diagonal position. I have. AB, AC, and AD are equal in distance. 3 is a first group lens, 4 is a filter,
Reference numeral 5 denotes a second group lens, which is arranged around the optical axis L. Incidentally, the first group lens 3, the second group lens 5, the filter, and the like are movably held by driving means (not shown), but the description of the holding configuration and the driving method is omitted.

FIG. 1B is a sectional view showing a telephoto position state of the present embodiment. As shown in the figure, when the required angle of view on the image plane 2 is relatively large with respect to the lens diameter, the spread of the image forming optical paths of the peripheral portions B, C, and D of the required angle of view in the optical system cannot be ignored. . R1 and R2 represent the optical path radii before and after the first group lens 3, and R3 and R4 represent the optical path radii before and after the second group lens 3. At the telephoto position, the required optical path radii R2, R
3 is the minimum, but there is not much difference in the length of R1, R2, R3, and R4 as a whole. FIG. 1C is a cross-sectional view illustrating a wide-angle position state of the present embodiment. 1 group lens 3, 2
When the group lenses 5 both approach the imaging plane, the optical paths that form images at points C and D of the required peripheral angle of view that are distant from the optical axis point A increase the required optical path diameter in the optical system. Due to the movement of the lens from telephoto to wide-angle, the required optical path radius is reduced only at the rear end R2 of the first lens unit. Therefore, the rear end of this first group is shown in FIG.
And the filter 4 is arranged at this position or in the vicinity of this position, so that the entire required angle of view can be covered with the smallest filter diameter. In FIG. 1, a variable focus lens is disclosed as an example, but a fixed focus may be used. There is no problem even if it is used for a photographing optical system or a photometric optical system.

[Embodiment 2] FIG. 2 is a diagram showing the configuration of Embodiment 2 of the present invention. In FIG. 2, reference numeral 6 denotes a shutter unit, which changes an optical path of the photographing optical system from a closed state to an open state for a predetermined time by controlling exposure time from a microcomputer. Reference numeral 3 denotes a first-group lens of the photographing optical system, 5 denotes a second-group lens, 7 denotes a filter holding means having a filter described later and having a center of rotation at a position decentered from the photographing optical axis, and the end face 7a is manually moved from outside the camera. Alternatively, the position is determined by the elastic locking member 8 by being rotated using the driving means and locked. Reference numeral 9 denotes a motor for driving the photographing optical system to a predetermined position, which is controlled by the microcomputer 11. Reference numeral 10 denotes a photographing film feeding motor, which is controlled by the microcomputer 11 by a cartridge spool driving gear 12 and a film feeding means (not shown) to drive the film to a predetermined position. 1
Reference numeral 4 denotes a photographing apparatus main body, 14a denotes a cartridge chamber, and 14b denotes a film winding chamber. Reference numeral 15 denotes a photographing device, reference numeral 19 denotes a photometric optical system lens, a filter holding member 7 is provided, and a photometric element 13 is disposed at an image forming position of the photometric optical system.
The photometric information is transmitted to the microcomputer 11.

FIG. 3 is an exploded detailed view of the filter holding member 7 in this embodiment. FIG. 3A is a diagram using a plurality of unidirectional polarization filters. The center of rotation M of the filter holding member 7 is located at a position eccentric to the optical axis L in parallel. The filter holding member 7 has a structure in which two upper and lower sheets are laminated, and is positioned by a dowel 7f. A finger hook 7a is carved at the end of the upper plate so that the user can freely rotate the finger. In the figure, it is rotated by a finger, but it is needless to say that it may be driven by a power source such as a motor and a gear. The lower plate is provided with a concave portion 7g for determining the rotational position at each stop position, and the filter holding member is positioned by the locking of the elastic locking member 8. While the filter holding member 7 is rotating, the elastic locking member is retracted because it is elastically pressed against the holding member 7. The upper plate is provided with five openings 7d around the rotation axis, and similarly, the lower plate is also provided with five openings 7e so as to be coaxial with the openings 7d of the upper plate. In the figure, the center of the indexing position opening closest to the elastic locking member 8 is the optical system optical axis L. Numeral 16 denotes a polarization filter having one polarization direction. The positioning filter 16 is fitted with a positioning portion 16a so that the positioning direction of the lower plate is not changed.
Is assembled. In the embodiment, the number is three, but if the number is two or more, the polarization direction can be changed. Reference numeral 17 denotes a color filter or ND filter other than the polarization filter, and one of the openings 7e has no filter at all. By providing a filter other than the polarization filter in a portion of the filter holding member other than the rotation angle used by the polarization filter, or by providing a portion having no filter effect, the rotation area of the filter holding means is effectively used.

In the configuration shown in FIG. 3A, only by rotating the filter holding means 7, the polarization effect can be changed, the filter effect processing other than the polarization filter can be performed, and the filter effect can be deleted. However, when the number of polarizing filters increases, a subtle polarization variable effect can be obtained, but the number of polarizing filters increases, which increases assembly and cost. FIG. 3 (b) shows the split polarizing filter 16 of FIG. 3 (a) as an integral one-way polarizing filter 18, and the positioning portion 18a is fitted with the positioning plate 7c of the lower plate. On the other hand, one is assembled so that the polarization direction does not change. Three of the openings 7d are arranged so as to be polarizing filters.
The integration of the polarizing filter facilitates assembly and reduces parts and assembly costs. The filter function is the same as that of FIG.

FIG. 3 (c) shows a part of the opening of the filter holding member 7 as an elongated hole 7i centered on the rotation axis M as shown in the figure, and a concave portion 7g for indexing the position of the filter holding member.
The corresponding portion of the long hole 7i is formed as a continuous concave portion 7h so that the portion can be stopped at an arbitrary position in the polarization filter region. As shown in the figure, the polarization filter 18 has a filter holding member rotation angle of 18 degrees.
It is a size that covers within 0 degrees. This is because if a polarization filter having one-way polarization is used, it is theoretically sufficient to have a polarization change of 180 degrees to obtain all polarization characteristics. The size of the filter holding member can be reduced by arranging one polarizing filter in a portion within a rotation angle of 180 degrees at the maximum of the filter holding member. Further, the remaining rotating portion of the filter holding member 7 other than the polarization filter is effectively used for the filter 17 other than the polarization filter and the void having no filter effect. In the second embodiment, the filter holding member shown in FIG. 3 is used for both the photographing optical system and the photometric optical system. Therefore, not only the photographing optical system but also the photometric optical system can obtain the effect of using the filter mechanism, and the microcomputer 11 calculates appropriate exposure information from the photometric information in consideration of the change in the incident light amount by the filter. The shutter opening drive is performed at the set exposure value, and the exposure is properly performed on the photographic film on the image forming plane 2 (not shown).

FIG. 4 shows several states in which the filter holding member 7 shown in FIG. 3A or 3B is rotated. It can be seen that the polarization angle with respect to the optical axis L changes by changing the stop position of the filter holding member in (a), (b), and (c). In addition to (a), (b), and (c), the filter can be rotated and held at a filter 16 other than the polarization filter or at a position where there is no filter effect. FIG. 5 shows several states in which the filter holding member 7 shown in FIG. 3C is rotated.
It can be seen that the polarization angle with respect to the optical axis L changes by changing the stop position of the filter holding member in (a), (b), and (c). Needless to say, the polarization effect can be finely changed at any position other than (a), (b), and (c) where the elastic locking member 8 can be locked with the concave portion 7h. In addition to (a), (b), and (c), the filter can be rotated and held at a filter 16 other than the polarization filter or at a position where there is no filter effect. In the above embodiment, the required angle of view 1 is, for example, the aperture size determined by the standard of the silver halide photographic film, but may be arbitrarily determined according to the difference in the standard. The image forming surface 2 is, for example, a silver halide photographic film emulsion surface or a light receiving surface of a photometric element, but may be a light receiving sensor surface such as a CCD or an artificial retinal chip.

[0016]

As described above, according to the present invention, by adopting a configuration in which the optical filter is disposed near the most narrowed position in the optical path covering the required angle of view on the image forming plane, Since the size of the system can be reduced, restrictions on the size in mechanism design are reduced, the degree of freedom in design is improved, and the size and cost of the imaging apparatus can be reduced. According to the present invention, a complicated mechanism is eliminated by providing a polarizing filter having a polarization characteristic in one direction on an optical filter support member and adopting a configuration in which a polarization angle with respect to an optical axis is variable by rotation of the support member. This makes it easy to change the polarization effect, and it is possible to convert the filter to another filter or to remove the filter effect, thereby contributing to simplification of the mechanism and cost reduction. It will be easier.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment according to the present invention;
(A) is a perspective view of the configuration, (b) is a sectional view showing a telephoto position state, and (c) is a sectional view showing a wide-angle position state.

FIG. 2 is a perspective view of a photographing apparatus according to a second embodiment of the present invention.

FIG. 3 is an exploded view of a filter holding member according to a second embodiment of the present invention.

FIG. 4 is a diagram illustrating several states in which a filter holding member is rotated according to a second embodiment of the present invention.

FIG. 5 is a diagram illustrating several states in which a filter holding member is rotated according to a second embodiment of the present invention.

[Explanation of symbols]

 1: Required field angle 2: Image plane 3: 1 group lens 4: Filter 5: 2 group lens 6: Shutter unit 7: Filter holding member 8: Elastic locking member 9: Lens driving motor 10: Film feeding motor 11: microcomputer 12: cartridge spool drive gear 13: photometric element 14: main body 15: photographing device 16: one-way polarizing filter 17: filter 18: one-way polarizing filter 19: photometric optical system lens L: optical axis M: filter holding member Rotation center axis

Claims (10)

[Claims] 1. An imaging apparatus in which an optical filter is disposed in an optical path of a condensing optical system having at least one lens, wherein the optical filter is the most narrowed in the optical path covering a required angle of view on an imaging plane. An imaging device, which is arranged near a position. 2. The optical filter according to claim 1, wherein said optical filter is provided on a rotatable optical filter support member having a center of rotation at a position decentered from an optical axis of said optical path. The photographing apparatus according to claim 1, wherein the photographing apparatus is configured to be able to be arranged near the most narrowed position. 3. The optical filter according to claim 1, wherein the optical filter is a polarizing filter having a polarization characteristic in one direction, an ND filter for reducing the amount of incident light, or a color filter. Shooting equipment. 4. An optical filter supporting member having a rotation center at a position decentered from an optical axis of the optical path in a light path of a condensing optical system having at least one lens, wherein the optical filter supporting member has one-way polarized light. An imaging apparatus comprising: a polarizing filter having characteristics; and a configuration in which a polarization angle with respect to an optical axis is variable by rotation of the support member. 5. The photographing apparatus according to claim 4, wherein said polarizing filter comprises a plurality of polarizing filters. 6. The photographing apparatus according to claim 4, wherein said polarizing filter is constituted by one polarizing filter. 7. The filter support member according to claim 4, wherein the polarizing filter is provided on the filter support member so as to cover an imaging optical path within 180 degrees of a rotation angle of the filter support member. The photographing device according to the item. 8. The filter supporting member according to claim 4, wherein a filter other than the polarizing filter is provided in a region where the polarizing filter is not provided, or a portion having no polarizing filter effect is formed. The imaging device according to claim 1. 9. The polarizing filter or a filter other than the polarizing filter or a portion having no polarizing filter effect is most narrowed down in the optical path covering the required angle of view on an image plane in the optical path of the condensing optical system. The photographing apparatus according to claim 8, wherein the photographing apparatus is configured to be able to be arranged in the vicinity of a position where the photographing is performed. 10. The photographing apparatus according to claim 1, wherein the light condensing optical system is a photographing optical system or a photometric optical system.