JP2011002531A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera which can cope with stray light.SOLUTION: The camera includes a mirror unit 30 capable of moving between in a mirror-up state where the mirror unit retreats from a photographing optical path and in a mirror-down state where it is arranged in the photographing optical path. The mirror unit 30 includes: a mirror 31 which reflects and guides subject light to a finder in the mirror-down state; a main mirror holding frame 33 which holds the mirror 31, and where a fitting part having a step part extending perpendicularly to an optical axis and formed to be hollowed from a front surface side thereof on which the subject light is made incident in the mirror-down state, and a through-hole extending adjacently to the step part, is formed; and a light shielding member 50 which is fit to the fitting part and has a protrusion piercing through the through-hole to protrude from a back surface side of the main mirror holding frame 33 and an engagement part engaged with the step part.

Description

  The present invention relates to a camera including a mirror unit that is movable between a mirror-up state that is retracted from a photographing optical path and a mirror-down state that is disposed in the photographing optical path.

  In some cases, light (so-called stray light) reflected by a photographing lens or a member inside the camera enters the imaging unit. In order to prevent such stray light, various measures against stray light are taken in the mirror unit or in the vicinity thereof (for example, see Patent Document 1).

JP 2000-98469 A

  An object of the present invention is to provide a camera with a further countermeasure against stray light.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.

The invention described in claim 1 includes a mirror unit (30) movable between a mirror-up state retracted from the photographing optical path and a mirror-down state disposed in the photographing optical path, and the mirror unit (30 ) Reflects the subject light in the mirror-down state and guides it to the finder, holds the mirror (31), extends in a direction perpendicular to the optical axis, and enters the subject light in the mirror-down state. A mirror holding frame (33) in which a fitting portion having a step portion (37) formed to be recessed from the surface side to be formed and a through hole (38) extending adjacent to the step portion (37) is formed; Engaged with the fitting portion, the projection (51) projecting from the back surface side of the mirror holding frame (33) through the through hole (38), and the stepped portion (37). Joint part (52), A light blocking member having (50), a camera (1), characterized in that it comprises a.
The invention according to claim 2 includes a mirror unit (30) movable between a mirror-up state retracted from the photographing optical path and a mirror-down state disposed in the photographing optical path, and the mirror unit (30 ) Holds the mirror (31) that reflects the subject light to the finder in the mirror-down state and the mirror (31), and extends perpendicularly to the optical axis on the back surface on the photographing optical path side in the photographing state. A mirror holding frame (233) in which a groove (238) is formed, an insertion part (252) inserted into the groove (238), a protrusion (251) protruding from the back surface of the mirror holding frame (233), A camera (1) comprising a light shielding member (250) having
A third aspect of the present invention is the camera (1) according to the first or second aspect, wherein the light shielding member (50, 250) is a foam member. is there.
A fourth aspect of the present invention is the camera (1) according to the first or second aspect, wherein the light shielding member (50, 250) is made of metal and is subjected to antireflection processing. Camera (1).
Note that the configuration described with reference numerals may be modified as appropriate, and at least a part of the configuration may be replaced with another component.

  ADVANTAGE OF THE INVENTION According to this invention, the camera in which the countermeasure against the further stray light was given can be provided.

It is sectional drawing of the mirror down state of the camera to which 1st Embodiment of this invention is applied. It is sectional drawing of the mirror up state of the camera to which 1st Embodiment of this invention is applied. It is a figure which shows the main mirror holding frame and the light shielding member fitted to the main mirror holding frame. It is the elements on larger scale of FIG. 2, and is a figure which shows the scattering of stray light. It is a figure which shows the comparison form of 1st Embodiment. It is a figure which shows 2nd Embodiment of this invention.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings and the like. FIG. 1 is a cross-sectional view of a camera 10 to which the first embodiment of the present invention is applied, and shows a case where a mirror unit 30 is in a mirror-down state (observation state) arranged in a photographing optical path. FIG. 2 shows a case in which the mirror unit 30 is in the mirror-up state (retracted state) retracted from the imaging optical path in the camera 10.

  In the following drawings, an orthogonal coordinate system is provided as appropriate for ease of explanation and understanding. In this coordinate system, the direction toward the left side as viewed from the photographer at the position of the camera 10 when the photographer shoots a horizontally long image with the optical axis A horizontal (hereinafter referred to as a normal photographing position) is the X axis plus direction. And Also, the upward direction at the normal shooting position is the Y-axis plus direction, and the direction toward the subject at the normal shooting position is the Z-axis plus direction.

  The camera 10 is a digital single-lens reflex camera, and includes a camera main body unit 11, a liquid crystal monitor 12, a mount unit 20, a mirror unit 30, a finder unit 40, a distance measuring sensor unit 60, a shutter unit 70, and an imaging unit 80.

  The camera body 11 is a main frame to which each part of the camera 10 is fixed, and a mount 20 is provided on an end surface on the subject side. A lens barrel (not shown) having a photographing lens, an aperture unit, and the like is detachably mounted on the mount unit 20.

  The liquid crystal monitor 12 is provided on the back surface of the camera body 11 and is configured by a liquid crystal display that displays information related to operations in addition to still images and live view images captured by the imaging unit 80.

  The mirror unit 30 includes a main mirror 31, a sub mirror 32, and a mirror driving unit (not shown). The main mirror 31 and the sub mirror 32 are held at fixed positions except during shooting, and are configured to rotate in a predetermined direction during shooting. The mirror unit 30 is provided at a position where subject light that has passed through a lens barrel (not shown) attached to the mount unit 20 is incident, and has a function of causing the subject light to enter the finder unit 40 or the shutter unit 70 and the imaging unit 80. It has.

  The main mirror 31 is a reflecting material that reflects subject light to the finder unit 40 and is held by a main mirror holding frame 33 described later. A semi-transmissive mirror having a characteristic of transmitting a part of light is used at the center of the main mirror 31. That is, the main mirror 31 transmits part of the subject light and makes the subject light incident on the sub mirror 32.

  The sub mirror 32 is a reflecting material that reflects part of the subject light transmitted through the main mirror 31 to the distance measuring sensor unit 60 and is held by a sub mirror holding frame (not shown). The sub mirror 32 is attached to the main mirror 31 so as to be rotatable. The sub mirror 32 is folded into the main mirror 31 and is raised on the back side of the main mirror 31 by the rotation.

  The main mirror 31 and the sub mirror 32 reflect subject light to the finder section 40 and the distance measuring sensor section 60 in the mirror down state shown in FIG. Of these, the photographer can observe the subject through the eyepiece unit 17 due to reflection on the finder unit 40.

  When a release button (not shown) is pressed for still image shooting, the main mirror 31 is rotated upward by the mirror driving unit described above to mirror up to the pentaprism 16 side, and the sub mirror 32 is interlocked therewith. Is also pivoted upward and folded so as to overlap the main mirror 31, and the mirror is raised as shown in FIG.

  As a result, the subject light is incident on the shutter unit 70 and the imaging unit 80 arranged on the rear side of the mirror unit 30 and can be photographed. Then, after the photographing is finished, the main mirror 31 and the sub mirror 32 are both rotated downward by the mirror driving unit and returned to the home position shown in FIG.

  The finder unit 40 includes a finder screen 15, a pentaprism 16, and an eyepiece unit 17. The finder screen 15 is an optical member disposed above the mirror unit 30, and an image is formed when the subject light reflected by the mirror unit 30 forms an image. The subject light on the finder screen 15 is guided to the eyepiece unit 17 by the pentaprism 16. As a result, the photographer can look through the viewfinder 18 and observe the image of the subject light.

  The pentaprism 16 is disposed above the finder screen 15 and is configured by a glass prism that emits an image of subject light imaged on the finder screen 15 to the eyepiece unit 17. The eyepiece unit 17 is an optical member disposed at a position where the subject light emitted from the pentaprism 16 is incident, and is a part that enlarges the image of the subject light to a predetermined magnification. The viewfinder 18 is an eyepiece optical system disposed on the rear side of the eyepiece unit 17 and is a portion that is photographed by a photographer.

  The ranging sensor unit 60 is a part that receives the subject light reflected by the sub-mirror 32 and detects the defocus amount of the subject light by a phase difference detection method, and includes a condensing lens, a separator lens, and a line sensor (not shown). It is configured. The distance measuring sensor unit 60 is fixedly disposed below the sub mirror 32.

  The shutter unit 70 is disposed behind the mirror unit 30, and subject light is incident when the main mirror 31 and the sub mirror 32 are mirrored up during photographing. The shutter unit 70 includes a plurality of shutter blades (not shown), and opens and closes the shutter blades in response to a shooting instruction by a release button or the like, so that subject light enters the imaging unit 80.

  The imaging unit 80 is an imaging unit that captures an image of subject light, and is provided at a position where the subject light that has passed through the shutter unit 70 enters. The imaging unit 80 includes a low-pass filter 81 and an imaging element 82. The image pickup element 82 is composed of a photodiode regularly arranged behind the low-pass filter 81, a CCD, a CMOS, or the like.

  When the photographer operates the release switch, the mirrors 31 and 32 in the mirror unit 30 swing and mirror up to the upper side of the optical path, so that the subject image light can reach the image pickup device 16B of the image pickup unit 80. Then, the shutter unit 70 opens for a predetermined time (exposure time), and the image sensor 16B is exposed to image light. The imaging unit 80 converts the image light into an electrical signal by the imaging element 16B, the image processing circuit performs image processing on the electrical image information, and displays the electrical image information as an image on the image display unit 12, and the captured image information is also displayed. Store in memory (ie, take a picture).

  Next, the main mirror holding frame 33 in the mirror unit 30 will be described. FIG. 3 is a view showing the main mirror holding frame 33 and the light shielding member 50 fitted to the main mirror holding frame 33. FIG. 3A is a perspective view of the light shielding member 50, and FIG. FIG. 3C is a partial perspective view of the mirror holding frame 33, and FIG. 3C is a partial perspective view showing a state where the light shielding member 50 is fitted in the main mirror holding frame 33.

  The main mirror holding frame 33 is a plastic molded product in this embodiment. As shown in FIG. 3B, the main mirror holding frame 33 has a rectangular shape, and holds the main mirror 31 on a surface (hereinafter referred to as a surface) 35 on which subject light is incident in the mirror-down state. A recess 36 is formed. The concave portion 36 is substantially the same shape as the main mirror 31 so as to hold the main mirror 31 without a gap, and has a rectangular shape in the present embodiment. Then, a step portion 37 formed so as to be recessed from the front surface 35 side toward the opposite surface (back surface) side from the front surface 35 side and extending in the X direction at the object-side front end portion of the recess 36 in the main mirror holding frame 33, and A fitting portion 39 having a through hole 38 extending adjacent to the stepped portion 37 is formed.

  The light shielding member 50 shown in FIG. 3A is an elongated member having an L-shaped cross section, and is made of a foaming member such as black sponge or rubber having a high light diffusion effect. Then, as shown in FIG. 3C, the light shielding member 50 protrudes from the back surface side of the main mirror holding frame 33 through the through hole 38 of the fitting portion 39 in a state where the light shielding member 50 is fitted in the fitting portion 39. A portion 51 and an engaging portion 52 that engages with the stepped portion 37.

  The light shielding member 50 is not limited to the foamed member as in the present embodiment. For example, it may be made of a metal material, and the tip 51a of the protrusion 51 may be further sharpened. Moreover, the antireflection effect becomes higher by performing antireflection coating, embossing, or flocking on the protruding portion 51.

  The light shielding member 50 is fitted into the fitting portion 39 from the surface 35 side of the main mirror holding frame 33 in the state of FIG. 3B in which the main mirror 31 is not held by the main mirror holding frame 33. At this time, the protruding portion 51 is inserted into the through hole 38 and the engaging portion 52 is arranged to engage with the stepped portion 37. Thereafter, the mirror is fitted into the recess 36.

As described above, this embodiment has the following effects.
(1) FIG. 4 is a partially enlarged view of FIG. 2 and shows stray light scattering. In the mirror-up state, light (stray light) incident from the photographing optical path collides with a light shielding member 50 provided at the tip of the mirror unit 30. Since the light shielding member 50 is made of a foam member, the scattering effect is high, stray light that is scattered and incident on the imaging unit 80 is reduced, and the occurrence of flare, ghost, and the like is reduced.

  FIG. 5 is a diagram showing a comparative form of the present embodiment. In the comparative form of FIG. 5, the main mirror holding frame 133 and the light shielding member 150 are manufactured integrally. As described above, when the main mirror holding frame 133 and the light shielding member 150 are manufactured integrally, if the foamed member is used, sufficient strength as the main mirror holding frame 133 cannot be secured. Moreover, if it manufactures with a metal material, cost will become high and will become heavy. Therefore, the production with the foamed member or the metal material is not preferable, and it is produced with the plastic material.

  However, in the case of manufacturing with plastic, injection molding or the like is common, but it becomes difficult to mold the tip 151a of the protrusion 151 of the light shielding member 50 to be sharp. For this reason, the stray light incident from the photographing optical system is not sufficiently scattered because the tip 151a of the protrusion 151 is not an acute angle and is not a foaming member, and the possibility that the stray light enters the imaging unit 80 is increased. Therefore, the effect of reducing the occurrence of flare and ghost in the imaging unit 80 is small.

  On the other hand, according to the present embodiment, since the main mirror holding frame 33 and the light shielding member 50 are separated and the main mirror holding frame 33 is manufactured by plastic molding, it is possible to ensure sufficient strength and to manufacture at a low cost. it can. And since the light-shielding member 50 was manufactured with the foaming member with a high light-shielding effect, or the metal material which has the acute protrusion 51, a high light-shielding effect can be acquired.

(2) Since the mirror unit 30 repeatedly moves and stops inside the camera 10, an impact is applied. When the light shielding member 50 and the main mirror holding frame 33 are separated, the adhesion may be peeled off due to the impact of movement and stop if the light shielding member 50 is simply adhered to the main mirror holding frame 33. However, in this embodiment, since the light shielding member 50 is inserted from the fitting portion 39 of the main mirror holding frame 33 and the main mirror 31 is further disposed thereon, the light shielding member 50 and the main mirror holding frame 33 are Is less likely to separate, and durability is improved.

(3) When the light shielding member 50 is made of a foam material, the main mirror 31 is arranged on the light shielding member 50 made of the foam material in the recess 36 of the main mirror holding frame 33. Therefore, a part of the impact applied to the main mirror 31 by the mirror up and mirror down can be absorbed by the light shielding member 50 made of the foam material, and the durability of the main mirror 31 is improved.

(Second Embodiment)
FIG. 6 is a diagram showing a second embodiment of the present invention. In the second embodiment, a groove 238 extending perpendicular to the optical axis is formed on the back surface of the main mirror holding frame 233. The light shielding member 250 can be slidably inserted into the groove 238. Since other shapes are the same as those in the first embodiment, the same reference numerals are given and description thereof is omitted.

  As shown in the drawing, a groove portion 238 having a T-shaped section from the back surface is formed on the subject side (Z plus side) of the main mirror holding frame 233. Although not shown, the groove 238 is open at one end of the main mirror holding frame 233 in the X direction. The light shielding member 250 includes an insertion portion 252 having a T-shaped cross section, and a protrusion 251 that protrudes from the back surface of the main mirror holding frame 233 while being held in the groove 238. The light shielding member 250 is slidably inserted from the opening end of the groove 238 in the main mirror holding frame 233 and is held by the main mirror holding frame 233.

  According to this embodiment, in addition to the effects of the first embodiment, the main mirror holding frame 233 is slidably inserted from the opening end of the groove 238 and is held by the main mirror holding frame 233. There is an effect that it is easy.

(Deformation)
The present invention is not limited to the above-described embodiment, and various modifications and changes as described below are possible, and these are also within the scope of the present invention.

(1) In the first embodiment, the light shielding member 50 has an L-shaped cross section. However, the present invention is not limited to this, and the light shielding member may be T-shaped. In this case, the fitting portion has an opening shape having a T-shaped cross section corresponding to the shape of the light shielding member and having stepped portions 37 formed on both sides thereof along the through hole. It may be.

(2) Moreover, also in 2nd Embodiment, the shape of the insertion part of a light-shielding member is not limited to a cross-sectional T shape, An insertion part may be L-shaped cross section. Also in this case, the shape of the groove portion of the main mirror holding frame is a shape corresponding to the shape of the insertion portion of the light shielding member.
In addition, although embodiment and a deformation | transformation form can also be used in combination suitably, detailed description is abbreviate | omitted. Further, the present invention is not limited to the embodiment described above.

  10: camera, 30: mirror unit, 31: main mirror, 33, 233: main mirror holding frame, 37: stepped portion, 50, 250: light shielding member, 51: protruding portion, 52: engaging portion, 238: groove portion, 250: light shielding member, 251: protrusion

Claims (4)

A mirror unit movable between a mirror-up state retracted from the photographing optical path and a mirror-down state arranged in the photographing optical path;
The mirror unit includes a mirror that reflects subject light to the finder in the mirror-down state;
While holding the mirror, it has a step portion formed in a direction perpendicular to the optical axis and recessed from the surface side on which subject light is incident in the mirror down state, and a through hole extending adjacent to the step portion. A mirror holding frame formed with a fitting portion;
A light-shielding member that is fitted into the fitting portion, has a protruding portion that penetrates the through-hole and protrudes from the back side of the mirror holding frame, and an engaging portion that engages with the stepped portion;
A camera comprising: A mirror unit movable between a mirror-up state retracted from the photographing optical path and a mirror-down state arranged in the photographing optical path;
The mirror unit includes a mirror that reflects subject light to the finder in the mirror-down state;
A mirror holding frame that holds the mirror and has a groove portion that extends perpendicularly to the optical axis on the back surface that is the imaging optical path side in the imaging state;
A light shielding member having an insertion part inserted into the groove part, and a protruding part protruding from the back surface of the mirror holding frame;
A camera comprising: The camera according to claim 1 or 2,
The camera, wherein the light shielding member is a foam member. The camera according to claim 1 or 2,
2. The camera according to claim 1, wherein the light shielding member is made of metal and is subjected to antireflection processing.

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