JP3406671B2 - Light blocking device for lens barrel - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel shading device for shading between a fixed barrel and a moving barrel.

[0002]

2. Description of the Related Art A recent camera, for example, a lens shutter type camera, has a fixed lens barrel fixed to a camera body and a fixed lens barrel that is supported in the fixed lens barrel and can move back and forth in the optical axis direction with respect to the camera body. It has a movable lens barrel. In a camera having such a structure, an annular light shielding member that prevents outside light from entering through a gap between the fixed lens barrel and the movable lens barrel is usually provided in the front portion of the camera body.

By the way, when a gap is formed between the movable lens barrel and the light blocking member due to deformation, for example, outside light enters through the gap between the lens barrel despite the presence of the light blocking member. To do. In order to prevent such a problem, for example, it is conceivable that the light shielding member is formed long in the optical axis direction so as to prevent outside light from entering regardless of some deformation. However, in such a case, an extra space is required due to an increase in the size of the light shielding member, which violates the demand for a compact camera.

[0004]

SUMMARY OF THE INVENTION The present invention has been made on the basis of the above-mentioned awareness of the problems, and makes it possible to reliably prevent external light from entering between the fixed lens barrel and the movable lens barrel while suppressing the length in the optical axis direction. It is an object of the present invention to provide a light blocking device for a lens barrel that can prevent it.

To achieve this object, the present invention provides a fixed lens barrel fixed to a camera body ; a movable lens barrel supported in the fixed lens barrel and movable in the optical axis direction with respect to the camera body ; The movable lens barrel is pulled out from behind the optical axis of the movable lens barrel.
Going forward between the outer surface of the lens and the inner surface of the fixed lens barrel.
The flexure that is pulled out from the front of the fixed lens barrel to the outside of the fixed lens barrel.
Upper in the lens barrel including the said light leakage prevention means, the optical axis direction position varied back and forth; unwilling substrate; and light leakage prevention means for shielding between the moving lens barrel and the fixed barrel
It is fixed inside the fixed lens barrel, and each is fixed outside the movable lens barrel.
Obtain Bei the first and second light shielding ring member for elastically contacting slidably with respect to the circumferential surface; an inner peripheral portion of the first light-shielding ring member located towards front optical axis direction is bent backward, backward The second light-shielding ring member located at is the elastic contact point with the movable lens barrel.
The inner diameter size of the front part of the
To obtain Bei a receiving space portion of the annular housing the rear bent portion of the light shielding ring member; second shading ring member further fixed
Hold the flexible substrate between the inner surface of the lens barrel and
It is characterized in that the relative movement of the flexible substrate with respect to the fixed lens barrel is restricted .

According to the above-mentioned light-shielding device, since the two light-shielding ring members located back and forth in the optical axis direction are located between the fixed lens barrel and the movable lens barrel, the light-shielding device is provided outside the gap between the lens barrels. Intrusion of light is surely prevented. Further, since the rear bent portion bent to the optical axis rear side can be housed in the housing space of the second light shielding ring member, a part of both light shielding ring members can be aligned in the optical axis direction. Although the two light leakage prevention units are provided, the length of the light leakage prevention unit in the optical axis direction is shortened. In addition, the second light blocking ring member
Also functions as a holding member that holds the bull substrate on the fixed barrel.
Therefore, the number of parts can be saved.

Further, the second light-shielding ring member can be provided with bristles on the inner peripheral portion behind the storage space portion.

Further, the movable lens barrel advances and retreats between a projecting position from the camera body and a storage position to be stored in the camera body, and at this storage position, it is located in substantially the same plane as the front wall of the camera body. In the case of having the small-diameter step portion, if the rear bent portion does not come into contact with the small-diameter step portion in the entire movement range of the movable lens barrel between the projecting position and the storage position, the rear bent portion of the first light shielding ring member is No gap is generated between the movable lens barrels. Therefore, it is possible to make the light blocking between the fixed lens barrel and the movable lens barrel more reliable.

[0009]

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments. FIG. 1 is a cross-sectional view showing a main part of a collapsible single-focal-length lens-shutter camera to which the present invention is applied, which is vertically cut along the optical axis
FIG. 2 is an exploded perspective view showing a main part of a lens barrel unit of the lens shutter type camera.

Reference numeral 11 in the figure shows a camera body, which has a fixed block 13 inside. A fixed lens barrel 21 is integrally fixed to the fixed block 13, and a cylindrical movable lens barrel housing portion 22 formed in the fixed lens barrel 21 has lenses such as a shutter block 41 and a lens group L. A movable lens barrel 31 on which relevant main members are mounted is fitted so as to be movable back and forth in the optical axis direction. The movable lens barrel housing portion 22 has a guide groove portion 23 extending parallel to the optical axis O, and the movable lens barrel 3 is provided in the guide groove portion 23.
A guide projection 32, which is provided on the outer peripheral surface of 1, is retractably housed. The guide protrusion 32 is formed with two guide holes 33 and 34 extending in parallel with the optical axis O.
Also, the shutter block 41 and the CP in the camera body 11
U, a power source (not shown), etc. are provided on the flexible substrate 51.
Are electrically connected by.

One guide hole 33 has a guide groove 23.
A guide pole 60 fixed in parallel to the optical axis O is slidably fitted therein, whereby the movable lens barrel 31 is slidable in the optical axis O direction with respect to the movable lens barrel housing portion 22. Is being guided by. A female screw 35 is inserted into the other guide hole 34 and is fixed to the guide protrusion 32 by a pressing plate 36. Since the feed screw 63 for driving the movable barrel 31 forward and backward in the optical axis direction is screwed into the female screw 35, the movable barrel 31 is guided by the guide pole 60 by the rotation of the feed screw 63. Moves back and forth along the optical axis.

The front and rear ends of the guide pole 60 are axially supported by a parent plate 61 and a bearing plate 62, which are screwed to the fixed barrel 21. The front and rear ends of the feed screw 63 are also pivotally supported by the parent plate 61 and the bearing plate 62, respectively. A brush 28 and an AF code plate 34 for detecting the position of the fixed lens barrel 21 in the optical axis direction in a relatively large step are provided on the bottom surface of the guide groove portion 23 and the lower end surface of the guide hole 33 facing the bottom surface, respectively. There is. On the bearing plate 62, a light shielding portion 62a for bending harmful reflected light from the guide pole 60 and the like is bent and formed. An antireflection process such as attaching an antireflection member is applied to the surface of the light shielding portion 62a which faces the photographing optical path.

Gears 65, 66 and 67, which form a reduction gear train, are axially supported on the main plate 61. A gear 64 is fixed to the tip of the feed screw 63.
3 is linked with an encoder plate 68 via a gear 65 meshing with the gear 64 and gears 66, 67 meshing with the gear 65. The encoder plate 68 cooperates with the photo interrupter 69 to form a known rotation detecting means, and detects the rotation amount of the feed screw 63, that is, the position of the fixed barrel 21. Further, the feed screw 63 is driven by the motor 70 mounted on the fixed barrel 21 so that the motor pinion and the gears 66, 65,
Driven via 64. Incidentally, reference numeral 69b in FIG.
Is a cushion interposed between the photo interrupter 69 and the master plate 67 in a compressed state, and fixes the photo interrupter 69 to the master plate 67 by its elastic restoring force. Reference numeral 25 in the figure is a space formed in the fixed lens barrel 21 for accommodating the pulse plate 68, the photo interrupter 69, and the gear train.

The movable lens barrel 31 has a decorative plate 52 at the front end. The decorative plate 52 is arranged so as to be located substantially in the same plane as the front wall 11a of the camera body 11 in the housed state shown in FIG. A shutter block 41 is fixed inside the movable lens barrel 31, as shown in FIG. The shutter block 41 includes a normally closed shutter blade 43, and when a predetermined shutter drive signal is input from the shutter control device via the flexible substrate 51, the shutter blade 43 is opened and closed to perform a predetermined exposure. The lens group L is fixed to the tip of the shutter block 41 via a lens holding frame 45. Reference numeral 47 in the figure is a shutter mask that cuts off light other than image forming light, and also has a function of covering the flexible substrate 51 exposed on the film surface 18 side of the shutter block 41.

Next, the mounting structure of the flexible substrate 51 will be described. The flexible substrate 51 is shown in FIGS.
And, as shown in FIG. 9, the winding portion 51c and the straight portion 51d.
Are housed in a substrate housing recess 24 formed on the inner peripheral surface of the movable lens barrel housing 22, one end of which is drawn from the front end of the fixed lens barrel 21 toward the inside of the camera body 11, and the other end. The portion extends rearward of the optical axis of the movable lens barrel 31, is drawn into the movable lens barrel 31 from the rear side through the curved portion 51e, and is connected to the shutter block 41.

The flexible substrate 51 is the camera body 1
In order from the connecting portion 51a connected to the control means provided in a portion other than the fixed lens barrel 21 in the first embodiment, from the gap between the photo interrupter 69 and the fixed lens barrel 21 to the fixed lens barrel 21.
Bent portion 51b entering inside, flexible substrate housing recess 24
A circling portion 51c that circulates along with a linear portion 51d that bends from this circling portion 51c and moves parallel to the optical axis O and extends rearward of the lens barrel 31 toward the film surface 18 and moves by changing the direction by 180 degrees. It includes a curved portion 51e that enters the lens barrel 31, and a connection end portion 51f that is bent downward in FIG. 1 and that is connected to the shutter block 41. This curved part 5
1e follows (moves) the moving lens barrel 31 by moving (extending and contracting) in the optical axis direction when the moving lens barrel 31 moves in the optical axis direction.

FIG. 3 shows a state in which the flexible substrate 51 mounted on the movable lens barrel 31 is housed in the substrate housing recess 24. Although not shown in detail, the substrate storing recess 24 includes a rotating recess 24a extending in the rotating direction for storing the rotating portion 51c and a linear recess 24b extending in the optical axis direction for storing the straight portion 51d.

On the other hand, the tip of the fixed lens barrel 21 and the movable lens barrel 3
As shown in FIG. 4, outside light is exposed between the lens barrel 1 and the lens barrel 2
A light leakage prevention unit is provided to prevent the light from entering the camera body 11 through the gap between the first and the third members. The light leakage prevention unit includes an annular light-shielding curtain (first light-shielding ring member) 86,
It is provided with a C-shaped substrate restriction ring (second light-shielding ring member) 81 fitted in the movable lens barrel 31.

The fixed ring 21 has a front end portion 21a, which is engaged with an engaging portion 11b provided on the inner surface of the front wall 11a of the camera body 11, and a light-shielding curtain 86, together with the holding ring 85, from the front to the rear. A large-diameter holding portion 21b formed to have a large diameter for fitting, a fitting portion 21c into which the flange 81a of the board regulating ring 81 is fitted, a positioning hole 21d (FIG. 5) formed in the fitting portion 21c, And a small diameter portion 21e in order.

As shown in FIGS. 2 to 4, the substrate restricting ring 81 is formed in a C-shape from an elastic synthetic resin or the like, and is configured to tighten the movable lens barrel 31 by its elastic force. The board regulating ring 81 has a flange 81a protruding from the outer peripheral surface thereof, a positioning protrusion 81b formed by projecting a front portion of the flange 81a outward in the radial direction, and a large diameter formed on the inner peripheral side of the positioning protrusion 81b. Section 81d,
Further, it has a flocked portion 81c which is smaller in diameter than the large diameter portion 81d and is located on the optical axis rear side. The board regulating ring 81 is a fitting portion 21c on the inner circumference of the fixed ring 21 (moving lens barrel housing portion 22).
In the state of being fitted in, the positioning protrusion 81b is engaged with the positioning hole 21d in the inner peripheral surface of the fitting portion 21c, whereby the rotation and the movement in the optical axis direction are restricted. The substrate regulation ring 81 has a flocked portion 81c to which a light-blocking flock 84 is attached. The tip of the flocked portion 84 is elastically brought into contact with the outer peripheral surface of the movable lens barrel 31, and the substrate regulation ring 8 is moved.
The gap between 1 and the movable lens barrel 31 is shielded from light.

Now, the relationship between the board regulating ring 81 and the flexible board 51 will be described with reference to FIGS. 3, 6 and 7. The circling portion 51c of the flexible substrate 51 is housed and held in the space regulated by the substrate housing recess 24, the outer peripheral surface of the substrate restricting ring 81, and the flange 81a. A flange 81a is not provided at a portion where the flexible substrate 51 extends from the movable lens barrel housing 22 into the camera body 11. Therefore, the flexible substrate 51 is
The movable lens barrel housing portion 22 is passed through the bent portion 51b and the introduction groove 38 formed in the end portion of the movable lens barrel housing portion 22 in the diametrical direction.
It goes out and the end 51 a extends into the fixed block 13. In this way, the board regulating ring 81 serves as both the second light-shielding ring member and the holding member that holds the flexible substrate 51 on the fixed lens barrel 21, so that the number of parts can be saved.

On the other hand, the light shielding curtain 86 is an annular member made of a flexible material, and is attached to the front side of the optical axis of the holding ring 85 having rigidity. The retaining ring 85 is formed such that its radial width is smaller than that of the light shielding curtain 86. Only the outer peripheral portion 86a of the light shielding curtain 86 is attached to the holding ring 85, and the free end portion on the inner peripheral side is bent toward the rear side of the optical axis to form a rear bent portion 86b. The light-shielding curtain 86 is slidably fitted to the outer periphery of the movable lens barrel 31 so as to be located between the front end portion of the fixed lens barrel 21 and the inner surface of the front wall 11a, and is housed in the substrate regulating ring 81 and the movable lens barrel storage. The portion 22 and the fixed lens barrel 21 and the movable lens barrel 31 are shielded from each other. The light shielding curtain 86 completes the light shielding especially near the bent portion 51b where the flexible substrate 51 is pulled out from the movable lens barrel housing portion 22 (retracted into the movable lens barrel housing portion 22).

Further, the light shielding curtain 86 has a rear bent portion 86b.
Are housed in the housing space 48 formed by the large diameter portion 81d. The light-shielding curtain 86 and the substrate restriction ring 81, which are light leakage prevention means, are part of each, that is, the rear bent portion 8
By making the positions of 6b and the large-diameter portion 81d on the optical axis coincide with each other, the length in the optical axis direction is shortened, and the light blocking between the fixed space 21 and the movable lens barrel 31 is made more reliable. . For example, as compared with the case where the large diameter portion 81d is not provided in the substrate restriction ring 81 and the inner peripheral free end portion of the light shielding curtain 86 is arranged forward of the optical axis as shown in FIGS. Can be easily understood.

That is, when the movable lens barrel 31 shown in FIG. 10 is housed, and the decorative plate 52, which has a diameter smaller than that of the movable lens barrel 31 and forms a small-diameter step portion, has luster rather than matte, this decorative plate 52 is used. The external light a reflected by the outer peripheral surface of the
The light is not completely shielded by entering through the gap between the free end of the inner circumference and the decorative plate 52. Also, as shown in FIG.
Fig. 1 shows the case where the mat is matted and screwed.
As in the case of 0, the outside light b reflected by the screw 53 forming the small-diameter step portion, the inner peripheral free end portion of the light shielding curtain 86 and the decorative plate 5
It penetrates through the gap between 2 and the light blocking is not perfect. However, according to this embodiment of the present invention, as shown in FIGS. 4 and 8, when the movable lens barrel 31 is stored, the light shielding curtain 86 is provided.
The inner peripheral free end portion (rear bent portion 86b) is bent rearward of the optical axis and contacts the outer peripheral surface of the movable lens barrel 31, and the rear bent portion 86b partially overlaps with the substrate regulating ring 81 on the optical axis. Since they are matched, the external light c reflected by the glossy decorative plate 52 and the external light d reflected by the screw 53 are both eclipsed by the rear bent portion 86b of the light shielding curtain 86. The board regulating ring 81 makes this light shielding by the rear bent portion 86b more reliable.

The present invention can also be applied to lens barrels having other structures such as non-collapsible lens barrels and zoom lens barrels.

[0027]

As described above, the light shielding of the lens barrel of the present invention
According to the device, light leakage prevention means, during solid Teikagami tube a moving barrel, since includes two light shielding ring member located one behind the optical axis direction, out of the gap between the barrel Intrusion of light is surely prevented. In addition, the first shield that is bent to the rear of the optical axis
The rear bent portion of the optical ring member is housed in the storage space of the second light shielding ring member, and a part of both light shielding ring members is oriented in the optical axis direction.
Since they can be matched in the direction, the length of the light leakage prevention unit in the optical axis direction is shortened even though the two light blocking ring members are provided. In addition, the second light shield
The holding member holds the flexible substrate on the fixed barrel.
Saves the number of parts as it also functions as a holding member.
You can

Further, the movable lens barrel advances and retreats between a projecting position from the camera body and a housing position housed in the camera body, and at this housing position, the lens barrel is located substantially on the same plane as the front wall of the camera body. In the case of having the small-diameter step portion, if the rear bent portion does not come into contact with the small-diameter step portion in the entire movement range of the movable lens barrel between the projecting position and the storage position, the rear bent portion of the first light shielding ring member is No gap is generated between the movable lens barrels. Therefore, it is possible to make the light blocking between the fixed lens barrel and the movable lens barrel more reliable.

[0029]

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of a lens shutter camera to which the present invention is applied, which is longitudinally cut along an optical axis.

FIG. 2 is an exploded perspective view showing a main part of a lens barrel unit of the lens shutter type camera.

FIG. 3 is a cross-sectional view of the vicinity of a mounting portion of a flexible substrate, which is cut in a direction orthogonal to an optical axis and shown from the front.

4 is an enlarged sectional view taken along line IV-IV in FIG.

5 is an enlarged sectional view taken along line VV in FIG.

6 is an enlarged sectional view taken along line VI-VI in FIG.

7 is an enlarged sectional view taken along line VII-VII in FIG.

FIG. 8 is an enlarged cross-sectional view showing a case in which screws are screwed into the decorative plate in FIG.

FIG. 9 is a perspective view of a flexible substrate of the same example.

FIG. 10 is an enlarged cross-sectional view showing an example in which the inner peripheral free end of the light shielding curtain is bent forward of the optical axis.

FIG. 11 is an enlarged cross-sectional view showing an example in which the inner peripheral free end of the light shielding curtain is bent forward of the optical axis.

[Explanation of symbols]

11 Camera Body 21 Fixed Lens Barrel 31 Moving Lens Barrel 48 Storage Space 51 Flexible Board 52 Decorative Plate (Small Diameter Step) 53 Screw (Small Diameter Step) 81 Substrate Restricting Ring (Second Light-Shielding Ring Member, Leakage Prevention Means) 84 Flocking 86 Light-shielding curtain (first light-shielding ring member, light leakage prevention means) 86a Outer peripheral portion 86b Rear bent portion O Optical axis

Claims (3)

(57) [Claims] 1. A fixed lens barrel fixed to a camera body ; a movable lens barrel supported in the fixed lens barrel and capable of moving forward and backward in the optical axis direction with respect to the camera body ;
Between the outer peripheral surface of the movable lens barrel and the inner peripheral surface of the fixed lens barrel.
Through the front of the fixed barrel and pull it out of the fixed barrel.
And, light leakage prevention means for shielding between the moving lens barrel and the fixed barrel; can the flexible substrate is issued in the lens barrel including the said light leakage prevention means is varied back and forth in the optical axis direction position
Fixed inside the fixed barrel, each of the movable barrel
E Bei first and second light shielding ring member for elastically contacting slidably with respect to the outer peripheral surface, the inner peripheral portion of the first light-shielding ring member located towards front optical axis is bent backwards, the rear The second light-shielding ring member located is located at the front of the elastic contact point with the movable lens barrel.
Bei example a receiving space portion of the annular inner diameter sized to house the <br/> rear bent portion of the larger the first light-shielding ring member than the second light-shielding ring member further inner peripheral surface of the fixed lens barrel
Holding the flexible substrate between the flexible substrate and
A light-shielding device for a lens barrel, characterized in that it restricts relative movement of the substrate to the fixed barrel . 2. The lens barrel light-shielding device according to claim 1, wherein the second light-shielding ring member is provided with flocked hair at an inner peripheral portion behind the storage space portion. Shading device. 3. A shield for a lens barrel according to claim 1 or 2.
In the optical device , the movable lens barrel moves back and forth between a projecting position from the camera body and a storage position housed in the camera body, and is located in substantially the same plane as the front wall of the camera body at the storage position. A small-diameter step portion is provided at the tip portion, and the rear bent portion of the first light-shielding ring member is located rearward of the small-diameter step portion in the entire movement range of the movable lens barrel between the protruding position and the storage position. A light blocking device for a lens barrel that does not come into contact with the small-diameter step portion .