JP3447013B2 - Anti-reflection device inside lens barrel of zoom camera - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing internal reflection inside a lens barrel in a zoom camera.

[0002]

2. Description of the Related Art In a zoom camera, a light-shielding plate or the like is provided to prevent internal reflection inside a lens barrel. Conventionally, a light-shielding plate fixed or a light-shielding member fixed to a movable cam barrel is used. A plate or flocked paper provided in a lens barrel is known.

[0003]

However, first of all, in the case of a zoom camera or the like, the angle of the incident light beam is different between the retracted state and the extended state in the case of the fixed light-shielding plate, and sufficient light-shielding is performed at both positions. Hard to get. Further, since the light shielding plate is fixed in the middle, a space corresponding to that is required when the lens is stored, which is not suitable for downsizing.

Next, in the case of a light-shielding plate fixedly mounted on a movable cam barrel or the like, as in the above case, due to the difference in the angle of the incident light beam, it cannot be said that the light-shielding is sufficient when it is extended. Also, in the case of flocked paper, since it is attached inside the lens barrel,
There was a drawback that the diameter of the lens barrel would inevitably increase.

Therefore, an object of the present invention is to reduce the size of a zoom camera by moving the light shield plate at a substantially constant interval with respect to the effective light rays in accordance with the zooming operation of the lens barrel, thereby reducing harmful effects. An object of the present invention is to provide a lens barrel inner surface antireflection device capable of effectively preventing inner surface reflection.

[0006]

In order to solve the above problems, the internal reflection preventing device for a lens barrel of a zoom camera according to the present invention comprises:
A lens barrel having a forward barrel and a fixed barrel having a light blocking plate therein, a camera body having the fixed barrel fixed therein, and a movement of the forward barrel with respect to the fixed barrel by connecting the forward barrel and the camera body. A flexible printed circuit board that follows
In the zoom camera having the above-mentioned, the flexible printed circuit boards are provided in a bent state at least at three positions in the circumferential direction of the lens barrel, and the light shielding plate has an annular plate shape while preventing internal reflection of the lens barrel, and the flexible print is provided. It is characterized in that it moves a distance that is half the moving distance of the advancing cylinder while contacting each bent end of the substrate.

A spring is further provided for urging the light shielding plate in a direction in which the light shielding plate is brought into contact with the bent end portion of the flexible printed circuit board.

[0008]

The light-shielding plate follows the movement of the flexible printed circuit board during the zooming operation and moves while contacting the bent end portion thereof, that is, about half of the movement of the forward movement cylinder or the like provided with the shutter mechanism and the like. In order to constantly move the part, the internal reflection is prevented by moving the effective ray at a substantially constant interval. Further, by making at least three flexible printed boards equivalent in force, it is possible to support the light shielding plate at at least three bent ends and move the light shielding plate in parallel.

For example, the light shielding plate is driven by a spring.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the internal reflection preventing device for a lens barrel of a zoom camera according to the present invention will be described below with reference to FIGS.

First, in FIGS. 1 to 4 showing the configuration of a lens barrel of a zoom camera as an example to which the present invention is applied, 1
Is a camera body, 2 is a fixed barrel, 3 is a straight-moving barrel, 4 is a rotating barrel,
Reference numeral 5 is a forward cylinder, 6 is a cam cylinder, 7 is a lens holding cylinder, 8 is a lens, 9 is a flexible printed circuit board (hereinafter abbreviated as FPC), 10 is an FPC pressing plate, 11 is a movable light shielding plate, 1
Reference numeral 2 is a light shielding plate driving spring.

A fixed barrel 2 is fixed inside the camera body 1, and a straight-moving barrel 3 is arranged inside the fixed barrel 2.
A straight advancing groove 2a is formed in the fixed cylinder 2 along the axial direction thereof, and a projection 3a formed on the outer periphery of the straight advancing cylinder 3 is engaged with the straight advancing groove 2a. A rotary cylinder 4, a forward cylinder 5, and a cam cylinder 6 are arranged inside the straight-moving cylinder 3, and further,
A lens holding cylinder 7 is arranged inside the cam cylinder 6. A lens 8 is fixed inside the lens holding cylinder 7.

In the above lens barrel, the rectilinear barrel 3 and the forward barrel 5 are moved back and forth along the axial direction by the rotation of the rotary barrel 4 and the cam barrel 6. Further, by rotating the cam barrel 6, the lens holding barrel 7 is moved back and forth. Such a method of driving the lens barrel is a conventionally known method, and a detailed description thereof will be omitted here.

An FPC accommodation groove 2b is formed in the fixed cylinder 2 along the axial direction thereof, and an FPC 9 for connecting the fixed cylinder 2 and the forward movement cylinder 5 is accommodated in the FPC accommodation groove 2b. . That is, in the state of being bent in the shape of a U in the middle, one end is connected to a shutter mechanism or the like (not shown) provided in the advancing cylinder 5, and the other end is connected to the fixed cylinder 2.
Is housed in the FPC housing groove 2b, and the FPC housing groove 2
b is closed from the outside by the FPC pressing plate 10.

In the embodiment, the FPCs 9 are provided at three positions in the circumferential direction of the lens barrel, so that the FPC receiving groove 2b is also three.
It is a book. At least one of the three FPCs 9, 9, 9 has wiring for electrically connecting the camera body 1 and the shutter mechanism of the forward movement barrel 5, and the other has no function of electrically connecting. Therefore, the dummy FPC is equivalently competent. In addition, these three FP
Of course, it may have wirings electrically connected to C9, 9, and 9.

Further, the U of these three FPCs 9, 9, 9
A ring-shaped movable light-shielding plate 11 is arranged so as to come into contact with the bent end of the character shape. This movable light-shielding plate 11 has projecting pieces 11a, 11 at three locations in the circumferential direction on the outer periphery of its ring plate portion.
a, 11a, and these protruding pieces 11a, 11a,
Straight grooves 2 provided with 11a at three positions in the circumferential direction of the fixed cylinder 2.
a, 2a, 2a, respectively.

Then, the spring locking pieces 11b, 11b, 11b extending from the projecting pieces 11a, 11a, 11a and the spring locking pins 2c, 2c, 2 provided on the outer periphery of the front portion of the fixed cylinder 2 are provided.
The ring plate portion of the movable light shielding plate 11 is connected to the FPCs 9, 9,
Light-shielding plate drive springs 12, 12, 12 by a weak tension coil spring that is necessary and sufficient for always contacting the bent end of 9
Are stretched respectively.

According to the internal reflection preventing device for a lens barrel having such a structure, when the forward moving barrel 5 moves back and forth with respect to the fixed barrel 2 due to the zooming operation, the three FPCs 9, 9, 9 are U-shaped. A movable light-shielding plate 11 that abuts the bent end of the mold
Moves the half distance of the advancing barrel 5 by the force of the light shielding plate driving springs 12, 12, 12 and cuts harmful rays.

That is, (a) from FIG. 5 to FIG.
As shown in (b), (c), (d), (e), and (f) of the variable magnification operation state, the movable light-shielding plate 11 is moved to the forward barrel 5.
The movement of half of the movement of
Since the movable light shielding plate 11 moves at a constant interval, for example, as shown in FIGS. 5 (a) and 6 (c), harmful rays 14 tend to be reflected on the inner surface of the lens barrel (fixed barrel 2). Can be effectively prevented by the moving light shielding plate 11.

In the above embodiment, the three FPCs including the dummy are provided for the stable support of the light shield plate.
The present invention is not limited to this, and four or more F
It may be a PC. Further, the material of the light shielding plate, the type of spring, and the like are arbitrary, and for example, a compression coil spring can be used instead of the tension coil spring, and other specific detailed structures can be appropriately changed. Of course.

[0021]

As described above, according to the inner reflection preventing device for a lens barrel of the zoom camera according to the present invention, the flexible printed circuit board is moved along with the movement of the flexible printed circuit board during the zooming operation, and the flexible printed circuit board is brought into contact with the bent end portion thereof. However, since the shading plate moves, that is, the shading plate moves about half of the movement of the forward movement cylinder or the like provided with the shutter mechanism, etc. Internal reflection can be effectively prevented. Moreover, because it is a moving light shield,
The lens barrel can be made compact. In addition, at least 3
By making the two flexible printed boards equivalent in force, the light shielding plate can be supported and moved in parallel at at least three bent ends.

As described in claim 2, the light shielding plate can be driven by providing a spring for urging the light shielding plate in a direction in which the light shielding plate is brought into contact with the bent end portion of the flexible printed circuit board.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a configuration of a lens barrel of a zoom camera as an example to which the present invention is applied.

2 is a cross-sectional view taken along the line II of FIG.

3 is a half sectional view taken along the line II-II in FIG.

FIG. 4 is a half sectional view taken along the line III-III in FIG.

5A and 5B are views showing a mode in which the lens barrel is in a variable magnification state, wherein FIG. 5A is a half-section vertical side view in a telescope state, and FIG. 5B is a half-section vertical side view in a state shorter than the telescope state. .

FIG. 6 is also a view showing a mode of a variable magnification state of the lens barrel,
FIG. 5C is a side view of the half part longitudinally cut in a state shorter than that of FIG. 5B, and FIG. 5D is a side view of the half part longitudinally made shorter than the state of FIG. 5C.

FIG. 7 is a view showing a mode in which the lens barrel is in a variable magnification state.
FIG. 6E is a side view of a half section in a wide state, which is shorter than the state in FIG. 6D, and FIG. 6F is a side view of a half section in a retracted state, which is shorter than the state in FIG. 6E.

[Explanation of symbols]

1 camera body 2 fixed cylinder 2a Straight groove 2b FPC housing groove 2c Spring locking pin 3 straight barrel 3a protrusion 4 rotating cylinder 5 Forward cylinder 6 cam barrel 7 Lens holding tube 8 lenses 9 Flexible printed circuit board (FPC) 10 FPC holding plate 11 Moving light shield 11a protruding piece 11b Spring locking piece 12 Light-shielding plate drive spring 13 Effective rays 14 Harmful rays

Continuation of front page (56) Reference JP-A-5-100139 (JP, A) JP-A-4-257834 (JP, A) JP-A-63-201613 (JP, A) JP-A-1-142609 (JP , A) JP-A-56-77810 (JP, A) JP-A-56-77809 (JP, A) JP-A-56-66809 (JP, A) Actual development 63-39217 (JP, U) Actual development 63-109912 (JP, U) Actual flat 2-90811 (JP, U) Actual flat 3-24619 (JP, U) Actual flat 2-7634 (JP, U) Actual flat 4-119413 (JP, U) Jitsuko Sho 47-4377 (JP, Y1) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02B ^7/ 02-7/105 G02B ⁷ /12-7/16

Claims (2)

(57) [Claims] 1. A lens barrel having a forward barrel and a fixed barrel having a light blocking plate therein, a camera body having the fixed barrel fixed therein, and a forward barrel connecting the forward barrel and the camera body. In a zoom camera having a flexible printed circuit board that follows the movement with respect to the fixed barrel, the flexible printed circuit boards are provided in a bent state at at least three positions in the circumferential direction of the lens barrel, and the light shielding plate reflects the inner surface of the lens barrel. In addition, it is an annular plate shape, and while moving in contact with each bent end of the flexible printed circuit board, it moves a distance that is half the moving distance of the advance barrel. apparatus. 2. The internal reflection preventing device for a lens barrel of a zoom camera according to claim 1, further comprising a spring for urging the light shielding plate in a direction in which the light shielding plate is brought into contact with a bent end portion of the flexible printed circuit board.