JPS59135405A - Pole light shielding plate for moving lenses of cameras, etc. - Google Patents

Abstract

PURPOSE:To prevent the occurrence of flare on an image pickup face, by providing a light shielding plate, which has a light shielding means of the surface, on the optical-axis side of a pole which moves and guides a lens along the optical axis. CONSTITUTION:Three poles 5 are laid transversely between a flange 3 and a ring 6 of a barrel 2, and a variator 8 and a compensator 14 which are moved back and forth by turning of a cam cylinder 4 are slided and guided by these poles. Light shielding plates 7 are attached to poles 5 on the side of an optical axis L as one body, and ruggedness where a low gloss coating material 17 is applied is formed on a light shielding means 16 which is provided on the optial- axis side of each light shielding plate 7. In case that the variator 8 and the compensator 15 are moved back and foth through poles 5 to photograph, a strong light l1 is absorbed by light shielding means 16 or is reflected irregularly even if it is made incident to the lower side of poles 5 in the optical path. Consequently, the occurrence of flare on the image pickup face is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pole light-shielding plate for moving a lens of a camera, etc., which is attached to a pole that is disposed in a lens barrel of a camera and guides the movement of the lens.

Ideally, there should be no obstructions in the optical path of the lens barrel of a camera, etc., but in a zoom lens called a pole type, for example, a ball and part of its ball holder are placed in the optical path. Since the lens is generally moved along the optical axis, the pole in particular is coated with grease, etc., and is structurally arranged parallel to the optical axis, which tends to cause reflections. As shown in Figure (a) (0), when strong light t1 or l2 enters the optical path from a certain direction and hits the lower ball P1 or upper pole P2 arranged in the optical path, it is reflected and reflected onto the screen S. Flare F on top
However, there was a drawback in that it caused flare F2. Also,
For this reason, Beau/L/P1. Although it is desirable to have a structure in which P2 is disposed outside the optical path, a zoom lens or the like has the disadvantage that its outer diameter is extremely large.

SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and it is an object of the present invention to provide a pole light shielding plate for moving a lens of a camera, etc., which can be attached to a pole disposed in an optical path to prevent the occurrence of flare. This is the purpose.

Next, one embodiment of the present invention will be explained according to the drawings.
1 in the figure shows the zoom part of a zoom lens, for example.
2 is a lens barrel, and the rear end of the same m@2 (right side in the figure (11
11 end) is formed with a mounting flange 6.

Reference numeral 4 denotes a cam surface, which is installed along the inner circumference of the lens barrel 2 so as to be rotatable about the optical axis L4WD. A cam groove (not shown) is formed for moving the scissors in the backward direction, that is, in the wide direction or in the telephoto direction.

Reference numeral 5 denotes a pole horizontally suspended between the mounting flange 5 of the lens barrel 2 and the mounting ring 6 fitted in the front part of the lens barrel 2, and is moved in the front and rear directions 9 by rotation of the cam barrel 4. As shown in FIG. 2, the mounting ring 6 is formed with a mounting portion 6a having two mounting holes 6b on its inner diameter, and the mounting portion 6a has two mounting holes 6b.
A mounting portion 6C having one mounting hole 6d is formed in an inner diameter portion corresponding to the mounting hole 6d. The mounting ring 6 formed in this way is fitted into the front part of the lens barrel 2, and mounting holes 6b, 6 are provided on the side of the mounting flange 3 corresponding to this mounting ring 6.
A mounting hole 3a through which a pole 5 can be inserted corresponds to d, and two wooden poles 5 are disposed on the upper side of the cam cylinder 4 in the drawing, and one pole 5 is disposed on the lower side. Along with this pole 5, a cod light &7, which will be described later, is integrally attached to the pole 5 on the optical axis side along the pole 5 and in a shielding manner.

The upper and lower bows #5 arranged in the cam cylinder 4 in this way
A four Kli variator 8 and a convencator 14 are installed. That is, the mounting frame 9 of the variator 8 is formed with a bearing part 10 that is slidably fitted to one of the two upper poles 5, and a bearing part 10 is formed in the mounting frame 9 of the variator 8. ! -1: An insertion hole 11 through which the light shielding plate 7 can be inserted is provided. Also, open frame 9
has a relief hole 1 through which the other pole 5 and the lighting plate 7 are inserted.
2 is installed through it. Further, a concave groove 16 is formed on the lower side of the receiving frame 9 so as to span the lower pole 5 and the light shielding plate 7, and the width of this groove 13 is formed to be slightly larger than the diameter of the pole 5. It is formed so that it can be slidably moved. Further, in the mounting frame 15 of the convencator 14, the bearing portion 10 and the insertion hole 11 of the first generation frame 9 of the variator 8 and the relief hole 12 are formed in reverse. Also, Ryoji A” frame 9,1
Cam fj is part of 5! (A pin (not shown) is implanted into the cam groove provided in the cam groove 14 so that the J4 can move.
are linked and moved in the wide direction or telephoto direction with respect to the optical axis along the pole 5 via the pin.

Next, the light shielding plate 7 that shields the optical axis side of the upper and lower balls 50 to which the variator 8 and convencator 14 are attached will be explained. The width of the shielding portion 7b is approximately equal to or slightly smaller than the diameter of the pole 5, and the length of the shielding portion 7b is approximately the same as the length of the pole 5. It is formed to a length that can shield the light. A light shielding means 16 is attached to the surface side of the shielding portion 7b formed in this way, and the light shielding means 16 may have, for example, the following technical aspects.

(a) Applying a matte paint 17, which is a mixture of black paint and a matte agent, to the surface of the shielding portion 7b.

(b) Attach black anti-reflection cloth to the surface of the shielding portion 7b.

(c) The surface of the shielding portion 7b is formed into a satin-like texture with concave and convex surfaces by using a method such as shading so that the surface can diffusely reflect the strong light beams 11 and 12.

) A light shielding groove 1 is formed on the surface of the shielding part 7b perpendicularly to the optical axis.
8. For example, as shown in FIG. 4, a large number of V-shaped grooves, square grooves, or substantially trapezoidal grooves are provided at predetermined intervals.

(e) Light-shielding groove 18 on the satin-finished surface or on the above (c)
Apply the matte paint 17 of (a) to the recessed surface.

In the thus formed light shielding plate 7, the hole formed through the mounting portion 7a is fitted into the tip side of the pole 5, and the rear end of the pole 5 is inserted into the mounting hole 6a of the mounting flange B.
The distal end side is inserted into the mounting holes 6b and 6d of the mounting ring B which is fitted into the part 1g11 of the lens barrel 2, and is screwed by a screw 19. Lower light shielding plate 7 installed in this way
The free end side of the rear end is in contact with a pole 5 as shown.

Further, the upper light shielding plate 7 is inserted into the insertion hole 11 and the escape hole 12 of the mounting frames 9 and 15 of the variator 8 and the convencator 14, respectively, and the light shielding plate 7
itself is flammable and the free end side is biased toward the pole side like the lower side, so the front side, that is, the light shielding means 16 side is exposed to the insertion hole 11 and the relief when the mounting frames 9 and 15 move. It is configured so as not to come into sliding contact with the hole 12. Further, it is removably attached in a pressing manner by a retaining screw ring 20 screwed into the front part of the lens barrel 2 with six attachment rings.

In the figure, 21 is a focus lens, and 22 is a master lens.

Next, the operation and effects of this embodiment configured as described above will be explained.

Now, the light shielding plate 7 of this example is arranged in the optical path of the lens barrel 2, and the variator 8 and the convensator 14 are connected to the optical axis LK? 9, a shielding part 7b capable of shielding the upper and lower poles 5 that guide the movement is arranged on the optical axis side thereof, and a light shielding means 16 is attached to the surface side of this shielding part 7b. be. Therefore, when taking pictures by rotating the cam barrel 4 along the optical axis and moving the variator 8 and convencator 14 to the wide position or chill position along the optical axis via the upper and lower poles 5, , If you face it, there will be a strong light I! When light 1 enters the lower pole 5 side in the optical path, the shielding portion 7b of the light shielding plate 7 is arranged along the pole 5 on the optical axis side of the lower pole 5, so that the incident light 11 is directly incident on the lower pole 5 side. It is prevented from hitting the pole 5 and hits the light shielding plate 7. However, since a light shielding means 16 is attached to the front side of this light shielding plate 7, for example, this light shielding means 16 may be coated with the matte paint 17 of (2) or the antireflection cloth paper of (2). in case of,
Most of the strong incident light 11 is absorbed and the reflected light d'
1 is extremely weak, and even if this reflected light A'1 enters the optical path, it does not have a luminous intensity that directly affects the photographing light, thus preventing flare from occurring on the imaging surface 26. be able to. Further, the light shielding means 16 is (c)
If the mirror is formed into a matte finish, the strong incident light 11 is diffusely reflected, and the reflected light becomes extremely weak and does not have a luminous intensity that directly affects the photographing light, causing flare on the imaging surface 26. can be prevented. Further, when the side light means 16) is in the V-viewing direction, for example, when the predetermined use α shown in FIG. The reflected light /'1 that hits the slope iaa is subjected to second or sixth reflection within the V-shaped groove, and its luminous intensity is extremely weakened, eliminating any imprint on the photographing light and creating a flare on the imaging surface. This can be prevented from occurring.

In addition, when the light shielding means 16 is (e), that is, the matte paint 17 is provided with a satin-like surface or with the light shielding grooves 18 recessed.
By applying , the light shielding effect can be significantly enhanced and the occurrence of flare can be prevented. Therefore, each pole 5 can be sufficiently coated with grease, etc., and the variator 8 and convencator 14 can be operated smoothly. Further, there is an advantage that the light shielding plate 7 can be easily attached and detached using the retaining screw ring 20 and the screw 19.

In addition, the mounting part 7a of the light plate 7 is attached to the mounting ring 6 and the pole 5.
Although the example is shown in which the mounting part 7 is mounted in a wedge-like manner, the mounting part 7 is not limited to this, for example, as shown in FIG.
/a may be attached to the front part of the attachment ring 6. Although the agricultural shielding portion 7b of the light shielding plate 7 is exemplified to have a length that covers the entire ball 5, the length is not limited to this, and any length may be used as long as it prevents harmful reflected light from the poles 5. .

Now, in the present invention, the pole is disposed in the optical path of the lens barrel to guide the movement of the lens along the optical axis, and the pole is disposed in a shieldable manner on the optical axis side, and a light shielding means is attached to the surface side. This is a ball light shielding plate for moving the lens of a camera, etc., so even if strong light enters the optical path during shooting, the pole is shielded by the light shielding plate and the incident light does not directly hit the pole. The incident light is blocked and hits the light shielding plate, but since a light shielding means is attached to the front side of the seat front board, the strong incident light is absorbed by this picture light means, diffusely reflected, etc., and the luminous intensity of the reflected light is reduced. It is possible to prevent flare from occurring on the imaging surface by weakening the light and preventing it from affecting the photographing light, and for this reason, it is possible to sufficiently apply lubricant to the pole. Since the lens can be moved smoothly, it can be extremely useful as a pole light shielding plate for moving lenses of cameras, etc.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, in which Fig. 1 is a sectional view of the zoom section on the road body, Fig. 2 is a perspective view showing the relationship between the mounting ring and the pole, and Fig. 6 is a road body of the mounting frame. 4(A) is a front view of a light shielding plate having a light shielding groove, FIG. 4(B) is an enlarged view of the light shielding groove, FIG. 5 is a perspective view showing another mode of mounting the light shielding plate, and FIG. Figures (a) and (b) are explanatory diagrams of conventional examples. 2... Lens tube 5... Pole 7... Light shielding plate 7b... Shielding part 8... Variator
14... Convencator 16... Light blocking means 17... Matte paint 18... Light blocking groove
L... Optical axis applicant Kowa Co., Ltd.

Claims (6)

[Claims] (1) The ball is disposed in a shieldable manner on the optical axis side of a pole that is disposed in the optical path of the lens barrel and guides the movement of the lens along the optical axis, and a light shielding means is attached to the surface side. A pole light-shielding plate for moving lenses of cameras, etc., which is characterized by: (2) A pole light shielding plate for moving a lens of a camera or the like as set forth in claim 1, wherein the light shielding means has a matte paint applied to the surface of the light shielding plate. (3) The light-shielding means is an anti-reflection cloth paper pasted on the front side of the light-shielding plate. ￥'f A pole construction plate for moving a lens of a camera, etc., as set forth in claim 1. (4) A pole light-shielding plate for moving a lens of a camera, etc., as set forth in item 1, item 1, of claim 1, wherein the light-blocking means has a surface of the light-shifting plate formed in a matte texture with unevenness. (5) The light shielding means is the surface of the light plate [nj and edge light lil\
A claimed pole light-shielding plate characterized by having multiple concave grooves perpendicular to the optical axis. (6) The light shielding means is characterized in that a matte paint is further applied to the matte surface or the upper surface of the light shielding groove formed on the surface of the light shielding plate. Pole light shielding board.