JPH0714442U - Light leakage prevention mechanism for camera lens shutter - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the thickness of the main plate structure that houses the shutter blades in a lens shutter for a camera, while taking light leakage prevention into consideration. [Structure] Similar to the opening 1b of the shutter base plate 1, an opening 5b is provided in the cover plate 5. The drive pin 2a is fitted into the slots 6b and 7b of the shutter blades 6 and 7 through the opening 1b, and the tip of the drive pin 2a is in the opening 5b. Drive pin 2
A light-shielding plate 8 is rotatably fitted between the shutter blades 6 and 7 at a.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a light leakage prevention mechanism for a camera lens shutter.

[0002]

[Prior art]

 Recent compact cameras have come to incorporate many functional parts including the autofocus mechanism. Among these parts, those related to the shutter and the lens are usually provided in front of the operation surface of the shutter blades, and most of them are attached to the shutter base plate. Therefore, in designing the lens shutter, in order to make it applicable to various cameras, it is necessary to reduce the area of the shutter base plate as much as possible and the length in the direction along the optical axis as much as possible. Has become. Then, as one of the methods for dealing with such a problem, the shutter base plate and the cover plate that house the shutter blades so as to be sandwiched are made as thin as possible to cover the shutter base plate from the object side surface. Efforts are being made to reduce the dimension of the plate to the film side. However, the problem in this case is how to prevent the leading end of the drive pin fitted in the slot of the shutter blade from hitting the cover plate for opening and closing the shutter blade. . In order to solve this point, conventionally, the following two countermeasures have been mainly taken. One of them is a method of denting a part of the cover plate toward the film only in the operation region at the tip of the drive pin. Another method is to provide an opening in the cover plate over the operation region of the drive pin, similarly to the opening for driving the drive pin provided in the shutter base plate. However, in this case, the light on the front surface (subject side) of the shutter base plate may leak through the opening of the shutter base plate, the slot of the shutter blades, and the opening of the cover plate to reach the film surface on the back surface of the cover plate. Therefore, in order to prevent light from leaking from other parts, the influence is usually removed by a light-shielding tube provided between the shutter and the film surface.

[0003]

[Problems to be Solved by the Invention] However, when the cover plate is provided with a recess as described above, there is no need to worry about light leakage, but since the recessed portion projects to the opposite side, This imposes restrictions on the configuration of other camera parts placed there, which is not preferable from the viewpoint of the design of shutters that can be incorporated into various cameras. Also, as described above, the cover plate is provided with an opening so that the light leakage is prevented by the light-shielding tube. Even if the light-shielding tube is movable due to recent zooming, etc. It was difficult to expect, and it was necessary to use a unique method to block light from the viewpoint of shutter design.

The present invention has been made in view of the above problems, and an object thereof is to provide a roller in which a shutter blade is pivotally supported between a shutter base plate and a cover plate. In addition, a drive pin for opening and closing the shutter blade is reciprocally movable within an opening formed in the shutter base plate and the cover plate, and is fitted into a slot provided in the shutter blade. In the above, it is possible to prevent light leakage from the opening and the slot with a simple structure.

[0005]

[Means and Actions for Solving the Problems]

 In order to achieve the above object, in the present invention, a shutter blade is pivotally supported on either one of the shutter base plate and the cover plate, and a drive for opening and closing the shutter blade. In the lens shutter for a camera, wherein a pin is reciprocally movable within openings provided in the shutter base plate and the cover plate, respectively, and is fitted into a slot provided in the shutter blade, in the camera lens shutter. A light shielding plate rotatably fitted to the drive pin is provided between the base plate and the cover plate.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A first embodiment of the present invention will be described with reference to FIGS. 1 is an exploded perspective view, FIG. 2 is a cross-sectional view of a main part of FIG. 1, and FIG. 3 is an enlarged plan view of the main part. Reference numeral 1 is a shutter base plate having an aperture 1a and an opening 1b, and pedestals 1c and 1d are integrally provided. Reference numeral 2 is a well-known moving magnet type motor, which has a drive pin 2a that reciprocally rotates, and is attached to the pedestals 1c and 1d of the shutter base plate 1 by screws 3 and 4. A cover plate 5 has an aperture 5a and an opening 5b, and pins 5c and 5d are planted. Reference numerals 6 and 7 denote shutter blades having holes 6a and 7a rotatably fitted in the pins 5c and 5d, respectively, and slots 6b and 7b loosely fitted into the drive pin 2a. Reference numeral 8 denotes a circular light shield plate having a hole 8a that is rotatably fitted to the drive pin 2a. In this embodiment, the light shield plate 8 is arranged between the shutter blades 6 and 7, as can be seen clearly in FIG. Therefore, the light incident from the upper side of the figure on the object side passes through the opening 1b of the shutter base plate 1 and the slot 6b of the shutter blade 6, but is prevented from traveling by the light shielding plate 8. If the light-shielding plate 8 does not exist, light passes from the part where the two slots 6b and 7b overlap and the drive pin 2a does not exist, as shown in the enlarged plan view of the main part of FIG. It will be. The light shield plate 8 may be arranged between the shutter base plate 1 and the shutter blades 6, or may be arranged between the shutter blades 7 and the cover plate 5. Further, a plurality of sheets may be arranged between these parts.

Second Embodiment A second embodiment will be described with reference to FIG. FIG. 4 is a sectional view similar to FIG. In this embodiment, the well-known opening / closing lever 9 is provided with a drive pin 9a, and the shutter base plate 1 is provided with pins 1e and 1f which fit into the holes 6a and 7a of the shutter blades 6 and 7, respectively. There is. The rest of the configuration and operation are the same as in the case of the first embodiment, so description will be omitted.

Third Embodiment A third embodiment will be described with reference to FIG. FIG. 5 is a sectional view of an essential part similar to FIGS. 2 and 4. In each of the first and second embodiments, different pins 5c and 5d are prepared for the shutter blades 6 and 7, respectively, and the shutter blades 6 and 7 are opened and closed with these pins as fulcrums. In the embodiment, the pin 5e planted on the cover plate 5 is used as a common fulcrum for opening and closing, and the positions of the holes 6a and 7a of the shutter blades 6 and 7 and the slots 6b and 7b are exchanged in FIG. It has been configured. Therefore, the well-known opening / closing lever 9 is provided with two drive pins 9b and 9c, and the shutter base plate 1 and the cover plate 5 are also provided with two openings 1g, 1h and 5f, 5g, respectively. The light blocking plates 10 and 11 are fitted to the drive pins 9b and 9c, respectively. In this embodiment, the light shielding plate 10 may be arranged between the shutter base plate 1 and the shutter blades 6, but it is not preferable to arrange the light shielding plate 11 between the shutter blades 7 and the cover plate 5. .

[0009]

[Effect of device]

 As described above, according to the present invention, the shutter blade is arranged between the shutter base plate and the cover plate, and the drive pin necessary for opening and closing the shutter blade is passed through the opening provided in the shutter base plate and the shutter blade is opened. In the lens shutter for a camera configured to be fitted in the slot, the cover plate is also provided with an opening in order to escape the tip end portion of the drive pin, and the light shield plate is fitted to the drive pin. The structure of the main plate surrounding the shutter blades can be made extremely thin, and there is no fear of light leakage. Further, as shown in FIGS. 2 and 3, when the light shielding plate is arranged between the shutter blades, even if the shutter blades operate in opposite directions, friction loss is less likely to occur and stable operation can be performed. The present invention can also be applied to the case where the number of shutter blades is one.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of an essential part of the first embodiment of the present invention.

FIG. 3 is an enlarged plan view of an essential part of the first embodiment of the present invention.

FIG. 4 is a sectional view showing a second embodiment of the present invention.

FIG. 5 is a sectional view showing a third embodiment of the present invention.

[Explanation of symbols]

 1 Shutter base plate 1a, 5a Aperture 1b, 1g, 1h, 5b, 5f, 5g Opening 1c, 1d Pedestal 1e, 1f, 5c, 5d, 5e Pin 2 Moving magnet type motor 2a, 9a, 9b, 9c Drive pin 3, 4 Screw 5 Cover plate 6,7 Shutter blade 6a, 7a, 8a Hole 6b, 7b Slot 8, 10, 11 Light shield 9 Open / close lever

Claims (4)

[Scope of utility model registration request] 1. A shutter blade is pivotally supported on either one of a shutter base plate and a cover plate between the shutter base plate and a cover plate, and a drive pin for opening and closing the shutter blade is provided between the shutter base plate and the cover plate. In a lens shutter for a camera, which is reciprocally movable in openings provided in the shutter blade and fitted in a slot provided in the shutter blade, the drive pin is provided between the shutter base plate and the cover plate. A light leakage prevention mechanism characterized in that a light-shielding plate that is rotatably fitted is provided on the light leakage prevention mechanism. 2. The light leakage prevention mechanism for a camera lens shutter according to claim 1, wherein the shutter blade is a plurality of sheets, and the light shielding plate is arranged between the shutter blades. 3. The camera lens shutter according to claim 1, wherein the light shielding plate is arranged between any one of the shutter base plate and the cover plate and the shutter blade. Light leakage prevention mechanism. 4. The lens shutter for a camera according to claim 1, wherein a plurality of drive pins are provided, each of which is fitted in a slot of another shutter blade and another light shielding plate. Light leakage prevention mechanism.