JP2001154240A - Optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that the shape of a bottom board becomes complicated or large although the holding part of a guide member for a movable optical element can be easily formed on the bottom board. SOLUTION: Relating to this optical device equipped with the movable optical elements 2 and 3 capable of moving in an optical axis direction with respect to the bottom board 10, at least either the guide member 8 guiding the movable optical element in the optical axis direction or a shake preventing member 9 preventing the shake of the movable optical element around the member 8 is held by a mask member 7 formed separately from the bottom board and fixed on the bottom board, and removing the harmful light of the optical system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device having a movable optical element movable in an optical axis direction, and more particularly to a zoom finder device mounted on a camera or the like.

[0002]

2. Description of the Related Art A finder device mounted on a zoom camera is configured such that a movable lens such as an objective lens is moved in conjunction with a photographing system so that an angle of view is obtained between the photographing system and the finder system. I have.

[0003] As an interlocking mechanism for enabling the correspondence of the angle of view between the photographing system and the viewfinder system, a cam ring provided on the lens barrel of the camera is provided directly on the movable lens of the viewfinder system. There is a type that transmits a driving force to a cam follower, and a type that transmits a driving force to a cam follower provided in a movable lens of a finder system via a cam plate interlocked with a zoom driving mechanism of a photographing system.

[0004] As a means for pressing a cam follower against a cam surface of a cam ring or a cam plate, many using an elastic member have been put to practical use.

[0005] On the other hand, the movable lens of the finder system (or a holding frame for holding the same) is normally guided by a guide bar extending in the optical axis direction. In many cases, it is blocked by a steady bar extending in the optical axis direction.

Further, a general finder device is configured with a fixed eyepiece system in which a prism for guiding light to an eyepiece behind the movable objective lens system composed of multiple groups is arranged. You.

Therefore, when a receiving portion for holding the guide bar or the anti-sway bar is provided on the finder base plate, conventionally, a lens holding frame which is slightly larger than the lens optical path is formed, and the respective bars are provided around the holding frame. While the fitting portions are provided, the respective bars (ends) are held by the front and rear wall surfaces of the finder base plate.

[0008]

However, in the above-described conventional bar holding structure, it is easy to form the holding portions for the two bars on the objective lens side, that is, on the front surface of the base plate, but the rear surface adjacent to the prism. On the side, there are the following problems due to restrictions on lens spacing and space.

(1) In order to secure a space for forming the bar holding portion, the size of the finder ground plate becomes large, and it is not possible to cope with downsizing of the apparatus.

(2) The shape of the bar holding portion becomes complicated, and the mold structure for molding the finder base plate becomes complicated, which leads to an increase in cost.

(3) The structure of the device becomes complicated, the workability of assembling becomes worse, and the time required for assembling becomes longer.

[0012]

According to a first aspect of the present invention, there is provided an optical apparatus having a movable optical element movable in an optical axis direction with respect to a ground plane. At least one of a guide member that guides in the optical axis direction and a vibration-preventing member that prevents the movable optical element from vibrating around the guide member is formed separately from the ground plate and fixed to the ground plate, thereby deteriorating the optical system. The mask member that removes light is held.

Preferably, the mask member is fixed at a position between the movable optical element and the prism or other fixed optical element in the ground plate.

[0014] Separating the mask portion, which has been conventionally formed integrally with the base plate, from the base plate as a separate part seems to increase the cost at a glance, but the shape of the base plate is simplified, which contributes to downsizing. At the same time, the mold structure is simplified, which is advantageous in terms of cost and accuracy.

In recent finder devices (optical devices), a ground plate in which a prism fixing portion and an eyepiece holding portion are integrated has become common due to a demand for further miniaturization, and a mask portion has been developed. It is no longer difficult to form a single unit. From this, it is very reasonable to separate the mask portion from the main plate and make it a separate part, and hold the guide member and the steady rest member by the mask member fixed to the main plate.

According to the second aspect of the present invention, in an optical device having a movable optical element movable in the optical axis direction with respect to the ground plane, a guide member for guiding the movable optical element in the optical axis direction and a guide member around the guide member are provided. At least one of the steadying members for preventing the movable optical element from being shaken is formed separately from the ground plate, fixed to the ground plate, and held by a cover member that covers the movable optical element.

Further, in the third invention of the present application, the movable optical element movable in the optical axis direction with respect to the ground plane, the prism fixed to the ground plane, and other fixed optical elements into which light passing through the movable optical element enters. In the optical device provided, at least one of a guide member that guides the movable optical element in the optical axis direction and a steadying member that prevents the movable optical element from swinging around the guide member is formed separately from the ground plate. The fixed optical element is fixed to the base plate and is held by a cover member that covers the fixed optical element.

Further, according to a fourth aspect of the present invention, in an optical apparatus provided with a finder optical system including a movable optical element movable in the optical axis direction with respect to the base plate, a guide member for guiding the movable optical element in the optical axis direction. A field frame member that is formed separately from the ground plate and is fixed to the ground plate, and is fixed to the ground plate, and determines the field of view of the finder optical system. To be held.

According to a fifth aspect of the present invention, in an optical device having a movable optical element movable in an optical axis direction with respect to a ground plane, a guide member for guiding the movable optical element in the optical axis direction and a guide member around the guide member are provided. A light blocking member that is formed separately from the ground plate and is fixed to the ground plate, and that blocks at least a part of the optical path of the optical system including the movable optical element. To be held.

According to the sixth aspect of the present invention, a movable optical element movable in the optical axis direction with respect to the ground plane, a prism fixed to the ground plane and bending the optical path of light passing through the movable optical element, and other fixed optics. An optical device provided with an element and at least one of a guide member that guides the movable optical element in the optical axis direction and a vibration-preventing member that prevents the movable optical element from swinging around the guide member. The fixed optical element is formed and fixed to the base plate, and is held by an element holding member that holds the fixed optical element.

As in the second to sixth aspects of the present invention, the guide member and the anti-sway member are held by members indispensable for constituting the optical device, thereby contributing to the simplification and downsizing of the shape of the base plate. At the same time, the mold structure is simplified, which is advantageous in terms of cost and accuracy.

[0022]

1 to 4 show the configuration of a finder device (optical device) according to an embodiment of the present invention.

First, in FIGS. 1 to 3, 1, 2, 3
Denotes objective lenses of a first group, a second group, and a third group, respectively. The first group objective lens 1 has a guide key shape for parallax adjustment integrally formed with the lens unit, and is fitted with play on an axis provided on the finder base plate 10 shown in FIG. The parallax adjustment is performed by eccentric movement with respect to and fixed.

Further, the second and third group objective lenses 2,
Reference numeral 3 denotes a finder cam plate interlocking with a zoom drive mechanism of a camera barrel (not shown), and cam follower pins 2a, 3
2A and 2B, and moves in the optical axis direction while being fitted to the guide bars 8, 8 'and the steadying bar 9 shown in FIGS. The two objective lenses 2 and 3 have fitting portions 12b and 13b with the guide bars 8 and 8 'and fitting portions 12c and 13c with the anti-sway bar 9, respectively. And may be formed integrally with each other to reduce the size.

The first to third lens groups 1 and 2
The luminous flux that has passed through 2 and 3 is removed from the harmful light by the mask member 7 (limited to the effective luminous flux),
And is guided to the eyepiece 4 via the reflection mirror 6 and reaches the eyes of the photographer.

As shown in FIG. 3, the finder base plate 10 has a front end wall portion 10a serving as a fixed portion of the first group objective lens 1, and a second group and a third group objective lens 2 behind it. , 3 movable spaces. A prism loading section 10c is formed behind the movable space.
Further, on both sides of the front end wall portion 10a, a holding portion 10 of a light emitting / receiving lens (not shown) serving as an autofocus element is provided.
b is formed.

A mirror holder 11 for holding the eyepiece 4 and the reflection mirror 6 is attached to one side of the prism loading section 10c in the finder base plate 10.

As described above, the finder base plate 10 of the present embodiment is miniaturized by integrating the functions of holding the optical elements and the like necessary for the finder device as much as possible. However, the shape becomes complicated by that much,
The mold structure for molding the finder base plate 10 also requires sliding on six sides.

Therefore, it is difficult to form a shape for holding the guide bars 8, 8 'and the anti-sway bar 9 on the finder ground plate 10, since the mold structure especially at the portion adjacent to the prism 5 becomes complicated. .

Therefore, in the present embodiment, as shown in FIG. 4, the mask member 7 is formed as a separate member from the finder base plate 10, and the mask member 7 is provided with the holding portions 7b and 7c for the guide bar 8 and the anti-sway bar 9. Is provided.

First, the mask member 7 is assembled and fixed in the finder base plate 10 while sliding vertically from above the finder base plate 10.

Next, the second and third group objective lenses 2,
3 is similarly assembled from above the finder base plate 10 to form a guide bar holding hole 10 formed in the front wall portion 10a.
d, and the guide bar 8 and the steady bar 9 are inserted into the finder base plate 10 through the steady hole 10e, and the fitting portions 13b, 13b of the lens holders 12, 13 are inserted.
The mask members 7 are made to reach the holding portions 7b and 7c while being engaged with 12c and 13c.

As for the guide bar 8 ', the guide bar 8' is inserted into the finder base plate 10 through the guide bar holding hole 10f formed in the front wall portion 10a, and the fitting portion 12b of each lens holder 12, 13 is inserted. And reaches a holding portion (not shown) formed in the finder base plate 10 at an intermediate position in the movable space. As described above, the incorporation of each component into the finder base plate 10 is completed.

As described above, in this embodiment, the guide bar 8 is attached to the mask member 7 which is a separate member from the finder ground plate 10.
In addition, by providing a function of holding the steady rest bar 9, the shape of the main plate is simplified to ensure good workability.

In the present embodiment, as described above,
Since each part is dropped into the same finder base plate 10 from the same direction with respect to the same reference receiving surface, the positional accuracy such as the coaxiality is accurately determined, and the assemblability is improved. Contribute.

It is also conceivable to integrate the mask member with one of the base plates by integrating the finder base plate with the fixed portion of the mask member as a boundary, but the optical axis deviation error when the two base plates are combined is considered. This embodiment is more likely to occur, and has many disadvantages such as leading to an increase in size by securing a space for a shaft for positioning the ground plates and a screw portion for fixing the ground plates or a margin for bonding, etc. It is advantageous.

In this embodiment, the case where the mask member 7 is provided with a function of holding a guide bar or the like has been described. May be provided with a holding function such as a guide bar on the prism protection cover or the finder upper surface cover fixed to the finder base plate 10 so as to cover the finder.

The field frame member fixed to the finder base plate to determine the finder field of view may have a holding function such as a guide bar.

Further, in the present embodiment, the finder device has been described, but the present invention can be applied to various optical devices having a movable optical element movable in the optical axis direction with respect to the base plate. In this case, a light-blocking member fixed to the base plate and blocking at least a part of the optical path of the optical system, or a prism holding member (element holding member) holding the prism and fixed to the base plate has a holding function such as a guide bar. You may let it.

[0040]

As described above, according to the present invention,
Since the holding function of the guide member or the steady rest member is formed as a separate member from the main plate, and is provided to the mask member, the cover member, and the field frame member fixed to the main plate, (1) the main plate itself is guided. Since there is no need to form a holding portion such as a bar, the size of the main plate can be reduced, and the size of the apparatus can be reduced. (2) The shape of the base plate can be simplified and molding can be easily performed. Further, the degree of freedom of the method of holding the guide member and the like is increased. (3) The number of components as an apparatus can be reduced, and assembling workability can be improved. And so on.

[Brief description of the drawings]

FIG. 1 is a perspective view showing optical components arranged in a finder device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration for holding the optical component by a guide bar or the like.

FIG. 3 is a perspective view showing a state in which each component is incorporated in a main plate constituting the finder device.

FIG. 4 is a perspective view of the base plate and a mask member.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st group objective lens 2 ... 2nd group objective lens 3 ... 3rd group objective lens 4 ... Eyepiece 5 ... Porro prism 6 ... Reflection mirror 7 ... Mask member 8 ... Guide bar 9 ... Steady bar 10a ... (Finder Front wall portion (of the base plate) 10b AF light receiving / receiving lens holding portion (of the viewfinder base plate) 10c ... Prism loading portion (of the viewfinder base plate) 10d ... Guide bar holding hole 10e ... Stabilizing bar holding hole 11 ... Mirror holder 2a, 3a ... Cam follower pin

Claims (7)

[Claims] 1. An optical device comprising a movable optical element movable in an optical axis direction with respect to a base plate, wherein a guide member for guiding the movable optical element in the optical axis direction and the movable optical element around the guide member are provided. Wherein at least one of the anti-vibration members is formed separately from the base plate, fixed to the base plate, and held by a mask member for removing harmful light of the optical system. apparatus. 2. A prism and other fixed optical elements into which light passing through the movable optical element is incident are fixed to the ground plate, and the mask member is formed by using the movable optical element and the movable optical element of the ground plate. The optical device according to claim 1, wherein the optical device is fixed at a position between the fixed optical element. 3. An optical device comprising a movable optical element movable in an optical axis direction with respect to a base plate, wherein a guide member for guiding the movable optical element in the optical axis direction and the movable optical element around the guide member are provided. An optical device, wherein at least one of the anti-vibration members is formed separately from the ground plate, fixed to the ground plate, and held by a cover member covering the movable optical element. 4. An optical device comprising: a movable optical element movable in an optical axis direction with respect to a ground plane; and a prism and other fixed optical elements fixed to the ground plane and bending an optical path of light passing through the movable optical element. In at least one of a guide member that guides the movable optical element in the optical axis direction and a vibration-preventing member that prevents the movable optical element from swinging around the guide member, is formed separately from the base plate. An optical device fixed to the base plate and held by a cover member covering the fixed optical element. 5. An optical device having a finder optical system including a movable optical element movable in an optical axis direction with respect to a ground plane, wherein a guide member for guiding the movable optical element in the optical axis direction and around the guide member are provided. At least one of the steady rest members for preventing the movable optical element from being shaken is formed separately from the ground plate and fixed to the ground plate, and is held by a field frame member that determines the field of view of the finder optical system. An optical device, characterized in that: 6. An optical device comprising a movable optical element movable in an optical axis direction with respect to a base plate, wherein a guide member for guiding the movable optical element in an optical axis direction and the movable optical element around the guide member are provided. At least one of the steadying members for preventing the shake is held separately from the ground plate and fixed to the ground plate, and is held by a light blocking member that blocks at least a part of an optical path of an optical system including the movable optical element. An optical device, wherein 7. A movable optical element movable in an optical axis direction with respect to a ground plane, and a prism and other fixed optical elements fixed to the ground plane and bending an optical path of light passing through the movable optical element. In the optical device, at least one of a guide member that guides the movable optical element in an optical axis direction and a shake prevention member that prevents the movable optical element from swinging around the guide member is formed separately from the base plate. And an optical device fixed to the ground plate and held by an element holding member for holding the fixed optical element.