JP2003330080A - Optical finder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical finder realizing the facilitation of assembling work, easily manufactured, and also realizing the facilitation of the exchange of a prism, and the facilitation of the removal of dust or the like intruding into space between the opposed surfaces of the prism. <P>SOLUTION: The optical finder FU is equipped with a prism optical system 30 constituted by arranging at least two prisms 31 and 32 so as to couple them in the vicinity of a subject image formed surface P in a finder case 10. It is equipped with a prism fixing member 40 energizing the optical system 30 in a specified direction in the case 10 and fixing it when attaching the optical system 30 to the case 10. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical finder provided with a prism optical system in which at least two prisms are arranged in a finder case so as to be connected in the vicinity of an image plane of a subject image.

[0002]

2. Description of the Related Art Generally, an optical finder of this type is disclosed in, for example, Japanese Patent Laid-Open No. 2001-27704.
The prism optical system that constitutes the finder optical system includes a first prism optical system and a second prism optical system, and an image plane is formed between the facing surfaces of the first prism optical system and the second prism optical system. Is set to exist. The reason why the prism is made into two bodies and the image plane is present between the facing surfaces is to dispose the field frame made of a thin plate member between the facing surfaces. At this time, good observation cannot be performed unless the imaging positions of the subject and the field frame do not match. Therefore, as described above, the image plane is set between the facing surfaces.

In an optical finder provided with a finder optical system including such a prism optical system, a bonding means using an adhesive is adopted as a means for holding the prism optical system at a predetermined position. That is, an adhesive such as an ultraviolet curable adhesive is applied between the prism and the finder case for accommodating the prism, and the adhesive is fixed between the two by curing the adhesive.

Further, in order to prevent dust from entering between the facing surfaces of the first prism optical system and the second prism optical system, an adhesive is applied to the periphery of the facing surfaces of the prisms or a finder is externally applied. Measures were taken such as reducing the gaps that might allow dust to enter the case.

[0005]

As described above, conventionally, in order to hold the prism optical system at a predetermined position of the finder case, the prism is adhered and fixed to the finder case with an adhesive. For this reason, a complicated work using a special bonding tool is required. As a result, there is a problem that the number of assembling steps is increased and the cost is increased.

Further, when an adhesive is applied to the periphery of the prism in order to prevent dust from entering, not only the number of assembling steps increases as in the above case, but also dust enters near the image forming surface after the adhesion. Is found,
The dust cannot be removed unless the bonded portion is peeled and disassembled. However, when the bonded portion is peeled and disassembled, it is almost impossible to reuse the prism or the like. Therefore, in the usual case, it must be disposed of. As a result, the cost becomes high.

The present invention has been made under such circumstances, and an object thereof is to provide an optical finder having the following advantages. (A) Assembly work is easy and production is easy. (B) It is possible to easily perform prism replacement work and the like, and it is possible to easily remove dust and the like that has entered between the facing surfaces of the prisms.

[0008]

In order to solve the above problems and achieve the object, the optical finder of the present invention has the following characteristic constitution. In addition, characteristic configurations other than the following will be clarified in the embodiments.

The optical finder of the present invention is an optical finder provided with a prism optical system in which at least two prisms are arranged in the finder case so as to be connected in the vicinity of the image plane of a subject image. When the system is installed in the finder case,
It is characterized in that a prism fixing member for biasing and fixing the prism optical system in a specific direction in the finder case is provided.

Since the optical finder does not require a bonding work using an adhesive, the assembling work is simple and the manufacture is easy.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 (a)
(B) is a figure which shows the outline | summary of the optical finder which concerns on 1st Embodiment of this invention, (a) is a figure which shows the schematic structure of the compact electronic camera to which the said optical finder was applied, (b) FIG. 3 is an external perspective view showing the external appearance of the optical finder.

As shown in FIGS. 1 (a) and 1 (b), this compact electronic camera 1 has a taking lens window 2 at the center of the front surface.
And a viewfinder front window 6, and a release button 8 on the upper surface. Inside the electronic camera 1, a light flux OA from a subject that has entered from the taking lens window 2 is reflected by a prism 3 in a substantially horizontal direction, and a subject image is formed on a light receiving surface of an image pickup device 5 via a taking optical system 4. A photographic lens unit LU for forming an image is housed. An optical finder unit FU is arranged above the photographing lens unit LU with a slight gap. A battery 9 is mounted on the side of the optical finder unit FU. A finder eyepiece window 7 for observing an image by the optical finder unit FU is arranged on the back surface of the electronic camera 1.

The optical finder unit FU has an objective lens group 21 to 2 described later inside the finder case 10.
Lens optical system 20 having 3 and first and second prisms 3
And a prism optical system 30 having 1 and 32.
The prism optical system 30 is arranged such that a first prism (Dach prism) 31 and a second prism 32 are connected in the vicinity of an image forming plane P of a subject image.

FIG. 2 is an exploded perspective view showing the internal structure of the optical finder unit FU. As shown in FIG. 2, the finder case 10 is composed of a case body 10A having an S-shaped recess and a flat case lid 10B.
The case body 10A is surrounded by side walls, and one end thereof is an opening end for mounting the prism optical system 30. The case lid 10B is a member that closes the opening end after the prism optical system 30 is mounted on the case body 10A.

A circular hole 11 facing the finder front window 6 is provided at the front end of the case body 10A, and a square hole 15 facing the finder eyepiece window 7 is provided at the rear end of the case body 10A. Has been. Further, the S-shaped recess is formed by connecting a housing portion 12 mainly for housing the lens optical system 20 and a housing portion 13 for housing the prism optical system 30. Note that reference numeral 14
Is a projecting edge portion accommodating groove for accommodating a projecting edge portion, which will be described later, formed in the peripheral portions of the facing surfaces of the first prism 31 and the second prism 32, respectively. On the bottom of the case body 10A, a positioning boss B1 is projected at a position corresponding to the first prism 31, and a positioning boss B2 is projected at a position corresponding to the second prism 32.

The lens optical system accommodating portion 12 accommodates a lens optical system 20 having a first objective lens 21, a second objective lens 22, and a third objective lens 23. The second
The objective lens 22 and the third objective lens 23 are lenses for zooming. Further, the prism optical system accommodating portion 13 accommodates a prism optical system 30 including first and second prisms 31 and 32. The first prism 31 is a so-called roof prism, and a roof portion 33 is joined to the rear portion of the reflecting surface of the first prism 31. An eyepiece lens 34 is arranged on the rear end surface of the second prism 32.

Thus, the light flux from the subject, that is, the observation light, which has entered from the front window 6 of the viewfinder, is the lens optical system 2.
It is incident on the first prism (Dach prism) 31 through 0. The observation light which is vertically inverted by the first prism (Dach prism) 31 is incident on the second prism 32. The observation light totally reflected twice by the second prism enters the eyepiece lens 34. The subject image obtained through the eyepiece lens 34 can be observed through the viewfinder eyepiece window 7 provided on the rear surface of the camera.

A prism fixing member 40 is attached to the prism optical system 30. The prism fixing member 40 is
When the first and second prisms 31, 32 are integrally fastened and the prism optical system 30 is mounted inside the finder case 10, the prism optical system 30 is urged in a specific direction inside the finder case 10. Then, it is for fixing. The specific configuration of the prism unit PU including the prism optical system 30 and the prism fixing member 40 will be described later. Lens optical system 20 and prism optical system 3
After 0 and 0 are accommodated in the case body 10A, the opening of the case body 10A is sealed by the case lid 10B. The case lid 10B is screwed to the opening of the case body 10A with, for example, a screw (not shown).

3A and 3B are views showing a concrete structure of the prism unit PU, FIG. 3A is a perspective view showing the unit PU in an exploded state, and FIG. 3B is a first and second prisms 31, 32.
3 is a perspective view showing only the vicinity of the facing surface of FIG. Figure 3
, The first prism 31 and the second prism 3
Reference numeral 2 denotes a pair of projecting edge portions 31a and 31b projecting in a direction intersecting with the optical axis at one end of each of the light flux passing surfaces facing each other.
And 32a and 32b respectively.

The facing surface of the first prism 31, that is, the peripheral portion of the opposing light flux passing surface (the peripheral portion of the prism effective range) is a flat surface for contact. Positioning projections (bosses) 31c and 31d are provided on the contacting flat surface.

Similarly, the opposing surface of the second prism 32, that is, the peripheral portion of the opposing light beam passing surface (peripheral portion of the prism effective range) is also a flat surface for contact. Recesses (holes) 32c, 32d for positioning by fitting with the above-mentioned protrusions 31c, 31d at portions corresponding to the above-mentioned protrusions (bosses) 31c, 31d on the plane for contact.
Is provided.

First prism 31 and second prism 32
Is arranged so that the contacting planes face each other with a gap G therebetween, and the optical design is made so that the image forming plane P is formed in the gap G. A field frame 50 for determining the field shape is inserted and arranged in the gap G. The convex portion 31c in the peripheral portion 50a of the field frame 50,
Positioning through holes 50c and 50d are provided at locations corresponding to 31d.

Thus, when assembling the prism, the first
The convex portions (bosses) 31c and 31d provided on the contacting flat surface of the prism 31 of FIG.
After penetrating d, the first prism 31, the field frame 50, and the second prism are fitted by fitting into the recesses (holes) 32c and 32d provided in the plane for contact of the second prism 32. The three with 32 are simultaneously positioned and integrated with each other. The prism fixing member 40 is attached to the joint portion of the first and second prisms 31 and 32 integrated in this way. In addition, the first prism 31
A bottom surface of the second prism 32 has a positioning hole Q1 corresponding to the positioning boss B1. A bottom surface of the second prism 32 has a positioning hole Q2 corresponding to the positioning boss B2.

FIG. 4 is a perspective view showing the structure of the prism fixing member 40 in detail. As shown in FIG. 4, the prism fixing member 40 is composed of a leaf spring formed of an elastic member such as metal or resin, and has a shape similar to a quadruped as shown. Attachment parts 41 and 42 having a shape corresponding to the front foot and the rear foot, respectively, are provided near the front end portion and the rear end portion of the strip-shaped main column portion 40A having a shape corresponding to the spine. ing.

The mounting portions 41 and 42 respectively have a pair of leg portions 41a, 41b and leg portions 42a, 42b bent in a U shape. The pair of leg portions 41a, 41b and the leg portions 42a, 42b are fitted into the pair of projecting edge portions 31a, 31b and 32a, 32b provided on the first and second prisms 31, 32, respectively. At this time, the protrusions 31a, 31b and 32a,
It is set so as to be biased in the direction of arrow X so that 32b can be clamped with a predetermined pressure. Therefore, the leg portion 41
The a and 41b and the leg portions 42a and 42b act as a pair of clip mechanisms for elastically sandwiching the pair of projecting edge portions 31a and 32a, 31b and 32b, respectively.

Thus, the mounting portion 4 in this embodiment
Reference numerals 1 and 42 denote fastening means T for biasing the light flux passing surfaces of the two prisms 31 and 32 of the prism optical system 30 which face each other toward each other and fastening the two prisms 31 and 32 integrally. Contains.

When the prism optical system 30 is mounted on the other part of the prism fixing member 40 inside the finder case 10, the prism optical system 30 comes into contact with the inside of the case 10 and is elastically deformed. Of the two types of biasing portions 4 for respectively biasing each of the cases 10 in two specific directions.
3 and 44 and 45. With the specific direction,
This is a direction to cancel the mounting margin provided for housing the prism optical system 30 in the finder case 10.

The biasing portion 43 is a strip-shaped main pillar portion 4
The abutment portion 43 is a spring piece formed by extending the front end of 0A in a dogleg shape, and is provided on the mountain-shaped bent top.
f is set to be biased in the direction of arrow Y.

The biasing portions 44 and 45 are strip-shaped spring portion pieces formed so as to cross the main pillar portion 40A in a cross shape, and abutting portions 44f and 45f provided at both ends thereof have an arrow Z. It is set to be biased in the direction of.

5A and 5B show the prism fixing member 4
It is a figure which shows the effect | action of 0. The mounting portions 41, 42 of the prism fixing member 40 are provided with a pair of projecting edge portions 31a, 31b and 32a, 32 provided on the first and second prisms 31, 32.
The prism fixing member 40 is attached to the optical system 30 by being fitted into b. Then, the pair of projecting edge portions 31a, 31b and 32a, 32b form the leg portions 41a, 41b of the mounting portion 41 and the leg portion 42 of the mounting portion 42.
The two prisms 31 and 32 are integrally fastened because they are sandwiched by the sandwiching force XF by a and 42b.

At this time, the abutting planes of the prisms 31 and 32 are in close contact with each other so that no gap is formed over the entire periphery of the field frame 50. Therefore, it is possible to prevent dust and the like from entering between the facing surfaces of the prisms 31 and 32 from the outside.

First and second parts integrally fastened as described above
When the prisms 31 and 32 of No. 3 are inserted into the finder case 10, the contact portion 43f of the urging portion 43 is inserted into the case body 1
The inner surface of the side wall of 0A is elastically deformed, and the repulsive force acts as an urging force YF to urge the prism optical system 30 toward the inner surface of the opposite side wall of the case. As a result, the prism optical system 3
0 rotates about the positioning hole Q1 engaged with the positioning boss B1 as a center of rotation, and the abutting surface of the positioning hole Q2, which is an elongated hole engaged with the positioning boss B2, is pressed against the positioning boss B2. As a result, the prism optical system 30 is stably positioned at a predetermined position on the case body 10A.

The opening of the case body 10A is connected to the case lid 1.
When sealed with 0B, the contact portion 44f of the biasing portion 44 and the contact portion 45f of the biasing portion 45 contact the inner surface of the case lid 10A and elastically deform, and the repulsive force becomes the biasing force ZF and the prism. The optical system 30 is biased toward the inside of the case body. as a result,
The prism optical system 30 is pressed and held against the bottom of the case body 10A.

(Characteristics of the Embodiment) [1] The optical finder FU shown in the embodiment has at least two prisms 3 in the finder case 10.
In an optical finder FU provided with a prism optical system 30 in which 1 and 32 are arranged so as to be connected near the image forming plane P of a subject image, when the prism optical system 30 is mounted in the finder case 10. A prism fixing member 40 for urging and fixing the prism optical system 30 in a specific direction inside the finder case 10 is provided.

Since the optical finder FU does not require a bonding work using an adhesive, the assembling work is easy.

[2] The optical finder FU shown in the embodiment is the optical finder according to the above [1],
The prism fixing member 40 is formed of an elastic member (a leaf spring or the like), has mounting portions 41 and 42 that can be attached to the prism optical system 30 in one portion, and the prism optical system in another portion. When the finder case 10 is mounted in the finder case 10, the urging portions 43, 44, 45 contact the inside of the case 10 and elastically deform to urge the prism optical system 30 in a specific direction in the case 10. It is characterized by having.

In the optical finder FU, the prism optical system 30 can be detachably mounted in the finder case 10 by the prism fixing member 40 made of an elastic member. Therefore, it is possible to easily perform the prism replacement work and the like, and it is easy to remove dust and the like that have entered between the facing surfaces of the prisms.

[3] The optical finder FU shown in the embodiment is the optical finder described in [1] or [2] above, and the prism optical system 30 is placed in the finder case 10 in the specific direction. It is characterized in that it is in the direction of canceling the mounting margin provided for housing.

[4] The optical finder FU shown in the embodiment is the optical finder described in [2] above.
The finder case 10 has a case body 10A surrounded by side walls and one end serving as an opening end for mounting the prism optical system, and the prism optical system 30 connects the opening end of the case body 10A. A case lid 10B that closes after being attached, and the biasing portions 43, 4
Reference numerals 4 and 45 respectively contact the inner surface of the side wall of the case body 10A and the inner surface of the case cover body 10B to elastically deform them, and two types of urging portions 43 for urging the prism optical system 30 in two specific directions. , And 44, 45 are included.

[5] The optical finder FU shown in the embodiment is the optical finder described in [1], [2] or [4], and the prism fixing member 40 is the prism optical system 30. The two prisms 3 in
The two prisms 31, 32 are urged in the directions in which the light flux passing surfaces of the two prisms 1, 32 facing each other approach each other.
It is characterized by further comprising a fastening means T for fastening the 32 together.

In the optical finder FU, the two prisms 3 are fixed by the single prism fixing member 40.
1 and 32 can be integrated and the prism optical system 30 can be fixed to the finder case 10 at once.

[6] The optical finder FU shown in the embodiment is the optical finder described in [2] or [4], and the mounting portions 41 and 42 are the optical finder of the prism optical system 30. It is characterized by including fastening means T for fastening the two prisms 31 and 32 integrally by urging the opposing light flux passing surfaces of the two prisms 31 and 32 toward each other.

In the optical finder FU, when the mounting portions 41 and 42 of the prism fixing member 40 are mounted on the prism optical system 30, the two prisms 31 and 3 are used.
The two fastening operations are performed at the same time. Therefore, the fastening means T
Therefore, the prism fixing member 40 has a simple structure.

[7] The optical finder FU shown in the embodiment is the optical finder according to the above [5] or [6], and the two prisms 31 and 32 have light beam passage surfaces facing each other. At one end of each of the protrusions (31a, 31b and 32a, 32) protruding in a direction intersecting the optical axis.
b), and the fastening means T comprises a clip mechanism for elastically sandwiching the projecting edge portions (31a and 32a, 31b and 32b).

In the above optical finder FU, the projecting edge portions (31a and 3a) are provided by the fastening means T composed of a clip mechanism.
The two prisms 31 and 32 are easily and accurately integrated by simply sandwiching 2a, 31b and 32b).

[8] The optical finder FU shown in the embodiment is the optical finder according to the above [5] or [6], and the two prisms 31 and 32 have light beam passage surfaces facing each other. At one end of each, a pair of projecting edge portions 31a, 31b and 32a, 3 projecting in a direction intersecting the optical axis.
2b, and the fastening means T comprises a pair of clip mechanisms for elastically sandwiching the pair of projecting edge portions 31a and 32a, 31b and 32b, respectively.

In the above optical finder, the pair of projecting edge portions 31a, 31b and 32a, 32b formed on both sides of the two prisms 31, 32 are clamped by the fastening means T consisting of a pair of clip mechanisms. , The two prisms are fastened in a stable form.

[9] The optical finder FU shown in the embodiment is the optical finder according to any one of the above [5] to [8], and the two prisms 31,
The relevant prism 3
The present invention is characterized in that positioning means (such as fitting of the concavo-convex portions 31c, 31d, 32c, and 32d) for performing mutual positioning of 1 and 32 is provided.

In the optical finder FU, the two prisms 31 and 32 are easily and accurately positioned by the positioning means, which facilitates the assembly work.

[10] The optical finder FU shown in the embodiment is the optical finder described in [9] above, in which the visual field shape is formed between the light flux passing surfaces of the two prisms 31 and 32 which face each other. A field frame 50 for determining the position is further arranged, and the positioning means (concave and convex portions 31c, 31)
d, 32c, 32d, etc.), the prism 3
It is characterized in that it is provided so that the mutual positioning of 1 and 32 and the mounting position of the field frame 50 are commonly performed.

In the optical finder FU, the positioning of the prisms 31 and 32 and the mounting position of the field frame 50 are commonly performed by a single positioning means. Therefore, the assembly is easy, and the field frame 5
A position shift of 0 is prevented.

(Modification) The optical finder shown in the embodiment includes the following modifications. A fastening means T for fastening the two prisms 31 and 32 integrally is provided separately from a mounting portion for mounting the prism fixing member 40 to the prism optical system 30.・ Those with four or more biasing parts.・ A projecting edge is provided only in one place.

[0053]

According to the present invention, it is possible to provide an optical finder having the following operational effects.

(A) Since no bonding work using an adhesive is required, the assembling work is simple and the manufacture is easy.

(B) With the prism fixing member made of an elastic member, the prism optical system can be detachably mounted in the finder case, so that the prism replacement work can be easily performed and the prisms face each other. It is easy to remove dust that has entered between the surfaces.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of an optical viewfinder according to a first embodiment of the present invention, FIG. 1A is a diagram showing a schematic configuration of a compact electronic camera to which the optical viewfinder is applied,
(B) is an external perspective view showing the external appearance of the optical finder.

FIG. 2 is an exploded perspective view showing the internal structure of the optical finder unit according to the first embodiment of the present invention.

3A and 3B are views showing a specific configuration of a prism unit according to the first embodiment of the present invention, FIG. 3A is a perspective view showing the unit in an exploded manner, and FIG. The perspective view which cuts out and shows only the opposing surface vicinity.

FIG. 4 is a perspective view showing in detail the configuration of a prism fixing member according to the first embodiment of the present invention.

5A and 5B are views showing the operation of the prism fixing member according to the first embodiment of the present invention.

[Explanation of symbols]

LU ... Shooting lens unit FU ... Optical finder unit PU ... Prism unit T ... Fastening means 10 ... Finder case 10A ... Case body 10B ... case lid 20 ... Lens optical system 21 to 23 ... First to third objective lenses 30 ... Prism optical system 31 ... First prism (Dach prism) 32 ... Second prism 40 ... Prism fixing member 41, 42 ... Mounting part 43, 44, 45 ... Energizing section 50 ... Field of view frame

Front page continuation (51) Int.Cl. ⁷ identification code FI theme code (reference) G02B 7/18 G03B 13/06 G03B 13/06 G02B 7/18 A

Claims (10)

[Claims] 1. An optical finder provided with a prism optical system in which at least two prisms are arranged so as to be connected in the vicinity of an image plane of a subject image in the finder case, wherein the prism optical system is the finder case. An optical finder provided with a prism fixing member for urging and fixing the prism optical system in a specific direction inside the finder case when mounted inside. 2. The prism fixing member is formed of an elastic member, and has a mounting portion that can be mounted to the prism optical system in one part, and the prism optical system in the other part in the finder case. When mounted on, the case has an urging portion that abuts the inside of the case and elastically deforms, and urges the prism optical system in a specific direction inside the case. Optical viewfinder. 3. The optical finder according to claim 1, wherein the specific direction is a direction in which a mounting margin provided for housing the prism optical system in the finder case is canceled. 4. The finder case is surrounded by a side wall, one end of which is an opening end for mounting the prism optical system, and the opening end of the case main body is provided with the prism optical system. And a case lid that closes after being attached, and the urging portion is elastically deformed by abutting on the inner surface of the side wall of the case body and the inner surface of the case lid, respectively. The optical viewfinder according to claim 2, further comprising two types of biasing portions that bias in a specific direction. 5. The fastening means for integrally fastening the two prisms by urging the prism fixing member in such a direction that the light flux passage surfaces of the two prisms of the prism optical system facing each other are brought closer to each other. The optical finder according to claim 1, 2 or 4, further comprising means. 6. The fastening means for fastening the two prisms integrally by urging the mounting portion in such a direction that the light flux passage surfaces of the two prisms of the prism optical system that face each other are brought closer to each other. The optical finder according to claim 2, further comprising: 7. The two prisms each have a projecting edge portion projecting in a direction intersecting the optical axis at one end of each of the two prisms having opposing light beam passage surfaces, and the fastening means is configured such that the projecting edge portions are joined to each other. 7. The optical finder according to claim 5 or 6, comprising a clip mechanism for elastically sandwiching. 8. The two prisms respectively have a pair of projecting edge portions projecting in a direction intersecting the optical axis at one end of each of the two prisms having opposing light beam passage surfaces, and the fastening means comprises the pair of projecting portions. 7. The optical finder according to claim 5, comprising a pair of clip mechanisms for elastically sandwiching the projecting edge portions. 9. The positioning means for positioning the prisms with each other is provided in the peripheral portions of the light flux passage surfaces of the two prisms which face each other. Optical finder described in. 10. A visual field frame for determining a visual field shape is further arranged between mutually facing light flux passing surfaces of the two prisms, and the positioning means positions the prisms relative to each other and a mounting position of the visual field frame. 10. The optical finder according to claim 9, wherein the optical finder is provided so as to perform common positioning.