JP2002082370A - Finder system and optical equipment using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a finder system and optical equipment with which the occurrence of ghosts and flares at the inside of a finder visual field and in the vicinity of a visual field is surely prevented. SOLUTION: In the finder system, having a visual field frame for regulate the finder visual field and an eyepiece to guide luminous flux from a finder image formed in the visual field frame or in the vicinity of it to the eyeball of an observer, the eyepiece possesses a positive lens, which is moved on a finder optical axis with a negative lens, in the order starting from the side of the visual field frame in order and by which finder diopter is adjusted; and the negative lens is provided with a first light-shielding means for shielding the peripheral luminous flux of a finder luminous flux in the short-side direction and the positive lens is provided with a second light-shielding means for shielding the peripheral luminous flux of the finder luminous flux in a long side direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finder system having a diopter adjustment mechanism and an optical apparatus using the same.
For example, it is suitable for optical devices such as cameras, still cameras, video cameras, and digital cameras.

[0002]

2. Description of the Related Art Conventionally, a finder system of many optical apparatuses is provided with a diopter adjustment mechanism for observing a finder image in accordance with the diopter of an observer.

For example, Japanese Patent Application Laid-Open No. 06-075273 or Japanese Patent Application Laid-Open No. 07-306449 propose a camera with a finder diopter adjustment function. The eyepieces of the proposed viewfinder diopter adjustment mechanism are arranged in the order of a concave lens (negative lens), a convex lens (positive lens), and a cover glass from the pentaprism side, and the convex lens is configured to be movable in the direction of the viewfinder optical axis. The convex frame is moved by moving the moving frame in the direction of the viewfinder optical axis, and the diopter of the viewfinder is varied to adjust the diopter. In addition, both the concave lens and the convex lens have an aspect ratio of 2: 3.
The lens effective range in the vertical direction is cut in accordance with the viewfinder field size which is set horizontally so as to be equivalent to the aperture size of, and is set to be horizontally long. further,
Recently, a camera has been commercialized in which the convex lens is further elongated horizontally, a flat portion is provided outside the lens effective range, and the moving function unit of the moving frame is integrally provided to eliminate the moving frame.

[0004]

In the above-mentioned prior art, the effective lens area in the vertical direction of the movable concave lens and convex lens is cut into a horizontally long shape, and a non-lens portion is provided in the horizontal direction of the convex lens. . For this reason, when the observer shakes his / her eyes slightly up, down, left and right at the eye point position and looks into the finder, diffused light (noise light) from inside and outside of the finder effective light beam is reflected on the upper and lower end surfaces of the concave lens and the convex lens, and is within the finder field. And enters near the outside of the visual field, and as a result, a ghost occurs. In addition, diffused light reflected on the left and right end surfaces of the concave lens and diffused light transmitted through the concave lens and directly transmitted through the non-lens portions, which are flat portions on the left and right sides of the convex lens, enter the vicinity outside the finder field and become ghosts and flares. To prevent ghost and flare from occurring, the effective range of concave and convex lenses is increased so that the diffused light from inside and outside the finder does not reflect or pass through the non-lens part. There was a problem that would cause an increase in size.

An object of the present invention is to provide a small finder system which prevents generation of ghost and flare due to the incidence of diffused light from inside and outside the finder effective light beam without increasing the effective diameter of the eyepiece, and to provide an optical apparatus using the same. Aim.

[0006]

The finder system according to the first aspect of the present invention is for guiding a light beam from a finder image formed in or near the field frame for restricting the finder visual field to an observer's eyeball. In the viewfinder system having the eyepiece lens, the eyepiece lens has a negative lens and a positive lens that moves on the finder optical axis in order from the field frame side to adjust the finder diopter. The first lens is provided with a first light blocking means for blocking peripheral light beams in the side direction, and the second lens is provided in the positive lens with a second light blocking means for blocking peripheral light beams in the long side direction of the finder light beam.

According to a second aspect of the present invention, there is provided a finder system which includes a field frame for regulating a finder field, an image inverting means for converting a finder image formed in or near the field frame into an erect image, and a light beam from the image inverting means. In a finder system having an eyepiece for guiding the eyeball of the observer, the eyepiece moves on the negative lens and the finder optical axis in order from the field frame side, and has a positive lens for adjusting the finder diopter, The negative lens is provided with first light blocking means for blocking peripheral light beams in the short side direction of the finder light beam, and the positive lens is provided with second light blocking means for blocking peripheral light beams in the long side direction of the finder light beam. I have.

According to a third aspect of the present invention, there is provided a finder system comprising: an objective lens for forming a finder image in or near the field frame for regulating a finder field; and an eyepiece for guiding a light beam from the finder image to an eyeball of an observer. In the viewfinder system having a negative lens, the eyepiece moves in order from the field frame side on the negative lens and the finder optical axis, and has a positive lens for adjusting the finder diopter. The first lens is provided with a first light-blocking means for blocking peripheral light beams, and the second lens is provided with a second light-shielding means for blocking peripheral light beams in the long side direction of the finder light beam in the positive lens.

A fourth aspect of the present invention is characterized in that, in the first, second or third aspect of the present invention, the first light shielding means is provided on the incident surface side of the negative lens.

A fifth aspect of the present invention is characterized in that, in the first, second, or third aspect of the present invention, the second light shielding means is provided on the exit surface side of the positive lens.

The invention of claim 6 is the invention of claim 1, 2, 3, or 5.
7. The invention according to claim 1, wherein said second light-shielding means shields a peripheral light beam in a range larger than a finder effective light beam and smaller than a lens effective range of said positive lens. In the invention according to any one of the first to third aspects, the first and second light shielding means are made of a light shielding sheet material.

The invention of claim 8 is characterized in that, in the invention of claim 7, the light-shielding sheet material is adhered and fixed to the negative lens and the positive lens.

A ninth aspect of the present invention is characterized in that, in the invention of any one of the first to sixth aspects, the first and second light shielding means are made of a light shielding paint.

A tenth aspect of the present invention is characterized in that, in the ninth aspect of the present invention, the light-shielding paint is applied and printed on the negative lens and the positive lens.

According to an eleventh aspect of the present invention, there is provided an optical apparatus including the finder system according to any one of the first to tenth aspects.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1, 2 and 3 show the configuration of a first embodiment of a finder device (finder system) provided in a single-lens reflex camera (optical apparatus) according to the present invention. The main part schematic diagram is shown. FIG. 1 is a perspective view of the finder device, FIG. 2 is a transverse sectional view of an eyepiece portion of the finder device, and FIG. 3 is a longitudinal sectional view of an eyepiece portion of the finder device.

In these figures, reference numeral 1 denotes a field frame, which is an observation mirror (quick return mirror) in which a subject image transmitted through a photographic lens (not shown) is set at an angle of 45 degrees with respect to an optical axis (not shown). The size of the field of view of the finder light beam that enters the finder optical system via the reflection of light is limited. Reference numeral 2 denotes an image reversing means, which is formed of a pentaprism that bends the finder light beam transmitted through the field frame 1 in the direction of the eyeball of the photographer and turns the subject image into an erect image. Reference numeral 3 denotes a negative lens (concave lens), which is bonded and fixed to an eyepiece lens holder (not shown). Reference numeral 4 denotes a positive lens (convex lens) which is movable in the direction of the finder optical axis La. The convex lens 4 has a shaft (guide shaft) in an eyepiece holder (not shown) fitted with a hole 4a of a convex portion 4b integrally formed outside the effective portion of the left lens of the convex lens 4 so that the finder optical axis La direction. It is configured to slide.
The mechanism for moving the convex lens 5 in the direction of the finder optical axis La is not limited to this method, and may be any method.
The diopter (finder diopter) can be adjusted by moving the convex lens 4 in the direction of the finder optical axis La, and the diopter adjustment range is set to ± 1.5 deopters around -1.0 deopters. Reference numeral 5 denotes a cover glass which is bonded and fixed to an eyepiece lens holder (not shown) to prevent dust and dust from entering from the eyepiece E side or to protect the convex lens 4. Reference numeral 6 denotes a first light-shielding mask (upper and lower light-shielding masks), which is made of a black mylar sheet having a plate thickness of 0.1 mm and is adhered and fixed to the surface of the concave lens 3 on the pentaprism 2 side or fixed with a slight space therebetween. The vertical direction (short side direction) of the finder light beam is restricted.
Reference numeral 7 denotes a second light-shielding mask (right and left light-shielding mask), which is formed of a black mylar sheet having a thickness of 0.1 mm and is adhered and fixed to the surface of the convex lens 4 on the cover glass 5 side or fixed with a slight space therebetween. The left-right direction (long side direction) of the finder light beam is restricted. In this embodiment, the upper and lower light-shielding masks 6 and the left and right light-shielding masks 7 are each composed of a single member having a rectangular shape in consideration of the workability of assembling. The left and right light shielding mask 7 may be constituted by two members that shield the light beam in the left and right direction in the finder light beam.

The finder optical system may include another lens in addition to the concave lens 3 and the convex lens 4.

FIG. 2 is a view showing the luminous flux in the finder left-right direction (long side direction) at the position where the movable convex lens 4 is moved to the concave lens 3 side most (diopter-2.5 deopter position). In FIG. 2, E denotes an eye point that is the position of the eyeball of the observer, A denotes a finder effective light flux, and B denotes a finder light field margin when the eyeball at the eyepoint position E is swung right and left. It is. The luminous flux B is restricted by the right and left light-shielding masks 7 that shield light to the lens effective range so as to securely cover a flat portion outside the lens effective portion of the convex lens 4.

FIG. 3 is a view showing the luminous flux in the finder vertical direction (short side direction) at the position where the movable convex lens 4 is moved to the concave lens 3 side most (diopter -2.5 deopter position). Similarly to FIG. 2, E is an eye point which is the position of the eyeball of the observer, A shows the finder effective light flux, and B shows the finder visual field margin when the eyeball is swung right and left at the eye point position. It is a luminous flux.
The light flux B is restricted by the upper and lower light shielding masks 6.

In the above configuration, when the left and right light shielding masks 7 and the upper and lower light shielding masks 6 are not provided, for example, diffused light (noise light) almost parallel to the finder optical axis La such as light flux C shown in FIG. Is incident, the diffused light Ca is transmitted through the flat portion outside the lens effective portion of the concave lens 3 and the convex lens 4 and enters the outer periphery on the right side of the finder field at the eye point position E. As a result, the outer periphery of the field of view becomes flare-like like a white haze, and an unsightly finder image is observed. Further, for example, when diffused light enters from the vicinity of the center of the finder optical axis La to the periphery like the light flux D, the light is reflected on the left end surface of the concave lens 3 and transmits through the convex lens 4 to be near the left side of the finder field at the eye point position E. If the diffused light Da enters and there is a strong light source in the same optical path as the light flux D, a ghost that shines sharply near the left side of the viewfinder field of view will cause an unsightly viewfinder image. In addition, for example, as shown in FIG.
a when the diffused light is incident substantially parallel to the
Is reflected on the upper end face 4C of the lens, and the diffused light Fa enters near the upper side of the finder field at the eye point position E, and when there is a light source of strong light in the same optical path as the light beam F as in the case of the light beam D, near the left side of the finder field of view. A ghost that glows sharply occurs, resulting in an unsightly viewfinder image. Although the diffused lights C, D, and F are described using only one light flux in one direction, they are diffused lights generated in all four directions (up, down, left, right).

Even when the left and right light-shielding masks 7 and the upper and lower light-shielding masks 6 are not provided, it is possible to prevent ghost and flare by increasing the finder visual field allowance. It is necessary to enlarge the effective lens portions of the concave lens 3 and the convex lens 4 in both the upper, lower, left and right directions, which leads to an increase in the size of the entire finder system and the camera used therefor. Further, the convex lens 4 must be enlarged also in the lens thickness direction, so that the effective lens portion cannot be increased. Therefore, the amount of movement of the convex lens 4 in the direction of the finder optical axis La is reduced, and the diopter adjustment range is also reduced. I will invite you. On the other hand, in the present embodiment, by providing the left and right light-shielding masks 7 and the upper and lower light-shielding masks 6, the incidence of the diffused lights C and D can be restricted by the light-shielded masks 7, and the incidence of the diffused light F can be reduced. Since the light can be restricted by the light-shielding mask 6 and diffused light can be prevented from entering the eye point E, ghosts and flares that occur in and around the finder visual field as well as in the finder visual field can be prevented. Can be easily reduced in size.

Since the convex lens 4 is provided with the slide shaft hole 4a integrally, a plane portion outside the lens effective portion in the left-right (long side) direction is located inside (the finder optical axis side) from the left and right end surfaces of the concave lens 3. I'm approaching For this reason, if the left and right light shielding mask 7 shields a portion of the convex lens 4 close to the plane portion outside the lens effective portion, the incidence of diffused light can be more reliably prevented. In addition, since the viewfinder margin can be set to the maximum, the right and left light shielding masks 7 are provided on the exit side (the cover glass 5 side) of the convex lens 4 having a small effective lens diameter.

The concave lens 3 has substantially the same size at the upper and lower end surfaces of the convex lens 4 in order to reduce the size in the height direction. For this reason, the upper and lower shading masks 6 can more reliably prevent the diffused light from entering by blocking the portion near the upper and lower end surfaces of the concave lens 3 where the reflected light of the diffused light is incident more toward the center of the eye point E. Since it is possible, it is provided on the incident surface side of the concave lens 3 (the pentaprism 2 side).

In the above embodiment, the light-shielding mask has a plate thickness.
Although a 0.1 mm black mylar sheet is used, similar effects can be obtained by coating and printing a light-shielding member or a light-shielding paint.

It should be noted that some effects can be obtained even if the left and right light shielding masks 7 are provided on the incident side of the convex lens 4. Further, even if the upper and lower light shielding masks 6 are provided on the emission side of the concave lens 3, a certain effect can be obtained.

FIG. 4 is a schematic view of a main part of a second embodiment in which the finder device (finder system) of the present invention is applied to an optical device such as a video camera, a digital camera, a lens shutter camera and the like.

In the drawing, OL denotes a variable-magnification objective lens having two lenses, a first lens unit L1 having a negative refractive power and a second lens unit L2 having a positive refractive power, which are movable on the optical axis. I have.

When the objective lens OL has a single focal length, the first unit L1 and the second unit L2 are fixed.

Reference numeral 14 denotes an image inverting optical system for an erect erect image, which comprises a prism member. Reference numeral 15 denotes a field lens. Reference numeral 16 denotes a field frame that limits the viewfinder field.

A finder image of an inverted real image formed by the objective lens OL is formed on or near a field frame 16 via an image inverting optical system 14 and a field lens 15.

6 is a first light-shielding mask (upper and lower light-shielding masks), 3 is a concave lens, 4 is a convex lens, and 7 is a second light-shielding mask (left and right light-shielding masks).
The configurations and operations of 4, 6, and 7 are the same as those of the first embodiment in FIG.

The concave lens 3 and the convex lens 4 constitute an eyepiece, and the finder image formed on the field frame 16 or its vicinity is observed from the eye point E.

In this embodiment, the objective lens OL,
The image reversing means 14 and the field lens 15 are omitted, a display element such as a liquid crystal panel is arranged on or near the field frame 16, and a finder image electrically displayed on the display element is observed with an eyepiece. Is also good.

Next, an embodiment of a video camera (optical apparatus) using a finder system according to the present invention will be described with reference to FIG.

In FIG. 5, reference numeral 20 denotes a video camera body,
Reference numeral 21 denotes a photographing optical system constituted by a zoom lens, 2
Reference numeral 2 denotes a CCD for receiving a subject image by the photographing optical system 21
, A recording unit for recording a subject image received by the imaging device 22, and a finder system 24 for observing the subject image displayed on a display element (not shown). The display element includes a liquid crystal panel or the like, and displays a subject image formed on the imaging element 22. Reference numeral 25 denotes a liquid crystal display panel having a function equivalent to that of the finder.

By applying the finder system of the present invention to an optical device such as a video camera, a compact optical device having high optical performance is realized.

[0038]

According to the present invention, by specifying each element as described above, it is possible to prevent the occurrence of ghost and flare due to the incidence of diffused light from inside and outside the finder effective light beam without increasing the effective diameter of the eyepiece. Finder system and an optical device using the same.

[Brief description of the drawings]

FIG. 1 is a perspective view of a finder system provided in an optical apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of an eyepiece part of the finder device of FIG. 1;

FIG. 3 is a longitudinal sectional view of an eyepiece of the finder device of FIG. 1;

FIG. 4 is a schematic diagram of a main part of a finder system according to a second embodiment of the present invention.

FIG. 5 is a schematic view of a main part of the optical apparatus of the present invention.

[Explanation of symbols]

 Reference Signs List 1 field frame 2 pentaprism 3 concave lens 4 convex lens 5 cover glass 6 upper and lower light shielding mask (first light shielding mask) 7 left and right light shielding mask (second light shielding mask) OL objective lens 14 image inverting means 15 field lens 16 field frame 20 video Camera body 21 Imaging optical system 22 Imaging means 23 Recording means 24 Viewfinder system 25 Display panel

Claims (11)

[Claims] 1. A viewfinder system comprising: a field frame for regulating a viewfinder field; and an eyepiece for guiding a light beam from a viewfinder image formed in or near the field frame to an eyeball of an observer. Has a negative lens and a positive lens that moves on the finder optical axis in order from the field frame side to adjust the finder diopter, and the first light blocking means that shields the peripheral lens in the short side direction of the finder light with the negative lens. A finder system, wherein the positive lens is provided with a second light-blocking means for blocking peripheral luminous fluxes in the long side direction of the finder luminous flux. 2. A field frame for regulating a viewfinder field, an image reversing means for converting a finder image formed at or near the field frame into an erect image, and a light beam from the image reversing means being guided to an eyeball of an observer. In a finder system having an eyepiece for the eyepiece, the eyepiece has a positive lens that moves on the optical axis of the finder and a negative lens in order from the field frame side to adjust the finder diopter. A finder system comprising: a first light blocking means for blocking peripheral light beams in the short side direction; and a second light blocking means for blocking the peripheral light beams in the long side direction of the finder light beam on the positive lens. 3. A finder system comprising: an objective lens for forming a finder image in or near the field frame for regulating a finder visual field; and an eyepiece for guiding a light beam from the finder image to an eyeball of an observer. The eyepiece has a negative lens and a positive lens that moves on the finder optical axis in order from the field frame side to adjust the finder diopter, and the first lens blocks the peripheral luminous flux in the short side direction of the finder luminous flux with the negative lens. A finder system comprising: a light shielding means; and a second light shielding means for shielding the peripheral light flux in the long side direction of the finder light flux on the positive lens. 4. The finder system according to claim 1, wherein said first light blocking means is provided on an incident surface side of said negative lens. 5. The apparatus according to claim 1, wherein said second light shielding means is provided on an exit surface side of said positive lens.
Or the finder system according to 3. 6. The light-shielding device according to claim 1, wherein the second light-shielding means shields a peripheral light beam in a range larger than a finder effective light beam and smaller than a lens effective range of the positive lens. Finder system. 7. The finder system according to claim 1, wherein said first and second light shielding means are made of a light shielding sheet material. 8. The finder system according to claim 7, wherein said light-shielding sheet material is adhered and fixed to said negative lens and said positive lens. 9. The method according to claim 1, wherein said first and second light-shielding means are made of a light-shielding paint.
Finder system of the term. 10. The finder device according to claim 9, wherein said light-shielding paint is applied and printed on said negative lens and said positive lens. 11. An optical apparatus comprising the finder system according to any one of claims 1 to 10.