JP2008096552A - Observing optical system, lens barrel unit, and camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an observing optical system that has a sufficient viewing angle but is small in effective diameter and short in its over all length, and can fully stand the practical use as an observing optical system with less optical elements, and provide its lens barrel unit and camera. <P>SOLUTION: This observing optical system has an eyepiece optical system 2 of an overall positive refractive power, and a display 3 near the focal plane of the eyepiece optical system 2 both sequentially arranged in this order from the pupil 1 side to the object in order to observe the various information magnified on the display 3. When representing the area of the display 3 by S<SB>1</SB>and the focusing distance of the eyepiece optical system by fe<SB>1</SB>, it satisfies condition (1) 0.015<S<SB>1</SB>/fe<SB>1</SB><SP>2</SP><0.30. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to observation optics such as so-called EVF (Electronic View Finder) for magnifying and observing a display device such as a liquid crystal display panel for displaying an image photographed by a photographing optical system or a reproduced image in a digital camera or a digital video camera. The present invention relates to a system, a lens barrel unit including the observation optical system, and a camera including the lens barrel unit.

  Recent cameras, particularly digital cameras, can be broadly classified into a type in which the casing is thin with respect to portability and a type in which the zoom ratio of the zooming optical system is more important than the size of the casing. In the former, thinning has progressed to the point where it is physically difficult to mount an optical observation optical system typified by a real image finder. In the latter, the parallax on the telephoto side is large, and the adoption of the optical observation optical system is difficult in terms of function.

  Under such circumstances, an increasing number of cameras adopt an observation optical system called EVF or the like that magnifies and observes an image displayed on a display member such as a small liquid crystal display panel instead of an optical observation optical system. As an example of EVF, a liquid crystal view finder for observing a finder image by a liquid crystal display plate through an eyepiece is known. As a conventional example of a liquid crystal viewfinder, the eyepiece is supported so as to be movable in the optical axis direction for diopter adjustment, and when the parallel light is incident on the liquid crystal viewfinder from the observation side, the eyepiece is within the movable range. The incident light is condensed on the opposite side of the eyepiece from the surface closest to the eyepiece of the liquid crystal element sealing glass of the liquid crystal display panel, and any position in the movable range is Thus, there is a configuration in which the incident light is condensed on a liquid crystal surface of a liquid crystal display panel (see, for example, Patent Document 1).

  According to the invention described in Patent Document 1, by setting the imaging surface of the back-incident light entering the liquid crystal viewfinder by the eyepiece lens inside the sealing glass surface, the polarizing plate, the mask plate, the structural member, etc. Even if it arrange | positions, the thermal damage by the back incident light of these members can be prevented.

Japanese Patent No. 3493554

The conventional EVF found in the liquid crystal viewfinder is desired to further improve the observation optical system in order to meet the demands for miniaturization and thinning of the camera. That is, it is desirable that the effective diameter is small, the total length is short, and the optical system can be sufficiently put into practical use as an observation optical system with a small number of optical elements while having a sufficiently large viewing angle.
The invention described in Patent Document 1 is an invention that focuses on a solution problem different from such a solution problem, and cannot meet the above-described requirements.

The present invention has been made to satisfy the above improvement requirements, and has a sufficient viewing angle, a small effective diameter, a short overall length, a small size, and a sufficient number of optical elements as an observation optical system. An object of the present invention is to provide an observation optical system that can withstand practical use.
Another object of the present invention is to provide a lens barrel unit using an observation optical system that satisfies the above improvement requirements and a camera using the same.

The invention according to claim 1 of the present application includes an eyepiece optical system having a positive refractive power as a whole in order from the pupil side to the object side, and a display member disposed in the vicinity of the focal plane of the eyepiece optical system. In the observation optical system for magnifying and observing various information displayed on the display member, when the area of the information display surface of the display member is S ₁ and the combined focal length of the eyepiece optical system is fe ₁ ,
0.015 <S ₁ / fe ₁ ² <0.30 (1)
It satisfies the following conditions.

The invention according to claim 2 of the present application includes, in order from the pupil side to the object side, an eyepiece optical system having a positive refractive power as a whole, a reflecting member that bends the optical axis of the eyepiece optical system, and the eyepiece optical system and the reflecting member. In an observation optical system having a display member arranged in the vicinity of the synthetic focal plane and magnifying and observing various information displayed on the display member, the area of the information display surface of the display member is S ₁ , and the eyepiece optical system and the reflection member When the combined focal length is fe ₂ ,
0.015 <S ₁ / fe ₂ ² <0.30 (2)
It satisfies the following conditions.

The invention according to claim 3 of the present application has, in order from the pupil side to the object side, an eyepiece optical system having a positive refractive power as a whole, a reflecting member for bending the optical axis of the eyepiece optical system, and a positive or negative refractive power. In an observation optical system having an optical element and a display member disposed in the vicinity of the synthetic focal plane of the eyepiece optical system, the reflecting member, and the optical element, and magnifying and observing various information displayed on the display member
When the area of the information display surface of the display member is S ₁ and the combined focal length of the eyepiece optical system, the reflection member, and the optical element is fe ₃ ,
0.015 <S ₁ / fe ₃ ² <0.30 (3)
It satisfies the following conditions.

  The invention according to claim 4 of the present application is characterized in that, in the observation optical system according to any one of claims 1 to 3, the observation optical system has a diopter adjustment function.

  The invention according to claim 5 of the present application is characterized in that, in the observation optical system according to any one of claims 1 to 4, the observation optical system has a zooming function.

  The invention according to claim 6 of the present application is the observation optical system according to any one of claims 1 to 5, wherein the display member is a display device using a liquid crystal display panel.

  According to a seventh aspect of the present invention, in the observation optical system according to the sixth aspect, the display device displays a captured image or a reproduced image of a digital still camera or a digital video camera.

  The invention according to claim 8 of the present application is an invention according to the lens barrel unit, characterized in that the observation optical system according to any one of claims 1 to 7 and the photographing optical system are combined. .

  According to a ninth aspect of the present invention, in the lens barrel unit according to the eighth aspect, the observation optical system and the photographing optical system are coupled so as to be relatively movable, and the light of the observation optical system with respect to the optical axis of the photographing optical system. It is characterized in that the axes can be crossed.

  The invention according to claim 10 of the present application relates to a camera using the lens barrel unit described in claim 8 or 9.

According to the first aspect of the present invention, the eyepiece optical system having a positive refractive power as a whole and the display member disposed in the vicinity of the focal plane of the eyepiece optical system in order from the pupil side to the object side are provided. In the observation optical system for magnifying and observing various information displayed on the display member, when the area of the information display surface of the display member is S ₁ and the combined focal length of the eyepiece optical system is fe ₁ ,
0.015 <S ₁ / fe ₁ ² <0.30 (1)
By satisfying the above condition, it is possible to obtain an observation optical system that has a sufficient viewing angle, a small effective diameter, a short overall length, a small size, and can sufficiently withstand practical use with a small number of optical elements.
If the lower limit of the expression (1) is exceeded, the image magnification becomes small and the details of the image become indistinguishable in both cases where S ₁ is too small and fe ₁ ² is too large, and the practicality as an observation optical system becomes poor. More specifically, it is difficult to determine whether the subject is in focus or to read information such as the shutter speed and the shooting mode displayed in the field of view.
One of the objects of the present invention is to provide a small observation optical system when the upper limit of the expression (1) is exceeded, regardless of whether S ₁ is excessively large or fe ₁ ² is excessively small. It will be difficult to achieve. Needless to say, it is difficult to reduce the size of the observation optical system when S ₁ is excessively large. However, when fe ₁ ² is excessively small, the photographing optical system has a wide viewing angle. Increasing the number of optical elements directly increases the cost of the eyepiece optical system. In addition, if it is attempted to correct aberrations with a small number of optical elements by giving priority to size, design becomes difficult.

According to the second aspect of the present invention, the eyepiece optical system having a positive refractive power as a whole in order from the pupil side to the object side, the reflecting member that bends the optical axis of the eyepiece optical system, and the eyepiece optical system and the reflecting member. In an observation optical system having a display member arranged in the vicinity of the synthetic focal plane and magnifying and observing various information displayed on the display member, the area of the information display surface of the display member is S ₁ , and the eyepiece optical system and the reflection member When the combined focal length is fe ₂ ,
0.015 <S ₁ / fe ₂ ² <0.30 (2)
By satisfying the above condition, it is possible to obtain an observation optical system that has a sufficient viewing angle, a small effective diameter, a short overall length, a small size, and can sufficiently withstand practical use with a small number of optical elements.
(2) exceeds the lower limit of the formula, S ₁ is excessively small, the image magnification may fe ₂ ² is either excessively decreases, utility as an observation optical system details of the image becomes indistinguishable becomes poor. More specifically, it is difficult to determine whether the subject is in focus or to read information such as the shutter speed and the shooting mode displayed in the field of view.
(2) exceeds the upper limit of the expression, one of the objects of the present invention that S ₁ is excessive, fe ₂ ² increases the size of even the observation optical system in any case of too small, to provide a compact viewing optical system It will be difficult to achieve. Although it is needless to say that S ₁ is the miniaturization of the observation optical system in the case of excessive becomes difficult, because if fe ₂ ² is too small is that the imaging optical system becomes wide viewing angle, with the performance priority Increasing the number of optical elements directly increases the cost of the eyepiece optical system. In addition, if it is attempted to correct aberrations with a small number of optical elements by giving priority to size, design becomes difficult.

According to the third aspect of the present invention, an eyepiece optical system having a positive refractive power as a whole, a reflecting member that bends the optical axis of the eyepiece optical system, and an optical element having a positive or negative refractive power in order from the pupil side to the object side. An information display surface of a display member in an observation optical system having an element and a display member disposed in the vicinity of a synthetic focal plane of the eyepiece optical system, the reflection member, and the optical element, and magnifying and observing various information displayed on the display member Is S ₁ , and the combined focal length of the eyepiece optical system, the reflecting member, and the optical element is fe ₃ ,
0.015 <S ₁ / fe ₃ ² <0.30 (3)
By satisfying the above condition, it is possible to obtain an observation optical system that has a sufficient viewing angle, a small effective diameter, a short overall length, a small size, and can sufficiently withstand practical use with a small number of optical elements.
If the lower limit of the expression (3) is exceeded, the image magnification will be small in both cases where S ₁ is too small and fe ₃ ² is too large, making the image details indistinguishable, making the practicality of the observation optical system poor. More specifically, it is difficult to determine whether the subject is in focus or to read information such as the shutter speed and the shooting mode displayed in the field of view.
If the upper limit of the expression (3) is exceeded, one of the objects of the present invention is to provide a small observation optical system by increasing the size of the observation optical system when S ₁ is excessively large and fe ₃ ² is excessively small. It will be difficult to achieve. Needless to say, it is difficult to reduce the size of the observation optical system when S ₁ is excessively large. However, when fe ₃ ² is excessively small, the photographing optical system has a wide viewing angle. Increasing the number of optical elements directly increases the cost of the eyepiece optical system. In addition, if it is attempted to correct aberrations with a small number of optical elements by giving priority to size, design becomes difficult.

  The invention according to claim 4 is characterized in that the observation optical system according to any one of claims 1 to 3 has a diopter adjustment mechanism, so that it can be adapted to the visual acuity that changes depending on the physical condition and time zone of the photographer. Thus, it is possible to adjust the diopter, and it is possible to always obtain a good observation image with a suitable diopter. In addition, even when a plurality of users share, it is possible to obtain a favorable observation image by adjusting the diopter according to the visual acuity of each user.

  The invention according to claim 5 is characterized in that the observation optical system according to any one of claims 1 to 4 has a zooming function, so that an image magnification suitable for the purpose of use can be obtained. . Specifically, it is possible to selectively use such as increasing the image magnification to make it easy to confirm details of the observation image, or decreasing the image magnification to make it easy to recognize changes in the surrounding observation image.

  In the invention described in claim 6, the display member of the observation optical system according to any one of claims 1 to 5 is a display device using a liquid crystal display panel. It is possible to display an observation image using an electrical signal.

  In the invention described in claim 7, since the liquid crystal display device of the observation optical system described in claim 6 is a display device for a photographed image or a reproduced image in a digital still camera or digital video camera, the digital still camera or digital video camera It is suitable as an observation optical system.

  In the invention described in claim 8, since the lens barrel unit is coupled to the observation optical system described in claims 1 to 7, the effective diameter is small, the overall length is short, and the size is small while having a sufficient viewing angle. An observation optical system that can sufficiently withstand practical use can be obtained with a small number of optical elements.

  In a ninth aspect of the present invention, the lens barrel unit according to the eighth aspect is configured such that the observation optical system and the photographing optical system are coupled so as to be relatively movable, and the optical axis of the observation optical system is set to the optical axis of the photographing optical system. Since it is configured to be able to cross each other, the degree of freedom of the visual axis and posture of the user looking through the observation optical system is increased, and it is possible to reduce the shooting angle and reduce fatigue due to shooting.

  In the invention according to claim 10, since the lens barrel unit according to claim 8 or 9 is used for a camera such as a digital still camera or a digital video camera, the effective diameter is small and the total length is small while having a sufficient viewing angle. It is possible to obtain a camera that is short, small, and can sufficiently withstand practical use with a small number of optical elements. Further, by using the observation optical system according to the present invention, a small lens barrel unit can be obtained, and thus a camera such as a small digital still camera or digital video camera can be obtained.

  Hereinafter, embodiments of an observation optical system, a lens barrel unit, and a camera according to the present invention will be described with reference to the drawings.

1 and 2 show two embodiments according to Example 1 of the observation optical system according to the present invention. The embodiment shown in FIG. 1 includes an eyepiece optical system 2 having positive refractive power and a display member 3 disposed in the vicinity of the focal plane of the eyepiece optical system 2 in order from the pupil 1 side to the object side. The eyepiece optical system 2 is for magnifying and observing various types of information displayed on the display member 3, and in this embodiment is constituted by a biconvex single lens. The embodiment shown in FIG. 2 uses two lenses 201 and 202 having positive refractive power in the eyepiece optical system 2. In the embodiment shown in FIG. 2, since the refractive power of the eyepiece optical system 2 is dispersed in the two lenses 201 and 202, it is generally easier to correct the aberration than in the embodiment shown in FIG. . When the area of the information display surface of the display member 3 is S ₁ and the combined focal length of the eyepiece optical system is fe ₁ , the conditional expression (1) is satisfied.

3 and 4 show two embodiments according to Example 2 of the observation optical system according to the present invention. In the embodiment shown in FIG. 3, the eyepiece optical system 2 is composed of two convex lenses 211 and 212, and the reflecting member 4 is arranged on the display member 3 side of the eyepiece optical system 2. Therefore, in order from the pupil side 1 toward the object side, the eyepiece optical system 2 having a positive refractive power as a whole, the reflection member 4, and the display member 3 disposed in the vicinity of the combined focal plane of the eyepiece optical system 2 and the reflection member 4 are arranged. Have.
In the embodiment shown in FIG. 4, the eyepiece optical system 2 includes three lenses, a lens 221 having a negative refractive power, a lens 222 having a positive refractive power, and a lens 212 having a positive refractive power in order from the object side. It has a positive refractive power as a whole. A reflecting member 4 is disposed between the eyepiece optical system 2 and the display member 3. The display member 3 is disposed in the vicinity of the focal plane of the eyepiece optical system 2.

In the embodiment shown in FIGS. 3 and 4, when the area of the information display surface of the display member 3 is S ₁ and the combined focal length of the eyepiece optical system 2 and the reflection member 4 is fe ₂ , the conditional expression (2) above. It is configured to satisfy.
Although the optical path is bent due to the presence of the reflecting member 4, in FIGS. 3 and 4, the optical path is drawn in a state where the optical path is not bent for simplification. The actual optical path is bent approximately 90 degrees by the reflecting member 4, and the display surface of the display member 3 is arranged in a direction substantially parallel to the optical axis passing through the pupil 1. With such an arrangement, it is possible to further reduce the dimension in the depth direction along the optical axis of the observation optical system 2.

5 and 6 show two embodiments according to Example 3 of the observation optical system according to the present invention. The embodiment shown in FIG. 5 includes a first eyepiece optical system 2 having a positive refractive power as a whole, a reflecting member 4, and a second eyepiece optical system having a negative refractive power in order from the pupil side 1 to the object side. 5 and the display member 3 disposed in the vicinity of the combined focal plane of the first and second eyepiece optical systems 2 and 5 and the reflecting member 4. In other words, the reflecting member 4 is disposed between the first eyepiece optical system 2 and the second eyepiece optical system 5. The first eyepiece optical system 2 includes two convex lenses 231 and 232, and the first eyepiece optical system 2 and the first and second eyepiece optical systems 2 and 5 as a whole have a positive refractive power.
The embodiment shown in FIG. 6 includes a first ocular optical system 2 having a single refractive power on the pupil 1 side and a second two-group three-lens structure having a positive refractive power on the display member 3 side. The reflecting member 4 is disposed between the eyepiece optical system 5 and the eyepiece optical system 5. The second eyepiece optical system 5 includes a lens 501 having a negative refractive power, a cemented biconvex lens 502, and a negative meniscus lens 503 in order from the object side, and has a positive refractive power as a whole.

5 and 6, when the area of the information display surface of the display member 3 is S ₁ , and the combined focal length of the eyepiece optical systems 2, 5, the reflection member 4, and the optical element is fe ₃ , It is configured to satisfy the conditional expression (3). The “optical element” refers to the second eyepiece optical system 5 in this embodiment.
According to Example 3 shown in FIGS. 5 and 6, since the reflecting member 4 is disposed inside the eyepiece optical system, the total length in the depth direction along the optical axis is further reduced as compared with the configuration of Example 2. It becomes possible to do.

  The reflecting member 4 may be configured by a mirror as in the examples shown in FIGS. 3, 4, and 5, or may be a reflecting member using a prism whose concept is shown in FIG. In the case of using a prism, it is possible to distribute the refractive power to each surface of the prism so as to be a part of the eyepiece optical system.

  A diopter adjustment mechanism may be added to the observation optical system according to the present invention. FIG. 7 shows the concept of the diopter adjustment function. In FIG. 7, an eyepiece optical system 2 having a positive refractive power as a whole and a display member 3 disposed in the vicinity of the focal plane of the eyepiece optical system 2 are arranged in order from the pupil 1 side to the object side. Various types of information displayed on the display member 3 can be enlarged and observed through the eyepiece optical system 2. The eyepiece optical system 2 includes two convex lenses 241 and 242. The eyepiece optical system 2 is movable along the optical axis. By moving the eyepiece optical system 2 in the direction of the optical axis, the diopter of the virtual image of the display member 3 to be observed by the observer is changed and observed. It can be adjusted to an easy diopter. In the example shown in FIG. 4, the entire eyepiece optical system 2 having two elements in two groups is moved. However, the diopter is adjusted by moving only some of the optical elements constituting the eyepiece optical system 2. It is also possible to adjust. For example, in the example shown in FIG. 4, diopter adjustment is possible by moving only the optical element (lens 242) on the pupil 1 side, or moving only the first eyepiece optical system 2 in the embodiment shown in FIG. . In particular, as in the examples shown in FIGS. 5 and 6, in the case of a configuration in which the eyepiece optical system is separated with the reflecting member 4 interposed therebetween, either one of the eyepiece optical systems is moved in consideration of the complexity of the moving mechanism. It is desirable to configure so that the diopter is adjusted. Also in this embodiment, it is assumed that the conditional expressions (1), (2), and (3) are satisfied.

  In the embodiment shown in FIG. 8, the eyepiece optical system 2 is divided into the first group 21 and the second group 22 from the pupil 1 side, and the focal length is changed by changing the distance between the groups 21 and 22, so that the image magnification is increased. Is to change. The principle of zooming is the same as that of a general zooming optical system, and the focal length is continuously changed without changing the focal plane of the eyepiece optical system 2 from the vicinity of the display member 3. The positions of the first group 21 and the second group 22 of the eyepiece optical system 2 at the wide-angle end in the upper part of FIG. 8, the positions of the first group 21 and the second group 22 at the intermediate magnification in the middle part, The positions of the first group 21 and the second group 22 at the telephoto end are shown respectively. Also in this embodiment, it is assumed that the conditional expressions (1), (2), and (3) are satisfied.

  According to the embodiment shown in FIG. 8, an image magnification suitable for the purpose of use can be obtained. Specifically, it is possible to make it easier to confirm the details of the observation image by increasing the image magnification. Alternatively, it is possible to selectively use such that the image magnification is lowered to make it easier to recognize changes in the surrounding observation image.

  The display member 3 can be a display member 3 using a liquid crystal display panel as in the embodiment shown in FIG. In the embodiment shown in FIG. 9, a subject image is formed on an image sensor 8 such as a CCD by the photographic optical system 7, and a photographic image signal photoelectrically converted by the image sensor 8 is input to the display member 3. A subject image is displayed. The subject image displayed on the display member 3 can be observed through the observation optical system 2. In this way, the subject image is displayed on the display element 3 in real time, and this can be observed to function as a viewfinder. It is also possible to store the captured image in a memory, display the reproduced image on the display member 3, and observe this via the observation optical system 2. As described above, various images / videos can be displayed on the display member 3 through the display member driving device not shown in FIG. 9, and can be enlarged and observed through the observation optical system 2.

  In addition, as shown in FIG. 9, by displaying a photographed image or video of a digital still camera or digital video camera on a display device using a liquid crystal display panel, the finder determines a photographing range, or after photographing and recording. It can be used as a playback device by displaying images and videos.

  FIG. 10 shows an embodiment of a lens barrel unit provided with an observation optical system according to the present invention. In FIG. 10, a photographing optical system 71 is attached to the front side of the lens barrel unit main body 15. An observation optical system unit 10 is integrally attached to the upper end portion of the lens barrel unit main body 15 to form a lens barrel unit. By integrating the photographic optical system 71 and the observation optical system unit 10, the convenience of assembly and adjustment at the time of manufacture can be improved and the size can be reduced. By incorporating this lens barrel unit into the camera, the camera assembly and adjustment can be simplified, and the camera can be miniaturized.

  In the lens barrel unit in which the photographing optical system 71 and the observation optical system unit 10 are integrated as in the above-described embodiment, the observation optical system 10 and the photographing optical system 71 are relative to each other as in the embodiments shown in FIGS. It is good to combine so that movement is possible. As shown in FIG. 11, the optical axis of the photographing optical system 71 and the optical axis of the observation optical system 10 are usually parallel, but as shown in FIG. The observation optical system 10 is configured to be relatively movable so that the ten optical axes intersect. With this configuration, there is an effect that a variety of shooting angles are born. In addition, since the posture of the observer at the time of shooting is not limited, there is an effect that it is possible to shoot easily for a long time. It is desirable that the angle θ formed by the optical axis of the photographing optical system 71 and the optical axis of the observation optical system 10 shown in FIG. 12 can be moved from 0 degrees in the normal state to around 90 degrees.

  FIG. 13 shows an embodiment of a digital still camera using the lens barrel unit according to the present invention. In FIG. 13, the camera body 30 incorporates the lens barrel unit shown in FIGS. The photographic optical system 71 of the lens barrel unit corresponds to a photographic lens, and is arranged so as to be positioned on the front side of the camera body 30. The type of the photographing optical system 71 is not particularly limited, and may be a fixed focus type, a zoom lens, a retractable type, or the front surface of the camera body 30 at all times. You may protrude from. The observation optical system 10 protrudes from the upper end of the camera body 30 toward the upper rear so that the display member in the lens barrel unit can be observed through the eyepiece optical system 32 at the rear end of the observation optical system 10. It is configured. The camera body 30 is provided with a power switch button 34, a shutter button 36, a mode switching dial 38, and other operation members and display members for functioning as a camera and operating in various operation modes. The camera using the lens barrel unit according to the present invention is not limited to a digital still camera but may be a digital video camera, and the type and form of the camera are not limited.

It is an optical arrangement | positioning figure which shows one embodiment of the 1st Example of the observation optical system concerning this invention. It is an optical arrangement | positioning figure which shows another embodiment of the 1st Example of the observation optical system concerning this invention. It is an optical arrangement | positioning figure which shows one embodiment of the 2nd Example of the observation optical system concerning this invention. It is an optical arrangement | positioning figure which shows another embodiment of the 2nd Example of the observation optical system concerning this invention. It is an optical arrangement | positioning figure which shows one embodiment of the 3rd Example of the observation optical system concerning this invention. It is an optical arrangement | positioning figure which shows another embodiment of the 3rd Example of the observation optical system concerning this invention. It is an optical arrangement | positioning figure which shows the 4th Example of the observation optical system concerning this invention. It is an optical arrangement | positioning figure which shows 5th Example of the observation optical system concerning this invention. It is an optical arrangement | positioning figure which shows the 6th Example of the observation optical system concerning this invention. The Example of the lens barrel unit concerning this invention is shown, (a) is a top view, (b) is a front view, (c) is a right immediate view. It is a side view which shows the other Example of the lens barrel unit concerning this invention. It is a side view which shows the operation | movement aspect of the lens barrel unit concerning the said Example. It is an external appearance perspective view which shows the Example of the camera concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pupil 2 Eyepiece optical system 3 Display element 4 Reflecting member 5 Second eyepiece optical system 7 Imaging optical system 8 Image sensor

Claims (10)

An eyepiece optical system having a positive refractive power as a whole and a display member disposed near the focal plane of the eyepiece optical system in order from the pupil side to the object side, and various types of information displayed on the display member are enlarged and observed. In the observation optical system,
When the area of the information display surface of the display member is S ₁ and the combined focal length of the eyepiece optical system is fe ₁ ,
0.015 <S ₁ / fe ₁ ² <0.30 (1)
An observation optical system characterized by satisfying the following condition. In order from the pupil side to the object side, an eyepiece optical system having a positive refractive power as a whole, a reflecting member that bends the optical axis of the eyepiece optical system, and a display member that is disposed in the vicinity of the combined focal plane of the eyepiece optical system and the reflecting member In an observation optical system for magnifying and observing various information displayed on the display member,
When the area of the information display surface of the display member is S ₁ and the combined focal length of the eyepiece optical system and the reflection member is fe ₂ ,
0.015 <S ₁ / fe ₂ ² <0.30 (2)
An observation optical system characterized by satisfying the following condition. In order from the pupil side to the object side, an eyepiece optical system having a positive refractive power as a whole, a reflecting member for bending the optical axis of the eyepiece optical system, an optical element having a positive or negative refractive power, and the eyepiece optical system and the reflecting member And an observation optical system for magnifying and observing various types of information displayed on the display member.
When the area of the information display surface of the display member is S ₁ and the combined focal length of the eyepiece optical system, the reflection member, and the optical element is fe ₃ ,
0.015 <S ₁ / fe ₃ ² <0.30 (3)
An observation optical system characterized by satisfying the following condition.   The observation optical system according to any one of claims 1 to 3, wherein the observation optical system has a diopter adjustment function.   The observation optical system according to any one of claims 1 to 4, wherein the observation optical system has a zooming function.   6. The observation optical system according to claim 1, wherein the display member is a display device using a liquid crystal display panel.   The observation optical system according to claim 6, wherein the display device displays a captured image or a reproduced image of a digital still camera or a digital video camera.   8. A lens barrel unit, wherein the observation optical system according to claim 1 and a photographing optical system are combined.   9. The lens barrel unit according to claim 8, wherein the observation optical system and the photographing optical system are coupled so as to be relatively movable, and the optical axis of the observation optical system can intersect the optical axis of the photographing optical system.   A camera using the lens barrel unit according to claim 8.

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