JPH0815640A - Stereoscopic viewing mirror - Google Patents

Abstract

PURPOSE:To obtain bright videos having sufficient stereoscopic visual sensation and transparent feel by alternately laying many optical elements having two kinds of refraction functions offcentered to horizontal left and right directions, thereby forming a screen for projecting the exit rays from an objective lens. CONSTITUTION:The rays from the object 1 pass the objective lens 2 and mirrors 3 to 6 and are projected by erecting on the screen 7. The screen 7 is laid with many fine spherical lenses in a planar form to constitute an integrated lens. This integrated lens is alternately laid with two kinds of the spherical lenses respectively offcentered in the horizontal left direction and the horizontal right direction. Then, the ray fluxes projected to the screen 7 are branched and released to the horizontal left and right directions. Condenser lenses 8, 9 are installed before and behind the screen 7. The exit pupil of the objective lens 2 is formed as visual field pupils 10 in the conjugate positions outside the screen surface by the cooperative operation of both condenser lenses 8, 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for giving stereoscopic perception when an object is magnified and observed.

[0002]

2. Description of the Related Art When observing an object, it is perceived stereoscopically that the binocular parallax of the observer's eyes is the extent of the angle between the two lines of sight of the observer. This is because it acts psychologically. When observing an object using a magnifying glass made up of a single lens, the image can be observed and stereoscopically viewed because the two right and left light rays reaching both eyes of the observer see the exit pupil of the magnifying glass. This is because they can pass at the same time.

However, since a magnifying glass composed of a single lens generally has a low magnifying power, it cannot be applied to the desire to magnify and observe an object. On the other hand, in a device that employs a projection optical system, due to the optical principle, when the enlargement magnification is increased, the angle of the light beam projected from the objective lens is reduced by the extent to which the projection image is enlarged, and it is formed at the visual field position. The pupil of the visual field becomes smaller and its diameter is smaller than the pupil width of the observer, so that the observer cannot observe the image with both eyes. That is, it is not possible to stereoscopically observe a magnified image of an object by a method of projecting only by using an objective lens and a simple means.

For the purpose of reproducing this stereoscopic sensation with a projection optical system, devices having various optical or mechanical structures have been conventionally provided. An apparatus in which an objective lens is installed in a compound eye and each image is observed with both eyes, or an optical path using a compound eye objective lens or a monocular objective lens is used.
A device for observing images in two field pupils obtained by projecting on a screen surface of low diffusion magnification with both eyes using a means for branching into a bundle of rays, or high diffusion with many fine spherical lenses laid. There are devices and the like for observing an image projected by a monocular objective lens on a screen surface of magnification from within one extended field pupil.

However, in an apparatus for directly observing an image with a compound eye objective lens, the pupil of the exit from the objective lens is small, so that both eyes of the observer must be fixed at the position of the exit pupil (eye point). There are very limited difficulties in use. Further, when changing the projection magnification, there is a troublesome operation in which two objective lenses must be replaced or changed at the same time.

In an apparatus for projecting two light beam bundles on a transmissive screen surface having a low diffusion ratio, the two light field pupils formed by the light beam bundles emitted from the transmissive screen outside the screen surface are observed by an observer. It is possible to observe the image formed on the screen surface by transmitting and receiving with each of the two eyes, but in the assembly work of this device, the two images formed by the light flux are reflected on the screen surface. It requires a high degree of complicated adjustment skills that must be matched in the axial direction and the direction perpendicular to the optical axis.

In an apparatus of the type in which an image of an objective lens is formed on a reflective screen surface having a low diffusion magnification, there is a difficulty in adjustment work in which two images must be matched with each other, and a ray bundle is reflected. Therefore, since the screen surface must be installed with an inclination, an image distortion phenomenon occurs. In addition, since it is necessary to secure a long distance between the pupils of the visual field, there is a drawback that the image looks deep inside the observation device.

A device using a screen with a high diffusion factor is
It has a screen surface having a plate-like structure in which a large number of fine spherical lenses are laid. The screen divides the projected image received from the objective lens into fine pixels, and at the same time refracts and expands the divergence angle of the light beam bundle from the subdivided pixels, thereby expanding the field pupil outside the screen surface. There is a function to form. The observer can simultaneously place both eyes in the only magnified field pupil.
The light rays reaching the both eyes correspond to the light rays that the entrance pupil of the objective lens looks at the object, so that the observer can stereoscopically view the object. However, this device has a problem that the depth of field is reduced because the angular magnification of the screen is increased, and the pupil of the field of view is greatly enlarged, so that the illuminance of the field of view is reduced. To compensate for that, the object must be illuminated brightly. Therefore, a high-luminance illuminating device is required, and there is a concern that the heat rays of the illumination may cause deterioration of the quality of the object.

[0009]

SUMMARY OF THE INVENTION The present invention solves these difficulties in assembly work and use. Provided with a magnifying glass which is composed of simple parts and which does not require any adjustment work between the parts and can observe a clear image of a bright subject having sufficient stereoscopic perception and transparency. Is.

That is, the first object of the present invention is to obtain sufficient stereoscopic perception. Next, the second purpose is to ensure that the observation field of view is bright. A third object is to obtain an image by forming an image on a place where it is easy to observe. The fourth purpose is to change only one objective lens when changing the projection magnification, and to zoom the only objective lens in order to simplify the magnification conversion procedure. It is to provide a configuration that can be replaced with a lens. Further, the fifth purpose is an extremely simple structure, which is constructed by the minimum necessary members,
The parts have a simple structure, to obtain a device that does not require any special adjustment skills during the assembly of the parts and during use.

[0011]

When a bundle of rays emitted from a single objective lens is formed on a screen surface and then branched into two horizontal and horizontal directions to form two field pupils, the images are equivalent. However, if the distance between the pupils of the visual field (eye width) is slightly smaller than the pupil distance of the observer when both eyes of the observer exchange, the images in a single visual field pupil are observed from the left and right. The present invention focuses on the property that it is equivalent to the above-mentioned thing, and therefore can stereoscopically view an object.

In order to achieve this object, according to the present invention, a light beam from an objective lens is transmitted and received by a transmissive screen or a reflective screen in which a large number of fine optical elements having a refraction function are integrated in a plate shape, and a light beam bundle thereof. Is divided into fine pixels, and at the same time, it is branched in the horizontal and horizontal directions and emitted from the screen, and has the function of forming two field pupils outside the screen. Pixels subdivided on the screen surface are macroscopically observed as a single image. The two pupils of the visual field are transmitted and received by both eyes of the observer, which is equivalent to a state in which the object is viewed from the left and right, and the observer can perceive the object as a stereoscopic object.

[0013]

According to the present invention, the light flux imaged on the screen is
The light rays from the objective lens are formed in the same two field pupils outside the screen by utilizing the effect of splitting by the decentered fine refracting optical element which constitutes the screen and branching into two left and right directions.

The optical action will be described along the optical axis with the configuration example shown in FIG. The light beam from the object 1 passes through the objective lens 2, is reflected by the mirrors 3, 4 and 5 and 6 to erect the image, and is projected on the screen 7.

The screen 7 has a large number of fine spherical lenses laid in a plate shape to form an integrated lens. In this integrated lens, two types of spherical lenses, one decentered in the horizontal left direction and one decentered in the horizontal right direction, are alternately laid. A lens in which the optical axis of the lens is decentered from the original optical axis has the function of deviating the incident light beam to the left or right and emitting it. Therefore, the ray bundle projected on the screen 7 is branched and emitted in the horizontal left and right directions.

Since a fine spherical lens has a refractive power, it has an angular magnification, and an incident light beam is diffused and emitted from the screen 7.

Condensing lenses 8 and 9 are installed in front of and behind the screen 7. The condenser lens 8 is the objective lens 2
The light rays from are converted into a direction substantially perpendicular to the screen 7, and the condenser lens 9 functions to deflect the light rays emitted from the screen 7 in the direction of the position of the observing eye. With the cooperation of both condenser lenses 8 and 9, the exit pupil of the objective lens 2 is brought to a conjugate position outside the screen surface and the field pupil 10 is provided.
To form as.

By the integrated function of the screen 7 and the condenser lenses 8 and 9, the exit pupil of the objective lens 2 is mapped to the position of the exit pupil distance having a conjugate relationship, and two left and right field pupils 10 are formed.

By appropriately setting the amount of eccentricity in the horizontal and horizontal directions of the fine lens, the interval (eye width) between the two field pupils 10 can be set to be slightly smaller than the observer's pupil distance e. When set in this way, both eyes of an observer having a pupil distance e slightly wider than the pupil distance of the field pupil 10 can be viewed from within the field pupil 10 having two equivalent images formed on the screen surface. Thus, the object 1 producing the image is equivalent to the entrance pupil of the objective lens looking from the left and right.

FIG. 2 shows the expanded optical path. The aperture angle α of the objective lens 2 which desires the object 1 becomes the approach angle β when the image is enlarged and projected on the screen 7, and is converted into the emission angle γ by the refracting power of the fine lens of the screen 7. Focal length f _L and exit pupil size D, that is, aperture ratio _FL
With the objective lens 2 of, the approach angle β is changed according to the projection magnification m.
Is β = D / 2 (m + 1) f _L = 1/2 (m + 1) F _L , and the aperture ratio F _s of the fine spherical lens of the screen 7 is
Thus, the emission angle γ is γ = β + (1 / 2F _s ) = [1/2 (m + 1) F _L ] +
(1/2 F _s ).

Assuming that the focal length of each of the fine spherical lenses constituting the screen 7 is f _s and the amount of decentering is ε, the deviation angle δ at which the optical axis of the light beam incident on this spherical lens changes direction.
Is δ = ε / _{f s.}

Therefore, one of the light beam bundles branched from the screen 7 is emitted while being spread between the angle δ-γ and the angle δ + γ. The exit pupil of the objective lens 2 moves from the screen 7 to the clear viewing distance l by the action of the condenser lenses 8 and 9.
Since it is formed as a field pupil 10 on the
Is φ = 2lγ = l {[1 / (m + 1) F _L ] + (1 /
F _s )}

On the other hand, the viewing angle at which the both eyes 11 having the observer's pupil distance e look at the scoop 7 at the clear viewing distance l is e /
It is l. Therefore, the range in which both eyes 11 can enter the visual field pupil 10 and observe the image is δ = γ ≦ e / l ≦ δ + γ
The condition for stereoscopic viewing within that range is δ <e
/ L ≦ γ + δ. In order to view the image without confusion, the left and right field pupils 10
.. must not intersect, so .delta .-. Gamma.> 0. Summing up the above, the condition of γ <δ <e / l ≦ γ + δ is required.

[0024]

EXAMPLE The fine lens group constituting the screen 7 is preferably composed of a diverging optical system in order to maintain the posture of the image. When using a concave lens, it is preferable because only one lens is required, but when applying a convex lens, two lenses are stacked and installed. In the screen 7 composed of only the convex lens or the concave lens, the image is transferred from the real image to the virtual image or vice versa depending on the distance relationship between the fine lens and the image forming position, so that the depth of field is somewhat limited. .

FIG. 3 shows a screen 7 composed of an integrated plate in which a large number of optical element units in which convex lenses and concave lenses are laminated are laid, and which is formed by a beam splitting means with an afocal optical system. . Afford optics
It is a combination in which the image focus of the front lens and the object focus of the rear lens that are configured are shared, and the characteristic is that the angular magnification is the ratio of the focal lengths of both lenses and is always constant. The image formation is always a virtual image and is stable, and therefore has a feature that the depth of field is deep.

The means for splitting an incident light beam with an afocal optical system is a structural unit in which one concave lens is combined with two convex lenses, or two concave lenses are combined with one convex lens, as shown in FIG. And

By setting the distance between the lens integrated plates before and after the afocal optical system to be freely adjustable, the characteristic of the optical system of the screen 7 can be arbitrarily changed.

Although the fine lenses constituting the screen have been described above as spherical lenses, the same is true even if fine cylindrical lenses are formed on an integrated plate (lenticular lens) laid in parallel to facilitate processing and production. Exhibits optical characteristics. In this case, concentric cylindrical lenses are laid in parallel in the horizontal direction of the screen 7, and cylindrical lenses eccentric to the left and right are laid in the vertical direction.

Although the above description has been made in the case of application to the transmissive screen, the same optical characteristics are exhibited even when applied to the reflective screen. The reflection type screen is one in which fine lenses that are decentered alternately in the horizontal and left and right directions are provided on the front surface and a flat reflecting mirror is provided on the back surface, or reflections in which fine reflection elements that are alternately inclined in the horizontal and horizontal directions are laid on the surface. Composed of a mirror.

[0030]

Since the present invention is configured as described above, it has the following effects.

The field pupil is of a size necessary for observation,
Since the light flux diverging from the screen 7 does not spread to a range not necessary for observation, the illuminance of the visual field does not decrease and a bright image can be observed.

Since there is only one projection optical path from the objective lens 2, it is easy to focus on the screen 7, there is no fear of double image formation, and an image of good quality can be secured.

According to the present invention, the image space of the objective lens 1 is different from that of the stereoscopic system in which a large number of optical elements must be incorporated in order to guide the light beam from the objective lens by dividing it into two optical paths. There is no complicated optical element due to the single light flux, and the installation location and size of the screen 7 can be designed relatively freely.

Although the screen 7 has a simple structure,
The stereoscopic view of the subject can be strongly perceived.

Since there is only one objective lens 2, the conversion of the projection magnification is very easy, and it is possible to replace that lens with a zoom lens.

Since there is only one projection optical path from the objective lens 2, the construction of the optical elements from the objective lens 2 to the screen 7 is simple, so that the projection optical path can be set short, and therefore the entire apparatus is designed to be compact. It is possible.

[0037]

[Brief description of drawings]

FIG. 1 is a perspective view of an optical path in which an optical element is arranged in a projection optical system of the present invention.

FIG. 2 is an explanatory diagram developed along the optical axis to show the optical action of the configuration of the present invention.

FIG. 3 is a structural diagram showing an example in which a large number of optical element units laid on a screen to form an integrated plate are formed by combining a convex lens and a concave lens.

[Explanation of symbols]

1 Subject 2 Objective Lenses 3, 4, 5 and 6 Optical Member Combining Reflective Optical Elements 7 Screens 8 and 9 Condensing Lens 10 Field Hitomi 11 Both Eyes of Observer

Claims (4)

[Claims] 1. A screen on which a light beam emitted from an objective lens is projected is formed by alternately laying a plurality of optical elements having two kinds of refracting functions, which are eccentric in a horizontal left direction and a horizontal right direction, to form an integrated plate. A stereoscope that is characterized by 2. A stereoscopic endoscope characterized in that the screen is constructed by laying a large number of fine spherical refraction functional elements which are eccentric in the horizontal left direction and the horizontal right direction. 3. A stereoscopic endoscope characterized in that a screen is constructed by laying a large number of fine cylindrical refracting functional elements which are eccentric in a horizontal left direction and a horizontal right direction. 4. A screen is formed by forming an optical system in which one coaxial refractive functional optical element and two decentered refractive functional optical elements are combined as a unit, and integrating these units in a large number. A stereoscopic endoscope characterized by being used.