JPH08334829A - Optical system for camera - Google Patents

Abstract

PURPOSE: To obtain an optical system constitution capable of constituting a camera whose shape is not so different from that of a conventional camera through it is provided with both a photographing device for a photosensitive recording medium and an image pickup device for an image pickup element, and to obtain the optical system constitution capable of preventing the size of the camera from becoming large by making a member common as far as possible though it is provided with both the photographing device for the photosensitive recording medium and the image pickup device for the image pickup element. CONSTITUTION: This camera is provided with a first light splitting mean BS1 splitting a luminous flux passing through a main lens and being made incident into a luminous flux image-formed on the photoosensitive recording medium surface and a luminous flux forming a primary image different from the one on the photosensitive medium surface, a first relay optical system RL1 where the luminous flux from the primary image is made incident, a second light splitting means BS2 splitting the luminous flux outgoing from the first relay optical system RL1 into a luminous flux for picking up an image and a luminous flux for observing a finder, a second relay optical system RL2 cooperating with the first relay optical system RL1 in order to make the luminous flux for observing the finder image-formed on a finder image surface, and a third relay optical system RL3 cooperating with the first relay optical system RL1 in order to make the luminous flux for picking up the image image-forming on the image pickup element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera which splits an incident light beam and forms an optical path which guides it to a photosensitive recording medium, an image pickup device and an optical viewfinder. More specifically, the present invention relates to a structure for forming an optical path in a camera capable of capturing an image with a photosensitive recording medium, for example, a silver salt film, and capturing and recording a moving image or a still image with an image sensor.

[0002]

2. Description of the Related Art Conventionally, various cameras using a silver salt film as a photosensitive recording medium and cameras capable of recording moving images and still images using an image pickup device have been used.
On the other hand, although various cameras having both an image pickup device for a photosensitive recording medium and an image pickup device for an image pickup element have been proposed, few are actually used. One of the reasons for this is that when such a camera is constructed, the
And a member (a member including an optical system) and a space (a space for forming an optical path) that form a camera of three types or three types must be provided in one camera, and therefore the camera becomes large. Since the degree of freedom in arranging the members becomes low and the shape of the camera becomes largely different from that of the camera which is normally used, it is considered that there is a great possibility that the consumer feels uncomfortable. Further, as the image pickup element, an image pickup element whose area of the image pickup surface is considerably smaller than that of a photographing screen of a silver salt film is usually used for reasons such as cost. Therefore, an optical system for photographing a silver salt film and an optical system for photographing must use different magnifications, and it is difficult to make them common. Therefore, the size of the camera becomes larger and the manufacturing cost becomes higher, which is also an obstacle to realization.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a camera having both an image pickup device for a photosensitive recording medium and an image pickup device for an image pickup element, which is not so different in shape from a conventional camera. Is to obtain an optical system configuration capable of configuring. Further, it is to obtain an optical system configuration capable of preventing the camera from becoming huge by using a common member as much as possible while having both an image pickup device for a photosensitive recording medium and an image pickup device for an image pickup element. .

[0004]

In order to achieve the above object, the present invention according to claim 1 divides a light flux which has passed through a main lens and is incident, and guides it to a photosensitive recording medium, an image pickup element and an optical viewfinder. In a camera that forms an optical path, a first light that splits a light beam that has passed through a main lens and is incident into a light beam that forms an image on the surface of a photosensitive recording medium and a light beam that forms a primary image different from the surface of the photosensitive medium. A splitting means, a first relay optical system on which the light flux from the primary image is incident, and a second light flux that splits the light flux emitted from the first relay optical system into a light flux for imaging and a light flux for finder observation. A light splitting unit, a second relay optical system that cooperates with the first relay optical system to form the finder observation light beam on the finder image plane, and the imaging light beam are combined on an image sensor. The first relay light to be imaged Is characterized in that a third relay optical system that cooperates with the system.

According to the present invention of claim 2, in a camera which forms an optical path for splitting a light beam which has passed through the main lens and is incident to lead to the photosensitive recording medium, the image pickup device and the optical finder, the camera passes through the main lens. The first light splitting means for splitting the incident light flux into a light flux which forms an image on the surface of the photosensitive recording medium and a light flux which forms a primary image different from the photosensitive medium surface, and the light flux from the primary image A first relay optical system that forms a secondary image, and a light beam emitted from the first relay optical system is divided into a light beam for imaging and a light beam for finder observation on the object side of the secondary image plane. Second light splitting means for forming a secondary image for imaging and a secondary image for finder observation by means of the above, and second relay optics for forming a light beam from the secondary image for finder observation on the finder image plane. From the system and the secondary image for imaging The focusing the light beam on the imaging device 3
It has a relay optical system of.

Further, the invention of claim 3 is, in a camera which forms an optical path for splitting a light beam which has passed through the main lens and is incident to lead to a photosensitive recording medium, an image pickup element and an optical viewfinder, the light beam passing through the main lens. First light splitting means for splitting the incident light beam into a light beam which forms an image on the surface of the photosensitive recording medium and a light beam which forms a primary image different from the surface of the photosensitive medium, and a light beam from the primary image By dividing the first relay optical system that forms the next image and the light flux emitted from the first relay optical system into a light flux for imaging and a light flux for finder observation on the object side of the secondary image plane. Second light splitting means for forming a secondary image for imaging and a secondary image for finder observation, and a second relay optical system for forming a light flux from the secondary image for imaging on an image sensor. It is characterized by having.

Furthermore, the present invention of claim 4 is a camera for forming an optical path for splitting a light beam which has passed through the main lens and is incident to lead to the photosensitive recording medium, the image pickup device and the optical viewfinder. First light splitting means for splitting the light flux which has passed and entered into a light flux which forms an image on the surface of the photosensitive recording medium and a light flux which forms a primary image different from the surface of the photosensitive medium, and a light flux from the primary image. Second light splitting means for splitting the light beam for imaging into a light beam for finder observation, a second relay optical system for forming the light beam for finder observation on the finder image plane, and the light beam for imaging. And a third relay optical system for forming an image on the image sensor.

Further, according to the present invention of claim 5, in a camera which forms an optical path for splitting an incident light flux to guide it to a photosensitive recording medium, an image pickup device and an optical finder, the first invention receives light from a subject. A main lens, a first light splitting means for splitting the light flux emitted from the first main lens into a light flux for imaging and other light flux, and the above-mentioned light flux for imaging to form an image on the image sensor. A first sub-lens that cooperates with the first main lens, a second main lens that splits the other light flux into a light flux for finder observation and a light flux for photosensitive recording medium, and the light flux for finder observation. To form an image on the image plane of the finder, a second sub-lens that cooperates with the first main lens and the second main lens, and to form a light beam for the photosensitive medium on the surface of the photosensitive recording medium. First main lens and second main It is characterized in that a third of the main lens to lens and cooperate.

On the other hand, according to the present invention of claim 6, in a camera which divides an incident light beam and forms an optical path leading to a photosensitive recording medium, an image pickup element and an optical viewfinder, the first light receiving object receives light. A main lens, a first light splitting unit that splits the light beam emitted from the first main lens into a light beam for finder observation and other light beams, and forms the light beam for finder observation on a finder image plane. Therefore, a first sub-lens that cooperates with the first main lens, a second main lens that splits the other light flux into a light flux for imaging and a light flux for a photosensitive recording medium, and the light flux for imaging. A second sub-lens cooperating with the first main lens and the second main lens to form an image on the image sensor, and the light beam for the photosensitive medium to form an image on the surface of the photosensitive recording medium. First main lens and second main lens It is characterized in that a third main lens's cooperating.

[0010]

According to the first to third aspects of the invention, the image formed by the main lens is formed on the photosensitive recording medium, for example, a silver salt film, and is divided by the first beam splitter to form another primary image. Form. This primary image is reduced through the relay optical system and divided by the second beam splitter to form a finder image and an image for imaging. At that time, the relay optical system for forming the finder image and the image for imaging are formed. An image forming relay optical system is also used at least in part.

According to the invention of claim 4, the image formed by the main lens is formed on the photosensitive recording medium, for example, a silver salt film, and is divided by the first beam splitter to form another primary image. . This primary image is reduced through the relay optical system and divided by the second beam splitter to form a finder image and an image for imaging. At that time, the relay optical system for forming the finder image and the image for imaging are formed. The image forming relay optics function completely independently.

According to the invention of claims 5 to 6, a finder image or an image for imaging is formed by the first main lens and the first sub-lens, and the first main lens, the second main lens and the second main lens are formed. An image for pickup or a finder image is formed by the second sub-lens, and an image for photographing a photosensitive recording medium such as a silver salt film is formed by the first to third main lenses.

[0013]

FIG. 1 shows a first embodiment of the present invention and corresponds to claim 1. In FIG. 1, the main lens T
The light beam incident from L is split into two light beams by the first beam splitter BS1. Of the divided luminous flux,
One forms an optical path to form an image on the film F loaded in the camera. On the other hand, the other of the divided light beams forms the primary image IMG1 at a position different from the film surface. Further, the light flux forming the primary image is guided by the first relay optical system RL1 and then split by the second beam splitter BS2, and then the second relay optical system RL2 and the third relay optical system RL2, respectively. It is incident on RL3.
The light flux emitted from the second relay optical system RL2 forms a secondary image IMGF for finder observation. The light flux emitted from the third relay optical system RL3 forms a secondary image IMGP for imaging. In the above configuration, the relay optical system functions as a reduction optical system for forming a viewfinder image or an image for imaging whose area is smaller than the shooting area of the film F, but a part of the optical system is the first relay optical system. It is shared as the system RL1. Therefore, the reduction optical system and its optical path can be made small as a whole, and as a result, the degree of freedom of arrangement is also improved. Therefore, the size of the camera can be reduced and the camera can be designed in a natural shape.

Next, an actual example of arranging the optical system of the above embodiment in a camera will be described with reference to FIG. In this figure, the main lens is omitted for the sake of simplicity. In FIG. 2, 11 is a semi-transparent mirror installed behind the main lens at an angle of 45 degrees with respect to the optical axis of the main lens,
It constitutes a first beam splitter. This semi-transparent mirror 1
The light flux that has passed through 1 is a shooting image frame 13 formed behind it.
It is projected and imaged on the film F exposed inside. Although the film F is a roll film and is pulled out from the cartridge and reaches the photographing frame 13, the illustration is omitted because it is not directly involved in the configuration of the present invention (each embodiment described later). But the same). On the other hand, the light flux reflected by the semi-transparent mirror 11 travels above the camera to form a primary image 15. The primary image 15 may be an aerial image, or may be an image formed on a focusing plate provided at the position of the image plane (this point also applies to each of the following embodiments. Is).

The light flux forming the primary image goes further upward and is reflected backward by the total reflection mirror 17, and the reflected light is further reflected obliquely forward by the total reflection mirror 19.
The light beam reflected obliquely forward passes through the relay optical system 21 installed obliquely, and is then split by the semi-transparent mirror 23 forming the second beam splitter. The light flux reflected by the semi-transparent mirror 23 travels toward the rear of the camera and enters another relay optical system 25. This light flux forms an image on the image pickup surface 27 of an image pickup device such as a CCD by the action of the two relay optical systems 21 and 25. That is, this image is picked up by the image pickup element and recorded as a moving image or a still image on a magnetic disk, a magnetic tape, an IC card or other various recording media (not shown).

On the other hand, the light flux transmitted through the semi-transparent mirror 23 further advances obliquely forward, is reflected backward by the total reflection mirror 29, and enters another relay optical system 31. This luminous flux is 2
An image is formed as a finder image 33 by the action of the two relay optical systems 21 and 31. This image is observed by the photographer from behind by the eyepiece lens 35.

With the above arrangement, the light beam is bent in the Z shape along the horizontal plane in the vicinity of the upper surface of the camera. Therefore, the camera can have a shape similar to that of a conventionally used camera as shown in FIG. 20, that is, a normal camera using a silver salt film. Therefore, the consumer does not feel uncomfortable and is easily accepted. Further, since the finder image and the image pickup device have a small area with respect to the photographing image frame 13 of the film F, each relay optical system has to reduce the image, as described above. In such a configuration, since the distance from the image plane of the primary image 15 to the incident position of the relay optical system 21 can be long, there is an advantage that a relay optical system having a large reduction rate can be used.

Next, a modification of the configuration of FIG. 2 will be described with reference to FIGS. The configuration of FIG. 3 has two total reflection mirrors 1.
A relay optical system 37 is installed between 7 and 19, and three relay optical systems 18 are provided for the finder image and the image for imaging, respectively.
2 is different from FIG. 2 only in that the images are formed by 21, 31 and 18, 21, 25, and other configurations are the same. In such a configuration, since the relay optical system is divided into a large number, there is an advantage that the degree of freedom in design is higher and the design is easier. The configuration of this modification is also shown in FIG.
It is suitable for use in a camera having a shape like this.

In the configuration of FIG. 4, a relay optical system 37 is installed between two total reflection mirrors 17 and 19 instead of the relay optical system installed between the total reflection mirror 19 and the semitransparent mirror 23. 2 is the only difference from FIG. 2, and other configurations are the same. Since the distance between the two total reflection mirrors 17 and 19 is larger than the distance between the total reflection mirror 19 and the semitransparent mirror 23, the relay optical system 37
The degree of freedom in designing is increased, and the relay optical system can be configured with a small number of constituent lenses. The configuration of this modification is also suitable for use in a camera having a shape as shown in FIG.

The configuration of FIG. 5 is similar to the configuration of the optical system, but the arrangement is significantly different from the above-mentioned configurations. First, the above-mentioned configurations are the same until the light flux forming the primary image is reflected backward by the total reflection mirror 17.
The light flux reflected rearward is incident on the relay optical system 41, further proceeds rearward, and is split by the semitransparent mirror 43. The light beam reflected upward by the semi-transparent mirror 43 is reflected backward by the total reflection mirror 51 and enters the relay optical system 53.
This light flux forms an image on the image pickup surface 55 of the image pickup device by the action of the relay optical systems 41 and 53. On the other hand, the light flux that has passed through the semi-transparent mirror 43 travels further rearward and enters the relay optical system 45, and is imaged as a finder image 47 by the action of the relay optical systems 41 and 45. This image can be observed by the eyepiece lens 49.

With the above construction, the light beam is photographed below the camera, and the optical path for the finder is formed above.
In addition, although each optical system for imaging is shown large in the drawing for easy viewing, the area of the imaging surface is considerably smaller than the image frame of the film, so it is actually smaller and the light flux for the viewfinder is smaller. Can be provided in the vicinity of. Therefore, the camera can have a shape similar to that of a conventionally used camera, that is, a normal movie video camera, as shown in FIG. Therefore, the consumer does not feel uncomfortable and is easily accepted.

FIG. 6 shows a second embodiment of the present invention and corresponds to claim 3. In FIG. 6, the main lens T
The light beam incident from L is split into two light beams by the first beam splitter BS1. Of the divided luminous flux,
One forms an optical path to form an image on the film F loaded in the camera. On the other hand, the other of the divided light beams forms the primary image IMG1 at a position different from the film surface. Further, the light flux forming the primary image is guided by the first relay optical system RL1 and then split by the second beam splitter BS2. One of the divided luminous fluxes forms the secondary image IMG2 for finder observation as it is, and the other luminous flux forms another secondary image IMG2. Secondary image IM
The light flux forming G2 is imaged as a secondary image IMGP for imaging by the second relay optical system RL2.

This embodiment is more effective when the size of the viewfinder image is larger than that of the image pickup device. The first relay optical system RL1 reduces the size of the viewfinder image once, and then the size of the image pickup device is further increased. It has a two-tiered structure that reduces the size. Therefore, since the relay optical system functions as an optical system that functions independently, there is an advantage that it is not necessary to perform a complicated design even though the relay optical system also serves as a part of the relay optical system (reduction optical system). is there.

Next, an actual example of arranging the optical system of the above embodiment in a camera will be described with reference to FIG. Also in this figure, the main lens is omitted. In FIG. 7, reference numeral 61 denotes a semi-transparent mirror which is installed behind the main lens at an angle of 45 degrees with respect to the optical axis of the main lens, and constitutes a first beam splitter. The light flux that has passed through the semi-transparent mirror 61 is projected and imaged on the film F that is exposed in the shooting image frame 63 formed behind it. On the other hand, the semi-transparent mirror 6
The light flux reflected by 1 travels above the camera to form a primary image 65.

The light flux forming the primary image goes further upward and is reflected backward by the total reflection mirror 67, and this reflected light enters the relay optical system 69. The light flux emitted from the relay optical system 69 is split by the semitransparent mirror 71. Of the split light fluxes, the light flux that has passed through the semi-transparent mirror 71 is imaged as a finder image 73 by the action of the relay optical system 69. This image is observed by the photographer through the eyepiece lens 75. On the other hand, the light beam reflected by the semi-transparent mirror 71 above the camera forms a secondary image 77 by the action of the relay optical system 69. The light flux forming this secondary image further advances to the upper side of the camera, is reflected back by the total reflection mirror 79, and is imaged on the image pickup surface 83 of the image pickup element by another relay optical system 81. This embodiment is also applicable to the camera having the structure shown in FIG.

FIG. 8 shows a third embodiment of the present invention and corresponds to claim 4. In FIG. 8, the main lens T
The light beam incident from L is split into two light beams by the first beam splitter BS1. Of the divided luminous flux,
One forms an optical path to form an image on the film F loaded in the camera. On the other hand, the other of the divided light beams forms the primary image IMG1 at a position different from the film surface. Further, the light flux forming this primary image is split by the second beam splitter BS2. One of the divided light beams is imaged as a secondary image IMGF for finder observation by the first relay optical system RL1, and the other light beam is imaged as a secondary image IMGP for imaging by the second relay optical system RL2. To be done. The configuration of this embodiment is extremely simple in design because the relay optical system for forming the finder image and the relay optical system for forming the image for imaging are each independently configured.

Next, an actual example of arranging the optical system of the above embodiment in a camera will be described with reference to FIG. Also in this figure, the main lens is omitted. In FIG. 9, reference numeral 91 denotes a semi-transparent mirror which is installed behind the main lens at an angle of 45 degrees with respect to the optical axis of the main lens, and constitutes a first beam splitter. The light flux that has passed through the semi-transparent mirror 91 is projected and imaged on the film F that is exposed in the shooting image frame 93 formed behind it. On the other hand, the semi-transparent mirror 91
The light flux reflected by is directed above the camera to form a primary image 95.

The light flux forming the primary image goes further upward and is reflected backward by the total reflection mirror 97, and this reflected light is further reflected obliquely forward by the total reflection mirror 99.
The light rays reflected obliquely forward are split by the semitransparent mirror 101. The light flux reflected by the semi-transparent mirror 101 is directed to the rear of the camera and enters the relay optical system 103. This light flux forms an image on the image pickup surface 105 of the image pickup element by the action of the relay optical system 103.

On the other hand, the light flux transmitted through the semi-transparent mirror 101 further advances obliquely forward, is reflected backward by the total reflection mirror 107, and enters another relay optical system 109. This light flux is imaged as a finder image 111 by the action of the relay optical system 109. This image is observed by the photographer through the eyepiece lens 113. This arrangement example is suitable for a camera having a configuration as shown in FIG.

Next, a modification of the above arrangement example will be described with reference to FIG. In FIG. 10, the light flux forming the primary image is split by the semi-transparent mirror 115 instead of the total reflection mirror.
The light flux reflected rearward by the semi-transparent mirror 115 is imaged as a finder image 119 by the relay optical system 117. This image is observed by the eyepiece lens 121. On the other hand, the light flux transmitted through the semi-transparent mirror 115 travels further upward, is reflected backward by the total reflection mirror 123, and is imaged on the image pickup surface 127 of the image pickup element by the relay optical system 125.
This modified example is suitable for a camera having a configuration as shown in FIG.

FIG. 11 shows a fourth embodiment of the present invention. In FIG. 11, the light beam incident from the main lens TL is split into two light beams by the first beam splitter BS1. One of the divided luminous fluxes forms an optical path for forming an image on the film F loaded in the camera. On the other hand, the other of the divided light beams forms the primary image IMG1 at a position different from the film surface. Further, the light flux forming the primary image is imaged again by the first relay optical system RL1 to form the secondary image IMG2. This secondary image is observed via the second beam splitter BS2 on the one hand by the eyepiece and on the other hand is again imaged by the second relay optical system RL2 as a tertiary image IMGP for imaging. Similar to the second embodiment, this embodiment also performs a two-step reduction in which an image that has been once reduced is further reduced, so that the relay optical system (reduction optical system) can also be used as a part of it. Design is extremely easy. Further, the reduction ratio of the second relay optical system RL2 itself can be reduced.

Next, an actual example of arranging the optical system of the above embodiment in a camera will be described with reference to FIG. Also in this figure, the main lens is omitted. In FIG. 12, 131
Is 45 behind the main lens with respect to the optical axis of the main lens.
It is a semi-transparent mirror installed at an angle of degrees and constitutes a first beam splitter. The light flux that has passed through the semi-transparent mirror 131 is projected and imaged on the film F exposed in the photographing image frame 133 formed behind it. on the other hand,
The light flux reflected by the semi-transparent mirror 131 heads above the camera to form a primary image 135.

The light flux forming the primary image goes further upward and is reflected backward by the total reflection mirror 137. This reflected light is further reflected by the total reflection mirror 139 in the lateral direction of the camera and in the diagonally forward direction. It The light beam reflected laterally and diagonally forward passes through the relay optical system 141, and then is reflected by the total reflection mirror 143 to the rear of the camera. The reflected light beam is subjected to the secondary image 14 by the action of the relay optical system 141.
The image is formed as 5. A semi-transparent mirror 147 and an eyepiece lens 149 are installed behind the secondary image 145.
To be observed by the photographer. On the other hand, the semi-transparent mirror 14
The light flux reflected by 7 is in the lateral direction of the camera (the above total reflection mirror 1
39), and an image is formed on the image pickup surface 153 of the image pickup device by the relay optical system 151 installed in the horizontal direction. In this configuration, the optical path from the total reflection mirror 139 to the total reflection mirror 143 and the optical path from the semi-transparent mirror 147 to the image sensor are set to be substantially horizontal. That is, the arrangement is well suited to the shape of the camera having the configuration shown in FIG.

FIG. 13 shows a fifth embodiment of the present invention and corresponds to claim 2. In FIG. 13, the light beam incident from the main lens TL is the first beam splitter BS.
It is divided into two light fluxes by 1. One of the divided luminous fluxes forms an optical path for forming an image on the film F loaded in the camera. On the other hand, the other of the divided light beams forms the primary image IMG1 at a position different from the film surface. Further, the light flux forming the primary image is guided by the first relay optical system RL1, and after being split by the second beam splitter BS2, the first secondary image IMG21 and the second secondary image IMG22, respectively. To form.
The light fluxes forming the two secondary images respectively enter the second relay optical system RL2 and the third relay optical system RL3. The luminous flux emitted from the second relay optical system RL2 forms a tertiary image IMGF for finder observation. In addition, the third
The light flux emitted from the relay optical system RL3 forms the tertiary image IMGP for imaging. In the configuration of this embodiment, a part of the relay optical system (reduction optical system) is also used, but since a reduced image is once made, it is further reduced according to the size of the finder image and the image pickup surface. There is an advantage that the design of the relay optical system is simple and that each relay optical system has a small reduction rate.

Next, an actual example of arranging the optical system of the above embodiment in the camera will be described with reference to FIG. In this figure, the main lens is omitted for the sake of simplicity.
In FIG. 14, reference numeral 161 denotes a semi-transparent mirror that is installed behind the main lens at an angle of 45 degrees with respect to the optical axis of the main lens, and constitutes a first beam splitter. The light flux transmitted through the semi-transparent mirror 161 is projected and imaged on the film F exposed in the photographing frame 163 formed behind the semi-transparent mirror 161. On the other hand, the light flux reflected by the semi-transparent mirror 161 heads above the camera and forms a primary image 165.

The light flux forming the primary image goes further upward and is reflected backward by the total reflection mirror 167. This reflected light passes through the relay optical system 169 and is then split by the semitransparent mirror 171. The light flux that has passed through the semi-transparent mirror 171 travels toward the rear of the camera, forms a secondary image 173, and then enters another relay optical system 175. This light flux is imaged as a finder image 177 by the action of the relay optical system 175. Eyepiece 17 with this image installed behind it
9 Observed by the photographer. On the other hand, the light flux reflected upward by the semi-transparent mirror 171 once forms a secondary image 181, then is reflected backward by the total reflection mirror 183 and enters another relay optical system 185. This light flux forms an image on the image pickup surface 187 of the image pickup element by the action of the relay optical system 185. This embodiment is suitable for a camera having the structure shown in FIG.

Next, a further embodiment of the present invention will be described.
In each of the above embodiments, the light beam split by the first beam splitter forms a primary image equivalent to the film surface, and the primary image is reduced by a relay optical system and used for finder observation and imaging. It was what was there. On the other hand, in the embodiments described below, the lens corresponding to the main lens is composed of a plurality of lenses, the light flux is divided between the lenses, and an image for imaging or finder observation is formed after the division. A lens suitable for is further arranged. In other words, not only an image formed on the film surface, but also an image used for imaging and an image used for finder observation are formed as primary images.

FIG. 15 shows a sixth embodiment of the present invention and corresponds to claims 5 and 6. In FIG. 15, the light beam incident through the first main lens ML1 is split by the first beam splitter BS1. One of the split light beams enters the second beam splitter BS2 via the second main lens ML2 and is further split. One of the light beams split by the second beam splitter BS2 forms an image on the film surface F via the third main lens ML3 and is photographed. On the other hand, the other of the light beams split by the first beam splitter BS1 forms an image IMGP for imaging via the first sub-lens SL1. The other of the light beams split by the second beam splitter BS2 is imaged as a finder observation image IMGF via the second sub-lens SL2 and is observed by the eyepiece. Alternatively, the configuration is reversed, and the light beam split by the first beam splitter BS1 is used for finder observation, and the second beam splitter B
The light flux divided by S2 may be used for imaging.

As can be understood from the above description, the first to third main lenses ML1, ML2, M are provided on the film surface.
L3 cooperates to function as one imaging optical system, and the first main lens ML1 and the first sub-lens SL1 cooperate to form one imaging optical system on the imaging surface (or film image surface). Acting as. Further, the first and second main lenses ML1 and ML2 and the second sub-lens SL2 act as one imaging optical system on the film image surface (or the imaging surface). As described above, in this embodiment, since the secondary image and the tertiary image are not formed, the finder image and the image for imaging can be formed with a relatively short optical path, which can contribute to the downsizing of the camera.

FIG. 16 is an actual example in which the optical system of the above embodiment is arranged in a camera. In FIG. 16, the first semi-transparent mirror 203, the second main lens 205, which are arranged at an angle of 45 degrees with respect to the optical axis, and the second main lens 205, which are arranged at an angle of 45 degrees with respect to the optical axis, are arranged behind the first main lens 201. The second semi-transparent mirror 207,
The third main lens 209 is sequentially arranged, and the film F is exposed in the shooting image frame 211 behind the third main lens 209. Therefore, the light fluxes that have passed through these optical systems are the first to third main lenses 2
01, 205, 209 forms an image on the film surface,
To be photographed.

The light beam reflected by the first semi-transparent mirror 203 is directed to the upper side of the camera, is bent backward by the total reflection mirror 213, and is incident on the first sub lens 215.
The light flux emitted from the first sub-lens 215 is reflected upward by a total reflection mirror 217 installed in the rear and forms a finder image 219. The light flux forming this image is reflected by a total reflection mirror 221 provided above, and then observed through an eyepiece lens provided behind it. On the other hand, the light flux reflected by the second semi-transparent mirror 207 also goes to the upper side of the camera and is reflected backward by the total reflection mirror 225. The reflected light flux is the second sub lens 227.
An image is formed on the image pickup surface 229 of the image pickup device via the image pickup device. This embodiment is suitable for a camera having the structure shown in FIG. In order to facilitate understanding, the total reflection mirrors 217 and 2
Although 25 is shown separately, in practice both can be placed back-to-back and can be placed in a smaller space.

FIG. 17 shows a modification of the arrangement. In this arrangement, the image formation on the film surface is the same as in the example of FIG. In FIG. 17, the light flux reflected upward from the first semi-transparent mirror is reflected to the rear of the camera by the total reflection mirror 231, and enters the first sub lens 233. The light flux emitted from the first sub-lens 233 forms an image on the image pickup surface 235 of the image pickup device. On the other hand, the light flux reflected upward by the second semi-transparent mirror is reflected backward by the total reflection mirror 237 and enters the second sub lens 239. The light flux emitted from the second sub-lens 239 is the image plane 2 for finder observation.
The image is formed at 41 and is observed from the rear through the eyepiece lens 243.

FIG. 18 shows a further different embodiment, in which the main lens is made common and thereafter the film is photographed through the teleconverter lens, and the viewfinder is observed or imaged through the wide converter lens. Form an image of. Although illustration of the finder optical system portion and the image pickup portion is omitted in this figure, the above-described embodiments and other configurations can be arbitrarily combined. In this embodiment, since the image of the size to be photographed on the film and the image of the size of the image of the size of the image pickup device or the finder image are formed, and the image is enlarged or reduced respectively, This has the advantage that the main lens and each converter lens can be designed easily.

FIG. 19 shows an example of the case where the optical system of the above embodiment is arranged in the camera. In FIG. 19, a semi-transparent mirror 303 and a teleconverter lens 305, which are arranged at an angle of 45 degrees with respect to the optical axis, are arranged behind the main lens 301, and behind the main lens 301, there is a film F in a photographing frame 307.
Is exposed. Therefore, the light flux that has passed through these optical systems forms an image on the film surface by the main lens 301 and the teleconverter lens 305, and is photographed. Semi-transparent mirror 3
The luminous flux reflected by 03 goes to the upper side of the camera,
The light is bent backward by the total reflection mirror 309 and is incident on the wide converter lens 311. Therefore, the main lens 3
01 and the wide converter lens 311 form an image, and the image is used for finder observation and imaging.

In the above embodiments and arrangement examples, the main lens, the sub lens, the relay optical system, and each converter lens are shown as one unit in the drawing, but actually, they are usually composed of a plurality of lenses. To be done. Also, other,
The light-tight structure, which is an essential component of the camera, is also omitted in the above description. Further, the configurations of the diaphragm, shutter, etc. are not special ones, so that the description thereof is omitted. Further, the main lens may be removable from the camera or fixed to the camera, except for the one shown in FIG. 15 (divided into a plurality).

[0046]

According to the first to third aspects of the present invention, the image formed by the main lens is formed on the photosensitive recording medium, for example, a silver salt film, and is divided by the first beam splitter so that another primary beam is formed. Form an image. This primary image is reduced through the relay optical system and split by the second beam splitter to form a finder image and an image for imaging.
At that time, the relay optical system for forming a finder image and the relay optical system for forming an image for imaging are used at least partially. Therefore, the relay optical system is provided in order to form two types of images having different sizes from the image formed for the photosensitive recording medium, but the relay optical system can be the smallest.

According to the invention of claim 4, the image formed by the main lens is formed on the photosensitive recording medium, for example, a silver salt film, and is divided by the first beam splitter to form another primary image. . This primary image is reduced through the relay optical system and divided by the second beam splitter to form a finder image and an image for imaging. At that time, the relay optical system for forming the finder image and the image for imaging are formed. The image forming relay optics function completely independently. Therefore,
Relay optics can be constructed with a very simple design.

According to the invention of claims 5 to 6, a finder image or an image for imaging is formed by the first main lens and the first sub-lens, and the first main lens, the second main lens and the second main lens are formed. An image for pickup or a finder image is formed by the second sub-lens, and an image for photographing a photosensitive recording medium such as a silver salt film is formed by the first to third main lenses. Therefore, since the secondary image and the tertiary image are not formed, the size of the optical system for forming the image for imaging and the viewfinder image can be reduced.

[Brief description of drawings]

FIG. 1 is a structural explanatory view showing a first embodiment of the present invention.

FIG. 2 is a perspective view showing an arrangement example of the first embodiment.

FIG. 3 is a perspective view showing a modification of the arrangement of the first embodiment.

FIG. 4 is a perspective view showing a second modification of the arrangement of the first embodiment.

FIG. 5 is a perspective view showing a third modification of the arrangement of the first embodiment.

FIG. 6 is a structural explanatory view showing a second embodiment of the present invention.

FIG. 7 is a perspective view showing an arrangement example of the second embodiment.

FIG. 8 is a structural explanatory view showing a third embodiment of the present invention.

FIG. 9 is a perspective view showing an arrangement example of the third embodiment.

FIG. 10 is a perspective view showing a modification of the arrangement of the third embodiment.

FIG. 11 is a structural explanatory view showing a fourth embodiment of the present invention.

FIG. 12 is a perspective view showing an arrangement example of the fourth embodiment.

FIG. 13 is a structural explanatory view showing a fifth embodiment of the present invention.

FIG. 14 is a perspective view showing an arrangement example of the fifth embodiment.

FIG. 15 is a structural explanatory view showing a sixth embodiment of the present invention.

FIG. 16 is a perspective view showing an arrangement example of the sixth embodiment.

FIG. 17 is a perspective view showing a modification of the arrangement of the sixth embodiment.

FIG. 18 is a structural explanatory view showing a seventh embodiment of the present invention.

FIG. 19 is a perspective view showing an arrangement example of the seventh embodiment.

FIG. 20 is an external view of a camera equipped with the optical system of the present invention.

FIG. 21 is another external view of a camera equipped with the optical system of the present invention.

[Explanation of symbols]

 BS1 First light splitting means BS2 Second light splitting means RL1 First relay optical system RL2 Second relay optical system RL3 Third relay optical system ML1 First main lens ML2 Second main lens ML3 Third Main lens SL1 First sub lens SL2 Second sub lens

Claims (6)

[Claims] 1. In a camera that divides a light beam that has passed through a main lens and forms an optical path that leads to a photosensitive recording medium, an image sensor, and an optical viewfinder, a light beam that has passed through the main lens and is incident First light splitting means for splitting a light beam which forms an image on the surface of the recording medium and a light beam which forms a primary image different from the surface of the photosensitive medium, and a first relay optical system on which the light beam from the primary image enters. And second light splitting means for splitting the light flux emitted from the first relay optical system into a light flux for imaging and a light flux for finder observation, and the light flux for finder observation is imaged on a finder image plane. Therefore, a second relay optical system that cooperates with the first relay optical system, and a third relay optical system that cooperates with the first relay optical system to form an image of the imaging light flux on an image sensor. And a system The optical system of the camera. 2. In a camera that divides a light beam that has passed through a main lens to form an optical path that leads to a photosensitive recording medium, an image sensor, and an optical viewfinder, a light beam that has passed through the main lens and is incident First light splitting means for splitting a light beam that forms an image on the surface of the recording medium and a light beam that forms a primary image different from the surface of the photosensitive medium, and a first light beam that forms a secondary image by the light beam from the primary image. And a secondary image for imaging by dividing the light beam emitted from the first relay optical system into a light beam for imaging and a light beam for finder observation on the object side of the secondary image plane. Second light splitting means for forming a secondary image for finder observation, a second relay optical system for forming a light beam from the secondary image for finder observation on a finder image plane, and the second image pickup device for imaging Form the light flux from the next image on the image sensor The third optical system of the camera characterized by comprising a relay optical system, the causing. 3. In a camera that divides a light beam that has passed through a main lens and forms an optical path that leads to a photosensitive recording medium, an image sensor, and an optical viewfinder, a light beam that has passed through the main lens and is incident First light splitting means for splitting a light beam that forms an image on the surface of the recording medium and a light beam that forms a primary image different from the surface of the photosensitive medium, and a first light beam that forms a secondary image by the light beam from the primary image. And a secondary image for imaging by dividing the light beam emitted from the first relay optical system into a light beam for imaging and a light beam for finder observation on the object side of the secondary image plane. A second light splitting means for forming a secondary image for finder observation, and a second relay optical system for forming a light beam from the secondary image for imaging on an image sensor. And the optical system of the camera. 4. A camera, which forms an optical path that divides a light beam that has passed through a main lens and is incident to lead to a photosensitive recording medium, an image sensor, and an optical viewfinder, First light splitting means for splitting a light beam which forms an image on the surface of the recording medium and a light beam which forms a primary image different from the surface of the photosensitive medium, and a light beam for imaging the light beam from the primary image and for finder observation Second light splitting means for splitting the light flux for the finder observation, a second relay optical system for focusing the light flux for finder observation on the finder image plane, and a second light for focusing the light flux for imaging on the image sensor. A relay optical system of 3, and an optical system of a camera. 5. A camera for dividing an incident light beam to form an optical path leading to a photosensitive recording medium, an image pickup device and an optical viewfinder, a first main lens for receiving light from a subject, and the first main lens described above. First light splitting means for splitting the light flux emitted from the main lens into a light flux for imaging and other light flux, and the first main lens for forming the light flux for imaging on the image sensor. A first sub-lens, a second main lens that splits the other light flux into a light flux for finder observation and a light flux for a photosensitive recording medium, and forms the light flux for finder observation on a finder image plane. Therefore, a second sub-lens that cooperates with the first main lens and the second main lens, and the first main lens and the second main lens to form an image of the light beam for the photosensitive medium on the surface of the photosensitive recording medium. 3rd main lens that cooperates with the main lens of An optical system for a camera, which is characterized by including 6. A camera for dividing an incident light flux to form an optical path leading to a photosensitive recording medium, an image sensor and an optical viewfinder, a first main lens for receiving light from a subject, and the first lens described above. First light splitting means for splitting the light beam emitted from the main lens into a light beam for finder observation and another light beam; and the first main lens for forming the light beam for finder observation on a finder image plane A first sub-lens that cooperates, a second main lens that splits the other light flux into a light flux for imaging and a light flux for a photosensitive recording medium, and the light flux for imaging is imaged on an image sensor. Therefore, a second sub-lens that cooperates with the first main lens and the second main lens, and the first main lens and the second main lens to form an image of the light beam for the photosensitive medium on the surface of the photosensitive recording medium. 3rd main lens that cooperates with the main lens of An optical system for a camera, which is characterized by including