JPH10260471A - Multifocus camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a photographing lens to be switched without requiring a movable mechanism, to miniaturize a camera and to reduce the cost thereof by providing the camera with a selection means selecting luminous flux guided to an image pickup part out of the plural luminous flux and including a beam splitter in the selection means. SOLUTION: This camera is provided with the polarizing beam splitter 61 guiding the luminous flux emitted from the photographing lenses 8 and 10 in the direction of one CCD 13 and a reflection mirror 63 corresponding to the optical axis of the lens 8. Besides, a polarizing plate 62 is freely rotatably arranged at a slit aperture between the splitter 61 and the CCD 13. Then, a P polarized light beam from the lens 8 and an S polarized light beam from the lens 10 arrive at the plate 62 by the splitter 61. According to the angle position of the plate 62, the light beam arriving at the CCD 13 is selected. Thus, the angle of the plate 62 is decided by operating an operation knob and the switching of the lenses 8 and 10 is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multifocal camera having a plurality of photographing lenses having different focal lengths.

[0002]

2. Description of the Related Art Conventionally, a multifocal camera changes a focal length by moving an auxiliary lens in and out of an optical axis of a main lens (for example, Japanese Utility Model Laid-Open No. 2-119632).
Japanese Patent Application Laid-Open No. HEI 2-119633 is known in which a lens is switched by rotating a mirror arranged on the optical axis.

[0003]

However, in the above-mentioned multifocal camera, a movable mechanism for moving a lens and a mirror is required for switching a photographing lens, and the configuration becomes complicated, and the camera becomes large. And increased costs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and makes it possible to switch a photographing lens without using a movable mechanism by using polarized light, to reduce the size and cost. It is an object of the present invention to provide a multi-focus camera aiming at.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, a plurality of photographing lens systems having different incident light beams and different focal lengths are combined with light beams emitted from the photographing lens systems. A multi-focal camera including a beam splitter, comprising: an imaging unit for imaging; and selecting means for selecting a light beam guided to the imaging unit from a plurality of light beams emitted from the imaging lens system. It is. In this configuration, one of the light beams emitted from the photographing lens is selected by the beam splitter and guided to the photoelectric conversion element, so that the photographing lens can be switched without requiring a movable mechanism.

According to a second aspect of the present invention, in the multifocal camera according to the first aspect, the selecting means includes a polarizing means for polarizing light, and the light beam guided to the imaging section is polarized by the polarizing means. It is a luminous flux. In this configuration, the photographing lens can be switched with a simple configuration using the polarizing means.

According to a third aspect of the present invention, there is provided the multifocal camera according to the second aspect, wherein the selecting means polarizes the light into P-polarized light and S-polarized light according to the photographing lens, and selects between P-polarized light and S-polarized light. And a variable polarization filter. In this configuration, lens switching can be performed using a polarization variable filter.

According to a fourth aspect of the present invention, in the multifocal camera according to the second aspect, the polarizing means is a polarizing beam splitter.

According to a fifth aspect of the present invention, in the multifocal camera according to the second aspect, the polarizing means is provided in front of or behind the taking lens.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 show a bifocal camera according to the first embodiment. FIG. 1 is an external view of the camera. The bifocal electronic camera 1 includes a camera body 2 having a square shape, an imaging block 3 for photographing, and an LCD 4 for displaying a photographed image. Camera body 2
Are provided with a release button 6, a power switch (not shown), a storage device including a control circuit and a memory card, a battery power supply, and the like. The imaging block 3 includes two photographing lenses 8, 10 (T: tele, W:
Wide) and a CCD 13 which receives light beams emitted from these photographing lenses and converts the optical image into an electric signal.
(Imaging unit: FIG. 2) and various optical members for switching these photographing lenses, that is, switching the focal length (means for selecting a light flux guided to the imaging unit) are provided. Further, a polarizing plate rotation operation lever 6 for switching the focal length is provided.
2a is provided so as to be exposed from the slit opening 12g.

FIG. 2 is an exploded perspective view of the imaging block 3. The housing of the imaging block 3 is formed by the lens / mirror holding unit 12 and the cover unit 15. The taking lenses 8 and 10 are housed in the concave portions 18 and 20 of the lens / mirror holding portion 12 as lens blocks. The CCD 13 is provided at a position of the lens / mirror holding unit 12 facing the optical axis of the taking lens 10. A polarizing beam splitter 61 (polarizing means) for guiding a light beam emitted from the photographing lenses 8 and 10 toward one CCD 13 is provided by the photographing lens 10 and the CCD 13.
And a reflection mirror 63 is provided corresponding to the optical axis of the taking lens 8. The reflecting mirror 63 and the polarizing beam splitter 61 have a function of bending an image forming light beam in a photographing optical path from the photographing lens 8 to the CCD 13, and the polarizing beam splitter 61 reflects P-polarized light as shown in FIG. , S-polarized light is transmitted. Further, the polarization beam splitter 61 and the CCD 13
A polarizing plate 62 (polarization variable filter) is rotatably provided in the slit opening 12g between the slit opening 12g. The polarizing beam splitter 61 and the polarizing plate 62 constitute a lens switching unit that switches the taking lens.

Since the optical system of the imaging block 3 is configured as described above, the polarization beam splitter 61
The P-polarized light from the photographing lens 8 and the S-polarized light from the photographing lens 10 reach the polarizing plate 62,
Light that reaches the CCD 13 is selected according to the angular position of (2). Therefore, the angle of the polarizing plate 62 is determined by rotating the operation knob 63 by 90 °, and the photographing lenses 8 and 10 are rotated.
Can be switched.

FIG. 4 shows a configuration of an optical system of an image pickup block 3 according to another embodiment. In this example, the taking lens 8,
Before 10, polarizing filters 65 and 66 (polarizing means) that are arranged at different angles to polarize to P-polarized light and S-polarized light
Is provided. Then, instead of the polarization beam splitter 61, a half mirror 64 is provided at that position. Also in this configuration, the light reaching the CCD 13 can be selected by rotating the polarizing plate 62 by 90 °, so that the photographing lenses 8 and 10 can be selected.

FIG. 5 shows a configuration of an optical system of the imaging block 3 according to an application example. In this example, the taking lenses 8 and 10
Before, the movable light shielding plate 67 is provided in place of the polarization filters 65 and 66 in the embodiment of FIG. This light shielding plate 67
Is moved, the light reaching the CCD 13 can be selected, and accordingly, the photographing lenses 8 and 10 can be selected.

FIG. 6 is a block diagram of a control circuit of the bifocal electronic camera 1. The control circuit has a CPU 41 and a power supply 42 for controlling the entire camera. The CPU 41 receives operation signals from the power switch 5 and the release switch 6 and controls the camera operation.
, A captured image is displayed on an LCD 4 serving as a display device, and a storage device 4 such as a memory card is received.
3 is stored.

In the bifocal electronic camera 1 according to the various embodiments described above, the photographing lenses 8 having different focal lengths,
Any one of the light beams emitted from the lens 10 is guided to the CCD 13 by using a polarizing means including a beam splitter 61 and the like and a polarization variable filter, and the photographing lenses 8 and 10 can be selected. It does not require a complicated movable mechanism for driving the mirror and the mirror, has a relatively simple configuration, and can reduce the size and cost of the camera. Further, as an imaging medium of the imaging unit, in addition to the photoelectric conversion element,
It may be a silver halide film.

[0017]

As described above, according to the first or second aspect of the present invention, the light beam emitted from the photographing lens is selected by the beam splitter, guided to the image pickup unit, and the photographing lens is switched. As a result, the camera can be reduced in size and cost without requiring a complicated movable mechanism.

Further, according to the second to fifth aspects of the present invention, since the photographing lens can be switched using the polarization variable filter, the structure can be simpler than that of a conventional lens or mirror. The same effect as the first aspect is obtained.

[Brief description of the drawings]

FIG. 1 is an external view of a bifocal electronic camera according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of an imaging block.

FIG. 3 is a diagram showing a configuration of an optical system from a photographing lens to a CCD.

FIG. 4 is a diagram showing a configuration of an optical system according to another embodiment.

FIG. 5 is a diagram showing a configuration of an optical system according to still another embodiment.

FIG. 6 is a block diagram of a control circuit of the camera.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Two focus electronic camera 8, 10 Photographing lens 13 CCD (image pick-up part) 61 Polarization beam splitter (polarization means) 62 Polarization plate (polarization variable filter) 63 Reflection mirror 64 Half mirror 65, 66 Polarization filter (polarization means)

Continued on the front page (72) Inventor Tetsuo Kono 2-3-113 Azuchicho, Chuo-ku, Osaka City Inside Osaka International Building Minolta Co., Ltd. (72) Hiroyuki Matsumoto 2-3-13-Azuchicho, Chuo-ku, Osaka Osaka Kokusai Building Minolta Co., Ltd.

Claims (5)

[Claims] 1. A plurality of photographing lens systems having different incident light fluxes and different focal lengths; an imaging unit for forming an image of a light beam emitted from the photographing lens system; and a plurality of light beams emerging from the photographing lens system. A multi-focal camera, comprising: selecting means for selecting a light flux guided to the imaging unit from among the above, wherein the selecting means includes a beam splitter. 2. The multi-focal point according to claim 1, wherein the selection unit includes a polarization unit that polarizes light, and the light beam guided to the imaging unit is a light beam polarized by the polarization unit. camera. 3. The method according to claim 1, wherein the selecting unit is a P-type lens.
3. The multifocal camera according to claim 2, comprising a polarizing means for polarizing into polarized light and S-polarized light, and a polarization variable filter capable of selecting between P-polarized light and S-polarized light. 4. The multifocal camera according to claim 2, wherein said polarizing means is a polarizing beam splitter. 5. The multifocal camera according to claim 2, wherein said polarizing means is provided in front of or behind a taking lens.