JP2606378B2 - Close-up device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a close-up device such as a camera in which an objective lens system and an optical finder are separately provided.

[Summary of the Invention]

The prism that directs the optical axis of the objective lens system to the subject on the optical axis of the optical viewfinder and the close-up lens are integrated so that the image viewed through the viewfinder and the captured image obtained through the objective lens system do not deviate during close-up shooting. This is a close-up device that enables photographing as seen through the viewfinder.

[Conventional technology]

When a subject is photographed using a camera, an image forming range of the subject on a light receiving surface such as a film or a solid-state image sensor such as a CCD in the camera is usually confirmed by a finder. If the size of the light receiving surface is constant, the image forming range is determined by the focal length of the objective lens constituting the optical system for photographing by the camera and the distance to the subject.

The viewfinder can be broadly classified into a viewfinder which directly determines an image formation range by observing a subject by the objective lens optical system, and a viewfinder which indirectly determines an image formation range using an auxiliary lens or frame. The former is used, for example, in so-called single-lens reflex cameras, and the latter is
It is frequently used for simple cameras. A conventional electronic still camera using the latter finder will be described with reference to FIG.

FIG. 4 is a plan view showing the viewfinder 8 of the electronic still camera 2, the objective lens optical system 21 for photographing, and the recording system. In an outer case 4 of the electronic still camera 2, a CCD 26 having an optical system 21 for photographing composed of a plurality of objective lenses 21a, a finder 8 having an optical system composed of a plurality of lenses 8a, and a light receiving surface 26a. And a recording unit including a recording unit 27. Optical system for shooting 21
Has a fixed focus configuration, and can cover a range where the distance x between the front surface 3 of the camera 2 and the subject 5 is relatively short (for example, 1.5 m) to long distance. The optical system of the viewfinder 8 is configured such that the image formation range of the subject 5 by the viewfinder 8 matches the image formation range of the subject 5 on the light receiving surface 26a.

The light from the subject 5 forms an image on the light receiving surface 26a of the CCD 26 by the optical system 21 and is converted into an electric signal.
It is recorded on a magnetic recording medium (not shown) or the like. Light receiving surface 26a
The image formation range of the subject 5 in the above can be visually recognized indirectly by the finder 8. In this case, even if the distance x changes, it is equal to or longer than the above-described relatively short distance (for example, 1.5 m).
Parallax (parallax) generated between the optical system 21 and the finder 8 does not pose a practical problem.

However, by adding a macro lens to the camera as described above, the subject 5 at a short distance can be moved to the distance x (for example, x
(= 50 cm), parallax occurs between the optical system 21 and the finder 8. This is because the ratio (y / x) of x to the distance y between the optical axis a of the optical system 21 and the optical axis b of the optical system of the finder 8 increases.

In order to correct such parallax, various methods can be considered. In FIG. 4, the macro lens adapter 33 containing the macro lens 31 and the prism 32 is attached to the front surface 3 of the electronic still camera 2. This is done at the same time as adding a macro lens and correcting parallax. In this case, the parallax is corrected by matching the image forming range obtained by the finder 4 combined with the prism 32 to the image forming range of the subject 5 obtained by the optical system 21 combined with the macro lens 31.

[Problems to be solved by the invention]

However, such a method of mounting an adapter requires an adapter 33 having a macro lens 31 and a prism 32 outside the outer case 4 of the camera. Will not fit. In addition, there is an inconvenience that the adapter 33 must be carried and attached whenever necessary.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a close-up apparatus in which parallax generated between an optical system for photographing and an optical system of a finder is corrected with a simple configuration.

[Means for solving the problem]

In order to achieve the above object, a close-up device according to the present invention includes:
It has a close-up lens 1 that can be inserted into an objective lens system 21. The close-up lens 1 is attached to a subject 5 on an optical axis b of an optical finder 8 having an optical axis b parallel to the objective lens system optical axis a. It is characterized in that it is integrated with a prism that deflects the optical axis of the objective lens system 21 toward the objective lens system 21.

[Action]

If the image forming range of the subject 5 is determined by the finder 8, the image can be captured in the same image forming range. It is preferable that the lens 1 is integrated into a camera and the lens 1 is switched by an operation.

〔Example〕

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS. 1A to 3. Although this embodiment is an electronic still camera, the same parts as those of the conventional example described with reference to FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 1A is a plan view of the electronic still camera 2 of the present embodiment, which is obtained by adding the macro deflection lens 1 to the objective lens optical system 21 described in FIG. This lens 1
Is shown in FIG. 1B. Lens 1 is a convex lens having a different radius of curvature R ₁ and R ₂ lens inner surface 1a and an outer surface 1b, functions as close-up magnifying lens. The center of curvature of each inner surface 1a and outer surface 1b is set at a different position, and if the thickness change of the lens due to the curvature is excluded, the thickness on one side is large around the optical axis and the thickness is trapezoidal toward the other side. Is gradually becoming thinner. That is, the inner surface 1a and the outer surface 1b have a main surface at the center of the optical axis having an angle difference, and have a structure in which the convex lens and the trapezoidal prism are integrated.

The refractive index of the lens 1 configured as described above becomes large where the thickness increases, and the refractive index decreases as the thickness decreases away from the lens. Therefore, the lens 1 has a function as a prism capable of deflecting light in addition to a function as a macro lens.

In FIG. 1A, light from the subject 5 is incident on the front surface 3 of the camera 2 at an angle θ (= tan ⁻¹ x / y), but passes through the lens 1 to enter the optical axis a of the optical system 21. Deflected to be parallel.

When close-up photography is performed by adding the above-described lens 1 to the optical system 21, the subject 5 is moved by the viewfinder 8 as shown in FIG.
Is determined, the subject 5 is aligned on the same straight line as the optical axis b of the optical system of the finder 8. And subject 5
Enters the lens 1 at the above angle θ, and is deflected by the lens 1 so as to be parallel to the optical axis a of the optical system 21 and form an image on the light receiving surface 26a of the CCD 26. Therefore,
Since the image formation range of the subject 5 formed on the light receiving surface 26a matches the image formation range obtained by the viewfinder 8,
No parallax occurs between the imaging range of the subject 5 determined by the finder 8 and the imaging range of the subject 5 on the light receiving surface 26a.

FIG. 2 is a perspective view of the electronic still camera 2. A macro deflection lens 1 is provided substantially at the center of the front surface 3 of the electronic still camera 2.
Alternatively, a hole 20 facing the lens 21a constituting the optical system 21 is provided, and a horizontally-long rectangular hole 6 facing the strobe light emitting unit 7 is provided next to the hole 20. Further, a hole 18 is provided in which the lens 8a constituting the optical system of the finder 8 faces outside. Hole 20
A strobe sensor 10 for detecting the amount of light emitted from the strobe and a light emitting diode 11 for blinking at the time of timer photographing and notifying the release timing are provided between the hole 18 and the hole 18, respectively. Between the hole 20 and the light emitting diode 11 and below them, there is provided a lens switching knob 9 for adding or removing the macro deflection lens 1 to or from the optical system 21.

On the upper surface 13 of the camera 2, a mode switch 12 is provided at a position close to the front surface 3 for switching between three modes of power off, single shooting mode and continuous shooting mode. Also,
Behind the upper surface 13, there are provided a shutter release button 13 that can be pressed to take a picture and a self-timer button 15 that takes a picture after a certain period of time. Between these buttons 14 and 15, an information display section 16 on which various information is displayed and a plurality of buttons 17 for operating a buzzer or other functions for calling the user various attentions. Are provided respectively.

FIG. 3 shows a cross section of a main part of the electronic still camera 2 as viewed from the front, and shows a switching mechanism of the lens 1 by the lens switching knob 9. An elongated lens support frame 42 for holding the macro deflecting lens 1 includes a circular portion 42a for holding the lens 1 and an operating pin 40 on the opposite side of this portion, and a pin 40 between the circular portion 42a and the pin 40. It is pivotally supported by a fixed fulcrum pin 39 closer to it. The circular portion 42a is provided with a flat portion 42b that comes into contact with a stopper (camera housing side) (not shown) for positioning the lens support frame 42.

The lens 1 and the support frame 42 are integrally formed of a plastic lens material.

Below the lens 1 and above the partition plate 19 in the camera 2, there is provided an elongated slide plate 37 for sliding the working pin 40 right and left in FIG.
The slide plate 37 has a protrusion 36b of a slide piece 36 described later.
And a notch 37d, into which horizontal rectangular holes 37b and 37c for a slide guide into which the fulcrum pin 39 and another fixing pin 38 are inserted, and a working pin 40 are fitted.
It has.

A slide piece 36 is provided on the lower side of the partition plate 19, and the slide piece 36 has a square hole 36a at substantially the center thereof,
In addition, a projection 36b is provided that extends through a hole (not shown) provided in a part of the partition plate 19 and extends above the partition plate 19. Then, a projection (not shown) provided integrally with the lens switching knob 9 shown in FIG. 2 is fitted into the hole 36a,
When the lens switching knob 9 is slid left and right, the slide piece 36 can slide in the directions of arrows e and e 'in FIG. 2 in accordance with the slide movement.

In the switching mechanism of the lens 1 configured as described above, by sliding the knob 9
When the slide 36 moves in the direction of the arrow e, the slide plate 37 moves in the same direction via the spring portion 37a that fits with the protrusion 36b of the slide piece 36, so that the slide plate 37 fits into the notch 37d of the slide plate 37. The operating pin 40 of the lens support frame 42 thus moved also moves. Then, the support frame 42 holding the lens 1 rotates in the direction of arrow f in FIG.
When the lens 42b comes into contact with the stopper, the lens 1 stops when the center of the optical axis of the lens 1 coincides with the optical axis a of the optical system 21. When the slide piece 36 is slid in the direction of e 'by the knob 9, the lens support frame 42 rotates in the direction of the arrow f' by performing the reverse of the above operation, and the lens 1 is removed from the optical system 21. In this way, the lens 1 can reciprocate in the camera 2 between the positions indicated by the solid line and the dashed line in FIG. 1A.

The electronic still camera 2 of the present embodiment configured as described above operates the knob 9 at the time of close-up shooting to add the macro deflecting lens 1 to the objective lens optical system 21 for photographing, so that the subject 5 viewed through the finder 8 And the photographed image obtained through the objective lens 21 can be prevented from shifting, so that photographing as seen through the viewfinder 8 can be performed.

〔The invention's effect〕

Since the present invention is configured as described above, it is possible to correct parallax generated between the optical system for photographing and the optical system of the finder during close-up shooting. Therefore, it is possible to take a picture as seen through the viewfinder. Moreover, since the configuration is a simple one in which a close-up lens having an optical axis deflection function is added to an optical system for photographing, it is possible to reduce the number of parts, cost and size of the close-up device.

[Brief description of the drawings]

1A to 3 show an embodiment according to the present invention. FIG. 1A is a plan view of an electronic still camera, and FIG.
FIG. 2 is a cross-sectional view of the macro deflection lens shown in FIG. 2, FIG. 2 is a perspective view of the electronic still camera, and FIG. FIG. 4 is a plan view of a conventional electronic still camera. In the reference numerals used in the drawings, 1... Macro-deflection lens 5... Subject 8... Finder 21... Objective lens optical system for photographing a... Optical axis of optical system 21 b. The optical axis of

Claims (1)

(57) [Claims] 1. An optical system according to claim 1, further comprising a close-up lens inserted into an objective lens system, wherein said close-up lens faces an object on an optical axis of an optical finder having an optical axis parallel to an optical axis of the objective lens system. A close-up apparatus, wherein the apparatus is integrated with a prism that deflects the optical axis of the objective lens system.