JPS6239414B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improving the image quality of a camera that records auxiliary images such as data near the main image. It is suitable for special cameras that capture auxiliary images such as.

In a special imaging device such as a fundus camera, it is common to record various data near the location where a main image such as a fundus image is taken and use it for later examination. However, data imprinting cameras are widely used in intermediate-level cameras and single-lens reflex cameras.
In these cameras, it is customary to imprint data into the main image, and since the main image forming light beam is bright, deterioration in exposure due to the data imprinting light beam does not pose much of a problem.

On the other hand, for example, in medical photography, where there is not enough light, the data imprinting light flux may deteriorate the image quality, and since any area within the main image is particularly important, data is imprinted outside the main image. It is customary. However, if the auxiliary image is placed too far away from the main image, it will not only be difficult to see, but will also take up a lot of storage space or require a large amount of photographic film, which is wasteful.

However, when the two images are close to each other, the image forming light flux of each projection optical system may enter the position on the film surface that should be occupied by the other image after the final optical element of the projection optical system is generated. arise. This is undesirable because it results in so-called fogging for the other party's image and reduces the contrast of the image. Furthermore, in the case where the main image is scaled, the auxiliary image is adversely affected by the main image forming light flux when the scale is varied.

If the internal space of the camera was large, it would be possible to separate the two image-forming light beams sufficiently, but there is generally no such room, especially when attaching and detaching a ready-made camera body to the mirror body that houses the camera system. For special cameras of this type, there is even less leeway because the diameter of the mount is fixed.

An object of the present invention is to photograph an auxiliary image close to the main image and to prevent the image quality of both images from deteriorating.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a fundus camera will be described below with reference to the drawings.

Figure 1 is a side view, and Figure 2 is a view from above, where E is the eye to be examined, A is the mirror body that houses the photographing system and illumination system, and B is the film chamber, which is used for single-lens reflex cameras. Uses the body of a Rex camera. M is a bayonet mount, which has the function of connecting mirror body A and film chamber B. Furthermore, number 1 is an observation illumination light source, 2a
and 2b are condenser lenses, 3 is a light source for photography,
4 is a light shielding plate with an annular opening, 5 is an optical path bending mirror,
6a and 6b are relay lenses, 7 is a perforated mirror with a circular aperture, 8 is an objective lens, and the above members constitute an illumination system.

Next is the focusing lens. Reference numeral 10 denotes an imaging lens which has a function of re-forming the image formed by the objective lens 9. 11 is shutter, 12 is film. Reference numeral 13 denotes a mask, which has an opening 13a that defines the area where the main image is taken and a small opening 13b that defines the area where the auxiliary image is taken, as shown in FIG. street main image 12a
An auxiliary image 12b such as data is separated and imprinted in the vicinity thereof. The above 8 to 13 members constitute the imaging system. Further, 14 is an attachment lens which can be attached and detached behind the imaging lens 10.
It has the effect of enlarging the image without moving the imaging position in the optical axis direction.

Next, 15 is a quick-turn mirror, 16 is an optical path bending mirror, and 17 is an eyepiece lens, and these members constitute a finder. E ₀ indicates the examiner's eyes.

Furthermore, a data display plate 21 is inserted into and removed from the outside of the housing (not shown), and the patient's name, number, date, etc. are displayed on its surface. 22 is a small flash light source, which has the function of illuminating the plate 21. 23a and 23b
are optical path bending mirrors, and 24 is a projection lens, which constitute a projection system for the auxiliary image. Reference numeral 25 denotes a rectangular light-shielding cylinder made of an opaque material, through which the projection optical path of the auxiliary image can pass, so that the image-forming light flux forms an image of the displayed object in the area defined by the small opening 13b of the mask. Form. Further, this light shielding tube 25 is provided at a position where it does not block the main image forming optical path of the photographing system.
As shown in FIGS. 5 and 6, the corner 15a of the quick return mirror 15 is cut out to the extent that the viewfinder observation image is not vignetted, allowing the light-shielding tube 25 to approach the optical axis of the photographing system. ing. Since this light-shielding tube 25 is provided within the film chamber B, it remains within the film chamber when the mount B is released and the film chamber B is separated from the mirror body A. 27 is a light shielding wall. In the above arrangement, the optical functions of the photographing system and the illumination system are well known, so a detailed explanation will be omitted.In short, when the light source 1 is turned on, the light beam passing through the illumination optical path passes through the objective lens 8. It emits and illuminates the fundus of the eye. The light beam scattered and reflected by the fundus is formed into an image by the objective lens 8, and then reflected by the quick return mirror 15 by the action of the focusing lens and the imaging lens 10, forming an aerial image and looking into the eyepiece lens 17. Observed by the examiner.

When focusing and field of view setting are completed, a release operation is performed for detection, whereby the observation light source 1 is turned off, the quick return mirror 15 is moved out of the optical path, and the shutter is opened and the photographing light source 3 emits light. The fundus of the eye is illuminated with this emitted light, and the ocularly reflected light exposes the film 12, but at the same time the photographing light source 3 emits light, the flash light source 22 for illuminating the data display plate also emits light, so that the plate 21 is emitted. The light beam is sequentially reflected by the mirrors 23a and 23b, subjected to an imaging effect by the projection lens 24, and then passed through the light-shielding tube 2.
5 and is imaged on a film 12. Since the exit end of the light-shielding tube is very close to the shutter and the entrance end is close to the projection lens, the data display plate 21
The emitted light flux does not enter the main image aperture 13a of the mask, and the main image forming light flux does not enter the small aperture 13b of the mask. Therefore,
Both light beams are sufficiently separated, and clear images can be obtained in both images without fogging or the like.

According to the present invention described above, there is an effect that the main image and the auxiliary image can be brought close to each other, and therefore, even if the auxiliary image is enlarged, it remains within the conventional range, so that data etc. can be easily read. Furthermore, the corner of the optical path selection mirror is cut out so that the light flux restriction means extending in the optical axis direction passes through the corner of the optical path selection mirror provided at the intersection of the photographing optical path and the observation optical path. The new space required for the setup can be kept small, and an off-the-shelf camera body can be used.

[Brief explanation of the drawing]

FIG. 1 is an optical cross-sectional view of the embodiment, and FIG. 2 is a plan view thereof. FIG. 3 is a plan view of the mask. FIG. 4 is a plan view of the film, and FIG. 5 is a perspective view of the camera body. FIG. 6 is a perspective view of the main optical system. In the figure, A is a mirror body, B is a film chamber, 8 is an objective lens, 10 is an imaging lens, 12 is a film, 13
is a mask, 15 is a quick return mirror, 21
is a data display plate, 24 is a projection lens, 25
is a light-shielding tube.

Claims (1)

[Claims] 1. An optical path selection mirror is provided at the intersection of the photographing optical path and the observation optical path in front of the image plane, and an auxiliary image regulated by the second aperture is placed on the image plane near the main image regulated by the first aperture. In a multi-image photographing device having a built-in independent imaging optical system for imprinting, a light flux forming a main image is incident on the second aperture, and a light flux forming an auxiliary image is incident on the first aperture. The light flux regulating means is provided with a light flux regulating means extending in the optical axis direction from the vicinity of the image plane toward the object side, and the light flux regulating means is arranged such that the light flux regulating means passes through a corner of the optical path selection mirror. A multiple image photographing device characterized in that the optical path selection mirror is a mirror with a notched corner.