JPS6158022B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a single-lens reflex camera, in particular, a single-lens reflex camera, in which light from a photographic information carrier is introduced into the pentaprism through a sub-prism provided in the pentaprism, thereby capturing images within the viewfinder. This invention relates to a single-lens reflex camera that displays photographic information along with the field of view.

For single-lens reflex cameras that can display shooting information such as shutter speed and aperture value in the viewfinder, an information display means such as a meter is placed under the bottom of the penta roof prism so that the light from this can be directly directed to the pentameter. There are those that are introduced into the roof prism, and those that are introduced into the penta roof prism from the bottom of the penta roof prism via a sub-prism. A conventional method for fixing a subprism to a pentaprism is to fix the subprism to a front non-reflective surface or a front reflective surface of the pentaprism.
It was fixed on the pentadaha surface. First, in the case where the sub-prism is attached to the front non-reflective surface, the sub-prism part protrudes in front of the camera, which poses a problem in terms of form. In addition, in the case of attaching a sub-prism to the front reflecting surface or roof surface, since these surfaces reflect the light flux from the photographing field, it is necessary to avoid the reflective surface, which reduces the degree of freedom in design. There was.

The object of the present invention is to provide a compact and simple structure capable of displaying photographic information within the viewfinder field of view.
Therefore, it is an object of the present invention to provide a viewfinder for a single-lens reflex camera that is easy to manufacture and inexpensive.

In order to achieve this object, in the single-lens reflex camera of the present invention, a sub-prism is attached to a portion of the exit surface of the pentaprism that does not block the photographing field of view light. In a single-lens reflex camera, the exit surface of the pentaprism has a relatively large margin, so that the above-mentioned drawbacks do not occur.

Further, in the single-lens reflex camera of the present invention, a groove is provided in a portion of the exit surface of the pentaprism that does not block the photographic field of view light, and one end of the sub-prism is inserted into this groove. For this reason,
It becomes possible to align the photographic field of view light within a plane perpendicular to the exit surface of the pentaprism. That is,
It becomes possible to bring the photographing field of view and the photographing information close to each other.

The present invention will be explained in detail below with reference to the drawings.

1 and 2 are schematic illustrations of a first embodiment of the invention. Reference numeral 1 designates a penta roof prism, in which light rays from the subject image focused on a focusing glass 5 pass through a condenser lens 6 and then enter the prism 1 through a lower entrance surface 11, a roof surface 12, and a front reflective surface 1.
3 and exits from the rear exit surface 14 and is directed toward the eyepiece lens 4. A groove 15 is provided to guide display information light into the pentagonal roof prism, and its upper surface 15a is a transmitting surface. Further, this groove portion is provided outside a portion A through which photographing field light passes, as shown in FIG.

Reference numeral 2 denotes a small sub-prism, which in the embodiment shown in this figure has an entrance-transmitting surface 21, an exit-transmitting surface 22 (which coincide in this diagram), and reflecting surfaces 23 and 24. The sub-prism 2 is arranged such that the emission and transmission surface 22 faces the groove upper surface 15a with a small distance therebetween. 31 and 32 are information display means, and in the embodiment shown in this figure, 31 is an aperture scale;
2 is a meter pointer. Information display means 31, 32
The display information light L enters the entrance/transmission surface 21 of the sub-prism, is reflected by the reflection surfaces 23 and 24, and exits from the exit/transmission surface 22. The light L emitted from the exit transmission surface enters the pentagonal roof prism through the groove upper surface 15a, and the left and right roof surfaces 12 and the front reflective surface 1.
After being reflected by the prism 1, it is directed toward the lower part of the rear exit surface 14 of the prism 1, from which it exits and is directed toward the eyepiece lens 4. The information display means 31 and 32 display the photographing field F of the viewfinder as shown in
Display information 31' at a predetermined position below the
32'. Also, information display means 3
The information display means 31, 3 is set so that the diopter for 1, 32 approximately matches the diopter of the viewfinder photographing field.
2 and a sub-prism are arranged, there is no need for an auxiliary lens to match the diopter. The reflective surfaces 23 and 24 of the sub-prism 2 of this embodiment may utilize total reflection, or may have a reflective film adhered thereto.

Since this embodiment is constructed as described above, the sub-prism 2 does not form any strange protrusion on the exterior of the camera, and the bottom of the groove 15 is separated from the focusing plate 5 as shown in FIG. Because it is located near the luminous flux,
As shown in FIG. 3, information can be displayed near the field of view F', making it easier to see the information. Furthermore, when there is a light-receiving element P for photometry on the upper part of the exit surface of the pentaprism as shown in Fig. 1, by applying black paint to the bottom and lower surface of the groove, it is possible to directly connect the light-receiving element P from the focusing plate. This has effects such as being able to remove incident light.

FIG. 4 is a schematic diagram of a second embodiment of the invention.

1 is a penta roof prism, and 4 is an eyepiece. The arrangement of each of the above elements is substantially the same as that of the finder shown in FIGS. 1 and 2. In the embodiment shown in this figure, a light emitting diode is used as the information display means,
It is located at the bottom of the eyepiece. sub prism 2
1 is a light emitting diode 3 placed at the bottom of the eyepiece
In order to direct the display information light L to the groove upper surface 15a of the penta roof prism, it has a rhombic shape, and furthermore, the exit/transmission surface 22 of this sub-prism and the groove 15a of the penta roof prism are joined to each other. By joining the penta-roof prism and the sub-prism, the two prisms become one, which has the advantage of being convenient to handle. In the embodiment shown in this figure, the information 3 of the light emitting diode is displayed as display information 3' at a predetermined position below the photographing field of view F, as shown in FIG.

FIG. 6 is a schematic diagram of a third embodiment of the invention.

1 is a pentaprism, 2 is a sub-prism, 3 is an information display means, and 4 is an eyepiece. The arrangement of each of the above elements is substantially the same as that of the finder shown in FIGS. 1 and 2.

In the embodiment shown in this figure, the aperture scale of the lens barrel is displayed on the viewfinder. 3 is the aperture scale of the lens barrel, 7 is the auxiliary lens, 81, 82,
9 is an auxiliary mirror. The display information light L from the aperture scale 3 is reflected by the auxiliary mirrors 81 and 82, and then focused on the 3a by the auxiliary lens 7, and further reflected by the auxiliary mirror 9 onto the X-ray transmitting surface 2 of the sub-prism 2.
1. Thereafter, it follows the same optical path as explained in FIG. 1 and is displayed as display information 3' at a predetermined position below the photographic field of view F' as shown in FIG. In the embodiment shown in this figure, changes such as replacing the auxiliary mirrors 81, 82, and 9 with prisms and changing the position of the auxiliary lens 7 can be made as necessary.

As described above, the single-lens reflex camera of the present invention has a simple configuration in which a part of the exit surface of the pentagonal roof prism is processed into a groove shape and a small sub-prism is arranged, and therefore the structure is simple. It has the advantages of being easily miniaturized, easy to manufacture, low manufacturing cost, and having a degree of freedom in arranging the information display means, which is advantageous in terms of camera design.

[Brief explanation of the drawing]

1 and 2 show the first embodiment of the present invention, FIG. 3 shows the viewfinder field of view of the first embodiment, and FIGS. 4 and 5 show the second embodiment of the invention. The figures shown in FIG. 6 and FIG. 7 are diagrams showing a third embodiment of the present invention. 1 is a penta roof prism, 2 is a sub prism,
33 is photographing information, and 24 is a groove.

Claims (1)

[Claims] 1. In a single-lens reflex camera in which light from a photographic information body is introduced into the pentaprism through a sub-prism provided on the exit surface side of the pentaprism, and the photographic information body is displayed together with the photographic field of view in the viewfinder. , a groove portion with the roof surface side as a transmitting surface is formed at a position where the exit surface of the pentaprism does not block the photographing field light, and the sub-prism has an upper surface at one end as an exit surface, the other end as an entrance surface, and a light incident from the entrance surface. The sub-prism has an intermediate reflective surface that directs the light toward the exit surface, and the exit surface on the upper surface of one end of the sub-prism is inserted and arranged to face the transmission surface of the groove, and the light is introduced from the entrance surface on the other end of the sub-prism. The light beam from the photographic information carrier is reflected by an intermediate reflecting surface, and then introduced into the pentaprism from the exit surface through the transmission surface of the groove, and then sequentially passed through the roof surface, front reflection surface, and exit surface of the pentaprism. A single-lens reflex camera is characterized in that the light is emitted from the eyepiece side.