JPS604172Y2 - Warning device inside the viewfinder - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an in-finder warning device for an eye reflex camera with an exchangeable focusing glass.

Interchangeable focusing glass - When replacing the focusing glass on an eye reflex camera to accommodate an interchangeable lens, most single-lens reflex cameras use a method that measures the light after it passes through the focusing glass, so an exposure meter is required. may not work properly due to the influence of the transparent focusing glass.

In other words, there are various types of focusing glasses, such as those with a matte surface, those with completely transparent surfaces, and those with square scales engraved on the transparent surface. Even with matte surfaces, there are different types of matte surfaces, such as those with coarse grain size and those with fine grains.

For this reason, in single-lens reflex cameras that determine the exposure conditions by receiving the subject light that has passed through the focusing glass, the amount of light that enters the light receiving element changes depending on what kind of focusing glass is attached to the camera. .

On the other hand, the amount of light irradiated onto the film surface is, of course, unrelated to the focusing glass.

Therefore, when trying to determine exposure using a light-receiving element placed in the finder optical path, when a focusing glass with a specific light transmittance among various types of focusing glasses is attached as standard, the light-receiving element is The included photometric circuitry is adapted to indicate proper exposure conditions.

For this reason, when a focusing glass other than the above-mentioned standard focusing glass is attached, appropriate exposure will not be instructed.

Moreover, not only does it not work correctly, but it also instructs the camera to use incorrect exposure as if it were the correct exposure, resulting in the camera being photographed at an incorrect exposure.

This invention improves this and provides a warning device in the viewfinder that can automatically indicate that the exposure meter is not working accurately when the focus glass is replaced, without having to operate a lever on the camera side. This is what I am trying to do.

An embodiment of this invention will be described below with reference to the drawings.

FIG. 1 schematically shows the construction of a finder system, in which a pentaprism 1 is disposed at the top of the negative side of the camera body, and an eyepiece 2 is further disposed along this prism.

A frame body 3 is attached to the lower part of the pentaprism 1, and this frame body 3
A focusing glass support 4 is rotatably attached to the lens.

That is, a support fitting 6 is fixed to one side of the frame 3 with a screw 5, and one end of the focus glass support 4 is rotatably locked to the lower part of the support fitting 6.

In addition, an elastic support piece 7 is fixed to the other side of the frame 3 with screws 8, and a protrusion 9 on the left side of the focus glass support 4 is inserted into a through hole provided in the elastic support piece 7, so that the elastic support piece 7 can be elastically fixed. engage.

The focus glass 10 is placed on the focus glass support 4,
It is fixed so that there is no movement between it and the frame body 3.

Further, a transparent plate 11 having a display section for exposure alignment is installed between the focusing glass 10 and the pentaprism 1.

In the figure, 12 is a light receiving element, and 13 is a rotatably provided reflecting mirror.

In this invention, as particularly shown in FIG. 2, a warning display section 14 is provided on the focusing glass 10 to warn that the exposure meter is not working correctly.

As shown in FIG. 2, a transparent plate 1 is placed below the pentaprism 1.
1, and this transparent plate 11 is provided with a display section 15 for exposure adjustment.

The display section 14 of the focusing glass 10 is formed by, for example, applying color to the transparent plate 11 at a position corresponding to the display section 15.

Therefore, when the photographer looks through the viewfinder, the colored display section 14 appears within the viewfinder's field of view, overlapping the display section 15 for exposure adjustment, as shown in FIG. It can make you realize that you are not working.

In this case, if the warning display section 14 were not provided, the photographer would only look at the display section 15 for exposure adjustment, which would lead to the photographer determining that the exposure was appropriate and taking a wrong picture.

As described above, this invention is a relatively simple means that can automatically warn of inappropriate exposure when the focusing glass is replaced.

In the above embodiment, the display section 15 for exposure adjustment is provided on the transparent plate 11, but the display section 15 alone may be made to appear and disappear within the field of view of the finder without using the transparent plate 11.

Further, in the above embodiment, the warning display section 14 is colored, but this section can also be made opaque or formed with letters, symbols, etc.

Further, as shown in FIG. 4, when the display section 15 for exposure adjustment is outside the viewfinder screen, the focus glass 10
It is only necessary to form a protrusion 16 and provide a warning display in this part.

Further, as shown in FIG. 5, when the focusing glass itself has a frame, a part of the frame may be made to protrude to form a display section for warning.

As described above, this invention provides an in-finder warning device that can automatically and reliably display, with a relatively simple configuration, that the exposure meter is not working accurately when the focusing glass is replaced. can do.

Note that this invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications without changing the gist.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of an embodiment of this invention, Fig. 2 is a simplified perspective view for explaining the relationship between the transparent plate and the focusing glass in the same embodiment, and Figs. 3 and 4. Each figure is a plan view showing the field of view within the finder to explain the operation of this invention, and FIG. 5 is a perspective view showing different examples of focusing glasses. 1... Pentaprism, 2... Eyepiece, 3... Frame, 4... Zent glass support, 5... Screw, 6... Support metal fittings, 7... Elastic support pieces, 8... Screws, 9
... Protrusion, 10 ... Zent glass, 11
...Transparent plate, 12... Light receiving element, 13
...Reflector, 14... Warning display section,
15...Display section for exposure adjustment.

Claims (1)

[Scope of utility model registration request] It has an exchangeable focusing glass and a light receiving element that measures the subject light that passes through the focusing glass and reaches the eyepiece.
In a single-lens reflex camera in which an exposure display section is disposed in the finder optical path and operates in response to the output from a photometric circuit including this light-receiving element, the above-mentioned focusing glasses have a transmittance other than the standard light transmittance. An in-finder warning device, characterized in that the focus glass is provided with a warning display section, which is made of a colored or opaque portion, at a position corresponding to the display section, and covers the exposure display section.