JPS5962838A - Focusing device in fixed focus camera - Google Patents

Abstract

PURPOSE:To attain a fine picture in general photographing as well as strobe photographing by setting a parallel plane glass, which is placed between a photographing lens and a film, to a frame interlocking with a contact lever for strobe switching in a fixed focus camera provided with a strobe. CONSTITUTION:The device is so constituted that the strobe use is switched by contacting with a contact lever 4 operated by a knob 6, and a parallel plane glass 3 having a prescribed thickness is set to a frame 5 interlocking with this contact lever 4. When the strobe is use, this glass 3 is removed from the space between a photographing lens 1 and the film, and the light incident from the lens 1 does not pass through the glass (in case of short-distance photographing). In case of general photographing which does not use a strobe 2, the glass 3 is placed orthogonally to the optical axis between the lens 1 and the film, and consequently, the light incident from the lens passes through the glass 3, and this glass 3 is moved in accordance with movement following to the frame 5 interlocking with the operation of the strobe. The glass 3 is inserted or removed between the lens 1 and the film in accordance with long or short distance to focus the camera in both cases, and photograhing is performed accurately; and since the glass 3 is operated easily while interlocking with switching between strobe use and strobe disuse, photographing is performed easily without requiring operation and discrimination at all, and the camera is focused accurately, and consequently, pictures in the very good state are attained.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a focus adjustment device that is linked to the use and non-use of a strobe in a fixed focus camera manufactured by the present invention.

In other words, in a popular camera equipped with a strobe,
Instead of using a conventional complicated structure in which the movement of the lens is adjusted using a helicoid or the like according to the far and near distance of the subject, the photographing lens remains fixed, which is an extremely simple structure. It is possible to easily match the focus position during general photography and when using a strobe, which is always close-up photography, without any need for judgment or operation effort, and to obtain sufficient sharpness for practical use. The depth of field is widened, and the quality of the photograph is therefore very good.

To explain the present invention with reference to the drawings, Fig. 3 shows a perspective view of the entire camera, and Fig. 2 shows the internal mechanism of the camera equipped with a system strobe (2). The use of the flash is configured to be switched by contacting the lever (4), and the contact lever (4)
A parallel plane glass (3) of a predetermined thickness and a fairly thin thickness is installed on the frame (5) which is interlocked with the frame (5).
When using a strobe, the glass plate (3) escapes from between the photographic lens (1) and the film, and the light that enters from the lens does not pass through the glass (for close-up photography). For general shooting without using Shins (1
) and the film, the glass (3) is located perpendicular to the optical axis, so the light entering from the lens passes through the glass (3), and the parallel plane glass (3) is linked to the operation of the strobe. It is configured to follow the movement of the frame (5).

In addition, the camera lens (1) of the present invention is fixed in advance, and the focal point is set to be the film position. The image ray (a) is refracted by the lens (1), and the image ray (b) from a distance of 4 m is refracted by the lens (1). ) When it is refracted by υ, its focus becomes old and its position shifts by υ.

As shown in Figure 1 (B), when the glass (3) is used to transmit the image, the focal point of the image beam (b) from the 4m distance 1t moves by . This is how the material and thickness of the glass (3) are set and configured. This allows the focal position of the image at 41 (general photography) and the focal position at z, 5m (stroboscopic photography) to be set. By attaching and detaching the glass, it is possible to match the shooting lens and film at X while keeping them fixed.

Note that H in the figure indicates the optical axis. As a general rule, when shooting with a strobe, the distance is far from the 1F arrival point of the strobe, so when you turn on the contact lever (4) with the knob (6), the glass (3) simultaneously moves to the lens ( 1) In the state in which the object is separated from the film and in the state in which it is removed, the focus object is as good as the film is present, and an extremely in-focus photograph can be obtained.

For general photography (4 to 7+ equipment is appropriate),
As a general rule, if you do not use the strobe (2), you will operate the contact lever (4) so that it is not in use, but this operation will cause the lens (1) to move as shown in Figure 1 (B). By interposing the glass (3) between the film and the film, the focal point (b) in that state aligns with the position where the film is, and therefore the above-mentioned strobe photography (2, 5f)
The focal point position in the case of the focal point (set at the i position) and the focal point in the case of general photography (set at the 4-- position) with the glass interposed Therefore, good photos can be obtained in both general photography and strobe photography.

As described above, in the present invention, the photographing lens (1) and the strobe (
2) in a fixed focus camera comprising a lens (1);
A parallel plane glass plate (3) of a predetermined thickness located between the lens and the film is attached to the frame linked to the strobe switching contact lens (-), so that the lens and film can be adjusted depending on the distance between the lens and the film. By moving the parallel plane glass plate in and out between the two, you can focus on either side and take accurate pictures.The operation of the glass plate (3) is linked to switching between using and not using the strobe. Because it is easy to do, it is easy for the user to change colors depending on the shooting conditions, without requiring any operations or judgments that require multiple steering and high skill. It is an excellent invention because it can be used to take pictures, is accurately focused, and therefore produces pictures in very good condition, and has an extremely simple structure.

[Brief explanation of drawings]

(3) and (B) in Figure 1: Explanation of the relationship between the P lens, the parallel glass plate, the projected light beam, and the focal point. Figures 1 and 2 are perspective views of the inside of the camera, and Figure 3 shows the remainder of the camera. , showing a look around. (1) Lens, (2) Strobe, (3) Parallel plane glass, (4) Fist/contact lever, (5) Frame, (6)
...Tsu size, (Fl, (F')...Focus. O 2nd mouth 312th

Claims (1)

[Claims] In a fixed-focus camera equipped with a strobe, a parallel flat glass of a predetermined thickness located between the photographic lens and the film is attached to a frame linked to a contact lever for switching the strobe, and when the strobe is used, the glass is 7. The focus adjustment device according to claim 7, wherein the focusing device is configured to be installed so as to escape from between the lens and the film and to be located between the lens and the film when the strobe is not in use.