JPS62100744A - System for transmitting lens information of camera - Google Patents

Abstract

PURPOSE:To transmit precisely the information of a photographing lens to a camera body by detecting the reflected light of light emitted from a light emitting element from a pattern by a light receiving element to transmit the information of the photographing lens to the camera body. CONSTITUTION:When the photographing lens 2 is loaded to the camera body 1, a label 4 is positioned immediately in front of a transparent cover 5. A beam radiated from each light emitting diode 6 is reflected in accordance with the information of each segment of the label 4 and made incident upon a phototransistor 7 and the information is read out. The resistance of the phototransistor 7 corresponding to the segment part with a high reflection factor is low and that corresponding to the segment part with a low reflection factor is high. When these resistance values are read out as binary signals of '1' and '0', code information such as '01001010' is obtained and different kinds of information for the photographing lens 2 can be distinguished by the camera body 1. Thus, the information of the photographing lens can be precisely transmitted to the camera body.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a camera lens information transmission system for transmitting information about the photographic lens to the camera body in a camera with a detachable photographic lens.

[Prior Art] Conventionally, in this type of device, information from the photographic lens is read electrically or transmitted mechanically, and the former has the problem of erroneous transmission due to poor contact due to rust, etc. However, the latter has problems such as being mechanically complicated.

[Object of the Invention] In addition, by encoding and writing information about the photographing lens based on the difference in light reflectance in the contact portion of the photographing lens with the camera body, the photographing lens can be easily changed with only a small change on the photographing lens side. An object of the present invention is to provide a camera lens information transmission system that can reliably transmit information on a camera body.

[Summary of the Invention] The gist of the present invention to achieve the above-mentioned object is to provide a camera with a detachable photographic lens, by utilizing differences in light reflectance on the mounting surface of the photographic lens or its vicinity. When the information on the photographic lens is patterned and recorded, a light emitting element and a light receiving element are provided in the camera body, and the photographing lens is attached to the camera body, the light reflected from the pattern by the light from the light emitting element is The camera lens information transmission system is characterized in that information about the photographing lens is transmitted to the camera body by receiving light with the light receiving element.

[Embodiments of the invention] The present invention will be explained in detail based on illustrated embodiments.

FIG. 1 is a perspective view of the camera body 1 viewed from the mount side, and FIG. 2 is a front view of the interchangeable photographic lens 2 from the mount side. Coded information as shown in FIG. 3 is adhered to the mounting surface 3 of the photographic lens 2 using a label 4, for example. On the other hand, at the position of the camera body 1 facing the label 4, there is provided a transparent cover 5 made of synthetic resin having an arc shape that almost matches the shape of the label 4, and inside the transparent cover 5, as shown in FIG. A plurality of pairs of detectors each including a phototransistor 6 and a phototransistor 7 are provided in parallel. A light shielding plate 8 is interposed between the light emitting diode 6 and the phototransistor 7.

When the photographic lens 2 is attached to the camera body 1, the label 4 is located just in front of the transparent cover 5. The luminous flux emitted from each light emitting diode 6 is reflected according to the information of each segment of the label 4, enters the phototransistor 7, and the information is read. This information is read by turning on the light emitting diode 6 and sequentially detecting the output of the phototransistor 7. At this time, the segment portion of the label 4 with high reflectance corresponds to the phototransistor 7.
has little resistance, and parts with low reflectance have high resistance. If these resistance values are read as rlJ, a binary signal of "0", the camera body l can distinguish the information of different types of photographic lenses 2 as code information such as ro 1001010J as a whole. .

FIG. 6 shows another embodiment in which a plurality of segment information is read by a pair of light emitting diodes 6 and a phototransistor 7, and when the photographic lens 2 is attached to the camera body 1 while rotating, A label 4 representing information on the photographing lens 2 side is arranged so as to pass just in front of the light emitting diode 6 and the phototransistor 7. Therefore, the phototransistor 7 reads information sequentially one segment at a time.

The information about the photographic lens 2 may be written directly on the mount surface 3, or may be written on the label 4 and then glued as in the embodiment. It can be used not only for transmitting information to the photographic lens 2, but also for transmitting information to a strobe or the like.

[Effects of the Invention] As explained above, the camera lens information transmission method according to the present invention employs information encoded based on differences in light reflectance, so that modification of the photographic lens side does not require the information to be transmitted. For example, it is a simple method such as gluing it on as a small label, and by doing so, a camera lens for a system that does not transmit information such as focal length or aperture value when opened can be modified to be used in a system that does. It has the advantage of being able to automatically select an automatic exposure program.

[Brief explanation of drawings]

The drawings show an embodiment of the camera lens information transmission system according to the present invention, in which Fig. 1 is a perspective view of the camera body, Fig. 2 is a front view of the photographic lens, Fig. 3 is a front view of the label, and Fig. 4. 5 is a front view of the transparent cover, FIG. 5 is a side view of the detection section, and FIG. 6 is a front view of the detection section of another embodiment. 1 is the camera body, 2 is the photographic lens, 3 is the mount surface, 4 is the label, 5 is the transparent cover, 6 is the light emitting diode,
7 is a phototransistor.

Claims (1)

[Claims] 1. In a camera with a detachable photographic lens, information on the photographic lens is patterned and recorded on or near the mounting surface of the photographic lens by utilizing differences in light reflectance. , when a camera body is provided with a light emitting element and a light receiving element, and the photographing lens is attached to the camera body, the light receiving element receives reflected light from the pattern due to light from the light emitting element, and the photographing lens A camera lens information transmission method, characterized in that the information is transmitted to the camera body. 2. The camera lens information transmission system according to claim 1, wherein the information pattern is displayed by encoding a label. 3. The camera lens information transmission method according to claim 1, wherein the information transmission is performed after the photographic lens is attached to the camera body. 4. The camera lens information transmission method according to claim 1, wherein the information transmission is performed when the photographing lens is rotatably attached to the camera body.