Abstract: A magnetic recording and regenerating unit for photographic film and a camera, which feed photographic film coated with a magnetic recording layer, records magnetic information in the magnetic recording layer, and regenerates magnetic information from the magnetic recording layer. In the magnetic recording and regenerating unit for a camera, the number of turns of a coil wound around a core included in a magnetic head is small. Thus, one magnetic head is able to record and regenerate magnetic information. The number of turns of the coil is determined so as to output a regenerated waveform which does not enable reading of the magnetic information but permits determination of whether any magnetic information is recorded or not. Whether any magnetic information is recorded or not is determined based on the output voltage from a smoothing circuit, a peak hold circuit, etc. which receive signals output from the magnetic head via an amplifier.

Abstract: A magnetic recording and Regenerating unit for photographic film and a camera, which feed photographic film coated with a magnetic recording layer, records magnetic information in the magnetic recording layer, and regenerates magnetic information from the magnetic recording layer. In the magnetic recording and regenerating unit for a camera, the number of turns of a coil wound around a core included in a magnetic head is small. Thus, one magnetic head is able to record and regenerate magnetic information. The number of turns of the coil is determined so as to output a regenerated waveform which does not enable reading of the magnetic information but permits determination of whether any magnetic information is recorded or not. Whether any magnetic information is recorded or not is determined based on the output voltage from a smoothing circuit, a peak hold circuit, etc. which receive signals output from the magnetic head via an amplifier.

Abstract: To use a zoom lens mechanism in visible light, a switch is turned off. By force of a spring, a cam pin of a correction lens is contacted with a first edge of a cam groove which is formed to have a shape which corrects a focal inadequacy resulting from a movement of a variable magnification lens in visible light. Accordingly, the movement of the correction lens is controlled by the first edge. To use the zoom lens mechanism in near infrared light, the switch is turned on. By magnetic force of an electromagnet, the cam pin is contacted with a second edge of the cam groove which is formed to have a shape which corrects the focal inadequacy resulting from the movement of the variable magnification lens in near infrared light. Accordingly, the movement of the correction lens is controlled by the second edge.