JPH05313238A - Camera - Google Patents

Abstract

PURPOSE:To detect the loading state of a film and trouble when dust, etc., are stuck between a head and the film. CONSTITUTION:The film information of a magnetic track is read by a magnetic head 13, amplified by an amplifier 21, sent to a digital converting circuit, simultaneously, to a rectifier circuit 22, and converted to an average DC voltage, inputted to one input terminal of a comparator 25. On the other hand, a signal corresponding to the feeding speed of the film, is inputted to the other input terminal of the comparator 25. The comparator 25 compares a signal voltage Vh corresponding to the output of the head 13, with a signal voltage Vf corresponding to the feeding speed of the film, so that when Vh<Vf is obtained, an LED is turned on and a warning action is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera using a film having a magnetic recording portion.

[0002]

2. Description of the Related Art Conventionally, a member using a film with a magnetic recording portion, having means for rewinding during filming, and when the film is rewound midway, information relating to the film moves integrally with the feeding of the film. U.S. Pat. No. 4,864,332 proposes a camera in which magnetic information is recorded on a recording medium, and this information is read by a magnetic head as the film is fed, or photographing information is written.

[0003]

However, in the above-mentioned conventional example, since a signal recorded by one device (camera) may be read by another device, a magnetic head for reading or writing a magnetic signal. And a standard is set between the tracks for magnetic recording on the film, and each device must be designed to comply with the standard.For example, the azimuth angle of the magnetic head of the camera or the track position may cause a shock. If there is a deviation, the problem that the recorded magnetic information cannot be read on the camera side or that the information written by this camera cannot be read by another device occurs.

Further, when dust or the like adheres to the magnetic head, a gap is created between the magnetic head and the magnetic track on the film, so that the magnetic information cannot be read correctly, and the medium on the magnetic track is sufficiently written when writing. There is a problem that the recording cannot be saturated due to incomplete recording.
Furthermore, since the film feeding speed changes depending on the type of film, the usage environment of the camera, and the usage status of the battery, the amplitude of the signal output from the magnetic head changes accordingly. It was difficult to know if is the correct magnetic head condition.

The present invention has been made to solve the above problems, and it is necessary to confirm whether the magnetic head is mounted properly in a camera using a film with a magnetic recording portion, or whether the gap between the magnetic head and the film is normal. An object of the present invention is to provide a camera capable of knowing whether or not dust or the like is attached.

[0006]

In order to achieve the above object, the camera of the present invention comprises means for detecting the film feeding speed and means for detecting the magnitude of the amplitude of the magnetic signal to be read. Each detection means is provided with a means for issuing a warning when the feeding speed and the amplitude of the magnetic signal have a predetermined relationship.

[0007]

According to the present invention, by comparing the film feeding speed with the amplitude of the magnetic signal to be read and issuing a warning when the film feeding speed and the amplitude of the magnetic signal have a predetermined relationship, the camera It has become possible to detect that the magnetic head is not in a normal state due to azimuth deviation, track deviation, dust, etc. of the magnetic head attached to the head.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 3 are views for explaining an embodiment of the present invention. In FIG. 1, 1 is a film cartridge,
2 is a film coated with a magnetic layer, 4 is perforation, 6 is a track in which information about the film is recorded as magnetic information, 7 is a roller for detecting the feeding of the film, 8 is a film which is interlocked with the roller 7 SW for turning on / off according to feeding, 9 for detecting opening / closing of the lid of a cartridge chamber (not shown), 10 fork for film feeding, 11 for gear unit for film feeding, 12 for film feeding A feeding motor, 13 is a magnetic head, 14 is a pad pressing unit, 15 is a pressing pad, and 16 is a perforation detecting photo reflector for detecting the feeding of the film.

In FIG. 2, reference numeral 21 is an amplifier for amplifying the output of the magnetic head 13, 22 is a rectifying circuit for converting the AC output of the amplifier 21 into a DC average value output (Vh), and 23 is a digital analog signal of the amplifier 21. The output of a decoding circuit for converting the signal is input to a reading circuit (not shown). Reference numeral 24 denotes an FV conversion circuit that outputs a voltage corresponding to a cycle in which the SW8 turns on / off in synchronization with the film feeding, that is, a voltage (Vf) corresponding to the film feeding speed,
Reference numeral 25 is a comparator to which the outputs of the rectifying circuit 22 and the FV converting circuit 24 are input. Reference numeral 26 is a warning circuit, and when the output of the comparator 25 becomes "0", for example, an LED is turned on to perform a warning operation.

FIG. 3 is a graph showing the relationship between the voltage Vh corresponding to the output of the head and the voltage Vf corresponding to the feeding speed of the film. Graph a shows the normal state of the head and graph b shows the relationship. The state of the head indicates, for example, a state where the off-track or the azimuth angle is increasing. The graph c is a reference, and the range below the graph c is determined to be an abnormal state and a warning is issued.

Next, detailed operation will be described. The information on the film is converted into a digital signal on the magnetic track 6 and is recorded by saturation recording. This signal is read by the magnetic head 13 at the time of feeding the film, and its output is amplified by the amplifier 21 and sent to the digital conversion circuit of the decoding circuit 23, and is also sent to the rectification circuit 22, and the rectification circuit 22 receives the input AC signal. DC average voltage (V
h) and input to one input terminal of the comparator 25. The SW8 turns on / off in synchronization with the feeding of the film, and this signal converts the frequency into voltage.
Entered in. As a result, the voltage signal Vf corresponding to the film feeding speed can be obtained. This signal is the comparator 2
5 is input to the other input terminal. The comparator 25 compares the signal voltage Vh corresponding to the output of the head 13 with the signal voltage Vf corresponding to the film feeding speed. If Vh> Vf, "1" is output and Vh <Vf If there is, "0" is output. The output is input to the warning circuit 26. The warning circuit 26 turns off the LED, for example, when the input is "1", that is, Vh> Vf, and the input is "0", that is, Vh <
When it is Vf, the LED is turned on and a warning operation is performed.

[0012]

As described above, according to the present invention, by comparing the output of the magnetic read signal and the film feeding speed, it can be confirmed that the mounting state of the magnetic head is normal, and that the gap between the magnetic head and the film is It is possible to know whether it is normal, that is, whether or not dust is attached to the head.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a schematic configuration of a main part of a camera according to an embodiment of the present invention.

FIG. 2 is an electric circuit block diagram of the camera shown in FIG.

FIG. 3 is a graph showing the relationship between the output of the head of FIG. 1 and the film feeding speed.

[Explanation of symbols]

1 film cartridge 2 film 6 magnetic track 7 roller for detecting film feeding 8 SW for interlocking with the roller 7 to turn on / off according to film feeding 10 film feeding fork 11 film feeding gear unit 12 film feeding motor 13 magnetic head 21 amplifier 22 rectifier circuit 24 FV conversion circuit 25 comparator 26 warning circuit

Claims (1)

[Claims] 1. A film having a magnetic recording portion is used,
In a camera capable of reading the magnetic signal recorded on the film by the magnetic reading means, the camera is provided with a means for detecting the feeding speed of the film, and a means for detecting the magnitude of the amplitude of the magnetic signal to be read. A camera provided with means for issuing a warning when the feeding speed and the amplitude of the magnetic signal have a predetermined relationship by the respective detecting means.