JPH05150322A - Magnetic reproducing device of camera - Google Patents

Abstract

PURPOSE:To prevent an unnecessary signal from being mixed owing to variation of a film in magnetic reproduction equipping a magnetic head with plural tracks and selecting a reproduction signal according to the large/small decision making of the tracks. CONSTITUTION:The magnetic head H is provided with the adjacent tracks and a selecting means 16 which obtains the signal of one optional track or a combination of adjacent optional tracks is provded. A control circuit 8 such as a microcomputer which controls various operations of the camera decids the larger output selected by the selecting means 16 or the larger output of the combination and outputs it as the reproduction signal. Namely, reproduction is performed by using many tracks, so a reproduction error is prevented without providing a tracking mechanism for film variation and even magnetic record of a photograh film which is inferior in SN ratio can excellently be reproduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic reproducing apparatus for a camera equipped with a magnetic head for reproducing information from a magnetic storage section provided in a film.

[0002]

2. Description of the Related Art In recent years, a film having a magnetic track (magnetic storage portion) has been used, and information such as the date of the year, shutter time, aperture value, etc. can be written on this magnetic track by a magnetic head, or when necessary. In accordance with U.S. Pat. No. 4,864,332, there is proposed a camera capable of reading the information or reading information such as the film sensitivity and the number of specified film frames recorded in advance.

[0003]

However, in this type of camera, the film feed is not stable due to load fluctuations due to the power source battery, the number of film frames, etc., and the film is fed vertically (vertically). I was shaken by.
Further, the case where the position of the magnetic track tilts to the left and right with respect to the film feeding direction due to the individual difference of the camera and the individual difference of the film has largely occurred in the camera system which has not conventionally considered magnetic recording.

Therefore, the film shakes in the vertical direction with respect to the feeding direction, the relative position of the magnetic head and the film (magnetic track) shifts during magnetic reproduction, and it is possible to reproduce accurately on the written magnetic track. Since this is not possible, that is, the reproduction of tracks is shifted, unnecessary signals in the magnetic layer outside the written range are mixed to form a reproduction error. Therefore, in order to deal with this, it is necessary to make the magnetic head have a complicated structure that follows the end face of the film without being fixed to the camera body.

Further, as a magnetic recording / reproducing system for a magnetic card, there is a system in which writing is performed widely during recording and only the center is reproduced during reproduction to reduce the influence of off-track. The magnetic density of the magnetic layer for forming the magnetic track is lowered in order to maintain the magnetic field. If the width of the magnetic track is narrow, the reproduction signal is small and the S / N ratio is deteriorated, which may cause reproduction error. Due to the large size, it was difficult to adopt this method for a camera.

The object of the present invention is to solve the above problems,
Without providing a complicated mechanism for causing the magnetic head to follow film fluctuations, it is possible to prevent unnecessary signals from being mixed with each other and to cause a reproduction error, and to suppress the S / N recorded on the photographic film. It is an object of the present invention to provide a magnetic reproducing device for a camera which can reproduce even bad magnetic information in a good condition.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a magnetic head is provided with a plurality of adjacent tracks, and a selecting means for obtaining a signal of an arbitrary track or a combined signal of arbitrary adjacent tracks is provided. And a control means for discriminating between the larger output selected by the means or the larger combination output and outputting this as a reproduction signal.
Further, the magnetic head is provided with a plurality of adjacent tracks, and a selecting means for obtaining a signal of an arbitrary track or a combined signal of adjacent adjacent tracks, and decoding the output selected by the selecting means. Decoding means, error detecting means for judging whether or not each decoded signal is correctly reproduced, and output means for selecting and outputting a reproduced signal judged to be correct by the error detecting means. It is provided.

[0008]

In the magnetic reproduction, the fluctuation of the film is absorbed by providing the magnetic head with a plurality of tracks, and selecting at least one of the outputs of the plurality of tracks as the reproduction signal, and absorbing it. Playback is performed by as many tracks as possible in order to increase / N.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view showing an internal structure of a main part of a camera which is a first embodiment of the present invention.

In the figure, reference numeral 1 is a photoreflector for detecting a perforation P of a film F, which will be described later, and generating a signal for indexing one frame of the film F and a signal for the timing of writing information. 2 is a film feeding motor arranged in the spool, 3 is a gear train for decelerating and switching between winding and rewinding, 4 is a rewinding fork, C is a film cartridge, and F is a belt. -The above-mentioned film provided with a magnetic track (magnetic storage section) T on the side, P is the above-mentioned perforation, H is the writing of information on the magnetic track T on the film F, or the information from here. Is a magnetic head for reading. Reference numeral 5 denotes a pad that presses the film F against the magnetic head H, and has a concave portion at the central portion for increasing the adhesion of the head gap between the film F and the magnetic head H.

FIG. 2 is a circuit block diagram of a main part of the camera.

In the figure, 7 is a power supply battery for the camera, and 8
Is a control circuit such as a microcomputer for controlling various operations of the camera, 9 is a release switch for starting photography, and 10 is the film feeding mode for winding and rewinding the film F. A film feed circuit for driving the image pickup device 2; a pulse detection circuit 11 for converting a perforation signal from the photoreflector 1 into a corresponding signal for the control circuit 8; and 12 for supplying various information to the magnetic track T of the film F. A magnetic recording circuit for driving the magnetic head H for recording, a film F through the magnetic head H.
Magnetic reproducing circuit for reading magnetic information from the magnetic track T of
Reference numeral 14 is an AE that performs known photometry, distance measurement, and shutter control.
An AF / SH circuit, 15 is a liquid crystal display for displaying the number of frames of film F, and 16 is means for selecting an effective track from among three tracks (magnetic reproducing section) 1 to 3 equipped with a magnetic head H. ..

FIG. 3 is a flow chart showing the operation of the control circuit 8.
It is a chart, and will be described below according to this. [Step 1] Whether or not the film cartridge C is loaded is determined from the state of the film presence / absence switch (not shown), and the process proceeds to step 2 by determining that it is loaded. [Step 2] The film feeding motor 2 is normally rotated through the film feeding circuit 10 to start winding the film F. [Step 3] The magnetic reproducing circuit 13 and the magnetic head H start reproducing magnetic information recorded on the film.
At this point, the reproduction of the information is not started, and thereafter, the tracks for reproducing the information are selected by steps 4 to 10. [Step 4] Adjacent tracks 1 to 3 will be described later.
Of the magnetic head H including the track 1 and the track 2
Is selected by the selection means 16 to obtain the selected output. [Step 5] The amplitude of the reproduction signal of the magnetic information read by the tracks 1 and 2 selected in step 4 is stored as "A1". [Step 6] Here, the selection means 16 selects tracks 2 and 3 so as to obtain the selected output. [Step 7] The amplitude of the reproduction signal of the magnetic information read by the tracks 2 and 3 selected in step 6 is stored as "A2". [Step 8] The size of “A1” and “A2” stored in steps 5 and 7 is discriminated, and if “A1” is larger, the process proceeds to step 9. If "A2" is larger, the process proceeds to step 10. [Step 9] Selection is made by the selection means 16 so that the reproduction is thereafter performed by the track 1 and the track 2, and the process proceeds to step 11. [Step 10] The selection unit 16 selects the reproduction so that the reproduction is performed later on the tracks 2 and 3, and the process proceeds to step 11.

Here, FIGS. 4 and 5 show an example of a magnetic head H having a plurality of adjacent tracks.

In FIG. 5, C ₀₁ , C ₀₂ , C ₀₃ , and C ₀₄ are core portions, and g is a gap for reproducing a magnetic signal. L _1, L _2, L ₃ is wound around the core of the C _04, C _03, C ₀₂ respectively, a coil for taking out a change in the magnetic flux flowing in each of the core portions as an electric signal. These form tracks T ₁ , T ₂ , and T ₃ .

FIG. 4 is a circuit example more specifically showing the magnetic head H, the selecting means 16 and the first stage amplifier of the magnetic reproducing circuit 13. SWA and SAB are switches constituting the selecting means 16 and control circuits respectively. The signals A and B of 8 are controlled as shown in FIG.

FIG. 7 shows a state when information is reproduced by the selected track.

Tracks 1 to 3 (L ₁ + L of the magnetic head H)
₂ + L ₃ ) is widely written, and tracks 1 and 2 (L ₁ + L ₂₎ are offset when upwardly written so as not to pick up a noise signal from the unwritten upper and lower areas due to off-track during playback. ) Is selected by the selecting means 16 and is offset downward, the track 1,
Select 3 (L ₁ + L ₃ ). [Step 11] Magnetic Head H and Magnetic Reproducing Circuit 13
Is driven to reproduce information such as film information or a specified number of frames stored in advance on the magnetic track T of the film F being wound. Then, these pieces of information are set in the camera. Alternatively, the information written by the camera, for example, the date, the user name, is reproduced. [Step 12] The perforation signal from the photo reflector 1 is detected through the pulse detection circuit 11,
It is determined whether or not the number of photographed frames has reached the first frame, and if not, the process stays in step 12, and when it reaches, the process proceeds to step 13. [Step 13] The driving of the film feeding motor 2 is stopped through the film feeding circuit 10 and the winding of the film F is stopped. [Step 14] Magnetic Head H and Magnetic Reproducing Circuit 13
To stop the playback of information. [Step 15] Since only magnetic writing is performed after the end of photographing, "track 1 + track 2 + track 3" is selected by the selection means 16 so that the track width becomes wider. [Step 16] It is determined whether or not the release switch 9 is turned on, and if it is turned on, the process proceeds to step 17. [Step 17] Subject brightness information is obtained by the AE / AF / SH circuit 14 to determine the shutter opening / closing conditions. [Step 18] Here, the AE / AF / SH circuit 14
The subject distance information is obtained to drive the lens barrel to focus on the subject. [Step 19] The AE / AF / SH circuit 14 is driven to perform shutter opening / closing control, that is, exposure control based on the shutter opening / closing conditions obtained in step 11 above. [Step 20] The film feeding motor 2 is rotated in the forward direction through the film feeding circuit 10 to start winding the photographing frame. [Step 21] Magnetic Head H and Magnetic Recording Circuit 13
Is driven to write information such as the shooting date, shutter time, aperture value and the like to the shooting frame during film feeding by the tracks 1 to 3. [Step 22] It is determined whether or not one frame of perforation signal is input from the photo reflector 1 via the pulse detection circuit 11, and the process proceeds to step 23 by determining that it is input. [Step 23] The number of frames (frame) displayed on the liquid crystal display 15 is counted up. [Step 24] The driving of the film feeding motor 2 is stopped through the film feeding circuit 10 and the winding of the film F is stopped. [Step 25] Here, the specified number of frames information taken into the means for detecting the last frame of the film (not shown) is compared with the current number of frames. If not completed, the process returns to step 16. [Step 26] The film feeding motor 2 is reversely rotated through the film feeding circuit 10 to rewind the film F. [Step 27] Whether or not the film cartridge C has been removed from the camera is determined from the state of the film presence / absence switch (not shown), and the process returns to step 1 by determining that it has been removed.

In this embodiment, as shown in FIG. 6, the case for selecting only the track 2 is shown. This is not directly related to off-track, but the data on the magnetic track T of the film is not shown. -Because it becomes effective when there is a loss of data. For off-track, track 1
It is preferable that only the track 3 is selected. As described above, the signal becomes small in one of the tracks 1 and 3, but even if the offset is large, an effect of cutting unrelated signals can be expected.

FIG. 8 is a diagram showing a circuit configuration of a main part in the second embodiment of the present invention.

This is the flow shown in FIG. 3 of the first embodiment.
This is a circuit portion for performing the operations in steps 3 to 10 in the chart.

Reference numerals 71 and 72 are adders, and an amplifier Amp
The adder 71 outputs the sum of 1 and the output of the amplifier Amp2,
The sum of the outputs of the amplifier Amp2 and the amplifier Amp3 is the adder 7
2 is output. Reference numerals 73 and 74 are peak detectors for holding the amplitude of the reproduced signal output, and hold the magnitudes of the reproduced signals of the adder 71 and the adder 72, respectively.
Then, the switch 76 is switched, and the output of the larger reproduction signal is sent to the magnetic reproduction circuit.

By performing the processing as described above, it is possible to select a track in real time, unlike FIG.

FIG. 9 shows a third embodiment of the present invention in which FIG. 8 is further improved.
FIG. 9 is a diagram showing an embodiment of the present invention, in which the same parts as those in FIG.

The outputs of the adders 71 and 72 are converted into "0" and "1" by the binary circuits 81 and 82, respectively, and are stored in the registers 83 and 84, for example, 1 byte of 8 bits. The contents of the registers 83 and 84 are sent in parallel to the parity check circuits 85 and 86, where it is judged whether the data is correctly reproduced by the 7-bit data and the 1-bit parity bit. If they are correct, the AND gate 87, The data of 8 bits of the registers 83 and 84 is output to the control circuit 8 and the like through 88. If both are correct, the contents are the same, so the sum may be taken by the oaget 89.

According to each of the above-mentioned embodiments, the magnetic head having a plurality of adjacent tracks is provided, and the selection means for obtaining a combined signal of any adjacent tracks adjacent to each other, and the reproduction signal of the selected output is large. Combination or decoration
Since it was equipped with a control means that discriminates the signal evaluated to be correct by the camera, due to the unstable film feeding of the camera,
It became possible to obtain a good reproduction signal without the need for a tracking mechanism for the off-tracking of the magnetic track and the magnetic head.

Further, since the off-track direction can be detected, a wide range of tracks can be selected according to it, so that the reproduction signal is large and the S / N ratio is good, and the magnetic recording of the photographic film having a poor S / N ratio is good. Playback is possible.

(Modification) In this embodiment, a magnetic head having three tracks is used, but a magnetic head having more tracks may be used. Further, in the present embodiment, the reproduction signal is selected according to the level magnitude, but it is also conceivable that error detection of each signal is performed and the reproduction signal is selected accordingly.

[0029]

As described above, according to the present invention,
In addition to providing multiple adjacent tracks on the magnetic head,
Selection means for obtaining a signal of an arbitrary track or a combined signal of adjacent adjacent tracks, a larger output selected by the selecting means, or an output of a larger combination is discriminated, and this is determined. A selection means for outputting a reproduction signal, and a plurality of adjacent tracks on the magnetic head, and a selection means for obtaining a signal of an arbitrary track or a combined signal of arbitrary adjacent tracks; Decoding means for decoding the output selected by the means, error detecting means for judging whether or not each decoded signal is reproduced correctly, reproduction for judging the error by the error detecting means An output means for selecting and outputting a signal is provided, and the fluctuation of the film during magnetic reproduction is smaller than the judgment of the output of the plurality of tracks by providing the magnetic head with a plurality of tracks. Kutomo Select one with absorbed by the reproduction signal which is to perform the playback by as many tracks in order to increase the S / N.
Therefore, it is possible to prevent unnecessary signals from being mixed with each other and to cause a reproduction error without providing a complicated mechanism for causing the magnetic head to follow film fluctuations, and to suppress the S / S recorded on the photographic film. Even magnetic information having a poor N can be reproduced well.

[Brief description of drawings]

FIG. 1 is a perspective view showing an internal configuration of a main part of a camera according to a first embodiment of the present invention.

FIG. 2 is an electric block diagram of a main part of the camera shown in FIG.

FIG. 3 is a flowchart showing the operation of the control circuit of FIG.

FIG. 4 is a circuit diagram showing a configuration of a magnetic head and a selection unit according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of a magnetic head according to the first embodiment of the present invention.

FIG. 6 is a diagram showing an example of track selection by the selection means of FIG.

FIG. 7 is a diagram showing how tracks are selected by the camera according to the first embodiment of the present invention.

FIG. 8 is a circuit diagram showing a configuration of a main part of a camera according to a second embodiment of the present invention.

FIG. 9 is a circuit diagram showing a configuration of a main part of a camera according to a third embodiment of the present invention.

[Explanation of sign]

2 film feeding motor 8 control circuit 13 magnetic reproduction circuit 16 selecting means 71,72 adder 73,74 peak detector 76 switch 81,82 binary circuit 83,84 register 85,86 parity check circuit 87, 88 AND GATE 89 OAGART F Film with magnetic track H Magnetic head T ₁ , T ₂ , T ₃ track

Claims (2)

[Claims] 1. A magnetic reproducing apparatus for a camera having a magnetic head for reproducing information from a magnetic storage unit provided in a film, wherein the magnetic head is provided with a plurality of adjacent tracks, and a signal of an arbitrary track, or Is a selection means for obtaining a combined signal of adjacent arbitrary tracks, a larger output selected by the selecting means or a larger combination output, and a control means for outputting this as a reproduction signal. A magnetic reproducing device for a camera, characterized by being provided with. 2. A magnetic reproducing apparatus for a camera having a magnetic head for reproducing information from a magnetic storage unit provided in a film, wherein the magnetic head is provided with a plurality of adjacent tracks, and a signal of an arbitrary track, or Is a selection means for obtaining a combined signal of adjacent arbitrary tracks, a decoding means for decoding the output selected by the selection means, and a judgment as to whether or not each decoded signal is correctly reproduced. A magnetic reproducing apparatus for a camera, comprising: an error detecting means for performing the error detection; and an output means for selecting and outputting a reproduction signal determined to be correct by the error detecting means.