Photography – With data recording – Magnetically on film or film cassette
Reexamination Certificate
1996-02-09
2001-02-27
Mathews, Alan A. (Department: 2851)
Photography
With data recording
Magnetically on film or film cassette
C396S311000, C360S001000
Reexamination Certificate
active
06195512
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a camera adapted for films provided with magnetic storage portions and, in particular, to an improvement of information writing to the magnetic storage portion.
2. Related Background Art
Conventionally, U.S. Pat. No. 4,977,419 discloses a color negative film including a virtually transparent magnetic layer on a base surface of the film, and a camera having a magnetic head for magnetically recording information in the film or for reading the information recorded in the film. It also discloses to provide on an outside edge of the exposed face of the film a plurality of recording tracks in which the camera records information magnetically. This increases the amount of information to be recorded for individual frames by means of increasing the number of recording tracks.
Disclosed as the information recordable by the camera is photographing information such as the date of photographing, time, the type of illumination light source used upon photographing, pseudo zoom information, exposing time, diaphragm values or the like.
Alternatively, U.S. Pat. No. 4,878,075 discloses that a filmstrip is previously provided with film information written therein such as film sensitivity and film regulated frame number, and that a camera reads this information before exposure while it re-writes this information upon taking up the film after completion of exposure to record various types of information upon photographing.
To read film information previously written in a magnetic layer on a base side of the film or to write photographing information in the magnetic layer in cooperation with an exposing operation by using a magnetic head disposed in a camera, the film is required to be transported with the magnetic head being joined to the above mentioned magnetic layer. With this respect, typical cameras are so structured that a film is pinched by spring operation between the magnetic head disposed on the base side of the film and a pad disposed at a position opposing to said magnetic head on the emulsion-applied surface of the film. Accordingly, flaws or pressure marks (sensitizing due to pressure) are caused on sliding portions to the magnetic head because of the pressure required for pinching. As a result, reading of the film information and writing of the photographing data by the camera are made only at the peripheries of frames out of the frames of the film.
FIGS. 6 and 7
are views for use describing the above.
FIG. 6
is a view illustrating operation of magnetic recording on the film. In
FIG. 6
, F represents a film including a magnetic film (hereinafter, simply referred to as a film), F
1
and F
2
represent exposed frames, F
3
represents an unexposed frame and P represents a perforation. T
0
represents a film information track previously magnetically recorded in the film F, in which film information such as an ISO sensitivity of the film is recorded. A reference numeral
101
represents a magnetic head of a camera. The magnetic head comprises a first magnetic track forming unit
102
and a second magnetic track forming unit
103
. T
1
and T
2
represent first and second photographing information tracks, respectively, for individual frames recorded by the first and the second track forming units
102
and
103
in place of the film information in the film information track T
0
(overwriting using saturation recording) before one frame of the film is transported in a direction depicted by an arrow A.
FIG. 7
is a vertical sectional view of a camera having the above mentioned magnetic head
101
. A reference numeral
111
represents a camera body provided with a well-known aperture opening
111
a
, a pair of upper and lower outer rails
111
b
,
111
b
, and a pair of upper and lower inner rails
111
c
,
111
c
. A reference numeral
112
represents a platen abutted to the outer rail
111
b
. The frame F travels through or stopped for exposure at a space (tunnel) defined by the outer rail
111
b
, the inner rail
111
c
and the platen
112
.
The magnetic head
101
is secured to the platen
112
through a mounting plate
104
attached thereto and a vis
105
. The first and the second track forming arrangements
102
and
103
are located at a position sliding with the film F from a notch
112
a
of the platen
112
. In addition, the track forming arrangements
102
and
103
are laid out at a position outside the frame (depicted by C in the figure) by a photographing lens L. A reference numeral
113
represents a pad of an elastic material. The pad is secured to a receiving member
114
a
of a lever
114
. The lever
114
comprises elongated bores
114
b
and
114
c
. Pins
115
and
116
are inserted into the elongated bores
114
b
and
114
c
, respectively. The pins
115
and
116
are fixed to the camera body
111
. In addition, the lever
114
is forced rightward in the figure by a spring
117
. The spring force of the spring
117
and the pad
113
forces the traveling film F continuously to the first and second track forming arrangements
102
and
103
of the magnetic head
101
. (In
FIG. 7
, illustrated is a condition where the first and the second track forming arrangements are before forced.)
In this event, an alternating current adapted to a signal to be recorded flows through the first and the second track forming arrangements
102
and
103
to conduct magnetic recording. A magnetic field H generated in the track forming arrangements
102
and
103
are given by H∝T×A, where T represents the number of windings of a coil of the track forming arrangement while A represents a current value flowing through the coil. The magnetic field H to be required depends on the coercively of a medium subjected to the magnetic recording (the magnetic storage layer of the film F in this specification). A recording energy (i.e., the magnetic field generated at the track forming arrangement; the number of windings of the coil is involved in the direct current resistance, so that to increase H∝T×A corresponds to a power increase with respect to the device) applied by the device (the camera in this specification) to each track forming arrangement is normally constant. In view of reducing the energy for the device, the smaller recording energy is preferable as long as the coercive force of the medium can be withdrawn.
However, the above mentioned prior art has a disadvantage that the magnetic recording may be incomplete in the photographing information track (corresponding to T
1
in
FIG. 6
) at the transversal end of the film. This is because the film end is curled in the direction away from the magnetic head
101
as depicted by FC in FIG.
7
. Contact between the track forming arrangements
102
,
103
and the film F is maintained by the spring
117
and the pad
113
. However, the curling force is slightly larger than the spring force and the pad
113
is insufficient for forcing the film. As a result, a small gap (depicted by S in
FIG. 7
) is generated at the position of the track forming arrangement
102
close to the film end. This spacing loss is mainly responsible for the incomplete magnetic recording.
In addition, as shown in right-hand portion of
FIG. 7
, the above mentioned problem may be solved by means of attaching the magnetic head
101
to the platen
112
inclined by an angle &thgr; to the direction along the curling of the film, which is still not a complete solution to the above problem.
SUMMARY OF THE INVENTION
According to one aspect, the present invention is a camera adapted for films provided with magnetic storage portions or a magnetic recording apparatus for the camera of the type described comprising first information writing means for writing information in a first area of a magnetic storage portion of the film; and second information writing means for writing information in a second area of the magnetic storage portion, the second area being outside the first area of the first information writing means, in a transverse direction the second information writing mean
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Mathews Alan A.
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