Photography – With data recording – Magnetically on film or film cassette
Reexamination Certificate
2001-06-07
2002-04-16
Gray, David M. (Department: 2851)
Photography
With data recording
Magnetically on film or film cassette
C396S390000
Reexamination Certificate
active
06374058
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a magnetic recording and regenerating unit for photographic film and a camera, and more particularly to a magnetic recording and regenerating unit which records magnetic information in a magnetic recording layer on the photographic film and regenerates the magnetic information recorded in the magnetic recording layer, and a camera which the magnetic recording and regenerating unit applies to.
2. Description of Related Art
Advanced photographic film has been proposed in which one side of silver salt film is coated with a magnetic layer (U.S. Pat. No. 5,130,745). A film cartridge which contains the film and a camera which uses the film cartridge for photographing have also been proposed, and they are standardized worldwide.
As shown in FIGS.
32
(
a
) and (
b
), an advanced cartridge roll film
100
is constructed in such a manner that the film
103
which is wound around a spool
102
is stored in a cartridge case
101
, which is substantially cylindrical. A light-shielding lid
104
is provided at one end of the cartridge case
101
. The film
103
is completely stored in the cartridge case
101
when the roll film
100
has not loaded in the camera or after the roll film
100
has been taken out from the camera, and the light-shielding lid
104
protects the film
103
from external light.
A data disk
105
is provided at a side end of the cartridge case
101
, and the data disk
105
rotates in association with the spool
102
. A bar code is printed on the exterior face of the data disk
105
, and the bar code indicates the type and sensitivity of the film
103
, the number of frames to be exposed, etc.
Apertures which are shaped like a circle, a square, a cross and a semicircle are formed on the other side end of the cartridge case
101
. A sectorial white plate (not shown) is provided at the back of these apertures, and the white plate rotates in association with the spool
102
. One of the circle, the square, the cross and the semicircle is displayed in white according to a position where the white plate stops. The display of the circle in white indicates that the film in the cartridge case
101
is unexposed; the display of the square in white indicates that the film has already been developed; the display of the cross indicates that the film has already been exposed but undeveloped; and the display of the semicircle in white indicates that the film has some unexposed frames remaining. The display in white is called VEI (visual exposure index), and the index is seen with eyes from the outside to confirm the status of the film used.
The film
103
is constructed in such a way that a surface
103
F of the film base is coated with a silver salt photosensitive layer and the reverse side
103
R of the film is coated with a magnetic recording layer. Multiple perforations
121
are formed at the edge of the film
103
to specify the range of each frame
120
. The photographing information such as the type of a light source for photographing and a focal length, and the information such as the title of the photograph used as a message to a user can be magnetically recorded in magnetic record areas
124
,
125
at the upper and lower end of each frame.
When the cartridge film is loaded in the camera, an optical reading mechanism in the camera reads information indicated with the bar code on the data disk
105
, and detects the position of the white plate, thereby automatically recognizing the information relating to the film and the used status of the film. In the case of the cartridge film with no exposed film or with some unexposed frame remaining, the light-shielding lid
104
is opened and the spool
102
is rotated in a predetermined direction, so that the film
103
can feed to the first unexposed frame.
After all frames on the film
103
are exposed, a rewind mechanism in the camera takes up the film
103
into the cartridge case
101
, and closes the light-shielding lid
104
. Further, the white plate, which is fixed on the spool
102
, is stopped in a manner to face the cross-shaped aperture, thereby displaying the cross in white to indicate that the film has already been exposed.
If the film is forcibly rewound during photographing with some unexposed frames remaining, the rewind mechanism in the camera takes up the film
103
into the cartridge case
101
, and closes the light-shielding lid
104
. Further, the white plate, which is fixed on the spool
102
, is stopped in a manner to face the semicircular aperture, thereby displaying the semicircle in white to indicate that the film has some unexposed frames remaining.
On the other hand, if the loaded cartridge contains the film on which all frames are exposed or developed, the process is executed to prevent the automatic feeding or the like because photographing is impossible.
According to the above-described camera, the film may be forcibly rewound in a state where there are some unexposed frames remaining on the film, and the film cartridge may be taken out of the camera (hereinafter this film cartridge, which contains the film being partially exposed, is referred to as “a partial cartridge”). When the partial cartridge, which contains the photographic film with one or more of exposed frames and one or more of unexposed frames, is loaded again in the camera, the information in the magnetic recording layer is read via a magnetic head in the camera, and the film feeds to an area with no magnetic information recorded. Thereby, the photographing can be performed from an unexposed frame.
The magnetic recording layer formed on the photographic film has a low magnetic density. Moreover, the base thereof is harder than a conventional magnetic tape, and thus a head touch easily becomes unstable. Hence, a special magnetic head only for reading is provided in which the number of turns of the coil is increased so as to exactly read the information.
In a magnetic head (a regenerating head) in a conventional magnetic regenerating unit for a camera, which regenerates the magnetic information from the magnetic recording layer on the photographic film, the number of turns of the coil wound around the core is approximately 1500. That is because S/N is lowered if the number of turns is small, and thus the magnetic information is difficult to read.
On the other hand, a magnetic head (a recording head) which records the magnetic information in the magnetic recording layer on the photographic film cannot be driven if the number of turns is large. For this reason, the number of turns of the coil is usually between 80 and 100. Thus, a regenerating head and a recording head are provided independently of one another, or a recording coil and a regenerating coil are wound around a core.
FIG. 33
illustrates an example of a conventional magnetic head driver. The magnetic head driver
150
is driven by electricity supplied from a power source V
B
, and a lithium battery, which is used as a power source for the camera as a whole, is used as the power source V
B
. A magnetic head
152
is driven by bridge-connected switching transistors
154
,
155
,
156
,
157
, and ON/OFF of which are controlled by control transistors
160
,
161
. The control transistors
160
,
161
are turned on and off, respectively, by switching signals (a clock pulse and a data pulse) which oppositely switch the first port P
1
and the second port P
2
onto a high (H) level and a low (L) level.
After the start of the magnetic recording, if the port P
1
becomes the L level and the port P
2
becomes the H level according to the clock pulse and the data pulse from a microcomputer, the control transistor
160
is turned off and the control transistor
161
is turned on. Thereby, the switching transistors
154
,
156
are turned off, and the switching transistors
155
,
157
are turned on. Thus, the recording current I
H
flows from the right to the left in the drawing through a coil
152
a
, which composes the magnetic head
152
. Thereby, the magnetic head
152
generates a magn
Funaki Akihiko
Ishiguro Minoru
Sasaki Wataru
Fuji Photo Film Co., LTD
Gray David M.
Sughrue & Mion, PLLC
LandOfFree
Magnetic recording and regenerating unit for photographic... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Magnetic recording and regenerating unit for photographic..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic recording and regenerating unit for photographic... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2916515