Facsimile and static presentation processing – Facsimile – Picture signal generator
Reexamination Certificate
2000-02-22
2004-06-22
Coles, Edward (Department: 2622)
Facsimile and static presentation processing
Facsimile
Picture signal generator
C358S487000, C358S509000, C358S512000, C358S533000, C358S519000, C382S112000, C382S274000, C382S275000, C250S208100
Reexamination Certificate
active
06753984
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention The present invention relates to an image reading apparatus adapted to a film scanner or the like arranged to read an original such as a developed photographic film.
2. Description of Related Art
Known image reading apparatuses include film image reading apparatuses (hereinafter referred to as film scanners) which are arranged to read images recorded on transparent originals such as developed photographic films. Generally, a film scanner is arranged as follows. A transparent original, such as a microfilm or a photographic film (hereinafter referred to as film), is illuminated from behind the film by an illumination optical system. Then, transmission light from the film is imaged by projecting the light through a projection optical system on an image forming plane of a photoelectric conversion element. An image thus formed is photoelectrically converted by the photoelectric conversion element. Image information recorded on the film is thus electrically converted.
Some of known film scanners are arranged to improve the quality of image data by taking in the image information recorded on the film and by carrying out various processes according to the characteristic of the light source of an illumination optical system which is used for illuminating the film.
For example, a known film scanner is arranged to detect dust or the like sticking to an illumination optical system, a light projection optical system or the surface of the film and to correct an adverse effect of such dust or the like.
FIGS.
8
(A) and
8
(B) schematically show the adverse effect of dust or the like on image data and an image data output. FIG.
8
(A) shows a case where the object to be processed is a reversal film. FIG.
8
(B) shows another case where the object to be processed is a negative film.
In either case where the object to be processed is a reversal film or a negative film as shown in FIG.
8
(A) or
8
(B), when the film scanner reads recorded image information from the film by converting the image information into an image signal, i.e., image data, the dust or the like sticking to the film appears in the form of black spots.
As a result, in the case of the reversal film as shown in FIG.
8
(A), if the image data obtained by the film scanner is processed, including a gamma correction, etc., and is outputted as it is for printing or the like, the adverse effect of the dust or the like appears as the black spots.
In a case where the object to be processed is a negative film as shown in FIG.
8
(B), the image data obtained by the film scanner is converted from a negative image into a positive image by carrying out a subtracting operation on the image data read out at its full level. In that case, the adverse effect of dust or the like appears on an image output as white luminescent spots.
To solve this problem, a film scanner has been developed, in respect of the transmission characteristic of the film for infrared light, to detect only such an image area that image-deteriorating dust or the like exists, through infrared light passing through the film, and to correct the image data read out from the film on the basis of information on the image area found to have the dust or the like existing there (hereinafter referred to as dust information).
FIG. 9
is a perspective view showing the essential parts of the above-stated film scanner
800
.
FIG. 10
shows in outline the arrangement of the film scanner
800
.
FIG. 11
is a block diagram showing the internal circuit arrangement of the film scanner
800
shown in FIG.
9
.
FIG. 12
is a flow chart showing control over the actions of the entirety of the film scanner
800
shown in FIG.
9
.
Referring to
FIGS. 9 and 10
, a film carriage
801
is used as an original-placing board. A film
802
which has been developed is fixed in place on the film carriage
801
. A lamp
803
is arranged to be a visible and infrared light source and has a wide range of light-emitting characteristics including both a visible light wavelength region and an infrared wavelength region.
The film scanner
800
further includes a mirror
804
, an image forming lens
805
and a line sensor
806
which is composed of a CCD or the like. The light emitted from the lamp
803
passes through the film
802
and is reflected by the mirror
804
to be imaged on the line sensor
806
by the lens
805
. The line sensor
806
has a light receiving area composed of three light receiving parts including a red (R) light receiving part, a green (G) light receiving part and a blue (B) light receiving part. The line sensor
806
is thus arranged to be sensitive to red, green and blue light wavelengths and to be also sensitive to infrared light at least in part at the red (R), green (G) and blue (B) light receiving parts.
A motor
807
is arranged to move the film carriage
801
in the directions of scanning as indicated by arrows in
FIGS. 9 and 10
. A carriage sensor
808
is arranged to detect the position of the film carriage
801
. A dotted line
809
indicates an optical axis leading from the lamp
803
to the line sensor
806
.
An infrared-light cut filter
810
a is arranged to cut off infrared light. A visible-light cut filter
810
b is arranged to cut off visible light. Hereinafter, these filters together will be sometimes referred to as the filter
810
.
A filter motor
811
is arranged to move the filter
810
(filters
810
a
and
810
b
). The infrared-light cut filter
810
a
and the visible-light cut filter
810
b
can be set selectively at a position on the optical axis
809
by changing use of them from one over to the other.
The film scanner
800
is provided with a control circuit
812
(a film scanner control circuit), a lens holder
813
, a film scanner armoring case
814
, an input/output terminal
815
, a density sensor
816
for detecting the density of the film
802
, and a filter sensor
817
for detecting the position of the filter
810
.
The lamp
803
, the line sensor
806
, the motor
807
, the carriage sensor
808
, the filter motor
811
, the density sensor
816
, the filter sensor
817
and the input/output terminal
815
are electrically connected respectively to the control circuit
812
.
As shown in
FIG. 11
, the control circuit
812
is composed of a carriage sensor control circuit
812
a
, a density sensor control circuit
812
b
, a filter sensor control circuit
812
c
, a motor control circuit
812
d
, a filter motor control circuit
812
e
, an image information processing circuit
812
f
, a lamp control circuit
812
g
, a line sensor control circuit
812
h
, a film density detecting circuit
812
i, a motor driving speed deciding circuit
812
j
and an image information storing circuit
812
k.
The film scanner
800
which is arranged as described above operates as shown in
FIG. 12
which is a flow chart. The operation is described as follows.
Step S
901
: When a command to perform a film reading action is inputted to the control circuit
812
from outside through the input/output terminal
815
, the carriage sensor control circuit
812
a
detects the position of the film carriage
801
through the carriage sensor
808
. The result of detection is sent to the motor control circuit
812
d
. Then, the motor control circuit
812
d
drives the motor
807
to bring the film carriage
801
to a predetermined standby position.
Step S
902
: The filter sensor control circuit
812
c
detects the position of the filter
810
through the filter sensor
817
. Information on the result of detection is transmitted to the filter motor control circuit
812
e
. In accordance with this information, the filter motor control circuit
812
e
drives the filter motor
811
to set the infrared-light cut filter
810
a
on the optical axis
809
. The infrared-light cut filter
810
a
is moved onto the optical axis
809
accordingly.
Step S
903
: The film density detecting circuit
812
i
detects the density of the film
802
through the density sensor
816
.
Step S
904
: A motor driving speed is decided on the basis of density in
Canon Kabushiki Kaisha
Coles Edward
Robin Blecker & Daley
Safaipour Houshang
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