Facsimile and static presentation processing – Facsimile – Picture signal generator
Reexamination Certificate
1997-01-17
2001-07-17
Grant, II, Jerome (Department: 2624)
Facsimile and static presentation processing
Facsimile
Picture signal generator
C358S474000
Reexamination Certificate
active
06262814
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a microfilm scanner which searches or retrieves a target frame from a strip-shaped microfilm, reads an image in the target frame using a line sensor, and outputs data representing the read image to a CRT or a printer. The present invention also relates a control method for this microfilm scanner.
2. Description of the Prior Art
There is a known microfilm scanner, which searches or retrieves a target frame from a strip of microfilm such as a roll film and reads an image projected from the target frame using a line sensor. There is also proposed a microfilm reader which uses the above microfilm scanner in combination with an output device such as a CRT display or a printer.
The use of the line sensor to read an image makes it easier to process the image as digital image signals, to display it onto a CRT or a liquid crystal display panel, or to output it to a printer. This also makes it easier to store data representing the read image into a memory such as a magneto-optical disk or to transfer the image data to other image processor. Therefore, the read image can be widely used.
In a microfilm formed in a band, tape, ribbon or long strip shape, such as a roll film, search or retrieval marks such as blips are generally provided or recorded within a given range of an edge side. Therefore, the given range from each edge of the film is defined as a region for search marks and an image is photographed on the remaining range between both edge-side regions. Thus photographed image constitutes a frame containing an original or document image.
When reading an image in a target frame using such a microfilm scanner, it may be appreciated that the entire area except the search-mark regions scanned with high density, that is, it will be desirable to be able to read only image signals in the image photographed region with high density for use as image data to be output. It is therefore necessary to correctly discriminate a range occupied by photographed image frames from a range occupied by search marks. In the conventional microfilm scanner, however, the operation procedure such as for discriminating therebetween is made complicated.
For example, when the image photographed on the microfilm is a negative image, the background portion in each original image is blackened and white frame region surrounds each original image. When a negative image is reversed to make it a positive image, the above mentioned white frame region turns to the blackened frame region. In this specification, such portions other than the original image region in the frame are called a black frame. On the other hand, search marks or blips are typically black spots or markers on the edge of the negative-positive reversed film, one spot or marker for each frame. Therefore, the black frames and the search marks are often confused with each other. As a result, the detection accuracy of the microfilm scanner is lowered and thereby a range including the target frame may not be detected.
SUMMARY OF THE INVENTION
The present invention has been accomplished under the circumstances as aforementioned, and a first object thereof is to provide a microfilm scanner which easily eliminates search marks on a strip of microfilm so that only a range including a target frame (image photographed range) can be scanned precisely.
Also, a second object of the present invention is to provide a control method for a microfilm scanner, in which search marks on a strip of microfilm are easily eliminated so that only a range including a target frame (image photographed range) can be scanned precisely.
The first object of the present invention is attained by the provision of a microfilm scanner having a line sensor for reading an image photographed or recorded on a frame of a strip-shaped microfilm, comprising:
(a) film-edge detecting means for receiving an output of said line sensor obtained by scanning the microfilm in the main scanning direction perpendicular to the lengthwise direction of the microfilm and for detecting a width edge of the microfilm in each main scanning line; and
(b) reading-range setting means for setting a range of an image to be read in each main scanning line by referring to the detected edge of the microfilm.
The second object of the present invention is attained by the provision of a control method for a microfilm scanner, in which an image photographed or recorded on a frame of a strip-shaped microfilm is read by a line sensor, comprising steps of:
detecting a width edge of the microfilm by using an output of the line sensor; and
setting a range of an image to be read in each main scanning line by referring to the detected edge.
If a width of the microfilm is known in advance, start and end points of the image reading range can be set by referring to the first-detected film edge in the main scanning direction of the line sensor.
Among from outputs of the line sensor, which have been used for detecting the edges of the film, only image signals contained in the image reading range are selected so that the image in the image reading range represented by the selected image signals can be used as an output image. Alternatively, the line sensor may perform two types of scanning; the one is first or preliminary scanning for detecting width edges of the film, and the other is second or real scanning.
After the image reading range is set through the preliminary scanning with low density, the second or real scanning may be performed with high density. Image signals contained in the image reading range set by preliminary scanning are selected from the entire image signals obtained by the second scanning operation. With such a operation, an image represented by the selected image signals can be read for use as an output image.
The line sensor may perform preliminary scanning for detecting a black frame of a target frame and its inclination angle, then may perform real scanning for reading the original image with high density. In such a case, the line sensor can scan the entire range (image reading range) except the search mark region by referring to the edges of the film, during the preliminarily scanning, before the black frame and its inclination angle are detected.
Referring now to
FIGS. 6 and 7
, an outline of the present invention will be described. In
FIG. 6
, there is shown a portion of a roll of microfilm
200
. In the film
200
, each of given ranges a, b from both edges
202
,
204
has been set to be a region where a search mark or blip
206
should be provided to each frame. Accordingly, an image in each frame has been photographed in a range c between the ranges a and b. The range c is thus set to be an image photographed range including an image in each frame.
Although a line sensor
208
is to read a enlarged image projected from the film
200
, it is conceptually or schematically illustrated over the film
200
in
FIG. 6
for easy understanding of the present invention. The line sensor
208
is arranged in a direction substantially perpendicular to a length-wise direction of the film
200
to relatively move in the length-wise direction of the film
200
(a direction indicated by an arrow in FIG.
6
).
The line sensor
208
scans or reads an image in a main scanning direction, for example, from the lower side to the upper side in FIG.
6
. Outputs of the line sensor
208
are supplied to film-edge detecting means
210
in which the first edge
202
of the film
200
is detected. After detecting the first edge
202
, reading-range setting means
212
determines coordinates of an end point of the range a, where the blip
206
has been provided to each frame, and coordinates of an end point of the image photographed range c. In other words, the reading-range setting means
212
determines coordinates of the start and end points of the image photographed range (image reading range) c.
The outputs of the line sensor
208
are also supplied to image reading means
214
. In the image reading means
214
, image signals in the reading rang
Fuji Photo Film Co. , Ltd.
Grant II Jerome
Sughrue Mion Zinn Macpeak & Seas, PLLC
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