JPS6125379A - Picture reader - Google Patents

Abstract

PURPOSE:To make the titled reader small in size and to keep high resolution by providing a reduced projection optical system, an image rotating optical member and a magnifying projection optical system to an optical path from a micro film to a linear image sensor and forming the picked-up picture information to an image sensor. CONSTITUTION:Picture information A retrieved to a lighting position 2 receives lighting by a light source 3 from the rear face of film, the picture information frame transmission light of the lighting light is incident to a magnification projection lens 4 and a prism 5 as an image rotation optical member and the image A1 is formed to a photodetecting plane range 7 of the linear image sensor 6 with magnification. A sensor subscanning moving drive mechanism is activated based on a read start signal for the sensor 6, which is subject to subscanning moving drive in a prescribed speed in the lengthwise direction, that is, an orthogonal direction Y-Y to the main scanning direction X-X. When the sensor 6 reaches the movement end position, the sensor 6 is reciprocated and restores to the upside position being a range 7 at the first position. A magnified image A1 of the frame A formed in the range 7 is scanned from one side to the other side and a time serial electric signal of read information is outputted from the sensor 6.

Description

[Detailed description of the invention] B. Purpose of the invention [Industrial application field] The present invention relates to an image reading device.

More specifically, a one-dimensional image sensor such as a CCD array is used as an image reading means, and image information taken on a microfilm is imaged on the light-receiving surface range of the sensor by an enlarged projection optical system including an optical member for image rotation. The present invention relates to an image reading device that scans and reads the formed image information using the above one-dimensional image sensor.

[Conventional technology]

In recent years, microfilms have been used in a wide variety of applications because they allow a large amount of information to be recorded at high density in a very small space. Information includes literature, patent publications, savings tables,
Documents such as drawings, catalogs, and newspapers are reduced and recorded on microscopic or film.

Normally, when a piece of information consists of multiple pages, the images of each page are individually imprinted on successive frames of film. In order to utilize microfilm that records this large amount of information, it is necessary to have a complete method and device for correctly reproducing the desired information.

The image reading device using the above-mentioned one-dimensional image sensor is one such device, and is in practical use. Figure 2 is a very schematic diagram of the optical system. A represents individual image information frames that are photographed and recorded sequentially along the length of the film surface. 2 is an image information frame illumination position, and a required image information frame A to be read and processed in the film 1 is located at this illumination position 2 by an automatic search mechanism (not shown) or by manual search.

The image information frame A searched at the illumination position 2 is illuminated by a light source 3 from the back side of the film, and the image information frame transmitted light of the illumination light is transmitted to an enlarged projection lens 4, and then to an optical member for image rotation. The 0 image information frame is incident on the prism 5 and is enlarged to form an image A on the light receiving surface area 7 of the -dimensional image sensor 6. Only shown. o-0 indicates the optical axis of the optical system.

The one-dimensional image sensor 6 is always on standby at the upper side of the light-receiving surface area 7 or at the solid line water position slightly outside it as a home position, and has a main scanning function in the longitudinal direction x-x. Based on the reading start signal, a sensor sub-scanning movement drive mechanism (not shown) is operated, so that the sensor 6 is moved along its longitudinal direction, that is, in the main scanning direction x or in the direction perpendicular to the main scanning direction Y.
-Y, the sensor 6 is driven to move in the sub-scanning direction at a predetermined speed (in the direction of arrow a), and when the sensor 6 reaches a predetermined end-point position of the sub-scanning movement, the sensor 6 is ID-driven and returned to its initial home position. The movement locus plane of the sensor light-receiving section defined by the main scanning length region and the sub-scanning movement length region of the sensor 6 is the light-receiving surface range 7 of the sensor 6 .

Then, the enlarged image A of the image information frame A formed on the light-receiving surface area 7 is sequentially main-scanned and sub-scanned from one side to the other side by the -dimensional image sensor 6 to form an image. Photoelectric reading of information is done.

The sensor 6 outputs time-series electric pixel signals of the read image information. The output signal is input to an image reproducing device (not shown) by wire or wirelessly, and an image corresponding to the read image information is reproduced by a CRT display, a laser beam printer, or the like.

In addition to roll microfilm, microfilm l is
It may also be microfiche film, microstrip film, etc.

The prism 5 as an optical member for image rotation optically changes the direction of the image A1 of the image information frame A formed through the enlarged projection lens 4 with respect to the light receiving surface range 7 of the sensor 6. For example, it is used for 90' conversion, 180° modification, etc., and can be rotated freely around the optical axis 0-O by a rotation operation mechanism (not shown). FIG. 3 is an optical path diagram thereof, in which Aa is an incident image and Ab is an exit image.
When the output image Ab is rotated by 0", the attitude of the output image Ab is changed by 180 degrees clockwise or counterclockwise with respect to the initial attitude. For example, when it is rotated by 180 degrees, the attitude is changed by 360 degrees.8
FIG. 4 shows another example of a prism, the function of which is the same as that of FIG.

That is, there are two types of microfilm I: one in which individual image information A is photographed and recorded in a vertical orientation, and the other in which the individual image information A is photographed and recorded in a horizontal orientation. 6(a) and 6(b) are partial plan views of the former and latter types of roll microfilm or microstrip film, respectively, and FIGS. FIG. 3 is a plan view of a portion of the former and latter types of fish films. FIG. 2 shows a state in which the image information A of the film 1 is photographed and recorded in a vertical orientation, and the image is formed into an image A+ in an image orientation that fits entirely within the light-receiving surface range 7 of the sensor 6. There is. In this case, the film 1 used is image information A.
If it is of the type that is photographed and recorded horizontally, the image information A is imaged onto the light-receiving surface area 7 of the sensor 6 through the magnifying projection lens 4 and the prism 5, as shown in FIG. is an image in a horizontal orientation with respect to the light-receiving surface area 7.

For this reason, the main scanning and sub-scanning reading by the image forming AI sensor 6 is performed with one side of the formed image A1 as the sky and the other side as the ground. etc., the reproduced image is oriented sideways and is very difficult to see, and the main scanning direction dimension W of the imaged image A1 in the horizontal orientation becomes large compared to the main scanning length dimension of the sensor 6, and the orientation of the imaged image A becomes large. The sides are outside the light-receiving surface range 7 of the sensor 6, and the outside portions α and α are not read, resulting in a reproduced image that is missing the top and bottom sides.

Therefore, in such a case, the prism 5 is rotated by 45 degrees clockwise or counterclockwise from the rotation angle position shown by the solid line in FIG. 2 about the optical axis 0--0. Then, the image formed image tA
s is changed in attitude by 90 degrees around the optical axis 0-0 with respect to the light-receiving surface range 7 of the sensor 6, and becomes vertical, and the light-receiving surface range 7
As a result, the image information can be read without any problems as described above. If the formed image AI is upside down relative to the light-receiving surface range 7 of the sensor 6, the orientation can be corrected by rotating the prism 5 by 90'.

[Problem that the invention seeks to solve]

By the way, in the conventional device as described above, since it is necessary to provide the prism 5, which is an optical member for image rotation, on the optical path between the magnifying projection lens 4 and the -dimensional image sensor 6, Since the angle of view of the incident light is large, the prism 5 becomes large, making it difficult to maintain high resolution and also becoming very expensive, which poses a serious problem in terms of product cost.

The present invention solves this problem.

Summary: Structure of the Invention [Means for Solving the Problems] The present invention uses a one-dimensional image sensor as an image reading means, and uses image information photographed on a microfilm in the light-receiving surface area of the sensor for image rotation. In an image reading device that forms an image using an enlarged projection optical system that includes an optical member, and reads the formed image information using the one-dimensional image sensor described above in main scanning and sub-scanning, the one-dimensional image sensor is read from the microfilm side. A reduction projection optical system, an image rotation optical member, and an enlargement projection optical system are arranged in order from the microfilm side on the optical path leading to An image is formed on the light receiving surface area. The gist of the present invention is an image reading device characterized by the following features.

[Effect]

That is, an image information frame photographed on a microfilm is once reduced by a reduction optical system, and then the light is guided to an optical member for image rotation to perform the necessary image direction change, and then the light after the image direction change is By configuring the optical system to enlarge and project the image onto the light-receiving surface range of the one-dimensional image sensor using the enlargement projection optical system, the angle of view from the reduction optical system to the image rotation optical member becomes smaller, and therefore the image rotation optical member Therefore, it becomes possible to reduce the size and weight of the device, maintain high resolution, and reduce product cost.

〔Example〕

FIG. 1 shows a schematic configuration of an embodiment of the apparatus according to the present invention, and constituent members common to the apparatus shown in FIG.

Reference numeral 8 denotes a reduction lens as a reduction optical system, and in the optical path from the microfilm 1 side to the one-dimensional image sensor 6 side, from the microfilm side, the above-mentioned reduction lens 8, then the prism 51 as an optical member for image rotation, and then the magnification. A projection optical system is constructed by disposing a magnifying projection lens 4 as a projection optical system. The usage and function are the same as the device shown in the example shown in FIG.

In this embodiment, a prism is used as the image rotation means 5, but the same effect can be obtained by using an image rotation means using a plurality of mirrors.

C. Effects of the Invention As described above, the invention has not only made it possible to eliminate the drawbacks of the conventional device described above, but also made it possible to reduce the weight of the product.

[Brief explanation of drawings]

FIG. 1 is a side view showing a schematic configuration of the essential parts of an apparatus according to an embodiment of the present invention, FIG. 2 is a view of the conventional apparatus, and FIGS. 3 and 4 are optical path diagrams of an image rotation prism, respectively. , FIG. 5 is an explanatory diagram of the relationship between the light-receiving surface range of the one-dimensional image sensor and the image formed in a horizontal orientation, and FIGS. 6(a) to 6(d) are microfilms on which image information is photographed and recorded in a vertical orientation. FIG. 3 is a partial plan view showing various examples of microfilms photographed and recorded in landscape orientation. 1 is a microfilm, A is an image information frame, 3 is an illumination light source, 4 is an enlarged projection lens, 5 is an image rotation prism, 6 is a one-dimensional image sensor, 7 is a light receiving surface range of the sensor, and 8 is a reduction projection lens. Fig. 5 Fig. 2 ■ Fig. 4 Child * 'q rc

Claims (1)

[Claims] (1) A one-dimensional image sensor is used as an image reading means, and image information taken on a microfilm is imaged on the light-receiving surface area of the sensor by an enlarged projection optical system including an optical member for image rotation. In an image reading device that uses the one-dimensional image sensor described above to read image information in main scanning and sub-scanning, a reduction projection optical system and an image sensor are installed in the optical path from the microfilm side to the one-dimensional image sensor in order from the microfilm side. A rotating optical member and an enlarged projection optical system are installed.
An image reading device characterized in that image information captured on a microfilm is formed on a light receiving surface range of a one-dimensional image sensor via the three devices.