JPS6096073A - Picture reader - Google Patents

Abstract

PURPOSE:To always attain constant resolving power and to eliminate an intricate lens exchange means and a position sensor by always forming projected pictures of recorded pictures of a microfilm, documents, etc., in the fixed sizes in the main or sub-scan direction of a line sensor. CONSTITUTION:A motor is connected to a motor controller 23 and driven by turning on a magnification operation button 24. The driving of the motor moves independently a lens and line sensor so that their relative positions are changed against a film retaining part 21, and adjusts the size of a projected picture on the line sensor. While the light reflected by a half mirror 25 is reflected respectively by mirrors 27, 28, and 29 to create projected pictures on a screen 30. The mirror 28 is designed to be movable relatively to the fixed mirrors 27 and 29 and is set at a position by the driving system so that the light path length from a half mirror 25 to a line sensor 26 and the light path length from the mirror 25 to a screen 30 may be equal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image reading device, and particularly to a device that reads a projected image of a 4-microfilm, document, etc. using a one-dimensional line sensor such as a CCD, and extracts it as a digital signal.

In general, microfilm includes /Ototo Film, 35
There are various types such as RRAN film and microfiche, and there are also various recording reduction ratios. Therefore, the size of the image recorded on the microfilm is not constant and varies depending on the type of film, the reduction ratio, etc. If the projection system including the projection lens is fixed, the size of the projected image will follow the size of the recorded image.

Specifically, FIGS. 7 and 2 show microfilm projection systems. / is a projection lens, 2 and 2 are images of different sizes recorded on microfilm, 2 and 3' are recorded images and 3 are projected images, and the reading section of the line sensor is located at this position. is set. When the projection system is fixed in Figures 1 and 2, when the recorded image size changes from a to 3, the projected image size also changes from Z to 3'.
It changes to.

Therefore, in the past, it was necessary to change the main scanning area and sub-scanning area of the line scanner depending on the size of the recorded image, and it was necessary to further provide a position sensor, a sum circuit, etc. for this purpose. There were drawbacks.

The failure lIj was made to eliminate the above-mentioned drawbacks, and is achieved by changing the relative positions of the image to be read recorded on the film, the projection optical system, and the line sensor scanning surface. , a projected image of the image to be read is formed on the scanning surface of the line sensor with a constant size in the main scanning direction or the tv') scanning direction, so that the scanning area of the line sensor is The purpose is to provide an image reading device that changes according to the size.

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 6 is a schematic diagram showing an embodiment of the present invention.

Here, the light from the light source 20 illuminates the recorded image on the film placed in the film holding section 2/, and the transmitted light passes through the projection lens (not shown) in the lens section 22 and the half mirror 2. Then, a projected image of the recorded image is formed on the light receiving surface of a line sensor (not shown) in the line sensor unit. Here, the lens section 22 includes the above-mentioned projection lens (not shown), a motor and a drive system for moving the projection lens. The line sensor section 2B includes the line sensor (not shown), a motor for moving the line sensor, and a drive system. Each of the above-mentioned motors is connected to the motor control section 23, and is driven when the magnification conversion operation button 2 is pressed. By driving the motor, the lens and line sensor can be independently moved to change their respective relative positions with respect to the film holder 2, and the size of the projected image on the line sensor can be adjusted. .

On the other hand, the light reflected by the half mirror 25 is reflected by the mirror 2'
/, 2g and U9 are reflected on the screen 3.
A projected image is formed on 0.5V:, None. The mirror 2g is movable relative to the fixed mirror 2'22q, so that the optical path length from the half mirror 2S to the line sensor section B is equal to the optical path length to the screen 30. The position is set by a drive system (not shown).

This is achieved by making the size of the projected image on the screen 30 equal to the size of the projected image on the line sensor.
This allows the size of the projected image on the line sensor (more precisely, on the scanning surface of the line sensor) to be easily grasped at a glance.

An embodiment of the screen 30 described above is shown in FIG. - The image projected onto the screen 30 is the same as the image projected onto the scanning surface of the line sensor, so the image of the screen 30 is actually the scanning surface of the line sensor. It can be thought of as a surface. Therefore, the first index L has a width that matches the width of the scanning range of the line sensor, and the first index L has a width that matches the width of the scanning range of the line sensor.
Screen 30" Also, the first index, L
A plurality of th indices M, , M2 . M3 and the like are provided on the screen 30 parallel to each other and aligned with the main scanning direction X of the line sensor. In FIG. 7, the first index R and the a-th index M, ,
M2. The center of the rectangular area surrounded by M3 etc.
It overlaps the center C of the screen 30, and the center of the projected image is also made to coincide with the center C. Furthermore, most of the recorded images are J.
Considering that the shape is similar to the paper size according to IS (for example, A-B5, etc.), it is desirable that the rectangular range is also similar in shape.

Next, regarding the operation and operation flow of the above embodiment,
This will be explained with reference to FIGS. 3 and 7.

(1) First, the recorded image on the film set in the film cleaning section 2/ is projected onto the screen 30 via the lens and each mirror.

(11) Check whether the width of the projected 1IllI image on the screen 30 in the main scanning direction X matches the range determined by the first index L.

songs) If they do not match, double/convert operation button 2
Press the button. Then, the motors provided in the lens section 22 and the line sensor section 2A are activated by the motor control section and the motor control section 2B, respectively.
3, the lens section 22 and the line sensor section move.

Iv) Due to the above movement, the relative positions of the film, lens, and line sensor change, and the size of the projected image formed on the line sensor changes.

Accordingly, the size of the projected image on the screen 30 also changes accordingly.

(vl When the size of the projected image on the screen 30 matches the range delimited by the first index, release the two magnification conversion operation buttons.

(The projected image shown in vt- is the second index M, , M2.M3
Check which ranges separated by , etc. match.

! /*+ 1- Use a switch, etc. not shown, to operate the sub-scanning drive system of the line sensor, and perform sub-scanning I.
'r Set the range. The above-mentioned switches include second indicators M, , M2. The sub-scanning range may be set by providing a plurality of switches in one-to-one correspondence with M3, etc., and selecting an appropriate one from among them.

The drive speed of a drive system (motor), not shown, which performs sub-scanning of the line sensor is controlled according to the set magnification, thereby controlling the sub-scanning speed of the second sensor.

&ii) The reading column 1''11 is completed as described above, and image reading is then started.

Therefore, as explained above, in this embodiment, even if the sizes of the images recorded on the film are different, the main scanning range can always be kept constant and the images can be read.

Therefore, since the number of elements is constant for each life of the line sensor, the effective range can be fully used, and therefore a constant resolution can always be obtained.

In the above embodiment, the main scanning range is constant and the sub-scanning range is variable, but the reverse is also possible. In that case, match the second index to the sub-scanning range and -
only one set is provided, and a plurality of sets of first indicators are provided. Then, the size of the projected image may be adjusted so that the range of the projected image on the screen in the sub-scanning direction matches the second index.

In this case, the specific operation will be explained using the projection system shown in FIGS. 3 to S.

In FIG. 3, the distance between the projection lens / and the recorded image G and the distance between the projection lens / and the projected image G' are assumed to be l. ZS is the sub-scanning range of the line sensor S, which corresponds to the second index shown in FIG.

Therefore, even when using a recorded image larger than the recorded image as shown in FIG.
By changing , using the above-described means, it is possible to obtain a projected image B' having the same size as the projected image q'. Therefore, the line sensor S can perform reading by sub-scanning the scanning range ZS equal to that shown in FIG. In this case, the distance between the recorded image B and the lens is 11
and the distance l between the lens/and the line sensor S! The relationship with 2 is l! ,'>f)>12.

As shown in Fig. S, even if the recorded image 7 is smaller than the recorded image q, by changing the relative position in the same manner as described above, it is possible to obtain a projected image 7' having the same size as the projected image t'. I can do it. The line 7 sensor can be read by scanning the sub-scanning range ZS. In this case, the distance Pm, 13 and the distance I! The relationship with 4 is ls
< l < II.

Note that the sub-scanning range ZS and the distance t4111 l,
z, ~l.

may be determined by considering the performance of the lens, the size of the recorded image, etc. The size of a recorded image is determined by the recording reduction ratio when recorded on film.

As described above, by adjusting the length of the projected image in the sub-scanning direction to a constant value, the sub-scanning area of the line scanner can be fixed. This eliminates the hassle of replacing the projection lens each time a different recorded image and the complexity of the mechanism.

In the embodiment shown in FIG. 6, when changing the projection magnification, the film holding section 2/ is fixed and the lens section 22 and the line sensor section 2B are variably moved. Alternatively, the same effect can be achieved by fixing one of the line sensor units 2B and moving the other unit.

Furthermore, although the simplest optical system was schematically shown in the above embodiment, other optical systems such as mirrors or zoom lenses may be used as necessary if the projected image is to be adjusted to a constant size. In addition, it is also possible to configure an optical system that changes the magnification.

As explained above, the present invention
By making the projected image of a recorded image such as a document always have a constant size in the main scanning direction or sub-scanning direction of the line sensor, it is possible to fix the sub-scanning range when there is a main scanning range. Therefore, firstly, it becomes possible to obtain a constant resolution of 7(J), and secondly, it makes it possible to remove complicated lens exchange means and position sensor snow, which is a very good effect. It is something that plays.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a conventional projection system; FIG. , FIG. 7 shows an embodiment of the screen according to the present invention (this is a 61-type diagram. U θ... light source, 2/... film holding section, 2.2... lens section, 23... Motor control section. 2'l...Magnification conversion operation button, 2k...Half mirror. Kootsu...Line sensor section, 2'7.2g, 29 ・
··mirror. 30... Screen, L... First indicator. M, ,M2. M3...Second indicator. Figure 1 Figure 2 Room 3 Figure 4 Figure 5 Room 6 Figure 7 Procedural amendment (method) February 6, 1980 Director General of the Patent Office Mr., Indication of the case 1982 Patent Application No. 202822
No. 2, Name of the invention Image reading device 3, Jolt corrector] Relationship with 1 Patent applicant (LOO) Canon Co., Ltd. 5, Date of amendment order I" Date of dispatch: 1981 IJ131, 6, Amendment A column for a brief description of the drawings in the subject specification. 7. In the statement of contents of the amendment, page 11, line 14, [1, 1-Figure, I]
Narahini Figure 2” is corrected.

Claims (3)

[Claims] (1) In a device that scans and reads an image to be read with a line sensor via a projection optical system, the projected image of the image to be read is scanned by the line sensor. ,
An image reading device characterized in that it can be deformed to a constant size in the main scanning direction or the sub-scanning direction. (2) By changing the relative positions of the image to be read, the projection optical system, and the scanning surface of the line sensor, the size of the projected image in the main scanning direction or the sub-scanning direction can be made constant. An image reading device according to claim 1, characterized in that the image reading device is configured to do the following. (3) The image reading device according to claim 1 or 2, wherein the line sensor performs main scanning or sub-scanning only within a certain range.