JPH04153639A - Image reader - Google Patents

Abstract

PURPOSE:To easily carry out a correction with a simple means, to read a transmission original having high image quality, and further, to prevent the damage of the original caused by heat by moving the reflecting mirror of the reading optical system of a reflection original to a position for receiving transmitting light exiting from a stick-like light source and transmitting the transmission original, and forming the reading optical system of the transmission original. CONSTITUTION:A scanning device 42 for carrying in the direction of the arrow (c), that is, a scanning direction almost perpendicular to the longitudinal direction of the stick-like light source 40, and for scanning the full surface of the transmission original with irradiating light from the stick-like 40, is disposed on the lower part of the stick-like light source 40. A means stopping the optical system of a reader main body 12 such as a light source 20 and a mirror unit 22 at a position capable of reading the transmitting light of the transmission original, that is, the position capable of receiving the transmitting light T of the transmission original from a transmission original unit 16, is provided. Thus, the efficiency of the light is high, and the light source of a low light quantity can be applied. Further, the transmission original is prevented from being deformed with the heat, or its image is prevented from being damaged.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is a printing plate bag! The present invention relates to an image reading device that is applied to copying machines and the like, and is capable of reading original images of both reflective originals and transparent originals.

<Prior Art> In recent years, image reading devices applied to printing plate-making devices and copying devices are capable of reading images not only of reflective originals such as photographs and printed matter, but also of transparent originals such as reversal film and negative film. That is required.

Conventionally, reading of transparent originals in various image reading apparatuses is performed by a light source unit for transparent originals as shown in FIG. 4, which utilizes an optical system for reading reflective originals.

The light source unit 100 basically includes a light source 102 such as a halogen lamp, a diffuser plate 104, and a housing 106. This is performed by illuminating the original A from above and reading the transmitted light of the transparent original A using the optical system of the image reading device 108.

In other words, the light emitted from the light source 102 is transmitted to the diffuser plate 104.
The light is diffused and illuminates the transparent original A placed on the original platen 110, and is transmitted through the transparent original A. The transmitted light T of the transparent original A is
The light source unit 11 passes through the slit 116 of the light source unit 114 (the light source is not lit) for reflective originals moving in the direction of arrow a.
The light is reflected by a mirror 118 that moves integrally with the light source 114, enters the mirrors 120 and 122 that move at 1/2 the speed of the light source 114 in the direction of arrow a, is reflected in a predetermined direction, and enters the CCD camera 124. The image is then photoelectrically converted and processed as image information.

In the illustrated reading device, the light source section 1
14 in the direction of arrow a, the transmitted light T of the transparent original A is sequentially incident on the CCD camera 124, and the image information carried by the transparent original A is read over the entire surface.

<Problem to be solved by the invention> Such a light source unit 100 is used for reading the transparent original A
By applying this, it is possible to read the image of the transparent original A using a unit with an extremely simple configuration by applying a normal optical system for reading reflective originals.

However, in such a light source unit 100, since the transparent original A is irradiated by one light source 102, even if the diffuser plate 104 is used, the entire surface of the transparent original A cannot be irradiated with a uniform amount of light. Moreover, correcting the two-dimensionally distributed light amount requires complicated means, and if this is not done, there is a problem that the image quality will deteriorate, especially when high image quality is required for printing plate making equipment, etc. This poses a problem in applications where

Furthermore, in order to irradiate the entire surface of the transparent original A with a sufficient amount of light, the light source 102 needs to have a large amount of light, so the transparent original A may be deformed or damaged by the heat of the light 'a102. Furthermore, since it is a surface illumination, there is also the problem that the light efficiency is poor.

An object of the present invention is to solve the problems of the prior art as described above.Since the light efficiency is high, a light source with a low light amount can be applied, and since the light amount of the light source is distributed one-dimensionally, it is easy to use. An image reading device that allows for easy correction using various means, can read transparent originals with high image quality, and does not damage the originals due to heat! Our goal is to provide the following.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides an image reading device capable of reading image information carried on a reflective original and a transparent original. a bar-shaped light source, a scanning means for conveying a transparent original in a direction substantially perpendicular to the longitudinal direction of the bar-shaped light source, and a housing in which the rod-shaped light source and the scanning means are housed, and an original table on which the reflective original is placed; A replaceable transparent original unit is provided, and the reflective mirror of the reflective original reading optical system is moved to a position where it receives the transmitted light emitted from the rod-shaped light source and transmitted through the transparent original, and the transparent original reading optical system is operated. An image reading device is provided.

Further, it is preferable that the transparent original is conveyed by the scanning means on the same plane as the original table surface.

<Operation of the Invention> In the image reading device of the present invention having the above-mentioned predetermined configuration, image reading of a reflective original is performed in the same manner as in a normal reading device. On the other hand, when reading transparent originals,
The document table for reflective documents is removed, and in place of this document table, a transparent document unit having a fixed bar-shaped light source and a means for scanning and transporting transparent documents is loaded, and a reflective mirror of the reading optical system for reflective documents is used. This constitutes an optical system for reading a transparent original.

This transparent original unit scans and conveys the transparent original in a direction substantially perpendicular to the longitudinal direction of the rod-shaped light source using a scanning means, so that the entire surface of the transparent original is scanned with light from the rod-shaped light source. Here, the reflective original reading optical system is moved to a predetermined position where it can receive the transmitted light of the transparent original,
The optical path of this transmitted light is adjusted by a slit in the light source section, a reflective mirror, etc. arranged in the optical system of the reflective original, and it travels along the same optical path as the reading light of the reflective original and enters a photoelectric conversion device such as a CCD camera. The image is read out as image information, or an image is formed at a predetermined exposure position to expose a recording material such as a photosensitive material.

According to the image reading apparatus of the present invention using such a transparent original unit, since a fixed rod-shaped light source is used to scan the transparent original by moving the original, compared to the conventional image reading apparatus that uses surface illumination, The light efficiency is high, a light source with low light intensity can be applied, and the transmission document will not be deformed by heat or its image will be damaged.

In addition, since the rod-shaped light source is fixed, there is no change in light intensity unevenness that occurs when scanning a transparent original (shading correction is easy, and once shading correction is performed, it remains in that state for a long period of time). It is possible to read high-quality transparent original images.

<Embodiments> Hereinafter, an image reading device according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

FIG. 1 shows a schematic sectional view of an embodiment of an image reading device of the present invention.

The image reading device 10 shown in FIG.
A device that can read image information carried on both reflective originals such as block originals, and transparent originals such as negative film and reversal film! Basically, it consists of a reading device main body 12, a document table 14 (see FIG. 2) on which a reflective original is placed, which is installed in an opening 15 on the upper surface of the reading device main body 12, and a transmissive original document reading device. It is composed of a transparent original unit 16.

The basic structure of the reading device main body 12 is the same as that of a normal reflective original reading device, and includes a housing 13 and a light source section 20.
, a mirror unit 22 , and a CCD camera 24 . In addition, the reading device main body 12 includes:
When reading an image of a transparent original, a means is provided for stopping the light source section 20, mirror unit 22, etc. at a predetermined position where transmitted light can be read.

The housing 13 is a casing that is made of a light-shielding member and has an opening 15 at the top.

This opening 15 is provided with an original platen 1 when reading a reflective original.
4, when reading a transparent original, the transparent original unit 16
is loaded.

The document table 14 is made of glass or the like, which is used in a typical image reading device for reflective documents, except that the document table 14 is configured to be removably attached to the opening 15 . Note that there are no particular limitations on the method for attaching and detaching the document table 14 to the opening 15 (various known methods are applicable, such as using bolts and nuts, and using fixing members such as hooks). be.

The light source section 2o includes light sources 26a and 26 for reading one reflective original.
b, and a reflector 28, and is indicated by the arrow a(
It is configured to be movable in the scanning direction shown in FIG. Furthermore, a mirror 30 that moves integrally with the light source section 20 is arranged below the light source section 20.

The mirror unit 22 includes two mirrors 32a and 32b.
It moves in the same direction at 1/2 the speed of the light source unit 20 and captures the reflected light R from the reflective original (reading light, shown in FIG. 2 - dotted chain line) or the transmitted light from the transparent original. T (first N: dotted chain line) is reflected in a predetermined direction.

The reflected light R or the transmitted light T reflected in a predetermined direction by the mirror unit 22 enters the CCD camera 24 . The CCD camera 24 has an imaging lens and a COD optical element, and reflected light R or transmitted light T incident thereon is photoelectrically converted, read as image information converted into an electrical signal, and processed.

In such an image reading device 10, when reading a reflective original, the original platen 14 is loaded into the opening 15 as shown in FIG. 2, and the reflective original B is placed at a predetermined position on the original platen 14. After placing the document, cover the document table 14 with the document holder 17,
While moving the light source unit 20 in the direction of arrow a, the reflective original is irradiated with light from the light sources 26a and 26b, and the entire surface of the original is scanned. Reflected light R from the reflective original B passes through the slit 34 of the reflector 28 and is reflected in a predetermined direction by the mirror 30 and the mirror unit 22, and is reflected by the CCD camera 2.
4 and is photoelectrically converted and processed as image information.

In addition, when reading an image of a transparent original, the reading device main body 12 moves the optical system of the reading device main body 12, such as the light source section 20 and mirror unit 22, to a position where transmitted light of the transparent original can be read, that is, a position where the transmitted light of the transparent original can be read. It has means for stopping the transmitted light T of the transparent original from the original unit 16 at a position where it can be received.

In the image reading apparatus 1o of the present invention, a transparent original unit 16 is loaded when reading a transparent original.

The transparent original unit 16 is loaded into the opening 15 from which the original table 14 has been removed, and is composed of a housing 38, a rod-shaped light source 40 disposed within the housing 38, and a transparent original scanning means 42. In the illustrated apparatus, the scanning position of the transparent original is preferably on the same surface as the reflective original placement surface of the original platen 14.

The housing 38 is a light-shielding case, and has a lid 44 on the top for loading a transparent original into the scanning means 42 and a slit 46 on the bottom for the transmitted light T to pass through. It has protrusions 39a and 39b that engage with the upper surface of the housing 13 of the reader main body 12 when loaded. The slit 46 is a slit having a longitudinal direction perpendicular to the paper surface of the first drawing, and allows the transmitted light T of the transparent original to pass therethrough.

In the illustrated transparent original unit 16, the housing 38 is configured to block the entire surface of the opening 15 to block light; however, the present invention is not limited to this, and the rod-shaped light source 40,
Depending on the position of the slit 46 etc., it may be configured and loaded so as to close at least a portion of the opening 15. However, in this case, light from the outside may not enter the reading device main body 12. In order to prevent flare from occurring, it is preferable to provide various light shielding means for the open portion of the aperture 15.

The rod-shaped light source 40 irradiates a transparent original to generate transmitted light T, and is arranged at the top of the housing 38 with its longitudinal direction perpendicular to the plane of FIG. 1. Further, the rod-shaped light source 40 is provided with a glue deflector 41 for efficiently emitting irradiated light in a predetermined direction.

In the image reading bag filO of the present invention, by having such a fixed rod-shaped light source, high light efficiency is achieved and high quality image reading is possible with a low light amount. Furthermore, since the light source is fixed, there is very little variation in the amount of light even when reading is performed, and if the shading correction is performed first, there is no need to perform the correction again over a long period of time.

The rod-shaped light source 40 is not particularly limited, and may be a fluorescent lamp, a rod-shaped halogen lamp, or a number of other sources as long as it can illuminate the entire width of a transparent document of maximum applicable size in a direction substantially perpendicular to the direction of arrow C, which is the scanning direction. Any of various known rod-shaped light sources can be used, such as a combination of a point light source and a fiber array.

Below the rod-shaped light source 4o, there is a scanning device for transporting the transparent original in the direction of arrow C, that is, in a scanning direction substantially perpendicular to the longitudinal direction of the rod-shaped light source 40, and scanning the entire surface of the transparent original with the irradiation light from the rod-shaped light source 40. Means 42 are arranged.

In the illustrated example, as a preferred embodiment, the scanning position of the transparent original is on the same surface as the reflective original placement surface of the original platen 14. With this configuration, by simply stopping the reflective original reading optical system at a predetermined position, it is possible to use these to configure the transparent original reading optical system, and the apparatus can also be made smaller. This allows you to obtain more favorable results.

A schematic plan view of the scanning means 42 is shown in FIG. The scanning means 42 includes a holder 48 that holds the transparent original A, and a drive device 50 that scans and conveys the holder 48 (transparent original A) in the direction of arrow C.

The holder 48 is made of two glass plates that sandwich the transparent original A, or a frame thereof, a frame that can fix the transparent original A, or the like.
The sheet-shaped transparent original A can be made of various types that can transmit the light emitted from the rod-shaped light source 40 and can be held in a flat shape, and can be formed into various forms depending on the driving device 50. Bye. Also, like a so-called slide,
Of course, one having a frame body is also applicable.

As shown in FIG. 3, the drive device 50 includes a roller 52
and 54; belts 56 and 58 stretched across both ends of rollers 52 and 54; motor 60;
The holder 48 holding the transparent original A is attached to the belt 56 by the fixing member 62.
and 58 in a detachable manner. In such a drive device 50, the motor 60 rotates the roller 54 to convey the holder 48 in the direction of arrow C via the belts 56 and 58.

There are no particular limitations on the shapes of the belts 56 and 58 and the fixing member 62 (depending on the shape of the holder 48, etc., they may be configured to reliably support and scan and convey).

The drive device 50 is not limited to one that uses the belt and rollers shown in the example, but may also include one that uses a sprocket gear and chain, one that uses a rack-and-binion, one that uses a drive shaft and a traveling nut,
The irradiated light from the rod-shaped light source 40, such as one to which a pair of rollers is applied, passes through! Any of various known conveying means can be used as long as it has a configuration that allows the transparent original A to be transmitted through.

Further, in the scanning means 42, the holder 48 is not limited to being configured to be detachably attached to the drive device 50, but may be fixed to the drive device 50.

Note that in the image reading device 10 of the present invention, the scanning means 42 is not limited to having the holder 48; for example, a pair of rollers disposed sandwiching the passing position of the transmitted light T is provided, and this pair of rollers is A configuration in which the transparent original A is directly provided to the drive device, such as a method in which the transparent original A is directly nipped and conveyed, may also be used.

When reading the image of the transparent document A using the image reading device ff1lo of the present invention, first, the document table 14 is removed and the transparent document unit 16 is loaded into the opening 15.

Next, the lid body 44 is opened, the holder 48 supporting the transparent original A is placed on the belts 56 and 58, and the fixing member 62 is placed on the belts 56 and 58.
After fixing, the lid body 44 is closed.

When the operator selects the transparent original mode of the image reading device 1o, the optical system of the reading device main body 12, that is, the light source section 2
0 and the mirror unit 22 move to a position where the transmitted light T can be read as shown in FIG. Note that the selection of the transparent original mode may be configured to be automatically performed when the transparent original unit 16 is loaded into the opening 15.

Next, when the switch is turned on, the rod-shaped light source 40 lights up, and after a predetermined period of time, the holder 48 is moved by the drive device 50.
is scanned and conveyed in the direction of arrow C. When the holder 48 moves below the rod-shaped light source 40, the light from the rod-shaped light source 40 illuminates the transparent original A held by the holder 48 and is transmitted therethrough.

The transmitted light T of the transparent original A passes through the slit 34 of the light source section 20, is reflected by the mirror 30 and the mirror unit 22, enters the CCD camera 24 along a predetermined optical path, is photoelectrically converted, and is read as image information. Note that at this time, the light sources 26a and 26b for reflective originals are turned off.

By transporting the holder 48 in this manner, the entire surface of the transparent original A held therein is sequentially scanned with light from the rod-shaped light source 40, and the transmitted light T is read by the CCD camera 24, and the entire surface of the transparent original A image information is read.

In the image reading device 10 of the present invention, the placement position of the transparent original unit h16 on the original platen 14 is
0, a predetermined position defined by the position of the slit 46, etc. Therefore, it is preferable that various positioning means be provided on the upper surface of the housing 38 and/or the reader main body 12 so that the transparent original unit 16 can be easily placed in a predetermined position. There is no particular limitation on the positioning means, and any known means such as a positioning bin, a corresponding rear part, a protrusion, a groove, or even a visual mark can be applied.

Further, in the illustrated image reading device 10, the scanning position of the transparent original is preferably flush with the reflective original placement surface of the original platen 14, but the present invention is not limited to this. Instead, the scanning position of the transparent original and the reflective original placement surface may be different. In this case, for example, a method of configuring the mirror unit 22 to be independently movable to adjust the optical path length of the transmitted light T;
A method of providing a focal position adjustment means such as a lens in the optical path of
Alternatively, the optical path length of the transmitted light T may be adjusted using a method such as providing a CCD camera with a zoom function or the like, thereby making it possible to adjust the focal position.

Further, although the illustrated image reading device is a digital image reading device using a CCD camera, the present invention is not limited to this, and the present invention is an analog slit scanning device that can be applied to various copying devices, etc. Of course, the present invention may also be applied to a type of image reading device.

Although the image reading device according to the present invention has been described in detail above, the present invention is not limited thereto, and various changes and improvements may be made without departing from the gist of the present invention. Of course.

<Effects of the Invention> As explained in detail above, according to the image reading device of the present invention, a bar-shaped light source is used to scan the transparent document by moving the document, so that it is different from conventional reading devices that perform surface illumination. In comparison, it is possible to read the image of a transparent original with high light efficiency, and therefore, a light source with a lower light intensity can be applied than when applying surface exposure, and the transparent original will not be deformed or the image will be damaged. .

In addition, since a fixed, low-light rod-shaped light source is used, there is little change in the light intensity distribution, and shading correction is easy. Readable.

Preferably, by making the scanning position of the transparent original and the reflective original placement surface of the document table the same surface, the scanning optical system for the reflective original can be simply stopped at a predetermined position, and the scanning position of the transparent original can be used to scan the transparent original. It is possible to configure a reading optical system of 1, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, , e.g.,, e.g.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing an example of reading a transparent original in an image reading apparatus according to the present invention. FIG. 2 is a schematic cross-sectional view showing an example of reading a reflective original in the image reading device shown in FIG. FIG. 3 is a schematic plan view showing an example of the scanning means of the image reading device shown in FIG. 1. FIG. 4 is a schematic cross-sectional view of a conventional image reading device. Explanation of symbols 10.108... Image reading device, 12... Reading device main body, 13.38, 106... Housing, 14.110.
... Document table, 15... Opening, 16... Transparent document unit, 17... Document holder, 18... Optical path switching mirror 20.114... Light source section, 22... Mirror unit, 24 .124... COD camera, 26a, 26b, 102... = light source, 28.41... reflector, 30.32a, 32b, 118° 120.122... mirror 34.46, 116... slit, 36... Support shaft, 40... Rod-shaped light source, 42... Scanning means, 44... Lid, 48... Holder, 50... Drive device, 52.54... Roller, 5658 ...Belt, 60...Motor, 62...Fixing member, A...Transparent original, B...Reflective original, T...Transmitted light, R...Reflected light Fl(3

Claims (2)

[Claims] (1) An image reading device capable of reading image information carried on a reflective original and a transparent original, which includes a rod-shaped light source for reading the transparent original, and a transparent original in a direction substantially perpendicular to the longitudinal direction of the rod-shaped light source. It has a scanning means for conveying, and a housing in which the rod-shaped light source and the scanning means are housed, and a transmissive original unit that is replaceable with an original table on which the reflective original is placed, and the transmissive original that is emitted from the rod-shaped light source. An image reading apparatus characterized in that the transmissive original reading optical system is configured by moving a reflective mirror of the reflective original reading optical system to a position where it receives transmitted light transmitted through the transmissive original. (2) The image reading device according to claim 1, wherein the scanning unit transports the transparent original on the same plane as the original table surface.