JP2003018367A - Original reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader that can prevent a mirror image even when reading an original in a reverse direction and prevent shift of each color in a color image. SOLUTION: The image reader is provided with a light source (light source lamp 2) for illuminating an original, running bodies (1st, 2nd carriages 3, 4) for scanning the face of the original, an optical system for leading a reflected light from the face of the original to a prescribed position (image forming lens 5), and a linear line sensor (CCD 6) with a plurality of light receiving elements in the main scanning direction placed at the prescribed position, and has a 1st mode where the original is fixed and the reader scans the face of the original while moving the running bodies and a 2nd mode where the running bodies are fixed and the reader scans the face of the original while moving the original. The image reader is provided with a memory means (FILO memory 24) that outputs image signals in the reverse sequence to the input sequence. This invention includes two other claims.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document reading apparatus, and more particularly to a light source for illuminating a document surface, a traveling body for scanning the document surface, and an optical system for guiding light reflected from the document surface to a predetermined position. A first mode in which a one-dimensional line sensor having a plurality of light receiving elements arranged in a main scanning direction at a predetermined position is provided, and a document is fixed and the traveling body is scanned while scanning the document surface; The present invention relates to a document reading apparatus having a second mode of scanning the document surface while moving the.

[0002]

2. Description of the Related Art In a document reading device, a document placed on a contact glass is scanned and read by moving a traveling body (carriage) provided under the contact glass. On the other hand, when the automatic document feeder is installed in the document reading device, the traveling body is fixed and the document is read by the traveling body while the original document is conveyed by the automatic document feeder.

In order to read the entire surface of the original, the original and the moving body must be moved relative to each other. For the reading, as described above, the first mode of fixing the original and moving the moving body,
There are two modes, that is, the second mode of fixing the traveling body and moving the original (conveying). In the case of a spread book document, only the first mode can be used, but in the case of a sheet document, either mode can be used.

By the way, in the first mode and the second mode, it is general that the scanning directions of the original document are reversed (although the scanning directions can be matched). That is, when a document is set on the contact glass of the document reading apparatus shown in FIG. 1 to be described later with its front end on the right side, the traveling body located at the left end (home position) in the first mode moves from the left end to the right. The document is sequentially read from the rear end side to the front end side while moving in the direction. On the other hand, in the case of the second mode,
The traveling body is fixed to the left end, and the originals conveyed from the front end side are sequentially read by the traveling body from the front end side to the rear end side.

[0005]

As described above, the first
If the normal mode is obtained in the first mode as a result of the original reading direction being reversed in the second mode and the second mode, the left and right sides of the original are reversed in the second mode. There is a first problem that a mirror image is displayed. If a normal image is obtained in the second mode, the same problem occurs in the first mode.

Further, particularly in a digital color copying machine using a 3-line color CCD, the reading order of the sensors for each color is reversed, for example, R, G, B to B, G, R, so that reading is performed in advance. There is a second problem that the relationship between the colors of so-called line-to-line correction, which delays the output of the colors and matches the output of the colors to be read later, is reversed, resulting in an image in which the positions of the respective colors are displaced.

In view of the above, the present invention provides an image reading apparatus capable of preventing the generation of a mirror image even when a document is read in the reverse direction and preventing misalignment of each color in a color image. With the goal.

[0008]

In order to achieve the above object, the invention according to claim 1 is directed to a light source for illuminating the document surface, a traveling body for scanning the document surface, and a light reflected from the document surface at a predetermined position. And a one-dimensional line sensor arranged at a predetermined position in the main scanning direction and having a plurality of light receiving elements, and a first mode for scanning the document surface while fixing the document and moving the traveling body. In a document reading apparatus having a second mode in which the traveling body is fixed and the document surface is scanned while moving the document, the read image signal is input and stored, and the image signal is output in the reverse order of the input. A document reading device provided with a memory means is the main feature.

According to a second aspect of the present invention, in the first aspect, the main feature of the document reading device is that the document is conveyed in the second mode by an automatic document feeding device mounted on the main body of the device. .

According to a third aspect of the present invention, in the first or second aspect, the one-dimensional line sensor is provided with three lines for reading a color original, and the image signal is stored and delayed for each line and output. The document reading apparatus, which is provided with a delay unit and has a different delay amount of an image signal between the first mode and the second mode, is a main feature.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, a document reading device provided with an automatic document feeding device is targeted, but of course the invention is not limited to this mode.

FIG. 1 shows a mechanical diagram of a document reading apparatus having a general automatic document feeder. A light source lamp 2, a first carriage 3, a second carriage 4, an imaging lens 5 and a CCD 6 are provided inside the main body 1 of the document reading apparatus.
A contact glass 7 is provided on the upper part of the.

In such a structure, the entire surface of the original is read by moving the first carriage 3 and the second carriage 4 to the right in the figure by the motor 8. That is, while moving the first carriage 3, the light source lamp 2 illuminates the document surface, and the reflected light is reflected by the reflection mirrors of the first and second carriages 3 and 4, and guided to the imaging lens 5.
A document image is formed on the CCD 6 and photoelectrically converted to obtain the document image as an electric signal. In the following description, the above document reading method is referred to as a carriage method (first mode).

An automatic document feeder 10 is mounted on the contact glass 7. Since the configuration itself of the automatic document feeder 10 is well known, its description is omitted. When the automatic document feeder 10 is used, the first and second carriages 3 and 4 of the main body 1 are fixed at a certain position (for example, home position), the light source lamp 2 is turned on, and the document is fed from the automatic document feeder 10. The original is read by being conveyed onto the contact glass 7. In the following description, the above document reading method is referred to as a sheet through method (second mode).

When the automatic document feeder 10 is mounted on the document reading apparatus 1, normally, the former carriage method is used for book originals that cannot be used by the automatic document feeder 10, and the latter sheet method is used for sheet originals. Through method is used properly. The optical image obtained by the image reading of these methods is read by the CCD 6 and photoelectrically converted to obtain an image signal as described above.

FIG. 2 shows a block diagram of a general circuit of the color original reading apparatus. The image read by the CCD 6 of each color is processed by the image signal processing unit 20 for each color, and the AD converter 21 performs analog / digital conversion to obtain a digital image. After that, there is an interline memory 22 for correcting the preceding G and R positions with respect to the position read by the B line. The interline memory 22 delays G and R and corrects the spatial reading position in accordance with the output timing of B. Further, there is a shading correction unit 23 that corrects the sensitivity of each pixel of the CCD 6 and outputs image data. The configuration of the black and white document reading device is also the same, and as is clear from the CCD 6 to the shading correction unit 23 in FIG. 3, there is one system after signal processing,
In addition, the interline memory 22 becomes unnecessary.

By the way, in the apparatus shown in FIG. 1, the relationship of the vertical direction in which the CCD 6 reads the original is opposite when the original is read by the carriage method and when the original is read by the sheet through method. Then, the same problem as the problem of the conventional example occurs.

FIG. 3 is a block diagram of a circuit of the black and white document reading apparatus according to the present invention. The difference from the above-described conventional example is that a FILO (first-in, last-out) memory 24 is added after the shading correction unit 23. The FILO memory 24 is a memory for outputting in the reverse order of the input order.

As described above, since the scanning direction is opposite between the carriage system (first mode) and the sheet through system (second mode), image data can be read in reverse. Therefore, by using the FILO memory 24, for example, in the case of the sheet through method, if the image data is output in the reverse order, a normal image similar to the case of the carriage method can be obtained.

At this time, since the right and left can be reversed in units of one line, the amount of memory can be at most 10 Kbytes, and if it is built in another LSI or the like, there will be little cost increase. When reading by the carriage method, the processing of the FILO memory 24 is of course through.

FIG. 4 is a block diagram of a color original reading apparatus according to the present invention. In the conventional block shown in FIG. 2, an interline memory 22 is added to the B system, and
The FILO memory 24 is added as in the case of the black and white document reading apparatus. First, when reading by the carriage method, R and G are delayed and B is through as in the conventional case. Next, when reading by the sheet through method, B and G are delayed and R is through. The handling of the FILO memory 24 is the same as that of the monochrome original reading apparatus.

[0022]

As described above, according to the first and second aspects of the present invention, the light source that illuminates the document surface, the traveling body that scans the document surface, and the reflected light from the document surface are at predetermined positions. And a one-dimensional line sensor arranged at a predetermined position in the main scanning direction and having a plurality of light receiving elements, and a first mode for scanning the document surface while fixing the document and moving the traveling body. In a document reading apparatus having a second mode in which the traveling body is fixed and the document surface is scanned while moving the document, the read image signal is input and stored, and the image signal is output in the reverse order of the input. Since the memory means (FILO memory) is provided, it is possible to prevent the generation of the mirror image even when the document is read in the reverse direction.

According to the third aspect of the invention, the one-dimensional line sensor is provided with three lines for reading the color original document, and is provided with delay means for storing and delaying the image signal for each line, and outputting the delayed image signal. Since the delay amount of the image signal is made different between the mode 2 and the second mode, it is possible to prevent the positional deviation of each color in the color image.

[Brief description of drawings]

FIG. 1 is a mechanism diagram of a document reading device with a general automatic document feeder.

FIG. 2 is a block diagram of a general circuit of a color original reading device.

FIG. 3 is a block diagram of a circuit of a monochrome original reading apparatus according to the present invention.

FIG. 4 is a block diagram of a circuit of the color original reading apparatus according to the present invention.

[Explanation of symbols]

1 body 2 light source lamp 3 First carriage 4 second carriage 5 Imaging lens 6 CCD 7 contact lenses 8 motor 10 Automatic document feeder 22 Line memory (delay means) 24 FILO memory (memory means)

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) G06T 1/60 450 H04N 1/00 108M H04N 1/00 108 1/21 1/21 1/12 Z

Claims (3)

[Claims] 1. A light source for irradiating a document surface, a running body for scanning the document surface, an optical system for guiding reflected light from the document surface to a predetermined position, and a plurality of light receiving units arranged at the predetermined position in the main scanning direction. A one-dimensional line sensor having an element, which scans the document surface while fixing the document and moving the traveling body, and a second mode which scans the document surface while fixing the traveling body and moving the document. A document reading device having a mode, the document reading device further comprising a memory means for inputting and storing a read image signal and outputting the image signal in a reverse order of the input. 2. The document reading apparatus according to claim 1, wherein the document is fed in the second mode by an automatic document feeder mounted on the apparatus main body. 3. The one-dimensional line sensor according to claim 1, wherein the one-dimensional line sensor is provided with three lines for reading a color original document, and is provided with delay means for storing and delaying an image signal for each line, and outputting the delayed image signal. An original reading apparatus characterized in that a delay amount of an image signal is different between the first mode and the second mode.