JPH06105082A - Image reader - Google Patents

Abstract

PURPOSE:To obtain accurate shading correction data for transparent document read without enlarging the main body neither paying the cost. CONSTITUTION:A carriage 4 consisting of a lamp as a linear light source of three colors R, G, and B, a mirror 6, a lens 7, and a CCD 8 as the read element is provided under a transparent document base 3 on the upper face of a main body 17 and when a reflective document like a photograph or a printed matter is read, the document is set on the upper face of the first transparent document base 3, and the light of the lamp 5 is thrown to the document through the first transparent document base 3, and the image of reflected light is formed and read on the CCD 8 as the line sensor by changing the optical path by the mirror 6, and the carriage 4 is moved to perform subscanning, and the whole of the document is read.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus capable of reading a reflective original and a transparent original.

[0002]

2. Description of the Related Art As a configuration for obtaining data for shading correction for a transparent original when a transparent original for reading a reflective original is also used when the transparent original is set and read, it is disclosed in JP-A-63-252062. As has been done
A method is disclosed in which a thick transmission reference plate is provided at the end of the document table and the transmitted light from the transmission light source is read as shading correction reference data. For this reason, since the transparent reference plate is naturally provided outside the original reading range of the transparent original table, the reading device becomes large, and the upper surface of the transparent reference plate is a defocus surface, which is used for reading the original. It can't be done and isn't rational. Further, since the conditions of the transparent original reference plate are different from those of the image reading transparent original table, accurate shading correction cannot be performed.

[0003]

A problem to be solved is that a transparent plate for reading reference data for shading correction dedicated to reading a transparent original is required, which is disadvantageous in size and cost of the apparatus. That is,
In addition, accurate shading correction cannot be performed.

[0004]

According to the present invention, there is provided a first transparent original plate and a second transparent original plate for reading a reflective original, and the light from the light source is transmitted through a diffusion plate, and the second transparent original is provided. The light transmitted through the table is read by the reading element as data for shading correction, the light from the light source is transmitted through the diffusion plate to the first transparent original table, and the transparent original is irradiated with the read light. The device is characterized in that it is read as image data.

[0005]

1 is a cross-sectional view showing an embodiment of the present invention, in which a transparent original reading light source device 2 (hereinafter referred to as a light source device 2) is provided above an image reading device main body 1 (hereinafter abbreviated as main body 1). (Omitted)
It shows a state where is mounted.

To explain the structure of the main body 1, a carriage 4 is arranged below the transparent original table 3 on the upper surface of the main body 1.
The carriage 4 includes a lamp 5 which is a line light source of three colors of R, G and B, a mirror 6, a lens 7, and a CCD 8 which is a reading element.
It is composed of. When reading a reflective original such as a photograph or a printed matter, the original is set on the upper surface of the first transparent original table 3 and the light of the lamp 5 is transmitted through the first transparent original table 3 to illuminate the original and the reflected light is mirrored. The optical path is changed by 6 and the lens 7 forms an image on the CCD 8 which is a line sensor for reading, and the carriage 4 is moved to perform sub-scanning to read the whole. The shading correction data at this time is obtained by the reference plate 9 provided outside the original reading range. An image is read by a document pressing plate (not shown) between the light source device 2 and the document so that the document does not float.

On the other hand, the structure for reading a transparent original will be described by using the light source device 2 on the upper part of the main body 1. The end of the light source device 2 has a hinge structure 10, which is detachably attached to the main body 1 so as to be openable and closable. A transparent plate 11 is provided on the bottom surface of the light source device 2 and has R, G, B inside.
It has a second lamp 12 which is a line light source of three colors and has a diffusion plate 13 on the lower surface.
The second carriage 14 having the above is configured to be capable of sub-scanning in synchronization with the carriage 4. A second document table 15 made of the same glass as the transparent document table 3 is provided on the upper surface of the main body 1. First, when the carriage 4 is located below the second document table 15, the second carriage 14 is also synchronized so that the second lamp 12 is located on the optical axis of the image forming system including the mirror 6, the lens 7 and the CCD 8. Moving. In this state, only the second lamp 12 is turned on, and this light is emitted from the diffuser plate 13.
Is transmitted through the transparent plate 11 and the second document table 15 and is read by the image forming system into the CCD 8 as shading correction data for a transparent document. Then, a transparent original such as a positive film is set on the first transparent original table 3, and the second lamp 12 is turned on to read the whole while sub-scanning the carriage 4 and the second carriage 14 in synchronization. ing. The second lamp 12 is a G (green) lamp that requires the most amount of light in order to obtain a good image.
A good image can be obtained because the shading correction data and the transparent original are read by aligning them on the optical axis of the image forming system. Further, the diffuser plate 11 generally has optical characteristics such as transmittance and diffusivity that are not constant. However, since the diffuser plate 11 moves together with the second carriage 14 to read the transparent original document, the original document is always irradiated at the same location, so that a uniform image is obtained. You can also get Further, both a reflective original and a transparent original can be placed on the first transparent original table 3, and even originals of the same size can be read.

FIG. 2 shows a state in which the light source device 2 is removed and an automatic document feeder 16 (hereinafter abbreviated as ADF) is attached to the main body 1. The hinge structure 1 is the same as the light source device 2
It is installed at 0. A document fed by the ADF 16 is configured to be held on the carriage 4 below the second transparent document table 15 while being conveyed on the second document table and the lamp 5 is turned on to read the reflected light from the document. There is. As a matter of course, since the upper surface of the second transparent original table 15 is the original reading surface, it has the same thickness as the first transparent original table 3 so as to be the focus surface.
It is a glass with high height and transmittance. Also, only the length for reading the document conveyed by the ADF 16 is required.
It is composed of a transparent plate thinner than the document table 3. The second transparent original table 15 is also used as a reading window for the ADF 16 on the one hand, and is also used as a window for reading shading correction data at the time of reading the transparent original, so that a transparent plate dedicated to reading the transparent original is not required. A configuration which is advantageous in terms of size and cost of a certain main body 1 is possible. Further, since the optical conditions of the first transparent platen and the second platen are the same, accurate shading correction can be performed.

In this embodiment, the case where the light source device 2 is mounted for reading a transparent original has been described, but the light source of the main body 1 is transmitted and the image forming optical system for the transparent original is provided on the unit side to be mounted. It can also be implemented with a configuration. Further, it is naturally applicable to a monochrome image reading apparatus using a white lamp instead of the three-color lamp, and the light source device 2 is a white light source on the entire surface and the second carriage 14 does not move.

[0010]

As described above, the image reading apparatus of the present invention includes the second transparent original table 1 for reading the original of the ADF 16.
5 is used for reading the shading correction data for the transparent original, the main body 1 does not require a dedicated reading window for reading the shading correction for the transparent original, and the size and cost of the main body 1 are advantageous. Moreover, the shading correction data can be obtained accurately.

[Brief description of drawings]

FIG. 1 is a sectional view of a reading device showing a configuration of the present invention.

FIG. 2 is a diagram showing a reading device when an ADF is attached according to the present invention.

[Explanation of symbols]

 1 Main body of image reading device (main body) 2 Light source device for reading transparent originals (light source device) 3 First transparent original table 15 Second transparent original table 16 Automatic original document feeder (ADF)

Claims (2)

[Claims] 1. A first transparent platen and a second platen for reading a reflective original.
A transparent document table, the light from the light source is transmitted from a diffusion plate, and the light transmitted through the second transparent document table is read by a reading element as data for shading correction,
An image reading apparatus characterized in that light from the light source is transmitted through the diffusion plate to a transparent document table to illuminate a transparent document, and the transmitted light is read as image data by a reading element. 2. The image reading apparatus according to claim 1, wherein the second transparent document table is a document table for reading a document conveyed by an automatic document conveying device.