JP2003078729A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader that can provide a margin to an operation of a running body by moving a reference board with the running body on which a light source is placed. SOLUTION: When the running body on which an illumination lamp 2 integrated with a first mirror 3 is mounted, a white reference board 51 adhered to a transparent base member 52 is placed between an original face and a first carriage. The white reference board 51 and the base member 52 are operated in the same direction as the first carriage on a rail in parallel with a rail on which the first carriage rides. The moving speed of the white reference board 51 is slower than a moving speed of the running body and the moving range of the white reference board 51 is decreased to provide a margin to the configuration of the machine of the image reader. Since the different speeds are used, either of them is earlier moved, reading at a different position of the white reference board 51 is attained and correction of image levels is stabilized by averaging positions with/without dirt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device such as an image scanner, a PPC and a facsimile, and more particularly to a device for stabilizing an output correction operation from a photoelectric conversion element.

[0002]

2. Description of the Related Art Conventionally, in an image reading apparatus of this type, a traveling body carrying a light source moves to sequentially illuminate a document and also a reference plate. The reflected light of the reference plate is read and the output from the photoelectric conversion element is corrected to deal with stains on the platen glass. The position of the reference plate is fixed. Therefore, in order to make the correction, the traveling body needs to move to a position where the reference plate can be reflected.

It is conceivable to solve this problem by using a wide reference plate, but the fact is that such a measure cannot be taken due to the restrictions of the component structure in the apparatus. Therefore, the correction operation cannot be performed with a margin.

The present invention has been made in view of the above-mentioned conventional problems, and provides an image reading apparatus capable of giving a margin to the operation of the traveling body by moving the reference plate together with the traveling body carrying the light source. The purpose is to

[0005]

In order to achieve the above-mentioned object, the image reading apparatus according to the first aspect of the present invention illuminates the document in sequence by moving the traveling body on which the light source is mounted. The reference plate is also illuminated, and the reflected light of the illuminated original is reflected by a plurality of mirrors to reach a photoelectric conversion element such as a CCD, and the reflected light of the reference plate is used as reference reflected light to output from the photoelectric conversion element. In the image reading apparatus for correction, the reference plate is movably arranged in the same direction as the traveling body, and the moving speed of the reference plate is different from that of the traveling body.

According to a second aspect of the present invention, in order to achieve the above object, the image reading apparatus according to the first aspect is characterized in that the moving speed of the reference plate is slower than that of the traveling body.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of a color image reading apparatus according to the present invention. First, the configuration of the scanner body will be described. The original placed on the platen glass 8 is
Irradiation is performed by an illumination lamp 2 which is integrated with the mirror 3. The reflected light is scanned by the first mirror 3, the second mirror 5 and the third mirror 4 which are integrally formed. After that, the reflected light is focused by the lens 1 and is radiated to the SBU 10, which is a CCD drive unit equipped with a color CCD, and R
Photoelectric conversion to GB. The first mirror 3, the illumination lamp 2, the second mirror 5, and the third mirror 4 are movable in the left-right direction in the drawing by using the traveling body motor 9 as a drive source.

Next, the structure of the ARDF (Automatic Double Sided Document Feeder) will be described. Document guide 1 on platen 17
When the single-sided original reading is selected, the originals stacked along 2 are reflected by the calling roller 14, the feeding roller 15 by the paper feed belt 16, the separating roller 17, and the DF original glass 6 by the first conveying roller 18. The second transport roller 21 and the paper discharge roller 23 are passed through the reading position between the guide plate 20 and the guide plate 20.
Sent to and discharged. In the figure, 19 is a registration sensor and 22 is a paper discharge sensor.

On the other hand, when the double-sided original reading is selected, the front side of the original is first read in the same manner as when the single-sided original reading is selected. First, reading of the front surface of the original will be described. A conveying roller 15, a separating roller 17, and a DF original glass 6 and a reflection guide plate 20 by the calling roller 14 and the paper feed belt 16 by the first conveying roller 18.
Through the reading position between the branching claw 2 and the second transport roller 21 and the paper discharge roller 23 without discharging the document.
4 is switched downward and is transferred onto the reversing table 26 by the reversing roller 25. The trailing edge of the document is the discharge roller 2
After passing through 3, the branch claw 24 is switched to the upper side, and the reversing roller 25 is once stopped.

Next, the reading of the back side of the original will be described. In order to read the back side of the document, the reversing roller 25, which has been stopped once, is rotated in the opposite direction to convey the document from the reversing table 26 toward the first conveying roller 18, and further 1 transport roller 18
After passing through the reading position between the DF original glass 6 and the reflection guide plate 20 like the front surface, the sheet is fed to the second transport roller 21 and the paper discharge roller 23, and then the original is discharged.

The original is illuminated by the illumination lamp 2 which is moved in the vicinity of the reading position when passing the reading position between the DF original glass 6 and the reflection guide plate 20 for reading the front surface and the back surface. The reflected light is scanned by the first mirror 3, the second mirror 5 and the third mirror 4 which are integrally formed. After that, the reflected light is focused by the lens 1, and is irradiated onto the SBU 10 in which the color CCD is mounted to be photoelectrically converted into RGB.

The sheet feeding mechanism of the ARDF calling roller 14, the sheet feeding belt 16, the conveying roller 15, and the separating roller 17 are driven by a sheet feeding motor (not shown). In addition, the first transport roller 18, the second transport roller 21, the paper discharge roller 23,
The transport mechanism of the reversing roller 25 is driven by a transport motor (not shown). Further, in the ARDF, a set sensor 13 for detecting whether a document is set on the document table 17 for detecting the document, a width size detection sensor 28 for detecting the document size, and a first document length sensor. Two
9 and a second document length sensor 30, and a document trailing edge sensor 27 for detecting the trailing edge of the document.

The scanner body includes a scanner body and an AR.
SC for controlling the operation of color image reading device including DF
U7 is installed.

FIG. 2 is an overall block diagram of the image reading apparatus according to the present invention, and FIG. 3 is a flow chart of the image data. Figure 2
The flow of image data in the image reading apparatus of this embodiment will be described with reference to FIG.

The reflected light of the original entering the color CCD on the SBU 10 is converted into an analog signal of each color of RGB having a voltage value according to the intensity of the light in the color CCD. RG
The analog signal of each color B is divided into odd bits and even bits and output. The analog image signal of SBU10 is
The dark potential portion is removed by the analog processing circuit 32 on the VIOB 31, and the odd bit and the even bit are combined,
After the gain is adjusted to a predetermined amplitude, the A / D converter 3
3 is input to be converted into a digital signal. The digitized image signal is subjected to shading correction by the shading ASIC 34, and after the VIPU 31 passes through the SCU 7, image processing such as gamma correction and MTF correction is performed by the RIPU 35, which is an image processing LSI on the SCU 7, and then a synchronization signal and an image clock. Together with this is output as a video signal.

The video signal output from the RIPU 35 is output to the OIPU 36. The video signal output to the OIPU 36 is subjected to predetermined image processing in the OIPU 36, and is input to the SCU 7 again. SCU7 again
The video signal input to is input to the VIDEO input switching circuit 37.

The other input of the VIDEO input switching circuit 37 is a video signal output from the RIPU 35, and the oipu 36 can select whether or not to perform image processing. VIDEO input switching circuit 37
The video signal output from the image data storage means SD
SIBC2, which is a memory control LSI that manages RAM
It is input to (38) and stored in the image memory composed of SDRAM. The image data stored in the image memory is sent to the SCSI controller 39 and transferred to an external device such as a personal computer or a printer.

On the SCU 7, a CPU, RO (not shown)
M and RAM are mounted, and the CPU controls the SCSI controller 36 to communicate with an external device such as a personal computer by SCSII / F. Furthermore, the CPU is VI
The video signal output from the DEO input switching circuit 37 is communicated with an external device such as a personal computer or a printer by a network I / F via an IEEE 1394 controller: ISIC 40 and an IEEE 1394 I / F, and a network scanner controller: NIC 41. The CPU also controls the timing of the traveling body motor 9, which is the stepping motor of the scanner body, and the feed motor (not shown) and the conveyance motor of the ARDF.

The ADU 42 has a function of relaying the power supply of the electrical components used in the ARDF section.

The input port connected to the CPU on the SCU 7 has a main body operation panel: SO via the VIOB 31.
It is connected to P43. Main unit operation panel: SOP43
A start switch and an abort switch (not shown) are mounted on the top. When each switch is pressed, the CPU detects that the switch is turned on via the input port.

A temperature detection sensor such as a thermistor for measuring the temperature of the lamp tube wall is connected to the CPU, and its output is the CPU.
Is input through an internal A / D conversion circuit (not shown).

FIG. 4 is a block diagram relating to the image reading process of the scanner body. Image processing LSI RIPU
To SBU10 which is a CCD drive unit from LSYNC
By outputting (main scanning line synchronization signal) and LGATE (main scanning line data output period), the SBU10
More image data is output. The flow of image data is SB
U10 → RIPU35 → SIBC2 (38) → SCSI
The controller 39 becomes an external personal computer or the like. Also, CP
Image processing LSI (not shown) to turn on / off image output from U
(RIPU35) is equipped in the inside as a known technique, and is controlled by rewriting the internal register. An interrupt signal from the SIBC2 (38) (this interrupt is generated when the memory status is full, near full, or empty, and is a register provided as a known technique inside the memory control LSI (SIBC2) (not shown). C can be distinguished)
It is configured to input to the PU 50. The CPU 50 also controls the traveling body motor 9 for moving the traveling body.

FIG. 5 is a sectional view showing an embodiment in which the reference plate for reading correction is made movable. When the traveling body (first carriage) equipped with the illumination lamp 2 integrally formed with the first mirror 3 is located at an arbitrary position, the white reference plate 51 and the base member 52 having high transparency and refractive index like glass. The sheet is attached so that it is located between the document surface and the first carriage. The white reference plate 51 and the base member 52 having high transparency and high refractive index can be operated in the same direction as the first carriage on a rail parallel to a rail (not shown) on which the first carriage is mounted.

In the present embodiment, the illumination lamp 2 which is the light source.
If the white reference plate 51 moves at the same speed when the traveling body on which is mounted operates, only a certain place of the white reference plate 51 can be read, and it becomes difficult to correct stains fixed at a certain place. The speeds of the two are made different so that either one will move first. This mechanism may be provided with appropriate driving means and control means which are not shown but are known.
Then, it is possible to read different positions of the white reference plate 51, so that the image level correction is stabilized by averaging the areas with and without the stain.

If the moving speed of the white reference plate 51 is slowed down with respect to the moving speed of the traveling body, the moving range of the white reference plate 51 can be reduced to allow a margin for the structure of the machine.

[0026]

As described above, in the image reading apparatus according to the first aspect of the present invention, the traveling body on which the light source is mounted and the reference plate are moved in the same direction at different speeds. It becomes possible to read, and it is possible to read only at a certain place on the reference plate and it is not difficult to correct stains fixed at a certain place, and either one will move ahead due to different speeds. The effect is that stable level correction can be performed by averaging the areas with and without dirt.

As described above, in the image reading apparatus according to the second aspect, the moving speed of the reference plate is slowed relative to the moving speed of the traveling body.
There is an effect that the moving range of the reference plate can be reduced to allow a margin for the machine configuration.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a color image reading apparatus according to the present invention.

FIG. 2 is an overall block diagram of an image reading apparatus according to the present invention.

FIG. 3 is a flow chart of the same image data.

FIG. 4 is a block diagram relating to image reading processing of the scanner body.

FIG. 5 is a cross-sectional view showing an embodiment of a configuration in which a reference plate for reading correction is made movable.

[Explanation of symbols]

1 lens 2 Lighting lamp 3 first mirror 4 third mirror 5 Second mirror 6 DF original glass 8 Platen glass 9 Traveling body motor 17 Platen 51 White reference plate 52 Base member

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 1/04 105 H04N 1/04 103E F term (reference) 2H108 AA01 EA56 HA00 2H109 AA02 CA00 CA34 5B047 AA01 AB04 BA07 BB02 BC09 BC11 BC14 CA08 CB17 DA04 DC06 5C051 AA01 BA03 DA03 DB24 DB28 DC04 DC05 DC07 DE09 DE18 EA01 5C072 AA01 BA13 CA02 DA04 EA05 FB12 LA15 MB02 RA16 UA02 WA02 XA01

Claims (2)

[Claims] 1. A moving body on which a light source is placed moves to illuminate a document at a time and also illuminates a reference plate, and the reflected light of the illuminated document is folded back by a plurality of mirrors to form C.
In an image reading device that reaches a photoelectric conversion element such as a CD and corrects the output of the photoelectric conversion element by using the reflected light of the reference plate as reference reflected light, the reference plate is movably arranged in the same direction as the traveling body. The image reading apparatus is characterized in that the moving speed of the reference plate is different from that of the traveling body. 2. The image reading device according to claim 1, wherein the moving speed of the reference plate is slower than that of the traveling body.