JP2002281325A - Color image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To replace pieces of image data of R/B by simple structure in a color image reader to read the image data by an RGB three-line linear sensor. SOLUTION: In the color image reader capable of performing a signal processing of the image data read by the RGB three-line linear sensor, a function to replace pieces of the image data of R/B is provided to an ASIC to perform signal processing of a CCD, a motor, a lamp driving signal and the image data as an internal function and pieces of the image data of R/B are replaced by the function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image reading apparatus, and more particularly to a digital color copier and a color facsimile apparatus equipped with an automatic document feeder (ADF).

[0002]

2. Description of the Related Art As a color image reading apparatus, there is an automatic document feeder (ADF) above a scanner section of a color copying machine. The automatic feeder feeds multiple documents one by one onto the scanner's contact glass, and the scanner uses the R (red), G (green), and B (blue) three-line linear sensor to image the document. When reading a document automatically conveyed by the ADF (Auto Document Feeder) by the R, G, B 3 line linear sensor that reads data, the R, G, B 3 line If the position is reversed, the beginning of the R, G, B delay is R
Switch with / B. Therefore, it is necessary to exchange R / B image data. At that time, since the positional relationship between the original and the three-line linear sensor is reversed, it is necessary to correct the distance between the R and B lines. Therefore, conventionally, this correction is performed by converting the R, G, and B image data into a dedicated ASIC (Application Specific Integrated Circuit).
uit) and correction between lines is performed by switching the correction mode by setting the CPU and the register. Its registers are field memory and FIFO (First In First Out)
The correction was performed using the memory.

FIG. 4 is a block diagram of a conventional signal processing block. The reading positions of the RGB line sensors are physically different from each other by the distance between the RGB line sensors on the CCD 11. Conventionally, the control A
The difference between the RGB lines was corrected by the field memory delay circuit of the preceding block in the SIC 13. Control ASIC
Reference numeral 13 denotes an ASIC for performing various controls such as lamp lighting control, motor drive control, CCD drive control, and various sensors (home position sensors).

[0004]

As described above, in the conventional apparatus, since the correction is performed using the FIFO memory via the CPU for the control ASIC, the load on the CPU is large, and the signal processing at the next stage is also performed. There is a problem that the circuit unit needs to be changed.
Therefore, a first object of the present invention is to provide the correction means which has solved the conventional problems. A second object of the present invention is to replace the signal of the CCD line sensor with an analog signal so that the next stage of signal processing can be performed. A third object of the present invention is to reduce the internal functions of the control signal processing ASIC, thereby reducing the number of pins of the ASIC, thereby reducing the cost.

[0005]

According to a first aspect of the present invention, a CCD, a motor, a lamp drive signal and image data are signal-processed.
By providing a mode for exchanging R / B image data for ADF as an internal function of the ASIC, digital image data can be used as is in the next-stage image processing (shading correction, dot correction, scanner gamma correction, etc.) ASIC In a color image reading device capable of signal processing of image data read by an RGB three-line linear sensor by inputting, an image having a mode for exchanging R / B image data read from a CCD line sensor as an internal function. A color image reading device having a data processing ASIC.

According to a second aspect of the present invention, the signal of the CCD line sensor before the input of the R / B image data is input to the signal processing IC is exchanged by an analog switch.
An analog signal read from a CCD line sensor in a color image reading apparatus capable of performing signal processing of image data read by an RGB three-line linear sensor by replacing the analog signal and performing signal processing of the next stage. A color image reading apparatus having an analog switch for exchanging R / B image data.

According to a third aspect of the present invention, the replacement of R / B image data is set in a programmable manner so that the R / B can be switched between the transmitting side and the receiving side during the function of LVDS (Low Voltage Differential Signaling). And R
In a color image reading device capable of signal processing of image data read by a GB3 line linear sensor, a program can be set so that R / B image data read from a CCD line sensor can be exchanged between a transmitting side and a receiving side.
A color image reading device having LVDS.

[0008]

Embodiments of the present invention will be described below. The digital color copying machine is composed of a scanner, a printer, and an automatic document feeder (ADF). The operation is as follows. That is, after setting copy conditions by key operation of the operation unit, a document is set on the contact glass of the scanner, and when the start is pressed, the main control unit starts controlling the copy operation.

When the ADF has a plurality of originals, the originals are fed one by one onto a contact glass by a feed roller.
Further, the sheet is conveyed to the reading position on the contact glass by the conveying belt and set. When the document is set at the reading position, the scanning operation starts. That is, when the start of the scanning operation is instructed, the carriage integrated with the lamp and the first mirror reciprocates in the horizontal direction, thereby scanning the image. The reflected light from the document surface is reflected by the second mirror,
The light is guided to the lens via the third mirror and forms an image on the light receiving surface of the color line linear sensor. The color line linear sensor is a sensor that converts optical image signals of three colors R, G, and B of the image forming light beam into electric signals.

The converted R, G, B image signals are clamped at a black level in an optical black pixel area by a signal processing section, amplified by a gain amplifier, and then subjected to A / D conversion before shading correction. , Γ correction, dot correction circuit, etc., the signal is processed.

By the way, an ADF (Auto Document Fee) which automatically conveys a document to the above-described color image reading apparatus, that is, a color image reading apparatus capable of processing image data read by an RGB three-line linear sensor.
der), the position of the RGB 3-line linear sensor may be reversed with respect to the top of the original when reading in the Book / ADF mode.
It is necessary to switch by R / B. Since G is in the middle of the line sensor and does not change, the R / B image data is replaced or correction between RGB lines is performed. The present invention provides means for replacement like R / B image data, and the means will be described.

FIG. 1 shows one embodiment of the invention according to claim 1, and is a block diagram in which a signal processing for R / B exchange is performed by a control ASIC. Here RG
The 10-bit digital output of the A / D converter, which is the B image signal, is sent to the control ASIC 13 for each of R, G, and B signals.
It is configured to input 0 bits at a time and exchange R / B in the ASIC 13.

FIG. 2 shows an embodiment of the second aspect of the present invention, and is a block diagram of signal processing by an analog switch. As shown, the R and G signals from the CCD 11 are directly exchanged by an analog switch 20 connected to the next stage of the CCD. The exchanged signals are input to the respective signal processing circuits 12 and subjected to the above-described processing.

FIG. 3 shows an embodiment of the third aspect of the present invention, in which an LVDS (Low Voltage Differential) is used.
FIG. 2 is a block diagram of an R / B exchange signal processing according to Signaling). When transmitting the image information signal in the scanner unit to the signal processing unit of the printer unit via LVDS,
DS has the advantage of being a small-amplitude differential signal and strong against noise, so using LVDS, its internal function is programmable,
That is, the R / B is exchanged between the transmission side and the reception side in the program setting and transmitted.

[0015]

According to the first aspect of the present invention, there is no need to use a FIFO memory via the CPU for the control ASIC, so the load on the CPU is reduced. There is no need to change the next-stage signal processing circuit.

According to the second aspect of the present invention, since the signal is switched to R / B by the analog switch, the CCD output can be directly input to the next signal processing circuit.

[0017] The effect corresponding to claim 3: R / B by LVDS
To control the internal functions of the control ASIC,
The next signal processing can be performed without the intervention of the CPU. In addition, ASI is no longer required to route signal lines to ASICs or CPUs.
The number of C pins is reduced, and there is an advantage in cost.

[Brief description of the drawings]

FIG. 1 is a block diagram of an inter-line correction signal processing block according to an embodiment of the present invention;

FIG. 2 is a block diagram of an inter-line correction signal processing block according to an embodiment of the present invention;

FIG. 3 is a block diagram of an inter-line correction signal processing block according to an embodiment of the present invention;

FIG. 4 is a block diagram of a conventional signal-to-line correction signal processing block.

[Explanation of symbols]

11 ... CCD, 12 ... R, G, B signal processing circuit, 13 ...
ASIC for control, 20 ... Analog switch, 30 ... LV
DS (transmitting side), 31 ... LVDS (receiving side).

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Claims (3)

[Claims] 1. A color image reading apparatus capable of performing signal processing on image data read by an RGB three-line linear sensor, comprising: a mode for exchanging R / B image data read from a CCD line sensor as an internal function thereof. A color image reading device having a ASIC for use. 2. A color image reading apparatus capable of processing image data read by an RGB three-line linear sensor, comprising an analog switch for exchanging R / B image data of an analog signal read from a CCD line sensor. Color image reading device. 3. A color image reading apparatus capable of signal processing of image data read by an RGB three-line linear sensor, wherein a program is provided so that R / B image data read from a CCD line sensor can be exchanged between a transmission side and a reception side. A color image reading device having a settable LVDS.