KR19990025759A - Scanner output level deviation compensation circuit - Google Patents

Abstract

The present invention relates to a shuttle scanner-type multifunctional apparatus capable of compensating for a deviation of an output level in a scanner module.

A lens for focusing light reflected on the original surface of the lamp, a lens for focusing the reflected light on the original surface of the lamp, And an analog / digital converter (ADC) for correcting the deviation of the output level of the sensor, the scanning device comprising: The comparative power of the analog / digital converter (ADC) can be changed to an appropriate level according to the actual signal width, so that the effect can be obtained by one adjustment in the production of the product.

Description

Scanner output level deviation compensation circuit

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a shuttle scanner type MFP, and more particularly, to a compensation device for a deviation of an output level in a scanner module.

Generally, computers, printers, copiers, scanners and fax machines used in offices are also called office machines. These office machines have unique functions for each machine.

The printer is a typical output device for outputting a file such as a document created by a computer in the form of characters on a document. A copying machine is a device for forming a document or other type of image on a document as it is. It is very useful for mass copying of the same image.

On the other hand, the scanner has many similarities with the copying machine and the driving method. Except that the output format of the scanned image appears as a data file.

In this way, office equipment maintains a different independent form in order to implement each function.

Recently, a product has been emerging for displaying the functions of each office equipment in a complex manner. Among these, a multifunction apparatus capable of implementing functions of an inkjet printer, a scanner, and a facsimile will be described.

Fig. 1 shows a schematic system configuration of this multifunction apparatus. The CPU 1 controls the entire system and controls the system memory 6 in which a program for driving the entire system is embedded.

The image processing section 2 is controlled by the CPU 1 to perform shading and gamma correction of the image data input from the shuttle scanner module 3 and DPI conversion, Edge emphasis, and Error Diffusion.

According to the control of the CPU 1, the modem unit 9 performs facsimile transmission of the processed image data, and printing at the PC at the time of printing or fax reception is performed by the ECP 7-1.

The shuttle scanner module 3 performs a shuttle scanning method as a portion for reading image data.

The rasterizer 4 is a part for rasterizing the image data read by the vertical block.

The image memory 5 is a buffer memory for processing image data necessary for image processing in the image processing unit 2. [

The system memory 6 is composed of an EPROM having a built-in system program and an SRAM for system data processing.

ECP (7-1) is a module for direct parallel interface with PC. It is a part for sending scanned data to PC and receiving data to be printed on PC.

The printer driver 7-2 performs necessary printhead ejection control, driving control of the carriage motor and line feed motor, and printing data handling for printing.

The overall structure of such a system can be represented as shown in FIG.

The scanner module 3 and the ink cartridge module 13 move along the same horizontal movement shaft 14. [ Therefore, it is driven by using the moving belt 12 and the carriage return motor 11.

The original 100 is fed and discharged by the line feed roller 16 rotated by the driving of the line feed motor 15. [

3 is a side view showing a scanning process during operation of the multifunction apparatus, focusing on a scanner module. Such a shuttle scanning device can be constructed with the inkjet head module and use the same driving system.

The scanner module 3 and the ink cartridge module 13 restrained by the moving belt 12 are reciprocated left and right along the original surface by rotational drive of the carriage return motor 11. [ And a method of reading and printing images by this driving is used.

The document 100 housed in the paper cassette 40 is drawn between the drive roller 41 and the pinch roller 42 by the paper feed roller 45. [ After the scanning process of the scanner module 3 is completed, is discharged by the rotational force of the discharge roller 43 and the pinch roller 44. [

The printing function is to transfer the ink of the ink jet head of the cartridge module 13 to the original 100 while the scanner module 3 and the ink cartridge module 13 move left and right.

The scanning function irradiates the original 100 with light by the lamp 31 in the scanner module 3 while the scanner module 3 and the cartridge module 13 move left and right.

The configuration will be described with reference to FIG. FIG. 4A is a cross-sectional view of such an optical imaging system, and FIG. 4B is a side view of an optical imaging system. A lamp 31 that transmits light energy to the original 100 and a lens that focuses the reflected light when the light generated from the lamp 31 is reflected on the original 100 to the CCD 34 And a CCD 34 for converting the light energy into a voltage in the form of electrical energy and outputting the voltage to recognize an image.

Here, the CCD (Charge Coupled Device) 34 is a sensor for converting light energy into a voltage which is an electrical energy.

The operation principle will be described with reference to FIG. The amount of light reflected on the original surface 100, that is, the image data of the original surface is focused on the sensing surface of the CCD sensor 34 while being transmitted through the lens 33 and reaches the sensing surface of the CCD sensor 34 to read the image data.

The image signal detected by the CCD sensor is transmitted to an analog-to-digital converter (ADC). The analog signal input to the ADC converts the input signal into a digital signal according to the number of ADC bits (bits) at the fixed reference voltage of the ADC. In this case, the fixed reference voltage is divided into a white reference voltage + V _REF and a black reference voltage -V _REF .

For an 8-bit ADC, depending on the ADC, divide the + V _REF to -V _REF by 256 steps and convert the signal input to the ADC to the corresponding digital value. Based on this value, a shading compensation value is calculated to compensate the corresponding pixel data.

As described above, in the shuttle scanning type MFP in which the ADC reference voltages (+ V _REF , -V _REF ) are fixed, there is no way to compensate when a low level image outside the shading region is input.

Take, for example, the case where the ADC can compensate for twice the value input to the image processor in the normal case. If a signal (C) of 127 or less is input based on the 8Bit ADC due to deviation of the sensor, deviation of the lamp, or deviation of other optical system, the white data does not become 255 even if the shading compensation limit is doubled.

When the 128 level signal is shaded to the 255 value, all the values are amplified twice, and the 128 levels of the input signal are obtained.

When the result of scanning the white reference is as shown in FIG. 6, the output of the image sensor is implemented up to 255 steps in the case of A and B. However, since the white level of C is less than ½V _REF , 255 is not generated even if the shading compensation is performed. Therefore, white data does not appear in white.

In order to solve such a problem, the present invention aims to vary a comparison voltage when the input signal transmitted through an optical sensor is smaller than a design value, and correct the deviation of the optical system by adjusting the ratio to the design value.

According to an aspect of the present invention, there is provided a projection exposure apparatus including a lamp for emitting light energy to an original surface according to an applied power source, a lens for focusing reflected light when the light generated from the lamp is reflected on the original surface, A sensor configured to detect an image by converting the energy of reflected light transmitted through the lens into an electrical energy form and an analog / digital converter (ADC) for correcting a deviation in the output level of the sensor; 1. A scanning apparatus having an imaging system, the scanning apparatus comprising: The comparative power of the analog / digital converter (ADC) can be changed to an appropriate level according to the actual signal width.

1 is a block diagram showing a configuration of a general MFP;

Fig. 2 is an exemplary view showing the structure of the system of Fig. 1 from a mechanical perspective,

FIG. 3 is a side view showing the scanner module in operation of the multifunction apparatus,

4 is a sectional view showing a configuration of a scanner module,

5 is an operational state diagram showing the operation principle of the scanning apparatus,

6 is a graph showing a correlation between ADC input signals and comparison voltages according to the related art,

FIG. 7 is a block diagram for performing a scanner function according to the present invention;

8 is a graph showing a correlation between ADC input signals and comparison voltages according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings.

7 is a detailed block diagram of a scanner according to the present invention. The scanner driver 300 outputs a control signal for recognizing the document through the scanner module 3. [ When the scanning is performed, the image of the white reference reflected on the light source of the lamp is converted into a signal by the scanner and applied to the ADC 200. The image processing unit 2 transfers the image data to the image storage device 5 via the data bus in accordance with the control signal of the scanner driver 300. [

The input image signal is converted into an 8-bit digital signal by the ADC 200. At this time, the reference voltage is used. At this time, the signal from the sensor to the ADC and the ADC reference voltage are checked. At this time, when the lamp is smaller than the design value, that is, when the lamp light source is low, when there is a deviation in the lens or sensor filter, or when the distance between the sensor module and the white reference is large, an output level below the expected value occurs.

The + V _REF value can be varied to match the design value. After this set adjustment, the ADC input signal is converted to a digital value that translates between the modified + V _REF adjustment and -V _REF in 256 steps.

As shown in FIG. 8, when the ADC input signal B is smaller than the design value A, + V _{REF changes} as the + V _REF adjustment value. Therefore, it is possible to reduce the gradation loss by correcting the deviations of the set by adjusting the same ratio as the design value.

As described above, it is possible to obtain the effect of one adjustment in the production of the product.

Claims (2)

A lamp for injecting light energy onto the original surface according to an applied electric power source, A lens for focusing the reflected light when the light generated from the lamp is reflected on the original surface, A sensor for converting an energy of reflected light transmitted through the lens into an electric energy form to recognize an image, And an analog / digital converter (ADC) for correcting a deviation of an output level of the sensor, the scanning apparatus comprising: Wherein the comparison power source of the analog / digital converter (ADC) is changed to an appropriate level according to a width of an actual signal. The multifunctional apparatus according to claim 1, wherein the comparison power source of the analog / digital converter is divided into 1024 steps between + V _REF and -V _REF .