JP3151729B2 - Image reading device and image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to an image reading apparatus and <br/> image forming apparatus, and that equipment be especially chromatic <br/> gradation processing function.

[0002]

2. Description of the Related Art At present, various image processing functions of a digital copying machine are used as useful functions particularly in design-related work. In the printing of catalogs, pamphlets, posters, and the like, there is a "gradation" as a method aiming at a special effect. This is a method of forming an image by gradually changing the density of the image from one end of the image to one end of the other, gradually or densely.

[0003]

Conventionally, when trying to obtain a finished image of an image that has been subjected to "gradation" processing prior to underlay work such as printing, the target document is changed in output density to obtain an image. Sheets were copied, an appropriate portion was cut out from each of the copied sheets, and further, such operations as bonding were performed. These operations required a great deal of labor.

An object of the present invention is to provide an image reading apparatus for reading an image of a document and performing "gradation" processing.
Graduation by reading the image of the original
It is an object of the present invention to provide an image forming apparatus that performs processing and records on a sheet .

[0005]

An image reading apparatus according to the present invention scans a document in a main scanning direction and a sub-scanning direction, and reads image data, a line synchronization signal, and a pixel clock for each read pixel.
Image reading means (100,1～ 8, 101-105) for outputting a click; first storage unit (206) and a second storage unit (207); a multiplier for each sub-scanning address in the first storage unit (206) Write
And writes the multiplier for each main scanning address in the second storage unit (207) .
A multiplier setting means (107) for counting the line synchronization signal and first storing the sub-scanning address
A sub-scanning counter (204) to be provided to the section (206); counts a pixel clock and stores a main scanning address in a second storage section
Main scanning counter (205) to be given to (207); multiplier output from first storage unit (206) and second storage unit (207)
Multiplying means for multiplying the image data by the multiplier output by
03); and an instruction means for instructing the processing mode of the image data (311, 312); provided with, the multiplier setting means (107), the finger
When there is a gradation instruction by the indicating means (311, 312) ,
Image density at least one per scan line and per pixel
First and second storage unit a multiplier for may sequentially varying the (206,2
Write to 07). The symbols in parentheses are corresponding elements in the embodiments described later.

[0006]

SUMMARY OF According to this, the number of setting means multiplication (107), if there is a gradation indicated by the indication means (311, 312), at least one image density for each scanning line and for each pixel sequentially <br/> following first and second storage unit a multiplier for can-varying (206, 207)
Write to. Therefore, in this setting state, when performing image reading of the document by the image reading apparatus <br/>, the sub-scanning direction and
Image data in which the image density gradually increases or slightly changes in at least one of the main scanning directions can be formed.

Further, in a preferred embodiment of the image reading apparatus of the present invention, the multiplier setting unit (107), when there is more gradations continuous shooting instruction to the instruction means (311, 312),
From the top in the sub-scanning direction of the original to be read first among multiple originals
The first and the multiplier for may sequentially varying the concentration scan lines each through to the sub-scanning direction of the tail of the document to be read last
Writing to the second storage unit (206, 207) . Therefore, the multi-sheet
Scan the original to be scanned first from the top in the sub-scanning direction to the last.
Through to the sub-scanning direction of the tail of the document to take, it is possible to form an image data changing concentration gradually thicker or thinner.

The preferred embodiment of the image reading apparatus of the present invention further comprises means (307, 308, 30) for designating an image area.
9,310) ; wherein the multiplier setting means (107) includes first and second multipliers.
And addresses in the designated area of the second storage unit (206, 207).
Is an image for at least one of each scan line and each pixel.
Specify a multiplier for sequentially changing the density at an address outside the specified area.
Is written with a multiplier for no image. Therefore, there is gradation only for the specified area
Image data representing the image is formed, and there is no image outside the specified area.
Since the image data is formed , the work corresponding to the cutting and pasting can be easily performed by the image data as in the related art.

An image forming apparatus according to the present invention scans an original in a main scanning direction and a sub-scanning direction and scans an image for each read pixel.
Data, the image reading means (100,1～ 8, 101-105) for outputting a line synchronization signal and a pixel clock; the first storage unit (206); the first storage unit (206) and a second storage unit (207) Write multiplier for each sub-scan address
And writes the multiplier for each main scanning address in the second storage unit (207).
A multiplier setting means (107) for counting the line synchronization signal and first storing the sub-scanning address
A sub-scanning counter (204) to be provided to the section (206); counts a pixel clock and stores a main scanning address in a second storage section
Main scanning counter (205) to be given to (207); multiplier output from first storage unit (206) and second storage unit (207)
Multiplying means for multiplying the image data by the multiplier output by
03); instruction means (311, 31 ) for instructing the processing mode of the image data
2); and print the image represented by the product of the multiplier and the image data
An image forming means (A) for forming thereon , and the multiplier setting means (107) includes an instruction means (311, 312).
If there is a gradation indicated by, Oyo scanning lines per
At least one of each micro-pixel for may sequentially varying the image density
Is written into the first and second storage units (206, 207).

[0010]

SUMMARY OF According to this, the number of setting means multiplication (107), if there is a gradation indicated by the indication means (311, 312), at least one image density for each scanning line and for each pixel sequentially <br/> following first and second storage unit a multiplier for can-varying (206, 207)
Write to. Therefore, in this setting state, the image reading device
In performs image reading of the document, when the image forming process is performed by the image forming means (A), the sub-scanning direction and the main scanning direction
It is possible to form an image at least one image density changes gradually thicker or thinner.

In a preferred embodiment of the image forming apparatus according to the present invention, the multiplier setting means (107) includes an instruction means.
If there is more gradations continuous shooting instruction to the (311, 312), the outermost from the head in the sub-scanning direction of the document to be read first in the multi-sheet
A multiplier for may sequentially varying concentrations for each scanning line through to the sub-scanning direction tail of document to be read after the first and second
2 Write to the storage units (206, 207) . Therefore, the maximum
Scan the original to be scanned first from the top in the sub-scanning direction to the end
That through until the sub-scanning direction of the tail of the document, it is possible to form an image which changes the concentration gradually thicker or thinner.

The preferred embodiment of the image forming apparatus according to the present invention further comprises means for specifying an image area (307, 308, 309, 3).
10) ; wherein the multiplier setting means (107) includes first and second multipliers .
2 The address in the designated area of the storage unit (206, 207) is
At least one of the image density for each inspection line and each pixel
The multiplier for sequentially changing the addresses outside the specified area
Write the multiplier to eliminate the image. Therefore, an image with gradation is displayed only for the specified area.
Image data is formed, and there is no image outside the specified area
Since an image is formed , cut and paste as before
Yellow, cut of the image is Ru easy der.

As described above, according to the present invention, in the sub-scanning direction
And since at least one image density in the main scanning direction gradually thicker or thinner "Gradient" is easily to change the copy having different concentrations as in the prior art with a plurality prepared, cumbersome work such cutting and pasting Is not required. Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0014]

FIG. 1 shows a main body mechanism according to an embodiment of the present invention. This is a digital copying machine, and its mechanism is composed of four units: a copying machine main body A, an automatic document feeder (ADF) B, a sorter C, and a duplex reversing unit D. The copying machine main body A includes a scanner unit, a writing unit, a photoconductor unit, a developing unit, a paper feeding unit, and the like. Next, the configuration and operation of each unit will be described.

(1) Scanner unit The first scanner which is equipped with a reflecting mirror 1, a light source 3 and a first mirror 2 and moves at a constant speed, and the second mirror 4 and a third mirror 5 which are equipped with the first mirror A second scanner that moves following the first scanner at half the speed of the scanner;
An original (not shown) on the contact glass 9 is optically scanned by the first scanner and the second scanner, and the reflected image is guided to the lens 7 via the color filter 6 and formed on the one-dimensional solid-state imaging device 8. Image.

As the light source 3, a fluorescent lamp, a halogen lamp, or the like is used, and a fluorescent lamp is generally used because its wavelength is stable and its life is long. In this embodiment, the reflecting mirror 1 is attached to one light source 3, but two or more light sources may be used. Since the solid-state imaging device 8 has a fixed sampling clock, the fluorescent lamp has an adverse effect on the image unless it is turned on at a higher frequency.

As the solid-state imaging device 8, generally, C
CDs are used. The solid-state imaging device (CCD) 8
Since the image signal read in step (1) is an analog value, the image signal is converted from analog to digital (A / D), and various image processing (binary, multi-level, gradation, scaling, editing) is performed on the image processing board 10. Processing) and converted into a digital signal as a set of spots.

In order to obtain color image information, in the present embodiment, a color filter 6 that transmits only necessary color information is disposed in the optical path guided from the original to the solid-state image pickup device 8 so as to be able to enter and exit. The color filter 6 is moved in and out in accordance with the scanning of the original, and each time a function such as multiple transfer or double-sided copy is operated, various kinds of copies can be created.

(2) Writing Unit The image information after the image processing is written on the photosensitive drum 40 in the form of a set of light points by raster scanning of laser light in an optical writing unit.

As a laser light source, a He-Ne laser has been used. The wavelength of this He-Ne laser is 633.
In nm, have been used to fit well with the sensitivity of the copying machine the photoreceptor past, and it laser light source itself is very expensive, the problems such apparatus because it can not directly modulated complicated Have. In recent years, semiconductor lasers that are inexpensive and capable of direct modulation have been used due to high sensitivity in the long wavelength region of photoconductors. This embodiment also uses this semiconductor laser.

FIG. 2 is a plan view showing the writing section.
The laser light emitted from the semiconductor laser 20 is changed into a parallel light beam by the collimator lens 21, and is shaped into a light beam of a predetermined shape by the aperture 32. The shaped laser beam enters the polygon mirror 24 in a form compressed by the first cylinder lens 22 in the sub-scanning direction. The polygon mirror 24 has an accurate polygon, and is rotated by a polygon motor 25 at a constant speed in a constant direction. This rotation speed is determined by the rotation speed of the photosensitive drum 40, the writing density, and the number of surfaces of the polygon mirror 24.

The reflected laser light incident on the polygon mirror 24 is deflected by the rotation of the polygon mirror 24. The deflected laser light is applied to the fθ lenses 26a and 26a.
b, 26c. fθ lenses 26a, 26
b, 26c are scanning light beams having a constant angular velocity
Is converted to scan at a constant speed on the photosensitive drum 40
An image is formed so as to have a minimum light spot on the top, and a surface tilt correction mechanism is also provided.

The laser light passing through the fθ lenses 26a, 26b and 26c is guided to the synchronization detection light input section 30 by the synchronization detection mirror 29 outside the image area, propagated to the sensor section by an optical fiber, and searched for in the main scanning direction. The synchronization detection is performed as a reference for and the synchronization signal is output. One line of image data is output after a certain period of time from the output of the synchronizing signal. By repeating this operation, one image is formed.

(3) Photosensitive Member A photosensitive layer is formed on the peripheral surface of the photosensitive drum 40. As a photosensitive layer sensitive to a semiconductor laser (wavelength 780 nm), a structured photoconductor (OPC), α-Si, Se-Te, and the like are known. In the present embodiment, a structured photoconductor (OPC) is used. are doing. In general, in the case of laser writing, there are two types of processes: a negative / positive (N / P) process for applying light to an image portion and a positive / positive (P / P) process for applying light to a background portion. A negative / positive (N / P) process is employed.

The charging charger 41 is of a scorotron type having a grid on the photoconductor side.
The surface of No. 0 is uniformly (-) charged, and the image forming portion is irradiated with laser light to lower the potential of that portion. Then, the background portion of the surface of the photosensitive drum 40 is -750 to -800 V, and the image portion is-
The potential becomes about 500, and an electrostatic latent image is formed on the surface of the photosensitive drum 40. This is applied with a bias voltage of -500 to -600 V to the developing roller by the developing devices 42a and 42b,
The electrostatic latent image is visualized by attaching the charged toner to (−).

(4) Developing Unit The apparatus of this embodiment has two developing units, a main developing unit 42a and a sub developing unit 42b. In the case of a single black color, the sub-developing device 42b and the toner replenishing device 43b are detached. In this embodiment having two developing units, the main developing unit 42a
The black toner is put into the toner supply unit 43a paired with the sub-developing unit 42b, and the color toner is put into the toner supply unit 43b paired with the sub-developing unit 42b. And selectively develop.

Using this development, the color filter 6 of the scanner is used.
The color information can be read by switching the color information, and the multi-transfer and double-side copy functions of the paper transport system can be combined to perform multifunctional color copy and color editing. The development of three or more colors can be achieved by a method of arranging three or more developing devices around the photosensitive drum 40, a revolver method of rotating and switching the three or more developing devices, or the like.

The images visualized by the developing units 42a and 42b are transferred to the paper surface synchronized with the photosensitive drum 40 by applying (+) charge from the back surface of the paper by the transfer charger 44. You. The transferred paper is discharged from the photosensitive drum 40 by an AC charge removal by a separation charger 45 held integrally with the transfer charger 44. The toner remaining on the photoconductor drum 40 without being transferred to the paper is scraped off from the photoconductor drum 40 by the cleaning blade 47 and collected in an attached tank 48. Further, the pattern of the potential remaining on the photosensitive drum 40 is erased by irradiating light with the charge removing lamp 49.

A photo sensor 50 is provided immediately after the development. This photo sensor 50
Is composed of a pair of a light emitting element and a light receiving element, and detects the reflection density on the surface of the photosensitive drum 40. In this method, a certain pattern (for example, a black pattern or a halftone dot pattern) is written in a position corresponding to a reading position of a photo sensor by an optical writing unit, and after the development, the reflectance of the pattern unit and the photoconductor other than the pattern unit are developed. The image density is determined from the ratio of the reflectance of the drum 40. If the image density is low, a toner supply signal is output. In addition, the fact that the density does not increase even after replenishment can be used to detect the lack of the remaining amount of toner.

(5) Paper Feeding Unit In this embodiment, a plurality of cassettes 60a, 60b, and 60c are provided, and paper once transferred is passed through a re-feeding loop 72 so that double-sided copying or re-feeding is possible. .

When a start button is pressed after one of the cassettes 60a, 60b, 60c is selected, the sheet feed rollers 61 (61a, 61b, 61c) near the selected cassette are pressed. Are fed until the leading edge of the paper hits the registration roller 62. Although the registration roller 62 is stopped at this time, the registration roller 62 starts rotating at a timing corresponding to the image position formed on the photosensitive drum 40 and feeds the paper to the peripheral surface of the photosensitive drum 40. Thereafter, the paper is transferred to a toner image at a transfer unit, is suction-conveyed by a separation conveyance unit 63, and the toner image transferred by a fixing roller including a pair of a heat roller 64 and a pressure roller 65 is fixed on the paper surface. I do.

At the time of normal copying, the paper transferred in this manner is guided to the paper discharge port on the sorter C side by the switching claw 67. On the other hand, at the time of multiple copying, the direction is changed by the switching claws 68 and 69 and the sheet is guided to the registration roller 62 again through the lower sheet re-feeding loop 72 without being discharged to the sorter C side.

In the case of double-sided copying, there are two cases, one in which the copying machine body A alone is used and the other in which the double-sided reversing unit D is used. Here, the former case will be described. The paper guided downward by the switching claw 67 is further guided downward by the switching claw 68, and is guided by the next switching claw 69 to the tray 70 further below the sheet re-feeding loop 72. The sheet is fed again in the reverse direction by the reversal of the roller 71, and is guided to the re-feeding loop 72 by the switching of the switching claw 69, and is fed to the registration roller 62.

The automatic document feeder (ADF) B will be described. The automatic document feeder (ADF) B automatically guides documents one by one onto the contact glass 9 and automatically discharges them after copying. Document feeder table 100
Are placed in the width direction of the original by the side guide 101. The placed document is fed by the feed roller 10
In step 4, the paper is separated and fed one by one, transported to a predetermined position on the contact glass 9 by the rotation of the conveyor belt 102, and positioned. When the predetermined number of copies have been completed, the original is discharged onto the discharge tray 103 by the rotation of the transport belt 102 again. The document size can be detected by counting the position of the side guide 101 and the document feeding time.

The sorter C will be described. This sorter C
Indicates that the copy paper discharged from the copier main body A is to be stored in, for example, a page order, page by page, or a bin 111 set in advance.
a to 111x. Motor 1
Copy paper fed by a plurality of rollers rotated by 10 is guided to a selected bin 111 by switching a claw near the entrance of each bin 111.

The duplex reversing unit D will be described. As described above, the copying machine main body A can perform only double-sided copying for each sheet. However, by providing the double-sided reversing unit D, double-sided copying can be performed collectively. When making a double-sided copy of a plurality of sheets, the paper guided downward by the paper discharge rollers 66 is sent to the double-sided reversing unit D by the next switching claw 67. The paper that has entered the double-sided reversing unit D is stacked on the tray 123 by the paper discharge rollers 120. At this time, the length and width of the copy paper are aligned by the feed roller 121 and the side alignment guide 122. The copy sheets stacked on the tray 123 are re-supplied by the re-feed roller 124 during backside copying. At this time, the refeeding loop 7 is directly
It is led to 2. In FIG. 1, 27 is a mirror, 28
Is a dust-proof glass, 31 is a lens holding unit, 46 is a separation claw, 80 is a main motor, and 81 is a fan motor.

Next, a description will be given of an electrical control unit for controlling the components described above.

FIGS. 3 and 4 are block diagrams of the electrical control section of the entire copying machine. Both figures are obtained by dividing one block diagram, and are partially overlapped with the central processing unit CPU (a). If these figures are connected at that part, it becomes a whole block diagram.

The control unit of the copying machine has two CPUs.
(A) and (b). The CPU (a) controls the sequence and the CPU (b) controls the operation. The two are connected by a serial interface (RS232C).

First, the control of the sequence relation will be described. The sequence sets and outputs the conditions for paper conveyance timing and image formation.
Sensors related to paper conveyance such as paper ejection detection and registration detection, duplex unit, high voltage power supply unit, relay, solenoid,
A driver such as a motor, a sorter unit, a laser beam scanner (writing) unit, and the like are connected.

In terms of sensors, a paper size sensor that detects the size and orientation of the paper loaded in the paper feed cassette and outputs an electric signal according to the detection result, a sensor related to paper conveyance such as registration detection and discharge detection, an oil end, There are inputs from sensors that detect the presence or absence of supplies such as toner end, and sensors that detect mechanical errors such as door open and fuse blow.

In the double-sided unit, a motor for adjusting the paper width, a paper feed clutch, a solenoid for changing the conveyance path, a paper presence / absence detection sensor, a side fence home position sensor for adjusting the paper width, and a paper conveyance And other sensors.

The high-voltage power supply unit applies predetermined high-voltage power to the outputs of the charging charger, the transfer charger, the separation charger, and the developing bias electrode by the duty obtained by the PWM control.

The driver includes a paper feed clutch, a registration clutch, a counter, a motor, a toner supply solenoid, a power relay, a fixing heater, and the like.

The sorter unit is connected by a serial interface, and conveys the paper at a predetermined timing according to a signal from the sequence and discharges the paper to each bin.

The analog inputs include a fixing temperature, a photo sensor input, a laser diode monitor input, a laser diode reference voltage, and feedback values of output values from various high voltage power supplies. On / off control or phase control of the heater is performed so that the temperature of the fixing unit becomes constant by an input from a thermistor in the fixing unit. As for the photo sensor input, a photo pattern formed at a predetermined timing is input by a photo transistor and the density of the pattern is detected to control the toner supply clutch on / off to control the toner density. As a mechanism for adjusting the power of the laser diode to be constant, an A / D converter and an analog input of the sequence CPU (a) are used. This is controlled so that the monitor voltage when the laser diode is turned on matches a preset reference voltage (this voltage is set so that the laser diode becomes 3 mW in this embodiment).

The image control circuit (c) generates timing signals such as masking, trimming, erasing, and photosensor patterns, and sends out a video signal (VDATA) to the laser beam scanner unit. The laser beam scanner unit receives the input video signal (VDA
TA), the signal is converted into an analog signal again by performing pulse width modulation, and a laser diode is turned on by the modulated pulse, thereby forming an electrostatic latent image of one pixel multi-gradation on the photosensitive member.

The gate array transmits an image signal from the scanner to a synchronization signal PMSY from the laser beam scanner unit.
The signal is synchronized with the NC and further converted into a signal (ODATA) synchronized with the image writing signal RGATE and output to the image control circuit (c).

Next, the control of the operation relation will be described. The main CPU (b) controls a plurality of serial ports and a calendar IC. An operation unit, a scanner control circuit (reading unit), a facsimile, an interface unit, and the like are connected to the plurality of serial ports in addition to the sequence CPU (a).

The operation unit has a display for displaying the key input of the operator and the state of the copying machine. The key input information is transmitted serially to the main CPU (b), and the display is displayed by the serial reception from the main CPU. Light. What is a scanner?
Information regarding image processing and image reading is transmitted serially, and predetermined information contents are exchanged with the facsimile and the interface unit. Calendar IC
Stores the date and time and can be called at any time by the main CPU (b). By displaying the current time on the operation unit display and setting the on / off time of the machine, the power of the machine is turned on / off. Can be controlled by a timer.

FIG. 5 is a block diagram of the image scanner unit. The scanner control circuit 460 controls the lamp control circuit 458, the timing control circuit 459, and the scanner drive motor 465 according to an instruction from the printer control unit. The lamp control circuit 458 includes the scanner control circuit 4
In accordance with an instruction from 60, ON / OFF of the fluorescent lamp 3 and light amount control are performed. A rotary encoder 466 is connected to the drive shaft of the scanner drive motor 465, and the position sensor 462 detects the reference position of the sub-scanning drive mechanism. The analog image signal output from the CCD image sensor (the whole sensor composed of the CCD 8) 407 is subjected to processing such as A / D conversion by the processing circuit 451,
The data is sent to the writing unit via the interface 461.

The timing control circuit 459 outputs each signal according to the instruction from the scanner control circuit 460. That is, when reading is started, a transfer signal for transferring one line of data to the shift register and a shift clock pulse for outputting the shift register data one bit at a time are applied to the CCD image sensor 407. For the image reproduction system control unit, the pixel synchronization clock pulse CL
K, main scanning synchronization pulse LSYNC, and main scanning valid period signal
Output LGATE.

The pixel synchronization clock pulse CLK is CC
This signal is almost the same as the shift clock pulse given to the D image sensor 407. In addition, the main scanning synchronization pulse LSYN
C is substantially the same as the main scanning synchronization signal PMSYNC output from the beam sensor of the laser beam scanner (writing) unit, but the output is prohibited when no image is read. The main scanning valid period signal LGATE becomes high level H at the timing when the output data is regarded as valid data.

The scanner control circuit 460 is a main CPU.
When the reading start instruction is received from (b), the exposure lamp 3
Is turned on to start driving the scanner drive motor 465 to control the timing control circuit 459 to start reading the CCD image sensor 407. Further, the sub-scanning effective period signal FGATE is set to a high level H. When the sub-scanning valid period signal FGATE is set to the high level H, and after the time required to scan the maximum reading length (in this example, the size in the A-size longitudinal direction) in the sub-scanning direction elapses, the sub-scanning validity signal FGATE changes to the low level L. Become.

FIG. 6 shows an operation unit 30 provided in the copying machine main unit A.
0 shows a part of the appearance. Each key and display will be described. An input key 301 is a mode designation key for designating setting / cancellation of a black-and-white inversion mode for inverting black-and-white, a print start key 302 for inputting a copy start instruction, and 3
03 is a stop / clear key for inputting instructions for clearing the number of copy sets and interrupting copying, etc., 304 is a numeric keypad for inputting the number of copy sets, etc., 305 is a 7-segment display of the number of original sets, and 306 is the number of copies to be processed. Respectively are shown. Also, 31
1 is a gradation switch for specifying a gradation, 3
Reference numeral 12 denotes a gradation continuous shooting key for designating a continuous gradation for a plurality of copies.
7, 308, 309, and 310 are coordinate input keys used to designate an image area for performing gradation on a partial area. In addition, the operation unit 300 includes various keys and indicators such as a key for density adjustment, scaling, and a double-sided mode key, but these are omitted here.

The setting by key operation on the operation unit 300 is as follows.
The setting information is sent to the main CPU (a). The main CPU (a) sets operating conditions in the image processing unit based on the information. Further, the operating conditions of the machine are determined from the obtained information, and the information is transmitted to the sequence CPU (b) that performs sequence control at the time of starting copying.

FIG. 7 is a block diagram showing a schematic configuration of an image reading system (a part of the CCD image sensor 407 and the signal processing circuit 451). The reflected light from the original is photoelectrically converted into an analog electric signal by the CCD 8 driven by the CCD driver 102, and is amplified, converted into a voltage, and converted into an impedance by the analog circuit 103.
4 is converted into a digital image signal by the A / D converter 104. The density conversion unit 106 converts input image data according to the main scanning and sub-scanning addresses according to the settings of the CPU 107 (CPU for controlling the image reading system).

[0058] The timing controller 105, CCD
A timing signal required for driving, an A / D conversion clock, an image clock, and a main / sub-synchronization signal are generated from signals input from the timing control circuit 459 shown in FIG. 5 and supplied to each block.

FIG. 8 is a block diagram of the density converter 106 shown in FIG. The exclusive OR circuit 201 inverts and non-inverts the image according to an inversion control signal from the CPU 107.
Since the output of the CCD responds linearly to the amount of received light, if the quantization number for A / D conversion is 8 bits, 255 for white and 0 for black.
Normally, the inversion control signal is set to "H" to invert the image, and white is set to 0, black is set to 255, and the larger the value is, the higher the output density is set. When the monochrome mode is designated by pressing the monochrome inversion mode key 301 of the operation unit 300, the setting is reversed such that the inversion control signal is set to “L”, white is set to 255, and black is set to 0.

Reference numerals 206 and 207 denote RAMs for storing multipliers for the pixel data. This is a dual-port RAM, which has two input / output ports and has a built-in bus arbitration circuit that allows arbitrary addresses to be accessed asynchronously and independently from both ports. Before starting image reading from one port, C
PU107, in order from the address 0 of the multiplier for each image address in the sub-scanning direction in the RAM 206, stores the multiplier for each image address in the main scanning direction from address 0 in order to RAM 207. When reading an image, the address counters 204 and 2 are used.
05 gives an address corresponding to the progress of image reading to the other port of the RAMs 206 and 207, and the data read from the accessed RAM address is used as the multiplier 202, 207.
20 3, given as a multiplier.

[0061] The address counter 204, the signal shown in FIG. 11 supplied from the timing controller 105 is input. Line synchronization signal generated for each read line
No. The Hsyn c, by counting over the lifetime of the image one page, and outputs the 0 start count-up value as a sub-scanning address. The address painter 205 is supplied from the timing controller as shown in FIG.
A raw clock is input. The aforementioned line synchronization signal Hsync
Resets the address counter 205 and counts the pixel clocks in one read line, thereby outputting a 0-start up-count value as a main scanning address. The multiplier 202 converts the image density by multiplying the input pixel data individually by a multiplier read from the RAM 206 according to the sub-scanning address output from the address counter 204. The multiplier 203 includes an address counter 205
The image density is converted by multiplying pixel data input independently of sub-scanning by a multiplier read from the RAM 207 in accordance with the main scanning address.

FIG. 9 shows the RAMs 206 and 20 in FIG.
7 shows a memory map of FIG. RAM 206, 2
Reference numeral 07 denotes a dual port RAM from which CPU 107 writes D ₀ , D ₁ ,..., And Dn in order from address 0 before reading an image. In the case of gradation in the sub-scanning direction, for example, when the density is to be smoothly reduced within the range of 100% output at the leading edge of the image reading and 0% (image OFF) at the trailing edge, D ₀ to D
0 is stored from 1.00 toward n. If the number of images output lines to 4040 lines, from 4040/101 = 40, D ₀ to to D ₃₉ 1.00, 0.99 to D ₄₀ to D _79, · ·
, 0 is stored in D _{4000 to} D ₄₀₃₉ . At the time of actual image reading, as the reading line progresses, R
D _0, D ₁ from AM, · · ·, D ₄₀₃₉ is read as the multiplier, while the image head of the 40 line (pixel output value) ×
1.00, (pixel output value) x 0.99 during the next 40 lines
.. 40 lines at the rear end pole of the image are (pixel output value) × 0
(The multiplication value decreases by 0.01 every 40 pixels)
Is performed by the multiplier 202 shown in FIG.

In the case of gradation in the main scanning direction, when the output of one horizontal reading line is 20% at the beginning and 100% at the rear end, and the density is increased in 10 steps,
If the number of output pixels in one horizontal line is 4000 pixels, 40
00/10 The D ₀ to D ₀₉₉ from step = 400 0.20, D
₄₀₀ ~D in ₇₉₉ 0.28,..., And to D ₃₆₀₀ ~D ₃₉₉₉ 1.00
Will be stored. At the time of actual image reading, D ₀ , D ₁ ,
_.. , D ₃₉₉₉ is read out as a multiplier, and the first 400
(Sub-scan gradation output value) × 0.2 between pixels, (Sub-scan gradation output value) × for next 400 pixels
..., The last 400 pixels are calculated as (sub-scan gradation output value) × 1.00 (multiplication value is calculated every 400 pixels)
(Increment by 0.8) is performed by the multiplier 203 shown in FIG. 8, and the designated gradation is realized.

Next, continuous shooting of gradation will be described. In the present embodiment, in order to realize “gradation” over a plurality of copies for the same document, the following operation is performed in “gradation” with a plurality of copy instructions. When the gradation continuous shooting key 312 of the operation unit 300 is pressed, “gradation continuous shooting,
00% -0% ", the first sheet" 100% -76% "The second sheet" 75% -51% "The third sheet" 50% -26% "The fourth sheet" 25%- 0% ", so that all addresses are stored in the RAM 207 shown in FIG.
As described in the previous section, 1.00, 0.99,... 0.76 are stored in the RAM 206 by 4040 / (100-76 + 1) units from the first address of the first sheet 4040 from the first address of the second sheet. From the start address of the third sheet, 0.75, 0.74,..., 0.51 for each / (75-51 + 1), and 0.50, 0.49,..., 0.26 for the fourth sheet, each for 4040 / (50-26 + 1) Performs continuous copying by storing 0.25, 0.24,... 0.00 in 4040 / (25-0 + 1) units from the start address.

In the actual copying operation, Thus, the specified "gradation continuous shooting" can be realized. Next, processing near the boundary where the multiplier is switched will be described. As described above, D _{2000 to} D
By setting 0.50 to ₂₀₃₉ and 0.49 to D _{2040 to} D ₂₀₇₉ , even if density control is performed at 49% between 2000 and 2079 lines, density switching may be conspicuous near this boundary. . This is due to the problem of the tone reproducibility on the plotter side, and the tone information of the input pixels cannot be faithfully reproduced. The settings in the RAM at this time are shown by dotted lines in FIG. D (= 0.50) is set before the boundary, and D '(= 0.49) is set after the boundary is exceeded.

Therefore, in this embodiment, near the boundary,
By causing D and D 'to appear alternately, and by gradually changing the ratio of the appearance frequency, the switching of the density is made inconspicuous. This is shown by the solid line in FIG. Since a digital copying machine generally forms an image with about 16 scanning lines per 1 mm, when D is set as in this embodiment, switching of density does not appear on the output image.

Next, a partial gradation of the image area will be described. Now, the key 3 of the operation unit 300 shown in FIG.
The sub-scanning coordinates YL and YH as shown in FIG. 12 are designated by 07, 308, 309 and 310, and 100% to 0%.
%, And if the gradation SW 311 is pressed, the RAM 20
6 stores data as shown in FIG. 13, and the RAM 207 stores data of all 1.00 as shown in FIG. From DL to DH in FIG. 13 (DH-DL + 1)
1.00, 0.99,..., 0 are stored in order for each / 101.

Thereafter, when the copy start key 302 is depressed, an operation of (pixel output × 1.00 × 1.00) is performed on the sub-scanning coordinates Y0 to YL-1 and the area from YH + 1 to Ym. Therefore, the output is the original image. Y
For the area from L to YH (pixel output x D x 1.00)
Is calculated, 100
% -0% smooth gradation will be applied.

As shown in FIG. 16, coordinates (XL, YL)
100% to 0 for the area that can be expressed by (XH, YH)
Suppose that it is specified to perform smooth gradation of% and mask (erase) the image output outside the area,
Data is stored in the RAMs 206 and 207 in a configuration as shown in FIGS. 17 and 18, respectively. FIG.
7, 1.00, 0.99,..., 0 are stored for every (DH−DL + 1) / 101 from DL to DH.

[0070] region _{{(X 0, Y 0)} , (X L, Y L)}, a region _{{(X H, Y 0)} , (X n, Y L)}, a region {(X _0, Y _H) ,
(X _L , Y _m )} and the region {(X _H , Y _H ), (X _n , Y _m )} are subjected to an operation of (image output × 0 × 0), and the region {(X _L , Y ₀ ), (X _H , Y _L )} and the region {( _XL ,
(Y _H ), (X _H , Y _m )} (image output × 0 × 1.00)
Is performed, the region {(X ₀ , Y _L ), ( _XL , Y _H )}
And regions _{{(X H, Y L)} , (X n, Y H)} for performed the operations comprising (image output × 1.00 × 0), area {(X _L,
(Y _L ), (X _H , Y _H )} (image output × D × 1.00)
Is performed, and 100% -0% with respect to the designated area
, A smooth gradation is applied, and the area outside the area is masked by the image control circuit (c) to erase the image.

[0071]

As described above, according to the present invention, the concentration is
"Gradation" processing, which forms an image that gradually changes in density in the scanning direction or the main scanning direction, can be easily performed, so that it is difficult to prepare multiple copies with different gradations and cut and paste them as before. No extra work is required.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an outline of a mechanism section according to an embodiment of the present invention.

FIG. 2 is an enlarged plan view showing a writing unit of the copying machine main body A shown in FIG.

FIG. 3 is a block diagram showing a part of an electrical control unit of the copying machine shown in FIG.

FIG. 4 is a block diagram showing a part of an electrical control unit of the copying machine shown in FIG.

FIG. 5 is a block diagram of an image scanner unit centering on the scanner control circuit shown in FIG. 3;

FIG. 6 is a plan view showing a part of the appearance of an operation unit 300 provided in the copying machine main body A.

FIG. 7 is a block diagram showing a schematic configuration of an image reading system (part of the CCD image sensor 407 and a signal processing circuit 451 shown in FIG. 5).

FIG. 8 is a block diagram showing a configuration of a density conversion unit shown in FIG.

FIG. 9 shows a RAM 206 and a RAM 207 shown in FIG.
Is a memory map of FIG.

FIG. 10 is a timing chart showing a relationship between an Hsync signal and image output.

FIG. 11 is a timing chart showing a relationship between an Hsync signal and a vertical gate signal.

FIG. 12 is a plan view showing an image area.

FIG. 13 is a memory map of the RAM 206 at the time of gradation of a partial image area.

FIG. 14 is a memory map of a RAM 207 at the time of gradation of a partial image area.

FIG. 15 is a graph showing a data distribution near a boundary of a scanning line having different gradations.

FIG. 16 is a plan view showing an example of an image area according to designated coordinates.

FIG. 17 is a memory map of the RAM 206 in a case where a mask process is performed outside a region during gradation of a partial image region.

FIG. 18 is a memory map of a RAM 207 in a case where a mask process is performed on an area outside a partial image area during gradation.

[Explanation of symbols]

A: Copier body (image forming means) B: Automatic document feeder C: Sorter D: Double-sided reversing unit 8: CCD image sensor (a): Main CPU (b): Sequence CPU (c): Image control circuit 102: CCD driver 103: amplifier 104: A / D converter 105: timing controller 106: density conversion circuit 107: CPU ( multiplier setting means) 201: exclusive OR gate 202, 203: multiplier ( multiplication means) 204, 205: Address counters 206, 207: RAM 300: Operation board 301: White / black inversion mode key 302: Copy start key 307, 308, 309, 310: Image area designation key (image area designation means) 311: Gradation key ( Instruction means) 312: gradation continuous shooting key (instruction means)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-28170 (JP, A) JP-A-61-91661 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 1/387-1/409 G06T 5/00 100 G03F 1/00-1/16

Claims (6)

(57) [Claims] An original is scanned in a main scanning direction and a sub-scanning direction, and image data for each read pixel, a line synchronizing signal and
An image reading unit for outputting a pixel clock ; a first storage unit and a second storage unit ; a multiplier for each sub-scanning address is written in the first storage unit ;
A multiplier setting means for writing a multiplier for each main scanning address into a second storage unit; a line synchronization signal is counted and a sub-scanning address is first stored
Sub-scanning counter to be provided to the unit; counts the pixel clock and stores the main scanning address in the second memory
Main scanning counter to be given to the multiplier ; the multiplier output from the first storage unit and the output from the second storage unit
Multiplying means for multiplying the multiplier to the image data; and an instruction means for instructing the processing mode of the image data; equipped with, the multiplier setting unit, when there is a gradation indicated by the instruction means, the scanning line and for each at least one for each pixel
A multiplier for may sequentially varying the image density in the way the first and second
Write to storage; image reader. Wherein said multiplier setting unit, more graphene on the instruction means
If there is Deshon continuous instruction, reading the beginning of the multi-sheet
Of the original to be read from the beginning to the end in the sub-scanning direction
Writing multiplier for may sequentially <br/> varying concentrations for each scanning line in the first and second storage unit through to the tail of the scanning direction,
The image reading device according to claim 1. 3. The apparatus further comprises means for designating an image area.
Wherein the multiplier setting means is provided in the first and second storage units,
The address in the designated area includes each scan line and each pixel.
Multiplier for sequentially changing the image density at least on one side
To the address outside the specified area
The image reading device according to claim 1, wherein a multiplier is written. 4. An original is scanned in a main scanning direction and a sub-scanning direction, and image data for each read pixel, a line synchronizing signal and
An image reading unit for outputting a pixel clock ; a first storage unit and a second storage unit ; a multiplier for each sub-scanning address is written in the first storage unit ;
A multiplier setting means for writing a multiplier for each main scanning address into a second storage unit; a line synchronization signal is counted and a sub-scanning address is first stored
Sub-scanning counter to be provided to the unit; counts the pixel clock and stores the main scanning address in the second memory
Main scanning counter to be given to the multiplier ; the multiplier output from the first storage unit and the output from the second storage unit
Multiplying means for multiplying a multiplier to the image data; instruction means for instructing the processing mode of the image data; and an image forming means for forming an image represented by the product of the multiplier and the image data on a sheet; equipped with, the multiplier setting Means for receiving at least one gradation for each scanning line and each pixel when a gradation instruction is given by the instruction means.
A multiplier for may sequentially varying the image density in the way the first and second
Write to the storage unit; image forming apparatus. Wherein said multiplier setting unit, more graphene on the instruction means
If there is an instruction for continuous
Of the original to be read from the beginning to the end in the sub-scanning direction
Density sequentially for each scanning line through the end of the scanning direction
Writing a multiplier for changing to the first and second storage units;
The image forming apparatus according to claim 4 . And means for designating an image area.
The multiplier setting means stores the designated area in the first and second storage units.
Addresses within the area include a small number of scan lines and pixels.
At the same time, specify the multiplier for sequentially changing the image density
Write a multiplier for eliminating images at addresses outside the area.
The image forming apparatus according to claim 4, wherein the image forming apparatus is used.