JP2003251852A - Electrophotographic printer and image processing circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic printer which can carry out expanded/reduced printing beautifully. <P>SOLUTION: The electrophotographic printer 10 using a printing engine 12 of a pulse width modulation system is provided with an image data generating part 22 for generating image data expanded/reduced longitudinally, and a pulsation process part 21 for making the printing engine 12 form images expanded/reduced in a lateral direction from images expressed by image data on the basis of the image data generated by the image data generating part 22 by adjusting a shape of each pixel. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic printing apparatus having a print engine of a type in which drawing is performed by laser light, and an image processing circuit used to operate such a print engine. , Concerned.

[0002]

2. Description of the Related Art As is well known, some printers are capable of enlarging and reducing printing.

[0003]

The enlargement / reduction processing performed by an existing printer capable of performing enlargement / reduction printing is performed from an image composed of N × N pixels and from M × M pixels. Since a process for generating an image is performed, if a value that is not an integer value is specified as the scaling ratio (“1” is the same size) in the existing printer, as shown schematically in FIG. However, there is a problem that the print result that is not accurately scaled is discharged.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an electrophotographic printing apparatus which can perform enlargement / reduction printing more beautifully, and an image processing circuit which can realize an electrophotographic printing apparatus which can perform enlargement / reduction printing more beautifully. .

[0005]

In order to solve the above-mentioned problems, the electrophotographic printing apparatus according to the first aspect of the present invention responds to each pulse included in the supplied pulse signal according to the shape of the pulse. A print engine that forms on the paper pixels with different widths and positions in the laser scanning direction of the portion where the actual drawing is performed, content specification data that specifies the content of the printed material, and a printed material that should be generated from the content specified data. When the enlargement / reduction ratio designation data for specifying the enlargement / reduction ratio is given, only the number of pixels in the direction orthogonal to the laser scanning direction is determined according to the enlargement / reduction ratio specified in the enlargement / reduction ratio data based on the content regulation data. An image data generation unit that generates increased or decreased image data, and a pulse width that generates a pulse signal having a pulse shape corresponding to the supplied pixel data group and supplies the pulse signal to the print engine. Based on the adjustment section and the image data generated by the image data generation section, it performs processing to generate a pixel data group that can be supplied to the pulse width modulation section, and also specifies from the generated pixel data group with scaling ratio specification data. A process for generating a pixel data group in which an image obtained by scaling the image whose content definition data represents the content at a scaling ratio that will be formed on the paper by the print engine and supplying the pixel data group to the pulse width modulation unit is performed. Pixel data generation and supply unit,
Prepare

That is, in the electrophotographic printing apparatus according to the first aspect of the present invention, scaling is performed in pixel units in the direction perpendicular to the laser scanning direction, but in the laser scanning direction, scaling is not performed in pixel units. Instead, a configuration in which the scaling is performed by adjusting the shape of the pixel to be formed by the print engine,
Have. Therefore, this electrophotographic printing device functions as a device that can perform the scaling printing more beautifully than the conventional electrophotographic printing device because the scaling in the laser scanning direction is performed more accurately.

In realizing the electrophotographic printing apparatus according to the first aspect, as the pixel data generation / supply unit, the pixels that can be supplied to the pulse width modulation unit based on the image data generated by the image data generation unit. An original pixel data generation unit that generates a data group, and for each pixel data generated by the original pixel data generation unit, the pixel represented by the pixel data is expanded / reduced in the laser scanning direction at the expansion / contraction ratio specified by the expansion / contraction ratio specifying data. A virtual pixel data generation unit that generates virtual pixel data representing the pixel, and a pixel data group that can be supplied to the pulse width modulation unit from the virtual pixel data group generated by this virtual pixel data generation unit A device including a virtual image data conversion unit supplied to the width modulation unit can be used.

The electrophotographic printing apparatus according to the second aspect of the present invention is formed by a plurality of image forming units for forming toner images of different types on the photoconductor and a plurality of image forming units. A pulse signal supplied to each image forming unit in the print engine is provided with a print engine including a transfer unit that transfers a plurality of toner images onto a sheet in a superimposed manner, and a control unit that causes the print engine to perform printing. Is a unit for forming on the photoconductor a pixel in which the width and the position in the laser scanning direction of the portion to which toner is actually attached are changed for each pulse included in time series in accordance with the shape of the pulse. When the content specifying data that specifies the content of the printed matter and the scaling ratio designating data that specifies the scaling rate of the printed material to be generated from the content defining data are given as
Based on the content definition data, the image data in which only the number of pixels in the direction orthogonal to the laser scanning direction is increased or decreased according to the expansion / contraction ratio specified by the expansion / contraction ratio data is obtained for each of the plurality of image forming units. Generates a pulse signal having a shape corresponding to the supplied pixel data group, which is associated with different image forming units in the print engine and the image data generation unit to generate, and associates it with itself. A plurality of pulse width modulators that are supplied to the image forming unit and a pulse signal that is provided for each image forming unit in the print engine and that has a pulse shape corresponding to the supplied pixel data group. A plurality of pulse width modulators for supplying a specific image in the print engine and a pair of pulse width modulators respectively associated with different image forming units in the print engine. Based on the image data generated by the image data generation unit for the associated image forming unit, the pixel data group that can be supplied to the associated pulse width modulation unit is generated, and the generated pixel data group is generated. From the image data, the toner image obtained by expanding and contracting the image in which the content defining data represents the content at the expansion / contraction ratio specified by the expansion / contraction ratio specifying data is generated, and the pixel data group is generated. And a pixel data generation / supply unit that performs a process of supplying the pulse width modulation unit.

That is, the second electrophotographic printing apparatus of the present invention is an apparatus obtained by modifying the electrophotographic printing apparatus of the first aspect of the present invention into a so-called tandem type print engine. . Therefore, in this electrophotographic printing apparatus, the scaling in the laser scanning direction is performed more accurately,
It functions as a device that can perform enlargement / reduction printing more beautifully than the conventional electrophotographic printing device.

Further, in the electrophotographic printing apparatus according to the third aspect of the present invention, for each pulse included in the supplied pulse signal, the laser scanning direction of a portion in which drawing is actually performed according to the shape of the pulse. A print engine that forms pixels with different widths and positions on the paper, content specification data that specifies the content of the printed matter, and enlargement / reduction ratio specification data that specifies the enlargement / reduction rate of the printed material to be generated from the content specification data are given. Image data generation unit that generates unscaled image data based on the content regulation data, and a pulse signal having a pulse having a shape corresponding to the supplied pixel data group to generate a print engine. A pulse width modulation unit to be supplied to the pulse width modulation unit and a process of generating a pixel data group that can be supplied to the pulse width modulation unit based on the image data generated by the image data generation unit. At the same time, from the generated pixel data group, the print engine forms an image on paper by scaling the image in which the content defining data represents the content at the scaling rate specified by the scaling rate specifying data. And a pixel data generation / supply unit that performs a process of generating a pixel data group and supplying the pixel data group to the pulse width modulation unit.

That is, in the electrophotographic printing apparatus according to the third aspect of the present invention, the shape of the pixel to be formed by the print engine is not scaled in pixel units in both the laser scanning direction and the direction perpendicular to the laser scanning direction. The configuration is such that the expansion / contraction is performed by the adjustment. Therefore, this electrophotographic printing device is a device that can perform expansion / reduction printing more neatly than the conventional electrophotographic printing device because both the laser scanning direction and the expansion / contraction in the direction perpendicular to the laser scanning direction are performed more accurately. Will function as.

The electrophotographic printing apparatus according to the fourth aspect of the present invention (the electrophotographic printing apparatus according to claim 5) is the electrophotographic printing apparatus according to the third aspect of the present invention in a so-called tandem type. Since it is a device modified to have a print engine, this electrophotographic printing device is also more accurate in both the laser scanning direction and the scaling in the direction perpendicular to the laser scanning direction. It functions as a device that can perform enlarged / reduced printing more beautifully than a photographic printing device.

In implementing the electrophotographic printing apparatus according to each aspect of the present invention, a data receiving unit that receives data representing a printed matter to be generated from an external device and supplies the data to the image data generating / supplying unit is provided. , May be added, and such a data receiving unit may not be added. In other words, the electrophotographic printing apparatus according to each aspect of the present invention may be realized as a printer or a multifunction machine, or as a copy.

Since the image processing circuit of the present invention is a circuit used in the electrophotographic printing apparatus of the present invention, the use of the image processing circuit of the present invention makes it possible to use the image processing circuit of the present invention more than the conventional electrophotographic printing apparatus. Therefore, it is possible to easily manufacture the electrophotographic printing device that can perform the expansion / contraction printing neatly.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment> FIG. 1 shows the arrangement of an electrophotographic printing apparatus according to the first embodiment of the present invention.

Electrophotographic printing apparatus 1 according to the first embodiment
Reference numeral 0 denotes a so-called color laser printer, which includes a control unit 11 and a print engine 12 as main components as illustrated. Although not shown, the electrophotographic printer 10 is also provided with an operation panel including a small-sized liquid crystal display and a plurality of push button switches.

The print engine 12 used in the electrophotographic printing apparatus 10 is a tandem type print engine having four image forming units (a unit including a laser scanning system, a photoconductor, a developing device, etc.). . This print engine 1
2 is drawing (exposure) in each pixel by adjusting the shape (width and position) of each pulse in the pulse signal supplied to each image forming unit (laser scanning system in the image forming unit)
The width and position in the laser scanning direction of the portion (hereinafter, referred to as a drawing portion) where
It can be controlled in units.

The control unit 11 is a unit for utilizing the print engine 12 (making the print engine 12 perform printing). The control unit 11 includes an image data generation unit 22.
A clock generator 23 and four pulse processing units 21 each connected to a specific image forming unit in the print engine 12.

The clock generating section 23 is a circuit for generating a video clock (CLK in the figure) of a predetermined frequency, and the video clock generated by the clock generating section 23 is supplied to each section in the control section 11. . Although not shown, a horizontal synchronization signal indicating one laser scanning period in each image forming unit is also supplied to each unit in the control unit 11.

The image data generator 22 generates image data (pixel data group) having contents corresponding to print data transmitted from a host device (not shown) for each image forming unit (for each toner).
Image data generated for each image forming unit,
It is a unit composed of a CPU, a communication I / F circuit, a ROM, a RAM, and the like, which performs a process of supplying to the pulse processing unit 21 connected to the image forming unit in units of pixel data.

When the image data generator 22 receives print data instructing enlargement / reduction, the image data generator 22 generates four types of image data which are not enlarged / reduced for the first page, and is instructed in the print data. After setting the enlargement / reduction ratio that has been set in each pulse conversion processing unit 21, the corresponding pulse conversion processing unit 21 is caused to perform each of the generated image data, and no expansion / reduction is performed for each of the second and subsequent pages. It is configured to generate seed image data and cause the corresponding pulse processing unit 21 to process each generated image data.

Each of the four pulse processing units 21 included in the control unit 11 is connected to itself with a pulse group (pulse signal) having contents corresponding to the supplied image data (pixel data group). It is a unit that supplies the image forming unit (hereinafter also referred to as a corresponding image forming unit). The electrophotographic printing apparatus 10 includes one image processing circuit (ASIC) that functions as the four pulse processing units 21.
It is a device equipped with.

As shown in the drawing, each pulsing processing section 21 is composed of an image data correction section 32 (corresponding to a pixel data generation / supply section) and a pulse width modulation section 33.

The pulse width modulator 33 uses a video clock from the clock generator 23 to perform a process of generating a pulse having a shape corresponding to the pixel data supplied from the image data corrector 32 and supplying it to the corresponding image forming unit. It is a circuit that executes (repeats) in a synchronized manner. The pulse width modulator 33 is supplied with pixel data representing a pixel having a width of "100" and generates a pulse corresponding to the pixel data, for example, a pulse having a shape as shown in FIG. Has become.

The image data correction unit 32 is a circuit having a structure in which a virtual pixel data generation module and a virtual pixel data conversion module are connected via a buffer (not shown).

The virtual pixel data generation module (corresponding to the virtual pixel data generation unit) has a scaling ratio register for storing the scaling ratio set by the image data generation unit 22. Every time the pixel data is supplied, the pixel having the width “100” represented by the pixel data is expanded / reduced in the width direction (laser scanning direction) at the expansion / contraction ratio stored in the expansion / contraction ratio register. This is a module that performs processing of generating virtual pixel data that represents the ratio of the non-drawing portion and the positional relationship with the original pixel and that has the width of each portion enlarged / reduced, and stores the virtual pixel data in the buffer.

The virtual pixel data conversion module (corresponding to a virtual pixel data conversion unit) starts from a pixel of width "100" having the same content as the pixel row represented by the virtual pixel data group generated by the virtual pixel data generation module. Is a module that performs a process of generating a pixel data group that represents the pixel array and supplying the generated pixel data to the pulse width modulation unit 33. This corrected image data generation module is a module that starts reading virtual pixel data from the buffer after the virtual pixel data generation module has generated virtual pixel data for a predetermined number of pixels at the beginning of the line. .

The operation contents of the virtual pixel data generation module and the virtual pixel data conversion module will be further described below with reference to FIG. 3 by taking the case where the scaling ratio set by the image data generation unit 22 is 1.25 as an example. This will be specifically described.

In the state where the enlargement / reduction ratio set by the image data generator 22 is 1.25, as the pixel data (original pixel data in the figure) for the first pixel (the pixel at the beginning of the line), the width " When a pixel representing a pixel having a drawing portion of 40 "and a non-drawing portion having a width of" 60 "on the end side (pixel having a width of" 100 ") is supplied, the virtual pixel data generation module sets Width “50” (= INT (40 ×
1.25)) has a drawing part and the width is "75" at the end.
(= INT (100 × 1.25) −INT (40 × 1.25)) virtual pixel data (hereinafter, referred to as first virtual image data) representing a pixel (pixel of width “125”) having a non-drawing portion Is generated and output (stored in the buffer).

Pixel data relating to the second pixel supplied thereafter represents a pixel having a drawing portion having a width of "50" on the head side and a non-drawing portion having a width of "50" on the tail side. If there is, the virtual pixel data generation module has a non-drawing portion of width “62” (= INT (50 × 1.25)) on the head side and a width “63” (= INT (100
X1.25) -INT (50 x 1.25)) is generated, and virtual pixel data (hereinafter, referred to as second virtual image data) representing a pixel (pixel having a width of "125") is generated. Output. Further, if the image data of the third pixel supplied thereafter represents a pixel having a drawing portion with a width of “70” on the head side and a non-drawing portion with a width of 27 on the tail side, The pixel data generation module has a drawing portion having a width “88” (= INT (70 × 1.25)) on the head side and a width “37” (= INT (100 × 1.25) −I) on the tail side.
Virtual pixel data (hereinafter referred to as the third pixel) representing a pixel (pixel of width “125”) having a non-drawing part of NT (70 × 1.25)
Virtual image data) is generated and output.

The image data (pixel data group) supplied to the virtual pixel data generation module is image data that has already been expanded or reduced in the vertical direction, and therefore, it corresponds to each virtual pixel data thus generated. If the laser drawing system in the corresponding image forming unit can execute the contents operation,
The corresponding image forming unit can form a toner image that has been enlarged or reduced at the enlargement or reduction ratio designated in the print data.

However, the pulse width modulator 33 has a width of "1".
Since it is only possible to process the pixel data representing the 00 ″ pixel, each virtual pixel data cannot be directly supplied to the pulse width modulation unit 33.

Therefore, in the image data correction section 32, the virtual pixel data group generated by the virtual pixel data generation module by the virtual pixel data conversion module is
The width is "100", which is the same as the pixel row they represent.
The pixel data is converted into a pixel data group representing a pixel array of pixels and is supplied to the pulse width modulation unit 33.

That is, the above-mentioned first to third virtual pixel data (to be precise, the first virtual image data, the second virtual pixel data and a part of the third virtual image data) are as shown in FIG. Has pixel data representing a pixel having a width "50" on the leading side and a non-drawing portion having a width "50" on the trailing side, and a non-drawing portion having a width "87" on the leading side. , Is converted into image data representing a pixel having a drawing portion having a width of 13 on the tail side and image data representing a pixel which is a drawing portion in all parts, and is supplied to the pulse width modulator 33.

During the processing by the virtual pixel data conversion module, the image data to be supplied to the pulse width modulator 33 has a pixel whose central portion is a non-drawing portion (the drawing portion is divided into the leading end side and the trailing end side). Pixel data representing existing pixels). Since the pulse width modulation unit 33 used in the electrophotographic printing apparatus 10 cannot process such pixel data, the virtual pixel data conversion module is originally supplied to the pulse width modulation unit 33. If the image data to be represented is a pixel in which the central portion is the non-drawing portion, the pixel in which the drawing portion with the smaller width is the non-drawing portion is used instead of the pixel data. It is configured to provide pixel data representing.

As described above, in the electrophotographic printing apparatus 10, the enlargement / reduction of the vertical direction (direction perpendicular to the laser scanning direction) is performed by the same procedure as the conventional procedure, but the horizontal direction (laser scanning direction). The enlargement / reduction of () is performed by adjusting the shape of the pixel formed by the print engine 12. Therefore, by using this electrophotographic printer 10,
In the enlargement / reduction printing, a finer printing result can be obtained than in the conventional electrophotographic printing apparatus in which the enlargement / reduction in the vertical direction and the enlargement / reduction in the horizontal direction are performed in pixel units.

<Second Embodiment> An electrophotographic printing apparatus according to a second embodiment of the present invention is a color laser printer capable of enlarging printing.

As shown in FIG. 4, the electrophotographic printing apparatus 50 according to the second embodiment includes a control unit 51 and a print engine 52 as main constituent elements.

The print engine 52 used in the electrophotographic printing apparatus 50 is the same as the print engine 12 used in the electrophotographic printing apparatus 10.

The control unit 51 is a unit for utilizing the print engine 52 (making the print engine 52 perform printing), and includes an image data generating unit 62 and a clock generating unit 6.
3 and four pulse processing units 61 respectively connected to specific image forming units in the print engine 52.

The clock generating section 54 constituting the control section 51 is the same circuit as the clock generating section 14.

Further, the image data generation unit 62 generates image data (pixel data group) having contents corresponding to print data transmitted from a host device (not shown) for each image forming unit (for each toner), and each image data is generated. This is a unit that supplies the image data generated for the image forming unit, in pixel data units, to the pulse processing unit 61 connected to the image forming unit.

The image data generating section 62 is a unit having the same hardware configuration as the image data generating section 22. Then, like the image data generation unit 22, when the image data generation unit 22 receives the print data instructing the enlargement, the image data generation unit 62 generates four types of image data that are not enlarged for the first page. After setting the enlargement ratio instructed in the print data in each pulse conversion processing unit 61, the generated pulse image processing unit 61 is caused to perform each generated image data, and for each page after the second page, The four types of image data that have not been enlarged are generated, and the generated pulse image processing units 61 are caused to perform the generated image data.
It is configured.

Each of the four pulse processing units 61 included in the control unit 51 is connected to a pulse group (pulse signal) having a content corresponding to the supplied image data (pixel data group). It is a unit that supplies the image forming unit (hereinafter also referred to as a corresponding image forming unit). The electrophotographic printing device 50 also includes these four pulse processing units 61.
It is a device in which one image processing circuit (ASIC) that functions as is mounted.

The pulse width modulation section 73 included in each pulse conversion processing section 61 has the same circuit as the pulse width modulation section 33.

The image data correction unit 72 included in each pulse processing unit 61 is a circuit in which a vertical expansion module is added to the image data correction unit 32. However, the virtual pixel data generation module provided in the image data correction unit 72 does not have a scaling ratio register dedicated to its own module, and the virtual pixel data generation module provided in the image data correction unit 72 may also use the vertical enlargement module. It operates by referring to the referred scaling factor register. In addition, the virtual pixel data conversion module provided in the image data correction unit 72 is a circuit that operates in synchronization with the vertical enlargement module (instead of outputting a pixel data group for one line at a fixed cycle, The expansion module outputs a pixel data group when the pixel data group can be accepted).

The function of the vertical enlargement module included in the image data correction unit 72 will be described below with reference to FIGS. 5 and 6.

As shown in FIG. 5, the vertical expansion module is a module whose main constituent elements are a residual raster buffer and an arithmetic unit.

The residual raster buffer stores one line of pixel data and height information H (numerical value information; details will be described later).
It is a buffer that can store one line.

The calculation unit is a calculation module that periodically performs the following processing.

When the height information is not stored in the residual raster buffer, the arithmetic unit receives the pixel data group for one line from the virtual pixel data conversion module, and the pixel data group is processed by the pulse width modulation unit 73. And the height information H (= R-1) corresponding to the value obtained by subtracting "1" from the scaling rate R stored in the scaling rate register and the remaining raster buffer. Remember.

In the residual raster buffer, one
When the height information H less than “1” is stored, the calculation unit receives the pixel data group for one line from the virtual pixel data conversion module and also extracts the pixel data group for one line from the residual raster buffer. (The remaining raster buffer is in a state where no data is stored). Then, the pixel data group for one line extracted from the residual raster buffer and the pixel data group for one line received from the virtual pixel data conversion module are combined at a ratio of H: 1−H to obtain one line. A pixel data group for a minute is generated and supplied to the pulse width modulator 73. here,
“Composite at a ratio of H: 1−H” means that 1 is calculated from the corresponding two pixel data in a procedure as schematically shown in FIG.
A process of generating one pixel data, that is, a pulse (a pulse having a shape that cannot be generated by the pulse width modulation unit 73) obtained by weighting and adding the pulses represented by each pixel data in the height direction, This is a process of generating pixel data representing a pulse having a shape that can be generated by the pulse width modulation unit 73 having the same area and having the same center of gravity position for each pixel data of one line.

Then, in the residual raster buffer, one
When the height information H less than “1” is stored, the calculation unit determines that the pixel data group for one line received from the virtual pixel data conversion module and the height that matches “R− (1-H)”. Processing for storing the information H on the residual raster buffer is also performed.

Further, the arithmetic unit stores in the residual raster buffer,
When one piece of height information H of “1” or more is stored, the pixel data group for one line is received from the residual raster buffer without receiving the pixel data group for one line from the virtual pixel data conversion module. Is read (the image data group is left in the residual raster buffer). Then, the pixel data group for one line read from the residual raster buffer is supplied to the pulse width modulation unit 73, and the value of the height information H in the residual raster buffer is decreased by "1".

Further, the arithmetic unit stores in the residual raster buffer,
If two pieces of height information H are stored (in this case, 2
If the sum of the two height information exceeds "1"), the pixel data group for one line from the residual raster buffer is received from the residual raster buffer without receiving the pixel data group for one line from the virtual pixel data conversion module. And the pixel data group for one line on the tail side is read (1 on the head side)
The pixel data group for the line is erased from the residual raster buffer, and the image data group on the tail side is left in the residual raster buffer). Then, the pixel data group for one line on the leading side and the pixel data group for the trailing side are combined at a ratio of H: 1-H (H is height information regarding the leading side line), and The pixel data group of is generated and supplied to the pulse width modulation unit 73. In addition, the calculation unit also performs a process of reducing the value of the height information H regarding the pixel data group remaining in the residual raster buffer by “1”.

That is, the image data correction unit 72 provided in the electrophotographic printing apparatus 50 according to this embodiment is
When the scaling ratio is 1.25, the image data having the content shown in FIG. 7B is generated from the image data having the content shown in FIG. Then, in the electrophotographic process, the isolated toner approaches other toners, so that in the electrophotographic printing apparatus 50, as shown in FIG.
The printing result as shown in (C) is obtained.

As described above, in the electrophotographic printing apparatus 50 according to the second embodiment, both the vertical direction (direction perpendicular to the laser scanning direction) and the horizontal direction (laser scanning direction) expansion / reduction are performed. This is an apparatus that is performed by adjusting the shapes of the pixels formed in the print engine 12. Therefore, by using this electrophotographic printing apparatus 50, a print result which is cleaner than that of the conventional electrophotographic printing apparatus in which both vertical and horizontal scaling is performed in pixel units at the time of scaling printing can be obtained. . In addition, it is possible to obtain a print result that is cleaner than that of the electrophotographic printing apparatus 10 according to the first exemplary embodiment in which vertical scaling is performed in pixel units.

<Modification> The electrophotographic printers 10 and 50 described above perform a process of generating virtual pixel data and a process of generating pixel data that can be supplied to the pulse width modulator 33 from the generated virtual pixel data. Image processing circuit (ASI
Although it is the device performed in C), the electrophotographic printing devices 10 and 50 may be modified so that these processes are performed by the image data generation unit 22 (by the CPU). Further, the electrophotographic printing apparatuses 10 and 50 are apparatuses using the image processing circuits functioning as the four pulse processing units 21 and 61, but the image processing circuits are used as the pulse width modulation units 33 and 73. It may be assumed that it does not have the function of.

Further, the image data correction unit 32 may be configured to perform the scaling in the vertical direction and then the scaling in the horizontal direction, and the scaling in the horizontal direction and the scaling in the vertical direction are performed in parallel. It may be done in advance.

The electrophotographic printers 10 and 50 are
Although the laser beam printer uses the tandem type print engines 12 and 52, the electrophotographic printer 1
The technology used in 0 and 50 may be applied to a laser beam printer using a print engine having only one image forming unit, and an electrophotographic printing apparatus (not a laser beam printer) ( Needless to say, it may be applied to a fax machine, a copying machine, a multifunction machine).

[0062]

According to the present invention, it is possible to obtain an image processing circuit capable of realizing an electrophotographic printing apparatus capable of performing fine expansion / reduction printing and an electrophotographic printing apparatus capable of performing fine expansion / reduction printing more beautifully.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an electrophotographic printing apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of pulses output by a pulse width modulation unit used in the electrophotographic printing apparatus according to the first embodiment.

FIG. 3 is a diagram for explaining an operation of a pulse processing unit used in the electrophotographic printing apparatus according to the first embodiment.

FIG. 4 is a configuration diagram of an electrophotographic printing apparatus according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram of a vertical enlargement module used in the electrophotographic printing apparatus according to the second embodiment.

FIG. 6 is a diagram for explaining the operation of the vertical enlargement module.

FIG. 7 is a diagram for explaining the operation content during enlarged printing of the electrophotographic printing apparatus according to the second embodiment.

FIG. 8 is a diagram for explaining a problem in a conventional printer.

[Explanation of symbols]

10, 50 Electrophotographic printing device 11, 51 Control unit 12,52 print engine 21, 62 Pulse processing unit 22, 62 Image data generator 23, 63 Clock generator 32, 72 Image data correction unit 33, 73 Pulse width modulator

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 1/29 H04N 1/393 5C074 1/393 B41J 3/00 M 5C076 F term (reference) 2C362 CB34 CB35 2H027 EA18 EB04 FA06 FD08 ZA07 2H030 AD06 AD13 BB02 2H076 AB05 AB12 AB72 DA19 EA01 5C062 AA05 AB08 AB41 AB47 AC04 AC31 AF11 5C074 AA02 BB02 BB17 DD05 DD07 DD15 EE02 5C076 AA21 AA22 BA01 BB22CB01

Claims (9)

[Claims] 1. A printing method, in which, for each pulse included in a supplied pulse signal, pixels are formed on a paper by changing a width and a position in a laser scanning direction of a portion in which actual drawing is performed according to the shape of the pulse. When the engine, the content regulation data that regulates the content of the printed matter, and the enlargement / reduction rate designation data that specifies the enlargement / reduction rate of the printed matter to be generated from the content regulation data are given, the laser scanning direction is based on the content regulation data. An image data generation unit that generates image data in which only the number of pixels in the direction orthogonal to is increased or decreased according to the scaling rate specified by the scaling rate data, and a shape corresponding to the supplied pixel data group A pulse width modulation unit that generates a pulse signal composed of pulses and supplies the pulse signal to the print engine, and the pulse based on the image data generated by the image data generation unit. An image in which the processing for generating a pixel data group that can be supplied to the width modulation unit is performed, and the content definition data represents the content of the generated pixel data group at a scaling rate specified by the scaling rate designating data. And a pixel data generation / supply unit that performs a process of generating a pixel data group in which an image that has been enlarged or reduced is formed on the paper by the print engine and supplying the pixel data group to the pulse width modulation unit. Electrophotographic printing device. 2. The original pixel data generation unit, which generates a pixel data group that can be supplied to the pulse width modulation unit based on the image data generated by the image data generation unit, For each pixel data generated by the original pixel data generation unit, virtual pixel data representing a pixel obtained by expanding or contracting the pixel represented by the pixel data in the laser scanning direction at a scaling rate specified by the scaling rate designating data is generated. A virtual pixel data generation unit, and a virtual image that is supplied to the pulse width modulation unit by generating a pixel data group that can be supplied to the pulse width modulation unit from the virtual pixel data group generated by this virtual pixel data generation unit. The electrophotographic printing apparatus according to claim 1, further comprising a data conversion unit. 3. A plurality of image forming units for forming different kinds of toner images on a photoconductor, and a transfer unit for transferring a plurality of toner images formed by the plurality of image forming units onto a sheet in an overlapping manner. A print engine including a print engine and a control unit that causes the print engine to perform printing, and each image forming unit in the print engine includes a pulse signal for each pulse included in the supplied pulse signal in time series. Is a unit for forming a pixel on the photoconductor in which the width and position of the portion to which the toner is actually attached in the laser scanning direction is changed according to the shape of, and the control unit is provided with content defining data that defines the content of the printed matter. When the scaling ratio designating data designating the scaling ratio of the printed matter to be generated from the content defining data is given, the direction orthogonal to the laser scanning direction based on the content defining data. An image data generation unit that generates image data for each of the plurality of image forming units, the image data having increased or decreased only the number of pixels in accordance with the scaling ratio specified by the scaling ratio data; A plurality of pulses generated by generating pulse signals each having a shape corresponding to the supplied pixel data group, which are associated with different image forming units, and are supplied to the image forming unit associated with itself. A width modulation section and a pulse signal, which is provided for each image forming unit in the print engine and has a shape according to the supplied pixel data group, is generated and supplied to a specific image forming in the print engine. A plurality of pulse width modulators, which are associated with different image forming units in the print engine, respectively. Based on the image data generated by the image data generation unit, a process of generating a pixel data group that can be supplied to the associated pulse width modulation unit is performed, and the scaling ratio designation data is generated from the generated pixel data group. A pixel data group in which a toner image obtained by expanding or contracting an image in which the content definition data represents the content at a specified expansion / contraction ratio is formed by the image forming unit is generated and supplied to the pulse width modulation unit. An electrophotographic printing apparatus comprising: a pixel data generation / supply unit that performs processing. 4. A printing method in which, for each pulse included in a supplied pulse signal, pixels are formed on a paper by changing the width and position in the laser scanning direction of a portion in which actual drawing is performed according to the shape of the pulse. When the engine, the content specification data that specifies the content of the printed matter, and the enlargement / reduction rate specification data that specifies the enlargement / reduction rate of the printed material to be generated from the content specification data, are enlarged / reduced based on the content regulation data. Image data generation unit that generates image data that does not exist, a pulse width modulation unit that generates a pulse signal having a pulse having a shape corresponding to the supplied pixel data group, and supplies the pulse signal to the print engine, and the image data generation unit Based on the image data generated by, performs a process of generating a pixel data group that can be supplied to the pulse width modulation unit, and from the generated pixel data group, And generating a pixel data group in which an image obtained by scaling the image in which the content defining data represents the content at the scaling rate designated by the scaling rate designating data is formed on the paper by the print engine. An electrophotographic printing apparatus, comprising: a pixel data generation / supply unit that performs a process of supplying the pulse width modulation unit. 5. A plurality of image forming units for forming different kinds of toner images on a photoconductor, and a transfer unit for superposing and transferring a plurality of toner images formed by the plurality of image forming units on a sheet. A print engine including a print engine and a control unit that causes the print engine to perform printing, and each image forming unit in the print engine includes a pulse signal for each pulse included in the supplied pulse signal in time series. Is a unit for forming a pixel on the photoconductor in which the width and position of the portion to which the toner is actually attached in the laser scanning direction is changed according to the shape of, and the control unit is provided with content defining data that defines the content of the printed matter. Image data that has not been subjected to scaling based on the content-defining data when given the scaling-rate designating data that specifies the scaling rate of the printed matter to be generated from the content-defining data. A pulse signal having a pulse shape having a shape corresponding to the supplied pixel data group, which is associated with the image forming unit in the print engine and different from each other in the print engine, is generated and associated with itself. A plurality of pulse width modulators to be supplied to the image forming unit; and a pulse signal, which is provided for each image forming unit in the print engine and has a shape according to the supplied pixel data group, to generate the pulse signal. A plurality of pulse width modulators for supplying specific image formation in the engine, and image data generation for the corresponding image formation units respectively associated with different image formation units in the print engine. Based on the image data generated by each unit, the pixel data group that can be supplied to the associated pulse width modulation unit is generated, and the generated pixel data is generated. From the group, a pixel data group in which a toner image in which the image in which the content defining data represents the content is scaled at the scaling rate designated by the scaling rate designation data is formed by the image forming unit is generated. And a pixel data generation / supply unit that performs a process of supplying the pulse width modulation unit to the pulse width modulation unit. 6. The data receiving unit according to claim 1, further comprising a data receiving unit that receives data representing a printed matter to be generated from an external device and supplies the data to the image data generating / supplying unit. The electrophotographic printing apparatus according to any one of claims. 7. A printing method for forming a pixel on a paper, for each pulse included in a supplied pulse signal, in which a width and a position in a laser scanning direction of a portion to be actually drawn is changed according to a shape of the pulse. An image processing circuit used to operate the engine, and a scaling ratio designation data storage unit in which scaling ratio designation data that specifies the scaling factor of the printed matter to be generated is set, and the pixels supplied based on the image data. A process of generating a pulse signal having a pulse shape corresponding to the data group to generate a pixel data group that can be supplied to the pulse width modulation unit that is supplied to the print engine is performed, and the printing is performed from the generated pixel data group. In a form in which the image of the image represented by the image data is scaled by the engine at the scaling rate indicated by the scaling rate designation data stored in the scaling rate designation data storage unit. The image processing circuit characterized by dividing it into formed by generating the pixel data group comprises a pixel data generation and supply unit for performing the processing to be supplied to the pulse width modulation unit. 8. The image processing according to claim 7, further comprising a pulse width modulator that generates a pulse signal having a shape corresponding to the supplied pixel data group and supplies the pulse signal to the print engine. circuit. 9. The image data is image data that has been enlarged or reduced in a direction orthogonal to a laser scanning direction, and the pixel data generation / supply unit uses the generated pixel data group to generate the pixel data by the print engine. An image represented by the image data is printed to generate a pixel data group which is to be expanded and reduced in the laser scanning direction at the expansion / contraction ratio indicated by the expansion / contraction ratio specifying data stored in the expansion / contraction ratio specifying data storage unit. 9. The image processing circuit according to claim 7, wherein the image processing circuit supplies the pulse width modulation unit to the pulse width modulation unit.