JPH11129534A - Image recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the cost reduction by a method wherein image data is read from a memory means for storing at least a part of image data by an order corresponding to a driving order of each solid recording element at a different timing with respect to each solid recording element array head. SOLUTION: Image data of each of colors Y, M, C, K inputted from a scanner section is inputted to a binarizing processing section 301 and the binarizing processing section 301 coverts the image data of which each pixel is represented by 256 gradations in 8 bits to image data in a pseudo intermediate tone in one bit. The image data of each of colors Y, M, C, K is inputted to a memory 310 through respective memory control sections 306-309 in a predetermined order such that one line of the image data is serially written thereinto in a raster-like manner. The image data of each of colors Y, M, C, K written into the memory 310 is read through the memory control sections 306-309 by being controlled to be read at a timing corresponding to each of the colors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus, such as a copying machine or a printer, for recording an image using a solid-state recording element array.

[0002]

2. Description of the Related Art In recent years, a function of scanning a solid-state recording element has been provided.
A self-scanning type recording chip provided inside the recording chip has been proposed. According to this, within each recording chip, N
For example, 128 solid-state recording elements are, for example, 600 dpi.
By arranging the image data corresponding to each of these solid-state recording elements serially into a driver, the recording elements can be driven one by one in a time-division manner. These are disclosed in JP-A-1-238962.
JP-A-2-208067, JP-A-2-21217
0, JP-A-3-20457, JP-A-3-19497
8, JP-A-4-296579, JP-A-4-5872
JP-A-4-23367, JP-A-4-296579
And Japanese Patent Application Laid-Open No. Hei 5-48971.

By arranging M solid-state recording element array chips (hereinafter referred to as recording chips) each having the 128 solid-state recording elements arranged thereon into M, for example, 56 solid-state recording element array heads (hereinafter referred to as recording heads). , The short side of the A3 sheet can be covered, and a desired image can be recorded on the A3 sheet.

FIG. 8 shows a driving order of each solid-state recording element in a recording head in which 56 recording chips in which 128 solid-state recording elements are arranged are further arranged.
The numbers indicated by the marks indicate the order of driving, and the solid-state recording elements indicated by the same numbers are driven at the same time.

[0005]

However, since the image data input to the recording head is generally in the form of a raster, the image data input in a raster form is driven by the driving of the recording head. It is necessary to convert the order according to the order. FIG. 8 shows a conventional example.

In FIG. 9, reference numerals 80-1 to 80-56 denote the recording chips described above, and reference numerals 92-1 to 92-56 denote one.
The 28-bit shift register 91-1 to 91-56 is a latch circuit for latching image data of 128 pixels corresponding to the self-scanning recording chips 80-1 to 80-56, respectively. I do.

First, image data of 128 × 56 pixels on the first line is input from a signal line 93 having a width of 1 bit.
These image data are stored in shift registers 92-1 to 92-
56 are sequentially input. When all of the 128 × 56 image data have been input to the shift registers 92-1 to 92-56, the latch 91 corresponding to each shift register
-1 to 91-56 each convert the image data into 128 bi
latches for each t, and subsequently shift registers 92-1 to 92-1
The pixel data of the second line is input to −56.
On the other hand, the latch circuits 91-1 to 91-56 serially input the held 128-bit image data to the corresponding recording chips 80-1 to 80-56 one bit at a time.

As described above, each recording chip 8
In 0-1 to 80-56, the printing elements are sequentially scanned, and are selectively driven in accordance with serially input pixel data.

As described above, in order to convert one line of image data serially input in a raster form into an order suitable for the order of driving by the recording head as described above, the latches 91-1 to 91-56 are used. And shift registers 92-1 to 92
It was necessary to provide -56 or the like.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and provides an image recording apparatus having a plurality of solid-state recording element array heads for driving a solid-state recording element in each solid-state recording element array chip in a time-division manner at low cost. The purpose is to:

[0011]

According to the present invention, there is provided an image recording apparatus comprising: a plurality of solid recording element array heads each comprising a plurality of solid recording element arrays in which a plurality of solid recording elements are arranged; Input means for inputting image data corresponding to each of the array heads in a raster form, storage means for storing at least a part of each of the image data input by the input means, and storage means for storing in the storage means Reading means for reading out the read image data from each of the solid-state recording element array heads, and the solid-state recording element array of each of the solid-state recording element array heads according to the image data read by the reading means. An image recording apparatus having a plurality of driving means for driving each of the solid-state recording elements arranged in a time-division manner in a time-division manner. The order is different from the order in which the storage means is input in the form of a raster, and the order according to the order in which the plurality of driving means of each solid-state recording element array head drives the solid-state recording elements. Order control means for causing the read means to read the image data from the storage means; and, at different timings for each of the solid-state recording element array heads to which the image data respectively correspond, the read means to provide the read image data from the storage means. Characterized in that it has a timing control means for reading the data.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a first embodiment of the present invention,
A color copier will be described. FIG. 1 is a schematic view of a color copying machine, in which an upper part is a scanner unit 1 and a lower part is a printer unit 2.

First, the scanner section 1 will be described. FIG.
, 101 is a platen glass for placing a document,
02 is an automatic document feeder, 103 and 104 are light sources such as a halogen lamp or a fluorescent lamp for illuminating the document, 105 and 106 are reflectors for condensing light from the light sources 103 or 104, and 107 to 109 are reflections from the document. A mirror for reflecting light, 110 is a lens group, and 201 is a CCD described later. Light sources 103 and 104, reflectors 105 and 106
Are housed in a carriage 111 and mirrors 108 and 109
Is housed in a carriage 112 and the carriage 11
1. The entire surface of the document is scanned by moving the carriage 112 in the direction of the arrow at speeds v and v / 2, respectively, and the reflected light from the document placed on the platen glass 101 is imaged on a CCD 201 described later. The image data of the original is obtained as an electric signal. 113 is C
A substrate on which the CD 201 is disposed, a substrate 114 on which an image processing unit described later is disposed, and an I / F unit 115 for performing communication with an external device.

Next, the printer section 2 will be described. The printer unit 2 includes a self-scanning LED as a recording chip.
An electrophotographic printer adopting a chip, and an image forming unit including a photosensitive drum and a recording head
Four sets are provided corresponding to each MCK color, these are arranged in series at a predetermined interval, and the toner images formed on the photosensitive drums for each YMCK color are transferred onto the same recording medium conveyed at a constant speed in a superimposed manner. In this way, a so-called four-drum tandem array system for forming a full-color image is adopted.

[0015] 120, 130, 140, 150 in FIG.
Are a Y image forming unit, an M image forming unit, a C image forming unit, and a K image forming unit for forming an image for each color of YMCK, respectively. An example is described in detail. In the Y image recording unit 120, reference numeral 121 denotes a photosensitive drum serving as an image carrier;
2 is a primary charger, 123 is a recording head described later, 124
Is a developing device, 125 is a sleeve provided inside the developing device,
126 is a transfer unit. In these, first, the surface of the photosensitive drum 121 is uniformly charged by the primary charger. Next, as described below, exposure according to image data is performed by the recording head 123 to form an electrostatic latent image, and the electrostatic latent image is developed by the developing device 124 to form a Y color toner image. . Although the Y image forming unit 120 has been described above, it goes without saying that toner images of each color are formed in other image forming units.

On the other hand, the recording media previously stored in the cassettes 161 and 162 are picked up one by one by a
Paper is fed onto the transfer belt 167 by 65 and 166, and is attracted onto the transfer belt 167 by the transfer belt roller 168 and the attraction charger 169. The leading end of the recording medium adsorbed on the transfer belt 167 in this manner is detected by the paper leading end sensor 170. Such a detection signal is sent to the scanner unit 1 and is used for controlling the transmission timing of image data.

Thereafter, the recording medium is conveyed to the left in the drawing at a constant speed, and the image forming units 120, 130, 140,
YM formed as described above when passing through 150
The CK toner images are transferred to the transfer chargers 126, 136, and 14, respectively.
6 and 156, the images are sequentially transferred and superimposed on the recording medium. Transfer charger 15 in K image forming unit
6, a K color toner image is formed.
The recording medium on which all the toner images have been transferred is discharged by the discharging charger 171 and then transferred to the transfer belt 167.
In this case, the peeling charger 172 prevents image disturbance due to peeling discharge. The separated recording medium is charged by a pre-fixing charger 173 so as to supplement the toner attraction force, and then the toner image is thermally fixed by the fixing unit 174.
The paper is discharged to a paper discharge tray 175.

Next, data processing in the scanner unit 1 and the printer unit 2 will be described with reference to FIGS. 2 and 3, respectively.

In FIG. 2 showing data processing in the scanner unit 1, first, reflected light from a document is imaged on the CCD 201 by the above-mentioned mirrors 108 to 109, the lens 111 and the like, and image data is obtained as an electric signal. Note that this CCD 201 is composed of one line,
A color filter may be periodically arranged for each sensor, or a three-line RGB filter may be arranged in each line sensor for one line. Further, the filter may be an on-chip filter, or may be configured separately from the CCD. CC
The image data as an analog electric signal output from the D201 is converted into an 8-bit digital value for each of the RGB colors in the A / D converter.

Next, in a shading correction unit 202, shading correction and black correction are performed.
In the MTF correction & original detection unit 204, a connection process,
MTF correction processing and document detection are performed. That is, the splicing process is to adjust and synchronize the delay amount for each color in accordance with the reading speed of the scanner when the CCD 201 is composed of three lines, and differs from the MTF correction depending on the reading speed and the magnification. The MTF is corrected, and the document detection is to detect the size of the document on the platen glass 101.

Thereafter, in the input masking section 205, processing is performed to correct the spectral characteristics of the CCD 201, the light sources 104 and 105, and the like.

The output of the input masking unit 205 is
Selector 20 switchable with input from / F section 214
6, color space compression, background removal, and LOG conversion unit 20
7 is input to the background removal unit 215.

After the background of the image data is removed by the background removal unit 215, the black character is determined by the black character determination unit 216 to generate black character determination data, which is input to the moiré removal unit 209.

On the other hand, the color space compression & background removal & LOG conversion unit 207 performs color space compression processing, background removal processing,
A LOG conversion process is performed. That is, the color space compression process determines whether or not image data can be reproduced by the printer unit,
In the case of no, the correction is performed so as to be within the reproducible range of the printer unit. The background removal processing is to detect the background component from the image data and remove the background component. The conversion process is a process of converting image data represented by RGB luminance into image data representing YMC density by performing logarithmic conversion. This output is output to delay unit 1
At 08, the data is delayed and input to the moiré removing unit 209 to synchronize with the black character determination data from the black character determination unit 216.

After the moire is removed from the YMC image data and the black character determination data input to the moiré removal unit 209 in this manner, the magnification processing unit 210 performs a scaling process, and the UCR & masking & black character reflection is performed. In the unit 211, each processing of UCR, masking, and black character reflection is performed. That is, UCR is for generating YMCK image data based on YMC image data and black character determination data, and masking is to input a signal that is corrected to a signal suitable for the characteristics of the printer. The reflection is to feed back a black character determination signal to CMYK image data.

The image data for each color of YMCK thus generated is subjected to γ correction processing in the γ correction section 212, and is subjected to smoothing or edge enhancement processing in the filter section 213. This output is output to the printer unit 2.

Next, signal processing in the printer unit 2 will be described with reference to FIG. In FIG. 3, 301 is 2
Value processing unit, 302 to 305 are FIFO memories, 306
309 is a memory control unit, and 310 is a memory.

The image data for each YMCK color input from the scanner unit 2 is first input to the binarization processing unit 301. The binarization processing unit 301 determines that each pixel is 256 bits of 8 bits.
The image data represented by the gradation is converted into 1-bit pseudo halftone image data. For example, a well-known dither matrix method, an error diffusion method, or the like may be used. The FIFO memories 302 to 305 at the subsequent stage are for adjusting a difference between an image clock of the scanner unit 1 and an image clock of the printer unit 2.

Thereafter, the image data of each color of YMCK is transferred to the memory 31 via the memory control units 306 to 309.
0 are written in the order of input as shown in (1) of FIG. That is, one line of image data is serially written to the memory 310 in a raster fashion. In the drawing, the numbers in squares are the serial numbers of the pixels sequentially numbered from the end in one line.

The image data for each color of YMCK written in the memory 310 is stored in the memory control units 306 to 30.
9 is read out. At this time, the YMCK image data is controlled so as to be read at a timing corresponding to each color. That is, as described in the description of the printer unit 2 in FIG. 2, the image forming units of each of the YMCK colors are arranged in series at a predetermined interval in the transport direction of the recording medium, and the electrostatic latent image formed on each photosensitive drum is Since the images are sequentially transferred onto the same recording medium conveyed at a constant speed, the timing is set by the time corresponding to the distance between the image forming units, more specifically, by the time the recording medium moves between the transfer positions. This is because it is necessary to send the image data staggered. Assuming that the distance between the transfer units of the adjacent image forming units in the printer unit 2 is d and the moving speed of the recording medium is u, the M image data is read after a lapse of d / u from the reading of the Y image data. Are read out, the image data of C is read out after the elapse of the d / u time, and the image data of K is read out after the elapse of the d / u time.
Numeral 9 controls the timing of reading image data for each color of YMCK from the memory 310. Note that YM
The intervals between the CK transfer units need not necessarily be equal,
In that case, it goes without saying that the delay time is appropriately set. Also, for example, after assembling the device at the manufacturing stage,
A so-called registration adjustment in the sub-scanning direction can also be realized by measuring the arrangement interval of the YMCK transfer units and changing the readout timing for each YMCK color in accordance with the measurement result so as to finely adjust the readout timing. YMCK
The registration adjustment amounts in the sub-scanning direction for each color are stored in registers 315 to 318, respectively, and can be rewritten.

When reading the image data of each color of YMCK, the reading order is controlled as shown in FIG. That is, as described with reference to FIG. 8, since the recording elements are driven in a time-division manner in each recording chip, the driving order of the recording elements in the recording head is different from the order in which one line is serially input in a raster manner. Because. More specifically, first, image data corresponding to the first recording element in each recording chip is sequentially read out one bit at a time, and then image data corresponding to the second recording element from the end in each recording element chip is sequentially read. The data is read out one bit at a time, and the same is repeated thereafter. As described above, the function that the shift registers 91-1 to 91-56 had in FIG.
The memory 310 and the memory control unit 306 convert the function of converting raster image data input serially for lines into serial output for each recording chip.
The shift register can be omitted by providing に も to 309. In this way, the image data written in the memory 310 is controlled by the memory control units 306 to 309 so that the image data is read at a timing corresponding to each of the YMCK colors and in an order corresponding to the driving order of the recording elements in the recording head. Is what is done.

Further, when reading the image data of each of the YMCK colors, it is possible to adjust the main scanning registration. Here, the main scanning registration adjustment refers to the YMCK color image forming unit 12 of the printer unit 2.
0, 130, 140, and 150 in order to correct the installation deviation in the main scanning direction, and the toner images of each color transferred to the same recording medium are superimposed and shifted in the main scanning direction, so that the so-called color deviation is reduced. This is to prevent it from occurring. That is,
The image data can be read in a form shifted in the main scanning direction according to the main scanning registration adjustment amount required for each color of YMCK. For example, when shifting by three pixels, as shown in FIG. 4C, that is, blanks are inserted at positions 1, 2, and 3 in (2), and 3 is subtracted from all numbers. , The image data is shifted by three pixels in the main scanning direction. The registration adjustment amounts for the respective colors of YMCK are stored in registers 315 to 318, respectively, which are set, for example, after assembling the device in a manufacturing stage, and can be rewritten afterwards. Thus, the reading order can be further changed according to the main scanning registration adjustment amount.

The memory 310 stores at least a part of an image and does not need a capacity for one page of the image, and may have a capacity corresponding to a delay amount of image data for each color of YMCK. Of course, it is needless to say that a capacity capable of storing image data for a plurality of pages may be used.

The image data of each YMCK color read out as described above is stored in the recording head 12 of each YMCK color.
Latches 311 to 314 in 3, 133, 143, 153
And the image data is converted into 128-bit parallel data and input to each recording chip.

Next, the inside of the recording chip will be described in detail. FIG. 4 is an equivalent circuit of a self-scanning LED chip in which 128 light emitting elements are arranged in an array. The recording head for each color of YMCK is the self-scanning LE.
56 D chips are arranged.

In FIG. 5, L1 to L128 are light-emitting thyristors as recording elements, S1 to S128 are transfer thyristors, .PHI.I is a signal line to which pixel data corresponding to 128 light-emitting elements are serially input, ΦSS is a start signal for instructing the start of operation of this LED chip, ΦSS
S1 and ΦS2 are shift signals for sequentially shifting the elements to emit light. FIG. 6 shows these operations.
This will be described with reference to the timing chart shown in FIG.

First, the start signal ΦSS is changed from L to H (t1). At the next timing, the shift signal ΦS1 changes to H level.
The thyristor S1 for transfer is turned on (t2), and its gate voltage becomes the anode potential, that is, about 5V. Here, the recording thyristor L1 emits light by setting ΦI to L (t3), and turns off when the thyristor L1 returns to H (t4). If ΦI is kept at H, the recording thyristor L1 does not emit light (t3 to t4).

Next, by changing the shift signal φS2 from H to L, the transfer thyristor S2 is turned on (t
5). At the next timing, the shift signal ΦS1 is changed from L to H.
, The transfer thyristor S1 is turned off (t
6) Therefore, the transfer thyristor in the ON state is only S2. Here, when ΦI is set to L, the recording thyristor L2 emits light (t7), and when it returns to H, the light is turned off (t7).
8). If ΦI is kept at H, the recording thyristor L2 does not emit light (t7 to t8).

By repeating these operations, 12
The eight transfer thyristors S1 to S128 are sequentially scanned, and the recording thyristors L1 to L128 corresponding to each of the transfer thyristors emit light according to the pixel data. By arranging 56 self-scanning LED chips to form a recording head, the driving order in each recording chip is as described in FIG.

(Other Embodiments) In the above embodiment, the image data written into and read from the memory 310 by the memory control units 306 to 309 is serial data of 1 bit width. However, in order to realize higher-speed processing, it is also possible to pack image data for, for example, 8 bits and to handle the data in 8-bit parallel.

Such an example will be described with reference to FIG. FIG. 7 shows S / P units 701 to 704 and P / S units 705 to 70 before and after the memory control units 306 to 309 in FIG.
8 are inserted, and the others are configured in the same manner as in the above embodiment. In FIG. 7, FIFOs 302 to 3
In the S / P units 701 to 704, continuous 8-bit image data of YMCK 1 bit output from
Each t is packed and output as 8-bit parallel. Then, the memory control units 306 to 30
9 to the memory 310.

Further, at the time of reading, it is needless to say that the reading is performed at the timing corresponding to each recording head and in the order according to the driving order in the recording head, as in the above embodiment. The image data thus read from the memory 310 is input to the P / S units 705 to 708. Since the P / S units 705 to 708 have the same configuration, the P / S unit 705 will be described as an example. That is, 8 bits output from the memory control unit 306
The 8-bit parallel image data packed by each is sequentially input to the latches 7101 to 7156 in the P / S unit 705. The image data latched by each latch is converted into 1-bit serial data in P / S 7201 to 7256, respectively, and the selector 730 sets the P / S 7201.
The output of .about.7256 is switched one bit at a time and output to the recording head. The main scanning registration of each recording head is adjusted by adjusting the read timing from the FIFOs 302 to 305, respectively. In this way, it is possible to further increase the processing speed by packing the image data in units of 8 bits.

The memory control units 306 to 30
The configuration in which the compression and decompression processes are performed when the image data is written and read from the memory 310 by the memory 9 can also reduce the capacity of the memory 310.

Further, in the above-described embodiment, a configuration in which a light emitting element is used as a recording element and a self-scanning type LED array head having a scanning function inside a recording chip is used, but a heating element is used as another recording head. Needless to say, the present invention can be applied to an arrayed thermal head, an inkjet head, a liquid crystal shutter head, and the like.

[0045]

According to the present invention, at least a part of image data is stored in an image recording apparatus having a plurality of solid-state recording element array heads for driving a solid-state recording element in each solid-state recording element array chip in a time-division manner. The cost can be reduced by reading the image data from the storage means in an order corresponding to the driving order of the solid-state recording elements and at a different timing for each solid-state recording element array head.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a color copying machine.

FIG. 2 is an explanatory diagram of data processing in the scanner unit 1.

FIG. 3 is an explanatory diagram of data processing in the printer unit 2.

FIG. 4 is an explanatory diagram of a writing order to the memory 310 and a reading order from the memory 310.

FIG. 5 is an equivalent circuit of a self-scanning LED chip.

FIG. 6 is a timing chart for a self-scanning LED chip.

FIG. 7 is an explanatory diagram of data processing in a printer unit 2 according to another embodiment.

FIG. 8 is a driving order of each printing element in the self-scanning printing element array head.

FIG. 9 is a conventional explanatory view.

[Explanation of symbols]

 306 to 309 Memory control unit 310 Memory 123, 133, 143, 153 Recording head

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Michio Kawase 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Toshihiko Otsubo 3-30-2 Shimomaruko 3-chome, Ota-ku, Tokyo Inside the corporation

Claims (4)

[Claims] 1. A plurality of solid-state recording element array heads each including a plurality of solid-state recording element arrays in which a plurality of solid-state recording elements are arranged; and image data corresponding to each of the plurality of solid-state recording element array heads. Input means for inputting in a raster form, storage means for storing at least a part of each of the image data input by the input means, and each of the solid-state recording element array heads for storing the image data stored in the storage means Reading means for reading data from the plurality of solid-state recording elements arranged in each of the solid-state recording element arrays of each of the solid-state recording element array heads according to image data read by the reading means. An image recording apparatus having a plurality of driving units that drive in a divided manner, wherein the input unit inputs the image data in a raster form to the storage unit. The image data from the storage means is read out from the storage means in an order different from the order and in an order corresponding to the order in which the plurality of drive means of each of the solid-state printing element array heads drive the solid-state printing elements. Sequence control means for reading, and timing control means for causing the reading means to read the image data from the storage means at different timings for each of the solid-state recording element array heads corresponding to the image data. An image recording apparatus characterized by the following. 2. An image forming section having a plurality of solid-state recording element array heads and a photoconductor corresponding to each of the solid-state recording element array heads, the plurality of image forming sections being associated with respective color components. 2. The image recording apparatus according to claim 1, wherein a color image is recorded on the recording medium by sequentially transferring the respective images onto the same recording medium. 3. The image forming units are arranged at predetermined intervals in a conveying direction of the recording medium, and are controlled by the reading control unit when the reading unit reads the image data from the storage unit. The image recording apparatus according to claim 2, wherein a read timing of each of the image data is determined according to the predetermined interval. 4. The image recording apparatus according to claim 2, wherein said order control means can change said reading order in accordance with a main scanning registration adjustment amount corresponding to each of said solid-state recording element array heads.