JPS61265970A - Digital image forming device - Google Patents

Abstract

PURPOSE:To improve the quality of image edition and to speed up image formation by giving a function which forms and outputs plural original images on a sheet of paper and erasing a part on a part equivalent to the profile of each original so as to add newly a boundary line. CONSTITUTION:After an image erasure mode selecting key 53 is depressed, a ten-key 56 specifies a profile area, whereby image data in this area is forcibly set to zero in an image memory. After the counter lines of the originals to be synthesized are erased, the contour line of each original can be newly written in the image memory. At this time, after the profile area to be erased is specified through the image erasure mode selecting key 53 and the key 56, a framing mode selecting key 54 being a profile write mode selecting means is depressed. Following the erasure action of the profile area, the new contour line is written in the area.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a digital image forming apparatus that digitally reads an image of a document, stores it in an image memory, and forms an image on paper based on the contents of the image memory. Regarding.

[Technical Overview of the Invention and its Problems] This type of device optically scans the image of a document, converts it into a digital signal, and uses a laser beam to scan the image on a photoreceptor based on the content stored in the image memory. One example is a laser printer that forms a latent image and forms an image on paper using electrophotography.

In this type of apparatus, it is normal to read a document one sheet at a time and copy the image onto one sheet of paper.

By the way, if an image editing function was provided that could form and output images from multiple documents onto a single sheet of paper, the image forming operation would only be required once, speeding up processing and reducing paper consumption. This makes it possible to reduce maintenance costs.

However, until now, a digital image forming apparatus capable of performing the above-described image editing has not been provided.

In addition, when performing the above-described image processing, it is expected that the outlines of the plurality of original documents will be formed as a glaze on the paper, resulting in an unsightly copy.

[Object of the Invention] The present invention has been made in view of the above circumstances, and includes a function of forming and outputting images of multiple manuscripts on one sheet of paper, and an image corresponding to the outline of each manuscript. It is an object of the present invention to provide a digital image forming apparatus that can erase a portion and add a new boundary line.

[Summary of the Invention] The outline of the present invention for achieving the above object is to store a plurality of original images at different addresses of an image memory, and to print a plurality of original images on one sheet of paper based on the contents of the image memory. composition mode selection means for selecting an image forming operation in which images are combined and formed; contour erasure mode selection means for selecting a mode for erasing portions corresponding to the contours of a plurality of originals on the image memory; The present invention is characterized in that a contour writing mode selection means is provided for selecting a need for writing a new contour line on the image memory after the operation.

[Embodiment 1 of the Invention Hereinafter, an embodiment of the present invention will be described with reference to the drawings. This embodiment relates to a two-color laser printer equipped with an automatic document feeder.

FIG. 1 shows the external appearance of the apparatus of this embodiment, which includes an automatic document feeder (hereinafter abbreviated as ADF) 1, a scanner unit 110, which will be described later. A printer main body 100 consisting of a laser print unit (hereinafter abbreviated as LBP unit) 300;
It is composed of a control unit 400.

The ADFI is composed of a document cover 2 incorporating a document transport section 30, which will be described later, a document supply section 3, and a document tray 4. The document cover 2 is rotatable in the direction of the arrow shown in the figure by operating the handle portion 2A, so that the document can be placed directly on the exposure glass when the automatic document feed function is not used. . Further, on the upper surface of the document cover 2, a liquid crystal display (hereinafter referred to as LC) displays an image read by a scanner unit 110, which will be described later.
(abbreviated as D) 5 and a first operation panel 6 for inputting information for image editing.

The printer main body 100 includes a second operation panel 101 on the top side for inputting print information, and -
An upper cassette 321 and a lower cassette 322 for feeding paper are removably arranged on one side, and a paper discharge tray 344 is provided on the other side.

In this embodiment, the above AD, F1. Printer body 1
00 and the control unit 400 are integrated, and each member is an independent single unit, and the method of connecting them with cables, image buses, etc. is not adopted.
The space for arranging each member is minimized, and side panels and the like can be used in common, making it possible to reduce the weight and cost of the device.

Here, we will discuss the second main control block of the device of this embodiment.
This will be briefly explained with reference to the drawings. In Figure 2, the CPU
Reference numeral 401 controls the laser printer, and this CPU path line includes an LCD interface 407.401 as an interface for the various units. Serial interface 408. A scanner interface 409 and an LBP interface 410 are connected to each other. Further, the LCD interface 40
7. The scanner interface 409 and the LBP interface 410 are connected to the first color and second color image data bus lines, respectively. Further, as image processing of the first color image data outputted via the scanner interface 409, the first color page memory 4
03 and first color page memory address controller 40
Further, a second color page memory 405 and a second color page memory address controller 406 are provided for image processing of second color image data. Then, when the information for the picture am collection is input from the first operation panel 6, the first... The second color page memory address controller 404,406 is connected to the first color page memory address controller 404,406. Various image editing operations are performed by controlling the reading and editing of image data in the second color page memories 403 and 405.

Next, details of each of the above parts will be explained.

First, the details of the ADF 1 are shown in FIGS. 3, 4 (A), (
This will be explained with reference to B).

In FIG. 3, the document supply section 3 of the ADFI consists of a document placement table 10 and a separation feeding section 15.

As shown in FIG. 4(A), the document mounting table 10 has document guides 11 and 11 that are movable according to the width of various documents (eg, A5, B5, B4 size, etc.). The document guides 11.11 each have a rack 12.12 inside the document table 10. In addition, the document placement table 1
A pinion 13 is rotatably attached to the center line in the width direction of the document placed on the paper. This binion 1
3 is adapted to engage with both said racks 12.12. Therefore, when one document guide 11 is moved to match the document width, the other document guide 11 is also moved by the same distance due to the action of both racks 12.12 and the common pinion 13, and both document guides 11 always moves symmetrically with respect to the center line. Also,
A bending portion 12A is formed on one side of one of the racks 12 by being bent downward, and the movement path of this bending portion 12A includes various document widths as shown in FIGS. 4(A) and 4(B). A plurality of switches 14A at positions corresponding to.

A document width detection switch 14 is provided, which is formed by disposing 14B... Then, the plurality of switches 14A,
The width of the document placed on the original IT unit 10 is detected from the combination of ON and OFF states of 14B, . . . .

The separating and feeding unit 15 sequentially separates and feeds the originals stacked on the original document mounting table 10 one by one. A document presence/absence detection switch 16 is provided in the separating and feeding section 15, which comes into contact with the upper surface of the stacked documents and is displaced according to the number of documents. Further, there are provided a stopper 17 that comes into contact with the lower surface of the document and presses the document upward, and a feed roller 18 that is disposed opposite to the stopper 17 and that sends out the uppermost layer of the document. Separation and feeding rollers 19 consisting of a pair of rollers separate the plurality of documents fed between the pair of rollers and feed them one by one. The document supplied from the separation feed roller 19 is sent out with the supply timing controlled by the registration rollers 20. In addition, registration roller 20
A document detection switch 21 is provided at the rear stage, and this document detection switch 21 counts the number of documents passing by and detects the length of the document being passed. Therefore, the document width detection switch 14 and the document detection switch 21 automatically detect the vertical and horizontal sizes of the document.

The document transport section 30 built into the document cover 2 includes:
It is composed of an endless belt that moves over the exposure glass 111 and rollers that drive it, and conveys the original separated and fed from the separation and feeding section 15 along the exposure glass 111 to a predetermined original stopping position. It is. The separating and feeding section 15 and the document conveying section 30 convey one sheet of the document onto the exposure glass 111, and after the exposure is completed, the document is transferred to the printer main body 1.
In synchronization with the processing timing at 00, this document is ejected and conveyed to the document tray 4, and the next document is driven to be conveyed.

Further, on the upper surface of the document cover 2, the LCD 5 and the first operation panel 6 are provided.

By providing the LCD 5, which is an example of a display device that displays the image read by the scanner unit 110, it is possible to read the image and check whether the image to be copied is accurately read before starting copying of the image. can be visually recognized, and unnecessary copying operations can be prevented. Therefore, it is possible to check whether the image is tilted or whether the document reading area (described later) has been specified correctly before copying. It is possible to significantly reduce wasted paper consumption compared to conventional paper. Note that such a display device is not limited to the LCD 5, and various display methods can be adopted. Further, if it is arranged on the upper surface of the document cover 2 as in this embodiment, the operator can easily see the screen of the CD 5 and confirm the read image. in this way,
When disposed on the upper surface of the document cover 2, a flat type display is preferable, and in addition to the LCD 5, an LED display or a plasma display may be used.

Next, the scanner unit 110 in the printer main body 100 will be explained with reference to FIGS. 3, 5, and 6. This scanner unit 110 performs exposure scanning on the original on the exposure glass 111, and inputs the reflected light of the original into the photoelectric conversion section 12o'.

That is, as shown in FIG.
The mirror 113 is attached to the first carriage 116, the second mirror 114 and the third mirror 115 are attached to the second carriage 117, and the guide shaft 118
It is possible to reciprocate in the direction of the arrow shown in the figure. Then, the reflected light from the original that has been irradiated by the light N112 and scanned over the entire exposure area of the original is focused by a lens 119 and is incident on a CCD (charge coupled device) 121 of a photoelectric conversion section 120, where it is converted into image data. It is set to be converted.

Here, the control block of this scanner unit 110 will be explained with reference to FIG. Scanner part CPtJ130
is in charge of controlling this scanner unit 110,
A program memory 131 connected to the pass line stores procedures to be executed by the scanner unit 110. The carriage drive control section 132 drives and controls a stepping motor and the like to drive the first. It drives the second carriage 116, 117, the speed of which is variable according to the enlargement/reduction mode signal from the scanner section CPtJ130. This first. second carriage 1
By making the moving speed of 16 and 117 variable, the density in the document feeding direction (DI scanning direction) can be varied to enlarge the image,
It is designed to be reduced. The light source control unit 133
The exposure light source 112 is driven to emit light while the document is being read. The ADF control unit 134 drives and controls the ADF 1, and also transmits the document size to the CPU 130 based on the outputs of the document width detection switch 14 and the document detection switch 21, thereby selecting the document reading area. It is designed to be served to Furthermore, when no original remains based on the output of the original presence/absence detection switch 16, the scanner operation is terminated.

The binarization processing control unit 135 outputs a timing signal necessary for data reading to the photoelectric conversion unit 120,
Further, the digital data of 6 bits per dot outputted from the photoelectric conversion section 120 is subjected to binarization processing.

The binarized image data is sent to the scanner interface 409 via the main control unit interface 136, and the first. It will be transmitted to the second color image data bus. The photoelectric conversion unit 120 includes the CCD 121, an amplifier 122 that amplifies the output thereof,
It is composed of an A/D converter 123 that performs analog-to-digital conversion. Then, the light emitted from the light source 112 and reflected by the first to third mirrors 113, 114, 115 enters the CCD 121 through the lens 119, and the charge accumulated in the CCD 121 is amplified by the amplifier 122. It is designed to be digitally converted by an A/D converter 123. Note that the output of the A/D converter 123 is, for example, 6 hits/dot. Furthermore, in this photoelectric conversion section 120, the density in the n1 scanning direction is variable depending on the enlargement/reduction mode, whereas the clock speed corresponding to each dot is constant, and The density (corresponding to the direction) is also constant (for example, 16 shoes/shoe).

Note that enlargement and reduction of the image in the main scanning direction will be described later. Further, main timing signals during a document reading operation in this scanner unit 110 are shown in FIG. In the figure, [H3YNOJ is a synchronization signal for each line in the n1 scanning direction, and rDATJ indicates data. For example, during reading using eight data buses, binarized data is output in units of 8 bits. rsTBOJ is a strobe signal of the rDATJ, and rVsYNOJ indicates that the sub-scanning direction is in the document reading area.

Next, the LBP unit 300 will be explained. In FIG. 3, reference numeral 301 is a photoreceptor for recording information with a laser beam, and around this photoreceptor 301, first chargers 302. First developer 303. Second charger 30
4. Second developer 305. A static elimination lamp 306 and a transfer charger 307 for increasing the peeling efficiency. A peeling charger 308, a cleaning device 309, etc. are arranged.

Further, 310 is a laser scanner unit for scanning, modulating, and recording two laser beams a and b on the photoreceptor 301. The laser beam a emitted from the laser scanner unit 310 is reflected by a first reflecting mirror 311 and is directed from almost directly above the photoreceptor 301 to the first charger 302 and the first developer 303. The photoreceptor 301 is irradiated with a first exposure section 350 between the two. On the other hand, the laser beam b is the second one.
reflected by third reflecting mirrors 312 and 323, respectively,
The light is irradiated onto the photoreceptor 301 at a second exposure section 351 between the second charger 304 and the second developer 305 .

As shown in FIG. 7, the laser scanner unit 310 includes a first. a second laser diode 314,315; The laser beams a and b emitted from the second laser diode 314 and 315 are arranged at right angles to each other so that the optical path of the laser beam a is parallel to the laser beam b. A bending prism 318 and a polygon mirror 319 that scans the laser beams a and b, respectively.
and an f/theta lens 320 placed after the polygon mirror 319, as shown in FIG.

Then, when the laser drive circuit (not shown) operates, the first . Turn on the emission of laser beams a and b from the second laser diodes 314 and 315.

OFF and the amount of light are controlled, and these laser beams a and b are transmitted through collimator lenses 316, 317 and prism 3.
18 to one side of the polygon mirror 319,
Here, it is scanned in the main scanning direction. The laser beams a and b pass through the f/θ lens 320 to the first
reflection mirror 311 or the second. Third reflective mirror 312
．． 313 and exposes the surface of the photoreceptor 301 to form an electrostatic latent image. This electrostatic latent image includes the first image. Second
Developers of different colors are supplied and visualized by the developing devices 303 and 305 (this operation will be described in detail later), and the upper cassette 321 or the lower cassette 3
This image is transferred onto the paper fed from 22.

Here, the arrangement of the exposure section with respect to the photoreceptor 301 will be explained. Since the device of this embodiment is a two-color laser printer, there are first and second laser printers in two locations. A second exposure section 350, 351 is provided. The angle θ between the direction of beam incidence on the photoconductor 301 to the first exposure section 350 and the direction of beam incidence on the photoconductor 301 to the second exposure section 351 is
(See FIG. 3) is set at an acute angle. Second exposure sections 350 and 351 are arranged. The reason for this arrangement is as follows. That is, since various parts must be arranged around the photoreceptor 301 as described above, the first. If the second exposure parts 350 and 351 are arranged far apart (when the beam intersection angle θ is an obtuse angle), the space for arranging other members becomes narrower. For this,
The drum diameter of the photoreceptor 301 must be increased to secure space, resulting in a larger device. Therefore, in order to effectively utilize the space around the photoreceptor 301, the arrangement as in this embodiment is preferable. Furthermore, by arranging it in this way, the first. The second developing units 303 and 305 can be configured to have substantially the same shape, and cost reduction can be achieved by using common parts. In addition, in order to develop the second color, after the development is performed in the first developer 303, the second color is developed.
Although it is necessary to perform recharging using the charger 304, it is preferable to perform recharging as soon as possible after the first color development. Therefore, the arrangement of the exposure portions according to this embodiment is advantageous in that recharging can be performed quickly.

Furthermore, since the laser beams a and b must have the same optical path length, the first. By arranging the second exposure sections close to each other, it becomes easy to design such optical path lengths to be the same. Also, the data of the first color is exposed,
When printing second color data in the vicinity of the developed area, it is necessary to wait for the first color data exposed area on the photoreceptor 301 to rotate to the second exposed area, and the time during this time is The deviation Δt is determined by the angle θ and the angular velocity ω[deo/5e
cl, Δ becomes -θ/ω[5ecl. Therefore, in order to reduce the time difference Δt, it is advantageous to reduce θ.

Next, this first. It is preferable that the second exposure portions 350 and 351 be provided in the upper half circumferential region A of the photoreceptor 301, as shown in FIG. 8(A). The reason for this is that the transfer charger 307, which is placed at a position facing the exposure section, can be placed below the photoreceptor 301. In this way, the paper onto which the image is transferred can be transported using its own weight, and the structure of the transport mechanism can be simplified.

If the exposure section is arranged in the lower half of the photoreceptor 301, the transfer charger, etc. will be arranged in the upper half of the photoreceptor 301, and in this case, the paper must be conveyed while being held by a belt or the like. However, such a configuration is very difficult and also complicated, which is undesirable. Next, by arranging the exposure section in the upper half of the photoreceptor 301, the first reflecting mirror 311 as shown in FIG.
The mirror surface of can be directed downward. Therefore, dust and the like will not adhere to the mirror surface due to its own weight, and since dust adhesion to the mirror surface has a large effect on image quality, this is also advantageous. If the exposure section is placed on the lower half of the photoconductor 301, the mirror surface of the reflection mirror 352 must face upward as shown in FIG. This is complicated and undesirable.

Next, a paper feeding system and a paper ejection system will be explained with reference to FIG.

The upper set 321 includes an upper paper feed roller 323 for taking out sheets of paper one by one from the cassette, an upper paper out switch 324 for detecting when there is no paper in the cassette, and an upper paper feed roller 324 for detecting the paper size of the upper cassette 321. The upper cassette size detection switch 325 detects the size of the upper cassette. Similarly, the lower cassette 322 also has a lower paper feed roller 326. A lower paper out switch 327 and a lower cassette size detection switch 328 are provided.

Furthermore, above the upper cassette 321, there is provided a manual feed guide 330 into which paper can be inserted manually, a manual feed switch 331 detects the paper inserted from this manual feed guide 330, and a paper whose insertion is confirmed by this switch is provided. A manual feed roller 332 for conveying the paper is arranged.

This upper cassette 321. Registration rollers 340 are arranged at the forward end of the conveyance path for sheets fed from the lower cassette 322 or the manual feed guide 330. The registration roller 340 synchronizes the image developed on the photoreceptor 301 with the paper, and sends the paper to the transfer charger 307. This transfer charger 30
The paper on which the image has been transferred in step 7 is transferred to the peeling charger 30.
8 and is discharged forward by the suction belt 341.
Furthermore, after the image is fixed by heat and pressure in a fixing device 342, it is delivered to the paper ejection tray 344 by a paper ejection roller 343.

Next, a two-color printing operation by the LBP unit 300 will be explained.

The process of a two-color laser printer is to form a two-color toner image on the photoreceptor 301 during one rotation of the photoreceptor 301, and transfer this to paper (N sheets of paper). That is, the third
As shown in the figure, charging and developing devices are arranged around the photoconductor 301 for each color, and after forming a two-color toner image on the photoconductor 301, the transfer charger 307 transfers the two-color toner image onto the paper. is transferred at once, and the toner image is fixed by a fixing device 342, thereby completing two-color printing.

On the other hand, untransferred toner on the photoconductor 301 is collected by a cleaning device 309, and after cleaning the photoconductor 301, the next print cycle is started.

In this embodiment, in order to obtain a two-color printed image by rotating the position of the photoreceptor 301, a non-contact developing method is adopted. This is because in a contact development method such as a conventional magnetic brush development method, the first toner image initially formed on the photoreceptor 301 as shown in FIG. 9(A-) is It may be scraped off by the second developer as shown in Figure 9 (
As shown in C), the first. The second toners sometimes intermingled and adhered to the photoreceptor 301. Furthermore, as shown in FIG. 10, the first toner that is transported while adhering to the photoreceptor 301 sometimes gets mixed into the second developing device 305, resulting in a significant deterioration of image quality.

Also, as a non-contact development method, there is a method using a magnetic component developer, but since it contains blackish magnetic powder, it is not possible to obtain color toner with high saturation, making it unsuitable for multicolor printing. be.

Therefore, in this embodiment, a two-component developer in which iron powder carrier and non-magnetic toner are mixed using a magnetic brush is used. That is, as shown in FIG. 11, a two-component developer 355 is stirred by a mixer 356 and a magnetic brush roll 357 to be triboelectrically charged. Then, due to the magnetism of the iron powder carrier, the two-component developer 355 is attracted to the magnetic brush roll 357 and conveyed by rotation. The two-component developer 355 forming a magnetic brush is regulated to an appropriate layer thickness by a doctor blade 358, and is rubbed against a non-magnetic developing roll 359. and,
By applying a DC bias voltage 360 between the magnetic brush roll 357 and the developing roll 359, only the non-magnetic toner 355A in the two-component developer 355 is electrostatically separated onto the developing roll 359. This developing roll 359 is connected to the photoreceptor 301 by a gap adjustment ring (not shown).
An appropriate gap (for example, 200 μm) is maintained between the two. Furthermore, since the non-magnetic toner 355A is positively charged by RFL friction with the iron powder carrier, the non-magnetic toner 355A conveyed by the developing roller 359 is
Development is performed by flying onto the electrostatic latent image pattern whose potential is attenuated on the photoconductor 301. Note that the two-component developer 355 that has been rubbed by the developing roll 359 is scraped off by a scraper 361 and used for another development. Further, the toner concentration of the two-component developer 355 is detected by a toner concentration sensor (not shown), and based on this detection, toner is replenished from a toner hopper (not shown) to maintain a constant toner concentration. There is.

Next, Figure 12 (A) shows how to prevent color mixing during multicolor printing.
-(D) and FIGS. 13(A)-(D). FIGS. 12(A) to 12(D) are schematic illustrations showing the occurrence of color mixture. The photoreceptor 301 is uniformly charged (Fig. 12 (
When the first exposure is performed, the surface potential of the exposed area is attenuated to Vs, the first toner is attached thereto, and the first development is performed (as shown in FIG. 12(B)). After that, when the second exposure is performed, this exposed portion is also attenuated to the surface potential Vs (
(Illustrated in FIG. 12(C)). If the second development is performed in this state, the second toner will develop the first exposed area as well as the second exposed area, resulting in a mixed color (as shown in FIG. 12(D)).
. This development occurs because the potential of the first exposed portion is lower than the development start potential during the second development.

In order to solve this color mixing problem, it is necessary to restore the surface potential of the first exposed portion to the surface potential before exposure. At this time, it is necessary to prevent the surface potential of the unexposed area from changing. In order to satisfy these contradictory factors, a corotron corona discharge charger that superimposes alternating current and direct current voltages is used as the second charger 304 in this embodiment.

Figure 13 shows the color mixing prevention process using this charger (
This will be explained with reference to A) to (D).

(1) The photoreceptor 301 is uniformly positively charged by the first charger 302 (see FIG. 13(A)).

(2) First exposure is performed using the laser beam a from the first laser diode 314, and the first toner is attached to the exposed area of 1 at the surface potential (2), and the first development is performed (FIG. 13(B)
reference).

(3) Recharging is performed with the second charger 304, and the surface potential of the first exposed area is set to a potential ■s that is approximately equal to the surface potential of the unexposed area.
2 (see Figure 13(C)).

(4) Second exposure is performed with the laser beam b from the second laser diode 315, second toner is attached to this second exposed area, and second development is performed (see FIG. 13(D)).
. At this time, since the surface potential of the first exposed portion is higher than the development start voltage during the second development, the above-mentioned color mixture does not occur.

Next, details of laser scanning in the laser scanning unit 310 will be explained. FIG. 14 is a schematic perspective view illustrating laser scanning of the photoreceptor 301 from the laser scanner unit 310. It should be noted that each member shown in the same figure is given the same reference numeral as in FIG. 3 or FIG. 7, and detailed explanation thereof will be omitted. In this laser scanning, there are two problems that greatly affect image quality. That is, the laser beam a from the first laser diode 314
The scanning start point in the main scanning direction on the photoreceptor 301 is set at 81.
．． The scanning end point is El, and the second laser diode 31
The starting point of scanning by laser beam b from 4 is 82. If the scanning end point is El, there are problems shown in FIGS. 15(A) and 15(B). FIG. 15(A) shows both scanning starting points S1. S
2 are not on the same line and produce a difference d. This is the first. Second laser diode 314.31
This occurs when the laser beams a and b from 5 are not parallel before entering the polygon mirror 319.

On the other hand, FIG. 15(B) shows the first. Second laser beam 31
4.315 indicates that the scanning lengths of the laser beams a and b in the main scanning direction are different from those of Ill and J2. This is the laser beam a after passing through the f/θ lens 320.
, b occurs when there is a difference in the exposed area until the photoreceptor 301 is exposed.

This embodiment is configured as follows in order to solve the above two problems.

First, the input/output relationship between the LBP unit 300 and the LBP interface 410 is shown in FIG.
This will be explained with reference to FIG. Signals between the LBP unit 300 and the LAP interface 41o are broadly classified into control signals and image-related signals.

As a control signal, the LBP interface 410
There are command signals such as print commands sent from the LBP unit 300 to the LBP interface 410, and status signals such as a print ready signal indicating the status of the LBP unit are sent from the LBP unit 300 to the LBP interface 410.

As an image-related signal, L is transmitted from the LBP unit 300.
For the BP interface 410, as shown in FIG. 17, there are a video clock signal for the main scanning direction and a horizontal synchronization signal for the sub-scanning direction, which are respectively issued in correspondence with the print area. The first one corresponds to the signals of two colors. 2nd signal, 1st
．． This is the second horizontal synchronization signal. Further, the LBP interface 410 is connected to the first. a second video clock signal; a first video clock signal; Based on the second horizontal synchronization signal, the first . A second video data signal is output.

The control system block of the LBP unit 300 includes:
Said 1st. a second video clock signal and a first video clock signal; A second horizontal synchronizing signal is generated, and the first horizontal synchronizing signal is generated. It has a print control section 370 (details will be described later) that drives the first and second laser diodes 314 and 315 based on the second video data signal. This print control section 370 is connected to an I10 port 372 of a microcomputer 371. In addition to the print control unit 370, the microcomputer 3A1 includes various sensors necessary for printing operations,
The I10. connected to an input/output device such as a motor. j? −
372, L8P, ROM 374 for storing the operation program of y-to-300, and RAM 37 for storing data.
5, a timer 376 that generates a clock, and a scanner CPt 1373 that controls each of these parts.

Next, an example of the printing control section 370 will be explained with reference to the block diagram shown in FIG. 18 and the timing chart shown in FIG. 19. FIG. 18 shows that one photodetector 200 detects the scanning start point of the laser beams a and b, and the two laser beams a and b are applied to the photoreceptor 3, which is one of the problems mentioned above.
This circuit corrects the positional deviation of the scanning start position Et to 01 and E2.

In FIG. 18, the photodetecting element 200 detects a laser beam a.
The horizontal synchronization detection signal S1, which is the output thereof, is connected to the set terminal of the flip-flop 201. Q of this flip-flop 201
The output is the line start signal S2 from the quaternary counter 20.
Input to reset terminal R of No.2. Further, the oscillation output 83 (1/4 clock corresponding to 1/4 dot) of the oscillator (O20) 203 is input to the clock terminal of the quaternary counter 202. The clock signal S4, which is the Q output of the quaternary counter 202, is used as a video clock, and the horizontal synchronization detection signal S4 is used as a video clock.
1, and is output with an accuracy of one clock (corresponding to one dot) obtained by dividing the frequency of the oscillation output S3 by four.

On the other hand, the line start signal S2, which is the Q output of the flip-flop 201, is sent to the counters 204, 205A, 20
Input to reset terminal R of 6A, and also input to quaternary counter 2.
The clock signal S4, which is the output of 02, is sent to the counter 205B.
, 206B. The counter 204 is a monostable timer, and the counters 205A and 206A are presettable programmable counters. Then, the counter 2
The output S5 of 04 is a sample timer signal that is periodically generated in response to the horizontal synchronization detection signal S1 for the purpose of detecting the horizontal synchronization position and generating sample pulses for the laser light amount stabilizing circuit. In addition, the counter 20
5A is the left margin in the horizontal direction, the counter 20
6A is a counter for setting a horizontal write margin.

In addition, the output S6 of the counter 205A is output to the inverter 207.
A is input to one input terminal of the AND gate 208A, and the output S7 of the counter 206A is input to the other terminal of the AND gate 208A. Then, an AND gate 2 in which the output of this AND gate 208A and the output S4 of the quaternary counter 202 are operated by two people.
The output S8 of 09A is output to the LBP interface 410 as the first video clock signal.

Further, an AND gate 21OA is provided which handles the output of the AND gate 208A and the first video data signal by two people. The output of this AND gate 210A,
The output of the OR gate 212A which combines the output S5 of the counter 204 with the signal via the inverter 211 is provided as the loser drive signal S3.

Then, this first loser drive signal S9 is transmitted to the first laser diode 3 via the first loser drive circuit 213A.
14 to emit light.

On the other hand, the drive control system that performs the second packet centering includes the counters 205A, 206A and the inverter 207Δ shown in FIG.
, the AND gates 208A, 209A, 21OA, the OR gate 212A, and the suffix rAJ of the loser drive circuit 213A have the same configuration as the suffix "BJ".The counters 205B and 206B are programmable, respectively. , output of counter 205B]
Set the horizontal left margin by S + o,
The horizontal write margin is set by the output S++ of the counter 206B. Further, the second video clock signal S12 and the second video drive signal S13 are sent to the counter 2 in the same manner as in the case of the first package.
04. Signal S of counter 205B and counter 206B
s, Sho, and So.

Note that the power C controllers 205A and 206A, the inverter 207A, and the inverter 207A for outputting the first video clock signal @S8,
The AND gates 208A and 209A constitute a first video clock generation circuit 420. Further, the counters 205B and 20 for outputting the second video clock signal S12
6B, inverter 207B, AND gate 2088.2
09B is the second video clock generation circuit 421.

In this way, in this embodiment, two types of laser beams a
, b can be achieved with one photodetector element 200. Conventionally, two types of laser beams a,
Since the horizontal synchronization detection of b is performed using two independent photodetecting elements, the number of parts increases and position adjustment of the two photodetecting elements takes time and is complicated. Therefore, according to this embodiment, it is possible to reduce the cost of the device by reducing the number of parts, and it is also possible to improve the ease of assembly without requiring complicated adjustment work.

In addition, as shown in FIG. 10<A), the laser beams a, b
If a deviation d occurs at the scanning start point S1.82 of the first. This can be easily corrected by the second video clock generation circuits 420 and 421. That is, by varying the preset value of either the counter 205A that sets the horizontal left margin of the first color laser beam a or the counter 205B that sets the left margin of the second color laser beam b, the first This deviation d can be corrected by delaying the scanning start point E1 of the color laser beam a or by advancing the scanning start point E2 of the second color laser beam b.
can be eliminated. Therefore, polygon mirror 319
This deviation d can be easily corrected without requiring complicated optical adjustments to make the laser beams a and b accurately parallel beams before they are incident on the laser beam.

Next, the first section regarding the sub-scanning direction. The configuration for outputting the second horizontal synchronization signal S17.820 will be briefly described with reference to the block diagram shown in FIG. 18 and the timing chart shown in FIG. 20. A counter 215A is configured to output the first horizontal synchronization signal S17.

216A, inverter 217A, AND gate 218A
, 219A are provided. Similarly, as a configuration for outputting the second horizontal synchronization signal 820, the counters 215B and 21
6B, inverter 217B, AND gate 2188,2
19B is provided.

Here, to explain the output of the first horizontal synchronization signal S17, the counters 215A and 216A are programmable counters that can be preset, and the counter 21
The counter 5A sets the top margin, and the counter 216A sets the bottom margin. and,
The page top signal Se4 is input to the gate terminals G of the counters 215A and 216A, and the line start signal S2, which is the output of the Philips block 201, is input to the clock terminal Cp. Then, the operation after this is the first one.
The first horizontal synchronization signal SL7 can be created in the same manner as the video clock signal S8. The same applies to the creation of the second horizontal synchronization signal S+o.

Next, another configuration example of the printing control circuit 370 that can also correct the mismatch in scanning length shown in FIG. 10(B) will be described with reference to FIGS. 21 to 23. FIG. 21 is a block diagram showing another example of the configuration of the print control circuit 370. The block shown in this figure is different from the block shown in FIG. 18 in that a quaternary counter 220 and a selector 230 are added. It is. Then, the quaternary counter 202
The first clock signal S4 is generated with an accuracy of one clock, whereas the newly added quaternary counter 22
0 generates a second clock signal 84' which is synchronously stretched by 1/4 clock, and this locking signal reduces the number of video clockers in total and apparently stretches the beam with a short scanning length. ing. The selector 100 is the first. Second clock signal S4
, 84' are input, and the second clock signal 84' is selected and output for a beam having a short scanning length.

In this embodiment, the scanning length correction means 242 that corrects the scanning length of the beam in this manner corrects the scanning length of the beam in accordance with the scanning length of the beam. Second clock signal S4. Reference clock generation circuit 234 that outputs S4' as a reference clock
Then, this reference clock is used as the first clock. It is composed of a selector 230 that selects and outputs to the second video clock generation circuits 240 and 241.

Here, the details of the quaternary counters 202, 222 and the selector 230 in the scanning length correction means 242 are explained in the second section.
This will be explained with reference to FIGS. 2 and 23. In FIG. 22, 221 is a presettable N-ary counter, which counts the oscillation output S3 of the oscillator 203 after the horizontal synchronization detection signal S1 is output from the photodetector element 220. The preset value can be arbitrarily set using, for example, a dip switch 222 shown in the figure. Shift register 223, Nantes gate 224. Noah gate 225 and inverter 22
6 is a gate circuit that provides a predetermined operation to the N-ary counter 221. Clock terminal C of shift register 223
The oscillation output S3 is input to P, and the line start signal S2 is input to the reset terminal R, and the Qo and Qt ratio outputs are input to the Nantes gate 224, and the Q2 output is input to the N-ary counter. 221 CI.

Input to CE terminal. Further, the output of the NOR gate 224 and the output of the inverter 226 are inputted to a Nandt gate 225, and the output of this Nandt gate 225 is inputted to the LD terminal of the N-ary counter 221. still,
The inverter 226 receives a carry from the Co terminal of the N-ary counter 221. Here, as shown in FIG. 23, after the line start signal SS2 is input to the register 223 and the reset terminal R of the N-ary counter 221, the oscillation output S3 is input to the register 223. N-ary counter 221
When input to the clock terminal Cp of the NOR gate 225, the output S21. The Q2 output SZ2 of the register 221 is input to the N-ary counter 221 as the signal shown in the figure, and the carry output SZ3 is input to the Co terminal of the N-ary counter 221.
will occur. And this carry output 82
3 is a JK-type rough flip-flop or lower JK-F which is inverted via the inverter 226 and constitutes a quaternary counter.
- abbreviated as F) 227.228 one JK・F-F
It is designed to input to the terminal J of 227. still,
The J terminal of the other JK-F-F228 is always at a high level. Here, this JK-F-F227.2
28 performs a toggle operation at the rising edge of a clock input when both terminals J and J are at a high level, and maintains the previous state when both terminals J and J are at a low level. And the reset terminal R of this JK-F-F227, 228
Since the line start signal S2 is input to the line start signal S2, the JK-F-F227.228 starts operating in synchronization with the input of the line start signal $2, and the JK-F-F227.
-The oscillation output S3 which is the clock input of F-F227
will be divided into four. And the JK-F-F2
When both terminals J and 27 are at low level (when a carry occurs in the N-ary counter 221), the oscillation output S
The toggle operation is interrupted by one clock of 3 (corresponding to 1/4 dot). As a result, the simulated JK-F-
As shown in Figure 23, when the pulse interval during normal operation is set to "1", the output of F228 is r when a carry occurs.
It becomes 11/4 J, and the draw is extended by 1/4 clock.

On the other hand, the counter 202 has two JK-F-F202
A, 202B, its J.

Since the K terminal is always at a high level, its Q output becomes a clock whose frequency is accurately divided by four as shown in FIG.

A selector 230 inputting the outputs of both quaternary counters 202 and 220 is connected to AND gates 231 and 234 inputting the outputs of the quaternary counter 220 and the quaternary counter 20.
It has AND gates 232 and 233 which input the outputs of 2 and 2. The other input of the AND gates 231 and 233 receives a high level when the switch 235 is "open", and receives a low level when the switch 235 is "closed". On the other hand, the other input of AND gates 232 and 234 causes switch 235 to
When the switch 235 is set to "open", a low level is input by the action of the inverter 236, and when the switch 235 is set to the "leap" position, a high level is input. Further, there are provided an OR gate 237 that allows two people to input the outputs of the AND gates 231 and 232, and an OR gate 238 that allows two people to generate the outputs of the 7 AND gates 233 and 234.

Therefore, when the switch 235 is set to rRJ,
The OR gate 237 outputs the second clock signal 84' which is the output of the quaternary counter 220, and the OR gate 237
8 outputs the first clock signal S4 which is the output of the quaternary counter 202. In addition, the switch 23
5 is "closed", the OR gate 237 outputs the first clock signal S4, and the OR gate 238 outputs the second clock signal 84'.

If the second clock signal 84' is used as a video clock for a laser beam with a short scanning length by switching the switch 235, the scanning length on the photoreceptor 301 can be increased.

For example, the normal scan length is 200. Correction when one of the laser beams w is 1M shorter will be explained. When the resolution is 12 lines/line, in order to correct the scanning length difference of 1 line, the video clock signal of the short scanning length beam needs to be stretched by 12 pulses per 2400 pulses (200×12). Here, since the oscillation output S3, which is the clock input of the N-ary counter 221, is a 1/4 video clock,
The preset value of the N-ary counter 221 may be set to a value such that one carry occurs every 50 counts.

In this way, the difference in scanning length as shown in FIG. 10(B) can be corrected. Note that the preset value of the N-ary counter 221 is the scanning length of the beam.

The scanning length difference can be corrected by setting it appropriately according to the scanning length difference between the two beams and the resolution.

Next, various image editing functions in this device will be explained.

First, the above 1. An example of the second operation panel 6.101 will be described with reference to FIG. 24.

the first operation panel 6 for inputting image editing information;
is equipped with various keys as shown in FIG. The composition mode selection key 50 is a key for selecting a mode in which images of a plurality of documents sequentially supplied from the ADF 1 are composited onto one sheet of paper and output. In addition, when ADFI is not used, a mode is selected in which images of originals placed one after another on the exposure glass 111 are combined onto one sheet of paper and output. Further, a first numeric keypad 56 is provided as a document number input means for inputting the number of document sheets whose images are to be combined on one sheet. Incidentally, the reference numeral 57 in the figure is a sheet number display that displays the number of original sheets inputted using the first ten-key pad 56. The image extraction mode selection key 51 is a key that is selected when extracting not the entire image of the document but a portion of the image and copying it onto a sheet of paper. As a means for specifying the extraction area of the document, for example, the coordinates of the extraction area are inputted via the first numeric keypad 56 using the coordinates 5A marked around the LCD 5. By the way, when the above-mentioned compositing mode is selected by the above means, it is possible to specify the extraction area for a plurality of documents, and also to specify division of the extraction area for one document. The output position designation mode selection key 52 is a key for selecting a mode for designating a position at which a document image is formed on a sheet fed from the upper cassette 321 or the lower cassette 322 or the like. The image forming apparatus designation means for the sheet includes the coordinates 5A and 5A.

The first numeric keypad 56 is also used.

The image erasure mode selection key 53 is a key that is selected when partially erasing an image on a document. Particularly, when the combination mode is selected, this is effective for erasing the outlines of a plurality of documents. Note that the coordinates 5A and the first numeric keypad 56 are used as means for specifying the image erasure area.

The framed mode selection key 55 is a key that is selected when adding a new outline after the outline of the document has been erased by selecting the image erasing mode. The pagination mode selection key 55 is a key selected when adding pages to a sheet of paper. In this embodiment, there are two types of page attachment modes; one is a mode in which pages are attached in the order in which the originals are input, corresponding to the images of a plurality of originals formed on one sheet of paper during the composition mode. The other mode is a mode in which pages are attached in the order in which paper is output. When selecting the former mode, after pressing the page mode selection key 55,
"Input order" selection key 55A is pressed. When selecting the latter mode, after pressing the pagination mode selection key 55, the "output order" selection key 55B is pressed.

Next, the second operation panel 101 for inputting print information and the like will be explained. In FIG. 24, 150 is a start key for starting a copying operation, and 151 is a second numeric keypad, which is an example of a sheet number input means for inputting the number of sheets to be copied for the same original image. This ¥1
The number of sheets entered using the numeric keypad 151 of 2 is displayed on a sheet number display 152, and a cancel key 153 for canceling the number of sheets is provided. 154 is a cassette selection key for selecting the upper cassette 321;
is a cassette selection key for selecting the lower cassette. 1
Reference numeral 56 denotes an LCD display for displaying various states of the printer, including the standby state of the printer.

It is designed to schematically display information such as paper size information, occurrence of jams, toner replenishment, etc.

Further, 157 is an auto magnification mode selection key, and when this key is pressed, the original image is automatically enlarged or reduced based on the size of the original image and paper. Reference numeral 158 is a magnification specifying key, and by selecting a numerical value with the second numeric keypad 151 after pressing this key, a desired enlargement or reduction magnification can be set. Reference numeral 159 is a key for selecting a reduction or enlargement mode in accordance with a predetermined original size or paper size.

Next, a page memory address controller that performs various image editing operations based on input information to the first operation panel 6 will be described. In this embodiment, in order to perform two-color image formation, the first color is used.

2nd color page memory address controller 404°40
6, both of which have the same configuration. FIG. 25 is a block diagram showing an example of the first color image memory address controller 404.

This page memory address controller controls the address and read/write signals of the page memory.

First, page memory address control will be explained.

The page memory address controller shown in this example is as follows:
This is provided to efficiently use page memory. The address of the page memory is usually determined by applying a read/write signal as a count in the main scanning direction and a horizontal synchronization signal (H3YNC) signal as a count in the sub-scanning direction. by the way,
When specifying page memory addresses using such control, a good number of page memory divisions in the main and sub-scanning directions is 1024, 2048.4096.8192.・
...and is a multiple of 2. However, the number of main scanning directions actually used is rarely close to the above number, and in the case of this device, the main scanning width is approximately 5000 bits (approximately 625 bytes), and the sub-scanning width is approximately 7000 bits (approximately 625 bytes). (approximately 875 bytes).

Therefore, to satisfy this address space, 8192X
An address space of 8192 bits (1024 bits x 1024 bytes) is required, and both the memory element and the counter element are wasted.

In order to minimize the above-mentioned waste, the device of this embodiment has XW (
TP) register 423. Adder/subtractor 424° latch circuit 4
25. An address control block consisting of an address counter 426 and an address transceiver 427 is provided.

Here, XW is a value corresponding to the width of the output paper (width in the main scanning direction), and based on the outputs of the upper and lower cassette size detection switches 325 and 328, the
1 determines this XW and transmits the XW (T
P) Set in register 423. Also, set the read/write start address (TP) in the same way as XW(TP
) register 423, the above address control block inputs the H8YNC signal to TP+
The number XWxN (N is an integer) is accessed, and the start address in the main scanning direction is accessed.

Also, when a read signal (PRDC) or a write signal (PWTC) is input from the image bus to the line control/return clock generator 437 via the clock receiver 440, a write/read clock synchronized with the read signal and write signal is generated. is generated, and the addresses in the main scanning direction are sequentially updated by this clock. By specifying addresses in this manner, the addresses become continuous one-dimensional numbers with almost no spaces, and the number of memory elements and counter elements can be kept to a minimum. Note that when a composite mode in which multiple original images are formed on one sheet of paper is selected, a start address (TP) is set at a predetermined position according to each original.
All you have to do is set .

Next, a description will be given of a block that controls partially reading data from the page memory or partially rewriting data. For this purpose, the XN register 430. XN counter 431. YN register 432 and YN counter 43
3 is provided.

XN and YN are values in the main scanning direction and sub-scanning direction that specify the area on the image memory, respectively, and these values are CPtJ.
The XN register 430 . It is set in the YN register 432. The values of XN and YN are set in the XN and YN counters 431 and 433 that count the read/write clock, and when the XN counter 431 counts the read/write clock by XN, it outputs a carry and performs a carry in the sub-scanning direction. conduct. And XN, YN counter 43
If a carry is output from 1.433, it means that the access range specification has been completed. At this time, a page end signal (PG
END) is output to the image bus, and all data in the access range is cleared.

Note that in this embodiment, it is possible not only to erase specific data in the page memory, but also to write specific data. At this time, after setting TP, XN, and YN to specify the data writing position in the same manner as above,
DMA (Direct Memory Access) shown in the figure
By programming the data address and data length at which data to be written is stored in the controller 411 and enabling the DMA operation, this data is written onto the page memory. Note that the data to be written is stored in the program memory 402.

In this case, the data may be a character, a symbol, or a specific pattern, such as a page code or an outline of a document.

Mask register 434. The mask counter 435 is used to invalidate a certain range of image data in the page memory, and when an address corresponding to a predetermined range is set in the mask register 434, the data in that range is forced to zero. It has become so.

Address register 436 is provided to allow CPtJ 401 to recognize the address currently being accessed by this page memory address controller, and this address is used by data transceiver 420 . C.P.
The data is transferred to the CPU 401 via the U bus.

Note that the line control receiver 438 receives a line synchronization signal (NX
LIN), bus control receiver.

Reference numeral 441 inputs a data high enable signal (DHENB) and an image disable signal (IMD Is) and transfers them to the line control I/clock generator 437.

Next, the page memory as an image memory will be explained. The first color and second color page memories 403 and 405 have a configuration as shown in FIG. This page memory 403 can store 1 or 2 Mbytes of data according to the address signal output from the page memory controller 404. As a memory element, 64 256-bit dynamic RAMs are used, and the memory space is 2M bytes. The bus commonly used is the image bus, which is the page memory address controller 404, 406 . Image data controlled by each control signal from the print control section 370 and the like is read/written from this image bus via a data buffer 403A. In addition, the above-mentioned D
Data buffer 4 is sent from the CPU bus only in MA mode (a mode used when writing page codes or the outline of a document, etc.).
Data is input via 03B.

Next, the configuration of the scanner interface 409 will be explained with reference to FIGS. 28 to 30.

This scanner interface 409 is connected to the CPU 401
In addition to transmitting control signals from the CPU to the scanner unit 1-110, the status of the scanner unit 110 is transmitted to the CPU.
401 side, and also reduce the read image data.
It plays the role of enlarging the data and transmitting it to the page memories 403 and 405. That is, as shown in FIG. 28, an address signal is input from the CPU bus to the address code converter 450, data is input to the bus transceiver 458, and various data are input to the basic command register 45 according to the address.
2. The status data of the scanner unit 110 written to either the command register 453 or the status bus receiver 454 or the basic status receiver 455 is transferred to the path transceiver 4.
58. The data is read into the CPU 401 via the CPU bus. In this way, the scanner unit 11
0 and reads the status of the scanner unit 110 to the CPU 401. Also,
Among the interface signals between this scanner interface 409 and the scanner unit 110, data (IDAT) is input/output via the path transceiver 457.
has a bus structure, and the status signal @ (
It has three states depending on the states of two signals: I5DAT) and a command signal (ICMO). That is, the status data of scanner unit 110, scanner unit 1
It has three states: command data to the scanner unit 10 and image data read by the scanner unit 110. Also, the timing of sending and receiving this various data is determined by the scanner unit 11.
It is controlled by a busy signal (ISBSY) outputted from 0 and a write signal @ (IWR) outputted from the timing generation section 451. In addition, the interrupt F/F 459 sends an interrupt signal (INTO) to the CPU 401.
IS is something that will help you.

Said bus 1-7? The image data input from the scanner unit 110 via the receiver 457 is output to the image processing section 456, where the image is enlarged.

The image is subjected to reduction (processing related to the main scanning direction) and trimming (image extraction), and then sent to the image bus.

Details of this image processing section 456 will be explained with reference to FIG. 29. This image processing section 456 has two line memories 46
0.461, and these two line memories 460.4
The image is enlarged or reduced by alternately reading and writing to and from 61. Note that since it is necessary to read and write image data as serial data into this line memory 460 and 461, the image data that is input in parallel is converted into serial data by a parallel-serial converter (hereinafter referred to as a P-S converter) 462. The image data read out from the line memories 460 and 461 is serial-parallel converted (hereinafter referred to as an S-P converter) 46
3 to output to the converter image bus in parallel.

Then, an address signal for reading/writing to/from the line memories 460, 461, a write/read timing signal, and a P-3 converter 462. Various blocks are provided that output timing signals for setting the conversion timing of the S-P converter 463. Write timing generation circuit 4
64. The read timing generation circuit 465 outputs two types of clocks: 8 clocks corresponding to 8-bit image data and a delayed clock thereof each time a strobe (STB) signal is input. This clock is then transmitted to the P-8 converter 462. used as the timing signal of the S-P converter 463 and as the write/read timing signal via the timing selector 467,
Furthermore, it is used for generating address signals.

As a block that generates the address signal, there is a line memory address counter parameter register 468. Decimal counter section 469. Decimal address counter integer part 47
0. An integer address counter 471 and two address selectors 472, 473 are provided. The line memory address counter parameter register 468 is
An enlargement or reduction magnification to be counted is set for the decimal counter section 469, and initial values are set for the decimal address counter integer section 470 and the integer address counter 471. Decimal counter section 469
adds the enlargement and reduction magnifications for each clock and outputs the carry of the sum of the decimal parts. For example, in the case of 0.7x, a carry is output until the third clock, but a carry is not output at the fourth clock, <0.7X3
=2.1.0.7X4=2.8, so there is no decimal carry). The decimal address counter integer section 470 is configured to advance the count only when a carry occurs in the decimal address counter section 469.

On the other hand, the integer address counter 471 is configured to advance the count every clock.

When data is reduced, the output of the decimal address counter integer part 470 is used as an address to store the line memory 472.
Alternatively, by writing data into the memory 473, data is written with one missing data every few, and the read address is determined by the integer address counter 471 to generate reduced data. On the other hand, when enlarging data, the integer address counter 471 writes the data as it is to the line memory 471 or 473, and the reading address is determined by the decimal address counter integer section 470, so that the same data is successively read out and enlarged by lIgA in several pieces. It is designed to create data. For this purpose, the decimal address counter integer part 470. Address selectors 472 and 473 are provided which respectively input the outputs of the integer 7 address counter 471 and select and output them to the line memories 460.degree. 461. Note that the selection of addresses with this address selector 472 and 473 is expanded.

This is done based on the output of the reduction timing controller 474.

Here, the data reduction and expansion operations are shown in Figure 30 (A) and (
This will be explained with reference to the timing chart shown in B). FIG. 30 (A> is a timing chart showing the data writing operation to the line memories 460 and 461;
FIG. (8) is a timing chart showing the data read operation from the line memories 460 and 461. Data D
08 to 001 are converted into serial data by the wear-in timing generation section 464 and the output clock CP. Further, the decimal counter section 469 outputs a carry from the rising edge of the clock CP, and has a reduction magnification such that no carry is output at the seventh clock, for example.

Therefore, the decimal address counter integer section 470 sequentially updates the write address only while a carry is output from the decimal counter section 469, but when the carry is not output, it does not update the write address and the data DO2 ,001 common address ADS
+6 will be specified. As a result, the same address data D02 and DOl are continuously read and written onto the line memory, and as a result, the data DO2 is erased, resulting in data loss. Since this data is read out using the address of the integer address counter 471 that is updated in response to the clock CP as shown in FIG. will be generated.

When expanding data, the integer address counter 47 is updated in response to the clock CP as shown in FIG. 30(A).
The line memory 460 or 461 is programmed by the address 1. Therefore, data D08-001 will be written as is into the line memory. Then, data is read from this line memory based on the address of the decimal address counter integer section 470.

For example, as shown in FIG. 30(B), the decimal count section 4
When 69 is the sixth clock CP and the magnification is such that no carry is output, the decimal address counter integer part 470 does not update the address while this carry is not output, and the same address (ADS+5>f2 consecutive rotations) As a result, the same data is read out continuously and the data is enlarged.

In addition, the above enlargement and reduction operations will enlarge the image in the main operation direction.
In this case, the image in the sub-operation direction is enlarged or reduced by changing the scanning speed of the carriages 116 and 117, as described above. Also, when in the same-size mode, the same-size mode signal is input to the decimal count section 469, and the decimal address counter integer section 470 outputs the same address as the integer address counter 471, resulting in enlargement.

No reduction is performed.

Next, image extraction (
Trimming) I will explain the details. This trimming is performed by extracting data in the image extraction area by defining a data start position and a data end position. To set the starting position of data, connect the most significant bit of each of the loading and reading addresses to the chip select terminal of the memory element, and then store and read the data after that bit becomes 1. Set it to . The end position of the data is set at the address. Next, image extraction (trimming) is performed in this image data processing section 456.
I will explain about it. This trimming is performed by extracting data in the image extraction area by defining a data start position and a data end position. To set the starting position of data, connect the most significant bit of each write and read address to the chip select terminal of the memory element, and write after that bit becomes 1.
Set it so that it can be read. The end position of the data is set by setting the address in the address comparator 475, and by this address comparator 475, the gate 4 provided after the P-8 converter 462 is set.
76 or by controlling the data selector 478 provided before the S-P converter 463. Note that this address comparator 475 is connected to the integer address counter 47.
The operation is performed by inputting address 1.

Therefore, when the image reduction mode and cropping are performed together, the integer address counter 471 is used when reading data, so the data selector 478 that selects the read data is controlled by the address comparator 475. will be done. On the other hand, when image enlargement mode and cropping are performed together, the integer address counter 47 is used when writing data.
1 is used, the gate 476 that preselects the data to be written will be controlled by the address comparator 475.

The above trimming operation is performed in the main scanning direction, and trimming in the sub-scanning direction is performed as follows. That is, sub-scanning direction parameter register 480, address counter 481 . Address comparator 482 and gate 483
is provided.

This configuration corresponds to the above-mentioned trimming block in the main scanning direction. The most significant bit of the address counter 481 is connected to the gate 483 for the horizontal synchronization signal (MH8YN) and slope signal @ (MSTB), and if this bit does not become 1, both signals are transferred to the image memory. It is no longer output. This restricts the starting position of data in different scanning directions.

The end position of the data in the sub-scanning direction is determined by setting a value corresponding to the end position of the data in the address comparator 482. and address counter 482
When an address equal to or greater than the above value is counted by the address comparator 482, the data selector 478
control to force the data to zero. As a result, zero data is written into the page memory, and truncation in the sub-scanning direction is performed.

Next, regarding the LBP interface 410, a third
This will be explained with reference to FIG. This LBP interface 410 converts the control signal from the CPU 401 into LB.
In addition to informing the P300, the status of the LBP300 is also sent to the CPU.
410 and plays the role of transmitting the image data in the page memories 401 and 405 to the LBP 300. That is, the address signal is sent from the CPU bus to the address receiver 48.
5. Input via the address decoder 486 and read data on the CPU bus or LBP3 according to this address signal.
00 data is loaded into each register, and the CPU 401 reads the contents of each register, resulting in LBP30.
It sends commands to 0 and reads the status of LBP300. The registers include printer command register 490, printer status register 491. A command register 492 and a status register 493 are provided. Data on the CPU bus is also input via a data transceiver 487, and a print request signal (PREQ) from the LBP 300.

The print ready signal (PRDY) and the like are input via the receiver 489, and the print signal (PRT) and the like are output to the LBP 300 via the driver 495. In addition, this LBP interface 410 and LB
The data DAT8 to DAT1 exchanged with the P300 via the transceiver 488 have a bus structure, and the two are a status signal (DSTA) and a command signal (DCOM> output from the timing control circuit 499, which will be described later). It has three states depending on the signal state.

That is, the status signal of LBP300.

It has three states: a command signal to the LBP 300A, and an image signal to the LBP 300. The timing control circuit 499, which determines one of these three states, receives read/write signals from the bus interface 494, command information from the command register 492, synchronization signals from the transceiver 498 and the receiver 489, etc. Various signals are output to the LBP 300 based on. Further, the image signal from the image bus is sent to the data receiver 496. The data is transmitted to the LBP 300 via the data latch circuit 497 and the bus transceiver 488.

Next, various images produced by this example device! The lA collection operation will be explained.

<Image Composition Mode> First, the image composition mode in which a plurality of original images are composited and formed on one sheet of paper will be described with reference to FIG. 32. This mode is selected by pressing the composition mode selection key 50 on the first operation panel 6. When this key 50 is pressed, a plurality of documents are successively read by the scana unit 110 and sent to the photoelectric conversion unit 120.
is converted into a digital signal. When using ADFI, multiple originals are automatically fed one by one and read one by one. When not using ADFI, the original cover 2 is opened and closed for each original and the exposure glass 111 is read. A document is manually placed on top of the scanner, and each document is read one by one.

For example, the manuscripts Pt, P2, P3, shown in FIG.
The images of Pa are read one by one in the above manner.

The image read in this way is transferred onto the image bus via the scanner interface 409, and in the case of monochrome copying, it is stored in the image memory under address control of the first color page memory address controller 404, which is a write control means. It is written to the first color page memory 403.

At this time, the first color page memory address controller 40
4 sets the top addresses TPt to TPa on the image memory 403 as shown in FIG. 32 according to each original image, and stores each image at a different address on the image memory 403. Then, the contents of this image memory 403 are LBP
LBP unit 300 via interface 410
The first laser diode 314 is driven to emit light to form an electrostatic latent image of a composite image on the photoreceptor 301. Thereafter, based on the operation of the LBP unit 300 described above, four original images are formed on one sheet of paper T, as shown in FIG. Such a compositing mode allows a plurality of original images to be formed on one sheet of paper in a single image forming operation, reducing copying processing time and reducing paper consumption. still,
For those without ADFI, it is also possible to combine images by placing multiple originals on the exposure lath 111 at once, but if two or more originals cannot be placed at once, use A3 for example. This compositing mode is convenient when composing a plurality of originals of the same size. Also, A
When you select this composition mode using DFl, A
The compositing operation is performed for each document of a plurality of valves that are sequentially and continuously fed from the DFl, and the above operation can be performed continuously until the document presence detection switch 16 detects that there is no document, thereby reducing the burden on the operator. significantly reduced.

Further, when such a composition mode is selected, it is convenient to reduce the size of each of the plurality of original images and form them on a single sheet of paper. Therefore, auto magnification mode selection key 1
571 By using the magnification designation key 158 or the magnification selection key 159, the original image can be reduced and written in the image memory 403, and a composite image can be formed on a sheet of a predetermined size. Regarding image reduction, as described above, data in the main scanning direction is reduced by the image processing unit 456 of the scanner interface 409, and data in the sub-scanning direction is reduced by the carriage 1.
16. Reduce the size by varying the scan speed of 117.

Image compositing mode (10) Variable number of originals to be combined> Although the image compositing mode described above can be performed by fixing the number of originals to be combined in the apparatus, it is more practical to make the number of originals to be combined variable. In this embodiment, the composition mode selection key 50
The first numeric keypad 5 serves as a means for inputting the number of original sheets when pressed.
By operating 6, the number of originals to be combined can be set as desired. Then, the plurality of originals specified by the first numeric keypad 56 are sequentially read and formed into one sheet of paper. Note that the first color page memory address controller 404, which is a write control means, sets the top address TP according to the specified number of originals, and stores the plurality of original images in the image memory 4.
This means that writing will be specified to a different address of 03.

<Image Synthesis Mode: Variable Number of Generated Originals and Number of Output Papers> It would be more practical if the image forming operation of compositing a predetermined number of originals onto one sheet of paper could be performed continuously on a plurality of output sheets. In the device of this embodiment, the second operation panel 10
1, there is a second numeric keypad 15 which is a means for inputting the number of output sheets.
1 is provided to make the number of sheets of paper to form and output the same composite image variable. Additionally, the laser scanner unit 310
Based on the image data of a plurality of original documents written in the image memory 403, latent images are continuously formed on a specified number of sheets per rotation of the photoreceptor 301, and the upper cassette 3
A copying operation is continuously performed on sheets fed from the cassette 21 or the lower cassette 322. Therefore, each document only needs to be read once.

<Image extraction area specification and image formation position specification> For example, the third
Extract the effective surface &Dt of the original P shown in Figure 3 and print it on the output paper T.
The operation for forming the image D2 by reducing it at a predetermined position with a magnification M will be described. The extracted image D1 of the original P is -
Corner coordinate position X1. It is specified by Yt and the image size At and Bt. Further, the image forming position of the image D2 on the output paper T is specified by the coordinates X2 and Y2 of one corner of the image P2. Therefore, as an example for specifying the above coordinates and size, for example, the information shown in FIG. 34 is displayed on the LCD 5,
It is possible to request input of numerical values corresponding to each piece of information using the cursor 5B. That is, the image extraction mode selection key 51 and the output position specification mode selection key 5 on the first operation panel 6
2 is selected, the above display is performed on the LCD 5 under the control of the CPU 401. Then, by inputting information corresponding to the position of the cursor 5B via the first numeric keypad 56, the image extraction area and the image forming position can be specified. Once the image extraction area is designated as described above, the read image is subjected to the aforementioned reduction operation and trimming operation in the image data processing unit 456 of the scanner interface 409. When an image forming position is specified, the top address TP is set to a predetermined value by the image memory address controller 404, which is a write control means, and the address on the image memory 403 corresponding to the specified image forming position is set. Write. Thereafter, if an image forming operation is executed based on the contents of the image memory 403, an image D2 as shown in FIG.
can be formed on top.

<Image composition mode 10 Image formation position specification> In this example,
The above-mentioned designation of the image forming position can also be performed in the image composition mode.

That is, as shown in FIG. 35, the originals P1 are sequentially read.
It is possible to designate the image forming position for each of the images from P4 to rearrange the images and form them on the paper T. On this occasion,
After pressing the composition mode selection key 50, the first numeric keypad 56
Operate to set the number of originals to be combined. After that, when the image forming position designation mode selection key 52 is pressed, the third
The screen shown in FIG. 4 is displayed on the LCD 5. Note that when the image extraction mode selection key 51 is not selected, information regarding rREADJ is not displayed in FIG. 34.

Then, according to this display, the first numeric keypad 56 is operated to set the image forming position coordinates X2, Y for each document P1 to P4.
2 should be specified. Based on this designation, the page memory address controller 404, which is a write control means, determines the top address of each document image in the image memory 40 according to the coordinates X2°Y2. As a result,
As shown in Figure 35, the paper T is different from the original input order.
Each image can be combined and formed at the upper position.

Specifying extraction area division for a single document image If there are multiple images on a single document P as shown in FIG. mode. At this time, press the image extraction mode selection key 51 to display rREADJ shown in FIG. 34 on the CD5, and set the coordinates Xi, Y1, and size Al.

B1 is input via the first numeric keypad 56 to designate the extraction area of the image rAJ in the document P. Thereafter, for example, the image extraction mode selection key 51 is pressed again to sequentially designate the extraction areas of images rBJ and rcJ in the document P in the same manner. When division is specified in this way, the CPU 401 connects the scanner unit 110 to the scanner interface 409.
The drive control is performed via the drive control, and images of the same document P are read continuously for the number of divisions. Then, the page memory address controller 404, which is a write control means, trims the image according to the order specified for division for each reading operation, and writes the extracted image into the memory 403. Furthermore, the LBP unit 300 sequentially performs image forming operations on different sheets of paper based on the contents in the image memory 403, thereby producing an extracted image "A" as shown in FIG.

rBJ and rcJ are different papers Tt and T2, respectively.
.

It can be formed on T3. In addition to such division designation, it is also possible to designate an image forming position and/or select a reduction or enlargement mode.

Auto Magnification Mode> Next, a mode for automatically setting the copy magnification of an image based on the operation of the auto magnification mode selection key 157 provided on the second operation panel 101 will be described.

In order to automatically set the copy magnification, it is necessary to detect at least the size of the original image and the size of the output paper in advance. When using ADF1, the vertical and horizontal sizes of the document are detected by the document width detection switch 1°4 and the document switch 21. Furthermore, when the image extraction mode is selected, the size A1°81 of the image extraction area shown in FIG. 33 can be detected manually. On the other hand, the size of the output paper is determined by the upper cassette size detection switch 325 or the lower cassette size detection switch 3, which detects the paper size by determining the types of the upper and lower cassettes 321 and 322.
28. The CPU 401 can input this size information via the CPU bus and detect the size of the original and output paper in advance. Then, when the auto magnification mode selection key 157 is pressed, the CPU 401 can calculate the copy magnification from the size information. The CPU 401 then scans the scanner unit 11 via the scanner interface 409.
The scanning speed of the carriages 116 and 117 at 0 is controlled based on the copying magnification to perform an enlargement or reduction operation in the sub-scanning direction.

Further, information on the copying magnification is sent to the image data processing unit 456 of the scanner interface 409 to perform enlargement and reduction operations in the main scanning direction. In this way, an image forming operation based on the auto magnification mode is performed. Further, such auto magnification mode can also be performed in conjunction with the above-mentioned combination mode. In the composite mode, the copy magnification is automatically set for each document to be composited.

<Composition mode + original contour erasing mode> When forming multiple original images on a single sheet of paper, the outlines of each original may be formed on the paper, resulting in an unattractive copy. . In the device of this embodiment, after pressing the image deletion mode selection key 53, the first numeric keypad 56
By specifying the contour area, the image data of this area can be forced to zero on the image memory 403. For example, as shown in FIG. 37, the outline areas of the document ■, ■
.

When erasing (1), (2), the CPU 401. J:')
XN1. XN2. YNl, YN2 and top address TP
z ~ TPJ, each register 423, 430.432
Set sequentially.

When all data in area (2) is to be cleared, TPz is written to each of the registers 423, 430, and 432.

XN1. The operation is started by setting YNl and setting the all clear command assigned to a specific bit of the command boat 421 to "1". The page memory address controller 404 first outputs the address of TPl to the image bus via the address transceiver 427, and at the same time sets the signal on the image bus that disables the data bus to "1", and then Outputs a write signal. Next, a write signal is output while sequentially updating the address from the address transceiver 427, and when this operation is repeated XN1 times, a carry is output from the XN counter 431. Then, only one YN counter 433 is updated and the address is set to the value of TP1+xw. The above operation is performed until the YN counter 433 counts YN once, and when this value is counted, a carry is output from the YN counter 433, and the all clear operation for the area (2) is completed. Similarly for areas ■～■, TP2～T
P4. XN1. XN2. YNI.

This can be done by setting YN2. Roughly speaking, in the case of composite mode, the outline area of each document is set to the top address and
, YN, the outline of each document can be erased on the image memory 403.

<Contour $2 Inclusion Mode> After erasing the outlines of the originals to be combined as described above, the outlines of each original are newly created in the image memory 403.
can be incorporated. At this time, the image deletion mode selection key 53. After specifying the contour area to be erased with the first key 56, the mode selection key 54 is pressed to select a frame as the contour writing mode selection means. Then, following the above-mentioned contour area erasing operation, a new contour line is added to this area.
Command boat 421 from 01. TP, XN, and YN are set in each register via
The data address and data length where the data to be written are stored are programmed into the DMA controller 411 shown in FIG. 6, and the DMA operation is enabled. D
The MA controller 411 uses the designated image memory 403
The upper address is automatically accessed and "1" is written in the corresponding address on the outline to frame it.

<Begging mode> The above-mentioned DMA controller 411 can read and write various data onto the image memory, and is not limited to only the outline of the document. For example, page numbers may be attached to the output paper. The number as the page code is stored, for example, in a lower memory of the program memory 402, and the DMA controller 411 can read this page code information from the program memory 402 and write it into the image memory 403. There are two types of page code writing modes.

One is to press the page mode selection key 55 and the "input order" selection key 55A on the first operation panel 6 to form images of each document in the composite mode as shown in FIG. 38. This is a mode in which a page code is attached to a position corresponding to an area. The other one is the paged mode selection key 55.
By pressing and "output order" selection key 55B,
As shown in FIG. 39, this is a mode in which page numbers are attached to the sheets in the order in which they are output.

In the former "input order" mode, the CPU 401 can detect each top address TP1 to TPa and the sizes XN and YN of the page code forming area shown in FIG. 38 from the output paper size and the number of combined original sheets. Each data is stored in each register 423 of the page memory address controller 404,
430 and 432 via the command boat 421, and thereafter each page code can be written on the image memory 403 by the DMA controller 411.

Even in the latter "output order" mode, the top address TP and size X of the page code formation area are determined from the output paper size.
N, YN can be detected, these data can be set in each register 423, 430, 432 via the command boat 421, and page codes can be assigned in the output order by the operation of the DMA controller 411.

Note that the above-mentioned "input order" mode and "output order" mode can be used together, and furthermore, the image forming position designation mode, trimming, enlargement, and reduction mode can also be used together.

Note that the present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the paper of the present invention.

[Effect of the Invention 1] As explained above, according to the present invention, the present invention has a function of forming and outputting images of a plurality of originals on one sheet of paper, and
It is possible to provide a digital image forming apparatus that can erase portions corresponding to the contours of each document and add new boundary lines.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of an apparatus according to an embodiment of the present invention, FIG. 2 is a main control block diagram of the apparatus according to the embodiment, FIG. 3 is a schematic cross-sectional view of the apparatus according to the embodiment, and FIG. 4 (A). (B) is a partially cutaway plan view and a schematic sectional view of the document mounting table, FIG. 5 is a control block diagram of the scanner unit, and FIG. 6 is a schematic explanatory diagram illustrating the main timing signals for document reading by the scanner unit. , FIG. 7 is a schematic sectional view of a laser scanner unit, FIGS. 8(A) and 8(B) are schematic explanatory views showing an example of the arrangement of the exposure portion of a photoreceptor, and FIG. 9(A). (B) and (C) are schematic explanatory diagrams explaining the drawbacks when two-color printing is performed using the contact development method, and FIG. 10 is a schematic diagram explaining the contamination of toner when two-color printing is performed using the contact development method. figure,
FIG. 11 is a schematic cross-sectional view showing an example of a developing device using a non-contact developing method, FIGS. )～(D)
is a schematic explanatory diagram for explaining the principle of solving the occurrence of color mixture, FIG. 14 is a schematic perspective view of a laser scanner unit,
Fig. 15 (A) is an explanatory diagram showing the deviation of the scanning start point of the laser beam, Fig. 15 (B) is an explanatory diagram showing the mismatch in the scanning length of the laser beam, and Fig. 16 is an explanatory diagram showing the mismatch of the scanning start point of the laser beam.
A block diagram showing the interface, FIG. 17 is the LB
A schematic explanatory diagram showing signals between the P unit and the LBP interface, Fig. 18 is a block diagram showing an example of the print control section of the LBP unit, and Fig. 19 shows laser beam scanning in the print control section shown in Fig. 18. 20 is a timing chart illustrating the operation of correcting the start point deviation, FIG. 20 is a timing chart illustrating the horizontal synchronization signal forming operation in the sub-scanning direction in the print control section, and FIG. 21 is another example of the print control section. 22 is a detailed block diagram of the quaternary counter and selector of the print control unit shown in FIG. 21, FIG. 23 is a timing chart of the operation for correcting the mismatch in scanning length of the laser beam, and FIG. 24 is the first. A schematic explanatory diagram of the second operation panel, FIG. 25 is a block diagram of the page memory address controller, FIG. 26 is a block diagram of the DMA controller, FIG. 27 is a block diagram of the image memory, and FIG. 28 is a block diagram of the scanner interface. 29 is a detailed block diagram of the image data processing section shown in FIG. 28, and FIGS. 30(A) and 30(B) respectively explain enlargement and reduction of data in the image data processing section. Fig. 30 (A) is a timing chart when writing to the line memory, Fig. 30 (B) is a timing chart when reading from the line memory, and Fig. 31 is a timing chart when writing to the line memory.
A block diagram of the interface, FIG. 32 is a schematic explanatory diagram explaining the image composition mode, FIG. 33 is a schematic explanatory diagram showing various information for specifying image extraction and image forming position,
FIG. 34 is a schematic explanatory diagram showing an example of a display requesting information for inputting the information shown in FIG. A schematic explanatory diagram illustrating the division designation mode of the image extraction area, FIG. 37 is a schematic explanatory diagram illustrating the mode for erasing the outline of the document, and FIG. 38 is a schematic explanatory diagram illustrating the mode for erasing the outline of the document. FIG. FIG. 39 is a schematic explanatory diagram illustrating a mode in which page numbers are attached to output sheets in the order in which they are output. DESCRIPTION OF SYMBOLS 1... Automatic document feeder, 50... Composite mode selection means, 53.56... Contour erasure mode selection means, 54...
Contour writing mode selection means, 110.120... Reading device, 300... Image forming means, 403.405... Image memory, 404.406... Writing control means. Agent Patent Attorney Masayoshi Misawa Figure 6 Figure 8 (A) Figure 12 CB) CD) 1 (A) CB) (D) Figure 36 Tl 12
13Figure 37Figure 38N

Claims (3)

[Claims] (1) A reading device that digitally reads an image on a document, an image memory for storing the read image data, and the image data read by the reading device is stored in the image memory directly or after editing. In a digital image forming apparatus having a writing control means for writing, and an image forming means for forming a document image on a sheet based on image data stored in an image memory, a plurality of document images are stored at different addresses in the image memory. a composition mode selection means for selecting an image forming operation for compositing and forming a plurality of original images on one sheet of paper based on the contents of the image memory; contour erasing mode selecting means for selecting a mode for erasing a portion to be erased on the image memory; and contour writing mode selecting means for selecting a mode for writing a new outline on the image memory after the erasing operation. A digital image forming device characterized by: (2) The digital image forming apparatus according to claim 1, further comprising an automatic paper feeding device that automatically feeds original documents one by one to a reading device. (3) The digital image forming apparatus according to claim 1 or 2, wherein the image memory stores image data corresponding to an image reduced in size from the actual size of the original image.