JP2001331011A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten image forming time at the time of forming the image of an original whose size is equal to or under the half of maximum readable size on plural sheets of material to be recorded in one-to-one. SOLUTION: When two originals 1 and 2 are fed to the reading position of an original platen glass, the original 1 is scanned from an HP for the purpose of acquiring a magenta image, and image processing is performed to the read image data of the original 1, and then the image of the magenta image data of the original 1 is formed on a photoreceptor drum by a printer part. During such processing, the original 2 is continuously scanned for the purpose of acquiring the magenta image after scanning the original 1, and the magenta image data of the original 2 is stored in a storage medium by the time the image of the magenta image data of the original 1 is formed. After forming the image of the original 1, the magenta image data of the original 2 is read out, and the image of the magenta image data of the original 2 is formed. Processing for cyan, yellow and black images is performed in the same procedure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image forming apparatus such as a digital copying machine system.

[0002]

2. Description of the Related Art Conventionally, a color image forming apparatus such as a digital color copier electrically processes an image signal read by a reading unit to obtain magenta (M), cyan (C), yellow (Y), and black. It is decomposed into each component of (BK) and sent to the printer unit. For each reading (document scanning),
Since one component of M, C, Y, and BK is sent to the printer unit, one printout is completed by scanning the document four times in total.

[0003] Each of the original scans forms an electrostatic latent image of M, C, Y, and BK on the photosensitive drum, and is developed with toner corresponding to the electrostatic latent image. Then, in order to transfer four toner images of M, C, Y, and BK, which are developed on the photosensitive drum, onto the copy paper, the paper is wound around a transfer drum, and the toner is transferred four times while rotating the drum four times. Transfer the image. That is, one rotation of the transfer drum can print out one sheet.

The transfer drum is large enough to wind the maximum size (for example, A3) of copy paper. If the size of the paper is half (for example, A4), two sheets can be wound. Therefore, when copying a plurality of originals using the paper of that size, wind two sheets of the size on the transfer drum. I was That is, two copies can be made with four rotations of the transfer drum, and productivity has been improved. As a result, for example, the copy paper becomes A4 or B5.
When copying a plurality of originals of a single size, two copies can be made by rotating the transfer drum four times by winding two sheets of copy paper around the transfer drum.

[0005]

To take advantage of this advantage,
In order to increase the copy speed when copying in to1, in order to copy a plurality of originals having a half of the maximum copy size, a document feeder (DF) is used to copy two originals to the original platen at a time. There is a method in which an original is placed, two originals are scanned by one scan, and an image from each original is formed on two sheets attached to the transfer drum. In order to form a latent image of a second scanned image of a document at a predetermined second position on the photosensitive drum, the timing of output of the latent image is adjusted in consideration of time such as a sheet interval. There was a problem that had to be adjusted.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art.
1-to-1 copy of the original image smaller than 1/2 the maximum readable size
1 reduces the image forming time when forming on a plurality of recording materials, or when forming an image of a bound two-page spread original one page at a time on a recording material (page continuous shooting) To provide an image forming apparatus.

[0007]

In order to achieve the above object, the present invention provides a document placing means on which a document is placed, and a method for scanning a document placed on the document placing means, thereby forming an image on the document. Image reading means for reading, an image carrier for carrying a latent image based on image information read by the image reading means,
Control means for controlling an image forming process, the image forming apparatus forming an image of a document on a recording medium, wherein the image carrier is an image of a document to be formed on a plurality of recording media In an image forming apparatus capable of carrying a latent image of information at a predetermined position, a plurality of originals to be recorded on a plurality of recording media, each having a size per one of the image reading means. When a document having a size equal to or less than の of the maximum size of the document that can be read is placed side by side on the document placing means, the image of the document placed on the second and subsequent sheets in the document scanning direction is A storage unit for storing image information obtained by reading, the control unit corresponding to the second and subsequent recording materials based on the image information of the second and subsequent documents stored in the storage unit; Make it into each predetermined position It characterized in that for supporting a latent image of the image information Les document.

The image processing apparatus further includes a discriminating means for discriminating which of the plurality of document image information read by the image reading means is image information of the second and subsequent documents. May be stored in accordance with the result of the determination.

When a plurality of originals are arranged side by side on the original placing means, each original is placed at a predetermined position, and the image reading means detects a scanning position. Means may be provided, and the determination means may perform the determination based on the scanning position detected by the scanning position detection means.

It is preferable that the apparatus further comprises a document conveying means for conveying a plurality of documents to a predetermined position of the document placing means.

Preferably, the image forming apparatus is capable of forming a color image.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, based on a preferred embodiment,
The present invention will be described.

FIG. 1 is an external view of an apparatus according to a first embodiment of the present invention.

In FIG. 1, reference numeral 201 denotes an image scanner unit (image reading means) which reads a document and performs digital signal processing. Reference numeral 200 denotes a printer unit, which prints out an image corresponding to the document image read by the image scanner 201 on paper (recording material) in full color.

In the image scanner unit 201, 20
2 is a document feeder (document conveying means) including a document pressure plate (D
F), the original 204 on the original platen glass (original placing means) 203 is pressed onto the original glass 203. A document 204 on a platen glass 203 is irradiated with light from a halogen lamp 205. The reflected light from the original is reflected on mirrors 206 and 2
07, an image is formed on a three-line sensor (hereinafter referred to as a CCD) 210 by a lens 208. The lens 208 is provided with a far-infrared cut filter 231.

The CCD 210 separates the light information from the original into colors to obtain full-color information red (R), green (G),
The blue (B) component is read and sent to the signal processing unit 209. Note that 205 and 206 are speeds v, and 207 is 1/2.
The entire surface of the document is scanned by mechanically moving in a direction v (hereinafter, a sub-scanning direction) with respect to an electrical scanning direction (hereinafter, a main scanning direction) of the line sensor at v.

Reference numeral 211 denotes a standard white plate, and R, G, B sensors 210-1 to 210-3 generate correction data of read data. As shown in FIG. 2, this standard white plate shows almost uniform reflection characteristics from visible light to infrared light.
Visible, it has a white color. The output data of the visible sensors of the R, G, B sensors 210-1 to 210-3 is corrected using this standard white plate. Reference numeral 230 denotes an optical sensor which produces an image leading edge signal VTOP together with the flag plate 229.

In the signal processing unit 209, the read R,
The G and B signals are electrically processed, decomposed into magenta (M), cyan (C), yellow (Y), and black (BK) components, and sent to the printer unit 200. In addition, for one document scan (scan) in the image scanner unit 201, one component of M, C, Y, and BK is assigned to the printer 20.
0, and one printout is completed by scanning the document a total of four times.

In the printer unit 200, the M, C, Y, and BK image signals sent from the image scanner unit 201 are sent to a laser driver 212. The laser driver 212 modulates and drives the semiconductor laser 213 according to the M, C, Y, and BK image signals. The laser beam scans on the photosensitive drum 217 via the polygon mirror 214, the f-θ lens 215, and the mirror 216. Reference numerals 219 to 222 denote developing devices, which are a magenta developing device 219, a cyan developing device 220,
The developing device includes a yellow developing device 221 and a black developing device 222, and four developing devices alternately contact the photosensitive drum 217.
The M, C, Y, and BK electrostatic latent images formed on the photosensitive drum 217 are developed with corresponding toner. Reference numeral 223 denotes a transfer drum (image carrier) which winds the paper fed from the paper cassette 224 or 225 around the transfer drum 223.
The toner image developed on the photosensitive drum 217 is transferred to a sheet. After the four colors of M, C, Y, and BK are sequentially transferred in this manner, the sheet passes through the fixing unit 226 and is discharged.

FIG. 3 shows the document feeder (D) shown in FIG.
F) is a diagram for explaining the document feeding operation of 202, (a)
(B) shows a copy completion state of the first sheet, (c) shows a document conveyance state, and (d) shows a document discharge state. When a document on the document tray is fed as shown in FIG. 3 (a), the document feeder (DF) 202 sets the document on the platen glass. After the original is detected and the original is copied (b), the original on the original glass is transported (c) and discharged to the original tray (d).

Next, the image scanner 201 will be described in detail.

A halogen lamp 205 serving as a document illumination light source
Is used for reading visible information, and has both the illumination wavelength components necessary for reading the information.

FIG. 4A shows a CCD 21 using the present embodiment.
0 is shown. Here, 210-1, 210-2, 21
Reference numerals 0 to 3 denote light receiving element arrays for reading R, G, and B wavelength components in order. As shown in FIG.
The R, G, and B sensors up to 210-3 are in the main scanning direction,
It has an opening of 10 μm in the sub-scanning direction. The three light receiving element arrays having different optical characteristics are monolithically formed on the same silicon chip so that the R, G, and B sensors are arranged in parallel with each other to read the same line of the document. I have. By using a CCD having such a configuration, the optical form of a lens and the like in each color separation reading is made common, thereby making it possible to simplify the optical tonality of R, G, and B color sheets.

FIG. 4C is a sectional view taken along the dotted line in FIG.
Shown in Photosensors 210-1 and 210- for reading R, G and B visible information on a silicon substrate 210-4
2,210-3 are arranged. R photo sensor 2
An R filter 210-6 that transmits a red wavelength component of visible light is disposed on 10-1. Similarly, a G filter 210-7 is provided on the G photosensor 210-2,
B filter 210-8 on the photo sensor 210-3
Is arranged.

Referring to FIG. 5, R, G, B of CCD 210
The spectral characteristics of the filter of the line sensor will be described. The characteristic indicated by R is the output characteristic of the sensor by the R filter 210-7, and has sensitivity to light in the red wavelength range and the infrared wavelength range. The characteristic indicated by G is the output characteristic of the sensor by the G filter 210-8, and has sensitivity to light in the green wavelength range and the infrared wavelength range. The characteristic indicated by B is the B filter 2
The output characteristics of the sensor according to 10-9, which have sensitivity to light in the blue wavelength range and the infrared wavelength range.

As can be seen from this figure, the R, G, B filters 210-6 to 210-8 have sensitivity to infrared light of 700 nm or more. Therefore, a filter 210-9 for cutting infrared light is provided corresponding to the R, G, and B photosensors. This infrared cut filter 2
10-9 is composed of a laminated deposited film of SiO2 and TiO2 and has the characteristics shown in FIG. 210-5 is a flattening layer made of a transparent organic film.

FIG. 4B is an enlarged view of the light receiving element.
The R, G, and B sensors each have 10 pixels per pixel in the main scanning direction.
It has a length of μm. Each of the R, G, and B sensors has 5000 pixels in the main scanning direction so that the short direction (297 mm) of an A3 document can be read at a resolution of 400 dpi.

The distance between the lines of the R, G, and B sensors is 80 μm, and the R, G, and B lines are separated by 8 lines for a sub-scanning resolution of 400 dpi.

Next, the flow of an image signal will be described.

FIG. 7 is a block diagram showing a flow of an image signal in the image scanner section 201. The image signals R1, G1, and B1 output from the CCD 210 are input to an analog signal processing unit 3001 and subjected to gain adjustment and offset adjustment, and then A / D converters 3002 to 3004 for each of the R2, G2, and B2 color signals. It is converted into an 8-bit digital image signal. After that, the shading correction unit 30
05 to 3007, and a known shading correction using a read signal of the standard white plate 211 is performed for each of the R3, G3, and B3 color signals.

Reference numeral 3015 denotes a clock generation unit which generates a clock for each pixel. The main scanning address counter 3016 is an up counter, counts clocks,
Generate the pixel address output for the line. Reference numeral 3017 denotes a decoder which decodes a main scanning address from the main scanning address counter 3016, and drives a line-by-line CCD drive signal such as a shift pulse or a reset pulse, and a VE indicating an effective area in a one-line read signal from the CCD. A signal and a line synchronization signal HSYNC are generated. The main scanning address counter 3016 is cleared by the HSYNC signal,
The counting of the main scanning address of the next line is started.

As shown in FIG. 4B, since the light receiving sections 210-1, 210-2, and 210-3 of the CCD 210 are arranged at a predetermined distance, the R, G, and B sensors are placed on the original. Different line positions of the original on the table will be read.
The line delay elements 3010, 3011 and 3012 correct a spatial shift in the sub-scanning direction. In order to correct this, the original information is read in the sub-scanning direction with respect to the B4 signal. Specifically, the R4 and G4 signals are delayed by 32 lines, 16 lines and 8 lines in the sub-scanning direction, and Adjust to the signal.

Reference numerals 3010, 3011 and 3012 denote light quantity / density conversion units constituted by a look-up table ROM for converting the luminance signals of R5, G5 and B4 into density signals of C1, M1 and Y1. Reference numeral 3013 denotes a well-known masking and UCR circuit, which will not be described in detail. However, a black signal (B) is generated based on the input three primary color signals C1, M1, and Y1.
K) is extracted, and a calculation for correcting the color turbidity of the recording color material in the printer 212 is performed.
The signals 2, 2, and BK2 are sequentially output at a predetermined bit length, for example, 8 bits, for each reading operation.

Reference numeral 3014 denotes a CPU which controls a motor driver 3018 for driving a motor 129 of the original reading optical system and turns on / off the original illumination lamp 205.
It generates sequence control such as control of the lamp driver 3019 and generates a pixel section signal VSYNC in the sub-scanning direction.

3500 is a control device (control means,
CPU 3501, RAM 3502, RO
M3503, which controls switching between writing and reading of the memory 3504 (storage means) in accordance with the number of originals read, and controls transmission of each color image data to the printer unit 200 based on a control command stored in the ROM 3503. By controlling, the color image forming process is accelerated as described later.

FIG. 8 shows the configuration of the amplifier 800 of the CCD 210. CPU 3014 is a 7-bit D / A converter 80
By controlling 1 to 803, the output voltage gain of the CCD is determined.

FIG. 9 shows the timing of each control signal. V
The SYNC signal is an image valid section signal in the sub-scanning direction, and performs image reading (scanning) in a logical "1" section to sequentially perform (C), (M), (Y), and (BK).
Is formed. The VE signal is an image effective section signal in the main scanning direction, takes the timing of the main scanning start position in the section of logic "1", and is mainly used for line measurement control of line delay. The CLOCK signal is a pixel synchronization signal, and transfers image data at the rising timing of “0” → “1”.

Next, an embodiment of the present invention will be described with reference to the timing chart of FIG. 9, the arrangement positions of the respective sensors on the platen glass of FIG. 10, and the operation timing charts of the image scanner unit and the printer unit of FIG. I do. FIG.
At 0, HP is the home position of the halogen lamp 205 when reading a document. DP is a position sensor (scanning position detecting means), and a document feeder (DF) 202
Is mounted at a position corresponding to the leading end of the paper of the second original 2 placed on the platen glass 203, and is detected when the halogen lamp 205 passes through the sensor. This is to notify the image scanner unit 201 that the scanning of the position has started.

The document feeder (DF) 202 sends two of the documents placed on the document feeder (DF) 202 to the reading position of the document table glass 203 (S1). The halogen lamp 205 moves to the HP (S2), and the light sensor 232
, When the image is read while the halogen lamp is turned on until the reading start position of the original 1, the speed becomes the speed v when reading the image, and the magenta image is obtained by mechanically moving in the forward direction (direction away from the HP sensor) in the sub scanning direction The document is scanned for use (S3). At this time, the read image data of one A4 (or smaller size) is subjected to desired image processing in real time in the image scanner unit 201, and the image forming of the magenta image data of the original 1 is performed by the photosensitive drum on the printer unit. Do on top.

When the halogen lamp 205 finishes scanning the original 1 while the magenta image data of the original 1 is being formed by the printer unit, the halogen lamp 205 continuously scans the original 2 to obtain a magenta image. When the halogen lamp 205 moves to the DP at the leading edge of the document 2 and passes through the position sensor,
A paper leading edge signal of the original 2 is supplied to a storage medium (storage means) (not shown), and the storage medium corresponds to one A4 (or smaller size) of the original 2 scanned by the halogen lamp 205 using the paper leading edge signal as a trigger. Magenta image data is written. That is, the magenta image data of the document 2 is stored in the storage medium by the time the printer section completes the image formation of the magenta image data of the document 1. When the image formation of the magenta image data of the document 1 is completed, the printer section reads the magenta image data of the document 2 from the storage medium and forms an image of the magenta image data of the document 2 on the photosensitive drum. After scanning the document 2, the halogen lamp 205 moves to the HP position.

Next, with the same operation, the halogen lamp 205
Is turned on by the halogen lamp until the reading start position of the original 1.
The document is scanned for cyan image acquisition by mechanically moving in the direction (the direction away from the HP sensor) in the sub-scanning direction with the speed v at which the image is read while setting N (S3). At this time, the image data of one A4 (or smaller) image data is read by the image scanner unit 2.
In 01, desired image processing is performed in real time, and an image of the cyan image data of the document 1 is formed on the photosensitive drum by the printer unit.

When the halogen lamp 205 finishes scanning the original 1 while the printer unit is forming an image of the cyan image data of the original 1, the halogen lamp 205 continuously scans the original 2 to obtain a cyan image. When the halogen lamp 205 moves to the DP at the position of the leading edge of the document 2 and passes through the position sensor, the leading edge signal of the document 2 is supplied to a storage medium (not shown). 205
A4 (or smaller size) of original 2 scanned by
One sheet of cyan image data is written. When the image formation of the cyan image data of the original 1 is completed, the printer unit continuously reads the cyan image data of the original 2 from the storage medium and forms the image of the cyan image data of the original 2 on the photosensitive drum. After scanning the document 2, the halogen lamp 205 moves to the HP position.

The above operation is performed for each of the colors M, C, Y, and BK, thereby completing the image forming operation. Thereafter, the document feeder (DF) 202 discharges the document on the platen glass 203.

FIG. 12 shows the recording sheets 1 and 2 corresponding to the originals 1 and 2 wound on the transfer drum. The sheets 1 and 2 are spaced apart from each other as shown in the figure. The image formation of the document 1 is performed on the sheet 1, and the document formation of the document 2 is performed on the sheet 2. The transfer drum rotates in the direction of arrow C in the figure.

When the M, C, Y, and BK images have been formed on the sheets 1 and 2, the sheets are discharged through the fixing unit 226.

The above-described embodiment is also applied to a case where a bound two-page spread original is copied one page at a time (sequential page copying).

In this embodiment, a color copying machine is used as an example of the reading device. However, the present invention is also effective when the reading device makes a plurality of copies using a monochrome digital copying machine or the like, that is, performs a reading operation a plurality of times.

[0048]

According to the above-mentioned invention, when an image of a document having a size of 1/2 or less of the maximum readable size is formed on a plurality of recording materials in 1 to 1 or when a two-page spread book is bound. It is possible to reduce the image forming time when forming an image of a document one page at a time on a recording material (continuous page copying).

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a color copying machine.

FIG. 2 is a diagram illustrating a spectral reflectance of a white plate.

FIG. 3 is an operation principle of a document feeder (DF).

FIG. 4 is a diagram illustrating a structure of a three-line color sensor.

FIG. 5 is a spectral sensitivity characteristic diagram of the visible line sensor.

FIG. 6 shows characteristics of an infrared cut filter.

FIG. 7 is a block diagram illustrating a configuration of an image signal control unit.

FIG. 8 is a configuration diagram of a CCD amplifier.

FIG. 9 is a timing chart of an image signal.

FIG. 10 is a diagram showing an arrangement position of each sensor on a platen glass.

FIG. 11 is an operation timing chart of the image scanner unit and the printer unit.

FIG. 12 is a diagram illustrating a state of recording sheets 1 and 2 on a transfer drum.

[Explanation of symbols]

 200 Printer unit 201 Image scanner unit 202 Document feeder (DF) 203 Document table glass 204 Document 210 Line sensor 217 Photosensitive drum 219 Magenta developing device 220 Cyan developing device 221 Yellow developing device 222 Black developing device 223 Transfer drum 3500 Control device DP Position sensor

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2C087 AA09 AA15 AC08 BA07 BB10 BC07 CA02 CA05 2H027 DA23 DB09 ED04 ED06 ED16 EE01 EF09 FA19 FD08 ZA07 2H030 AD12 AD17 BB23 BB44 5C062 AA05 AB02 AB08 AB32 AC67 AF60 BA00 BB05 5C074 AA12 BB26 DD11 DD16 DD23 DD28 EE04 EE08 FF15 GG15 HH02

Claims (5)

[Claims] An image reading unit that scans an original placed on the original placing unit and reads an image of the original; and an image reading unit that reads the image of the original. An image forming apparatus that includes: an image carrier that carries a latent image based on image information; and a control unit that controls an image forming process, and an image forming apparatus that forms an image of a document on a recording medium. In an image forming apparatus capable of holding a latent image of image information of a document to be formed on a plurality of recording media at a predetermined position, a plurality of documents to be recorded on a plurality of recording media are used. In the case where a document having a size per sheet that is equal to or less than half the size of the maximum size document that can be read by the image reading means is placed side by side on the document placing means, Placed on the second and subsequent sheets Storage means for storing image information obtained by reading an image of a document which is present, wherein the control means controls the second and subsequent documents based on the image information of the second and subsequent documents stored in the storage means. An image forming apparatus, wherein a latent image of image information of each document is held at a predetermined position corresponding to a recording material. 2. The image processing apparatus according to claim 1, further comprising: a determination unit configured to determine which of the image information of the plurality of originals read by the image reading unit is image information of the second and subsequent originals. 2. The image forming apparatus according to claim 1, wherein the image information of the second and subsequent documents is stored in accordance with a result of the determination by the determination unit. 3. When a plurality of originals are placed side by side on said original placing means, each original is placed at a predetermined position, and said image reading means detects a scanning position. 3. The image forming apparatus according to claim 2, further comprising: a determination unit configured to perform the determination based on a scanning position detected by the scanning position detection unit. 4. The image forming apparatus according to claim 1, further comprising a document conveying unit that conveys a plurality of documents to a predetermined position of the document placing unit. 5. The image forming apparatus according to claim 1, wherein said image forming apparatus is capable of forming a color image.