JPH03178264A - Picture forming device - Google Patents

Abstract

PURPOSE:To copy an original with the optimum condition in response to the density state of the original by adjusting automatically the copy density of a 1st page depending on the density state of the 1st page and the copy density of a 2nd page depending on the density state of the 2nd page respectively. CONSTITUTION:A density discrimination storage means 14 is provided with a counter counting number of times of appearance for each density stage of each color, and the counter for density stage is counted up by one every time each point color and its density on an original are discriminated by a color discrimination means 12 and each color density distribution data is generated to be an EE data. In this case, the density is adjusted automatically for each color based on an EE data of the 1st page at the copy of the 1st page and the density is adjusted automatically for each color based on a 3EE data of the 2nd page at the copy of the 2nd page. Thus, the original of each page is copied under the condition optimum to the density state of the original.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to an image forming apparatus such as an electrophotographic color copying machine.

BACKGROUND ART AND PRIOR ART PROBLEM TO BE SOLVED BY THE INVENTION This type of copying machine is capable of copying in a page continuous copying mode in which two pages of an original are copied one page at a time onto two sheets of transfer paper, and in a preliminary scanning mode before the main scanning of the original. There is a known copying apparatus that can perform copying in an automatic density adjustment mode that determines the density state of the original and automatically adjusts the covey density.

In such a copying machine, when copying in automatic density adjustment mode in page quick copy mode, conventionally, two pages of the document are read simultaneously during preliminary scanning to determine the density state, and the density state of the two pages is determined based on the overall density state. The copies are made under the same conditions. Further, during preliminary scanning, only a portion of the first page of the original is read to determine the density state, and two pages are copied under the same conditions based on the density state of this part. In both cases, two pages are copied under the same conditions, so two pages are copied under the same conditions.
If there is an extreme difference in density between pages of the original, for example, the first page is a text original and the second page is a photo original, it may be difficult to obtain the optimal image for both pages. Can not.

An object of the present invention is to provide an image forming apparatus that solves the above problems.

Means for Solving the Problems An image forming apparatus according to the present invention includes a reading section that scans and reads a document, an image processing section that processes the output of the reading section and outputs image information, and an image forming apparatus that processes an image forming body using the image information. a recording section that forms an image in the image area and transfers it to transfer paper; an operation section for setting conditions;
It is equipped with a control unit that controls these, and is equipped with a page continuous copying mode that copies two pages of the original onto two sheets of transfer paper, one page at a time, and a preliminary scan before the main scan of the original to determine the density of the original. In image forming apparatuses that are now capable of copying in automatic density adjustment mode, which automatically adjusts the copy density by determining the and the density state of the second page are determined separately, the copy density of the first page is automatically adjusted according to the density state of the first page, and the copy density of the second page is automatically adjusted depending on the density state of the second page. It is characterized in that it is automatically adjusted.

The reading unit reads the document by separating it into at least two colors, the image processing unit outputs image information of at least two colors,
In the case of a color copying machine in which the recording section forms images of at least two colors, it is desirable to determine the density state of each color and adjust the copy density when copying in automatic density adjustment mode.

Effect When copying in automatic density adjustment mode in page continuous copying mode, the density status of the first page and the density status of the second page are determined separately by preliminary scanning, and the density status of the first page is determined depending on the density status of the first page. The copy density of the second page is automatically adjusted according to the density state of the second page. Therefore, even if there is an extreme difference in density between two pages of the original, each page of the original can be copied under optimal conditions according to the density of each original.

Embodiments Hereinafter, embodiments in which the present invention is applied to an electrophotographic color copying machine will be described with reference to the drawings.

FIG. 1 schematically shows the overall structure of a color copying machine, and FIG. 2 schematically shows the mechanical structure of the main parts.

A copying machine is roughly divided into a reading section (1>), an image processing section (2), a recording section (3), an operation section (4), and a control section (5).

The reading section (1) scans the original set on the document table (6), separates the image into three colors, and converts it into electrical signals. A scanning unit (8), color separation means such as a dichroic mirror (
9) and photoelectric conversion means (such as a CCD image sensor)
10), a reading unit (il) including a color discrimination means (
12), a color counter for three colors (13), a density discrimination storage means for three colors (14>, etc.).The color counter and density discrimination storage means are collectively referred to by symbols (13) and (14), and are distinguished from each other. If necessary, a red counter (13a), a blue counter (13b), a black counter (13c) and a red density discrimination storage means (14a) are provided, respectively.
, blue density discrimination storage means (14b), and black density discrimination storage means (14c). Color counter (13
) and the concentration discrimination storage means (14) are constituted by computer memory.

The image processing section (2) processes the output of the reading unit (11) and sends image information to the control section (5).

The recording section (3) includes a photosensitive drum (15) as an image forming body.
), and although not shown, an image area of a certain size (for example, A3 size) is provided on the surface of the drum (15).Also, around the drum (I5), a charger is provided. (1B), laser writing unit (17>, three developers (t8), transfer device (19), static eliminator (20),
The cleaning device (21), the second paper feed roller (registration roller) (23) of the paper feed device (22), and the separation belt (
24), a fixing device <25>, etc. are provided. The developing devices are also collectively referred to by the symbol (18), and when it is necessary to distinguish them, they are referred to as the first developing device (18a) and the second developing device (18), respectively.
b> will be referred to as the third developing device (18e). The first developing device (18a) is filled with red developer, and the second developing device (18b) is filled with red developer.
) is filled with blue developer, and the third developing device (18e) is filled with black developer.

The operation unit (4) is a part operated by an operator to set conditions for copying operations.

The control unit (5> is for controlling each part of the copying machine,
It is equipped with a microcomputer.

When the scanner (7) of the optical scanning unit (8) scans the document on the document table (6), each point on the document is separated into three colors of red, blue, and black by the color separation means (9). Photoelectric conversion means (
10) outputs an electrical signal proportional to the density of each color. The color discrimination means (i2) discriminates the color and density of each point on the document based on the output of the photoelectric conversion means (10), and uses a color counter (13) and a density discrimination memory as described below. Color data and density data (EE data) are created in the means (14). That is, the color discrimination means (1
0) determines whether the color of each point on the document is red, blue, black, or white from the output of the photoelectric conversion means (lO), and counts one color counter 03) for the corresponding color. rise. If it is determined that the color is white, none of the color counters will count up. Therefore, the color counter (i3)
The number of times each color appears is counted, and this becomes color data. The color determination means (0) also divides the density of each color into a plurality of stages, and determines which stage the color density of each point on the document falls into.The density determination storage means (14) includes: A counter is provided to count the number of appearances for each density level of each color, and each time the color discrimination means (10) discriminates the color and density of each point on the document, the corresponding color storage means (14) ) is incremented by one counter for the corresponding density level.As a result, the storage means (14) counts the number of times each density level of each color appears, and creates density distribution data for each color. EE data.Creation of such color data and EE data is performed only when data creation is permitted.
This is not performed when data creation is prohibited. Further, the color data of the color counter (13) and the EE data of the storage means (14) are cleared by a clear signal from the control section (5).

From the control unit (5), the γ correction data and MTF correction data of the image processing unit (2>, the value of the laser power of the writing unit (17), the charging potential of the charger (16), the developing device (1)
By controlling the developing bias voltage value etc. in 8>,
Copy density adjustment is performed.

The copying machine described above is capable of monochrome copying using any one of red, blue, or black, and multicolor copying using any two or three colors. Furthermore, single-shot copying, in which only one copy is made at a time, and continuous copying, in which a plurality of identical copies are made at a time, are possible.

In the case of monochrome copying, the original is scanned by a scanner (7), the image thereof is written on the image area of the drum (15) by a writing unit (17), and developed by one of the developers (18). And one scan,
Image formation is completed by writing and development, and this image is transferred to transfer paper fed by the second paper feeding roller (23) of the paper feeding device (22).

In the case of single-color single-shot copying, during one rotation of the drum (15), image formation is performed once by the scanner (7), writing unit (17), and one of the developing devices (18), and the second feed A sheet of transfer paper is supplied by a paper roller (23), and one image formed in the image area is transferred onto the sheet of transfer paper.

In the case of continuous monochrome copying, while the drum (15) is continuously rotating, image formation by the scanner (7), writing unit (17) and one of the developing devices (18), and the second
Paper is continuously fed by a paper feed roller (23), and images are transferred one by one onto a plurality of continuously fed transfer sheets.

In the case of multicolor copying, image formation is completed with two or three rotations of the drum (15) as follows.

That is, in the case of three-color copying, a red image is formed in the image area by the scanner (7), writing unit (17), and first developer (18a) in the first rotation of the drum (15), and in the second rotation. A blue image is superimposed on the image area by the scanner (7) writing unit (17) and second developer (18b), and in the third rotation, the scanner (
7>, writing unit (17) and third developer (1
8c), a black image is formed superimposed on the image area. In the case of two-color copying, since it is not necessary to form an image in any one color, image formation is completed with two rotations of the drum (15). Then, in the case of 3-color/copy, in the 3rd rotation, 2nd
In the case of color copying, a transfer paper is supplied by the second paper feed roller (23>) during the second rotation, and the multicolor image formed as described above is transferred onto this transfer paper.

In the case of continuous multicolor copying, if the size is larger than half of the maximum size (for example, A4 size), only one image is formed in the image area of the drum (15) and transferred to one sheet of transfer paper. When copying is performed in single sheet mode (normal mode) and the size is less than half of the maximum size, two identical images are formed in the image area of the drum (15) and one image is printed on each of the two sheets of transfer paper. Copying is performed in two-sheet mode.In the case of one-sheet mode copying, the scanner (15) rotates once while the drum (15) rotates once.
7), the document is scanned once and one image thereof is formed in the image area.

In the case of copying in the two-sheet mode, the document is scanned twice by the scanner (7) during one rotation of the drum (15), and two identical images are formed in the image area.

In addition, the above-mentioned copying machine uses a page continuous copying mode in which two pages of the original are copied one page at a time onto two sheets of transfer paper, and the color condition of the original is determined by preliminary scanning before the main scanning of the original. Copying in automatic color selection mode (ACS mode), which automatically selects the color to be used, and copying in automatic density adjustment mode (EE mode), which automatically adjusts the copy density by determining the density status of the original through preliminary scanning. It is now possible to do so. Note that when the ACS mode and the EE mode are performed simultaneously, the color state and the density state of the document can be determined in one preliminary scan. Further, automatic density: A adjustment is performed for each color.

The page snapshot mode is set by operating a predetermined button (switch) on the operation section (4). and,
For example, if you set two A4-size originals (total A3-size originals) on the document table (6) and use page quick copy mode to obtain two A4-size copies, select the A4-size transfer paper cassette. and press the copy button. In the case of monochrome copying, the first page of the original is scanned once and copied in a single color onto the first sheet of transfer paper, then the second page of the original is scanned and this is copied onto the second sheet. is copied onto transfer paper. In the case of multicolor copying, the first page of the original is scanned two or three times while the drum (15) makes two or three revolutions, and this is copied in multicolor onto the first sheet of transfer paper. Then, while the drum (i5) makes two or three revolutions, the second page of the original is scanned two or three times, and is copied in multiple colors onto a second sheet of transfer paper.

ACS mode and EE odd mode are set by scanning the auto button on the operation unit (4), but when the color mode button on the operation unit (4) is operated, the A
When the CS mode is canceled and the density button of the operation section (4) is operated, the EE odd mode is canceled.

When copying in ACS mode in page continuous copying mode, the color condition of the first page and the color condition of the second page of the document are determined separately by preliminary scanning, and the color condition of the first page is used depending on the color condition of the first page. The color is automatically selected, and the color used for the second page is automatically selected depending on the color state of the second page. Therefore, even if the two pages of the original have different color states, each page of the original can be copied using an image forming process that is optimal for the color state of each original. For example, if the first page is a red and blue original and the second page is a black original, the first page will be copied in two colors, red and blue, and the second page will be copied in two colors. , black monochrome copying is performed and unnecessary image forming processes are not performed.

When copying in EE odd mode in page continuous copying mode, the density state of the first page and the density state of the second page are determined separately by preliminary scanning, and the density state of the first page is determined depending on the density state of the first page.
The copy density of the page is automatically adjusted, and the copy density of the second page is automatically adjusted depending on the density state of the second page. Therefore, even if there is an extreme difference in density between two pages of the original, each page of the original can be copied under optimal conditions according to the density of each original.

Next, an example of the operation of the above-mentioned copying machine will be described with reference to the flowcharts of FIGS. 3 to 6 and the timing chart of FIG. 7.

The flowchart in Figure 3 is a routine for setting page continuous shooting mode, and the flowchart in Figure 4 is for ACS mode,
This is a routine for setting the EE odd mode and automatic paper selection mode (APS mode), and these are executed once at predetermined time intervals during the idling state from when the power is turned on until the copy button is pressed. be done.

In FIG. 3, first, in step 101, it is checked whether the page continuous copying button has been pressed. If it has been pressed, it is checked in step 102 whether or not the quick copying flag is set to 1. If the continuous shooting flag is set, the continuous shooting flag is reset to O in step 103 and the process is terminated; if the continuous shooting flag is not set, the quick shooting flag is set in step 104. , ends the process.

The quick-shot flag is a flag that is set when the page quick-shot mode is set and reset when the page quick-shot mode is canceled. Therefore, each time you press the page quick-shot button, the page quick-shot mode setting is and release is repeated.

In FIG. 4, first, in step 201, it is checked whether the auto button is pressed, and if it is, the automatic color selection flag (ACS flag) is set in step 202.
The automatic density adjustment flag (EE flag) is set in step 203, and the automatic paper selection flag (APS flag) is set in step 204.
are set respectively, and the process proceeds to step 205. If the auto button has not been pressed in step 201, the process directly advances to step 205.

In step 205, it is checked whether the color mode button is pressed, and if it is pressed, in step 206, the A
The CS flag is reset and the process proceeds to step 207. If the CS flag has not been pressed, the process directly proceeds to step 207.

In step 207, it is checked whether the density button is pressed. If it is pressed, the EE flag is reset in step 208 and the process proceeds to step 209. If it is not pressed, the process directly proceeds to step 209.

In step 209, it is checked whether the cassette selection button is pressed. If it is pressed, the APS flag is reset in step 210 and the process is terminated. If it is not pressed, the process is terminated.

The flowchart in FIG. 5 is a routine for preliminary scanning,
The flowchart in FIG. 6 is a routine for determining the color state and density state, and these routines are executed once at predetermined time intervals after the copy button is pressed. Further, the time chart in FIG. 7 shows the operation of the main parts during preliminary scanning.

In FIG. 5, first, in step 301, it is checked whether the forward flag is set.

The forward flag is a flag that is set when it is necessary to perform a preliminary scan, and if this is not set,
Since there is no need to perform preliminary scanning, the process ends without doing anything, and if it is set, the processes from step 302 onwards are performed.

Proceeding to step 302, a scanner forward signal is output,
Advance the scanner (7) and start preliminary scanning.

Next, in step 303, it is checked whether the scanner (A) is at the leading edge of the original (the leading edge of the first page of the original), and if it is at the leading edge, the data creation flag is set in step 304, and in step 305 The scanner position counter CNA is cleared, and each color counter (
13) is cleared, and in step 307 the EE data in each concentration discrimination storage means (14) is cleared, and the process proceeds to step 308. The pig creation flag is a flag for enabling data creation for the color counter (13) and storage means (L4). CNA is a counter for checking the position of the scanner (7), and is incremented by 1 at predetermined time intervals in a separate routine (not shown) when counting is permitted. If the scanner (7) is not located at the leading edge of the document in step 303, the process directly advances to step 308.

Proceeding to step 30B, it is checked whether the scanner (7) is at the rear edge of the document (the rear edge of the second page document), and if it is at the rear edge, the forward flag is reset at step 309, and at step 310 Set the return flag and end the process. When the return flag is set, a scanner return signal is output and the scanner (7) returns to its home position. Since the forward flag is reset in step 309, the process is thereafter completed in step 301 and no preliminary scanning is performed until the forward flag is set.

In FIG. 6, first, in step 401, it is checked whether the ACS flag is set, and if it is not set, then in step 402, it is checked whether the EE flag is set. If it is set, the process advances to step 403. That is, if both the ACS flag and the EE flag are not set, the process ends without doing anything, and only if at least one of them is set, the process from step 403 onwards is performed.

Proceeding to step 403, the check position constant CNTA is set to a predetermined value M. CNTA is a constant for determining the data check timing by the counter CNA, and a value M corresponding to the size of the transfer paper of the selected cassette is set to this constant.

Next, in step 404, it is checked whether the data creation flag is set, and if it is not set, the process ends; if it is set, the process proceeds to step 405.

In step 405, the counter CNA is placed in a counting enabled state. This causes another routine to start counting CNA.

Next, in step 406, it is determined whether the ASC flag is set, and if it is, step 406 determines whether the ASC flag is set.
Proceed to 07. In step 407, the color counter (13)
is placed in a color data creation permission state, and the process advances to step 408.

Thereby, the color discrimination means (12) starts creating color data. If the ACS flag is not set in step 406, the process directly advances to step 408.

In step 408, it is checked whether the EE flag is set, and if it is set, the process advances to step 409. In step 409, the concentration determination storage means (14)
is placed in an EE data creation permission state, and the process proceeds to step 410. As a result, the storage means (1) by the color discrimination means (12)
Creation of EE data in 4) begins. If the EE flag is not set in step 408, the process directly advances to step 410.

Proceeding to step 410, counter CNA is set to constant CNT.
It is checked whether they are equal to A, and if they are not equal, the process is terminated. If they are equal, the counter CNA is cleared in step 411 and the process proceeds to step 412.

Step 412 checks to see if the ACS flag is set, and if so, step 4 (3
Proceed to. In step 413, the contents of the color counter (13), that is, the color data, are read out and stored in a predetermined position.
is cleared and the process proceeds to step 415. Step 412
If the ACS flag is not set, the process directly advances to step 415.

In step 415, it is checked whether the EE flag is set, and if it is set, the process advances to step 41B. Step 4 (In step 6, density 1+1 separate storage means (1
The contents of step 4), that is, the EE data, are read out and stored in a predetermined location.Next, in step 417, the EE data in the storage means (14) is cleared, and the process proceeds to step 418. If the EE flag is not set in step 415, the process directly advances to step 418.

Proceeding to step 41&, it is checked whether the snapshot flag is set, and if it is set, step 41
In step 9, it is checked whether the first document flag is set. The first document flag is a flag that is set when the first page of the document is being scanned in the case of preliminary scanning for Pegazi continuous copying. In step 419, the first
If the original flag is set, that is, when the preliminary scanning of the first page of the original is completed, step 4
Proceed to step 20, reset the first document flag, and end the process. If it has not been set, proceed to step 421
Proceed to. If the snapshot flag is not set in step 418, the process directly advances to step 421.

Proceeding to step 421, the data creation flag is reset, step 422 sets the first document flag, and step 423 clears the counter CNA.

Next, step 424 checks to see if the ACS flag is set, and if so, step 424 checks to see if the ACS flag is set.
At step 25, the color counter (I3) is set to a color data creation inhibited state, and the process proceeds to step 426.

As a result, the color data is no longer created by the color discrimination means (12). If the ACS flag is not set in step 424, proceed to step 424.
Proceed to step 6.

In step 426, it is checked whether the EE flag is set, and if it is not set, the process is terminated. If it is set, in step 427, the concentration discrimination storage means (14) is set to a state in which EE data creation is prohibited. Then, the process ends. This prevents the color discrimination means (12) from creating EE data in the storage means (14).

When the ACS mode and EE mode are set in page continuous copying mode and the copy button is pressed, the forward flag is set and the process proceeds from step 301 to 302 in FIG. 5, where the scanner forward signal is output and the scanner (7) starts preliminary scanning (time tl in FIG. 7). Scanner (7)
When reaches the leading edge of the document (time t2 in FIG. 7), the process advances to steps 303 to 304 in FIG. 5, where the data creation flag is set, the counter CNA is cleared, a clear signal is output, and the color counter (t3) and the EE data in the storage means (14) is cleared. Once the data creation flag is set, steps 404 to 40 in FIG.
5, the counter CNA starts counting, and the creation of color data in the color counter (13) and EE data in the storage means (14) starts. Then, until the scanner (7) reaches the rear edge of the first page of the document,
Data creation continues.

When the scanner (7) reaches the rear edge of the first page of the document (
At time t3) in FIG. 7, the counter CNA becomes equal to the constant CNTA and the process proceeds from step 410 to 411 in FIG. 6, where the counter CNA is cleared and the color data of the first page is The color data and EE data are checked, and the color data and EE data are cleared in order to create the second page data.

When the preliminary scanning of the first page is completed, the snapshot mode is set and the snapshot flag is set, so the process proceeds to steps 418 to 419 in FIG. Also, at this time, since the first document flag has been set, the process proceeds from step 419 to step 420 in the figure, resets the first document flag, and ends the process. Then, the flowchart shown in the figure is repeated from the beginning, and data for the second page is created in the same manner as described above until the scanner (7) reaches from the leading edge to the trailing edge of the second page of the document.

When the scanner (7) reaches the rear edge of the second page of the document (
At time t4) in FIG. 7, the counter CNA becomes equal to the constant CNTA, and the process proceeds from step 41O to step 411 in FIG. Data and EE data are cleared.

Even when the preliminary scanning of the second page is completed, the snapshot flag is set, so steps 418 to 4 in FIG.
The process proceeds to step 19, but since the first document flag was reset in step 420 when the preliminary scanning of the first page was completed, the process proceeds from step 419 to step 421, the data creation flag is reset, and the first document flag is set. The counter CNA is cleared, and the creation of color data and EE data is prohibited. Then, since the data creation flag is reset, even if the flow chart of FIG. 6 is proceeded to next time, no processing for data creation and checking from step 405 onwards will be performed.

When the preliminary scanning of the second page is completed and the scanner (7) reaches the rear end of the document (time t5 in FIG. 7), the process proceeds from steps 308 to 309 in FIG. 5, and a scanner return signal is output. The scanner (7) returns to its home position.

This completes the preliminary scanning, and the color data of the first page determines the color to be used for the first page, the color data of the second page determines the color to be used for the second page, and based on this, page continuous copying is performed. A copy is made. This determination of the color to be used is performed by comparing the count value of the color counter (13) with a predetermined threshold value close to ◯, so that only colors whose count value is greater than the threshold value are used. For example, if the first page is red and blue, the count values of the red counter (13a) and the blue counter (13b) are quite large, and the count value of the black counter (L3c) is almost O, so the first page , red and blue will be selected and these two-color copies will be made. If the second page is black,
The count value of the black counter (13c) is quite large,
Red counter (13a) and blue counter (L3b)
Since the count value of is almost O, only black is selected for the second page, and monochrome copying thereof is performed.

Also, when copying the first page, the density is automatically adjusted for each color based on the EE data of the first page, and when copying the second page, the density is adjusted to 7a degrees for each color based on the EE data of the second page. is automatically adjusted.

Note that if you are not in continuous shooting mode, the continuous shooting flag will not be set when the first page is scanned, so
The process proceeds from step 418 to step 421 in FIG. 6, and the preliminary scan is completed.

Further, if only one of the ACS mode and the EE mode is set, only data creation and data checking for the set mode are performed in the preliminary scan, as is clear from the flowchart of FIG.

In the above embodiment, the color data and EE data of the first page and that of the second page are stored in the same color counter (13).
However, if preliminary scanning is to be performed at high speed, the color counter and storage means for the first page and the storage means for the second page should be provided separately. You can.

Effects of the Invention According to the image forming apparatus of the present invention, as described above, when copying in the automatic density adjustment mode in the page continuous copying mode, two
Even if there is an extreme difference in density between pages of originals, each page of the original can be copied under optimal conditions according to the density of each original.

[Brief explanation of drawings]

FIG. 1 is a schematic overall configuration diagram of an electrophotographic color copying machine showing an embodiment of the present invention, FIG. 2 is a vertical sectional view schematically showing the mechanical structure of the main parts of the copying machine, and FIG. FIG. 4 is a flowchart showing an example of routine processing for setting the page snapshot mode, FIG. 4 is a flowchart showing one example of routine processing for mode setting, and FIG. 5 is an example of the routine for preliminary scanning. FIG. 6 is a flowchart showing an example of routine processing for determining the color state and density state, and FIG. 7 is a time chart showing the operation of the main parts of the copying machine during preliminary scanning. (1)...Reading section, (2)...Image processing section, (
3)...Recording section, (4)...Operation section, (5)...
Control section, (14a) (14b) (14c)...density determination storage means, (15)...photosensitive drum (image forming body). that's all

Claims (2)

[Claims] (1) A reading section that scans and reads the original; an image processing section that processes the output of the reading section and outputs image information;
It is equipped with a recording section that forms an image in the image area of the image forming body based on image information and transfers it to transfer paper, an operation section for setting conditions, and a control section that controls these, and can handle two pages of originals. Continuous page mode copying that copies one page at a time onto two sheets of transfer paper, and automatic density adjustment that automatically adjusts the copy density by determining the density status of the original by preliminary scanning before the main scanning of the original. In image forming apparatuses that are now capable of copying modes, when copying in automatic density adjustment mode in page continuous copying mode, the density state of the first page and the density state of the second page are determined separately by preliminary scanning. , the copy density of the first page is automatically adjusted depending on the density state of the first page, and the copy density of the second page is automatically adjusted depending on the density state of the second page. Image forming device. (2) The reading unit reads the document by separating it into at least two colors, the image processing unit outputs image information of at least two colors, and the recording unit forms an image of at least two colors, and automatic density adjustment is used. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus determines the density state of each color and adjusts the copy density when copying in the mode.