JP2024064742A - Image formation device and image formation method - Google Patents

Abstract

To enable a user to clearly recognize an overlappedly formed image even when further overlapping an image on a recording sheet having the image already formed for image formation, and to make the recording sheet having the image already formed economically reusable.SOLUTION: In an image formation device 10, a control unit 29 is configured to: cause an image reading unit 11 to read an image of a first manuscript of a copy object, and determine a content in the image of the first manuscript; cause the image reading unit 11 to read an image of a second manuscript to be reused as the recording sheet, and determine a color area in the image of the second manuscript; determine a color area of the image of the second manuscript which the content in the image of the first manuscript overlaps when overlapping the image of the first manuscript on the image of the second manuscript; set a color of the content overlapping the determined color area based on combination data CD; and cause an image formation unit 12 to form the content in the image of the first manuscript on the recording sheet of the second manuscript in the set color.SELECTED DRAWING: Figure 2

Description

The present invention relates to an image forming apparatus and method for forming an image on paper, and in particular to a technology for supporting the reuse of paper on which an image has been formed.

In an image forming device, an image reading unit reads an image of an original document, and an image forming unit forms the image of the original document that has been read onto recording paper. Since a large amount of recording paper is consumed, it is desirable to reuse at least a portion of it.

For example, the printer described in Patent Document 1 uses a scanner to scan pre-printed paper to identify the print area, and prints the identified print area on the paper with white ink or white toner, turning the paper into reusable blank paper before outputting it.

US 2017/0050455 A1

However, when printing the printing area of pre-printed paper with white ink or white toner to make the paper blank and reusable, as in Patent Document 1, the larger the printing area, the greater the consumption of white ink or white toner, which is uneconomical.

The present invention has been developed in consideration of the above circumstances, and aims to enable a user to clearly recognize the overlapping image even when an image is formed on a recording paper on which an image has already been formed, and to economically reuse the recording paper on which an image has already been formed.

An image forming apparatus according to one aspect of the present invention includes an image reading unit that reads an image of an original, an image forming unit that forms the image of the original on a recording sheet, and a control unit that inputs an image of a first original to be copied, determines the content in the image of the first original, and causes the image reading unit to read an image of a second original to be reused as a recording sheet, detects color areas in the image of the second original, determines the color area in the image of the second original where the content in the image of the first original overlaps when the image of the first original is superimposed on the image of the second original, sets the color of the content to be superimposed on the determined color area based on preset color combination data to a color that is predetermined to have good visibility for the color area in the image of the second original, and causes the image forming unit to form the content in the image of the first original on the recording sheet of the second original in the set color.

An image forming method according to one aspect of the present invention includes the steps of inputting an image of a first original to be copied and reading an image of a second original to be reused as recording paper, determining the content in the image of the first original and detecting color areas in the image of the second original, determining color areas in the image of the second original where the content in the image of the first original overlaps when the image of the first original is superimposed on the image of the second original, and setting the color of the content that overlaps the determined color area based on preset color combination data to a predetermined color that has good visibility relative to the color area in the image of the second original, and forming the content in the image of the first original on the recording paper of the second original in the set color.

According to the present invention, even when an image of a first document is formed by overlaying an image of various colors formed on a second document as recording paper, the user can clearly recognize the image of the first document. This allows an image to be formed on the surface of a recording paper on which an image has already been recorded, rather than on the back side on which an image has not been formed, making it possible to economically reuse a second document as recording paper on which an image has already been recorded.

1 is a cross-sectional view showing an image forming apparatus according to an embodiment of the present invention. 1 is a block diagram showing an image forming apparatus according to an embodiment of the present invention; FIG. 4 is a diagram showing a home screen displayed on a display unit of the image forming apparatus. FIG. 13 is a diagram conceptually illustrating an example of color combination data. FIG. 2 shows a known RYB color wheel and an inverted RYB color wheel used to create color combination data. A flowchart showing a control procedure for setting the color of content in an image of a first original that overlaps a color area in an image of a second original, and forming the content in the image of the first original in the set color on the recording paper of the second original. 6B is a flowchart showing a control procedure subsequent to FIG. 6A. 13 is a diagram showing a screen of a display unit on which a message is displayed prompting the reading of a first document to be copied. FIG. 13 is a diagram showing a screen of a display unit on which a message is displayed to prompt the user to read a second document to be reused as recording paper. FIG. 13 is a diagram showing a screen of a display unit on which a message prompting a user to place a second document on the manual feed tray is displayed; FIG. FIG. 2 is a diagram illustrating an example of an image of a first original to be copied. 11 is a diagram illustrating an example of an image of a second document to be reused as a recording sheet. FIG. FIG. 13 is a diagram showing a state in which an image of a first original and an image of a second original are superimposed on each other. 13 is a diagram showing a screen of a display unit on which an image of a first original and an image of a second original are displayed superimposed on each other; FIG. 13 is a diagram showing a state in which the image of the first original and the image of the second original are superimposed on each other, and a screen of a display unit on which each color of the content is displayed. FIG. FIG. 13 is a diagram showing a state in which the content in the image of the first document is divided into each content portion.

The image forming device according to one embodiment of the present invention will be described below with reference to the drawings.

Figure 1 is a cross-sectional view showing an image forming apparatus according to one embodiment of the present invention. As shown in Figure 1, the image forming apparatus 10 of this embodiment is an MFP (multi-function peripheral) that combines multiple functions such as a copy function and a printer function. This image forming apparatus 10 includes an image reading unit 11 and an image forming unit 12.

The image reading unit 11 has an image sensor (CCD sensor) that optically reads the image of the document, and the analog output of this image sensor is converted into a digital signal to generate image data representing the image of the document.

The image forming unit 12 forms an image represented by the image data on a recording sheet, and includes an image forming unit 3M for magenta, an image forming unit 3C for cyan, an image forming unit 3Y for yellow, and an image forming unit 3Bk for black. In each of the image forming units 3M, 3C, 3Y, and 3Bk, the surface of the photosensitive drum 4 is uniformly charged, the surface of the photosensitive drum 4 is exposed to light, an electrostatic latent image is formed on the surface of the photosensitive drum 4, the electrostatic latent image on the surface of the photosensitive drum 4 is developed into a toner image, and the toner image on the surface of the photosensitive drum 4 is primarily transferred to the intermediate transfer belt 5. As a result, a color toner image is formed on the intermediate transfer belt 5. This color toner image is secondarily transferred to the recording sheet P transported from the paper feed unit 14 through the transport path 8 in the nip area N between the intermediate transfer belt 5 and the secondary transfer roller 6.

The paper feed section 14 is equipped with multiple paper feed cassettes 7 and a manual feed tray 9, and recording paper P is transported and supplied to the transport path 8 from one of the paper feed cassettes 7, or from the manual feed tray 9. This recording paper P is sent to the transport path 8, and the color toner image on the intermediate transfer belt 5 is secondarily transferred to the recording paper P in the nip area N between the intermediate transfer belt 5 and the secondary transfer roller 6.

After this, the recording paper P is heated and pressurized in the fixing device 15, the toner image on the recording paper P is fixed by thermal compression, and the recording paper P is then discharged to the discharge tray 17 via the discharge rollers 16.

Next, FIG. 2 is a block diagram showing the main internal configuration of the image forming device 10 of this embodiment. As shown in FIG. 2, the image forming device 10 of this embodiment includes an image reading unit 11, an image forming unit 12, a display unit 21, an operation unit 22, a touch panel 23, an image memory 26, a storage unit 27, and a control unit 28. These components are capable of transmitting and receiving data or signals to and from each other via a bus.

The display unit 21 is composed of a liquid crystal display (LCD) or an organic light-emitting diode (OLED) display.

The operation unit 22 includes physical keys such as a numeric keypad, a decision key, and a start key. Instructions are input to the operation unit 22 by the user's operation.

A touch panel 23 is disposed on the screen of the display section 21. The touch panel 23 is a so-called resistive film type or capacitive type touch panel, which detects contact (touch) of a user's finger or the like with the touch panel 23 together with the contact position, and outputs a detection signal indicating the coordinates of the contact position to the control section 29 (described later) of the control unit 28. The touch panel, as part of the operation section 22, accepts input of instructions from the user.

The storage unit 27 is a large-capacity storage device such as an SSD (Solid State Drive) or HDD (Hard Disk Drive), and stores various application programs and various data.

The control unit 28 is composed of a processor, a RAM (Random Access Memory), a ROM (Read Only Memory), etc. The processor is, for example, a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or an MPU (Micro Processing Unit). The control unit 28 functions as a control unit 29 by the processor executing a control program stored in the ROM or the memory unit 27.

The control unit 29 controls the image forming device 10. The control unit 28 is connected to the image reading unit 11, the image forming unit 12, the display unit 21, the operation unit 22, the touch panel 23, the image memory 26, and the storage unit 27. The control unit 29 controls the operation of these components and transmits and receives signals and data between these components.

The control unit 29 serves as a processing unit that executes various processes necessary for image formation by the image forming device 10.

The control unit 29 also has a function of controlling the display operation of the display unit 21. Furthermore, the control unit 29 accepts operation instructions input by the user based on a detection signal output from the touch panel 23 or the operation of a physical key of the operation unit 22. For example, the control unit 29 accepts touch operations on a GUI (Graphical User Interface) displayed on the screen of the display unit 21 through the touch panel 23.

In the image forming device 10 configured as above, the control unit 29 displays a home screen HG as shown in FIG. 3 on the display unit 21 while waiting for a user to operate the operation unit 22, the touch panel 23, etc. This home screen HG displays function keys K31a, 31b, ..., 31h, etc. for selecting a copy job, a scan job, ..., a paper reuse job, etc.

For example, a user places an original on the image reading unit 11, touches the function key K31a on the home screen HG displayed on the display unit 21 to select a copy job, and then operates the start key on the operation unit 22. This causes the operation unit 22 to accept an instruction to execute a copy operation. In response to the instruction to execute a copy operation, the control unit 29 executes the copy job, causes the image reading unit 11 to read the image of the original, stores image data representing the image of the original in the image memory 26, inputs the image data to the image formation unit 12, and causes the image formation unit 12 to form the image of the original on recording paper.

The user also touches the function key K31h on the home screen HG displayed on the display unit 21 to select the recording paper reuse job. This causes the operation unit 22 to receive an instruction to reuse recording paper. In this case, the control unit 29, in response to the instruction to reuse recording paper, sequentially displays the operating procedures for reusing recording paper on the screen of the display unit 21, and activates the function of reusing recording paper in response to the user's execution of the operating procedures.

In a recording paper reuse job, the control unit 29 causes the image reading unit 11 to read the image of the first document to be copied, and determines the content in the image of the first document. Then, the control unit 29 causes the image reading unit 11 to read the image of the second document to be reused as recording paper, and detects the color area in the image of the second document. Furthermore, the control unit 29 determines the color area in the image of the second document where the content in the image of the first document overlaps when the image of the first document is superimposed on the image of the second document, and sets the color of the content to be superimposed on the determined color area based on the preset color combination data CD to a color that is predetermined to have good visibility for the determined color area in the image of the second document. Furthermore, the control unit 29 causes the image forming unit 12 to form the content in the image of the first document in the set color on the recording paper of the second document.

This allows the user to clearly recognize the image of the first document, even when the image of the first document is formed by overlaying it on top of the various color images formed on the second document as recording paper. This allows the image to be formed on the surface of the recording paper on which an image has already been recorded, rather than on the back side on which an image has not been formed, making it possible to economically reuse the second document as recording paper on which an image has already been recorded.

In addition, the image of the first original to be copied may be input from an external USB memory or the like, instead of reading the image of the first original using the image reading unit 11.

As shown in Figure 4, for example, the color combination data CD is obtained by arranging the colors RC1-RC9 of the color area in the image of the second original document to be reused as recording paper horizontally and arranging the colors CC1-CC9 of the content in the image of the first original document to be copied vertically, and evaluating the visibility of the content color against the color of the color area for all combinations of the colors RC1-RC9 of the color area and the colors CC1-CC9 of the content. The visibility evaluation is either "fair" indicating good visibility or "poor" indicating poor visibility.

In this color combination data CD, for example, if the color of the content is an inverse color or an approximate color of the inverse color with respect to the color of the color area, or if there is a large difference in brightness between the color area and the content, visibility is considered to be "OK." Conversely, if the color of the content is the same color or an approximate color of the same color with respect to the color area, or there is a small difference in brightness between the color area and the content, visibility is considered to be "NO."

For example, the visibility of the content color CC3 (yellow) is "fair" for the color region color RC1 (red). Therefore, in the color region of color RC1 (red), the visibility of the content of color CC3 (yellow) is good, and the content is easy to see.

In addition, for the color RC3 (yellow) in the color region, the visibility of content color CC2 (orange) or content color CC4 (green) is "not possible." Therefore, in the color region of color RC3 (yellow), the visibility of content color CC2 (orange) or content color CC4 (green) is poor, making the content difficult to see.

Such color combination data is created based on the known RYB color wheel W1 and inverted RYB color wheel W2, for example, as shown in Figure 5.

In addition, since the image forming device 10 of this embodiment does not use white toner, the color of the content (white) in the color combination data CD is not used. In an image forming device that uses white toner in addition to M (magenta), C (cyan), Y (yellow), and Bk (black), it is possible to apply the color of the content (white) in the color combination data CD.

Next, the control procedure for setting the color of the content in the image of the first original to be overlaid on the color area in the image of the second original as described above and forming the content in the image of the first original in the set color on the recording paper of the second original by the image forming unit 12 will be described with reference to the flowcharts shown in Figures 6A and 6B.

First, the control unit 29 displays the home screen HG shown in FIG. 3 on the display unit 21 and waits for the user to input an instruction to the operation unit 22 corresponding to the function key K31h indicating the recording paper reuse job on the home screen HG (S101).

When the user touches another function key on the home screen HG, the control unit 29 accepts an instruction corresponding to the other function key input through the touch panel 23 (S101 "No"), and executes a process corresponding to this instruction (S102). For example, when the user places a document on the image reading unit 11, touches the function key K31a to select a copy job, and operates the start key on the operation unit 22, an instruction to execute a copy operation is input to the touch panel 23, and the control unit 29 executes the copy job in response to the instruction to execute the copy operation, causes the image reading unit 11 to read the image of the document, and causes the image forming unit 12 to form the image of the document on recording paper.

In addition, when the user touches the function key K31h on the home screen HG, the control unit 29 accepts the recording paper reuse instruction corresponding to the function key K31h input through the touch panel 23 (S101 "Yes"). In accordance with this instruction, the control unit 29 starts a recording paper reuse job (S103) and displays a message M1 on the screen of the display unit 21 prompting the user to read the first document to be copied, as shown in FIG. 7 (S104).

The user sees message M1, places the first document to be copied in image reading unit 11, and operates the start key of operation unit 22. In response to the operation of the start key, control unit 29 causes image reading unit 11 to read the image of the first document, stores image data representing the image of the first document in image memory 26 (S105), and displays message M2 on the screen of display unit 21 encouraging the user to read the second document to be reused as recording paper, as shown in FIG. 8 (S106).

The user sees message M2, places the second original to be reused as recording paper in image reading unit 11, and operates the start key of operation unit 22. In response to the user's operation of the start key, control unit 29 causes image reading unit 11 to read the image of the second original in accordance with the reading instruction input to operation unit 22, and stores image data representing the image of the second original in image memory 26 (S107).

Then, the control unit 29 displays a message M3 on the screen of the display unit 21, as shown in FIG. 9, which prompts the user to place the second document to be reused as recording paper on the manual feed tray 9 of the image forming device 10 (S108). In addition to the message M3, an OK key K11 is also displayed on the screen of the display unit 21.

The user sees the message M2, removes the second document to be reused as recording paper from the image reading unit 11, places this second document on the manual feed tray 9, and touches the OK key K11.

The control unit 29 waits for input of an instruction corresponding to the OK key K11 (S109 "No"), and when input of an instruction corresponding to the OK key K11 is received via the touch panel 23 (S109 "Yes"), it determines that the second document has been placed on the manual feed tray 9 (S110).

Then, the control unit 29 judges each content in the image of the first original based on the image data representing the image of the first original stored in the image memory 26 (S111). For example, the control unit 29 judges each content (character strings, figures, etc.) in the image of the first original based on the image data representing the image of the first original using a well-known AI (Artificial Intelligence)-OCR (Optical Character Reader). At this time, the control unit 29 maintains the layout of each content in the image of the first original as it is. As a result, each content CT1, CT2, CT3, ... in the image G1 of the first original as shown in FIG. 10 is judged.

The control unit 29 also detects each color area in the image of the second original based on image data representing the image of the second original stored in the image memory 26 (S112). For example, the control unit 29 extracts an area consisting of pixels of the same color based on the image data representing the image of the second original, and detects the extracted area as a color area if the size of the extracted area is equal to or larger than a preset certain size. At this time, the control unit 29 maintains the layout of each color area in the image of the second original as it is. This allows the color areas KR1 and KR2 in the image G2 of the second original to be determined as shown in FIG. 11.

The control unit 29 determines the color areas in the image of the second original where each content in the image of the first original overlaps when the image of the first original is superimposed on the image of the second original (S113). For example, as shown in FIG. 12, the color area KR1 in the image G2 of the second original where each content CT1, CT3 in the image G1 of the first original overlaps is determined, and the color area KR2 in the image G2 of the second original where each content CT4, CT5 in the image G1 of the first original overlaps is determined.

The control unit 29 refers to the color combination data CD shown in FIG. 4 for each content in the image of the first original document, and sets the color of the content that is marked as "OK" for the color of the color area that overlaps the content as a color that has been predetermined as having good visibility for the color area (S114).

Then, the control unit 29 causes each content and each color area of the respective set colors to be displayed on the screen of the display unit 21 with the image of the first original and the image of the second original superimposed (S115). As a result, on the screen of the display unit 21, for example, as shown in FIG. 13, each content CT1, CT3 overlapping with color area KR1 is displayed in the respective set colors, and each content CT4, CT5 overlapping with color area KR2 is displayed in the respective set colors. As described above, the color of each content is set to a color that is "OK" for the color of the color area overlapping the content in the color combination data CD for each content, so that the visibility of each content is improved.

In addition to the superimposed image of the first document and the image of the second document, the screen of the display unit 21 also displays an OK key K21, a correction key K22, and a cancel key K23.

When the user sees the state displayed on the screen of the display unit 21 and judges that the state is good, he or she touches the OK key K21. When the control unit 29 receives an input of an approval instruction corresponding to the OK key K21 through the touch panel 23 (S116 "OK"), it generates an image (similar to the image showing the state displayed on the screen of the display unit 21) in which each content of the image of the first original is superimposed on each color area of the second original, stores it in the image memory 26, and causes the image forming unit 12 to pull out the recording paper of the second original from the manual feed tray 9, and forms the image of the superimposed state on the recording paper of the second original (S117). After this, the control unit 29 discharges the recording paper of the second original after the image formation to the discharge tray 17. After this, the control procedure shown in FIG. 6A and FIG. 6B is terminated. As a result, an image in which each content of the image of the first original is superimposed on each color area of the second original in the above-mentioned set color is formed on the recording paper of the second original.

In addition, in S116, if the user sees the state displayed on the screen of the display unit 21 and decides to correct this state, he or she touches the correction key K22. When the control unit 29 receives a correction instruction input corresponding to the correction key K22 through the touch panel 23 (S116 "Correction"), it causes the screen of the display unit 21 to display each color CC1 to CC9 of the content lined up vertically in the color combination data CD, the OK key K31, and the NG key K32, in addition to the state in which each content of each set color in the image of the first original overlaps each color area of the second original as shown in FIG. 14 (S118).

The user touches an image showing one of the contents on the screen to input a selection instruction to select the content, and then touches one of the colors CC1 to CC9 of the content to input a color designation instruction to specify the color. The control unit 29 selects the content according to the selection instruction input through the touch panel 23 (S119), and then changes the color of the selected content on the screen of the display unit 21 to a color according to the color designation instruction (S120).

Whenever the user repeatedly selects content and specifies a color, the control unit 29 changes the color of the selected content on the screen of the display unit 21 to the specified color each time in the same manner as described above (S119, S120).

At this time, the control unit 29 may divide the content into a plurality of content parts and set a color for each divided content part according to an instruction input by the user. For example, a division instruction to divide the content CT5 into the arbitrary content part M1 and another content part M2 is input to the touch panel 23 by a touch operation by the user, for example, a swipe operation on an arbitrary content part M1 of the content CT5, as shown in FIG. 15, and then an instruction to specify red as the color of the arbitrary content part M1 is input to the touch panel 23 by a first touch operation on any of the content colors CC1 to CC9, and further an instruction to specify blue as the color of the other content part M2 is input to the touch panel 23 by a second touch operation on any of the content colors CC1 to CC9. At this time, the control unit 29, in accordance with the above-mentioned division instruction, divides the content CT5 into the arbitrary content portion M1 that was swiped and another content portion M2, and in accordance with the above-mentioned instruction to specify red, sets the color of the arbitrary content portion M1 to the red specified by the first touch operation, and in accordance with the above-mentioned instruction to specify blue, sets the color of the other content portion M2 to the blue specified by the second touch operation.

After changing the color of the content, the user touches the OK key K31. When the control unit 29 receives an instruction input corresponding to the OK key K31 through the touch panel 23 (S121 "OK"), it generates an image showing the state in which each content of the set color in the image of the first original is superimposed on each color area of the second original, that is, the state in which it is displayed on the screen of the display unit 21, stores it in the image memory 26, and causes the recording paper of the second original to be pulled out from the manual feed tray 9 by the recording paper transport mechanism and image forming unit 12, forms the generated image on the recording paper of the second original by the image forming unit 12, and discharges the recording paper of the second original to the discharge tray 17 (S122). After this, the control procedure shown in Figures 6A and 6B is terminated.

Furthermore, when the user touches the NG key K32 and the control unit 29 receives an instruction input corresponding to the NG key K32 via the touch panel 23 (S121 "NG"), the control unit 29 invalidates the color of the content changed in S120, erases each color CC1 to CC9 of the content on the screen of the display unit 21, and returns the color of each content to its original color (S114). Then, the control unit 29 causes the screen of the display unit 21 to display a state in which each content of the set color in the image of the first original overlaps with each color area of the second original (S115). After this, the processing from S116 onwards is carried out.

When the user touches the cancel key K23 and the control unit 29 receives an instruction input corresponding to the cancel key K23 through the touch panel 23 (S116 "Cancel"), the control procedure shown in Figures 6A and 6B immediately ends. In this case, the image of the first original is not formed on the recording paper of the second original.

In this way, the recording paper reuse job determines the content in the image of the first original to be copied, determines the color areas in the image of the second original to be reused as recording paper, determines the color areas in the image of the second original where the content in the image of the first original overlaps when the image of the first original is overlaid on the image of the second original, sets the color of the content that overlaps the determined color area based on the color combination data CD, and forms the content in the image of the first original on the recording paper of the second original in the set color.

As described above, according to this embodiment, even when an image is formed on top of a recording paper on which an image has already been formed, the user can clearly recognize the image formed on top of the recording paper, and the recording paper on which an image has already been formed can be economically reused.

Note that the configuration and processing of the above embodiment described using Figures 1 to 15 are merely examples of the present invention, and are not intended to limit the present invention to these configurations and processing.

10 Image forming apparatus 11 Image reading section 12 Image forming section 21 Display section 22 Operation section 23 Touch panel 26 Image memory 27 Storage section 28 Control unit 29 Control section

Claims (6)

an image reading unit that reads an image of a document;
an image forming section for forming an image of the document on a recording sheet;
an image forming apparatus comprising: a control unit that inputs an image of a first original to be copied, determines content in the image of the first original, and also causes the image reading unit to read an image of a second original to be reused as recording paper to detect color areas in the image of the second original, determines the color area in the image of the second original where the content in the image of the first original overlaps when the image of the first original is overlaid on the image of the second original, sets the color of the content to be overlaid on the determined color area based on predetermined color combination data to a predetermined color that has good visibility for the color area in the image of the second original, and causes the image forming unit to form the content in the image of the first original on the recording paper of the second original in the set color. A display unit;
an operation unit into which an instruction is input by a user operation,
The image forming device of claim 1, wherein the control unit causes the display unit to display an image showing a state in which the content of the set color in the image of the first original overlaps the color area of the second original, and when an instruction to form the first original is input to the operation unit, the image forming unit causes the content in the image of the first original to be formed in the set color on the recording paper of the second original. The image forming apparatus according to claim 2, wherein the control unit causes the display unit to display an image showing a state in which the content of the set color in the image of the first document overlaps with the color region of the second document, changes the color of the content based on the color combination data in response to an instruction input to the operation unit, and causes the display unit to display an image showing a state in which the content of the changed color in the image of the first document overlaps with the color region of the second document. an operation unit into which an instruction is input by a user operation,
The control unit divides the content of the set color in the image of the first original into multiple content parts in response to instructions input to the operation unit, and for each content part, determines a color area in the image of the second original where the content part in the image of the first original overlaps when the image of the first original is overlaid on the image of the second original, sets the color of the content to be overlaid on the determined color area for each content part based on the combination data, and causes the image forming unit to form each of the content parts in the image of the first original on the recording paper of the second original in the respective set colors. An image forming device according to any one of claims 1 to 4, wherein the color combination data sets the color of the content to be an inverted color of the color area, or sets the brightness of the content to be significantly different from the brightness of the color area. inputting an image of a first document to be copied and reading an image of a second document to be reused as recording paper;
determining a content in the image of the first original and detecting a color area in the image of the second original, determining a color area in the image of the second original where the content in the image of the first original overlaps when the image of the first original is superimposed on the image of the second original, and setting a color of the content that overlaps the determined color area based on preset color combination data to a predetermined color that has good visibility relative to the color area in the image of the second original;
forming the content in the image of the first original on a recording sheet of the second original in the set color.