JP2013070221A - Image forming apparatus and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technique capable of suppressing the consumption amount of a concealment coloring agent, while keeping printing quality for making a user satisfied.SOLUTION: An image forming apparatus includes: a print image data generation part 133 for generating print image data including first image data for printing a first image, concealment image data for printing a concealment image to be printed so as to be overlapped with the first image, and second image data for printing a second image, on the basis of print data including the first image and the second image to be printed so as to be overlapped with at least a part of the first image; and a printing part 145 for performing printing on the basis of the print image data. The print image data generation part 133 specifies the use level of a coloring agent in printing a concealment image in accordance with the kind of a second image. The printing part 145 prints a concealment image in accordance with the specified use level.

Description

  The present invention relates to an image forming apparatus and an image forming method.

A technology such as an electronic pen system manufactured by ANOTO (registered trademark) Corporation and GRID INPUT (registered trademark) manufactured by Gridmark Co., Ltd. forms a pattern image of a predetermined dot pattern on a medium, and an infrared image is formed on the pattern image. There is a technique for acquiring information from this pattern image by irradiating light or ultraviolet light and reading the reflected light with an optical reading means. For example, in GRID OPEN, a dot code is indicated by a dot pattern, and by reading such a dot pattern, it is possible to acquire the indicated character, sound, image, or the like.
In the technique as described above, a number of fine dots are printed on the medium, so that the print quality of a display image printed thereon may be deteriorated due to the dots. For this reason, there is a technique for improving the printing quality by printing characters and images after the dot pattern image is filled with a concealing colorant (see, for example, Patent Document 1). Usually, the opaque colorant is opaque toner or opaque ink having a color close to white or medium color. In this technique, even when high print quality is not required, the concealing colorant is consumed in the same manner as when high print quality is required.

JP 2010-224144 A

However, in the conventional technique, all the dot patterns are painted in the same manner with a concealing colorant. For this reason, the amount of the concealing colorant used is large and wasted.
Therefore, an object of the present invention is to provide a technique capable of suppressing the consumption of the concealing colorant while maintaining the print quality that can be satisfied by the user.

  The image forming apparatus according to one aspect of the present invention is based on print data including a first image and a second image printed over at least a part of the first image. First image data for printing an image, concealment image data for printing a concealment image to be printed over the first image, and second image data for printing the second image A print image data generation unit that generates print image data including a print unit that performs printing based on the print image data, and the print image data generation unit is configured to respond to a type of the second image. The use level of the colorant for printing the concealed image is specified, and the printing unit prints the concealed image according to the specified use level.

  According to one embodiment of the present invention, it is possible to suppress the consumption of the concealing colorant while maintaining a print quality that can be satisfied by the user.

1 is a schematic configuration diagram of a printing system according to Embodiments 1 and 2. FIG. FIG. 2 is a block diagram schematically showing a configuration of a host device in the first embodiment. 1 is a block diagram schematically showing a configuration of a printing apparatus according to Embodiment 1. FIG. FIG. 3 is a schematic diagram of a dot pattern image in the first embodiment. 6 is a schematic diagram illustrating image toner amount level information according to Embodiment 1. FIG. 3 is a schematic diagram of print image data according to Embodiment 1. FIG. 2 is a schematic configuration diagram illustrating an example of a configuration of a printing unit according to Embodiment 1. FIG. 3 is a schematic diagram illustrating an example of a reading device according to Embodiment 1. FIG. 3 is a flowchart illustrating processing performed by the host device according to the first embodiment. 4 is a flowchart illustrating processing performed by a print image data generation unit of the printing apparatus according to the first embodiment. 4 is a longitudinal sectional view illustrating an example of a toner layer formed on a medium in Embodiment 1. FIG. FIG. 4 is a block diagram schematically illustrating a configuration of a printing apparatus according to a second embodiment. 6 is a schematic diagram showing area toner amount level information in Embodiment 2. FIG. 10 is a flowchart illustrating processing performed by a print image data generation unit of a printing apparatus according to Embodiment 2.

Embodiment 1 FIG.
In the first embodiment, when the pattern image of the dot pattern that is the first image is filled with the concealment toner that is the concealment colorant, it is used according to the type of the display image that is the second image. This is a technique for suppressing the amount of concealment toner consumed by adjusting the amount of toner to be applied. Embodiment 1 will be described below with reference to the drawings.

(Description of configuration)
FIG. 1 is a schematic configuration diagram of a printing system 100 according to the first embodiment. The printing system 100 includes a host device 110 and a printing device 130 as an image forming device. The host device 110 and the printing device 130 are connected by an electrical connection means such as a signal cable 170. The reference numerals in parentheses in FIG. 1 indicate the configuration in the second embodiment.

  When the host apparatus 110 receives a print execution instruction from the user, the host apparatus 110 transmits the instructed print data to the printing apparatus 130. FIG. 2 is a block diagram schematically showing the configuration of the host device 110. The host device 110 includes an application unit 111, a driver unit 112, an IF (InterFace) unit 115, and an input unit 116.

  The application unit 111 generates output data including a color display image and a dot pattern image to be printed based on information input by the user via the input unit 116. Here, in the present embodiment, the display image is an image that is required to be visualized by being printed on the medium, and the dot pattern image is printed on the medium, but is not necessarily visualized. It is an image that is not required. The display image includes at least one of text (character), graphic (line drawing), and picture (picture or photo). Then, the application unit 111 gives the generated output data to the driver unit 112.

The driver unit 112 performs processing for generating print data from the output data generated by the application unit 111 and transmitting the print data. As illustrated in FIG. 2, the driver unit 112 includes a PDL (Page Description Language) data generation unit 113 and a data transmission unit 114.
The PDL data generation unit 113 generates print data described in PDL from the output data generated by the application unit 111.
The data transmission unit 114 performs processing for transmitting the print data generated by the PDL data generation unit 113 to the printing apparatus 130 via the IF unit 115.

The IF unit 115 transmits and receives data to and from the printing apparatus 130. For example, the IF unit 115 transmits print data to the printing apparatus 130.
The input unit 116 receives input of information from the user.

The host device 110 includes, for example, a CPU (Central Processing Unit), a memory, an external storage device such as an HDD (Hard Disk Drive), and a portable storage such as a CD (Compact Disk) and a DVD (Digital Versatile Disk). A general computer including a reading / writing device for reading and writing information from / to a medium, an input device such as a keyboard and a mouse, an output device such as a display, and an interface for connecting to the printing device 130 realizable.
For example, the application unit 111 and the driver unit 112 can be realized by loading a predetermined program stored in an external storage device into a memory and executing the program by the CPU. The input unit 116 uses the input device by the CPU. The IF unit 115 can be realized by the CPU using the interface.

  FIG. 3 is a block diagram schematically showing the configuration of the printing apparatus 130. The printing apparatus 130 includes an IF unit 131, a communication unit 132, a print image data generation unit 133, a control unit 144, and a printing unit 145.

The IF unit 131 transmits and receives data to and from the host device 110. For example, the IF unit 131 receives print data from the host device 110.
The communication unit 132 performs communication processing via the IF unit 131. For example, the communication unit 132 receives the print data received by the IF unit 131 and gives the print data to the print image data generation unit 133.

  The print image data generation unit 133 generates print image data indicating an image to be formed by the printing unit 145 from the print data transmitted from the host device 110. As shown in FIG. 3, the print image data generation unit 133 includes a print data analysis unit 134, a dot pattern data generation unit 138, a concealment data generation unit 139, a YMC data generation unit 141, a storage unit 142, a print An image data generation unit 143.

  The print data analysis unit 134 analyzes the print data given from the communication unit 132, and generates the drawing information of the object included in the print data in the dot pattern data generation unit 138 and the YMC data generation unit 141. Give the necessary data. As illustrated in FIG. 3, the print data analysis unit 134 includes a determination unit 135, a dot pattern determination unit 136, and an object determination unit 137.

  The determination unit 135 sequentially selects objects included in the print data and determines the type of the selected object. Then, the determination unit 135 causes the dot pattern determination unit 136 to perform processing when the selected object is a dot pattern object, and when the selected object is other than a dot pattern object, The determination unit 137 performs processing.

  In response to an instruction from the determination unit 135, the dot pattern determination unit 136 extracts data corresponding to the object (dot pattern object) selected by the determination unit 135 from the print data, and uses the extracted data as dot data. This is given to the pattern data generation unit 138.

  In response to an instruction from the determination unit 135, the object determination unit 137 generates YMC data corresponding to an object (text object, graphic object, or picture object) selected by the determination unit 135 from the print data. Part 141.

The dot pattern data generation unit 138 analyzes the data given from the dot pattern determination unit 136 and generates drawing information necessary for drawing the dot pattern image. Then, the dot pattern data generation unit 138 stores the generated drawing information in the display list stored in the storage unit 142. Here, the display list is a data table for storing drawing information including intermediate codes for performing rasterization according to print data described in PDL.
FIG. 4 is a schematic diagram of a dot pattern image DOPI (DOt Pattern Image). As shown in FIG. 4, the dot pattern image DOPI in the present embodiment is a pattern image formed by dots having a diameter X of about 50 to 100 μm. In the dot pattern image DOPI, for example, character information or the like can be read by a combination of arranged dots. Note that the alternate long and short dash line shown in FIG. 4 is an auxiliary line for specifying dots arranged at lattice points, and is not actually included in the dot pattern image DOPI.

Returning to the description of FIG. 3, the concealment data generation unit 139 specifies the usage level of the toner used for the concealment image printed on the dot pattern image based on the display list stored in the storage unit 142. .
For example, the hidden data generation unit 139 includes an image toner amount level storage unit 140. Then, the concealment data generation unit 139 specifies the toner usage level of the concealment image based on the image toner amount level information stored in the image toner amount level storage unit 140.
FIG. 5 is a schematic diagram showing the image toner amount level information 171. The image toner amount level information 171 is information in a table format that specifies the toner amount level for each type of image.
As shown, the image toner amount level information 171 includes a type column 171a and a toner amount level information column 171b.
The type column 171a stores the type of image. The type of image is classified from the type of object corresponding to the image and the attribute information of the image.
The toner amount level column 171b stores a toner amount level for specifying the toner usage level.
In the present embodiment, the concealment data generation unit 139 specifies, for each dot pattern image, the toner amount level corresponding to the type of image printed on the dot pattern image in the toner amount level information 171. Then, the concealment data generation unit 139 sets the specified toner amount level as the toner use level in the concealment image printed over the dot pattern image.

For example, as in the record R1 shown in FIG. 5, if the type of the object corresponding to the image is text and the character size of the image is larger than a prescribed size, the amount of toner when printing the hidden image Even if there is little, it is thought that it is not difficult to see a character by a dot pattern. For this reason, in the record R1, there is no problem even if the amount of toner used is extremely small. Therefore, in the record R1, the toner amount level is “1” which is the smallest. In addition, when a plurality of sizes of characters are used in the image, it is determined based on the size of the smallest character used.
If the object type corresponding to the image is text as in the record R2, and the character size of the image is smaller than the prescribed size, if the amount of toner when printing the concealed image is extremely small, the character is displayed by the dot pattern. It may be difficult to see. For this reason, it is desirable to slightly increase the amount of toner used in the record R2. Therefore, in the record R2, the toner amount level is “2”, which is the second smallest after the record R1.
If the type of the object corresponding to the image is graphic as in the record R3 and the thickness of the line included in the image is thicker than the specified thickness, even if the amount of toner when printing the hidden image is small, the dot It is considered that the line will not be difficult to see due to the pattern. For this reason, in the record R3, there is no problem even if the amount of toner used is slightly reduced. For example, in the present embodiment, in the record R3, the toner amount level is “2” as in the record R2.
As in the record R4, when the type of the object corresponding to the image is graphic and the line thickness of the image is thinner than the specified thickness, if the amount of toner for printing the concealed image is small, the line is printed by the dot code. It will be difficult to see. For this reason, in the record R4, it is necessary to slightly increase the amount of toner to be used. Therefore, in the record R4, the toner amount level is “3” which is larger than that in the record R3.
If the object type corresponding to the image is a picture, such as the record R5, it is a photograph or the like, so if the amount of toner when printing the concealed image is small, the photograph or the like will appear dull due to the dot pattern. Therefore, the amount of toner used is increased. Therefore, in the record R5, the toner amount level is “4” which is the largest.
In this embodiment, for example, when the toner amount level is “4”, printing is performed with the same toner amount as that used in normal printing, and the toner amount level is small. As the amount of toner increases, the amount of toner used is reduced, but the present invention is not limited to such an example.

Returning to the description of FIG. 3, the concealment data generation unit 139 generates concealment image drawing information to be printed over the dot pattern image based on the display list stored in the storage unit 142 and displays the display information. Process to store in the list.
Further, the concealment data generation unit 139 generates print density information that is control information necessary for adjusting the print density of the concealed image according to the toner usage level of the concealed image determined as described above. To do.

  The YMC data generation unit 141 analyzes the data given from the object determination unit 137 and generates drawing information necessary for drawing the display image. Then, the YMC data generation unit 141 stores the generated drawing information in the display list stored in the storage unit 142.

  The storage unit 142 stores a display list, print density information, and print image data generated by the print image data generation unit 143 from the display list.

The print image data generation unit 143 generates print image data by performing rasterization according to the drawing information stored in the display list stored in the storage unit 142. Then, the print image data generation unit 143 causes the storage unit 142 to store the generated print image data.
FIG. 6 is a schematic diagram of the print image data 172. The print image data 172 includes dot pattern image data 172a, hidden image data 172b, Y image data 172c, M image data 172d, and C image data 172e. Here, the Y image data 172c is image data of a Y image formed with a yellow component of the display image. The M image data 172d is image data of an M image formed with a magenta component of the display image. The C image data 172e is image data of a C image formed with a cyan component in the display image.

  The control unit 144 comprehensively controls the operation of the printing apparatus 130. For example, the control unit 144 performs processing for providing the print image data and print density information generated by the print image data generation unit 133 to the printing unit 145 to form an image.

  The printing unit 145 forms an image on the medium based on the print image data and the print density information given from the control unit 144. As illustrated in FIG. 3, the printing unit 145 includes a development control unit 146, a K development unit 147, a W development unit 148, a Y development unit 149, an M development unit 150, and a C development unit 151.

  The development control unit 146 comprehensively controls each of the K development unit 147, the W development unit 148, the Y development unit 149, the M development unit 150, and the C development unit 151 based on the control of the control unit 144.

The K developing unit 147 is a dot pattern image developing unit that forms a dot pattern image based on the dot pattern image data 172a included in the print image data 172 shown in FIG. In this embodiment, the dot pattern is printed with black toner. However, the present invention is not limited to such a color toner.
The W developing unit 148 is a hidden image developing unit that forms a hidden image based on the hidden image data 172 b included in the print image data 172. In this embodiment, the concealed image is printed with white toner. However, the present invention is not limited to such a color toner. Note that the development control unit 146 controls the W development unit 148 so that the print density indicated by the print density information is obtained when the hidden image is printed.

The Y developing unit 149 is a yellow image developing unit that forms a yellow image based on the Y image data 172 c included in the print image data 172.
The M developing unit 150 is a magenta image developing unit that forms a magenta image based on the M image data 172d included in the print image data 172.
The C developing unit 151 is a cyan image developing unit that forms a cyan image based on the C image data 172e included in the print image data 172.
The Y developing unit 149, the M developing unit 150, and the C developing unit 151 are color image developing units that develop color images, and are also display image developing units that develop display images that the user intends to display. is there.

  FIG. 7 is a schematic configuration diagram illustrating an example of the configuration of the printing unit 145. Each developing unit has the same configuration except for the difference in image color to be formed. Therefore, here, the configuration will be described using the K developing unit 147.

The K developing unit 147 includes a photosensitive drum 147a, a charging roller 147b, an LED (Light Emitting Diode) head 147c, a toner container 147d, a toner supply roller 147e, and a developing roller 147f.
The photosensitive drum 147a is an image carrier that forms an electrostatic latent image on the surface and forms a toner image by attaching toner to the electrostatic latent image.
The charging roller 147b charges the photosensitive drum 147a.
The LED head 147c is an exposure unit that exposes the surface of the photosensitive drum 147a by irradiating light corresponding to a print image to form an electrostatic latent image.
The toner container 147d stores black K toner.
The toner supply roller 147e conveys the K toner stored in the toner container 147d to the developing roller 147f.
The developing roller 147f forms a toner image by attaching toner to the photosensitive drum 147a.

The toner container 148d of the W developing unit 148, the toner container 149d of the Y developing unit 149, the toner container 150d of the M developing unit 150, and the toner container 151d of the C developing unit 151 are respectively white. W toner, yellow Y toner, magenta M toner, and cyan C toner are accommodated.
Here, in the present embodiment, the K toner is a black pigment, and carbon black having a property of absorbing near infrared light is used. On the other hand, pigments having the property of transmitting near infrared light are used for the W toner, Y toner, M toner, and C toner.

The printing unit 145 includes paper feed rollers 181A and 181B, a transfer belt 182, transfer rollers 183A, 183B, 183C, 183D, and 183E, fixing devices 184A and 184B, and paper discharge rollers 185A and 185B.
The paper feed rollers 181A and 181B feed the medium 180 from a medium supply unit (not shown).
The transfer belt 182 conveys the fed medium 180.
The transfer rollers 183A, 183B, 183C, 183D, and 183E are provided to face the photosensitive drums of the developing units, and transfer the toner images formed by the developing units to the medium 180.
The fixing devices 184A and 184B fix the toner image transferred to the medium 180 to the medium 180 by heating and pressing.
The paper discharge rollers 185A and 185B discharge the medium 180 on which the toner image is fixed by the fixing devices 184A and 184B to the outside of the printing apparatus 130.

  The medium 180 fed from the medium supply unit (not shown) via the paper feed rollers 181A and 181B is sequentially transferred with the toner images formed in the developing units in the process of being conveyed by the transfer belt 182. . In the present embodiment, the toner image of the dot pattern image formed by the K developing unit 147, the toner image of the concealed image formed by the W developing unit 148, from the upstream side to the downstream side in the conveyance direction of the medium 180, The yellow image toner image formed by the Y developing unit 149, the magenta toner image formed by the M developing unit 150, and the cyan image toner image formed by the C developing unit 151 are sequentially transferred to the medium 180. The Then, after the toner image formed in each developing unit is transferred to the medium 180, the fixing devices 184A and 184B fix the toner image by applying heat and pressure to the medium 180. The medium 180 on which the toner image is fixed is discharged outside the printing apparatus 130 by the discharge rollers 185A and 185B.

As described above, predetermined information can be read from the medium 180 printed by the printing device 130 by using the reading device 190 as shown in FIG.
The reading device 190 shown in FIG. 8 includes a light emitting unit (not shown) and a light receiving unit.
Then, the light receiving unit reads the reflected light from the medium 180 with respect to the irradiation light with a predetermined wavelength irradiated by the light emitting unit, so that the light receiving unit can read the pattern image printed on the medium 180.
The reading device 190 may be any device that can emit and receive light of a predetermined wavelength. For example, as shown in FIG. 8, the reading device 190 may be a device that emits and receives light with a pen tip as a pen-type device, or may be a flat-bed type scanner or the like. Good. Here, in the present embodiment, the light emitted and received by the reading device 190 is, for example, near infrared light (wavelength: 800 nm to 1000 nm). This near infrared light is absorbed by the carbon black used as the K toner.

(Description of operation)
Next, the processing operation of the image forming system 100 according to the first embodiment will be described.
FIG. 9 is a flowchart illustrating processing performed in the host device 110.
First, when the input unit 116 of the host apparatus 110 receives an input of a print start instruction from the user, the application unit 111, for example, based on the display image and the dot pattern image created by the user via the input unit 116, Is generated (S10). Here, in the present embodiment, it is assumed that the display image includes at least one of a picture, a graphic, and a text. Here, the picture, the graphic, and the text are the types of data of the display image. Then, the application unit 111 gives the generated spool file to the driver unit 112. The spool file is intermediate data for generating print data.

  Next, when a spool file is given from the application unit 111, the PDL data generation unit 113 of the driver unit 112 generates an object corresponding to the type of data included in the display image based on the spool file (S11). . Further, the PDL data generation unit 113 generates a dot pattern image object based on the spool file (S12).

  Further, the PDL data generation unit 113 generates print job data including a type of each object and attributes such as arrangement in a program language for instructing the printing apparatus 130 to perform drawing. Print data including the objects generated in steps S11 and S12 is generated (S13). Here, the type of the object of the dot pattern image generated in step S12 is specific to the object of the dot pattern image different from the picture, graphic, and text. In addition, the arrangement of each object can specify, for example, the start position and size of each object. Then, the PDL data generation unit 113 gives the generated print data to the data transmission / reception unit 114.

  Next, the data transmitting / receiving unit 114 performs processing for transmitting the print data given from the PDL data generating unit 113 to the printing apparatus 130 via the IF unit 115 (S14).

FIG. 10 is a flowchart illustrating processing performed by the print image data generation unit 133 of the printing apparatus 130.
The print data generated and transmitted by the host device 110 is received by the IF unit 131 of the printing device 130. The received print data is given from the communication unit 132 to the print image data generation unit 133 in accordance with an instruction from the control unit 144.
Then, in the print image data generation unit 133, the determination unit 135 of the print data analysis unit 134 acquires the print data given from the communication unit 132 (S20).

  The determination unit 135 analyzes the acquired print data, selects one object for which drawing information has not been generated, and refers to the print job data to determine the type of the selected object (S21). ). When the selected object is a dot pattern, the determination unit 135 proceeds to the process of step S22. If the selected object is text, the determination unit 135 proceeds to the process of step S24. If the selected object is a graphic, the determination unit 135 proceeds to the process of step S26. If the selected object is a picture, the determination unit 135 proceeds to the process of step S28.

In step S <b> 22, the dot pattern determination unit 136 extracts data of a portion corresponding to the selected object (dot pattern) from the received print data, and provides the extracted data to the dot pattern data generation unit 138. . Then, the dot pattern data generation unit 138 calculates a dot pattern print area in which a dot pattern image generated from the selected object is printed based on the data given from the dot pattern determination unit 136. The dot pattern print area is indicated by, for example, the coordinates of the X axis and the Y axis of the medium 180 to be printed.
Next, the dot pattern data generation unit 138 generates drawing information necessary for drawing the selected object (dot pattern) based on the data given from the dot pattern determination unit 136, and this drawing information Is stored in the display list stored in the storage unit 142 (S23). The drawing information includes dot pattern print area information indicating the print area calculated in step S22 and attribute information including type information indicating that the selected object is a dot pattern. To do.

In step S24, the object determination unit 137 extracts data of a portion corresponding to the selected object (text) from the received print data, and provides the extracted data to the YMC data generation unit 141. Then, the YMC data generation unit 141 calculates a text print area in which a text image generated from the selected object is printed based on the data given from the object determination unit 137. The text print area is indicated by the coordinates of the X axis and the Y axis of the medium 180 to be printed, for example.
Next, the YMC data generation unit 141 generates drawing information necessary for drawing the selected object (text) based on the data given from the object determination unit 137, and stores the drawing information in the storage unit. The data is stored in the display list stored in 142 (S25). The drawing information includes the text print area information indicating the print area calculated in step S24, the type information indicating that the selected object is text, and the font size of the text included in the selected object. And attribute information to be indicated.

In step S <b> 26, the object determination unit 137 extracts data of a part corresponding to the selected object (graphic) from the received print data, and provides the extracted data to the YMC data generation unit 141. Then, the YMC data generation unit 141 calculates a graphic print area in which a graphic image generated from the selected object is printed based on the data given from the object determination unit 137. The graphic print area is indicated by the coordinates of the X axis and the Y axis of the medium 180 to be printed, for example.
Next, the YMC data generation unit 141 generates drawing information necessary for drawing the selected object (graphic) based on the data given from the object determination unit 137, and stores the drawing information in the storage unit. The data is stored in the display list stored in 142 (S27). The drawing information includes the graphic print area information indicating the print area calculated in step S26, the type information indicating that the selected object is a graphic, and the thickness of the line included in the selected object. And attribute information to be included.

In step S28, the object determination unit 137 extracts data of a portion corresponding to the selected object (picture) from the received print data, and provides the extracted data to the YMC data generation unit 141. Then, the YMC data generation unit 141 calculates a picture print area in which a picture image generated from the selected object is printed based on the data given from the object determination unit 137. The picture print area is indicated by the coordinates of the X axis and the Y axis of the medium 180 to be printed, for example.
Next, the YMC data generation unit 141 generates drawing information necessary for drawing the selected object (picture) based on the data given from the object determination unit 137, and stores the drawing information in the storage unit. The data is stored in the display list stored in 142 (S29). The drawing information includes picture print area information indicating the print area calculated in step S28 and attribute information including type information indicating that the selected object is a picture.

  Next, the determination unit 135 determines whether drawing information has been generated for all the objects included in the print data (S30). If the drawing information is generated for all objects included in the print data, in other words, if there is no object for which drawing information has not been generated (S30: Yes), the determination unit 135 performs step The process proceeds to S31. On the other hand, when the drawing information is not generated for all the objects included in the print data, in other words, when there is an object for which no drawing information is generated (S30: No), the determination unit 135 The process returns to step S21.

  In step S <b> 31, the concealment data generation unit 139 acquires one piece of dot pattern area information for which the drawing information of the corresponding concealment image has not been generated, from the display list stored in the storage unit 142.

Next, the concealment data generation unit 139 refers to the display list stored in the storage unit 142 and specifies an image other than the dot pattern to be printed in the area indicated by the acquired dot pattern area information ( S32).
Then, the concealment data generation unit 139 specifies the type of the specified image from the attribute information of the specified image. Further, the concealment data generation unit 139 specifies the image toner amount level corresponding to the specified type from the image toner amount level information 171 stored in the image toner amount level information storage unit 140 (S33). When there are a plurality of images specified in step S32, the concealment data generation unit 139 specifies the highest one among the plurality of toner amount levels specified corresponding to each in step S33.

  Next, the concealment data generation unit 139 generates drawing information necessary for drawing the concealment image in the area indicated by the dot pattern area information acquired in step S31, and stores this drawing information in the storage unit 142. The stored display list is stored (S34). Here, the concealment data generation unit 139 causes the concealment image to be printed with a toner amount corresponding to the toner amount level specified in step S33. For example, in the present embodiment, the concealment data generation unit 139 stores the print density information indicating the print density in the storage unit 142 so that the concealed image is printed darker as the specified toner amount level is higher. Let This print density information specifies the print density of the area for each area where the hidden image is printed (for each corresponding dot pattern area).

  Next, the concealment data generation unit 139 determines whether concealment image drawing information has been generated for all the dot pattern area information included in the display list stored in the storage unit 142 (S35). . When the concealment data generation unit 139 generates concealment image drawing information for all dot pattern area information, in other words, when there is no dot pattern area information for which no concealment image drawing information has been generated ( In S35: Yes, the process proceeds to step S36. On the other hand, when the concealment data generation unit 139 has not generated concealed image drawing information for all dot pattern area information, in other words, there is dot pattern area information for which corresponding concealed image drawing information has not been generated. If yes (S35: No), the process returns to step S31.

  In step S36, the print image data generation unit 143 performs rasterization according to the drawing information stored in the display list stored in the storage unit 142, thereby generating the print image data 172 as illustrated in FIG. Generate. For example, the print image data generation unit 143 generates the dot pattern image data 172a in accordance with the dot pattern drawing information. The print image data generation unit 143 generates the hidden image data 172b according to the drawing information of the hidden image. The print image data generation unit 143 generates Y image data 172c, M image data 172d, and C image data 172e in accordance with text, graphic, and picture drawing information. Note that the print image data generation unit 143 causes the storage unit 142 to store the print image data 172 generated in this way.

As described above, the print image data 172 is stored in the storage unit 142. Then, the control unit 144 gives an image formation instruction to the development control unit 146 in accordance with each image data and print density information stored in the print image data 172 stored in the storage unit 142.
Upon receiving such an instruction, the development control unit 146 receives the dot pattern image at the K development unit 147, the hidden image at the W development unit 148, the Y image at the Y development unit 149, and the M image at the M development unit. At 150, the K developing unit 147, the W developing unit 148, the Y developing unit 149, the M developing unit 150, and the C developing unit 151 are controlled so that the C image is formed by the C developing unit 151. The development control unit 146 performs print density control on the W development unit 148 in accordance with print density information provided from the control unit 144.

  Next, with reference to FIG. 7, an operation when an image is formed by the printing apparatus 130 based on the print image data 172 will be described.

Upon receiving a print start instruction from the control unit 144, the development control unit 146 controls a high voltage power source (not shown) to apply a negative voltage to the charging roller 147b in the K development unit 147, and the photosensitive drum 147a. The surface of is negatively charged.
The development control unit 146 controls the LED head 147c to irradiate the surface of the photosensitive drum 147a with light based on the dot pattern image data.
The photosensitive drum 147a receives light emitted from the LED head 147c while rotating. As a result, in the photosensitive drum 147a, the negative charge amount in the portion that receives light, that is, the portion where the dot pattern image is formed is reduced, and an electrostatic latent image is formed.

  The K toner stored in the toner container 147d of the K developing unit 147 is given a negative charge in the process of being conveyed to the photosensitive drum 147a by the toner supply roller 147e and the developing roller 147f. It adheres only to the portion of the surface of 147a where the negative charge amount is reduced.

  Simultaneously with the above operation, the control unit 144 issues a print start instruction to a paper feed / conveyance control unit, a roller drive control unit, and the like (not shown), and causes the medium 180 to be conveyed to the printing unit 145. When the medium 180 conveyed by the paper feed rollers 181A and 181B reaches the K developing unit 147, an electric field generated by a positive voltage applied to a transfer roller 183A provided in the transfer belt 182 from a high voltage power source (not shown). As a result, the dot pattern image formed with the K toner is transferred from the surface of the photosensitive drum 147a to the medium 180.

Subsequently, based on the concealment image data, Y image data, M image data, and C image data, the development control unit 146 performs W toner in the W development unit 148, Y toner in the Y development unit 149, and in the M development unit 150. Each toner image using C toner in the M toner and C developing unit 151 is formed on the surface of the photoconductive drums 148 a, 149 a, 150 a, 151 a, and is sequentially transferred to the medium 180 conveyed by the transfer belt 182. At this time, the development control unit 146 controls the irradiation intensity of the LED head 148c in the W development unit 148 in accordance with the print density indicated by the print density information, thereby reducing the amount of toner attached to the photosensitive drum 148a. Control. For the W toner, Y toner, M toner, and C toner, pigments that transmit light of a predetermined wavelength (in the present embodiment, near infrared light) are used.
A toner image is fixed to the medium 180 conveyed in the direction of the arrow in FIG. 7 by the transfer belt 182 by applying heat and pressure by the fixing devices 184A and 184B. Then, the medium 180 on which the toner image is fixed is discharged to the outside of the printing apparatus 130 by the discharge rollers 185A and 185B, and the image forming operation is completed.

  An example of the toner layer formed on the medium 180 as described above is shown in FIG. FIG. 11 is a longitudinal sectional view showing an example of the toner layer formed on the medium 180. As shown in the figure, since the concealed image 187 is formed with W toner in the W developing unit 148 so as to cover the dot pattern image 186 formed with K toner in the K developing unit 147 on the medium 180, the dot code Can be concealed. On the concealed image 187 formed of W toner, a YMC image 188 as a display image is formed with each toner by the Y developing unit 149, the M developing unit 150, and the C developing unit 151. At this time, the thickness Y of the hidden image 187 formed by the W developing unit 148 changes according to the YMC image 188, and the amount of toner used is adjusted. For example, in a portion where the YMC image 188 is a text image or the like, it is considered that the image can be recognized without reliably hiding the dot pattern, so that the amount of toner used is slightly less (thickness Y is less Thin). On the other hand, if the YMC image 188 is a photograph or the like, and the YMC image 188 is a graphic image or the like including a thin line or a small point, a fine print result can be obtained unless the dot pattern is surely hidden. Therefore, the amount of toner used is slightly larger (thickness Y is thicker).

  As described above, according to the first embodiment, in order to control the amount of toner when printing a hidden image according to the type of object of the normal image printed over each dot pattern image, Consumption of the amount of toner used when printing a concealed image can be suppressed.

Embodiment 2. FIG.
Next, a second embodiment will be described. In the first embodiment, the amount of toner used for the hidden image is adjusted by the type of object corresponding to the image printed over the dot pattern. However, the amount of toner used for the hidden image is lower than that of the related art. As a result, a portion where the concealed image becomes smaller (the concealed image becomes thinner) occurs.
In addition to concealing the dot pattern and improving the print quality of the display image, the effect of printing the concealed image on the dot pattern is to protect the dot pattern by covering the dot pattern with the concealed image. There is also an effect. For example, when the reader 190 (see FIG. 8) frequently touches the dot pattern, the dot pattern may be peeled off when the reader 190 touches the dot pattern. It is possible to prevent the pattern from peeling off. In particular, when the area where the dot pattern is printed is narrow, there is a problem that the dot pattern is likely to be peeled off because the portions in contact with the reading device 190 are concentrated. In this regard, when the area where the dot pattern is printed is large, it is considered that the reader 190 is brought into contact with the dot pattern area evenly in order to read as much as possible as a human psychology. It is thought that there is little peeling off.
For this reason, in the second embodiment, in addition to the type of object corresponding to the image printed over the dot pattern image, the toner amount used for the concealed image that fills the dot pattern is determined by the area of the dot pattern image. adjust.

(Description of configuration)
As illustrated in FIG. 1, the printing system 200 according to the second embodiment includes a host device 110 and a printing device 230. The printing system 200 according to the second embodiment is different from the printing system 100 according to the first embodiment in a printing apparatus 230.

  FIG. 12 is a block diagram schematically showing the configuration of the printing apparatus 230 according to the second embodiment. The printing apparatus 230 includes an IF unit 131, a communication unit 132, a print image data generation unit 233, a control unit 144, and a printing unit 145. The printing apparatus 230 according to the second embodiment is different from the printing apparatus 130 according to the first embodiment in a print image data generation unit 233.

  The print image data generation unit 233 includes a print data analysis unit 134, a dot pattern data generation unit 138, a concealment data generation unit 239, a YMC data generation unit 141, a storage unit 142, and a print image data generation unit 143. Prepare. The print image data generation unit 233 according to the second embodiment is different from the print image data generation unit 133 according to the first embodiment in the concealment data generation unit 239.

  Based on the display list stored in the storage unit 142, the concealment data generation unit 239 specifies the toner usage level of the concealment image printed over the dot pattern image. In the first embodiment, the concealment data generation unit 139 specifies the usage level of the toner used for the concealment image based on the image toner amount level information 171 stored in the image toner amount level storage unit 140. In the second embodiment, based on the area toner amount level information stored in the area toner amount level storage unit 252, the usage level of the toner used for the hidden image is specified.

FIG. 13 is a schematic diagram showing area toner amount level information 273. The area toner amount level information 273 is information in a table format for specifying the toner amount level for each area of the dot pattern image.
As illustrated, the area toner amount level information 273 includes an area column 273a and a toner amount level information column 273b.
The area column 273a stores the area range of the dot pattern image.
The toner amount level column 273b stores a toner amount level for specifying the toner usage level.

For example, as shown in the record R21 of FIG. 13, when the area of the dot pattern image is 5 square centimeters or more, the reading device 190 can be applied over a wide range, and thus the dot pattern is protected with a concealed image. There is no need to do so. Therefore, in the record R21, the toner amount level is “0”.
As in the record R22, when the area of the dot pattern image is less than 5 square centimeters to 3 square centimeters or more, the reading device 190 is applied to a range determined to some extent. For this reason, since it is considered that there is a certain need to protect the dot pattern, the toner amount level is set to “1” which is the lowest level.
When the area of the dot pattern image is less than 3 square centimeters to 1.5 square centimeters or more as in the record R23, the reading device 190 is applied to a range determined more than in the case of the record R22. Therefore, since it is considered that the necessity of protecting the dot pattern is higher than in the case of the record R22, the toner amount level is set to “2” which is higher than that in the case of the record R22.
When the area of the dot pattern image is less than 1.5 square cm as in the record R24, the reading device 190 is frequently applied to a narrow range. Therefore, since the necessity of protecting the dot pattern is the highest, the toner amount level is set to “3”, which is the highest.

  Then, the concealment data generation unit 239 specifies, from the image toner amount level information 171, the toner amount level corresponding to the type of image to be printed over the range including the dot pattern image for each dot pattern image. Further, the concealment data generation unit 239 specifies the toner amount level corresponding to the area of the dot pattern image from the area toner amount level information 273 for each dot pattern image. Then, the hidden image data generation unit 239 adds the toner amount level specified from the image toner amount level information and the toner amount level specified from the area toner amount level information 273 to overlap the dot pattern image. The toner usage level in the concealed image to be printed is specified.

  Returning to the description of FIG. 12, the concealment data generation unit 239 generates concealment image drawing information to be printed over the dot pattern image based on the display list stored in the storage unit 142. Process to store in. Further, the concealment data generation unit 239 generates print density information that is control information necessary for adjusting the density of the concealed image according to the toner amount level of the concealed image determined as described above.

  FIG. 14 is a flowchart illustrating processing performed by the print image data generation unit 233 of the printing apparatus 230. The processes in steps S20 to S33, S35, and S36 shown in FIG. 14 are the same as the processes in the steps indicated by the same reference numerals in FIG.

  In step S33, the concealment data generation unit 239 specifies the image toner amount level from the image toner amount level information 171 stored in the image toner amount level information storage unit 140, and then proceeds to the process of step S40.

  In step S40, the concealment data generation unit 239 calculates the area of the extracted dot pattern print area. Then, the concealment data generation unit 239 specifies the toner amount level corresponding to the calculated area from the area toner amount level information 273 stored in the area toner amount level storage unit 252.

  Next, the concealment data generation unit 239 calculates a final toner amount level by using the toner amount level specified in step S33 and the toner amount level specified in step S40 (S41). For example, the concealment data generation unit 239 calculates the toner usage level by adding the toner amount level specified in step S33 and the toner amount level specified in step S40. Here, the toner amount level specified in step S33 and the toner amount level specified in step S40 are added. However, the present invention is not limited to such an example, and is specified in step S33. When the toner amount level is constant, the larger the toner amount level specified in step S40, the higher the toner usage level, and the toner amount level specified in step S40 is constant. The toner usage level may be determined in any way as long as the toner usage level increases as the toner amount level specified in step S33 increases.

Next, the concealment data generation unit 239 generates drawing information necessary for drawing the concealment image in the area indicated by the dot pattern area information acquired in step S31, and stores this drawing information in the storage unit 142. The stored display list is stored (S42). Here, the concealment data generation unit 239 causes the concealment image to be printed with a toner amount corresponding to the toner usage level calculated in step S41. For example, also in the present embodiment, the concealment data generation unit 239 causes the storage unit 142 to store print density information indicating the print density so that the concealed image is printed darker as the calculated use level is higher.
Then, the hidden data generation unit 239 proceeds to the process of step S35.

  As described above, according to the second embodiment, where the area of each dot pattern image is large, the amount of toner used for the corresponding concealment image is reduced, whereas where the area is small, By increasing the amount of toner used for the corresponding hidden image, it is possible to prevent the dot pattern image from peeling off while suppressing consumption of the toner amount used for the hidden image.

  In the first and second embodiments described above, the concealment data generation units 139 and 239 generate print density information indicating the print density of the concealed image, thereby controlling the amount of toner used in the concealed image. However, it is not limited to such control. For example, when the concealment data generation units 139 and 239 generate concealment image drawing information, it is also possible to control the amount of toner used by changing the pattern of the concealment image to be printed. For example, the amount of toner used can be controlled by increasing or decreasing the number of pixels printed using toner among the pixels included in the area where the hidden image is printed. As an example, as shown in FIG. 5, when the toner amount level is “1” to “4”, the toner amount among the four pixels adjacent in the vertical and horizontal directions included in the area where the concealed image is printed. When the level is “1”, white printing is performed on one pixel, and when the toner amount level is “2”, white printing is performed on two pixels. When “3”, white printing is performed on three pixels, and when the toner amount level is “4”, the pattern of the concealed image is configured so that white printing is performed on four pixels. By forming, printing can be performed with the amount of toner used corresponding to each toner amount level.

  In the first and second embodiments described above, the concealment image is printed in the area indicated by the dot pattern area information. In other words, the area where the dot pattern is printed matches the area where the concealment image is printed. Although configured as described above, these areas do not necessarily coincide with each other.

  In the first and second embodiments described above, the type of the image is specified based on the type of the object corresponding to the image and the attribute information of the image such as the font of the character or the thickness of the line. However, the present invention is not limited to such an example. For example, the type of image may be specified only from the type of object corresponding to the image. In other words, the image types need only be classified according to the desired print quality.

  In the first and second embodiments described above, the embodiments in which the present invention is applied to the electrophotographic printing apparatuses 230 and 230 have been described. However, the present invention is not limited to these embodiments. For example, the present invention can be applied to an ink jet type or thermal transfer type printing apparatus (image forming apparatus). The present invention is also applicable to a copying machine, a facsimile machine, a multifunction machine, and the like.

  100, 200: printing system, 110: host device, 111: application unit, 112: driver unit, 115: IF unit, 116: input unit, 130, 230: printing device, 131: IF unit, 132: communication unit, 133 , 233: Print image data generation unit, 134: Print data analysis unit, 135: Determination unit, 136: Dot pattern determination unit, 137: Object determination unit, 138: Dot pattern data generation unit, 139, 239: Concealment data generation unit 140: Image toner amount level storage unit, 141: YMC data generation unit, 142: Storage unit, 143: Print image data generation unit, 144: Control unit, 145: Printing unit, 146: Development control unit, 147: K development , 148: W developing unit, 149: Y developing unit, 150: M developing unit, 1 1: C developing unit, 252: area toner amount level storage unit.

Claims (12)

First image data for printing the first image based on print data including a first image and a second image printed over at least a part of the first image; Print image data generation for generating print image data including a cover image for printing a cover image to be printed over the first image, and a second image data for printing the second image And
A printing unit that performs printing based on the print image data,
The print image data generation unit specifies a use level of a colorant when printing the concealed image according to the type of the second image,
The image forming apparatus, wherein the printing unit prints the hidden image according to the specified usage level. The print image data generation unit specifies a print density of the hidden image according to the specified use level,
The image forming apparatus according to claim 1, wherein the printing unit prints the concealed image according to the specified print density. The image forming apparatus according to claim 1, wherein the print image data generation unit changes a pattern of the concealed image according to the specified usage level. The second image is composed of one or more objects,
4. The image forming apparatus according to claim 1, wherein the type of the second image is specified by using a type of an object that overlaps the first image. 5. The image forming apparatus according to claim 4, wherein the object type includes at least one of a text, a graphic, and a picture. The first image is composed of one or more objects,
The concealment image is printed by overlapping each object constituting the first image,
The type of the second image is specified for each object constituting the first image by using the type of the object constituting the second image that overlaps the object included in the first image. And
The print image data generation unit specifies a use level of a colorant for printing the concealed image for each object constituting the first image,
The image forming apparatus according to claim 4, wherein the printing unit prints the concealed image for each object constituting the first image according to the specified usage level. The print image data generation unit identifies the usage level according to a type of the second image and an area on which the first image is printed. The image forming apparatus described in the item. The printing unit prints the first image with a first colorant that can be read by a predetermined reading device, and reads the second image and the concealed image by the predetermined reading device. The image forming apparatus according to claim 1, wherein printing is performed using a second colorant that cannot be performed. The first colorant absorbs light of a predetermined wavelength;
The image forming apparatus according to claim 8, wherein the second colorant transmits light having the predetermined wavelength. The print data includes identification information for identifying the first image,
The image formation according to any one of claims 1 to 9, wherein the print image data generation unit distinguishes the first image from the second image based on the identification information. apparatus. 11. The image according to claim 1, wherein the concealed image is one that protects the first image by being printed over the first image. 11. Forming equipment. First image data for printing the first image based on print data including a first image and a second image printed over at least a part of the first image; Print image data generation for generating print image data including a cover image for printing a cover image to be printed over the first image, and a second image data for printing the second image Process,
A printing process for performing printing based on the print image data,
The print image data generation process is a process of specifying a use level of a colorant when printing the concealment image according to the type of the second image,
The image forming method, wherein the printing process is a process of printing the concealed image in accordance with the specified usage level.

Images