JP2008016888A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus and an image forming method capable of adding optimum information and printing the added information, even if specific attributes exist on the printing surface of a recording sheet. <P>SOLUTION: The apparatus is provided with an attribute reading means 106, arranged on a carrying path for carrying a recording sheet pulled out from sheet feeder means 101, 105 and is used for reading the attributes of the printing surface of the recording sheet; an information-adding means 102 for adding information to the printing surface of the recording sheet; and a control means 110 for changing the setting, in adding the information by the information-adding means 102, when the specific attributes are read from the printing surface of the recording sheet by the attribute reading means 106. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and an image forming method used for an electrophotographic copying machine, a printer, an MFP (Multi Function Peripherals) which is a multifunction machine, and the like.

  2. Description of the Related Art Conventionally, some image forming apparatuses can add information such as copy restraint information and invisible information such as background patterns and security codes in addition to image information such as characters, photographs, and figures.

  For example, depending on the type of paper such as banknotes, it is determined whether to add an abuse prevention pattern to the output image, and if it is determined to add, a technique for adding an abuse prevention pattern to the image Is disclosed (Patent Document 1).

Also known is a technique for preventing unauthorized leakage of confidential information by inputting digital additional information for identifying a document and printing out a document in which the additional information is embedded in an image portion (Patent Document 2). .
Japanese Patent No. 3033497 JP-A-6-22119

  By the way, in the case of the above-described electrophotographic printer or MFP, the attributes of the printing surface of the recording paper set in the paper feeding cassette or paper feeding tray (characteristics of the recording paper itself, or security information added to the recording paper) Etc.), certain attributes may already exist.

  However, none of the conventional techniques considers whether or not a specific attribute already exists on the printing surface. Under the image forming conditions optimized that the specific attribute does not exist, Information such as a security code was added. For this reason, if a specific attribute already exists on the print surface, even if a copy-forgery-inhibited pattern or security code is added, the added information cannot be read due to the specific attribute existing on the print surface. The printed result may not be obtained.

  The present invention has been made in view of the above circumstances, and can form an image that can be printed with optimum information added even when a specific attribute already exists on the printing surface of the recording paper. An object is to provide an apparatus and an image forming method.

The above problem is solved by the following means.
(1) An attribute reading unit that is arranged on a transport path for transporting the recording paper drawn from the paper feeding unit and reads the attribute of the printing surface of the recording paper, and an information addition for adding information to the printing surface of the recording paper And a control means for changing a setting for adding information by the information adding means when a specific attribute is read from the printing surface of the recording paper by the attribute reading means. An image forming apparatus.
(2) The image forming apparatus according to item 1 above, wherein the specific attribute is a characteristic of the printing surface of the recording paper such as reflection density, hue, and saturation of the printing surface of the recording paper.
(3) The image forming apparatus according to item (1), wherein the specific attribute is information already added to a printing surface of a recording sheet.
(4) The image forming apparatus according to any one of items 1 to 3, wherein the attribute reading unit includes at least one light receiving element having spectral sensitivity suitable for reading an attribute of a printing surface of a recording sheet.
(5) The image forming apparatus according to any one of (1) to (4), wherein the attribute reading unit is arranged on the upstream side of the image forming process unit on the transport path.
(6) The reading units 1 to 5 described above are arranged at a plurality of locations in the width direction of the recording paper, or arranged so as to be detectable with a length in the longitudinal direction over the width direction of the recording paper. The image forming apparatus according to any one of the above.
(7) a step of reading an attribute of a printing surface of the recording paper on a conveyance path for conveying the recording paper pulled out from the paper supply means, a step of adding information to the printing surface of the recording paper, and the read recording paper And a step of changing a setting when adding the information when a specific attribute is read from the printing surface.

  According to the invention described in (1) above, when the recording paper pulled out from the paper feeding means is transported along the transport path, a specific attribute, such as the density of the recording paper, is recorded on the printing surface of the recording paper. If there is security information or the like, the attribute is read by attribute reading means arranged in the transport path. Information is added to the printing surface of the recording paper, but the setting for adding information to the recording paper is changed based on the read attribute. Therefore, even when a specific attribute already exists on the printing surface of the recording paper, it is possible to appropriately add desired information without being influenced by the existing attribute.

  According to the invention described in item (2) above, the setting for adding information is changed based on the characteristics of the printing surface of the recording paper itself, such as the reflection density, hue and saturation of the printing surface of the recording paper.

  According to the invention described in item (3) above, the setting for adding information is changed based on the information already added to the printing surface of the recording paper.

  According to the invention described in item (4) above, the print surface of the recording paper can be accurately read by at least one light receiving element having spectral sensitivity suitable for reading the attribute of the print surface of the recording paper.

  According to the invention described in item (5) above, since the attribute of the printing surface of the recording paper is read before the image forming process by the attribute reading means, information is added to the printing surface with the setting changed securely. be able to.

  According to the invention described in item (6), it is possible to change the formation of the additional information in the width direction based on the attribute in the print surface width direction of the recording paper.

  According to the invention described in item (7), the setting of the additional information for the recording paper is changed based on the specific attribute read from the printing surface of the recording paper. For this reason, even if a specific attribute already exists on the printing surface of the recording paper, a desired image to which security information or the like is added can be output regardless of the existing attribute.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to an embodiment of the present invention.

  In FIG. 1, the image forming apparatus includes a paper feed cassette 101, an imaging unit 102, an intermediate transfer belt 103, a paper feed tray 105 containing recording paper, and a contact type provided on a recording paper transport path. An image sensor 106, a recording paper conveyance guide unit 107, a secondary transfer roller 108, a paper discharge tray 109, and a controller 110 are provided. The imaging unit 102 functions as an image forming unit for forming an image on the printing surface of the recording paper, and also functions as an information adding unit for adding information such as a background pattern and a security code to the printing surface of the recording paper.

  In this image forming apparatus, when a request for printing or copying is received, the recording paper is pulled out from the paper feeding cassette 101 or the paper feeding tray 105 in a predetermined direction (in the direction of the arrow 104) and conveyed along the recording paper conveyance guide unit 107. Is done.

  A contact-type image sensor 106 is disposed on the recording paper conveyance path at a position upstream of the image forming unit, and the image sensor 106 prints the printing surface of the recording paper conveyed on the recording paper conveyance path. It is supposed to be read over the entire width direction.

  The image sensor 106 is small and has a close contact type with less restrictions on installation space or the like, but may be a reduced type image sensor.

  When the contact image sensor 106 reads an attribute from the printing surface of the recording paper, the controller 110 outputs four values Y (yellow), M (magenta), C (cyan), and K (black) according to the read attribute. In the color imaging unit 102, image forming conditions for adding information such as a tint block and security information are changed.

  In the imaging unit 102 for four colors Y, M, C, and K, image information requested to be printed or copied and additional information such as a copy-forgery-inhibited pattern and security information are primarily transferred onto the intermediate transfer belt 103. The secondary transfer roller 108 collectively transfers the recording sheet conveyed along the recording conveyance guide 107.

  The transferred recording paper is conveyed to a fixing unit (not shown) and then discharged to a paper discharge tray 109. Additional information is printed together with the image information on the discharged recording paper.

  The image sensor 106 may be divided into a plurality of parts in the width direction of the recording paper. With such a configuration, it is possible to adjust or change the formation of additional information in the width direction based on the attributes detected from each image sensor in the print surface width direction of the recording paper. Further, the image sensor 106 may not be provided over the entire print surface width direction of the recording paper, and the image sensor 106 having a length for detecting a part of the recording paper in the print surface width direction may be provided.

  As described above, in the image forming apparatus according to this embodiment, the attribute of the printing surface of the recording paper is read by the image sensor 106 arranged on the recording paper transport path, and based on the result, the controller 110 causes the recording paper to be recorded. It is supposed to change the setting at the time of adding information. Here, the attributes of the printing surface of the recording paper may be characteristics of the printing surface of the recording paper itself such as reflection density, hue, and saturation of the recording paper, or already added to the printing surface of the recording paper. It may be information such as security information.

  FIG. 2 is a flowchart showing processing from the start of printing to the start of image formation in the image forming apparatus of FIG.

  In FIG. 2, when a print start request is received in step S201, the print surface attribute is detected by the image sensor 106 in step S202, and the process proceeds to step S203.

  Here, the attribute is, as described above, the characteristics of the printing surface of the recording paper itself (reflection density, hue, saturation, etc.), or information already added to the printing surface of the recording paper (addition of security code etc.) Information).

  In step S203, it is determined whether a specific attribute exists. If the specific attribute does not exist (NO in step S203), the process proceeds to step S206. If the specific attribute exists (YES in step S203), the specific attribute is analyzed in step S204. Next, in step S205, additional information setting change processing is executed for changing the process conditions for creating additional information such as a security code and a background pattern based on the analysis result of the specific attribute.

  Thereafter, image formation is started in step S206.

  FIG. 3 is a flowchart showing a process when a copy-forgery-inhibited pattern is printed as additional information.

  In FIG. 3, when a copy-forgery-inhibited pattern print start request is received in step S301, the print surface attribute is detected by the image sensor 106 in step S302. In step S303, it is determined whether or not a specific attribute exists. to decide. As described above, the specific attribute is a characteristic of the printing surface of the recording paper itself (reflection density, hue, saturation, etc.) or information already added to the printing surface of the recording paper (additional information such as a security code). ).

  If the specific attribute does not exist (NO in step S303), in step S311, the process condition for forming the additional information on the background pattern is set to the default setting for the background pattern, and then image formation is started in step S313. To do.

  If the specific attribute exists (YES in step S303), the attribute is analyzed in step S304.

  In step S305, it is determined based on the analysis result whether a tint block can be added. If the copy-forgery-inhibited pattern can be added (YES in step S305), in step S306, after executing the process of changing the setting for the copy-forgery-inhibited pattern, image formation is started in step S313.

  If the copy-forgery-inhibited pattern cannot be added (NO in step S305), in step S307, the user is informed that “the designated recording paper is not likely to function as a copy-forgery-inhibited pattern even if the copy-forgery-inhibited pattern is printed”. Notice.

  This notification may be displayed on the printer driver screen of the terminal when the image forming apparatus is a printer, and may be displayed on the operation panel or the like when the image forming apparatus is a copying machine.

  Thereafter, in step S308, the user is prompted to determine whether or not to continue printing, and if the user inputs that printing is not to be continued (NO in step S308), print cancel processing is performed in step S309. This process is terminated. Note that the user may be instructed to change the recording paper set in the designated paper feed cassette 101 or to use another paper feed cassette.

  If the user inputs to continue printing (YES in step S308), in step S310, the user is prompted to determine whether or not to give up the background pattern addition, and the user does not input that he / she does not give up the background pattern addition. (NO in step S310), but in step S311, there is a high possibility that the background pattern will not function as a background pattern. However, after setting the process conditions for forming the additional information on the background pattern to the default setting for the background pattern, In step S313, image formation is started.

  If the user inputs an instruction to give up the background pattern addition (YES in step S310), the background pattern addition is stopped in step S312 and image formation other than the background pattern is started in step S313.

  FIG. 4 is a flowchart showing an example of the attribute analysis process (step S304) of FIG.

  The light receiving element of the contact image sensor 106 is composed of three general RGB primary colors. Since the attribute of the printing surface itself of the recording paper is analyzed, a high degree of analysis is not required.

  In FIG. 4, in step S401, the image sensor 106 reads the print surface of the recording paper conveyed from the paper supply cassette 101 or the paper supply tray 105 over the entire width direction of the recording paper, so that the data (R, G, B) is obtained.

  In step S402, the data (R, G, B) is averaged (not shown), and each average value is converted into a color value (L, C, H).

  L is data corresponding to lightness values of 0 to 100, and is 0: black and 100: white. The larger the number, the brighter the data.

  C is data corresponding to a saturation value of 0 to 100, 0: achromatic color, 100: chromatic color, and the larger the number, the brighter the color.

  H is data corresponding to a hue of a value from 0 to 360, which is approximately 0: red, 90: yellow, 180: green, 270: blue, and 0 = 360 because one round is performed at 360 degrees. .

  In step S403, it is determined whether L is less than 80 (L <80). If L <80, that is, if the recording paper density is high (YES in step S403), a background pattern is added in step S404. Even if it is determined that there is a high possibility that it will not function, it is determined that the copy-forgery-inhibited pattern printing is impossible, and then the process returns.

  If L ≧ 80 (NO in step S403), it is determined in step S405 whether C exceeds 30 (C> 30). If C> 30, that is, if the recording paper saturation is high (step S405). If YES in S405), the process proceeds to step S404, and it is highly possible that the function does not function even if a copy-forgery-inhibited pattern is added.

  If C> 30 (NO in step S405), it is determined in step S406 whether C ≦ 5. If C ≦ 5 (YES in step S406), in step S407, the recording paper saturation and recording are determined. Since both the paper densities are low, a decision is made to print the tint block in black and then the process returns. Black printing may be the default setting for the tint block.

  If C ≦ 5 is not satisfied (NO in step S406), then classification is performed based on the hue data H. First, in step S408, it is checked whether or not 0 ≦ H <60. If 0 ≦ H <60 (YES in step S408), a determination is made to print the tint block in red in step S409, and then the return. To do.

  If 0 ≦ H <60 (NO in step S408), it is determined whether or not 60 ≦ H <120 in step S410. If 60 ≦ H <120 (YES in step S410), a tint block is determined in step S411. Is determined to print in yellow, and then returns.

  If 60 ≦ H <120 (NO in step S410), in step S412, it is determined whether 120 ≦ H <200. If 120 ≦ H <200 (YES in step S412), in step S413, After making a decision to print the tint block in green, return.

  If 120 ≦ H <200 (NO in step S412), it is determined in step S414 whether 200 ≦ H <270. If 200 ≦ H <270 (YES in step S414), in step S415, After making a decision to print the tint block in cyan, the process returns.

  If 200 ≦ H <270 (NO in step S414), in step S416, it is determined whether 270 ≦ H <300. If 270 ≦ H <300 (YES in step S416), in step S417, After making a decision to print the tint block in blue, return.

  If 270 ≦ H <300 is not satisfied (NO in step S416), in step S418, a determination is made to print the tint block in magenta, and then the process returns.

  Based on the determination of each print color, the setting is changed in step S306 in FIG.

  FIG. 5 is a flowchart showing another example of the attribute analysis process (step S304) of FIG.

  The light receiving element of the contact image sensor 106 is composed of three general RGB primary colors. Since the attribute of the printing surface itself of the recording paper is analyzed, a high degree of analysis is not required.

  In FIG. 5, in step S501, the image sensor 106 reads the entire print surface of the recording paper conveyed from the paper feed cassette 101 or the paper feed tray 105 in the width direction of the recording paper, and the obtained data (R, G , B) is averaged to obtain brightness data L corresponding to brightness.

  In step S502, classification is performed based on the brightness data L, and it is determined whether L ≧ 95. If L ≧ 95 (YES in step S502), in step S503, “background pattern 0” is set. After making a decision, return.

  Here, the “background pattern 0” is composed of a copy check pattern and a background pattern. When the copy pattern is copied, there are a copy check pattern that is lost (negative) and a positive (positive) pattern with respect to the background pattern. The copy-forgery-inhibited pattern 0 may be set as a default setting.

  If L ≧ 95, that is, if L is less than 95 (NO in step S502), it is determined in step S504 whether 90 ≦ L <95.

  If 90 ≦ L <95 (YES in step S504), in step S505, after determining to set to “background pattern 1”, the process returns.

  The “background pattern 1” has a higher pattern density and dot size than the “background pattern 0”, and the background pattern is darker in the case of negative and the copy check pattern is darker in the case of positive. It is set to be.

  If 90 ≦ L <95 (NO in step S504), it is determined in step S506 whether 85 ≦ L <90 is satisfied. If 85 ≦ L <90 (YES in step S506), step S507 is performed. Then, after determining to set to “background pattern 2”, the process returns.

  The “background pattern 2” has a pattern density or dot size larger than that of the “background pattern 1”, so that the background pattern is negative and the copy suppression pattern is positive. Set to darken.

  If 85 ≦ L <90 is not satisfied (NO in step S506), it is determined in step S508 whether 80 ≦ L <85 is satisfied. If 80 ≦ L <85 (YES in step S508), step S509 is performed. Then, after determining to set to “background pattern 3”, the process returns.

  The “background pattern 3” has a pattern density or dot size larger than that of the “background pattern 2”, so that the background pattern is negative and the copy check pattern is positive. Set to darken.

  If 80 ≦ L <85, specifically, if L <80 (when the paper density is high) (NO in step S508), there is a high possibility that even if a background pattern is added, it does not function in step S510. Therefore, after determining that the background pattern cannot be printed, the process returns.

  Based on the determination of the local pattern, the setting is changed in step S306 in FIG.

  FIG. 6 is a flowchart showing the attribute analysis process (step S304) when additional information such as security information printed on the printing surface of the recording paper already exists.

  The light receiving element of the contact image sensor 106 is composed of three general RGB primary colors. In order to analyze an attribute (for example, security information) already printed on the printing surface of the recording paper, it is necessary to read it with a relatively high resolution.

  In FIG. 6, in step S601, the printing surface of the recording sheet conveyed from the sheet feeding cassette 101 or the sheet feeding tray 105 is read by the image sensor 106 over the entire width direction of the recording sheet, and data (R, G, B) is read. Get.

  In step S602, the data (R, G, B) is converted into color values (L, C, H).

  By paying attention to pixels with relatively high saturation C, attributes (security information) that have already been printed are extracted, and the code information portion is classified based on data H corresponding to the hue.

  In step S603, it is determined whether or not 40 ≦ H <160. If 40 ≦ H <160 (YES in step S603), in step S604, the existing security information includes toner made of yellow color material, and the like. In order to additionally record identifiable security information that is printed with ink, the process returns after making a decision to print with toner or ink made of cyan or magenta color material.

  If 40 ≦ H <160 (NO in step S603), it is determined in step S605 whether 160 ≦ H <280. If 160 ≦ H <280 (YES in step S605), step S606 is performed. The existing security information is printed with toner or ink made of cyan color material, and in order to add additional security information that can be identified, the decision is made to print with toner or ink made of magenta or yellow color material. After going, return.

  If 160 ≦ H <280, specifically, if 280 ≦ H <360 or 0 ≦ H <40 (NO in step S605), in step S607, the existing security information is made of magenta color material. In order to additionally record identifiable security information that has been printed with toner or ink, a decision is made to print with toner or ink made of yellow or cyan color material, and then the process returns.

  Note that various numerical values, threshold values, and the like used in the determination conditions are not limited to the above-described embodiment, and can be changed as appropriate according to the apparatus.

1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. 2 is a flowchart illustrating processing from the start of printing to the start of image formation in the image forming apparatus of FIG. 1. It is a flowchart which shows the process at the time of printing a tint block as additional information. It is a flowchart which shows an example of the attribute analysis process (step S304) of FIG. It is a flowchart which shows the other example of the attribute analysis process (step S304) of FIG. It is a flowchart which shows an example of the attribute analysis process (step S304) when the information already printed on the printing surface of a recording paper exists.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Paper cassette 102 Imaging unit 105 Paper feed tray 106 Image sensor 110 Controller

Claims (7)

An attribute reading unit arranged on a conveyance path for conveying the recording sheet pulled out from the sheet feeding unit and reading an attribute of a printing surface of the recording sheet;
Information adding means for adding information to the printing surface of the recording paper;
A control unit that changes a setting when adding information by the information adding unit when a specific attribute is read from the printing surface of the recording paper by the attribute reading unit;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein the specific attribute is a characteristic of the printing surface of the recording paper itself such as reflection density, hue, and saturation of the printing surface of the recording paper.   The image forming apparatus according to claim 1, wherein the specific attribute is information already added to a print surface of a recording sheet.   The image forming apparatus according to claim 1, wherein the attribute reading unit includes at least one light receiving element having spectral sensitivity suitable for reading an attribute of a printing surface of recording paper.   The image forming apparatus according to claim 1, wherein the attribute reading unit is disposed on the upstream side of the image forming process unit on the transport path.   The image forming apparatus according to claim 1, wherein the reading unit is divided and installed in a plurality in the width direction of the recording paper. Reading the attribute of the printing surface of the recording paper on the transport path for transporting the recording paper drawn from the paper feeding means;
Adding information to the printing surface of the recording paper;
When a specific attribute is read from the printing surface of the read recording paper, a step of changing the setting when adding the information;
An image forming method comprising:

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