JP2007280162A - Image generation device, information reader, print medium, image generation method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent variation of a toner area between media and the occurrence of uneven toner presence in a medium in the case of printing an image obtained by encoding information. <P>SOLUTION: The image generation device includes: an identification information encoding part 31 for encoding document data to be printed on a medium or encoding identification information of the medium itself; a position code generating part 32 for encoding the position information on the medium to generate a position code; a code plane generating part 33 for generating a code plane where the position codes are disposed with a predetermined space in two dimensions, identification codes are disposed adjacent to the position code in two dimensions, and the position code or identification code is converted according to the arrangement position; and a code image generating part 34 for imaging the code plane to generate a code image. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image generation apparatus that generates an image to be printed by an image forming apparatus such as a copying machine or a printer, and more particularly to an image generation apparatus that generates a code image representing predetermined information.

  In recent years, characters and pictures are drawn on special paper on which fine dots are printed, and the data written on the paper by the user is transferred to a personal computer or mobile phone. The technology that makes it possible is drawing attention. In this technique, small dots are printed on this special paper at intervals of, for example, about 0.3 mm, and this is configured to draw all different patterns for each grid of a predetermined size, for example. By reading this using a dedicated pen with a built-in camera, for example, the position of characters etc. written on this special paper can be specified, and such characters etc. can be used as electronic information Is possible.

In addition to the coordinate information used for specifying the position of characters and the like, there is also known a technique for encoding and printing document information printed on paper (see, for example, Patent Documents 1 and 2).
Among these, in Patent Document 1, code symbols are arranged in a matrix on a medium, and the coordinate information and information of a document printed on the medium are encoded in the code symbol.
Also in Patent Document 2, a two-dimensional code pattern is arranged in a matrix, and coordinate information indicating a code position on a paper surface and identification information of a document page printed together with the two-dimensional code pattern are two-dimensional code. Encoded using dots within.

JP 2000-293303 A JP 2004-094907 A

However, the techniques of Patent Documents 1 and 2 have the following problems.
First, in the technique of Patent Document 1, code symbols are periodically printed on a medium. Therefore, when a code symbol is printed using a visible color material, there is a problem that the structure of the code symbol is noticeable and the printed document is very uncomfortable.

  On the other hand, in the technique of Patent Document 2, the area of the two-dimensional code pattern printed on the paper surface is reduced by configuring the two-dimensional code pattern with dots. Therefore, the aforementioned problem that the structure of the code is noticeable is somewhat mitigated. However, since the information is embedded depending on the presence or absence of dots, the number of dots to be printed changes depending on the information to be embedded (coordinate information and identification information), and the toner area (toner coverage) on the paper surface varies. I was sorry. As a result, for example, a two-dimensional code pattern printed on the background looks dark in a certain printed document, but the two-dimensional code pattern looks thin in another printed document, resulting in an image that is difficult for the user to use. There was a problem.

  In the technique of Patent Document 2, the appearance of the two-dimensional code pattern also changes depending on the information to be embedded. That is, depending on the information to be embedded, there are cases where the locations where dots are printed are concentrated inside the two-dimensional code. For example, the area where the identification information is embedded is common among a plurality of two-dimensional codes printed on the paper. Therefore, when the concentration of dots occurs in the region where the identification information is embedded, periodic image density fluctuations occur at intervals equal to the size of the two-dimensional code. The fluctuation of the image density appears as unevenness to human eyes, which causes a problem that the user is uncomfortable.

The present invention has been made to solve the technical problems as described above, and its purpose is to prevent fluctuations in the toner area between media when printing an image encoded with information on the media. There is to do.
Another object of the present invention is to prevent occurrence of toner bias in a medium when an image encoded with information is printed on the medium.

  For this purpose, in the present invention, when generating a code image, the original position code or identification information is converted in accordance with the arrangement position. That is, the image generation apparatus of the present invention identifies position code acquisition means for acquiring position codes obtained by encoding information indicating positions on a medium having a spread in two different directions, and document data printed on the medium. And an identification code acquisition means for acquiring an identification code obtained by encoding information for identifying a medium and a position code are two-dimensionally arranged in two directions at predetermined intervals, and the identification code is converted into a position code. Code plane generating means for generating a code plane that is two-dimensionally arranged adjacently and whose position code or identification code is converted according to the position of the arrangement, and code image generation that generates a code image by imaging the code plane Means.

  For example, the image generation apparatus converts the bit value included in the arrangement area of the identification code according to a predetermined rule according to the position in the X direction and the Y direction. Then, the appearance probabilities of the bit value “0” and the bit value “1” in the arrangement area of the identification code are made to be substantially equal. That is, the appearance of the code image in the printed image is made uniform. Here, among the predetermined rules, as the conversion method (conversion processing), bit value inversion, exclusive OR (EXOR) with a predetermined coefficient, or the like can be considered. Further, as the conversion cycle (conversion condition), a unit of a block defined by a synchronization code, a unit of position information, and the like can be considered.

  The present invention can also be understood as an information reading device that reads information from a code image printed on a medium. In this case, the information reading apparatus of the present invention includes an image reading unit that reads the code image from the medium on which the code image is printed, and a code that acquires the code represented by the code image from the code image read by the image reading unit. An acquisition unit, a code conversion unit that converts the code acquired by the code acquisition unit according to the print position on the medium of the code image that is the source of the code, and a predetermined code from the code converted by the code conversion unit Information acquisition means for acquiring information.

  Furthermore, the present invention can also be regarded as a print medium. In that case, the print medium of the present invention has spread in two different directions, and a code image obtained by imaging a predetermined code is printed in each of a plurality of regions arranged two-dimensionally along the two directions. The plurality of areas are a first area on which a code image obtained by imaging a predetermined code as it is and a code obtained by imaging a code obtained by inverting a code value constituting the predetermined code. And a second area where the image is printed.

  Furthermore, the present invention can also be understood as a method for generating an image. In that case, the image generation method of the present invention obtains a position code obtained by encoding information indicating each position on a medium having a spread in two different directions, and information for identifying document data to be printed on the medium. Or a step of obtaining an identification code obtained by encoding information for identifying a medium, the position code is two-dimensionally arranged along two directions at a predetermined interval, and the identification code is adjacent to the position code, and The method includes a step of generating code planes arranged two-dimensionally in a state of being converted according to the position code, and a step of generating a code image by imaging the code plane.

  On the other hand, the present invention can also be understood as a program for causing a computer to realize a predetermined function. In that case, the program of the present invention identifies a function for acquiring a position code obtained by encoding information indicating each position on a medium having a spread in two different directions, and document data printed on the medium. A function of acquiring an identification code obtained by encoding information or information for identifying a medium, a position code is two-dimensionally arranged in two directions at a predetermined interval, and the identification code is adjacent to the position code, and And a function of generating a code plane arranged two-dimensionally in a state converted according to the position code.

  According to the present invention, when an image in which information is encoded is printed on a medium, it is possible to prevent fluctuations in toner area between the media.

The best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described below in detail with reference to the accompanying drawings.
FIG. 1 shows a system configuration to which the present embodiment is applied. This system is configured by connecting a terminal device 10, a document repository 20, an identification information management server 30, and an image forming apparatus 40 to a network 90. The system also includes a printed document 50 and a pen 60 with a scanner.

The terminal device 10 is a computer device used by a user to instruct printing of an electronic document. For example, a PC (Personal Computer) is exemplified.
The document repository 20 is a server that stores electronic documents. An electronic document is provided in response to a request made by the user using the terminal device 10.
The identification information management server 30 is a server that manages identification information in a two-dimensional code image embedded in the print document 50. It also has a function of generating such a two-dimensional code image.
The image forming apparatus 40 prints an image of an electronic document on which a two-dimensional code image is superimposed.
The print document 50 is a medium such as paper on which an image is printed by the image forming apparatus 40. As an image, an image of an electronic document on which a two-dimensional code image is superimposed is printed.
The pen 60 with a scanner is a pen device that reads handwriting information when a character or a graphic is recorded on the print document 50.

The outline of the operation of this system will be described below.
First, the user instructs the terminal device 10 to access the document repository 20 and acquire information on an electronic document managed by the terminal repository 10. Thereby, the terminal device 10 displays the information of the electronic document on the display device, for example. Then, the user selects a desired electronic document from among the displayed electronic documents. Upon receiving this selection, the document repository 20 transmits the selected electronic document to the identification information management server 30. At this time, the user may designate various parameters (printing parameters) for printing on the terminal device 10 and instruct to transmit them to the identification information management server 30. Here, the print parameters include a paper size, the number of copies, a printing direction (vertical / horizontal), and the like.

  Next, when receiving the electronic document, the identification information management server 30 generates identification information for each unit of identification information. Here, as a unit for giving identification information, for example, a medium page, an entire medium necessary for printing an electronic document, an electronic document page, and an entire electronic document can be considered. Which one is to be adopted as the identification information addition unit may be determined in advance by the system, or may be designated by the user who prints the electronic document. As a method for generating identification information, for example, a method of acquiring unused identification information from an identification information database (not shown) or a method of generating identification information using a hash value of an electronic document can be considered.

Further, the identification information management server 30 registers the correspondence between the generated identification information and the attribute information of the electronic document in the identification information database. Here, the attribute information of the electronic document includes, for example, the storage location (URL, etc.) of the electronic document, the information of the user who instructed printing (user ID, etc.), and the identification information of the image forming apparatus that prints this electronic document. . When the identification information is given in a smaller unit than the entire electronic document, it is preferable that the identification information of the given unit in the electronic document is also registered as one of the attribute information. For example, this corresponds to a page number when the unit of providing identification information is a page. Alternatively, not only the attribute information but also the electronic document data itself may be registered in the identification information database.
Further, the identification information management server 30 generates a position information group to be printed on each page, and generates a two-dimensional code image representing the position information and the identification information. Then, the two-dimensional code image and the electronic document are transmitted to the image forming apparatus 40.

  As a result, the image forming apparatus 40 superimposes and prints the electronic document image and the two-dimensional code image, and outputs a print document 50. That is, a two-dimensional code image including identification information and position information can be superimposed and printed out on the electronic document selected by the user from the existing document repository 20.

Here, the image forming apparatus 40 has a two-dimensional code image that has a maximum absorption rate of, for example, 7% or less in the visible light region (400 nm to 700 nm) and an absorption rate of, for example, 30 in the near infrared region (800 nm to 1000 nm). % Of invisible toner. The invisible toner has an average dispersion diameter in the range of 100 nm to 600 nm in order to enhance the near infrared light absorption capability necessary for machine reading of an image. Here, “visible” and “invisible” are not related to whether they can be recognized visually. “Visible” and “invisible” are distinguished based on whether or not an image formed on a medium can be recognized by the presence or absence of color developability caused by absorption of a specific wavelength in the visible light region.
In this specification, information is read from a two-dimensional code image by irradiating infrared light, but information is read by irradiating other specific wavelength light, for example, ultraviolet light. Also good.
Further, black toner can be used as a configuration that does not use invisible toner. Since black toner used in ordinary printers and copiers contains carbon that absorbs infrared light, black toner can be used as an infrared absorbent. When black toner is used, the two-dimensional code image is more visible than invisible toner, so that the effect of the present invention is more effective. When black toner is used to form a two-dimensional code image, the electronic document image is preferably formed with a toner (yellow, magenta, cyan) having a lower infrared absorptance than black toner. Alternatively, the electronic document image may be formed using black toner that does not absorb infrared light. If it is not necessary to reproduce the locus on the electronic document image, black toner can also be used to form the electronic document image.

Thereafter, it is assumed that the user who has acquired the print document 50 writes the print document 50 with the pen 60 with a scanner. Then, the pen with scanner 60 obtains a writing locus from position information in the two-dimensional code image read by the scanner at the time of writing. Further, the identification information in the two-dimensional code image read by the scanner is transmitted to the identification information management server 30.
Thereby, the pen 60 with a scanner can specify the electronic document corresponding to the identification information, and can display it on the terminal device 10, for example. In addition, when the identification information addition unit is a page, the page in the electronic document corresponding to the identification information can be specified. In this case, writing trajectory data can be added to the page indicated by the identification information in the electronic document, for example, as an overlay plane image. In addition, the attribute information of the electronic document corresponding to the identification information can be acquired instead of the electronic document itself. In this case, electronic document data can be acquired from the storage location included in the attribute information, and writing trajectory data can be added to the data.

  Further, by using the attribute information of the electronic document managed in association with the identification information, leakage of information printed on the print document 50 can be dealt with. For example, as attribute information corresponding to the identification information read from the print document 50, information of the user who has instructed the output of the print document 50 can be obtained from the identification information management server 30. Therefore, if the print document 50 is leaked, it can be used as a clue to ascertain the leakage path by asking the user who has instructed printing the circumstances. Further, based on the identification information of the image forming apparatus included in the attribute information, it is possible to check which image forming apparatus the print document 50 is output from. Therefore, this is also useful information for specifying the leakage route and the like.

  Further, based on the identification information read from the two-dimensional code image on the print document 50, an electronic document (original electronic document) that is the basis of the print document 50 can be acquired. Therefore, for example, it is possible to obtain a clearer copy by printing the original electronic document instead of copying the print document 50.

  Furthermore, by using the attribute information of the electronic document associated with the identification information, it is possible to manage the user's usage mode for the print document 50. In the electronic document attribute information, for example, the information of the user who instructed printing is registered, and as one of such information, information on operations permitted for the user with respect to the print document 50 is registered. Keep it. Here, the operation information is information regarding use conditions when the user uses the print document 50. For example, there are settings for whether or not the print document 50 can be copied and whether or not the print document 50 can be written. Accordingly, an application that uses the read information can determine whether or not an operation requested by the user may be executed according to the identification information read from the print document 50. A server for managing the user's use authority for each electronic document or print document 50 may be prepared separately, and the application may acquire the user's authority from the server using the identification information as a key.

In the above description, the identification information is described as being associated with the identification information management server 30 by the user who instructed printing, the image forming apparatus that has output the print, the usage conditions of the user for the document, but the present invention is not limited to this. . That is, the user, the image forming apparatus, the usage conditions, and the like may be included in the identification information and embedded in the two-dimensional code image.
1 is configured to include the document repository 20, the identification information management server 30, and the image forming apparatus 40 as separate apparatuses, this is just an example. Various other system configurations such as a configuration in which the document repository 20 and the identification information management server 30 are combined into one server, a configuration in which the identification information management server 30 and the image forming device 40 are combined into one device, and the like. Can be taken.

In the present embodiment, in such a system, the identification information management server 30 generates a two-dimensional code image with a small change in the toner area ratio. Therefore, the identification code included in the two-dimensional code image is converted according to the arrangement position. In this case, there are a case where a conversion condition and a conversion process (hereinafter referred to as “conversion rule”) are determined, and a case where any conversion rule can be adopted.
Therefore, in the following, the former will be described in detail as the first embodiment, and the latter as the second embodiment.

[First Embodiment]
FIG. 2 is a diagram illustrating a configuration of an image generation unit in the identification information management server 30 according to the first embodiment.
The identification information encoding unit 31 encodes the input identification information and outputs an identification code. The identification information encoding unit 31 can be considered to have a function as an identification code acquisition unit from the viewpoint of acquiring an identification code.
Here, as the identification information, information for identifying a medium on which a two-dimensional code image including the identification information is printed can be considered. Further, it may be information for identifying an electronic document or a page of the electronic document that is a source of a document image printed together with the two-dimensional code image.

Here, for encoding such identification information, an error detection code such as a known CRC (Cyclic Redundancy Check) code or an error correction code such as an RS code or a BCH code can be used. For example, consider a case where identification information is encoded using an RS (16, 10) code having a block length of 5 bits (code block length = 16 blocks, information block length = 10 blocks). In this case, even if an error due to noise or the like occurs in 3 blocks (15 bits), the error can be corrected. Information can be embedded in 50 bits (= 5 bits × 10 blocks) out of 80 bits (= 5 bits × 16 blocks) of the code block. If 8 bits out of 50 bits are used for error detection, the remaining 42 bits can be used for identification information. That is, about 4.4 trillion (2 ⁴² ) kinds of identification information can be embedded.

The position code generation unit 32 encodes position information (coordinates) of the partial area on the medium surface or position information indicating the partial area of the electronic document printed together with the position information, and outputs a position code. In addition, it can be considered that this position code generation part 32 has a function as a position code acquisition means from a viewpoint of acquiring a position code.
Here, the error detection code and the error correction code described above can be used for encoding such position information, but in the present embodiment, the position information is encoded with an M-sequence code. To do.
The M-sequence code refers to a sequence having a maximum period (2p-1) among sequences generated from the following p-order recurrence formula (also referred to as a pseudo-random sequence).

For example, when p = 5, C1 = 1, C2 = 1, C3 = 1, C4 = 0, and C5 = 1, an M sequence “0111000101011010000110010011111” (length 2 ⁵ −1 = 31) is generated. The partial series of length p taken from different positions of the M series never match. Using this property, position information can be encoded.
For example, it is assumed that one bit of the M series is expressed by an image pattern of 0.3 mm. In this case, in order to express 297 mm in the longitudinal direction of the paper size A4, as shown below, encoding can be performed with a 10th order M-sequence.
(2 ¹⁰ -1) x 0.3 mm = 1023 x 0.3 mm = 306.9 mm
By embedding this M sequence in the X direction and the Y direction, the position of the plane can be encoded.

The code plane generation unit 33 generates a code plane in which an identification code and a position code are arranged. The code plane generation unit 33 includes a code arrangement unit 33a, a position acquisition unit 33b, a code conversion unit 33c, and a synchronous code arrangement unit 33d.
The code arrangement unit 33a arranges the identification code and the position code on the code plane. Here, the code plane is a plane expressed by a two-dimensional array, and an identification code and a code value of a position code are stored in each element of the two-dimensional array.
The position acquisition unit 33b acquires the arrangement position of the identification code on the code plane, and determines whether the arrangement position matches the conversion condition. Here, the conversion condition is, for example, a condition such as “even number in the X direction and odd number in the Y direction, or odd number in the X direction and even number in the Y direction”, and is determined in advance in the system.

The code conversion unit 33c converts the code value of the identification code arranged on the code plane when the arrangement position acquired by the position acquisition unit 33b matches the conversion condition. Here, as a code value conversion method (conversion processing), a method in which the presence or absence of an image pattern at each bit position of the identification code is inverted when the identification code is imaged can be considered.
The synchronization code arrangement unit 33d arranges a synchronization code for rotation detection in order to detect the rotation of the code plane. If there is no problem in reading the identification code and the position code without arranging the synchronization code, the synchronization code arrangement unit 33d is not necessarily provided.

The code image generation unit 34 generates a two-dimensional code image by converting the code values constituting the code plane into an image. The code image generation unit 34 includes a code reference unit 34a, a pattern storage unit 34b, a pattern selection unit 34c, and an image conversion unit 34d.
The code reference unit 34a obtains a code value constituting the code plane generated by the code plane generation unit 33.
The pattern storage unit 34b stores a plurality of types of image patterns for representing code values as images.
The pattern selection unit 34c refers to the code value acquired by the code reference unit 34a and extracts an image pattern corresponding to the code value from the pattern storage unit 34b.
The image conversion unit 34d arranges the image pattern on the image plane using the image pattern selected by the pattern selection unit 34c.

  These functional parts are realized by cooperation between software and hardware resources. Specifically, a CPU (not shown) of the identification information management server 30 performs an identification information encoding unit 31, a position code generation unit 32, a code plane generation unit 33 (including internal functions), and a code image generation unit 34 (internal (Including functions) are read from the external storage device to the main storage device for processing.

Next, an example of code value conversion on the code plane in the present embodiment will be described.
FIG. 3 schematically shows a part of the code plane. In the figure, the horizontal direction is the X direction and the vertical direction is the Y direction.
First, FIG. 3A shows a code plane before conversion by the code conversion unit 33c.
Among these, the diagram on the left shows the arrangement of the identification code, position code, and synchronization code on the code plane. That is, in the code plane, the synchronization codes 3a are arranged at predetermined intervals in the X direction and the Y direction. Then, an X-direction position code 3b is arranged in a region sandwiched between the synchronization codes 3a arranged in the X direction. Further, the Y-direction position code 3c is arranged in a region sandwiched between the synchronization codes 3a arranged in the Y direction. Further, an identification code 3d is arranged in the lower right area of the synchronization code 3a.

  Further, the right diagram specifically shows the code values in the blocks surrounded by the thick lines in the left diagram. In this example, one block is composed of 10 bits × 10 bits. In the block, the code in the upper left 2 × 2 bit region 3p corresponds to the synchronization code 3a. Here, the synchronization code is represented by four “2” s which are special information. The code in the upper right 2 bits × 8 bits area 3q corresponds to the X-direction position code 3b. The code in the lower left 8 bits × 2 bits area 3r corresponds to the Y-direction position code 3c. Further, the code in the lower right 8 bit × 8 bit region 3s corresponds to the identification code 3d. In this example, as for the bit value included in the identification code 3d, “0” is overwhelmingly larger than “1”. Accordingly, the arrangement region of the identification code 3d in the left diagram is represented by thin shading.

On the other hand, FIG. 3B shows a code plane after conversion by the code conversion unit 33c. Here, it is assumed that the conversion condition is “even number in the X direction and odd number in the Y direction, or odd number in the X direction and even number in the Y direction”, and the conversion process is “sign value inversion process”. Suppose there is.
Among these, the left diagram shows the arrangement of the identification code, the position code, and the synchronization code on the code plane, as in FIG.

  Further, the right diagram specifically shows the code values in the blocks surrounded by the thick lines in the left diagram. As in FIG. 3A, one block is composed of 10 bits × 10 bits. In the block, the synchronization code 3a in the upper left 2 bits × 2 bits region, the X direction position code 3b in the upper right 2 bits × horizontal 8 bits region, and the Y direction in the lower left vertical 8 bits × horizontal 2 bits region The use position code 3c has the same value as that in FIG. 3A and is not converted. On the other hand, the code value inversion process is performed on the identification code 3d in the lower right 8 bits × 8 bits area. Thereby, the bit value included in the identification code 3d is “1” overwhelmingly larger than “0”. Therefore, a part of the arrangement region of the identification code 3d in the left diagram is represented by dark shading. In this case, as described above, the conversion condition “even number in the X direction and odd number in the Y direction, or odd number in the X direction and even number in the Y direction” is specified. The blocks are distributed as shown in the figure.

Next, operations of the position acquisition unit 33b and the code conversion unit 33c in the present embodiment will be described. However, the conversion rules are not limited to specific ones here.
FIG. 4 is a flowchart showing operations of the position acquisition unit 33b and the code conversion unit 33c. In the following, an index representing the order of the blocks in the X direction in FIG. 3 is X, and an index representing the order of the Y direction is Y.

First, “1” is set to Y (step 301), and “1” is set to X (step 302). Then, the position acquisition unit 33b determines whether (X, Y) satisfies a predetermined conversion condition (step 303).
As a result, when it is determined that (X, Y) satisfies the conversion condition, the code conversion unit 33c is instructed to convert the identification code. As a result, the code conversion unit 33c performs a predetermined conversion process on the identification code in the block (X, Y) (step 304). Then, the position acquisition unit 33b adds 1 to X (step 305).
On the other hand, if it is determined that (X, Y) does not satisfy the predetermined condition, the position acquisition unit 33b does not instruct the code conversion unit 33c to convert the identification code, and adds 1 to X (step S1). 305).

Then, the position acquisition unit 33b determines whether X exceeds M (step 306). If X does not exceed M, the processes in steps 303 to 305 are repeated. Thereafter, when X exceeds M, 1 is added to Y (step 307).
Further, the position acquisition unit 33b determines whether Y exceeds N (step 308). If Y does not exceed N, the processes in steps 302 to 307 are repeated. Thereafter, when Y exceeds N, the process is terminated.

Next, reading of information from the print document 50 on which a two-dimensional code image obtained by imaging the code subjected to the conversion process in this way is printed will be described.
FIG. 5 shows a configuration of a pen 60 with a scanner which is one of information reading devices.
As illustrated, the pen 60 with a scanner includes a control circuit 61 that controls the operation of the entire pen. The control circuit 61 includes an image processing unit 61a that detects a two-dimensional code image from an input image and a data processing unit 61b that decodes the two-dimensional code image and acquires writing information.
The control circuit 61 is connected to a pressure sensor 62 that detects a writing operation by the pen 60 with a scanner by a pressure applied to the pen tip 69. Further, an infrared LED 63 that irradiates infrared light onto the medium and an infrared CMOS 64 that inputs an image are also connected. Furthermore, a writing information memory 65 for storing writing information, a communication circuit 66 for communicating with an external device, a battery 67 for driving the pen, and a pen ID for storing pen identification information (pen ID) A memory 68 is also connected.

  Of these, the infrared CMOS 64 or the image processing unit 61a (portion relating to image input) can be considered to have a function as image reading means. Further, it can be considered that the image processing unit 61a or the data processing unit 61b (part relating to detection of a code value from a two-dimensional code image) has a function as a code acquisition unit. Further, it can be considered that the data processing unit 61b (part relating to code value conversion) has a function as code conversion means. Furthermore, it can be considered that the data processing unit 61b (part relating to detection of information from the converted code value) has a function as information acquisition means.

Here, an outline of the operation of the pen 60 with a scanner will be described.
When writing is performed by the pen 60 with a scanner, the pressure sensor 62 connected to the pen tip 69 detects the writing operation. Thereby, the infrared LED 63 is turned on, and the infrared CMOS 64 captures an image on the medium by the CMOS sensor.
The infrared LED 63 is pulsed in synchronization with the shutter timing of the CMOS sensor in order to reduce power consumption.
The infrared CMOS 64 uses a global shutter type CMOS sensor that can simultaneously transfer captured images. A CMOS sensor having sensitivity in the infrared region is used. In order to reduce the influence of disturbance, a visible light cut filter is disposed on the entire surface of the CMOS sensor. The CMOS sensor captures an image with a period of about 70 fps to 100 fps (frame per second). Note that the image sensor is not limited to a CMOS sensor, and other image sensors such as a CCD may be used.

When the image thus captured is input to the control circuit 61, the control circuit 61 acquires a two-dimensional code image from the captured image. And it decodes and acquires the writing information (coordinate information and identification information) embedded in the two-dimensional code image.
Hereinafter, the operation of the control circuit 61 at this time will be described in detail.
FIG. 6 is a flowchart showing the operation of the control circuit 61.
First, the image processing unit 61a inputs an image (step 601), and performs a process for removing noise included in the image (step 602). Here, the noise includes variations in CMOS sensitivity, noise generated by an electronic circuit, and the like. The type of noise removal processing should match the characteristics of the imaging system of the pen 60 with a scanner, but sharpening processing such as blurring processing and unsharp masking can be applied.

  Next, the image processing unit 61a detects a dot pattern from the image (step 603). For example, the dot pattern portion and the background portion are separated by binarization processing, and the dot pattern can be detected from each binarized image position. When a binarized image contains a lot of noise components, for example, it is necessary to combine filter processing for determining a dot pattern based on the area and shape of the binary image.

The data processing unit 61b receives the dot pattern detected by the image processing unit 61a and converts it into a code value (step 604). Specifically, a code plane including a code value having a dot position “1” and a dot-free position “0” is generated.
Further, the data processing unit 61b detects a synchronization code on this code plane (step 605). Then, the position of the identification code and the position code is specified by this synchronization code and acquired (step 606). Further, position information is acquired by collating the acquired position code with the M series used for image generation (step 607).

  Then, the data processing unit 61b determines whether or not this position information satisfies a predetermined conversion condition (step 608). Here, the predetermined conversion condition is the same condition as used in step 303 of FIG.

As a result, when it is determined that the conversion condition is not satisfied, RS decoding processing is performed on the identification code, and identification information is acquired (step 610).
On the other hand, if it is determined that the conversion condition is satisfied, an inverse conversion process is performed on the identification code (step 609). Here, the reverse conversion process is a process for performing a reverse conversion to the conversion process used in step 304 of FIG. Then, an RS decoding process is performed on the identification code after the inverse transformation to obtain identification information (step 610).
Finally, the data processing unit 61b stores the writing information including the identification information and the position information in the writing information memory 65 (Step 611).
Accordingly, the communication circuit 66 transmits the writing information stored in the writing information memory 65 to the external device.

  By the way, although the conversion rule is not clearly shown in the flowcharts of FIGS. 4 and 6, various conversion rules can be used. An example is the conversion rule shown in FIG. In this case, the “conversion condition” in step 303 in FIG. 4 and step 608 in FIG. 6 is “even number in X direction and odd number in Y direction, or odd number in X direction and even number in Y direction”. It is a condition. Further, the “conversion process” in step 304 in FIG. 4 and the “inverse conversion process” in step 609 in FIG. 6 are “sign value inversion processes”.

In addition to the above, the following conversion rules are also conceivable.
For example, an exclusive OR of a sequence of code values and a predetermined coefficient is obtained, and this is used as a new sequence of code values. In this case, as the “conversion condition” in step 303 in FIG. 4 and step 608 in FIG. Further, as the “conversion process” in step 304 in FIG. 4 and the “inverse conversion process” in step 609 in FIG. 6, “exclusive OR calculation process of code value sequence and predetermined coefficient” is adopted. Can do.

  It is also conceivable that an operation using the value (X, Y) obtained from the position code is performed on the identification codes at all the arrangement positions, and the resulting code is used as a new identification code. In this case, in Step 303 of FIG. 4 and Step 608 of FIG. 6, the determination result is “Yes” for all (X, Y). Further, “calculation processing using (X, Y)” is adopted as the “conversion processing” in step 304 of FIG. 4, and “inverse conversion processing” in step 609 of FIG. The “inverse arithmetic processing” can be employed.

  As described above, in the present embodiment, the identification code is converted according to the arrangement position, and the converted identification code is imaged to generate a two-dimensional code image. As a result, when this image is printed on a medium, fluctuations in the toner area between the media can be prevented. In addition, it is possible to prevent the occurrence of toner bias in the medium.

Here, the effect by this Embodiment is demonstrated concretely.
FIG. 7 shows an example of a two-dimensional code image generated when the code conversion unit 33c does not invert the code value.
FIG. 7A shows each bit value shown on the right side of FIG. 3A by dot ON / OFF. In FIG. 7A, since the code value of the identification code is not inverted, the dot ON / OFF in the identification code arrangement region is the same pattern.
FIG. 7B shows how the code pattern looks when the dot pattern of FIG. 7A is actually printed on a medium. In particular, since the same dot pattern is periodically printed in the portion corresponding to the identification code arrangement area, the image gives an unpleasant feeling to the user.

On the other hand, FIG. 8 shows an example of a two-dimensional code image generated when the code value is inverted by the code conversion unit 33c.
FIG. 8 (a) is obtained by inverting the dot ON / OFF in FIG. 7 (a) only for the bit inversion identification code arrangement region surrounded by the thick line.
FIG. 8B shows how the code pattern looks when the dot pattern of FIG. 8A is actually printed on a medium. In particular, since the same dot pattern is not periodically printed in the portion corresponding to the identification code arrangement region, the image is reduced in discomfort given to the user.

  By the way, in FIG.7 and FIG.8, ON / OFF of the dot was used in order to image a code value. That is, “with dot” and “without dot” are stored as image patterns in the pattern storage unit 34b, and the pattern selection unit 34c sets “with dot” to bit “0” for bit “1”. On the other hand, “no dot” was selected. However, the image pattern used for imaging the code value is not limited to this.

First, an image pattern in which one image element (for example, a dot) having a predetermined shape is shifted from the reference position by the same amount in different directions may be used. For example, it is possible to express four types of information by shifting the same amount from the reference position to the right, shifting upward, shifting to the left, and shifting downward. To do.
Second, an image pattern in which a plurality of image elements (for example, dots) having a predetermined shape are arranged at different positions may be used. For example, image elements can be arranged at nine locations in the minimum unit of information embedding. Then, by selecting two of the nine locations and arranging image elements, 36 (= ₉ C ₂ ) information can be expressed.

[Second Embodiment]
FIG. 9 is a diagram illustrating a configuration of an image generation unit in the identification information management server 30 according to the second embodiment.
This image generation unit is different from the configuration of the image generation unit in the first embodiment in that the code plane generation unit 33 includes a conversion code arrangement unit 33e. The conversion code arrangement unit 33e arranges the conversion code on the code plane. Here, the conversion code is obtained by encoding information for identifying a conversion rule used for conversion of an identification code.
As for the conversion code arrangement unit 33e, a CPU (not shown) of the identification information management server 30 reads a program for realizing the function from the external storage device into the main storage device and performs processing.

Next, an example of code value conversion on the code plane in the present embodiment will be described.
FIG. 10 schematically shows a part of the code plane. In the figure, the horizontal direction is the X direction and the vertical direction is the Y direction.
First, FIG. 10A shows a code plane before conversion by the code conversion unit 33c.
Among these, the diagram on the left shows the arrangement of the identification code, position code, synchronization code, and conversion code on the code plane. That is, in the code plane, the synchronization codes 3a are arranged at predetermined intervals in the X direction and the Y direction. Then, an X-direction position code 3b is arranged in a region sandwiched between the synchronization codes 3a arranged in the X direction. Further, the Y-direction position code 3c is arranged in a region sandwiched between the synchronization codes 3a arranged in the Y direction. Further, an identification code 3d is arranged in the lower right area of the synchronization code 3a. In this embodiment, in addition to these codes, the conversion code 3e is arranged in the lower right area of the identification code 3d.

  Further, the right diagram specifically shows the code values in the blocks surrounded by the thick lines in the left diagram. In this example, one block is composed of 10 bits × 10 bits. In the block, the code in the upper left 2 × 2 bit region 3p corresponds to the synchronization code 3a. Here, the synchronization code is represented by four “2” s which are special information. The code in the upper right 2 bits × 8 bits area 3q corresponds to the X-direction position code 3b. The code in the lower left 8 bits × 2 bits area 3r corresponds to the Y-direction position code 3c. Furthermore, the code in the lower right 2 × 2 bit area 3u corresponds to the conversion code 3e. Furthermore, the code in the area 3t excluding these areas corresponds to the identification code 3d. In this example, as for the bit value included in the identification code 3d, “0” is overwhelmingly larger than “1”. Accordingly, the arrangement region of the identification code 3d in the left diagram is represented by thin shading.

On the other hand, FIG. 10B shows a code plane after conversion by the code conversion unit 33c. Here, it is assumed that the conversion condition is “even number in the X direction and odd number in the Y direction, or odd number in the X direction and even number in the Y direction”, and the conversion process is “sign value inversion process”. Suppose there is.
Among these, the left diagram shows the arrangement of the identification code, position code, synchronization code, and conversion code on the code plane, as in FIG. 10A.

  Further, the right diagram specifically shows the code values in the blocks surrounded by the thick lines in the left diagram. As in FIG. 10A, one block is composed of 10 bits × 10 bits. In the block, the synchronization code 3a in the upper left 2 bits × 2 bits region, the X direction position code 3b in the upper right 2 bits × horizontal 8 bits region, and the Y direction in the lower left vertical 8 bits × horizontal 2 bits region The position code 3c and the conversion code 3e in the lower right 2 bits × 2 bit region have the same values as in FIG. 10A and are not converted. On the other hand, the code value inversion process is performed on the identification codes 3d in the areas excluding those areas. Thereby, the bit value included in the identification code 3d is “1” overwhelmingly larger than “0”. Therefore, a part of the arrangement region of the identification code 3d in the left diagram is represented by dark shading. In this case, as described above, the conversion condition “even number in the X direction and odd number in the Y direction, or odd number in the X direction and even number in the Y direction” is specified. The blocks are distributed as shown in the figure.

Next, operations of the position acquisition unit 33b, the code conversion unit 33c, and the conversion code arrangement unit 33e in the present embodiment will be described. However, the conversion rules are not limited to specific ones here.
FIG. 11 is a flowchart illustrating operations of the position acquisition unit 33b, the code conversion unit 33c, and the conversion code arrangement unit 33e.
First, the position acquisition unit 33b and the code plane perform steps 321 to 324. However, these processes are the same as steps 301 to 304 in FIG.

When the determination result in step 323 is “No”, or after the processing in step 324, in the present embodiment, the conversion code arrangement unit 33e arranges the conversion code indicating the conversion rule on the code plane (step 325). ). Here, the conversion code is obtained by encoding conversion rule information including the conversion condition used in step 323 and the conversion process used in step 324. Note that the conversion condition used in step 323 and the conversion process used in step 324 can be selected from a plurality of conversion rules exemplified in the first embodiment.
After that, the position acquisition unit 33b performs the processing of Steps 326 to 329, which are the same as Steps 305 to 308 of FIG.

  Next, reading of information from the print document 50 on which a two-dimensional code image obtained by imaging the code subjected to the conversion process in this way is printed will be described. As the information reading device, the same pen 60 with a scanner as that in the first embodiment can be used, and the description of the configuration is omitted.

Here, an outline of the operation of the pen 60 with a scanner will be described.
When writing is performed by the pen 60 with a scanner, the pressure sensor 62 connected to the pen tip 69 detects the writing operation. Thereby, the infrared LED 63 is turned on, and the infrared CMOS 64 captures an image on the medium by the CMOS sensor.
When the image thus captured is input to the control circuit 61, the control circuit 61 acquires a two-dimensional code image from the captured image. And it decodes and acquires the writing information (coordinate information and identification information) embedded in the two-dimensional code image.

Hereinafter, the operation of the control circuit 61 at this time will be described.
FIG. 12 is a flowchart showing the operation of the control circuit 61.
First, the image processing unit 61a and the data processing unit 61b perform the processing of steps 621 to 625. However, these processes are the same as steps 601 to 605 in FIG.
Next, the data processing unit 61b specifies the positions of the identification code, the position code, and the conversion code based on the synchronization code detected in step 625, and acquires them (step 626). Further, position information is acquired by collating the acquired position code with the M sequence used for image generation. Further, a conversion rule is obtained based on the conversion code (step 627).

Then, the data processing unit 61b determines whether or not the position information satisfies the conversion condition in the conversion rule obtained in Step 627 (Step 628).
As a result, if it is determined that the conversion condition is not satisfied, the RS decoding process is performed on the identification code, and the identification information is acquired (step 630).
On the other hand, if it is determined that the conversion condition is satisfied, the identification code is subjected to inverse conversion processing for the conversion processing in the conversion rule obtained in step 627 (step 629). Then, an RS decoding process is performed on the identification code after the inverse transformation to obtain identification information (step 630).
Finally, the data processing unit 61b stores the writing information including the identification information and the position information in the writing information memory 65 (step 631).
Accordingly, the communication circuit 66 transmits the writing information stored in the writing information memory 65 to the external device.

  As described above, in the present embodiment, when the identification code is converted according to the arrangement position, the conversion code indicating the conversion rule is arranged. As a result, any conversion rule can be selected according to the situation as a conversion rule for converting the identification code for preventing the toner area variation between the media and the occurrence of toner bias in the medium. It became so.

In the present embodiment, the conversion code indicates a conversion rule including a conversion condition and a conversion process, but may indicate either a conversion condition or a conversion process.
Also in the present embodiment, when the converted code value is converted into an image, various image patterns can be used as in the first embodiment.

  Furthermore, in the first and second embodiments described so far, the identification code is converted according to the arrangement position, but the conversion target code is not limited to this. For example, the position code may be converted according to the arrangement position. The position code does not embed the same information at all positions on the medium like the identification code. However, depending on the method of generating the position code, for example, some of the position codes arranged in the X direction may be the same, or some of the position codes arranged in the Y direction may be the same. . In such a case, it is possible to minimize the occurrence of the same pattern periodically by converting the position code according to the arrangement position. In this case, for example, the information can be read without any problem by embedding the conversion rule for the position code in the medium using the conversion code or the like.

1 is a diagram showing an overall configuration of a system to which an embodiment of the present invention is applied. It is the block diagram which showed the function structure of the image generation part in the 1st Embodiment of this invention. It is the figure which showed the example of the code plane in the 1st Embodiment of this invention. It is the flowchart which showed operation | movement of the image generation part in the 1st Embodiment of this invention. It is the figure which showed the structure of the pen with a scanner in embodiment of this invention. It is the flowchart which showed operation | movement of the pen with a scanner in the 1st Embodiment of this invention. It is the figure which showed the example of the two-dimensional code image in case the conversion by a code conversion part is not performed. It is the figure which showed the example of the two-dimensional code image at the time of converting by a code conversion part. It is the block diagram which showed the function structure of the image generation part in the 2nd Embodiment of this invention. It is the figure which showed the example of the code plane in the 2nd Embodiment of this invention. It is the flowchart which showed operation | movement of the image generation part in the 2nd Embodiment of this invention. It is the flowchart which showed operation | movement of the pen with a scanner in the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Terminal device, 20 ... Document repository, 30 ... Identification information management server, 40 ... Image forming apparatus, 50 ... Print document, 60 ... Pen with scanner

Claims (16)

Position code acquisition means for acquiring a position code obtained by encoding information indicating each position on a medium having a spread in two different directions;
Information for identifying document data to be printed on the medium, or identification code acquisition means for acquiring an identification code obtained by encoding information for identifying the medium;
The position code is two-dimensionally arranged along the two directions at a predetermined interval, the identification code is two-dimensionally arranged adjacent to the position code, and the position code or the identification code is the arrangement position. Code plane generating means for generating a code plane converted according to
An image generation apparatus comprising: code image generation means for generating an image of the code plane by generating an image of the code plane.   The image generation apparatus according to claim 1, wherein the code plane generation unit generates the code plane in which a code value constituting the position code or the identification code is converted.   3. The image according to claim 2, wherein the code image generation means selects an image pattern corresponding to the code value from a plurality of image patterns, and images the code value using the image pattern. Generator.   The image generating apparatus according to claim 3, wherein the plurality of image patterns include an image pattern in which pixels are not arranged.   The image generating apparatus according to claim 3, wherein the plurality of image patterns include an image pattern in which one image element having a predetermined shape is arranged at a position shifted in the different direction by the same amount from the reference position.   The image generating apparatus according to claim 3, wherein the plurality of image patterns include image patterns in which a plurality of image elements having a predetermined shape are arranged at different positions.   The image generating apparatus according to claim 6, wherein the image element has a dot shape.   The code plane generation unit generates the code plane in which the identification code is converted according to the arrangement position specified based on the position code adjacent to the identification code. The image generating apparatus described.   2. The image according to claim 1, wherein the code plane generating unit generates the code plane in which a conversion code obtained by encoding information for identifying a conversion rule of the position code or the identification code is further arranged. Generator. Image reading means for reading the code image from the medium on which the code image is printed;
Code acquisition means for acquiring a code represented by the code image from the code image read by the image reading means;
Code conversion means for converting the code acquired by the code acquisition means in accordance with a print position on the medium of the code image that is the source of the code;
An information reading apparatus comprising: information acquisition means for acquiring predetermined information from the code converted by the code conversion means.   11. The information reading according to claim 10, wherein the code conversion unit converts a part of the code acquired by the code acquisition unit based on a conversion rule specified by another part of the code. apparatus. A print medium on which a code image obtained by imaging a predetermined code is printed in each of a plurality of regions that are spread in two different directions and are two-dimensionally arranged along the two directions,
The plurality of regions are:
A first region on which a code image obtained by directly imaging the predetermined code is printed;
And a second area on which a code image obtained by imaging a code obtained by inverting a code value constituting the predetermined code is printed. Obtaining a position code obtained by encoding information indicating each position on a medium having a spread in two different directions;
Obtaining information identifying document data to be printed on the medium, or an identification code obtained by encoding information identifying the medium;
The position code is two-dimensionally arranged along the two directions at a predetermined interval, and the identification code is two-dimensionally arranged adjacent to the position code and converted according to the position code. Generating a code plane;
And generating a code image by imaging the code plane.   14. The image generation method according to claim 13, wherein in the step of generating the code plane, the code plane on which a conversion code obtained by encoding information for identifying a conversion rule of the identification code is further arranged. On the computer,
A function of acquiring a position code obtained by encoding information indicating each position on a medium having a spread in two different directions;
A function of acquiring information for identifying document data to be printed on the medium, or an identification code obtained by encoding information for identifying the medium;
The position code is two-dimensionally arranged along the two directions at a predetermined interval, and the identification code is two-dimensionally arranged adjacent to the position code and converted according to the position code. A function to generate a code plane;
A program to realize   16. The program according to claim 15, wherein the function for generating the code plane generates the code plane in which a conversion code obtained by encoding information for identifying a conversion rule of the identification code is further arranged.

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