JP2018017844A - Image formation apparatus and image formation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation apparatus which reduces the stand-by time of calibration in direct printing.SOLUTION: A storage medium detection unit 100 detects that a portable storage medium 2 is attached. A file type identification unit 110 identifies the type of a file 200 stored in the portable storage medium 2 detected by the storage medium detection unit 100. A file content analysis unit 120 analyzes the contents of the file 200 in response to the type of the file 200 identified by the file type identification unit 110. A calibration table determination unit 130 determines the type of a gamma correction table 300 to be calibrated on the basis of the type of the file 200 and/or contents of the file 200 analyzed by the file content analysis unit 120. A calibration unit 140 calibrates the gamma correction table 300 corresponding to determination of the calibration table determination unit 130.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus and an image forming method, and more particularly to an image forming apparatus and an image forming method for performing calibration.

Conventionally, there are image forming apparatuses such as multifunction peripherals (MFPs) capable of printing documents and images.
Some of these image forming apparatuses have a calibration function for calibrating the input / output characteristics of the image forming unit, so-called “gamma correction”, when they change over time. As such a calibration, there is one that measures a current output color state using a density sensor in its own apparatus and corrects it to a target color value (output value).

There is also an image forming apparatus having a so-called “direct print” function in which a portable storage medium such as various memory cards is mounted on the image forming apparatus and a file designated by the user is printed without using a terminal such as a PC. . In such direct printing, particularly high color reproducibility is required.
However, the calibration as described above is executed at a specific frequency for each product. For this reason, the image forming unit is not always in the best state at the time of printing that requires high color reproducibility.
Therefore, conventionally, it is necessary to execute calibration every time direct printing is performed.

  With reference to Patent Document 1, when mounting of a portable storage medium is detected, a calibration operation is started at the stage where a file stored in the portable storage medium is detected, and the waiting time of the user is reduced. The technology is described.

JP 2010-262025 A

Here, a typical image forming apparatus sometimes includes a plurality of gamma correction tables for character data, photographic data, and the like.
However, in the technique of Patent Document 1, it is necessary to execute calibration for all the gamma correction tables, which increases the waiting time of the user.

  The present invention has been made in view of such a situation, and an object thereof is to provide an image forming apparatus that solves the above-described problems.

An image forming apparatus according to the present invention identifies a storage medium detection unit that detects that a portable storage medium is loaded, and a type of a file stored in the portable storage medium detected by the storage medium detection unit A file type identifying unit, a file content analyzing unit for analyzing the content of the file corresponding to the type of the file identified by the file type identifying unit, the file type, and / or the file content A calibration table determination unit that determines the type of gamma correction table to be calibrated according to the contents of the file analyzed by the analysis unit, and a calibration unit that calibrates the gamma correction table corresponding to the determination of the calibration table determination unit. It is characterized by providing.
The image forming apparatus of the present invention is characterized in that the calibration table determination unit determines to calibrate the raster gamma correction table when the file stored in the portable storage medium is an image file.
In the image forming apparatus of the present invention, the proofreading table determination unit, when the file stored in the portable storage medium is a document file and character drawing data exists, a gamma correction table for text, When the image file exists inside, it is determined that the raster gamma correction table and the vector gamma correction table are calibrated when the vector data object exists.
In the image forming apparatus of the present invention, the calibration unit generates a test patch image corresponding to the gamma correction table to be calibrated on the intermediate transfer belt, and the patch generation unit causes the patch transfer unit to generate a test patch image on the intermediate transfer belt. A patch density measuring unit that measures the density of the generated test patch image; and a correction table setting unit that sets the gamma correction table from the density of the test patch image measured by the patch density measuring unit. It is characterized by.
The image forming method of the present invention is an image forming method executed by an image forming apparatus, and the image forming apparatus detects that a portable storage medium is mounted, and detects the detected portable storage medium. Identify the type of file stored, analyze the content of the file corresponding to the identified file type, and calibrate according to the type of file and / or the analyzed content of the file The type of gamma correction table to be determined is determined, and the gamma correction table corresponding to the determination is calibrated.

  According to the present invention, the time required for calibration is optimized by determining and calibrating the type of gamma correction table to be calibrated based on the type and / or content of the file stored in the portable storage medium. An image forming apparatus capable of reducing the waiting time of the user can be provided.

1 is a system configuration diagram according to an embodiment of an image forming apparatus of the present invention. FIG. 2 is a schematic perspective view of a photosensitive drum, an intermediate transfer belt, and a sensor of the image forming unit of the image forming apparatus shown in FIG. 1. FIG. 2 is a block diagram illustrating a control configuration of the image forming apparatus illustrated in FIG. 1. FIG. 4 is a conceptual diagram of a gamma correction table and a correction table determination table shown in FIG. 3. It is a flowchart of the calibration process which concerns on embodiment of this invention. It is a conceptual diagram of the test patch image of the calibration process shown in FIG.

<Embodiment>
[System Configuration of Image Forming Apparatus 1]
First, the system configuration of the image forming apparatus 1 will be described with reference to FIGS. 1 and 2.

  The image forming apparatus 1 includes an image processing unit 11, a document reading unit 12, a document feeding unit 13, a sheet feeding unit 14, a network transmission / reception unit 15, an operation panel unit 16, an image forming unit 17, a storage unit 19, and the like. Each unit is connected to the control unit 10 and controlled in operation by the control unit 10.

The control unit 10 includes a general purpose processor (GPP), a central processing unit (CPU), a micro processing unit (MPU), a digital signal processor (DSP), a graphics processing unit (GPU), an application specific processor (ASIC). An information processing unit such as a processor for a specific application).
The control unit 10 reads out a control program stored in the ROM or HDD of the storage unit 19, develops the control program in the RAM, and executes it to operate as each unit of a functional block described later. The control unit 10 controls the entire apparatus according to predetermined instruction information input from an external terminal such as a PC (Personal Computer) or a smartphone (not shown) or the operation panel unit 16.

The image processing unit 11 is an information processing unit such as a DSP (Digital Signal Processor) or a GPU (Graphics Processing Unit). The image processing unit 11 is a unit that performs predetermined image processing on image data, and performs various types of image processing such as enlargement / reduction, density adjustment, gradation adjustment, and image improvement.
The image processing unit 11 stores the image read by the document reading unit 12 in the storage unit 19 as an image file. At this time, the image file can be converted into a file 200 (FIG. 3) in various document files and image file formats.

The document reading unit 12 is a (scan) unit that reads a set document. The document reading unit 12 is disposed on the upper part of the main body of the image forming apparatus 1.
The document reading unit 12 includes a scanner, a platen glass, and a document reading slit. When reading a document placed on the platen glass, the document reading unit 12 moves the scanner to a position facing the platen glass and reads the document placed on the platen glass while scanning to obtain image data. The acquired image data is output to the control unit 10.

  In addition, when reading the document fed from the document feeding unit 13, the document reading unit 12 moves the scanner to a position facing the document reading slit. Then, the document reading unit 12 reads the document in synchronization with the document transport operation by the document feeding unit 13 through the document reading slit, and acquires image data. The document reading unit 12 outputs the acquired image data to the control unit 10.

The document feeding unit 13 is a unit that transports a document read by the document reading unit 12. The document feeding unit 13 is disposed on the document reading unit 12.
The document feeder 13 includes a document placement unit and a document transport mechanism. The document feeding unit 13 feeds the documents placed on the document placing unit one by one by the document transport mechanism in order, and feeds them to the document reading unit 12.

  The paper feed unit 14 is a unit that feeds the recording sheets one by one toward the image forming unit 17. The paper feeding unit 14 is provided in the main body unit.

The network transmission / reception unit 15 is a network connection unit including a LAN board, a wireless transceiver, and the like for connecting to an external network such as a LAN, a wireless LAN, a WAN, and a mobile phone network. The network transmission / reception unit 15 transmits / receives data on a data communication line and transmits / receives voice signals on a voice telephone line.
The network transmission / reception unit 15 may be connected to an external terminal.

The operation panel unit 16 includes an input unit such as a button or a touch panel, and a display unit such as an LCD (Liquid Crystal Display) or an organic EL display. Further, the operation panel unit 16 is disposed on the front side of the image forming apparatus 1.
The buttons on the input unit of the operation panel unit 16 are buttons for giving instructions related to the numeric keypad, start, cancel, operation mode switching, and job execution. This operation mode is copying, FAX transmission, scanner, network scanner, or the like. The job also includes types such as printing, transmission, storage, and recording of the selected document. The input unit of the operation panel unit 16 acquires instructions for various jobs of the image forming apparatus 1 by the user. It is also possible to input and change information of each user according to user instructions acquired from the operation panel unit 16.

Further, the operation panel unit 16 may include, for example, a connection unit such as a USB (Universal Serial Bus) terminal for connecting the portable storage medium 2, a memory card reader, or an optical drive. When the portable storage medium 2 is connected, an operation from the operation panel unit 16 enables so-called “direct printing” that forms an image of the file 200 (FIG. 3) stored in the portable storage medium 2.
The portable storage medium 2 is a USB memory, an MMC, an SD card, various flash memories such as a Memory Stick (registered trademark), a compact flash (registered trademark), an optical storage medium, a USB-connected camera, a PC, a smartphone, or an external HDD. Etc.
The portable storage medium 2 can be connected by various wireless connections such as NFC, WiFi, Bluetooth (registered trademark), and UWB. In this case, the portable storage medium 2 may be a smartphone, a mobile PC, a mobile storage, or the like.
The portable storage medium 2 may be a so-called “cloud” storage. In this case, a file to be output by the user may be specified by the operation panel unit 16 and once downloaded to the storage unit 19 by the network transmission / reception unit 15 may be used.

The image forming unit 17 is a unit that forms an image on a recording sheet from data stored in the storage unit 19 and read by the document reading unit 12 or acquired from an external terminal according to a user output instruction.
The image forming unit 17 includes, for example, an exposure unit corresponding to four colors such as magenta (Magenta, M), cyan (Cyan, C), yellow (Yellow, Y), black (BlacK, K, or B), a developing unit, And a fixing unit. For example, the image forming unit 17 records a toner image on a recording sheet by executing an image forming process including charging, exposure, development, transfer, and fixing corresponding to each color.
The image forming unit 17 includes a photosensitive drum 170, an intermediate transfer belt 171 and a sensor 172 as units for performing exposure and development. These detailed configurations will be described later.

The storage unit 19 is a storage unit that uses a semiconductor memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory) or a storage medium such as an HDD (Hard Disk Drive).
Even if the RAM of the storage unit 19 is in a power saving state, the stored contents are held by a function such as self-refresh.
A control program for controlling the operation of the image forming apparatus 1 is stored in the ROM and HDD of the storage unit 19. In addition to this, the storage unit 19 also stores user account settings. The storage unit 19 may include a document box (storage folder) area for each user.
The storage unit 19 may temporarily store the file 200 (FIG. 3).

In the image forming apparatus 1, the control unit 10 and the image processing unit 11 may be integrally formed, such as a CPU with a built-in GPU or a chip-on-module package.
The control unit 10 and the image processing unit 11 may include a RAM, a ROM, a flash memory, and the like.
Further, the image forming apparatus 1 may include a FAX transmission / reception unit that performs facsimile transmission / reception.

The configuration of the photosensitive drum 170, the intermediate transfer belt 171 and the sensor 172 of the image forming unit 17 will be described with reference to FIG.
Specifically, the photoconductive drum 170 of the present embodiment is configured to include photoconductive drums 170C, M, Y, and K corresponding to the respective colors.
The photosensitive drums 170C, M, Y, and K are charged by charging units (not shown) provided around the respective photosensitive drums. Each of the charged photosensitive drums 170C, M, Y, and K is scanned and exposed to a laser beam modulated based on image data on each circumferential surface, and an electrostatic latent image is formed on each circumferential surface. It is formed. The electrostatic latent images formed on the peripheral surfaces of the photoconductive drums 170C, M, Y, and K are developed with toner by a developing unit (not shown) provided around each of the photosensitive drums, thereby forming a toner image. Is done. This toner image is transferred to the intermediate transfer belt 171 and then fixed to the recording paper by a fixing unit (not shown).
The sensor 172 is an optical sensor or the like for optically measuring the reflectance of the surface of the intermediate transfer belt 171 with infrared rays or the like. The sensor 172 can detect the density of each test patch image (hereinafter simply referred to as “patch”) generated on the intermediate transfer belt 171.

[Control Configuration of Image Forming Apparatus 1]
Here, the control configuration of the image forming apparatus 1 will be described with reference to FIGS.
The control unit 10 of the image forming apparatus 1 includes a storage medium detection unit 100, a file type identification unit 110, a file content analysis unit 120, a calibration table determination unit 130, and a calibration unit 140.
The storage unit 19 stores a gamma correction table 300 and a correction table determination table 310.
The portable storage medium 2 stores a file 200.
Further, the image forming unit 17 outputs a signal of the sensor 172 to the control unit 10.

  The storage medium detection unit 100 detects that the portable storage medium 2 is attached to or detached from (attached to or detached from) the connection part of the operation panel unit 16.

  The file type identification unit 110 identifies the type of the file 200 stored in the portable storage medium 2 detected by the storage medium detection unit 100. The file type identification unit 110 can perform this identification, for example, by analyzing the extension of the file 200, the format of the file 200, metadata, or the like.

The file content analysis unit 120 analyzes the content of the file 200 corresponding to the type of the file 200 identified by the file type identification unit 110.
When the file 200 is a document file, the file content analysis unit 120 analyzes the content with a parser or the like, and outputs the content analysis result to the calibration table determination unit 130.

  The calibration table determination unit 130 determines the type of the gamma correction table 300 to be calibrated based on the type of the file 200 and / or the content of the file 200 analyzed by the file content analysis unit 120. Specifically, the calibration table determination unit 130 refers to the correction table determination table 310, for example, and includes a text gamma correction table 301, a raster gamma correction table 302, and a vector gamma correction table included in the gamma correction table 300. For 303, it is determined whether or not to correct.

The calibration unit 140 calibrates the gamma correction table 300 corresponding to the determination of the calibration table determination unit 130.
In the present embodiment, the calibration unit 140 calibrates any one or any combination or all of the text gamma correction table 301, the raster gamma correction table 302, and the vector gamma correction table 303.

The calibration unit 140 includes a patch generation unit 141, a patch density measurement unit 142, and a correction table setting unit 143.
The patch generation unit 141 generates a patch corresponding to the gamma correction table 300 to be calibrated on the intermediate transfer belt 171.
The patch density measurement unit 142 measures the density of the patch generated on the intermediate transfer belt 171 by the patch generation unit 141 using the sensor 172.
The correction table setting unit 143 sets the gamma correction table 300 based on the patch density measured by the patch density measurement unit 142.

The file 200 is an image file captured by a digital camera or the like, a document file created by various applications, or the like. This image file is, for example, bitmap data configured as a set of pixels. The image file may be in various formats such as jpg, BMP, TIFF, GIF, PNG, RAW, and the like. The image file may be data such as a photograph or a picture taken with a camera, for example.
The document file may be a file such as PDF (Portable Document Format), PS (Post Script, registered trademark), PDL (Page Description Language), various word processors, spreadsheets, presentation software, and the like. The document file may be CAD data, bookbinding data, design data, or the like. For this reason, the document file may include font and character (text) data as character drawing data, an image file of various formats, an object represented by vector data, and the like. Further, the document file may include metadata that is not printed. With this metadata, it is also possible to quickly determine the file type.

Referring to FIG. 4, the gamma correction table 300 adjusts the output value for each color of the image forming unit 17 of the image forming apparatus 1 with respect to the input value on the image data after the file 200 is rasterized, for example. This is an input / output characteristic correction table. In the present embodiment, the input value is the brightness or density designation value of each color, and the output value is the amount of toner sprayed.
Specifically, the graph shown in the example of FIG. 4A shows the input / output characteristics in the case of uncorrected, the horizontal axis shows the input value, and the vertical axis shows the density. This is multiplied by any of the gamma correction tables 300 shown in the graph of FIG. In the gamma correction table 300, the horizontal axis represents input values corresponding to input values, and the vertical axis represents output values. And as shown in the graph which shows the result of multiplication of FIG.4 (c), a desired output characteristic is obtained. Also in this graph, the horizontal axis represents the input value and the vertical axis represents the output value.
The gamma correction table 300 is selected and used as shown below according to the type and / or content of the file 200 to be imaged. This makes it possible to perform optimal printing for various data.

Here, in the example of this embodiment, the gamma correction table 300 includes a text gamma correction table 301, a raster gamma correction table 302, and a vector gamma correction table 303.
The text gamma correction table 301 is a table for performing gamma correction on text (character) drawing data.
The raster gamma correction table 302 is a table for performing gamma correction on an image file.
The vector gamma correction table 303 is a table for performing gamma correction on vector (line drawing) data such as objects.

The correction table determination table 310 is used by the calibration table determination unit 130 to determine the type of the gamma correction table 300 to be calibrated based on the type of the file 200 and / or the content of the file 200 analyzed by the file content analysis unit 120. It is a table that is referred to.
According to the example of FIG. 4D, if the file 200 is an image file, it is determined that the raster gamma correction table 302 is to be calibrated as it is. If the type of the file 200 is a document file, it is determined from the content analysis result that if there is character drawing data, the text gamma correction table 301 is to be calibrated. If there is an image file, it is determined that the raster gamma correction table 302 is to be calibrated. If there is vector data such as an object, it is determined that the vector gamma correction table 303 is to be calibrated.

Here, the control unit 10 of the image forming apparatus 1 executes a control program stored in the storage unit 19, whereby a storage medium detection unit 100, a file type identification unit 110, a file content analysis unit 120, a calibration table determination unit. 130 and the calibration unit 140.
Each unit of the image forming apparatus 1 is a hardware resource for executing the image forming method of the present invention.

[Calibration process by image forming apparatus 1]
Next, with reference to FIGS. 5 to 6, a description will be given of calibration processing during direct printing by the image forming apparatus 1 according to the embodiment of the present invention.
In the calibration process of the present embodiment, the portable storage medium 2 is detected, and when an image file stored in the portable storage medium 2 exists, a patch for calibrating the raster gamma correction table 302 is drawn. If the document file exists, the contents of the document file are analyzed, and any one or any combination or all of the gamma correction table 301 for text, the gamma correction table 302 for raster, and the gamma correction table 303 for vector are calibrated. A patch for rendering is drawn, and the gamma correction table 300 that requires calibration is calibrated.
In the calibration processing of the present embodiment, the control unit 10 mainly executes a program stored in the storage unit 19 using hardware resources in cooperation with each unit.
Hereinafter, the details of the calibration processing of the present embodiment will be described step by step with reference to the flowchart of FIG.

(Step S101)
First, the storage medium detection unit 100 performs a storage medium detection process.
The storage medium detection unit 100 detects that the portable storage medium 2 is mounted on the connection part of the operation panel unit 16. The storage medium detection unit 100 performs this detection, for example, by polling at a specific interval of a connection unit such as a USB or a card reader.

(Step S102)
Next, the file type identification unit 110 performs a file type identification process.
The file type identification unit 110 identifies the type of the file 200 stored in the portable storage medium 2 detected by the storage medium detection unit 100.
For example, the file type identification unit 110 mounts the portable storage medium 2 to identify the file system, and lists the files 200 stored from this root directory to at least one directory below the hierarchy. Get recursively. Further, the file type identification unit 110 acquires a list as to whether or not the file 200 is stored for a directory having a fixed name in which a specific file such as a photo or a document is stored.

(Step S103)
Next, the file type identification unit 110 determines whether printing is possible. The file type identification unit 110 determines Yes when any of the files 200 in the acquired list of files 200 can be printed. Here, the file type identification unit 110 is, for example, a printable identifier. If there is even one readable file 200, the file type identification unit 110 determines Yes as the printable file 200. The file type identification unit 110 determines No in other cases, that is, when the portable storage medium 2 cannot be mounted, or when the file 200 that can be mounted but cannot be printed exists in the file system.
In the case of Yes, the file type identification part 110 advances a process to step S104.
If No, the file type identification unit 110 ends the calibration process. At this time, an error message such as “Cannot perform direct printing” may be displayed on the display unit of the operation panel unit 16.

(Step S104)
When there is a printable file 200, the file content analysis unit 120 determines whether the file is a document file. For example, the file content analysis unit 120 identifies the type based on the identifier of the file 200 stored in the portable storage medium 2, and determines Yes if the file is a document file. The file content analysis unit 120 determines “No” in other cases, that is, when it is an image file.
In the case of Yes, the file content analysis part 120 advances a process to step S105.
In No, the file content analysis part 120 advances a process to step S106.

(Step S105)
When the file 200 is a document file, the file content analysis unit 120 performs content analysis processing.
The file content analysis unit 120 analyzes the content of the file 200 that is a document file by a parser or the like. The file content analysis unit 120 temporarily stores the content analysis result in the storage unit 19.

(Step S106)
Here, the calibration table determination unit 130 performs a calibration table determination process.
The calibration table determination unit 130 refers to the correction table determination table 310 and determines the gamma correction table 300 to be calibrated based on the type and / or content analysis result of the file 200 determined by the identifier of the file 200 or the like. As a result, it is possible to identify the gamma correction table 300 that requires calibration.
Specifically, the calibration table determination unit 130 determines to calibrate the raster gamma correction table 302 when the file 200 stored in the portable storage medium 2 is an image file, for example.
Further, the calibration table determination unit 130, for example, if the file 200 stored in the portable storage medium 2 is a document file and character drawing data exists, the text gamma correction table 301 and the image file are stored. If it exists inside, the raster gamma correction table 302, and if the vector data object exists, it is determined to calibrate any one or any combination or all of the vector gamma correction table 303.
The calibration table determination unit 130 temporarily stores the determination result of the gamma correction table 300 to be calibrated in the storage unit 19.

(Step S107)
Next, the calibration unit 140 performs calibration processing.
Corresponding to the determination result determined by the calibration table determination unit 130, the calibration unit 140 is one of the text gamma correction table 301, the raster gamma correction table 302, and the vector gamma correction table 303, any combination, or Everything is calibrated in a specific order.

According to FIG. 6, specifically, the patch generation unit 141 generates a patch corresponding to the gamma correction table 300 to be calibrated on the intermediate transfer belt 171. This patch is drawn, for example, as a collection of square bars corresponding to specific level input values corresponding to any of the gamma correction tables 300. Specifically, for example, the patch generation unit 141 generates a patch image in the same manner as in normal image formation, exposes and develops a toner image on one of the photosensitive drums 170, and applies it to the intermediate transfer belt 171. A patch is generated by transferring.
The patch density measurement unit 142 measures the density of the patch on the intermediate transfer belt 171 generated by the patch generation unit 141 by the sensor 172. For example, the patch density measurement unit 142 measures the density of a patch bar and calculates a density curve.
The correction table setting unit 143 sets a gamma correction table 300 that is calibrated based on the patch density measured by the patch density measuring unit. At this time, the correction table setting unit 143 can generate and set the corresponding gamma correction table 300 using, for example, the density curve calculated corresponding to the density of each bar.
Thus, the calibration process according to the embodiment of the present invention is completed.

With the configuration described above, the following effects can be obtained.
Even in the technique of Patent Document 1, although calibration is performed at the timing when the portable storage medium 2 is mounted, there is no mention of which table is updated for the gamma correction table 300 to be calibrated.
As another typical technique, for example, a technique for automatically starting calibration when a user inputs a print job from a terminal has been known. In this case, it takes several tens of seconds to several minutes from the start of calibration after the user selects the image forming apparatus as the input destination to the completion of the calibration.
Such a typical image forming apparatus includes a gamma correction table 300 corresponding to a plurality of document types. For this reason, in any typical technique, since all the gamma correction tables 300 are calibrated, the waiting time of the user is long.
On the other hand, in the image forming apparatus 1 according to the embodiment of the present invention, the storage medium detection unit 100 that detects that the portable storage medium 2 is attached / detached, and the storage medium detection unit 100 can detect this. A file type identifying unit 110 for identifying the type of the file 200 stored in the portable storage medium 2 and a file content for analyzing the content of the file 200 corresponding to the type of the file 200 identified by the file type identifying unit 110 The calibration table determination unit 130 that determines the type of the gamma correction table 300 to be calibrated based on the analysis unit 120, the type of the file 200, and / or the content of the file 200 analyzed by the file content analysis unit 120, and the calibration table Calibration of any, any combination, or all of the gamma correction tables 300 corresponding to the determination of the determination unit 130 Characterized in that it comprises a calibration unit 140 that.
With this configuration, only the necessary gamma correction table 300 can be calibrated by analyzing the type and / or contents of the print file 200 in direct printing using the portable storage medium 2. Thereby, it is possible to reduce the printing waiting time of the user generated by the calibration.

In the image forming apparatus 1 according to the embodiment of the present invention, the calibration table determination unit 130 calibrates the raster gamma correction table 302 when the file 200 stored in the portable storage medium 2 is an image file. Then, it is determined that it is determined.
With this configuration, for example, in the case of only an image file such as TIFF or jpg, only the raster gamma correction table 302 needs to be calibrated, so that it is possible to reduce the printing waiting time of the user.

Further, in the image forming apparatus 1 according to the embodiment of the present invention, the calibration table determination unit 130 determines that the file 200 stored in the portable storage medium 2 is a document file and character drawing data exists. Is determined to calibrate the gamma correction table for raster 301, the raster gamma correction table 302 if the image file exists inside, or the vector gamma correction table 303 if the vector data object exists. And
By configuring in this way, it is only necessary to calibrate only the necessary gamma correction table 300 depending on whether it is a text file, a drawing of an object or the like, or an image such as a photograph, even if it is a document file. It becomes possible to reduce the printing waiting time of the user.

Further, in the image forming apparatus 1 according to the embodiment of the present invention, the calibration unit 140 generates a test patch image corresponding to the gamma correction table 300 to be calibrated on the intermediate transfer belt 171 and the patch. A patch density measuring unit 142 that measures the density of the patch image generated on the intermediate transfer belt 171 by the generating unit 141, and a correction table setting that sets the gamma correction table 300 from the patch density measured by the patch density measuring unit 142. Part 143.
With this configuration, the gamma correction table 300 to be calibrated can be calibrated in order.

[Other Embodiments]
In the above-described embodiment, when a plurality of files 200 are stored in the portable storage medium 2, it is described that the types and contents of all the files 200 are analyzed, but the present invention is not limited to this.
For example, the type may be determined only for the file 200 designated by the user, and the content may be analyzed.
With this configuration, when the user instructs to output only a specific type of file 200 such as a photo or document on the flash memory card, only the corresponding gamma correction table 300 can be calibrated. This increases the possibility of reducing the printing waiting time of the user. It is also possible to improve the accuracy of calibration by calibrating immediately before printing.

  The present invention can also be applied to an information processing apparatus other than the image forming apparatus. That is, a configuration using a network scanner, a server in which the scanner is separately connected by a USB, or the like may be used.

  Further, the configuration and operation of the above-described embodiment are examples, and it goes without saying that they can be appropriately modified and executed without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Portable storage medium 10 Control part 11 Image processing part 12 Original reading part 13 Original feeding part 14 Paper feeding part 15 Network transmission / reception part 16 Operation panel part 17 Image forming part 19 Storage part 100 Storage medium detection part 110 File type identification unit 120 File content analysis unit 130 Calibration table determination unit 140 Calibration unit 141 Patch generation unit 142 Patch density measurement unit 143 Correction table setting units 170, 170C, 170M, 170Y, 170K Photosensitive drum 171 Intermediate transfer belt 172 Sensor 200 File 300 Gamma correction table 301 Gamma correction table for text 302 Gamma correction table for raster 303 Gamma correction table for vector 310 Correction table determination table

Claims (5)

A storage medium detector for detecting that a portable storage medium is mounted;
A file type identification unit for identifying the type of file stored in the portable storage medium detected by the storage medium detection unit;
Corresponding to the file type identified by the file type identification unit, a file content analysis unit that analyzes the content of the file;
A calibration table determination unit that determines the type of the gamma correction table to be calibrated according to the file type and / or the file content analyzed by the file content analysis unit;
An image forming apparatus comprising: a calibration unit that calibrates the gamma correction table corresponding to the determination of the calibration table determination unit. The calibration table determination unit includes:
The image forming apparatus according to claim 1, wherein when the file stored in the portable storage medium is an image file, it is determined to calibrate a raster gamma correction table. The calibration table determination unit includes:
The file stored in the portable storage medium is a document file;
If character drawing data exists, the text gamma correction table,
If the image file exists inside, the raster gamma correction table,
The image forming apparatus according to claim 2, wherein when there is an object of vector data, it is determined that the vector gamma correction table is calibrated. The calibration unit is
A patch generation unit that generates on the intermediate transfer belt a test patch image corresponding to the gamma correction table to be calibrated;
A patch density measurement unit that measures the density of the test patch image generated on the intermediate transfer belt by the patch generation unit;
The image according to claim 1, further comprising: a correction table setting unit that sets the gamma correction table from the density of the test patch image measured by the patch density measurement unit. Forming equipment. An image forming method executed by an image forming apparatus, wherein the image forming apparatus includes:
Detect that a portable storage medium is installed,
Identify the type of file stored in the detected portable storage medium,
Corresponding to the identified file type, analyze the contents of the file,
According to the type of the file and / or the content of the analyzed file, the type of the gamma correction table to be calibrated is determined,
An image forming method comprising calibrating the gamma correction table corresponding to the determination.

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