JP2006277267A - Image data cache device, printer, and image data cache method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To rapidly acquire image data not stored in a plurality of image buffers. <P>SOLUTION: A plurality of image buffers 61 of the image data cache device store a plurality of partial image data obtained by dividing image data to be printed in a predetermined size unit. A presence information storage means 45 stores presence information showing, for each partial image data, whether the partial image data is stored in any one of the image buffers 61 or not. A determination means 44 determines, when image data to be printed is requested, whether partial image data containing the image data related to the request is stored in any one of the image buffers 61 or not in reference to the presence information corresponding to this partial image data. When the partial image data containing the image data related to the request is not stored in any one of the image buffers 61, an acquisition means 44 acquires and stores this partial image data from a predetermined acquisition destination in any one of the image buffers 61, and also updates the presence information corresponding thereto. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image data cache device, a printing device, and an image data cache method.

  Patent Documents 1 and 2 disclose a printing system. In these conventional printing systems, a digital camera and a printer are connected by a USB (Universal Serial Bus) cable. In this conventional printing system, the camera generates a print request for the printer in response to an operation on the button, and the printer reads image data necessary for the printing process from the camera based on the request, An image is printed based on the image data.

JP 2003-259274 A (drawings, detailed description of the invention) JP 2002-56676 A (drawings, detailed description of the invention)

  In these conventional printing systems, a printer reads image data of an image to be printed from a camera and prints it. A USB cable is used to read this image data. The speed of data communication between such devices is generally slower than the speed of data exchange within the same device.

  Therefore, for example, an image buffer array is provided in the printer, and image data is stored in the image buffer as appropriate. Thereafter, image data necessary for printing is supplied from the image buffer, so that the image data is stored. It is conceivable to shorten the time from when it is necessary until the image data is acquired, and as a result, to shorten the printing time.

  However, there are cases where the effect of shortening the printing time due to the provision of such a plurality of image buffers cannot be sufficiently obtained. For example, when image data is required for printing, the printer determines whether the image data is stored in order from the top of the image buffer array. In this case, when the image data is stored in the last image buffer, the printer may determine that the data is stored in the image buffer unless the plurality of image buffers are examined from the top to the end. Can not. As a result, although there is image data in the image buffer, it takes time to obtain the image data after the image data is needed, and the printing time is not effectively shortened.

  An object of the present invention is to provide an image data cache device, a printing device, and an image data cache method that can quickly acquire image data when no image is stored in an image buffer.

  An image data cache device according to the present invention includes a plurality of image buffers each storing one of a plurality of partial image data obtained by dividing image data to be printed in a predetermined size unit, and partial image data for each partial image data. Presence / absence information storage means for storing presence / absence information indicating whether or not image data is stored in any of the image buffers, and image data related to the request when there is a request for any image data in the image data to be printed A determination means for determining whether or not partial image data including the requested image data is stored in the image buffer with reference to presence / absence information corresponding to the partial image data including the portion, and a portion including the requested image data If the determining means determines that the image data is not stored in any image buffer, the image data related to the request is included. Acquires partial image data from the predetermined acquisition destination causes are stored in the image buffer and acquiring means for updating the presence information corresponding to the partial image data, and has a.

  By adopting this configuration, when the image data requested by the image processing means is not stored in the image buffer of the image data cache device, it is determined efficiently and the image data relating to the request is acquired. be able to.

  In the image data cache device according to the present invention, in addition to each configuration of the above-described invention, the presence / absence information storage means has 1-bit data as the number of partial image data as presence / absence information, A bit arrangement associated with 1-bit data is stored.

  If this configuration is adopted, the determination unit can easily specify the bit corresponding to the requested image data based on the order.

  In the image data cache device according to the present invention, in addition to each configuration of the above-described invention, the bit arrangement is associated with each partial image data in the same order as the partial image data in the image data to be printed. It has 1-bit data as presence / absence information.

  If this configuration is adopted, the determination unit can easily specify the bit corresponding to the requested image data based on the order.

  In the image data cache device according to the present invention, in addition to the components of the above-described invention, the acquisition unit acquires partial image data including the requested image data from a predetermined acquisition destination, and overwrites and stores it in the image buffer. In this case, the presence / absence information corresponding to the partial image data erased by overwriting the image buffer is updated.

  If this configuration is adopted, a plurality of image buffers having a total storage capacity smaller than that of image data to be printed can be used.

  The image data cache apparatus according to the present invention is only requested when the determination unit determines that the partial image data including the requested image data is stored in the image buffer, in addition to the above-described configurations of the invention. The image processing apparatus includes a supply unit that retrieves the image data in the image buffer, reads out the requested image data from the image buffer, and supplies the image data to the request source.

  By adopting this configuration, it is possible to prevent the image buffer from being searched unnecessarily when the partial image data including the requested image data is not stored in the image buffer.

  In the image data cache device according to the present invention, in addition to the components of the above-described invention, the acquisition unit transmits partial image data including the requested image data from a digital camera, a card reader, a semiconductor memory, a portable terminal, or a computer. To get.

  By adopting this configuration, it is possible to efficiently print image data stored in a digital camera, card reader, semiconductor memory, portable terminal or computer.

  The printing apparatus according to the present invention supplies the image data requested to be acquired to the request source, the image data cache apparatus of each configuration according to the above-described invention, and the image data of the image to be printed on the image data cache apparatus. An image processing unit that requests acquisition and generates print control data using image data supplied in response thereto, and a printing unit that executes printing based on the print control data.

  By adopting this configuration, when the image data requested by the image processing means is not stored in the image buffer of the image data cache device, it is judged efficiently and the image data related to the request is acquired. Can be printed.

  The image data caching method according to the present invention determines whether or not partial image data is stored in any of the image buffers for each partial image data when there is a request for any image data in the image data to be printed. The presence / absence information corresponding to the partial image data including the image data related to the request is read from the predetermined presence / absence information storage means for storing the presence / absence information indicating whether or not the image buffer is requested according to the read presence / absence information. A step of determining whether or not partial image data including such image data is stored, and a determination unit determining that the partial image data including the requested image data is not stored in any of the image buffers When the partial image data including the image data related to the request is acquired from a predetermined acquisition destination and stored in the image buffer And updating the presence information corresponding to the partial image data to, and has a.

  If this method is adopted, the image data relating to the request is stored in the plurality of image buffers without searching whether or not the image data relating to the request is stored one by one for all of the plurality of image buffers. It is possible to determine that the request has not been made and to quickly obtain the image data relating to the request.

  Hereinafter, an image data cache device, a printing device, and an image data cache method according to embodiments of the present invention will be described with reference to the drawings. The printing apparatus will be described using a printer that acquires image data used for printing from a digital still camera (DSC) as an example. The image data cache device will be described as a part of the printer. The image data cache method will be described as part of the operation of the printer.

  FIG. 1 is a diagram showing a printer 1 as a printing apparatus according to an embodiment of the present invention and a DSC 2 as an acquisition destination of image data connected to the printer 1. The DSC 2 and the printer 1 are connected by a USB cable 3. A system that directly connects the DSC 2 and the printer 1 in this way is a type of direct printing system. The DSC 2 and the printer 1 may be connected to other cables other than the USB cable 3, such as a dedicated cable for a printer, a wireless communication line, or the like.

  FIG. 2 is a block diagram illustrating a configuration when the DSC 2 is operating in the imaging mode. The DSC 2 includes a CCD (Charge Coupled Device) camera 51 that outputs imaging data, a liquid crystal monitor 11 that displays images, an input device 12 that has imaging buttons and selection buttons (not shown), an image data generation unit 52, and the like. A storage processing unit 53 and a semiconductor memory 13. The semiconductor memory 13 is formed in a card shape such as a flash memory, for example, and is detachable from a housing not shown of the DSC 2.

  The image data generation unit 52 generates EXIF image data using the imaging data output from the CCD camera 51 when the imaging button of the input device 12 is operated.

  FIG. 3 is an explanatory diagram for explaining processing for generating EXIF image data by the image data generating unit 52. FIG. 3A is an image based on imaging data output from the CCD camera 51. The image based on the imaging data is a horizontally long image, and a single house is captured.

  The image data generation unit 52 encodes the imaging data of the image shown in FIG. 3A in units of blocks delimited by dotted lines in the figure, and the encoded data is converted as shown in FIG. Generate intermediate data arranged in encoding order. One block is 8 × 8 pixels as shown in FIG. In the image of FIG. 3, the image data generation unit 52 divides the image based on the imaging data into 60 blocks of 6 rows and 10 columns and encodes each block.

  After encoding in block units, the image data generation unit 52 compresses the encoded intermediate data at a predetermined compression rate. Specifically, the image data generation unit 52 uses the data amount in the intermediate data in FIG. 3B before compression as a reference so that the total data amount after compression becomes a data amount with a predetermined compression rate. The intermediate data is compressed by thinning out the component data that has little effect on the data.

  After compressing the intermediate data, the image data generation unit 52 generates EXIF image data included as the compressed image data, as shown in FIG. The EXIF image data includes header data, compressed intermediate data image data, and EOF (End Of File) data. In the header data, for example, information such as the size of the image data (the number of pixels in the vertical direction and the number of pixels in the horizontal direction of the image in FIG. 3A) is converted into information as necessary. The EXIF image data includes image data compressed by JPEG (Joint Photographic Coding Experts Group).

  In the intermediate data in FIG. 3B and the EXIF image data in FIG. 3C, the size of each square indicates the data amount of each block. In the intermediate data, the data amount of each block is equal so that the size of the square of each block is equal in FIG. On the other hand, when the compression is performed by the JPEG method so that the square size of the block 3 and the square size of the block 4 in FIG. 3C are different, the data amount of each block is different for each block.

  Returning to FIG. 2, the image data generation unit 52 supplies the generated EXIF image data to the storage processing unit 53. The storage processing unit 53 stores the supplied EXIF image data in the semiconductor memory 13 as the EXIF image file 21.

  The semiconductor memory 13 has a data storage area 22 for storing data such as the EXIF image file 21 and a memory management area 23. The semiconductor memory 13 manages stored data using a file system such as a FAT (File Allocation Table) 16 or a FAT 32, for example. In the memory management area 23, the file name, file size, storage position information in the data storage area 22, etc. stored in the data storage area 22 are stored.

  The image data generation unit 52 stores the EXIF image file 21 in the data storage area 22. Further, the save processing unit 53 saves the file name, file size, and save position information in the data storage area 22 of the saved EXIF image file 21 in the memory management area 23. As a result, the EXIF image file 21 having the image data of the image captured by the DSC 2 is stored in the semiconductor memory 13.

  Returning to FIG. 1, during direct printing, the DSC 2 includes a communication I / F 16 having a USB communication I / F (Interface) 14 and a USB mass storage class 15 in addition to the liquid crystal monitor 11, the input device 12, and the semiconductor memory 13. A print instruction unit 17 and an image data transmission unit 18 are provided. A plurality of EXIF image files 21 are stored in the semiconductor memory 13. The USB mass storage class 15, the print instruction unit 17, and the image data transmission unit 18 are stored in a USB mass storage class program stored in a storage device of the DSC 2 (not shown) by a CPU (Central Processing Unit) of the DSC 2. This is realized by executing a print instruction program and an image data transmission program.

  The USB communication I / F 14 has a USB connector (not shown). A USB cable 3 is connected to the USB connector. When a signal is input from the USB connector, the USB communication I / F 14 extracts data from the signal. The USB communication I / F 14 generates a signal based on the data to be transmitted, and outputs this signal to the USB connector.

  The USB mass storage class 15 is a communication processing unit that transmits and receives data between the host and the device using the USB communication I / F 14. The USB mass storage class 15 uses a SCSI (Small Computer System Interface) subclass as its subclass.

  The DSC 2 communication I / F 16 having the USB communication I / F 14 and the USB mass storage class 15 transmits data supplied from the print instruction unit 17 and the image data transmission unit 18 to the printer 1 via the USB cable 3. . The communication I / F 16 of the DSC 2 supplies data received from the printer 1 via the USB cable 3 to the print instruction unit 17 and the image data transmission unit 18.

  The print instruction unit 17 selects an image to be printed, generates a print instruction for causing the printer 1 to print the image, and supplies the print instruction to the communication I / F 16 of the DSC 2.

  The image data transmission unit 18 reads the image data requested to be transmitted from the semiconductor memory 13 and supplies it to the communication I / F 16 of the DSC 2.

  The printer 1 has, as a printing mechanism for printing on a paper medium 30 or the like, a feed roller 31 that feeds the medium 30, a feed motor 32 that rotationally drives the feed roller 31, a carriage 33, and a carriage 33 that feeds the carriage 33. And a carriage motor 34 that reciprocates along the axial direction of 31. A predetermined number of cartridges such as yellow, magenta, cyan, and black are detachably attached to the carriage 33. An ink ejection head (not shown) is formed at a portion of the carriage 33 on the platen side (not shown). Many ink jet nozzles (not shown) are opened in the ink discharge head. Piezo elements (not shown) are arranged inside each inkjet nozzle. A piezo element is an element that deforms according to the voltage applied to it. When the piezoelectric element is deformed by the voltage, an amount of ink corresponding to the deformation amount is ejected from the inkjet nozzle.

  In addition, the printer 1 includes a communication I / F 38 having a USB communication I / F 36 and a USB mass storage class 37, a print instruction interpretation unit 39, an image processing unit 40 as an image processing unit, and an image processing memory 41. A control unit 42 as a printing unit, an image buffer memory 43, an image buffer management unit 44 as a determination unit, an acquisition unit and a supply unit, and an image buffer management memory 45 as a presence / absence information storage unit.

  The communication I / F 38 of the printer 1 supplies the data received from the communication I / F 16 of the DSC 2 via the USB cable 3 to the print instruction interpretation unit 39 or the image buffer management unit 44. The communication I / F 38 of the printer 1 transmits the data supplied from the print instruction interpretation unit 39 or the image buffer management unit 44 to the communication I / F 16 of the DSC 2 via the USB cable 3.

  The print instruction interpretation unit 39 interprets the print instruction, generates an internal instruction based on the interpretation, and supplies the internal instruction to the image processing unit 40. The print instruction interpretation unit 39 instructs the image buffer management unit 44 to start printing.

  The image processing unit 40 acquires image data of an image to be printed based on an internal instruction, and generates print control data using the acquired image data. The image processing unit 40 temporarily stores, for example, image processing parameters generated during the processing in the image processing memory 41 and uses them when generating print control data. The image processing unit 40 supplies the generated print control data to the control unit 42.

  The control unit 42 outputs control signals to the feed motor 32 and the carriage motor 34 based on the print control data, and applies voltages to the plurality of piezoelectric elements of the carriage 33. As a result, the control unit 42 executes printing based on the print control data.

  FIG. 4 is a diagram showing a memory structure of the image buffer memory 43 and the image buffer management memory 45.

  The image buffer memory 43 is a memory having a storage capacity of, for example, several to several tens of megabytes, and has n image buffers 61 (n is an integer of 1 or more) having a predetermined storage capacity. Hereinafter, in order to distinguish the plurality of image buffers 61 from each other, the first image buffer 61, the second image buffer 61,... In order from the top image buffer memory 43 illustrated at the top of FIG. This is described as an nth image buffer 61. The plurality of image buffers 61 are associated with index numbers from 0 to (n−1) in order from the top of FIG.

  Each image buffer 61 has a storage capacity of, for example, about several to several tens of kilobytes, and stores image data acquired from the DSC 2. In each image buffer 61, image data is stored in units divided from the head of the image buffer 61 for each storage capacity of the image buffer 61. Hereinafter, each piece of image data in this unit is referred to as partial image data. For example, when the storage capacity of one image buffer 61 is 2 kilobytes, the first image buffer 61 stores partial image data from the top of the image data to the second kilobyte, and the second image buffer 61 stores partial image data from the next data of the second kilobyte of the image data to the previous one of the fourth kilobyte. Note that the storage capacity of the image buffer 61 is larger than the amount of data that is once requested by the image processing unit 40 to the image buffer management unit 44, as will be described later. For example, when the image buffer 61 of 3 kilobytes is provided in the image buffer memory 43 of 5 megabytes, the number of the image buffers 61 is about 1666 (= n).

  The image buffer management memory 45 is a memory having a storage capacity of several megabytes, and has the same number of offset data 62 as the number (n) of the image buffers 61. Note that the image buffer memory 43 and the image buffer management memory 45 may be formed in the same memory element. Hereinafter, in order to distinguish the plurality of offset data 62 from each other, the first offset data 62, the second offset data 62,... In order from the top image buffer management memory 45 illustrated at the top of FIG. , Described as nth offset data 62. The plurality of offset data 62 are associated with index numbers from 0 to (n−1) in order from the top of FIG.

  Each offset data 62 is used in pairs with each image buffer 61 to which the same index number can be associated. Each offset data 62 stores storage position information of the partial image data stored in the image buffer 61 associated with the same index number at the acquisition destination (here, the data storage area 22 of the semiconductor memory 13). The The storage position information has a data size of 4 bytes, for example, and stores an offset value indicating the data position from the head of the image data of the head data of the partial image data stored in the image buffer 61.

  Further, each offset data 62 is stored in association with storage time data 63. The storage time data 63 stores time information related to the partial image data stored in the image buffer 61 such as the time when the partial image data is stored in the image buffer 61 and the time when the partial image data is acquired.

  Further, the image buffer management memory 45 has bitmap data 64 as presence / absence information. The bitmap data 64 has the same number of bits as the number of data corresponding to the maximum size of image data that can be printed by the printer 1 divided by one storage capacity of the image buffer 61 (that is, the size of partial image data). A bit array having a number. For example, if 32 partial image data are obtained from the beginning to the end of the EXIF image file 21, the bitmap data 64 may be 32 bits.

  In the plurality of image buffers 61, image data to be printed is stored in units divided from the top of the image buffer 61 for each storage capacity of the image buffer 61. Each bit of the bitmap data 64 corresponds to each partial image data on a one-to-one basis and in the same order as the order of the partial image data in the image data to be printed. The first bit of the bitmap data 64 corresponds to the first partial image data of the image data to be printed (image data in the EXIF image file 21).

  The value of each bit is “1” indicating that there is partial image data corresponding to the bit being read into any of the plurality of image buffers 61, and is read into any of the plurality of image buffers 61. If not, “0” means none. In the bitmap data 64, the number of bits that are simultaneously “1” is the maximum number of the image buffers 61.

  The image buffer management unit 44 manages a plurality of image buffers 61, a plurality of offset data 62, and the like, reads requested image data from the image buffer 61, and supplies the requested image data to a request source. The image buffer management unit 44 also acquires partial image data not stored in the plurality of image buffers 61 from the DSC 2, stores it in the image buffer 61, and supplies it to the request source.

  Next, the operation of the direct printing system having the above configuration will be described.

  When the DSC 2 and the printer 1 are connected by the USB cable 3, the USB mass storage class 15 of the DSC 2 and the USB mass storage class 37 of the printer 1 communicate with each other. As a result, endpoints used by the USB mass storage classes 15 and 37 for bulk transfer of data are generated, and the DSC 2 and the printer 1 can exchange data with each other.

  The print instruction unit 17 of the DSC 2 selects an image file to be printed from the EXIF image files 21 stored in the semiconductor memory 13. Specifically, the print instruction unit 17 reads data such as the file name of the EXIF image file 21 from the semiconductor memory 13 and displays the file name on the liquid crystal monitor 11. The print instruction unit 17 selects an EXIF image file 21 to be printed based on input data output from the input device 12 in response to a user operation.

  After selecting an image file to be printed, the print instruction unit 17 selects a print condition. Specifically, the print instruction unit 17 causes the liquid crystal monitor 11 to display a print condition selection screen. The printing conditions include, for example, the size of the medium 30 to be printed such as A4 and L plates, the type of the medium 30 such as plain paper and glossy paper, and the layout of the image to be printed on one medium 30 such as 1up and 2up. There is. The print instruction unit 17 selects a print condition based on input data output from the input device 12 in response to a user operation.

  Thereafter, the print instruction unit 17 generates a print instruction for printing the image under the print conditions, and supplies the print instruction to the communication I / F 16 of the DSC 2. For example, when an image is printed on L-size glossy paper at 1 up, the print instruction includes a file name of the image to be printed, printing conditions for designating L-size glossy paper as the medium 30, and the entire surface of the medium 30. Includes printing conditions for printing one image. In the print instruction, instead of the file name, a file ID (identification) issued in a one-to-one correspondence may be used for each EXIF image file 21 stored in the semiconductor memory 13.

  The communication I / F 16 of the DSC 2 transmits the supplied print instruction to the communication I / F 38 of the printer 1 via the USB cable 3. The communication I / F 38 supplies the received print instruction to the print instruction interpretation unit 39.

  In the USB specification, one of a plurality of devices connected by the USB cable 3 functions as a USB host, and the other functions as a USB device. The DSC 2 is manufactured on the premise that it is connected to a computer functioning as a USB host by the USB cable 3, and thus generally functions as a USB device. The printer 1 directly connected to the DSC 2 functions as a USB host. In this case, the communication I / F 16 of the DSC 2 transmits the supplied print instruction to the communication I / F 38 of the printer 1 based on, for example, periodic print instruction acquisition processing by the communication I / F 38 of the printer 1. What should I do?

  The print instruction interpreting unit 39 interprets the supplied print instruction, generates an internal instruction for executing printing designated by the print instruction, and supplies the internal instruction to the image processing unit 40. For example, if the print instruction includes a file name of an image to be printed, a print condition for designating L glossy paper, and a print condition for printing one image on the entire surface of the medium 30, the print instruction The interpretation unit 39 performs an APF (Auto Photo Fine) process, which is a kind of image correction, on the image data of the file name, and then generates an internal instruction to print on the entire surface of the L glossy paper with high quality. To the image processing unit 40.

  When an internal instruction for printing is supplied, the image processing unit 40 starts generating print control data in accordance with the internal instruction. The image processing unit 40 requests the image buffer management unit 44 for image data. In this image data request, the image processing unit 40 designates, for example, a file name of image data to be printed and a range of requested image data. The range of requested image data is specified by, for example, the offset value (for example, the number of kilobytes from the beginning) of the first data in the range and the requested data amount. The amount of data is, for example, 512 bytes.

  The print instruction interpretation unit 39 supplies an internal instruction to the image processing unit 40 and instructs the image buffer management unit 44 to start printing.

  FIG. 5 is a flowchart showing the operation of the image buffer management unit 44.

  When instructed to start printing (step ST1), the image buffer management unit 44 performs an initial setting process (step ST2). The image buffer management unit 44 initializes the plurality of image buffers 61, clears the plurality of offset data 62 and the storage time data 63, sets all the bit values of the bitmap data 64 to “0”, and sets them as control pointer variables. Substitute the initial value “0”. Thereafter, the image buffer management unit 44 waits for a request for image data (step ST3).

  As described above, when the image processing unit 40 requests the image data by specifying the file name of the image data to be printed and the range of the requested image data, the image buffer management unit 44 firstly requests the requested range. Is divided by one storage capacity of the image buffer 61. The image buffer management unit 44 specifies the bit in the order corresponding to the value of the quotient (however, the integer part thereof) counted from the head of the bitmap data 64 as the bit corresponding to the requested image data (step). ST4). The image buffer management unit 44 reads the specified bit value from the bitmap data 64, and determines whether or not the read bit value is “1” (step ST5).

  When the partial image data corresponding to the identified bit is not read into the plurality of image buffers 61, the value of the bit corresponding to the partial image data is “0”. When determining that the value of the read bit is not “1”, the image buffer management unit 44 acquires partial image data corresponding to the bit from the DSC 2 (step ST6).

  Specifically, the image buffer management unit 44 generates a transmission instruction for causing the DSC 2 to transmit the partial image data stored in the semiconductor memory 13 of the DSC 2. The image buffer management unit 44 generates a transmission instruction that instructs transmission of partial image data including the image data requested by the image processing unit 40.

  FIG. 6 is a diagram illustrating a relationship between image data requested by the image processing unit 40 to the image buffer management unit 44 and partial image data acquired by the image buffer management unit 44 from the DSC 2. As shown in FIG. 6, when the image processing unit 40 specifies an offset value having data in the middle of the third block of the image data as the head data, and requests image data up to the middle of the fourth block, The image buffer management unit 44 includes the image data related to the request, and the range in which the image data to be printed is divided from the head data for each data amount corresponding to the storage capacity of one image buffer 61 (in FIG. Requests transmission of partial image data in the second range from the top of the data.

  In this embodiment, since the USB mass storage classes 37 and 15 are used, the semiconductor memory 13 of the DSC 2 is recognized as one storage when viewed from the printer 1 side. For this reason, the image buffer management unit 44 of the printer 1 first acquires the information in the memory management area 23 of the semiconductor memory 13 of the DSC 2 from the image data transmission unit 18 of the DSC 2 and stores the semiconductor memory 13 of the image data instructing transmission. The storage location in the data storage area 22 is specified. Next, the image buffer management unit 44 generates an instruction to transmit image data stored in the specified storage location.

  The image buffer management unit 44 supplies a transmission instruction for the generated partial image data to the communication I / F 38 of the printer 1. The communication I / F 38 of the printer 1 transmits a transmission instruction for the supplied partial image data to the communication I / F 16 of the DSC 2. The communication I / F 16 of the DSC 2 supplies a transmission instruction for the received partial image data to the image data transmission unit 18. The image data transmission unit 18 reads the image data instructed to be transmitted from the semiconductor memory 13 and supplies it to the communication I / F 16 of the DSC 2. The communication I / F 16 of the DSC 2 transmits the supplied image data to the communication I / F 38 of the printer 1. The communication I / F 38 of the printer 1 supplies the received image data to the image buffer management unit 44. Thereby, the image buffer management unit 44 acquires partial image data instructed to be transmitted.

  When the image buffer management unit 44 acquires the partial image data instructed to be transmitted, the image buffer management unit 44 saves the partial image data acquired from the DSC 2 in the empty image buffer 61 that does not store the partial image data. If there is no free image buffer 61, the image buffer management unit 44 overwrites the partial image data acquired from the DSC 2 on the image buffer 61 corresponding to the offset data 62 having the oldest storage time in the image buffer management memory 45. (Step ST7).

  Further, the image buffer management unit 44 stores the offset value of the first data of the partial image data acquired from DSC 2 in the offset data 62 corresponding to the image buffer 61 that stores the partial image data acquired from DSC 2, and the offset data The time of the storage time data 63 corresponding to 62 is updated to the current time.

  Further, the image buffer management unit 44 updates the value of the bit specified earlier in the bitmap data 64 to “present (1)”. When there is no empty image buffer 61 and the image buffer 61 is overwritten, the image buffer management unit 44 updates the value of the bit corresponding to the partial image data erased by the overwriting to “none (0)” ( Step ST8). The image buffer management unit 44 updates the value of the control pointer variable to the index number of the updated offset data 62 (step ST9).

  After storing the partial image data acquired from the DSC 2 in the specified image buffer 61, the image buffer management unit 44 extracts the image data requested by the image processing unit 40 from the partial image data acquired from the DSC 2. The image is supplied to the image processing unit 40 (step ST10). Thereafter, the image buffer management unit 44 returns to a state waiting for a request for image data (step ST3).

  On the other hand, when the partial image data corresponding to the specified bit is stored in any of the plurality of image buffers 61, the value of the bit read from the bitmap data 64 by the image buffer management unit 44 is “1”. In this case, the image buffer management unit 44 determines that the value of the identified bit is “1” in step ST <b> 5, and starts a search process of the image buffer management memory 45.

  In the search process of the image buffer management memory 45, the image buffer management unit 44 first reads an offset value from the offset data 62 having an index number equal to the value of the control pointer variable held at that time (step ST11). The image buffer management unit 44 compares the read offset value with the offset value of the head data of the image data included in the request of the image processing unit 40, and the image buffer having the same index number as the offset data 62 from which the offset value has been read. It is determined whether the image data requested by the image processing unit 40 is stored in 61 (step ST12).

  For example, the offset value read from the offset data 62 is “0”, the storage capacity of one image buffer 61 is 3 kilobytes, and the image processing unit 40 has offsets from the first kilobyte to the second kilobyte. When image data is requested, the image buffer management unit 44 determines that the requested image data is stored in the image buffer 61. Under the same situation, when the image processing unit 40 requests image data having an offset from the 4th kilobyte to the 5th kilobyte, the image buffer management unit 44 stores the requested image data in the image buffer 61. Judge that it is not.

  When the image data requested by the image processing unit 40 is not stored in the image buffer 61 having the index number equal to the value of the control pointer variable, the image buffer management unit 44 stores the value of the control pointer variable and the image data. The next index number in the image buffer 61 to be updated is updated (step ST13).

  When there are n image buffers 61 as shown in FIG. 4, when the value of the control pointer variable is “n−1” (the last index number), the image buffer management unit 44 sets the value of the control pointer variable. Is updated to “0” (first index number). When the value of the control pointer variable is a value other than “n−1”, the image buffer management unit 44 increases the value of the control pointer variable by “1”.

  After updating the value of the control pointer variable, the image buffer management unit 44 reads the offset data 62 with the index number equal to the updated value of the control pointer variable (step ST11) and an image using the read offset value. Processing for determining the presence / absence of data (step ST12) is executed.

  By repeating the search processing from step ST11 to step ST13, the image buffer management unit 44 determines whether the image data requested by the image processing unit 40 is stored in the plurality of image buffers 61 for each image buffer 61. Judge one by one in turn.

  This search processing by the image buffer management unit 44 is repeated until an image buffer 61 that stores the image data related to the request is found. Since it is determined in advance that the image data related to the request is stored in any of the plurality of image buffers 61 based on the bitmap data 64, all the image buffers 61 are requested to be requested. It is not determined that such image data is not stored.

  When the image buffer management unit 44 determines that the requested image data is stored in the image buffer 61 in the value of a certain control pointer variable by the comparison process using the offset data 62, the specified image buffer Image data is read from 61 (step ST14). Further, the image buffer management unit 44 holds the value of the control pointer variable when it is determined that the image data is stored (step ST15).

  Thereafter, the image buffer management unit 44 extracts image data in the range requested by the image processing unit 40 from the image data read from the image buffer 61, and supplies the image data to the image processing unit 40 (step ST10). Thereafter, the image buffer management unit 44 returns to a state waiting for a request for image data (step ST3).

  When image data is required for the image buffer management unit 44 that operates as described above, the image processing unit 40 requests the necessary image data, and the image data acquired from the image buffer management unit 44 accordingly. Is used to execute print control data generation processing.

  Specifically, when the image is rotated 90 degrees and printed on the medium 30 (for example, when printing on the medium 30 sequentially from the leftmost column of the image in FIG. 3A), the image processing unit 40 prints Before generating the image, the image data of the file name designated for printing is sequentially acquired by a predetermined amount of data from the head image data of the file, and the head data of each line in the image file (in FIG. 3A) The offset value of the first data of the leftmost block of the image is specified. The image processing unit 40 causes the image processing memory 41 to store the offset value of the head data of each identified row.

  In particular, when the image data to be printed is JPEG image data, the data amount of each block in the image data is not constant. Before generating the print image, the image processing unit 40 sequentially acquires the image data of the file name designated for printing from the head image data of the file by a predetermined amount of data, and the head data of each line in the image file. Specify the offset value. The image processing unit 40 causes the image processing memory 41 to store the offset value of the head data of each identified row.

  In addition, when image processing such as APF processing is designated by an internal instruction of the print instruction interpretation unit 39, the image processing unit 40 has an image with a file name designated for printing before performing the processing on the image. Data is acquired sequentially from the first image data of the file by a predetermined amount of data, and parameters used for the image processing are generated. The image processing unit 40 stores the calculated parameters in the image processing memory 41.

  Further, the image processing unit 40 acquires image data of a file name designated for printing by a predetermined amount of data in the order of printing on the medium 30 by scanning the carriage 33, for example, in order to generate a print image. Is generated. When calculating parameters for image processing such as APF processing, the image processing unit 40 performs image correction processing using the parameters for the acquired image data, and uses the corrected image data To generate a print image. The image processing unit 40 stores the generated print image in the image processing memory 41.

  As described above, the image processing unit 40 uses the image data to be printed many times over the number of times according to the internal instruction for printing. At that time, the image processing unit 40 requests the image data in the order in which the image data is stored in the image file or requests the image data in an order different from the storage order in accordance with each process. The image processing unit 40 requests image data to be printed in an arbitrary order from the whole, and requests it microscopically in a continuous order.

  When the print image is generated, the image processing unit 40 performs color conversion processing for converting the color component of the generated print image into the ink color component of the printer 1 and printing presence / absence data for each ink color in dot units for printing. A halftone process for converting to a halftone process and an interlace process such as rearranging printing presence / absence data in dot units in the order of ink ejection from the carriage 33 are executed to generate print control data. The image processing unit 40 supplies the generated print control data to the control unit 42.

  When the print control data is supplied, the control unit 42 starts printing based on the print control data. First, the control unit 42 drives the feed motor 32 based on the supplied print control data, and supplies the medium 30 set in the printer 1 to a position facing the carriage 33 from a predetermined direction. The controller 42 applies a voltage to the plurality of piezoelectric elements of the carriage 33 based on the print control data while driving the carriage motor 34. As a result, a part of the image is printed on the part scanned by the carriage 33 of the medium 30. In addition, the control unit 42 repeatedly executes a control for driving the feed motor 32 to feed the medium 30 by a predetermined amount and a control for printing an image on a portion scanned by the carriage 33 of the medium 30 according to the print control data. As a result, the image designated in DSC 2 is printed on the medium 30 under the printing conditions designated in DSC 2.

  FIG. 7 is a list showing partial image data that the image buffer management unit 44 obtains in order from the DSC 2. The image buffer management unit 44 first acquires partial image data from 0 kilobytes to 2 kilobytes of image data to be printed, and then partial images from 15 kilobytes to 17 kilobytes of image data to be printed. Get the data. Similarly, partial image data is acquired in the order shown in FIG.

  FIG. 8 is a diagram showing the storage state of the image buffer memory 43 and the storage state of the image buffer management memory 45 when the eighth partial image data in FIG. 7 are acquired. The image buffer memory 43 has eight image buffers 61. The storage capacity of each image buffer 61 is 3 kilobytes.

  At this timing, the partial image data of 3 kilobytes with the offset value “0 to 2” is stored in the image buffer 61 with the index number “0”, and the offset value “0” is stored in the offset data 62 with the index number “0”. Is memorized. The image buffer 61 with the index number “1” stores the partial image data of 3 kilobytes with the offset value “15 to 17”, and the offset value “15” is stored in the offset data 62 with the index number “1”. . For the image buffer 61 and the offset data 62 from the index numbers “2” to “7”, as shown in FIG. In the bitmap data 64, the bit values from the first bit to the eighth bit corresponding to the partial image data are “present (1)”. The value of the same number of bits as the number of image buffers 61 is “present (1)”.

  FIG. 9 is a diagram showing the storage state of the image buffer memory 43 and the storage state of the image buffer management memory 45 when the ninth partial image data in FIG. 7 are acquired. At this timing, the partial image data of 3 kilobytes with the offset value “30 to 32” is stored in the image buffer 61 with the index number “0” having the oldest stored time data value in FIG. The offset value “30” is stored in the offset data 62. The other image buffer 61 and offset data 62 are the same as those in FIG. In the bitmap data 64, the bits from the second bit to the eighth bit from the head and the eleventh bit from the head are “present (1)”.

  As described above, in this embodiment, when image data is requested from the image processing unit 40, the image buffer management unit 44 first refers to the bitmap data 64 stored in the image buffer management memory 45. Thus, it is determined whether the image data relating to the request is stored in the plurality of image buffers 61. Then, when the image data related to the request is not stored in the plurality of image buffers 61, the image buffer management unit 44 acquires the image data from the DSC 2.

  Therefore, when the image data related to the request is not stored in the plurality of image buffers 61, the image buffer management unit 44 stores the image data related to the request in order for all of the plurality of image buffers 61. It is possible to determine that the image data relating to the request is not stored in the plurality of image buffers 61 and to quickly obtain the image data relating to the request without searching for whether or not the image data is being used. The image buffer management unit 44 can quickly acquire partial image data that is not stored in the plurality of image buffers 61 without executing a wasteful determination for the plurality of image buffers 61.

  In this embodiment, the bitmap data 64 is a bit array having a larger number of bits than the number of image buffers 61. Each bit of this bit arrangement is associated with each partial image data in the same order as the order of the partial image data in the image data to be printed. Therefore, even when the amount of image data to be printed is larger than the storage capacity of the plurality of image buffers 61, the image buffer management unit 44 grasps the acquisition status of the partial image data based on the bitmap data 64, and the necessary part. Image data can be acquired and provided. In addition, the requested image data can be provided by using a plurality of image buffers 61 having a total storage capacity smaller than the image data to be printed.

  In this embodiment, as in step ST9 of FIG. 5, the value of the control pointer variable is updated to the index number of the image buffer 61 that stores the partial image data. Therefore, after obtaining new partial image data from the DSC 2, the image buffer management unit 44 stores the partial image data obtained from the DSC 2 in step ST11 when requesting the next image data. The offset data 62 corresponding to 61 is read in order. Further, the image buffer management unit 44 acquires partial image data having a data amount larger than the requested image data. On the other hand, as described above, the image processing unit 40 requests image data in an arbitrary order from the whole, and microscopically requests it in a continuous order.

  Therefore, the image buffer management unit 44 has obtained a request for the next image data after acquiring new partial image data from the DSC 2, and when the image data relating to the request is stored in the image buffer 61. In many cases, it is determined that the image data requested by the image processing unit 40 is stored in the image buffer 61 only by searching for one offset data 62.

  In this embodiment, in step ST15 of FIG. 5, the value of the control pointer variable is held in the index number of the image buffer 61 from which the partial image data is read. Therefore, if the requested image data is stored in the image buffer memory 43, the image buffer management unit 44 stores the previous image data when the next image data is requested. The image buffer 61 is searched in order. The image buffer management unit 44 acquires partial image data having a larger data amount than the requested image data.

  Therefore, when the next image data is requested after the image data is read from the image buffer 61 and supplied to the request source, and the image data relating to the request is stored in the image buffer 61, the image buffer In many cases, the management unit 44 determines that the image data requested by the image processing unit 40 is stored in the image buffer 61 only by searching for one offset data 62.

  The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications and changes can be made without departing from the scope of the invention. It is.

  For example, in the above embodiment, the total image buffer management memory 45 and the image buffer memory 43 are provided separately. In addition to this, for example, a plurality of offset data 62 and the like may be provided in the image buffer memory 43, and these may be used as one memory.

  In the above embodiment, the print instruction unit 17 of the DSC 2 transmits a print instruction specifying the file name of the EXIF image file 21 having the image data of the image to be printed to the print instruction interpretation unit 39 of the printer 1. In addition to this, for example, the print instruction unit 17 issues a print instruction specifying a file ID used in PictBridge, etc., which is issued in a one-to-one correspondence with the file name, to the print instruction of the printer 1. You may make it transmit to the interpretation part 39. FIG. Note that PictBridge uses PTP (Picture Transfer Protocol) to transmit image data from the DSC 2 to the printer 1.

  In the above embodiment, the image buffer management unit 44 is provided in the printer 1 connected to the DSC 2 and reads the data of the EXIF image file 21 stored in the semiconductor memory 13 of the DSC 2. In addition, for example, the image buffer management unit 44 is provided in the printer 1 connected to a digital movie camera, a card reader, a semiconductor memory, a portable terminal, a computer, etc., and reads image data stored in these. May be.

  The present invention can be used in, for example, a printer that is connected to a digital camera and prints an image based on an image file stored in the digital camera.

It is a figure which shows the printer and DSC which concern on embodiment of this invention. It is a block diagram which shows a structure in case DSC is operate | moving in imaging mode. It is explanatory drawing of the production | generation process of EXIF image data by an image data production | generation part. It is explanatory drawing of an image buffer memory and an offset data memory. It is a flowchart which shows operation | movement of an image buffer management part. It is explanatory drawing of the data acquisition of an image process part and an image buffer management part. It is an example of the transmission request list | wrist of an image buffer management part. It is a figure which shows the memory | storage state when the 8th request | requirement of FIG. 7 is made. It is a figure which shows the memory | storage state when the 9th request | requirement of FIG. 7 is made.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Printer (printing apparatus), 40 Image processing part (image processing means), 42 Control part (printing means), 43 Image buffer memory, 44 Image buffer management part (judgment means, acquisition means, supply means), 45 Image buffer management Memory (presence / absence information storage means), 61 image buffer, 64 bitmap data (presence / absence information)

Claims (8)

A plurality of image buffers each storing one of a plurality of partial image data obtained by dividing image data to be printed by a predetermined size unit;
For each partial image data, presence / absence information storage means for storing presence / absence information indicating whether or not the partial image data is stored in any of the image buffers;
When there is a request for any image data in the image data to be printed, the partial image including the image data related to the request is referred to by referring to the presence / absence information corresponding to the partial image data including the image data related to the request Determining means for determining whether data is stored in the image buffer;
When the determination means determines that the partial image data including the image data relating to the request is not stored in any of the image buffers, the partial image data including the image data relating to the request is obtained from a predetermined acquisition source. Acquisition means for acquiring and storing in the image buffer and updating the presence / absence information corresponding to the partial image data;
An image data cache device comprising:   The presence / absence information storage means stores, as the presence / absence information, a bit array having 1-bit data equal to the number of the partial image data and in which each partial image data is associated with each 1-bit data. The image data cache device according to claim 1.   The bit arrangement includes 1-bit data as the presence / absence information associated with each partial image data in the same order as the order of the partial image data in the image data to be printed. The image data cache device described.   When the acquisition unit acquires the partial image data including the requested image data from a predetermined acquisition destination and overwrites and stores the partial image data in the image buffer, the partial image erased by overwriting the image buffer 2. The image data cache device according to claim 1, wherein the presence / absence information corresponding to data is updated.   Only when it is determined by the determination means that partial image data including image data related to the request is stored in the image buffer, the image data related to the request is searched in the image buffer, and the image data related to the request is 2. The image data cache apparatus according to claim 1, further comprising supply means for reading from the image buffer and supplying the read data to the request source.   2. The image data cache apparatus according to claim 1, wherein the acquisition unit acquires the partial image data including image data relating to the request from a digital camera, a card reader, a semiconductor memory, a portable terminal, or a computer. The image data cache device according to any one of claims 1 to 6, wherein image data relating to a request is supplied to the request source;
Image processing means for requesting image data in an image to be printed to the image data cache and generating print control data using the image data supplied accordingly;
Printing means for executing printing based on the print control data;
A printing apparatus comprising: When there is a request for any image data in the image data to be printed, the presence / absence information indicating whether or not the partial image data is stored in any of the image buffers is stored for each partial image data. Reading the presence / absence information corresponding to the partial image data including the image data related to the request from predetermined presence / absence information storage means;
Determining whether or not the partial image data including the requested image data is stored in the image buffer based on the read presence / absence information;
When the determination means determines that the partial image data including the image data relating to the request is not stored in any of the image buffers, the partial image data including the image data relating to the request is obtained from a predetermined acquisition source. Obtaining and storing in the image buffer and updating the presence / absence information corresponding to the partial image data;
An image data cache method comprising:

Images