JP2007038577A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for controlling an inkjet recorder which makes high speed or high image quality recording. <P>SOLUTION: The image forming device scans a carriage loading a recording head at a predetermined speed, based on image data received from a host device in a data frame unit obtained by splitting with an arbitrary split number the image data necessary for recording single scanning image with the quantity of recording element width. The device comprises; a storing means for storing data frame which is divided into a plurality of predetermined regions; an image recording control means for controlling the device to start recording of an image using the data frame having storage completed upon detecting the data frame being stored in one or more predetermined regions; a setting means for setting at least two recording modes; and a controlling means for interrupting the recording of an image when the storage of the data frame to be recorded next is not completed after starting image recording and controlling the amount of return for returning the carriage in the direction of the recording start position from the interruption position corresponding to the recording mode by the setting means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image recording apparatus, and more particularly to a technique for realizing an inexpensive, high-speed and high-quality image recording apparatus.

  Conventionally, a carriage equipped with a recording head is scanned in a main scanning direction to record on a recording medium, and a sufficient amount of memory is not secured to store all data to be printed in one main scanning. When a part of the recording data to be recorded is stored in the memory, the main scanning of the recording head is started, and the memory of the part where the sequential printing is completed is used as a memory for storing the next recording data. In an inkjet recording apparatus that uses rectangular blocks in the main scanning direction and the sub-scanning direction, printing is stopped when the number of received blocks is less than a predetermined number, and then printing is performed when additional data can be stored for a predetermined number of blocks. It was resuming. At this time, if printing is stopped and printing is resumed within the same scan, there is a problem that the image quality of the image connection portion where the restart is resumed is deteriorated. One cause is carriage overshoot.

  Here, the overshoot means that a speed fluctuation occurs due to a natural frequency of the carriage for a predetermined period immediately after the carriage shifts from acceleration to constant speed driving. To resume printing, the carriage with the recording head must be returned at least by the acceleration distance. If the return distance is too short, ink will be ejected during overshoot when the carriage moves from acceleration to constant speed. Which leads to degradation of image quality. Therefore, it is conceivable to drive so that printing is started when sufficient acceleration area of the carriage is taken and the overshoot is eliminated after entering the constant speed area. However, if the carriage is uniformly returned to the recording start position in all scenes at the start of recording after interruption, the printing speed cannot be increased.

Moreover, as a prior art example, patent document 1 and patent document 2 can be mention | raise | lifted, for example.
Japanese Unexamined Patent Publication No. 7-323637 JP 2003-320655 A

  As described above, the carriage mounted with the recording head is scanned in the main scanning direction to record on the recording medium, and a sufficient amount of memory is not secured to store all the data to be printed in one main scanning. The configuration is such that the main scanning of the recording head is started when a part of the recording data to be recorded in the main scanning is stored in the memory, and the memory of the portion where the sequential printing is completed is used as a memory for storing the next recording data. In the recording apparatus, if the carriage main scan restart position is set to a fixed position during the print restart process when the additional data cannot be stored in the memory, high-precision printing cannot be performed in the image quality priority mode. There is a fear. In the speed priority mode, the printing speed may be slow.

  It is an object of the present invention to store additional data to be recorded in a memory in time in an inexpensive recording apparatus that does not secure a sufficient amount of memory for determining all data to be printed in one main scanning. An object of the present invention is to provide a method of controlling an ink jet recording apparatus that realizes high speed or high image quality by making the carriage main scan resuming position variable when resuming printing when there is no ink.

The image recording apparatus according to the present invention provides image data received from a host apparatus in units of data frames obtained by dividing image data necessary to record an image for one scan by the number of recording elements of a recording head by an arbitrary number of divisions. An image recording apparatus for recording an image while scanning a carriage mounted with the recording head on a recording medium at a predetermined speed,
Storage means for storing the data frame divided into a plurality of predetermined areas;
An image recording control means for controlling to start image recording using the data frame for which the storage has been completed when it is detected that the storage of the data frame in one or more of the predetermined areas is completed;
Setting means for setting at least two recording modes;
If the storage of the next data frame to be recorded is not completed after the start of the image recording, the image recording is interrupted, and a return amount for returning the carriage from the interruption position to the recording start position is set by the setting means. It is characterized by comprising a control means for controlling according to the recording mode. Further, when the recording mode is set to the speed priority mode, the return amount of the carriage toward the recording start position is set to a shorter distance than when the image quality priority mode is set. is there.

  As described above, according to the present invention, in an inexpensive recording apparatus that does not secure a sufficient amount of memory for determining all data to be printed in one main scan, transfer of additional data to a printing operation during printing is performed. By changing the carriage main scan resuming position when resuming printing when the time is not in time, a high-speed and high-quality recording apparatus can be provided without reducing the throughput.

  FIG. 1 is a perspective view schematically showing an ink jet recording apparatus to which the present invention can be applied. The recording medium 105 inserted into the paper feeding position of the recording apparatus 100 is fed in the direction of arrow P by the feed roller 106 and conveyed to the printable area of the recording head 104. A platen 107 is provided below the recording medium 105 in the printable area. The carriage 101 is movable in the direction along the axial direction by two guide shafts 102 and 103, and the scanning region including the printing region is the main scanning direction by driving a stepping motor (not shown). Reciprocal scanning is performed along the directions indicated by arrows Q1 and Q2. When one main scanning is completed, the recording medium is fed by a fixed amount in the sub-scanning direction, which is the direction of arrow P, to prepare for the next main scanning. These main scanning and sub-scanning are repeated to perform one page printing operation.

  In FIG. 1, a recording head 104 mounted on a carriage 101 includes a discharge port that can discharge ink and an ink tank that stores ink. The discharge port of the recording head applies ink to a recording medium located below. It is mounted on the carriage so as to discharge and print.

  Reference numeral 108 denotes a switch unit and a display unit, and the switch unit is used for switching on / off the power of the recording apparatus, setting various printing modes, and the like. Here, the print mode is set by the switch of the recording apparatus main body, but it may be set by an instruction from the host. The display unit is configured to be able to display the status of the recording apparatus.

  The configuration of the recording head is capable of printing four colors Y, M, C, and Bk, the number of Y, M, and C ejection openings is 128 each, and the number of Bk is 320, and the arrangement of ejection openings for each color The pitch is 1/600 dpi with respect to several sub-scanning directions, and is about 42 microns. The drive frequency of the recording head is 15 kHz, and a printing operation is possible at a density of 600 dpi in the main scanning direction. Therefore, the main scanning speed of the carriage during the printing operation is 25 inches / second.

  FIG. 2 is a block diagram showing the main part of an ink jet recording apparatus to which the present invention is applicable. Character or image data to be printed is transmitted from the host apparatus 500 to the recording apparatus 100 and stored in the reception buffer 401. Further, data for confirming whether the data is correctly transferred and data for informing the operation state of the recording apparatus 100 are transmitted from the recording apparatus 100 to the host apparatus 500.

  The data stored in the reception buffer 401 is processed into data for printing when the recording head performs main scanning under the control of the CPU 402, and is stored in the print buffer unit in the random access memory unit 403. The data of the print buffer unit is transferred to the recording head 104 by the recording head control unit 410, and the recording head is controlled to print character and image data. Further, the recording head control unit 410 detects temperature information indicating the state of the recording head 104 and sends it to the CPU 402, transmits the information to the recording head control unit 410, and controls the recording head.

  A machine control unit 404 drives and controls a machine unit 405 such as a carriage motor or a line feed motor in response to a command from the CPU 402.

  The sensor / SW control unit 406 sends a signal from the sensor / SW unit 407 including various sensors and SW (switch) to the CPU 402.

  The display element control unit 408 is configured to control the display unit 409 composed of LEDs, liquid crystal display elements, and the like of the display panel group according to a command from the CPU 402.

  In the present invention, the capacity of the print buffer is a memory configuration having a capacity smaller than a memory amount sufficient to determine all data to be printed in one main scan.

  The following embodiment shows an example in which color printing is performed, and one-pass printing is performed using 128 Y, M, C, and Bk discharge ports of the recording head.

  The configuration of the print buffer is to print a full print width of 8 inches at a density of 600 dpi, and the maximum possible print buffer width is less than that of 4800 dots corresponding to the full width, and a width greater than 1/2. 2560 dots. As a result, it is necessary to secure 4800 dots of memory, which is about 1/2.

For details on the print buffer configuration, see
In this embodiment, B, which is distinguished for each color of A, Y, M, C, Bk, is ensured by a rectangular block of print pixel units in the vertical (sub-scanning) direction and the horizontal (main scanning) direction. In this embodiment, the block size is set to a constant value within one main scan, and the vertical size (height) of the block can be set.
In this embodiment, n1 times 8 (n1 is an integer of 1 or more)
In this embodiment, n1 = 16 is set to 128, and the horizontal size (width) of the block is settable.
In this embodiment, 2 to the power of n2 (n2 is an integer of 0 or more).
In this example, n2 = 8 and 256. Therefore, for the print width,
In the horizontal direction, a maximum of 2560/256 = 10 blocks can be applied.
E. In the main scan to print, blocks without data for each color do not secure a memory area,
By using a zero flag as a substitute and handling it as null data when printing, the memory can be saved. In this way, the rectangular block configuration makes memory management easier. In addition, the block size has a variable structure, and it is possible to flexibly respond to the effective use of the memory according to the printing conditions.

  In this embodiment, the block management is made a multiple of 16 to facilitate memory management. In addition, memory management is facilitated by setting the width of the block size to a power of 2.

  FIG. 3 shows an outline of block buffer processing of the present invention. As shown in FIG. 3-1, when printing 8 inch wide data on an A4 size recording medium in one scan (main scan), it is necessary if the resolution in the main scan direction is 600 dpi and the block width is 256 dots. The number of correct blocks is 19 blocks. The number of blocks that can actually be secured from the memory procedure installed in the recording apparatus is five blocks. Recording is performed by sequentially using the block buffers that can be secured in a ring shape. A white block indicates an empty block for which data has not been received, and a shaded block is a recording processing waiting block for which data has been received. In the state shown in FIG. 3B, all the block buffers are in an empty state in a recording data reception waiting state. When the recording data is received and more than a predetermined block (4 blocks in this example) is received, the recording head is driven in the main scanning direction to start recording (see FIG. 3-3). When the recording of one block buffer is completed, a block buffer recording completion interrupt is generated (see FIGS. 3-3 to 3-9). In the interrupt processing, it is checked whether there is a recording processing waiting block. If it is determined that there is no waiting block (the next block to be printed is empty), printing is interrupted and carriage stop processing is started (see FIG. (See 3-8).

  FIG. 4 shows an outline of carriage operation processing when printing is interrupted. A white rectangle represents a recording area on a recording medium printed by one main scan. Before the start of one main scan, the carriage is stopped at [1. Carriage main scan start position] (see FIG. 4A). In Fig. 4-2, the carriage starts the main scan, and since the additional data cannot be stored in the memory in time, the print is interrupted at [2. Print interrupt position], decelerated, and at [3. CR stop position]. Stop. In the speed priority mode, as shown in FIG. 4C, the carriage is returned by an acceleration distance from [2. Printing stop position], and when additional data is stored, it waits so that printing can be resumed immediately. In the image quality priority mode, the printer returns to [1. Carriage scan start position] and waits in order to prevent image quality degradation due to carriage overshoot when resuming printing. In either case, printing is resumed as soon as additional data for a predetermined block is accumulated (see FIG. 4-5).

FIG. 5 is a flowchart relating to a method for setting a carriage main scanning restart position when printing is interrupted. When printing is started, a block printing completion interrupt is generated every time one block ends (S501). In the block printing completion interrupt process, it is determined whether the printing is finished (S502) or the printing is interrupted (S504). If the printing is finished, the process proceeds to S503 and the printing process is finished. In the case of printing interruption, the printing interruption position is stored and the interruption process is exited (S505). After the printing is interrupted, the carriage is stopped (S506), and the printing mode is determined (S507). As a result, if it is the speed priority mode, the carriage is returned by the acceleration distance from the stored print interruption position (S508). If it is in the image quality priority mode, the carriage is returned to the position where the current main scan is started (S511). Thereafter, the process waits until print data is accumulated for a predetermined number of blocks (S509).
When the print data is accumulated, the main scanning of the carriage is started and the printing process is resumed (S510).

The perspective view which shows the outline of the inkjet recording device which can apply this invention Block diagram of inkjet recording device Block buffer processing explanatory diagram Explanatory diagram showing the printing mode and the main scanning restart position of the carriage when printing is interrupted A flowchart showing a method for setting a carriage main scan start position when printing is resumed

Explanation of symbols

100 Recording device 101 Carriage 102 Guide shaft a
103 Guide shaft b
DESCRIPTION OF SYMBOLS 104 Recording head 105 Recording medium 106 Feed roller 107 Platen 108 Switch part and display part 401 Reception buffer 402 CPU
403 Random access memory unit 404 Machine control unit 405 Machine unit 406 Sensor / SW control unit 407 Sensor / SW unit 408 Display element control unit 409 Display element unit 410 Recording head control unit 411 Read only memory 500 Host device

Claims (2)

Equipped with the recording head based on the image data received from the host device in units of data frames obtained by dividing the image data required to record an image for one scan with the number of recording elements of the recording head by an arbitrary number of divisions An image recording apparatus for recording an image while scanning the carriage at a predetermined speed on a recording medium,
Storage means for storing the data frame divided into a plurality of predetermined areas;
An image recording control means for controlling to start image recording using the data frame for which the storage has been completed when it is detected that the storage of the data frame in one or more of the predetermined areas is completed;
Setting means for setting at least two recording modes;
If the storage of the next data frame to be recorded is not completed after the start of the image recording, the image recording is interrupted, and a return amount for returning the carriage from the interruption position to the recording start position is set by the setting means. An image recording apparatus comprising control means for controlling in accordance with a recording mode according to.   2. The recording apparatus according to claim 1, wherein when the recording mode is set to a speed priority mode, the return amount of the carriage in the recording start position direction is set to a shorter distance than when the image quality priority mode is set. Image recording device.

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