JPH05162305A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To prevent the life of an ink jet head from being shortened even when a drawing containing a contour line specifying a drawing region is drawn. CONSTITUTION:CAD data (plotter command) containing a contour and a drawing is stored in an input buffer 1 and the internal (intermediate) data obtained in an analyzing part 2 is shifted in the line direction of an ink jet head on the basis of the reference point P from a reference point altering part 12 in a contour figure data shift part 3. The drawing data developed to the bit map data in a bit map data developing processing part 4 is stored in a frame buffer 5. The drawing data is successively read by a controller 6 to be successively supplied to a shift register 8. A roll paper replacement detection part 11 detects the replacement of roll paper and the reference point altering part 12 alters the reference point P stored in a memory part 10 when the replacement of the roll paper is detected to shift contour figure data in the line direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus such as an ink jet plotter using an ink jet head having a large number of nozzles arranged in a line.

[0002]

2. Description of the Related Art Conventionally, in the field of automatic drafting machines and the like, an ink jet recording apparatus using an ink jet head has been used along with a pen plotter in terms of high speed of drawing, low noise and easy maintenance. As is well known, the inkjet head is a multi-nozzle head in which a large number of nozzles are arranged in an array, or a slit-type inkjet head that ejects liquid ink by a selective applied voltage from a slit-shaped ink outlet to an internal electrode array. However, here, the ink jetting location including the latter head is referred to as a "nozzle".

By the way, generally, in order to specify the drawing area in the drawing, a contour line is drawn on the peripheral portion by a thick solid line (0.5 mm or more). A title block is provided at the lower right of this outline. The contour line may be transmitted from the CAD system to the inkjet recording apparatus together with the graphic data, or may be set inside the inkjet recording apparatus according to the size of the recording paper.

[0004]

The contour line is the longest straight line in the drawing. In an inkjet recording device, when drawing such a long straight line in the paper transport direction,
It is necessary to continuously eject ink from a specific nozzle of the inkjet head. In particular, the recording position of such an outline is uniquely determined according to the paper size. Therefore, the nozzle that draws the contour line has a higher frequency of ejecting ink than the other nozzles, and thus is subject to more severe use conditions such as being subjected to more viscous friction than other nozzles. Therefore, the life of the entire head is determined by the life of the nozzle that draws the contour line.

As described above, in the ink jet recording apparatus for outputting the drawing data, there is a peculiar circumstance in which a specific nozzle is overused to draw a contour line. For this reason, when the ink jet head as a whole is seen, the number of printed sheets is small. However, there is a problem that the life of the entire inkjet head is shortened due to the deterioration of some specific nozzles.

The present invention has been made in view of the above problems, and an ink jet recording apparatus capable of effectively preventing the life of an ink jet head from being extremely shortened even when a drawing including a contour line is drawn. The purpose is to provide.

[0007]

An ink jet recording apparatus according to the present invention analyzes a drawing data including a contour line that specifies a drawing area of a drawing and a graphic drawn in the contour line, and develops a bitmap. Image processing means, frame storage means for storing the drawing data expanded into bitmap data by the image processing means, control means for sequentially reading out the drawing data stored in the frame storage means and controlling each part A sheet conveying means for conveying the recording sheet under the control of the control means, and an ink jet head for outputting the contour line and the figure on the recording sheet on the basis of the drawing data sequentially read from the frame storing means. In the ink jet recording apparatus provided, a paper exchange detecting means for detecting that the recording paper has been exchanged, and Replacement of the recording paper in the paper replacement detecting means is characterized in that a contour-shape shifting means for shifting the position of the drawing data in the nozzle array direction of the ink-jet head each time it is detected.

The contour line in the drawing data may be supplied from an external CAD system or the like together with the figure,
It may be set according to the paper size inside the inkjet recording apparatus. Further, the contour / figure shift means may shift the storage position of the screen data in the frame storage means at the time of, for example, bit map expansion, or at the time of transfer from the frame storage means to the inkjet head. It may be one that controls the shift amount of the graphic data.

[0009]

[Function] According to JIS (machine drawing), the left and right margins of the outline of the drawing are 20 mm or more in the large drawing (A0, A1),
In the small and medium-sized drawings (A2 to A3), the width is specified to be 10 mm or more, and 25 mm or more when the left side is used as the binding margin, but in practice, a width of about ± 2 mm is allowed. According to the present invention, the position of the drawing data in the nozzle arrangement direction of the inkjet head is shifted within this width range each time the recording paper exchange is detected. For this reason,
Each time the recording paper is replaced, the position of the contour line shifts, which also shifts the nozzle position of the inkjet head that draws the contour line.

As described above, according to the present invention, it is possible to change the nozzle that draws the contour line in the sheet conveying direction every time the recording paper is replaced, so that the contour line is drawn only by a specific nozzle as in the conventional case. Compared with the case, the usage time of the nozzle can be shortened to several tenths to several tenths. Therefore, the life of the inkjet head can be significantly extended as compared with the conventional case.

Further, according to the present invention, the timing for shifting the drawing data is when the recording paper is replaced. Usually, when the recording paper is replaced, its set position often deviates slightly from the previous set position. For this reason, even if the contour line is shifted for each recording sheet, it will not be noticeable unless the shift amount is extremely large. Moreover, in the present invention, the position of the contour line does not change unless the recording paper is replaced, so that there is no problem due to the shift of the contour line in the drawings of the same lot.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a functional block diagram showing the configuration of an inkjet plotter according to the first embodiment of the present invention. Drawing data including contour lines and figures is, for example, A
It is transmitted from a CAD system (not shown) in the form of CAD data (plotter command) composed of an SCII coat. This CAD data (plotter command) is stored in the input buffer 1. CA stored in input buffer 1
The D data (plotter command) is analyzed by the analysis unit 2 and converted into internal (intermediate) data composed of vector data. The internal (intermediate) data obtained by the analysis unit 2 has its arrangement position determined by the contour / graphic data shift unit 3, and the bitmap expansion processing unit 4 determines the DDA (Digital differential a).
nalyzer) processed and expanded into bitmap data. The obtained bitmap data is stored in the frame buffer 5.

The bitmap data stored in the frame buffer 5 is sequentially read by the controller 6. The controller 6 uses the paper transport unit 7
Is controlled to control the conveyance of the recording paper, and the drawing data read from the frame buffer 5 is sequentially supplied to the shift register 8. The shift register 8 sends the supplied drawing data to the inkjet head 9. The inkjet head 9 performs necessary recording on a recording sheet (not shown) according to the drawing data.

On the other hand, in this ink jet plotter,
The storage unit 10 that stores the layout reference points of the drawing data, the roll paper exchange detection unit 11 that detects that the roll paper that is the recording paper has been exchanged, and the roll paper exchange detection unit 11 that detects the roll paper exchange A reference point changing unit 12 is provided that changes the reference point stored in the storage unit 10 each time. For the storage unit 10, a non-volatile memory such as an EEPROM is used. The reference point changed by the reference point changing unit 12 is supplied to the contour / graphic data shift unit 3 as data for specifying the reference point when the bitmap is developed.

Next, the operation of the ink jet plotter according to this embodiment having the above structure will be described. FIG. 2 is a flowchart showing the operation of the plotter.
When CAD data (plotter command) is stored in the input buffer 1 and is analyzed by the analysis unit 3 and converted into internal (intermediate) data, the flow of FIG. 2 is activated. First, the reference point changing unit 12 reads the reference point P from the storage unit 10 (S1), and checks whether or not the roll paper exchange detection unit 11 detects the exchange of roll paper (S2). If the roll paper exchange is not detected, the printing process for one sheet is executed as it is (S8), and if it is detected, the reference point P is counted up (S3). In this case, if the reference point P exceeds the maximum shift amount PL, P is reset to 0 (S4, S5). The maximum shift amount PL is determined by the permissible width (± 2 mm) of the deviation of the contour line, the arrangement pitch of the nozzles of the inkjet head 9 and the one shift pitch. The updated reference point P is stored in the storage unit 10 (S6). Then, the contour / graphic data shift unit 3 determines the position where the drawing data should be arranged with reference to the reference point P. That is, the reference point P is added to the X (line direction) coordinate of each vector forming the drawing data (S7). Next, the print processing for one sheet (S8) is executed. The above processing is continued until printing is completed (S
9). Even if the recording paper is replaced before the required number of prints is completed, the reference point P is updated.

FIG. 3 is a diagram for explaining the operation of the present inkjet plotter. In the drawing before the roll paper is replaced, as shown in FIG.
The nozzles P1 and P2 of No. 1 were continuously used to draw the vertical line of the contour line 21. However, in the drawing after the roll paper replacement, as shown in FIG. 22
Since both of them are shifted to the left by one pitch of the nozzles, the nozzles of the inkjet head 9 that draw the vertical line of the contour line 21 are changed to P3 and P4, and P1 and P1, respectively.
Continuous use of P2 will be prevented.

When the nozzles are arranged at a pitch of 16 dots / mm and the contour line is 0.5 mm, the contour line is drawn by nozzles for 8 dots. If the shift operation is carried out dot by dot, and if the allowable width is set to 2 mm, the process goes round once for 32 shift operations. in this case,
Even the resistor that generates heat for the longest time can be shortened to 1/4 the energization time of the conventional one.

FIG. 4 is a functional block diagram showing the structure of an ink jet plotter according to the second embodiment of the present invention.
In FIG. 4, the same parts as those in FIG. 1 are designated by the same reference numerals, and the description of the overlapping parts will be omitted. In the first embodiment, the shift processing is performed on the internal (intermediate) data immediately before the bitmap expansion, but in the second embodiment, the data shift processing is performed after the bitmap expansion. ..

That is, in general, in this type of inkjet plotter, the entire printable range of the inkjet head is not used, but the inkjet head is provided with a margin of several dots at both ends. Therefore, in this embodiment, the reference point P supplied from the reference point changing unit 12 to the controller 31 is changed every time the roll paper is replaced. The controller 31 changes the feed amount of the drawing data to the shift register 8 according to the reference point P. As a result, the position of the drawing data with respect to the inkjet head 9 can be changed every time the roll paper is replaced, and the same effect as that of the above embodiment can be obtained.

According to this embodiment, since it is not necessary to change the coordinate of each vector data, the processing time required for the coordinate conversion can be shortened and the processing up to the bit map expansion can be made common. There are advantages.

FIG. 5 is a functional block diagram showing the structure of an ink jet plotter according to the third embodiment of the present invention.
In FIG. 5, the same parts as those in FIG. 1 are designated by the same reference numerals, and the description of the overlapping parts will be omitted. In this example, C
The present invention is applied to a case where contour data is not transferred as CAD data (plotter command) from the AD system.

That is, the ink jet plotter is provided with a paper size input device 41, a contour line is generated by the contour data setting section 42 according to the input condition of the paper size input device 31, and this contour line is contoured. It is supplied to the graphic data shift unit 3. The processing after the shift of the contour / graphic data supplied to the contour / graphic data shift unit 3 is the same as in the first embodiment.

In the above embodiments, the ink jet plotter is taken as an example, but it goes without saying that the present invention can be applied to other ink jet recording apparatuses.

The ink jet head is not limited to the fixed type. For example, even in an ink jet recording apparatus of a type in which the width of the ink jet head in the line direction is narrower than the paper width and one line of recording is performed by moving the head in the line direction, there is a problem that a specific nozzle is overused. Occur. Even in this case, the effects described above can be obtained by performing the nozzle shift operation as in the present invention.

[0025]

As described above, according to the present invention, since the nozzle position of the ink jet head for drawing the contour line is changed every time the recording paper is replaced, the nozzle for drawing the contour line is used. The time can be shortened to several tenths to several tenths of the conventional case. As a result, it is possible to prevent only specific nozzles of the inkjet head from being overused, and it is possible to significantly improve the life of the entire inkjet head.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a configuration of an inkjet plotter according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of the plotter.

FIG. 3 is a diagram for explaining a drawing form by the plotter.

FIG. 4 is a functional block diagram showing a configuration of an inkjet plotter according to a second embodiment of the present invention.

FIG. 5 is a functional block diagram showing a configuration of an inkjet plotter according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Input buffer, 2 ... Analysis part, 3 ... Outline / graphic data shift part, 4 ... Bitmap expansion processing part, 5 ... Frame buffer, 6,31 ... Controller, 7 ... Paper conveyance part,
8 ... Shift register, 9 ... Inkjet head, 10
... storage section, 11 ... roll paper exchange detection section, 12 ... reference point changing section, 41 ... counter, 21 ... contour line, 22 ... figure,
41 ... Paper size input device, 42 ... Contour data setting section.

Claims (5)

[Claims] 1. An image processing unit for analyzing a drawing data including a contour line for specifying a drawing area of a drawing and a figure drawn in the contour line and developing a bitmap, and bitmap data by the image processing unit. A frame storage means for storing the drawing data developed in the above, a control means for sequentially reading out the drawing data stored in the frame storage means and controlling each part, and a recording sheet conveyed under the control of the control means. In an inkjet recording apparatus including a sheet conveying unit and an inkjet head that outputs the contour line and the graphic to the recording sheet based on the drawing data sequentially read from the frame storage unit, the recording sheet is replaced. The paper exchange detection means for detecting that the exchange of the recording paper is detected by the paper exchange detection means. An ink jet recording apparatus characterized by comprising a contour-shape shifting means for shifting the position of the drawing data in the nozzle array direction of the inkjet head. 2. The ink jet recording apparatus according to claim 1, wherein the contour line in the drawing data is supplied from the outside together with the figure. 3. A paper size input means for inputting the size of the recording paper, and a contour setting means for setting a contour line in the drawing data based on the size of the recording paper input by the paper size input means. The inkjet recording apparatus according to claim 1, further comprising: 4. The ink jet recording apparatus according to claim 1, wherein the contour / graphic shift means shifts a storage position of the drawing data in the frame storage means. .. 5. The contour / graphic shift means is provided inside the control means, and controls the shift amount of the drawing data transferred from the frame storage means to the inkjet head. The inkjet recording apparatus according to claim 1.