JPH05162308A - 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 figure is stored in an input buffer 1 and the internal (intermediate) data obtained in an analyzing part 2 is inputted to a contour data extraction part 3 and only a contour line is extracted. The extracted contour line 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 13 in a contour data shift part 4. The drawing data developed to bit map data in a bit map developing processing part 5 is stored in a free buffer 6 and successively read by a controller 7 to be successively supplied to a shift register 9. The reference point altering part 13 alters the reference point P stored in a memory part 11 at each time when a power supply switch 12 is closed to shift contour 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 specifying a drawing area of a drawing and a figure 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, and 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 based on the drawing data sequentially read from the frame storing means. In the inkjet recording apparatus provided, the nozzle arrangement of the inkjet head is changed every time the power switch is turned on. Characterized by comprising a contour shift means for shifting only the position of the contour lines in the drawing data in a direction.

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. In the former case, it is necessary to further include contour data extraction means for extracting only the contour line from the drawing data. Further, the contour shift means may shift the storage position of the contour data in the frame storage means, for example, when the bitmap is developed.

[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, for example, within this width range, only the position of the contour line in the drawing data in the nozzle arrangement direction of the inkjet head is shifted each time the power switch is turned on. Therefore, the position of the contour line shifts each time the power is turned on, and the nozzle position of the inkjet head that draws the contour line shifts accordingly.

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 each time the power is turned on. Therefore, when the contour line is drawn only by a specific nozzle as in the conventional case. In comparison, 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, since only the contour line is shifted, the amount of data used for the shift processing is small, and the shift processing does not spend much time.

Further, according to the present invention, the timing for shifting the contour line is when the power is turned on. Usually, related drawings are often output collectively when the power is turned on once. Therefore, the contour shift occurs only between the drawings of different lots, and the drawings of the same lot have a problem due to the deviation of the contours. There is no such thing. Therefore, the deviation of the contour line is not noticeable.

[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. Of the internal (intermediate) data obtained by the analysis unit 2, only the contour line is extracted by the contour data extraction unit 3. The extracted contour line is subjected to shift processing by the contour data shift unit 4 to determine the arrangement position. The drawing data including the contour line whose position has been determined is DDA (Digi
tal differential analyzer) and processed into bitmap data. The obtained bitmap data is
It is stored in the frame buffer 6.

The bitmap data stored in the frame buffer 6 is sequentially read by the controller 7. The controller 7 includes a paper transport unit 8
Is controlled to control the conveyance of the recording paper, and the drawing data read from the frame buffer 6 is sequentially supplied to the shift register 9. The shift register 9 sends the supplied drawing data to the inkjet head 10. The inkjet head 10 performs necessary recording on a recording sheet (not shown) according to the drawing data.

On the other hand, in this ink jet plotter,
A storage unit 11 that stores the contour reference point, a power switch 12 for turning on the power of the plotter, and a reference that changes the reference point stored in the storage unit 11 each time the power switch 12 is turned on. A point changing unit 13 is provided. A non-volatile memory such as an EEPROM is used for the storage unit 11. The reference point changed by the reference point changing unit 13 is supplied to the contour data shift unit 4 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 the power switch 12 is turned on, the flow of FIG. 2 is activated. First, the reference point changing unit 13 reads the reference point P from the storage unit 11 (S1) and counts up the reference point P (S2). At this time, if the reference point P exceeds the maximum shift amount PL, P is reset to 0 (S3, S
4). The maximum shift amount PL is the permissible width of the deviation of the contour line (±
2 mm), the arrangement pitch of the nozzles of the inkjet head 9 and the shift pitch of once, and the like. The updated reference point P is stored in the storage unit 11 (S5).

Next, waiting for data input (S6), CAD data (plotter command) is stored in the input buffer 1, and when this is analyzed by the analysis unit 3 and converted into internal (intermediate) data, contour data extraction is performed. The contour data is extracted from the drawing data in the section 3 (S7), and the contour data shift section 4 determines the position where the contour line should be arranged with the reference point P as a reference. That is, the reference point P is added to the X (line direction) coordinate of each vector forming the contour line in the drawing data (S8). Next, the process waits for a print command (S9), and when there is a print command, print processing for one sheet (S10) is executed. The above processing is continued until printing is completed (S1)
1).

FIG. 3 is a diagram for explaining the operation of the present inkjet plotter. In the first drawing when the power is turned on, as shown in FIG.
Nozzles P1 and P2 of 0 are continuously used and the contour line 21
The vertical line is drawn, but in the drawing when the power is turned off and then turned on again, as shown in FIG. 3B, only the contour line 21 corresponds to one nozzle pitch Δx. Since it shifts to the left, the nozzles of the inkjet head 10 that draw the vertical line of the contour line 21 are P3, P.
4 is changed to prevent continuous use of P1 and P2. Note that the graphic 21 does not have a problem such as contour drawing, and therefore is drawn at the same position.

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 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 31, a contour line is generated by the contour data setting section 32 according to the input condition of the paper size input device 31, and the contour line is contoured. It is supplied to the data shift unit 4. Regarding the processing after the shift of the contour data supplied to the contour data shift unit 4,
It is similar to the first embodiment. According to this embodiment, since the contour line is given from the contour data setting unit 32, the operation of extracting only the contour line from the drawing data becomes unnecessary, and the process can be simplified accordingly.

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.

[0023]

As described above, according to the present invention, the nozzle position of the ink jet head that draws the contour line is changed every time the power is turned on. It can be shortened to several tenths to several tenths as compared with the conventional one. 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. Further, according to the present invention, since only the contour line is shifted,
The amount of data used for shift processing can be minimized, and the processing time can be shortened.

[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.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Input buffer, 2 ... Analysis part, 3 ... Contour data extraction part, 4 ... Contour data shift part, 5 ... Bitmap expansion processing part, 6 ... Frame buffer, 7 ... Controller, 8 ...
Paper transport unit, 9 ... Shift register, 10 ... Inkjet head, 11 ... Storage unit, 12 ... Power switch, 13 ...
Reference point changing unit, 21 ... Contour line, 22 ... Graphic, 31 ... Paper size input device, 32 ... Contour data setting unit.

Claims (4)

[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 ink jet recording apparatus including a sheet conveying means and an ink jet head for outputting the contour line and the figure on the recording sheet based on the drawing data sequentially read from the frame storing means, a power switch is turned on. Only the position of the contour line in the drawing data in the nozzle arrangement direction of the inkjet head for each An ink jet recording apparatus characterized by comprising a contour shift means for shifting. 2. The contour line in the drawing data is supplied from the outside together with the figure, and further comprises contour data extracting means for extracting only the contour line from the drawing data. The inkjet recording apparatus according to claim 1. 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 shift means shifts a storage position of the drawing data in the frame storage means.