JP4440673B2 - Control device for printer device - Google Patents

Description

  The present invention relates to a control apparatus for a printer apparatus that forms an image by ejecting ink while scanning an inkjet recording head.

In a printer apparatus having an ink jet recording head, it is well known that motor control is performed by an encoder. The main scanning encoder has been devised to prevent color misregistration for each nozzle due to uneven carriage speed and to generate print timing with no unevenness such as printing outside the constant speed range, but the accuracy of the absolute position is considered. Not.
As a technique related to a conventional encoder, for example, documents as shown in Patent Documents 1 to 10 are disclosed.
Among them, in Patent Document 1, an encoder is not mounted for the purpose of correcting the carriage position for main scanning, but means for reading print data is required.
In Patent Document 2, in order to prevent the positional deviation of the main scan, a plurality of sensors that read the linear scale of the encoder are provided to absorb the pitch error of the scale. Increases and increases costs. Also, no consideration is given to the positional information shift caused by noise on the encoder pulse.
In Patent Documents 3 and 4, in order to eliminate the misalignment of position information due to dirt on the encoder film, the non-detected part of the encoder is detected, the position count of that part is masked, and the skipped part is calculated. Although it was complemented, it is not considered to correct the error of the accumulated position count.
In Patent Document 5, control is devised so that the position in the main scanning direction is not affected by fluctuations in the encoder pulse, but it is merely virtual position information based on encoder pulse period measurement, and the absolute position is compared with the absolute position. Includes errors.
In Patent Document 6, position correction is performed on the basis of the position read by the optical sensor in order to correct the positional deviation due to the mechanical factor of the carriage, but the positional deviation due to the electrical factor (noise or the like) is corrected. Correction is not considered.
Patent Document 7 discloses a correction method in the case where reading is performed with the scale of the film skipped due to contamination of the encoder film. However, since correction is performed based on a count by a clock different from the encoder pulse, the time reference is used. is there.
Here, the disclosure of Patent Document 7 is not based on the absolute coordinate reference, and is ineffective in correcting the deviation with respect to the carriage moving speed unevenness. In addition, when an abnormality of the encoder film occurs, no consideration is given.
Patent Document 8 discloses a device for keeping the encoder film assembly position constant, but does not consider deformation of the film itself.
In Patent Documents 9 and 10, the accuracy of assembly is reduced by changing the method of the encoder device itself in which an interference fringe is projected instead of a film slit to generate a slit in the encoder device, and the secular change resistance is increased. Is disclosed. However, the cost is increased as compared with the conventional method, such as using laser light, and no consideration is given to guaranteeing the absolute position of the slit.
Also, in order to improve the carriage position accuracy in the main scanning direction, the pulse signal output from the encoder as the carriage moves is transparent so that pulses with a period different from normal are output periodically (during constant speed running). It has also been studied to provide slit patterns with different widths at regular intervals in the printed pattern of the encoder film.
By detecting the pattern mark, it is corrected to correct absolute position information. However, the influence of the deviation of the carriage home position has not been considered.
Further, a technique for correcting a variation due to a mechanical factor of the carriage home position has been studied, but detection of an assembly error or abnormality of the encoder film itself is not considered.
Further, Patent Documents 11 to 19 exist as related documents, but there is no disclosure regarding correction of the position fluctuation of the absolute position mark.
JP 2000-025291 A Japanese Patent Laid-Open No. 2001-20595 JP 2002-225374 A JP 2002-267495 A JP 09-254480 A Japanese Patent Laid-Open No. 09-240097 Japanese Patent No. 3041609 JP-A-10-226122 JP 07-318373 A Japanese Unexamined Patent Publication No. 08-035859 JP 2000-015794 A JP 2000-015795 A JP 2000-071438 A JP 2000-280555 A JP 2000-289253 A JP 2001-038895 A JP 2001-301163 A JP 2002-248810 A JP 2002-331655 A

As described above, there are various conventional documents, each of which includes features and disadvantages. In an ink jet printing apparatus, the carriage is moved and ink is ejected from nozzles provided on a head in the carriage, and an image is printed on a recording medium. Is obtained by counting the number of pulses obtained from the linear encoder, and generating and controlling the ink injection timing based on the pulse obtained from the linear encoder. It is common.
The pulse signal from the linear encoder is generated from information obtained by optically reading a slit pattern printed on a transparent encoder film provided in the carriage movement direction. The current position of the carriage can be known by counting the encoder pulses.
In order to prevent errors in the position information due to miscounting due to noise riding on this pulse, conventionally, the pulse signal output from the encoder as the carriage moves is periodically (during constant speed running). A slit pattern (hereinafter referred to as an absolute position mark) having a width different from normal is provided at regular intervals in the print pattern of the transparent encoder film so as to output pulses having a period different from normal.
It has been considered to improve the accuracy of the position information by detecting the absolute position mark and correcting the position count value of the integrated normal pulse based on the absolute position information.
However, when the carriage moves to the home position, it is common to move the carriage to a position where it cannot be moved mechanically (abut) and set that position as the home position. Is cleared to 0 at the home position.
Carriage position management is performed based on the home position. However, the stop position of the carriage is not always the same every time due to mechanical factors, and may be different each time. For this reason, there is a natural deviation from the absolute coordinates of the absolute position mark.
For this reason, a large shift due to a large mechanical factor occurs after the position correction by the absolute position mark from the home position, which greatly affects the print image quality. Due to a mechanical error that occurs when the encoder film is assembled, the absolute position mark provided with the film varies.
Conventionally, it has been proposed to correct a large shift due to mechanical factors of the absolute coordinates of the absolute position mark and the home position. Since the mechanical factor in this case is a minute shift due to machine fluctuations over time, error processing is performed due to the occurrence of an interrupt when a large shift due to contamination of foreign matter occurs.
In this case, it is conceivable that the encoder film assembly error has a large deviation from the carriage home position (compared to mechanical variation over time), and an error may occur in the initial state.
Therefore, in view of the above situation, the object of the present invention is to obtain information about the position of the absolute position mark provided on the encoder film in the main scanning encoder information acquisition, which is the basis of the carriage position control. Another object of the present invention is to provide a printer control device that detects and automatically corrects the position change of the absolute position mark due to temperature change or change with time, and prevents device breakdown due to carriage runaway due to an obstacle to the encoder film.

In order to solve the above-mentioned problem, the invention according to claim 1 is an ink jet recording head having nozzle rows arranged in the main scanning direction, and a plurality of first recording heads provided at a predetermined recording pitch on a scale. A linear encoder having a mark, a plurality of second marks provided at regular intervals on the scale, and a detection unit for detecting the first mark and the second mark, and the detection unit, A first encoder pulse that is mounted on the inkjet recording head and reciprocally moves, and detects and outputs the plurality of first marks by the detection unit by the linear encoder by the reciprocating movement of the carriage. the control device of the printer device for generating an ink ejection timing of the nozzle rows, receive encoder pulses from the linear encoder And a main scanning encoder pulse receiving unit that detects a deviation of the home position of the carriage from a second encoder pulse that is detected and output by the detection unit in the linear encoder. The main scanning encoder pulse receiving unit is configured to set a second mark period counter that counts a period of the plurality of second marks by the second encoder pulse, and an interval between the adjacent second encoder pulses. A second mark period difference calculation unit that calculates a difference between the count values of the two adjacent second encoder pulses counted by a reference clock different from the two encoder pulses, and the second mark period a calibration control unit and a second mark period difference holding unit that stores the obtained difference by calculating the difference calculation unit, key Storing Ribureishon Performed, if the calibration unexecuted is the second mark of the first from the home position coordinates and the carriage home position of the carriage in the second mark period difference computing unit and calibration information holding unit for storing the difference computed by counting the difference between the coordinates, in which example Bei a.
The invention according to claim 2, in the main scanning encoder pulse receiving unit, the home position offset calculating unit for calculating a positional deviation of the home position of the carriage, the plurality of second the carriage of the mark obtaining a correction value for the coordinate value of the first second mark from the coordinate values of the first second mark relative to the said home position and unique coordinate values with the home position of the first second mark The printer control device according to claim 1, further comprising a calibration correction control unit .
According to a third aspect of the present invention, in the main scanning encoder receiving unit, a second mark period variation calculating unit that obtains a variation of the difference with respect to the plurality of second encoder pulses is provided. It is a control device of the printer device .
Also, error if the invention according to claim 4, in the period difference calculating unit, the difference is a difference limit control unit for obtaining whether present within limits, where the difference is not within limits The control apparatus for a printer apparatus according to claim 2, further comprising: an interrupt generation unit that issues an interrupt as described above .

According to the present invention, since the assembly error of the main scanning encoder scale can coexist with the automatic position correction of the positional deviation due to the mechanical factor of the home position, the accurate second mark position can be maintained, and thus stable. Therefore, even if there is a physical abnormality with respect to the main scanning encoder scale , the presence or absence of a failure can be detected in advance, so that misprinting and equipment destruction can be prevented.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing the appearance of an ink jet printer. In the ink jet printer 15 shown in FIG. 1, the ink jet recording head 1 has a nozzle row in the head scanning direction (hereinafter referred to as the main scanning direction), and the ink tank is formed integrally or separately. At the same time, it is mounted on the carriage 2.
The carriage 2 reciprocates in the directions of arrows A and B along the guide rail 5 via the timing belt 4 by the moving motor 3. On the other hand, in order to synchronize with the movement of the carriage 2, a synchronization signal generating means is provided.
This is an optical encoder in which slits are drawn on a transparent film (not shown) at a recording pitch density corresponding to, for example, 180 dots / inch (dpi) or 360 dpi, and slits having different widths are drawn at regular intervals. The encoder 6 is fixed to the apparatus main body.
In order to detect the slit of the linear encoder 6, a detection unit 7 made of a photo interrupter or the like is mounted on the carriage 2 to enable position detection by movement of the carriage 2.
In addition, a flexible printed circuit board (not shown) for extracting an output signal from the photo interrupter to the outside is connected to the detection unit 7 body, and is connected to a circuit unit (not shown). The feeding roller 10 sandwiches the recording material 11 and feeds the recording material 11 in the D direction.
The recording material 11 fed by the feeding roller 10 is wound around the platen roller 8 and fed in the F direction. Further, the gap between the recording material 11 wound around the ink jet recording head 1 and the platen roller 8 is constant.
When the ink jet recording head 1 moves along the guide rail 5 to G (left end in the figure), the ink jet recording head 1 faces the head cleaning means 12 and is capped at the time of cleaning and storing the ink discharge nozzles.
In the inkjet recording head 1, a plurality of nozzle rows are arranged at a certain interval, and ink of each color is ejected from each nozzle to realize color printing. When moving once along the guide rail 5, the writing of the recording width d is completed.
FIG. 2 is a timing chart showing pulses output from the linear encoder 6. The upper part of FIG. 2 is the slit on the transparent film, and the pulse signal of the lower part is output by optical reading.
In this case, as shown in the figure, signals that are 90 degrees out of phase are also output simultaneously (referred to as A phase and B phase, respectively). This is used to detect whether the traveling direction of the carriage 2 is the forward or backward path of the reciprocating operation. Normally, the edge of the A-phase pulse is detected, the ink ejection timing is generated, and printing is performed.

FIG. 3 is a block diagram showing the control apparatus of the printer apparatus according to the present invention. In FIG. 3, the control device of the printer apparatus includes an encoder pulse receiving unit 21. The encoder pulse receiving unit 21 includes a transparent scale film 6a provided with an absolute position mark and a linear encoder 6 that outputs pulses, and software. The CPU 38 performs processing and interrupts, the main scanning cycle register 33 that controls the main scanning motor control unit 36 that performs carriage movement control, and the position correction unit 34a that performs counting and position correction with a trigger from the encoder pulse receiving unit 21. A main scanning position counter 34, a print timing generation unit 35 that generates a print timing from the main scan position counter value, and a head control unit 37 that controls a print operation from the print timing.
The encoder pulse receiving unit 21 includes a period measuring unit 22 that receives an output pulse of the linear encoder 6 and an absolute position mark determining unit 23 that outputs a mark to an absolute position mark up / down counter 24.
The encoder pulse receiving unit 21 also includes an absolute position mark cycle counter 39a, an absolute position mark cycle difference holding unit 39b, a calibration control unit 39 including an absolute position mark cycle difference calculating unit 39c, and an absolute position mark cycle variation calculation. Part 40 and calibration information holding part 41.
Further, the encoder pulse receiving unit 21 includes a carriage direction detection unit 27, an absolute position mark detection mask generation unit 28, an absolute position mark counter load control unit 25, an offset adder 26, and a calibration correction control unit 29a. The home position offset calculation unit 29, the offset limit control unit 31, the interrupt generation unit 30, the cycle difference limit control unit 42 are included, and the speed result load control unit 32 is included.

FIG. 4 is a timing chart showing an example of printing without noise. FIG. 5 is a timing chart showing an example of erroneous printing due to noise. FIG. 6 is a diagram for explaining position correction by an absolute position mark provided on a film pattern of a conventional encoder.
FIG. 4 shows a case where a normal encoder pulse is input from the main operation linear encoder 6 when there is no influence of noise. At this time, the value of the main scanning position counter 34 indicating the position of the carriage 2 is counted up in synchronization with the edge of the pulse.
Using this counter value as a position information base, an imprinting trigger signal for imprinting a designated dot (droplet color, size) at a designated position is generated by the print timing generation unit 35, and based on this signal, an imprinting signal is generated. Has been done.
In FIG. 4, printing is performed continuously, and dots are printed on the recording material 11 at equal intervals. Thereafter, if the movement of the carriage 2 is continued, encoder pulse input is also input, so that the position counter value continues to count up and the position information is accumulated.
FIG. 5 shows an example of a pulse waveform when noise is added to the encoder pulse. As shown in FIG. 5, pulse noise is present at two places. In this case, although noise removal control is provided in the encoder pulse receiving unit 21, it may not be removed depending on the pulse width.
As the movement of the position counter 34 at this time, the pulse noise edge is erroneously recognized as the rising edge of the encoder pulse as shown in FIG. Inevitably, the subsequent printing trigger signal also malfunctions, and extra printing is performed (in the figure, the hatched dots indicate the extra dots printed by noise).
Furthermore, since the position counter value is accumulated while including this noise deviation, the amount of positional deviation also increases each time noise is generated as the scanning is performed. For this reason, an absolute position mark is inserted, and the upper part of FIG. 6 shows an encoder film pattern in which a conventional absolute position mark is inserted.
As the base of the encoder slit, slits having a constant pitch and a constant width are provided, but slit patterns having different widths are inserted at constant intervals. For example, if the position counter 34 is composed of 16 bits, a different pattern is inserted in units of 8 bits (a position where all the lower 8 bits are all 0). The slits having different widths are called absolute position marks.
A combination pattern of narrow slits and wide slits is provided at regular intervals on the base pitch slits. In FIG. 6, it is composed of three narrow, wide and thin slits. The waveform output from the encoder using this film is as shown below.
Even when the encoder pulse cycle changes due to the speed change of the carriage 2, the operation of acceleration (thin) -deceleration (wide) -acceleration (thin) as shown in this mark pattern occurs in units of slits. It cannot be generated from responsiveness.
The fourth waveform from the top is the absolute position mark detection signal. After the absolute position mark is detected by the absolute position mark determination unit 23 from the third-stage encoder pulse period, the absolute position mark detection signal is obtained.
The detection signal is counted by the absolute position mark counter 24. At this time, the signal indicating the carriage moving direction from the B-phase input from the encoder 6 is the signal shown in the fifth stage.
The absolute position mark counter 24 is counted by the absolute position mark detection signal. At this time, the up-count or down-count is selected by the logic of the aforementioned carriage direction signal shown in the fifth stage.

In FIG. 6, marks are inserted every 1000 counts, and the absolute position mark counter 24 counts up or down by 1000 (sixth stage). The absolute position load control unit 25 generates an absolute position mark strobe signal (seventh stage) from the absolute position mark detection signal (shifted after the absolute position mark is counted by the flip-flop).
In FIG. 6, the movement of the main scanning position counter 34 is shown in the lowermost stage, and a portion with a diagonal line pointing downward to the right is a position count value that has malfunctioned due to noise or the like, or includes a misalignment due to malfunction.
Then, the value of the absolute position mark counter 24 is loaded into the position counter 34 by the absolute position mark strobe signal. According to FIG. 6, in the first correction, a value n (or m) is loaded into the position counter 34 and the deviation of 5 counts is corrected.
A conventional correction operation based on the home position will be described with reference to FIG. In FIG. 6, the uppermost waveform is the main scanning encoder pulse. It shows how the carriage accelerates from a stopped state. The above-mentioned absolute position mark is inserted around the low-speed region in the waveform.
The value of the position counter is shown in the second stage. A state where no encoder pulse edge is input indicates the home position, and the counter value is cleared to zero.
Thereafter, as the carriage moves, it is counted up by the edge of the encoder pulse.
When the absolute position mark is detected, the absolute position mark counter 24 is counted up as described above, and the value of the position counter 34 is corrected from the value. At this time, the value of the absolute coordinate determined from the absolute position mark is fixed, but the value 0 of the home position is simply a state where the carriage 2 is stopped.
This stopped state is a position where the carriage 2 does not move even when a manipulation amount is physically applied in the minus direction. Naturally, this position includes a minute error. If the carriage 2 is stopped by abutting, it can be considered that the carriage 2 returns slightly due to the reaction.
If this error exceeds the slit width provided in the encoder film, an error appears in the value of the position counter 34.
Therefore, even if the position to be corrected by the absolute position mark in FIG. 6 is n, the position of the absolute position mark even if the encoder pulse is correctly counted (no influence of noise) when viewed from the home position 0. Is not necessarily n.
6, the absolute position mark is counted down to the home position side as the position of n. In this example, the value of the position counter 34 at the home position is 4. This value is the difference between the home position and the position of the absolute position mark, that is, the offset.
This value is equal to the difference between the absolute position of the first absolute position mark from the home position and the position counter value immediately before that + the position occupied by the absolute position mark. When the absolute position mark counter = 1, the home position offset value can be obtained by performing the above calculation.

FIG. 7 is a diagram illustrating a correction example of the coordinates of the absolute position mark based on the home position. In FIG. 7, the unique coordinate value of the first absolute position mark is n, and the difference from the home position reference coordinate (value of the position counter 34) is α.
In the conventional correction, when the value of α exceeds a predetermined value (offset limit), an interruption is generated as a home position error and error processing is performed.
In the example of FIG. 7, when the offset limit value is 5 and 5 <α <25 (25 will be described later), the coordinate obtained by adding this α to the coordinate value n of the absolute position mark is corrected after the home position reference is corrected. Use absolute position coordinates. The correction value α is stored in the calibration information holding unit 41 in FIG. 3 and is always added to the absolute position mark coordinates during normal operation.
Thus, when the home position reference absolute position counter coordinate is α, encoder film abnormality occurs when α> 25. If calibration has been performed and 5 <α <25, the home position is abnormal.
If calibration has been performed and 0 <α <5, the home position position is to be corrected. If calibration has not been performed and 0 <α <25, the calibration result is stored.
FIG. 8 is a flowchart for explaining the flow of calibration. 3 and 8, when the power of the device (printer device) is first turned on, the calibration control unit 39 in FIG. 3 refers to the calibration execution history in the calibration information holding unit 41 (S1).
The calibration information holding unit 41 is provided with a calibration execution flag. In the initial state, an unexecuted flag is set. If it is not performed (S2), the calibration is executed and the flag is already executed. Rewrite to The flow up to this point is the first condition determination part of FIG.
As shown in FIG. 8, the calibration is performed by moving the carriage (S3). At this time, the coordinates of the absolute position mark are corrected based on the home position (S4).
The correction example at this time has been described above with reference to FIG. 7. Again, in FIG. 7, the unique coordinate value of the first absolute position mark is n, and the difference from the home position reference coordinate (position counter value) is α. And
When the absolute position mark coordinates include an encoder film assembly error, calibration is performed, home position reference offset calculation is performed (S5), and the absolute position mark is stored in the calibration information holding unit 41 (S6). ).
It is determined whether the offset limit is over (S7). If the limit is over, an error flag is turned on (S8), an interrupt is generated (S9), and the calibration execution sequence is terminated.
In the conventional home position reference correction, an encoder film assembling error can also be corrected, the correction information is stored in the calibration information holding unit 41, and the absolute position mark coordinates can be automatically corrected by one calibration.

FIG. 9 is a timing chart for explaining an example of holding the absolute position mark cycle difference. In the calibration execution, the following control is performed on the assumption that the carriage is traveling at a constant speed between the absolute position marks.
In FIG. 9, the uppermost stage is an encoder film pattern, and absolute position marks are inserted at regular intervals. The second stage below is an encoder output pulse, and the third stage is an absolute position mark detection signal, which is detected for each absolute position mark.
The fourth stage shows the value of the absolute position mark period counter 39a of the present invention. This absolute position mark period counter 39a does not count encoder pulses, but counts another reference clock, and a clock whose resolution can be counted more finely than a normal position counter is provided.
The absolute position mark cycle counter 39a is cleared every time a mark is detected, and the value before the clear is calculated by the absolute position mark cycle difference calculation unit 39c in FIG. The difference is stored in the absolute position mark cycle difference holding unit 39b.
The lower two stages of FIG. 9, ie, the fifth and sixth stages, show the difference calculation result and its temporary holding, and are finally written in the absolute position mark cycle difference holding unit 39b in the nonvolatile memory. The writing to the absolute position mark cycle difference holding unit 39b occurs only when calibration is executed.
The main scanning encoder film is usually attached in a state of being stretched in a straight line by fixing both ends, but it is conceivable that the main scanning encoder film is deformed due to a temperature change in the apparatus or a change with time. This deformation also changes the physical position of the absolute position mark provided on the film.
Naturally, if the position of the absolute position mark fluctuates, the ink ejection position also fluctuates, which adversely affects the image quality. Therefore, according to the above, the initial state before the film deformation can be held as data.
The calibration control unit 39 is provided with an absolute position mark cycle counter 39a, a cycle difference calculation unit 39c, and an absolute position mark cycle difference holding unit 39b that count the cycle of the absolute position mark with a clock pulse different from the encoder pulse. Is done. Thereby, the positional relationship of the absolute position marks on the encoder film at the time of calibration can be held with a small amount of data.
Thereby, the positional relationship of the absolute position marks on the encoder film at the time of calibration can be held with a small amount of data. The difference between the held absolute position marks indicates the pitch of the encoder film in the initial state, and becomes a determination criterion when the encoder film is deformed.

FIG. 10 is a flowchart for explaining the flow of position fluctuation detection based on the absolute position mark cycle difference including calibration. In FIG. 10, a calibration execution sequence is performed (S11).
When detecting the absolute position mark during the normal operation, as described above, the absolute position mark period counter 39a calculates the period difference between the absolute position marks as in the calibration (S12).
The absolute position mark cycle counter 39a is cleared (S13), the absolute position mark cycle difference at the time of calibration stored in the calibration information holding unit 41 is read out (S14), and the current calculation result is compared with the cycle difference. The position variation of the absolute position mark is obtained by calculating the difference (S15).
Next, it is determined whether or not the offset limit is over (S16). If the limit is over, an error flag is turned on (S17), an interrupt is generated (S18), and the calibration execution sequence is terminated. That is, when the fluctuation exceeds a preset period difference limit value, it is considered that the encoder film is abnormal, and an interrupt is generated to perform error processing.
The main scanning encoder pulse receiving unit 21 is provided with an absolute position mark cycle variation calculating unit 40 to detect the position variation of the absolute position mark due to the aging of the encoder film.
Thus, even in the normal operation after calibration, the position information between the absolute position marks on the current encoder film is acquired and held by the absolute position mark period counter 39a and the absolute position mark period difference calculation unit 39c. The variation can be known from the position information of the absolute position mark on the encoder film at the time of calibration.
Even if the fluctuation is within the limit, the fluctuation is accumulated from the reference value at the time of calibration, so error processing is performed when the limit is exceeded even during aging, and sudden fluctuation (abnormal) Immediate error handling.
The limit value is set at a level that affects the normal image quality, but is set in consideration of the accuracy of the counter and the encoder output accuracy. Here, even if there is a change in the physical position of the absolute position mark due to deformation of the encoder film or the like, there is no change in the value of the position counter itself because there is no change in the number of slit patterns.
However, in the print resolution, it is necessary to previously determine and set the above-described period difference limit value from the viewpoint of the limit of the positional deviation of the level that affects the image quality. Therefore, it is preferable that the resolution of the absolute position mark period counter 39a is set as fine as possible than the printing resolution.
As mentioned above, the encoder film is only mechanically fixed, so if the film becomes dirty, damaged, or sagging due to vibration or impact on the device or an unexpected failure, it will function normally as a device. It is possible that it will not work.
In the worst case, the carriage 2 may run away, leading to equipment destruction. Therefore, to avoid such an unexpected situation, the carriage 2 is stopped and the period difference limit control unit is notified to the period difference calculation unit to notify the abnormality. 42 and an interrupt generation unit 30 are provided.
This makes it possible to determine the correctness of the absolute position mark position from the fluctuations in the absolute position mark cycle difference, and when fluctuations or abnormalities affecting the image quality are recognized, error processing is performed when an interrupt occurs, resulting in failed printing or carriage runaway Can prevent the destruction of the equipment.

It is a perspective view which shows the external appearance of an inkjet printer. It is a timing chart which shows the pulse which a linear encoder outputs. FIG. 3 is a block diagram illustrating a control device of the printer device according to the present invention. It is a timing chart which shows the example of printing without noise. 6 is a timing chart illustrating an example of erroneous printing due to noise. It is explanatory drawing of position correction by the absolute position mark provided in the film pattern of the conventional encoder. It is explanatory drawing which shows the example of a correction | amendment of the coordinate of the absolute position mark of a home position reference | standard. It is a flowchart explaining the flow of calibration. It is explanatory drawing which shows the holding example of an absolute position mark period difference. It is a flowchart explaining the flow of the position variation detection by the absolute position mark period difference including calibration.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet recording head 2 Carriage 6 Main scanning linear encoder 15 Inkjet printer 21 Main scanning encoder pulse receiving part 25 Absolute position mark load counter control part 26 Offset adder 28 Absolute position mark detection mask generation part 29 Home position offset calculating part 29a Calibration Correction control unit 30 Interrupt generation unit 31 Offset limit control unit 39 Calibration control unit 39a Absolute position mark cycle counter 39b Absolute position mark cycle difference holding unit 39c Absolute position mark cycle difference calculation unit 40 Absolute value mark cycle variation calculation unit 41 Calibration Information holding unit 42 Period difference limit control unit

Claims (4)

An inkjet recording head having nozzle rows arranged in the main scanning direction, a plurality of first marks provided at a predetermined recording pitch on the scale, and a plurality of second marks provided at regular intervals on the scale. A linear encoder having a mark, a detection unit for detecting each of the first mark and the second mark, and a carriage on which the detection unit and the inkjet recording head are mounted and reciprocally moved. In the control device of the printer device that generates the ink discharge timing of the nozzle row from the first encoder pulse that is detected and output by the detection unit at the linear encoder by the reciprocal movement of the nozzle row ,
The encoder pulse from the linear encoder is received, and the home position of the carriage is detected from the second encoder pulse output by detecting and outputting the plurality of second marks by the detection unit at the linear encoder. A scanning encoder pulse receiver,
The main scanning encoder pulse receiving unit,
A second mark period counter that counts the period of the plurality of second marks by the second encoder pulse, and an interval between the adjacent second encoder pulses different from the second encoder pulse. A second mark cycle difference calculation unit that calculates a difference between the count values of each of the two adjacent second encoder pulses counted by a clock and is calculated by the second mark cycle difference calculation unit. A calibration control unit having a second mark period difference holding unit for storing the difference;
The calibration completion is stored, and when the calibration is not executed, the second mark cycle difference calculation unit calculates the coordinates of the carriage home position and the first mark of the second mark from the carriage home position. A calibration information holding unit for storing the difference calculated by counting the difference from the coordinates ;
The printer controller and wherein further comprising a. In the main scanning encoder pulse receiving unit, the home position offset calculating unit for calculating a positional deviation of the home position of the carriage, with the first second mark from the home position of the carriage of the plurality of second marks characterized in that a calibration correction controller from said coordinate value of the first second mark relative to the said home position and unique coordinate values to obtain the corrected value for the coordinate value of the first second mark The control apparatus for a printer apparatus according to claim 1. 2. The control device for a printer apparatus according to claim 1, wherein the main scanning encoder receiving unit is provided with a second mark cycle variation calculation unit that obtains the variation of the difference with respect to the plurality of second encoder pulses . The period difference calculating unit, the difference is a difference limit control unit for obtaining whether present within limits, the difference is provided an interrupt generator for an interrupt as error if it is not in a limit value the control device of the printer apparatus according to claim 2, wherein a.

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