JP2005313331A - Recorder with means for taking counter measure against abnormality of positional information - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recorder capable of detecting positional information of a specific carriage where noise enters a signal for controlling scanning of the carriage relatively easily and accurately. <P>SOLUTION: A carriage 1 performs scanning at a constant speed over the entire movable region (step S100), an encoder signal is taken in (step S101) and noise judgment is carried out (step S102). If the encoder signal is judged abnormal as a result of judgment (step S102/NO), position information of carriage is stored temporarily (step S103) and if that scanning is preset n-th scanning (step S104/YES), the positional information stored temporarily at step S103 is compared. If it has reproducibility as a result of judgment (step S105/YES), it is recorded as a noise generation range (step S106). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet recording apparatus used in a printer apparatus, a copying apparatus, and a facsimile apparatus.

In a conventional recording apparatus, in an apparatus for forming an image by scanning a carriage on which a recording head is mounted, the recording apparatus is provided with detection means such as an encoder scale and an encoder sensor in order to control carriage scanning. Further, if an error occurs in the position information detected by the detecting means, the recorded image quality is affected. Many means for detecting these noises are known in the prior art.

The noise that causes the position information error includes noise that occurs suddenly electrically and mechanically, and noise that occurs constantly or frequently within a specific range due to dirt, scratches, wear, etc. on the encoder scale. Among these, there is known a means for recording the range of noise generated in a specific range and using it for subsequent countermeasures.
However, it is difficult to determine whether the two causes are separated based on only information during normal operation due to inconsistencies in operating conditions, such as differences in scanning speed and acceleration, passage of time, and environmental changes. It leads to lack of.

Known documents and techniques most similar to the present invention include the following.
Patent Document 1 “Encoder Abnormality Detection Method” describes an encoder abnormality detection method.
Patent Document 2 “Image Forming Apparatus” describes a sub-scanning direction deviation correction of a plurality of heads and a line sensor in the main scanning direction.
Patent Document 3 “Method and Apparatus for Determining Appropriateness of Detection of Encoder Slits” describes a system that makes an abnormality when the carriage is reciprocated and the zero point is shifted. In this method, the position of occurrence of an abnormality is unknown, but it can also be said to be an abnormality detection mode.
Patent Document 4 “Image Forming Apparatus” describes a means for obtaining speed and position information of a rotating body and a drive control unit for controlling a drive motor based on information from this means.
Unlike these inventions, the present invention is characterized in that it has a mode for detecting an abnormal part, and as a specific method thereof, means for reading a print pattern with a line sensor and means for avoiding after abnormality detection Is also shown specifically.

JP 2001-289670 A JP 2002-264320 A Japanese Patent Laid-Open No. 11-23323 JP 2002-108169 A

  The present invention has been made in view of such a problem, and in an apparatus that forms an image by scanning a carriage on which a recording head is mounted, a signal for controlling carriage scanning is detected when the carriage is scanned. It is an object of the present invention to provide a recording apparatus capable of detecting specific carriage position information including a relatively easy and accurate information.

In order to solve the above problems, the present invention has the following features.
The recording apparatus according to claim 1, wherein the recording apparatus performs recording by ejecting ink onto a recording medium while reciprocating a recording head according to an ink jet system including a plurality of recording elements.
Scanning means for reciprocating scanning of the recording head, position detecting means for detecting position information of the recording head, detection means for detecting a specific range where abnormality occurs in the position information data, and position information detection abnormal range detection It has the mode for.
The recording apparatus according to claim 2, wherein the position information detection abnormal range detecting means reads a pattern recorded on the recording medium with a sensor, and detects a position based on an error between a position to be recorded and an actually recorded position. An information detection abnormality range is detected.
According to a third aspect of the present invention, the pattern reading sensor is fixed on a carriage together with the recording head.
According to a fourth aspect of the present invention, the pattern reading sensor is a line sensor that can read the main scanning direction.
According to a fifth aspect of the present invention, the pattern further includes a linear or curved line or boundary line extending substantially in the sub-scanning direction at equal intervals or at known intervals.

The recording apparatus according to claim 6 is characterized in that the position information detection abnormal range detection mode can be selected and executed by a user.
The recording apparatus according to claim 7, further, the position information detection abnormal range detection mode is automatically executed when there is a suspicion of abnormality during normal operation, or prompts the user to execute the position information detection abnormal range detection mode. It is characterized by that.
In the recording apparatus according to claim 8, the position information detection abnormal range detection mode is automatically executed when a predetermined period, for example, time, the number of recorded sheets, the amount of ink used, etc., has elapsed. Or prompting the user to execute.
In the recording apparatus according to claim 9, when a specific range in which an abnormality always or frequently occurs in the position information data is detected by the position information detection abnormality range detection mode, an abnormality occurrence range is determined in subsequent operations. Then, an alternative means that does not use position information is used.
The recording apparatus according to claim 10 is characterized in that the alternative means is a means for artificially creating and using a predicted signal in the abnormality occurrence range.

The recording apparatus according to claim 11, further comprising a plurality of sensors for detecting the position information, wherein the alternative means detects an abnormality occurrence range in one of the abnormality occurrence ranges. Is a means of complementing with other sensor information.
The recording apparatus according to a twelfth aspect of the present invention is further characterized in that the plurality of sensors for detecting the position information are installed with their positions shifted in the scanning direction.
According to a thirteenth aspect of the present invention, the recording apparatus further includes means for displaying that there is an abnormality in the detection of the position information while the substitution means is performed.

As described above, according to the means for solving the above problem, the recording apparatus of the present invention compares the generation range of noise that occurs constantly or frequently in a specific range due to contamination, scratches, wear, etc. of the encoder scale. Therefore, it is possible to easily and accurately detect.
Furthermore, in the recording apparatus of the present invention, it is possible to confirm the presence or absence of a noise generation range before the user recognizes an abnormality.
Furthermore, since the recording apparatus of the present invention can complement the encoder signal in the noise generation range, when the noise generation range is confirmed, the recording apparatus continues to be used without completely stopping the function of the recording apparatus. It becomes possible.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a diagram illustrating a configuration of an ink jet recording apparatus.
The ink jet recording apparatus includes a carriage 1, a main scanning motor 2, a sub-scanning motor 3, a conveyance belt 4, a guide lot 5, a conveyance roller 6, a tension roller 7, a recording head 8, a sheet 9, and an encoder scale 10.
In the ink jet apparatus, the carriage 1 is slidably held in the main scanning direction by the guide rod 5 which is a guide member horizontally mounted on the left and right side plates (not shown), and the main scanning motor 2 passes the timing belt (not shown) in the direction of the arrow. Move and scan in the (main scanning direction). Further, an encoder scale 10 having a slit for detecting the position of the carriage 1 in the main scanning direction (position relative to the home position) and an encoder sensor (not shown) are provided.
The carriage 1 includes a recording head 8 composed of four ink jet heads for ejecting ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (BK). They are arranged in a direction crossing the scanning direction, and are mounted with the ink droplet ejection direction facing downward.

On the other hand, a transport belt 4 for electrostatically attracting and transporting the paper 9 is provided as a transport unit for transporting the paper 9 as a recording medium below the recording head 8.
Here, the conveyance belt 4 is an endless belt, and is stretched between the conveyance roller 6 and the tension roller 7, and the conveyance roller 6 is opened from the sub scanning motor 3 via a timing belt and a timing roller (not shown). By doing so, it is configured to circulate in the arrow direction (belt (paper) conveyance direction).

Next, the outline of the control unit 26 of the ink jet recording apparatus will be described with reference to FIG.
The control unit 26 includes a drive signal generation circuit 24, a main control unit 25, a ROM 16, a RAM 17, and the like. From the control unit 26, through the interfaces 19 and 23, a motor driver 22 for driving the main scanning motor 2 and the sub scanning motor 3, a high voltage circuit 20 for applying a high voltage to the charging roller 21, and a recording head. A signal to a head driver 11 (comprising a head driving circuit and a driver IC) for driving 8 is output.

Next, the processing operation of the recording apparatus of the present invention will be described with reference to FIG.
First, the carriage 1 is scanned at a constant speed over the entire carriage movable region (step S100). During this time, the encoder signal is captured (step 101) and noise determination is performed (step S102). Here, the abnormality of the encoder signal is determined. When it is determined in the noise determination that the encoder signal is abnormal (step S102 / NO), the carriage position information is temporarily stored (step S103). When the scanning is completed, it is determined whether the scanning is the preset number of times n (step S104), and if not the number of times (step S104 / NO), scanning and determination are performed again (step S100). If it is the nth time (step S104 / YES), the position information temporarily stored in step S103 is compared to determine whether the noise generation is reproducible (step S105). If it is determined (step S105 / YES), it is recorded as a noise generation range (step S106).

Here, the number n is a number for separating the sudden noise from the reproducible noise, and is an arbitrary integer, preferably about 2 to 3 times. The location where the noise generation range is recorded may be recorded on a non-volatile memory mounted in the recording device, a removable recording medium, or a host PC.
By adopting the above method, the noise generation range has been measured in normal operation, so there is a problem that the measurement becomes relatively difficult. Thus, the noise generation range can be specified more accurately.

Further, another example of the noise generation range specifying means will be described with reference to FIG.
First, the carriage 1 is driven, and a noise generation range specifying pattern is printed on the entire area or a part of the area that can be recorded on the recording medium (step S107). Next, this is read by a sensor (step S108), and it is determined whether there is a deviation between the target pattern and the actually printed pattern (step S109). If there is a deviation (step S109 / YES), In terms of the position where the noise is generated, a range where noise is considered to be generated is specified, and this is recorded in the same manner as in step 106 (step S110). This operation can be repeated a plurality of times to increase the detection accuracy.
By adopting the above method, a more objective confirmation can be made by reading the abnormalities from the recorded results, compared to the conventional measurement method based on encoder signals that may be affected by noise. It becomes like this.

  Further, the location of the reading sensor may be a device that functions as a scanner that is merged with this device or that is prepared separately, or a sensor that is mounted on a carriage in this device. Also good.

  The reading sensor is preferably a line sensor 27 attached on the carriage 1 and extending in the main scanning direction as shown in FIG. The reading resolution of the line sensor 27 is preferably equal to or higher than the resolution of the encoder scale. The line sensor 27 can also be used for other purposes, for example, the purpose disclosed in Patent Document 2.

The pattern to be printed on the recording medium is a pattern including a straight line or a curved line or boundary line extending in the sub-scanning direction at equal intervals or at known intervals. It is desirable that straight lines and rectangles extending in the sub-scanning direction are arranged at equal intervals as shown in FIG. A plurality of colors may be mixed.
In this configuration, the operation of step S109 is performed by scanning the carriage 1 and measuring the interval between adjacent lines or boundary lines with the line sensor 27 while scanning the pattern 28A or 28B, and this is the interval at which printing is attempted. If it is larger or smaller than that, it is determined that skipping or double reading of the encoder sensor has occurred in that range. Further, by performing this operation several times while shifting the pattern to be printed in the main scanning direction, it is possible to narrow the abnormality occurrence range. This pattern can also be used simultaneously for other purposes, such as nozzle missing check.

  The noise generation range detection operation described above may be selected and executed by the user using an input unit such as a switch mounted on the apparatus or designation from the host PC.

  In addition, the noise generation range detection operation is automatically executed or is executed when it is determined that noise is included in the encoder signal by a method including a technique known as a conventional technique during a normal operation. The user may be encouraged to do so.

In addition, the noise generation range detection operation is automatically executed at a time when a predetermined period, for example, time, the number of printed sheets, the amount of ink used, or the like has elapsed, or the user is prompted to perform the operation. good.

When the noise generation range is recorded by the noise generation range detection operation, the encoder signal in the noise generation range is not used in the subsequent operations. As a result, when noise has occurred in the encoder signal due to contamination of the encoder scale, it has been necessary to continue using the image while affecting the image or to stop using it. And you can continue to use it.
Further, when this means is used, if necessary, productivity and recorded image quality, specifically, recording speed and ink droplet ejection resolution can be limited. In addition, by changing the operation as described above, it is possible to select the user's intention by requesting confirmation from the user on the host PC.

One alternative for not using an encoder signal in the noise generation range is shown.
Position information and speed information are used for scanning control of the carriage 1, but only speed information is obtained by performing only scanning at a constant speed without performing positioning, acceleration, or deceleration in the noise generation range. It becomes possible to control with. In this state, by using the speed targeted for control or the speed immediately before entering the noise generation range as an alternative to the speed information in the noise generation range, the speed information including errors due to noise is not used. To do. Further, when the position is out of the noise generation range, the positional information is corrected to a value obtained by adding the distance of the noise generation range to the position immediately before entering the noise generation range, thereby correcting the positional information shift. Further, when the rising edge of either phase of the encoder signal is used as the ink droplet ejection timing, the noise is usually input as the encoder signal 29 in FIG. If the abnormal signal 31 generated in the generation range is on, the pseudo signal generated so that the ejection timing 33 in the noise generation range has the same phase and the same period as one to several pulses immediately before the noise generation range. By using 32, it is possible to eliminate the influence of noise from the discharge timing.

As an alternative means not to use the encoder signal in the noise generation range, another example will be shown with reference to FIG.
In a configuration in which two encoder sensors 34A and 34B mounted on the carriage 1 detect position and speed information with reference to the encoder scale 10, information from the encoder 34A is normally used. When the noise generation range 35 on the encoder scale 10 is viewed, it is possible to eliminate the influence of noise by using information from the encoder sensor 34B. Here, three or more encoder sensors may be installed.

  In addition, it is more effective to install the encoder sensor at a distant position in the sense that an abnormal range on the encoder scale is avoided. desirable.

  It should be noted that during the period when the alternative means for not using the encoder signal within the noise generation range described above is used, the encoder signal is in an abnormal state and maintenance such as cleaning or repair is necessary. It is also possible to display a message on the host PC or the recording device, or notify the recording device with light, sound, or the like.

1 is a schematic configuration diagram of an ink jet recording apparatus showing an embodiment of the present invention. It is a schematic explanatory drawing of the control part of the inkjet recording device which shows one Example of this invention. It is a flowchart explaining the processing operation of the recording apparatus of this invention. It is a flowchart explaining another specific means of a noise generation range. It is a figure for demonstrating the pattern printed on a recording medium. It is drawing for demonstrating one of the alternative means for not using the encoder signal in the noise generation range. It is drawing for demonstrating another example as an alternative means for not using the encoder signal in the noise generation range.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Carriage 2 Main scanning motor 3 Sub scanning motor 4 Conveying belt 5 Guide lot 6 Conveying roller 7 Tension roller 8 Recording head 9 Paper 10 Encoder scale 16, 19, 23 Interface 26 Control part
27 Line sensor 28A, 28B Pattern 29, 30 Encoder signal 31 Abnormal signal 32 Pseudo signal 33 Discharge timing 34A, 34B Encoder sensor 35 Noise generation range

Claims (13)

A recording apparatus that performs recording by ejecting ink onto a recording medium while reciprocating a recording head according to an ink jet system including a plurality of recording elements,
Scanning means for reciprocally scanning the recording head;
Position detection means for detecting position information of the recording head;
Detection means for detecting a specific range in which abnormality occurs in the position information data;
Has a mode to detect the location information detection abnormal range
A recording apparatus. The detection unit reads a pattern recorded on a recording medium by a sensor, and detects a position information detection abnormal range from an error between a position to be recorded and an actually recorded position. Recording device. The recording apparatus according to claim 2, wherein the pattern reading sensor is fixed on a carriage together with the recording head. The recording apparatus according to claim 2, wherein the pattern reading sensor is a line sensor that can read a main scanning direction. The recording apparatus according to claim 2, wherein the pattern includes a straight line or a curved line or a boundary line that extends substantially in the sub-scanning direction at equal intervals or at known intervals. The recording apparatus according to claim 1, wherein the position information detection abnormal range detection mode can be selected and executed by a user. The position information detection abnormal range detection mode is automatically executed when there is a suspicion of abnormality during normal operation.
The recording apparatus according to claim 1, further urging the user to execute the recording apparatus. The position information detection abnormal range detection mode is automatically executed when a predetermined period has elapsed.
The recording apparatus according to claim 1, further urging the user to execute the recording apparatus. In the position information detection abnormal range detection mode, when detecting a specific range where abnormality always or frequently occurs in the position information data,
In the subsequent operations, in the abnormality occurrence range, an alternative unit that does not use position information is used. The recording apparatus according to any one of claims 1 to 8. The recording apparatus according to claim 9, wherein the substitute unit is a unit that artificially creates and uses a predicted signal in an abnormality occurrence range. A recording apparatus having a plurality of sensors for detecting the position information,
The recording apparatus according to claim 9, wherein the substitute means is means for complementing with another sensor information when one of the sensors in the abnormality occurrence range detects the abnormality occurrence range. The recording apparatus according to claim 11, wherein the plurality of sensors for detecting the position information are installed with positions shifted in a scanning direction. The recording apparatus according to any one of claims 9 to 12, further comprising means for displaying that there is an abnormality in detection of position information while performing the substitute means.

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