Patent Publication Number: US-7213900-B2

Title: Recording sheet and image recording apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a Continuation Application of PCT Application No. PCT/JP02/12828, filed Dec. 6, 2002, which was not published under PCT Article 21(2) in English. 
    
    
     This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2001-373002, filed Dec. 6, 2001, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to image recording apparatuses such as a printer, facsimile machine, and copying machine, particularly to a recording sheet in which distortion of an image recorded by an image recording apparatus using a plurality of recording heads to increase a recording width is corrected and to image recording apparatus using this recording sheet. 
     2. Description of the Related Art 
     An image recording apparatus of a photosensitive recording system, thermal transfer recording system, ink jet recording system or the like has been used in image recording apparatuses such as a printer and a copier machine. A recording head in which a large number of recording devices for recorded dots are linearly arranged at equal intervals is used in these recording systems. 
     Preparation of a recording head having a large recording length has a problem that yield becomes worse and cost increases with a larger length, and it has been proposed that a recording width be extended using a large number of recording heads. For example, in Jpn. Pat. Appln. KOKAI Publication No. 6-255175, a method has been described in which a plurality of recording heads are linearly arranged in such a manner that end portions of the heads overlap with each other to a certain degree. A position from which the recording head is to be switched in supplying an image signal to each recording head is irregularly set for each scanning line with respect to a region where the recording devices are redundant, so that joints become inconspicuous and the recording heads are easily arranged. 
     Moreover, in Jpn. Pat. Appln. KOKAI Publication No. 10-115955, a method and an image recording apparatus have been described in which to form a color image by a plurality of recording heads, a positional shift of each recording head is corrected to obtain an image having a satisfactory image quality from Moire fringes produced by superimposing test patterns formed by the respective recording heads. 
     Furthermore, in Jpn. Pat. Appln. KOKAI Publication No. 2000-25214, a method is described in which synchronization is controlled in a case where a width direction of a page is divided to perform printing by a plurality of recording heads. 
     According to conventional art, positional shifts of recorded dots of different colors printed in the same position of a recording sheet, and positional shifts of recorded dots of connection portions between recording heads adjacent in a width direction can be corrected. However, when a plurality of recording heads are connected to each other to expand a recording width, and arrangement of dots recorded by the respective recording heads shifts from a straight line, the recorded image is also distorted, but this cannot be corrected. 
     BRIEF SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a recording sheet and an image recording apparatus for correcting arrangement of recorded dots to record an image without any distortion in image recording in which a plurality of recording heads are connected to each other to constitute a recording head substantially having a large recording width. 
     According to a first aspect of the present invention, there is provided a recording sheet for use in an image recording apparatus which forms an image by a recording head, the recording sheet having a pattern for measurement in which a correction amount for correction of a positional shift of a recorded dot recorded by the recording head is measurable based on a positional relationship with an image for measurement formed by the recording head. 
     In this constitution, the pattern for measurement is disposed in which the correction amount for the correction of the positional shift of the recorded dot recorded by the recording head is measurable based on the positional relationship with the image for measurement formed by the recording head, and therefore the recorded dot positional shift can be corrected. The present constitution corresponds to first to fourth embodiments described later. 
     Moreover, a recording sheet according to a second aspect of the present invention relates to the recording sheet according to the first aspect of the present invention, and the pattern for measurement is formed in a color different from that of the image for measurement. 
     In this constitution, since the pattern for measurement is formed in the color different from that of the image for measurement, a positional relationship between the pattern for measurement and the image for measurement can be easily grasped. The present constitution corresponds to the first embodiment described later. 
     Furthermore, a recording sheet according to a third aspect of the present invention relates to the recording sheet according to the first aspect of the present invention, and the pattern for measurement is formed in a plurality of colors. 
     In this constitution, since the pattern for measurement is formed in the plurality of colors, the positional relationship between the pattern for measurement and the image for measurement can be easily grasped. 
     Additionally, a recording sheet according to a fourth aspect of the present invention relates to the recording sheet according to the first aspect of the present invention, and the pattern for measurement is formed in a line width different from that of the image for measurement. 
     In this constitution, since the pattern for measurement is formed in a line thinner than that of the image for measurement, the positional relationship between the pattern for measurement and the image for measurement can be easily grasped. The present constitution corresponds to the first embodiment described later. 
     Moreover, a recording sheet according to a fifth aspect of the present invention relates to the recording sheet according to the first aspect of the present invention, and the pattern for measurement comprises repetition of a basic shape pattern. 
     In this constitution, since the pattern for measurement comprises the repetition of a basic shape, and the positional relationship between the pattern for measurement and the image for measurement is measured a plurality of times to obtain an average value, precision of measurement can be enhanced. The present constitution corresponds to the first embodiment described later. 
     Furthermore, a recording sheet according to a sixth aspect of the present invention relates to the recording sheet according to the first aspect of the present invention, and the pattern for measurement comprises a stripe pattern including a plurality of straight lines having different intersection angles with respect to a direction in which the recording sheet is conveyed. 
     In this constitution, since the pattern for measurement is formed in a plurality of stripe patterns having different directions, inclination of the recording head can be easily measured from an intensity of a Moire fringe generated by recording the image for measurement. The present constitution corresponds to the second embodiment described later. 
     Additionally, a recording sheet according to a seventh aspect of the present invention relates to the recording sheet according to the first aspect of the present invention, and a region of the pattern for measurement is subjected to blur preventive processing of ink with respect to at least a conveying direction of the recording sheet. 
     In this constitution, since the region of the pattern for measurement is subjected to the blur preventive processing of the ink, the positional relationship between the pattern for measurement and the image for measurement can be more correctly measured. The present constitution corresponds to the first embodiment described later. 
     Moreover, a recording sheet according to an eighth aspect of the present invention relates to the recording sheet according to the first aspect of the present invention, and an identification mark indicating a type of the pattern for measurement is disposed on a sheet surface of the recording sheet. 
     In this constitution, since the identification mark indicating the type of the pattern for measurement is attached, identification of the pattern for measurement or distinction from a usual recording sheet can be automatically performed. The present constitution corresponds to the second embodiment described later. 
     Furthermore, a recording sheet according to a ninth aspect of the present invention relates to the recording sheet according to the ninth aspect of the present invention, and the recording sheet is a rolled sheet having the pattern for measurement in a tip portion. 
     In this constitution, since the rolled sheet having the pattern for measurement in the tip portion is used, it is possible to correct the positional shift of the recorded dot of the image whose recording width is expanded by interconnection of the images recorded by a plurality of recording heads. The present constitution corresponds to the third embodiment described later. 
     Additionally, according to a tenth aspect of the present invention, there is provided an image recording apparatus in which the recording sheet according to any one of the first to sixth aspects of the present invention is used and which records an image whose recording width is expanded by interconnection of the images recorded on the sheet for recording by a recording head, the apparatus comprising: a measurement image generation section which produces an image for measurement to make possible positional shift measurement of a recorded dot recorded on the pattern for measurement by the recording head; a positional shift measurement section which measures a positional shift amount based on a positional relationship between the image produced by the measurement image generation section and the pattern for measurement; and a position correction section which corrects a position of a recorded image formed by the recording head based on the positional shift amount measured/obtained by the positional shift measurement section. 
     In this constitution, the image for measurement combined with the pattern for measurement so that the positional shift of the recording head can be measured is produced and recorded, and therefore the positional shift of the recorded dot of the image recorded by the recording head can be corrected. The present constitution corresponds to the first embodiment described later. 
     Moreover, an image recording apparatus according to an eleventh aspect of the present invention relates to the image recording apparatus according to the tenth aspect of the present invention, and comprises: a mark identification section which identifies presence/absence of an identification mark and type of the recording sheet according to the eighth aspect of the present invention; and an image data selection device which selects image data for measurement to be recorded in accordance with an identification result in the mark identification section. 
     Since this constitution comprises the mark identification section which identifies the type of the recording sheet, and the image data selection device which selects the image data to be recorded in accordance with the identification result in the mark identification section, the type of the recording sheet to be supplied is identified, and a user records an input image with a usual recording sheet. When the recording sheet has the pattern for measurement, the image for measurement can be automatically selected and recorded in accordance with the pattern for measurement. The present constitution corresponds to the first embodiment described later. 
     Furthermore, an image recording apparatus according to a twelfth aspect of the present invention relates to the image recording apparatus according to the tenth aspect of the present invention, comprises a detection section which detects that the recording sheet has been replaced, and records the image for measurement is recorded at a first image recording time after detecting the replacement of the recording sheet in the detection section. 
     Since this constitution comprises the detection section to detect the replacement of the recording sheet, and records the image for measurement at the first image recording time after detecting the replacement of the recording sheet to correct the positional shift of the recorded dot every time a roll of recording sheet is replaced, a high image quality can be constantly maintained. The present constitution corresponds to the first embodiment described later. 
     Additionally, an image recording apparatus according to a thirteenth aspect of the present invention relates to the image recording apparatus according to the tenth aspect of the present invention, and the positional shift measurement section includes an image reading section using a line sensor which scans in a direction intersecting with a line constituting at least an image or a pattern of the image for measurement and the pattern for measurement in an oblique direction to read the image. 
     In this constitution, since the image reading section scans in the oblique direction with respect to a sheet conveying direction at an image recording time to read the image, a correction amount of a recorded dot position can be calculated with high precision. 
     Moreover, an image recording apparatus according to a fourteenth aspect of the present invention relates to the image recording apparatus according to the tenth aspect of the present invention, and includes: an image rotation section which rotates image data read by the image reading section; an interpolation section which interpolates each row of the image data rotated by the image rotation section to increase the number of data; and an average value calculation section which calculates an average value of each column of output data of the interpolation section. 
     In this constitution, the image scanned and read in the oblique direction with respect to a sub-scanning direction at the image recording time is rotated so as to dispose a stripe pattern or the like which is a content of the image in parallel with an outer frame of the image in the image rotation section, the number of data is increased in the interpolation section, and subsequently the average value is obtained in the average value calculation section, so that the correction amount of the recorded dot position can be calculated with high precision. The present constitution corresponds to the third embodiment described later. 
     Furthermore, an image recording apparatus according to a fifteenth aspect of the present invention relates to the image recording apparatus according to the tenth aspect of the present invention, the pattern for measurement comprises parallel lines arranged at equal intervals, the image for measurement also comprises parallel lines arranged at equal intervals, and the positional shift measurement section measures a positional shift amount of the recorded dot recorded by the recording head in accordance with a Moire pattern produced by the pattern for measurement and the image for measurement. 
     In this constitution, in the Moire fringe measurement section, Moire fringes are checked which are generated in the image obtained by recording the image for measurement in the pattern for measurement comprising a plurality of stripe patterns having different directions in the recording sheet according to the sixth aspect of the present invention, and an inclination of the recording head is obtained from a direction of the stripe pattern having a longest period of Moire fringe. The present constitution corresponds to the second embodiment described later. 
     Moreover, according to a sixteenth aspect of the present invention, there is provided an image recording apparatus comprising: a first recording section which records a first image capable of distinguishing a line direction of a recording head; a second recording section which records a second image capable of distinguishing a conveying direction of a recording sheet; and a recorded dot position correction section which corrects a position of a recorded dot formed by the recording head in accordance with an angle formed by the line direction obtained from the first image and the conveying direction obtained from the second image. 
     In this constitution, in order to direct the recording head vertically to the conveying direction of the recording sheet, an attaching angle of the recording head is obtained in the recording section which records the first image capable of distinguishing the conveying direction of the recording sheet, and the recording section which records the second image capable of distinguishing the line direction of a recording device disposed in the recording head. Therefore, the position of the recorded dot can be corrected using angle information in the recorded dot position correction section. The present constitution corresponds to the fourth embodiment described later. 
     Moreover, an image recording apparatus according to a seventeenth aspect of the present invention relates to the image recording apparatus according to the sixteenth aspect of the present invention, and further includes an image reading section which reads the first and second images recorded on a sheet for recording, and the recorded dot position correction section includes an angle calculation section which obtains an angle formed by the line direction and the conveying direction from the image data read by the image reading section. 
     Since this constitution includes the image reading section and angle calculation section in addition to the constitution of the image recording apparatus according to the sixteenth aspect of the present invention, a correction process of the recorded dot position can be performed only by the present apparatus. The present constitution corresponds to the fourth embodiment described later. 
     Furthermore, according to an eighteenth aspect of the present invention, there is provided an image recording apparatus comprising: a plurality of recording heads which expand a recording width by interconnection of recorded images to record the images; and a measurement pattern generation section to produce image data for measurement including a pattern in which positions of line directions of the plurality of recording heads are fixed and a pattern in which the positions of the line directions are moved every line or lines. 
     In this constitution, the image obtained by inputting and recording the image data produced in the measurement pattern generation section in each of the plurality of recording heads includes the pattern in which the position of the line direction is fixed and the pattern in which the position moves in the line direction. Therefore, the positional relationship of the plurality of recording heads in the line direction can be easily checked by the positional relationship between the pattern in which the position of the line direction recorded by one of two adjacent recording heads is fixed and the pattern which moves in the line direction recorded by the other recording head. The present constitution corresponds to the sixth embodiment described later. 
     Moreover, an image recording apparatus according to a nineteenth aspect of the present invention relates to the image recording apparatus according to the eighteenth aspect of the present invention, and the image data for measurement is a figure comprising a segment in which a position of one end in the line direction is fixed and a position of the other end changes every line or lines. 
     In this constitution, the image data produced in the measurement image generation section forms an image whose width of the line direction changes. Therefore, a position of a gap (non-printed portion) generated in the image formed by inputting and recording the image data in each of the plurality of recording heads can be checked to easily check the positional relationship among the plurality of recording heads in the line direction. The present constitution corresponds to the sixth embodiment described later. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         FIG. 1A  is a diagram showing a first embodiment of the present invention, and  FIG. 1B  is a diagram showing a relationship between a recording head and a recorded dot; 
         FIG. 2  is an enlarged view of a part of an image in a state in which an image for measurement  104  is formed on a pattern for measurement; 
         FIGS. 3A and 3B  are explanatory views of a recording sheet capable of preventing ink from blurring; 
         FIG. 4  is a diagram showing a second embodiment of the present invention; 
         FIG. 5  is a diagram showing a third embodiment of the present invention; 
         FIG. 6  is an explanatory view of a pattern reading operation; 
         FIG. 7  is a diagram showing image data read by a scanning operation of a line sensor  503 ; 
         FIG. 8  is an explanatory view of details of a recorded dot position calculation section; 
         FIG. 9  is a diagram showing image data produced by rotation conversion of the image data read in a pattern reading section  901 ; 
         FIG. 10  is a diagram in which the image data shown in  FIG. 9  is interpolated/enlarged in a transverse direction by an interpolation enlargement section  904 ; 
         FIG. 11  is a diagram showing a one-dimensional data string obtained by calculating an average value in an average value calculation section  904 ; 
         FIG. 12  is an explanatory view of measurement of a shift amount of a recorded dot; 
         FIG. 13  is a diagram showing an image recorded on a recording sheet by image data produced by a measurement pattern generation section  407 , and a positional relationship between recording heads  1206  and  1207 ; 
         FIG. 14  is an explanatory view of a principle in which a recorded dot position calculation section  409  reads a coordinate of a mark from a read image to calculate the shift amount of the recorded dot position; 
         FIGS. 15A and 15B  are explanatory views of another method in which an angle of a line direction with respect to a conveying direction is obtained; 
         FIG. 16  is a diagram showing a constitution of an image recording apparatus of a fifth embodiment of the present invention; 
         FIG. 17  is an explanatory view of an image for measurement produced by a measurement pattern generation section  1507 ; 
         FIG. 18  is an explanatory view of a method in which a dividing position of the image data is determined in a sixth embodiment of the present invention; and 
         FIG. 19  is a diagram showing a shape of the image data to be input into recording heads  1801   a  to  1801   d.    
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of the present invention will be described hereinafter in detail with reference to the drawings. 
     (First Embodiment) 
       FIG. 1A  is a diagram showing a first embodiment of the present invention. In  FIG. 1A , reference numeral  101  denotes a recording sheet main body,  102  denotes a pattern for measurement, and  105  denotes marks indicating a type of the pattern for measurement  102 . An interval between lines of the pattern for measurement  102  is twice a basic dot pitch in a sheet conveying direction of an image recording apparatus.  FIG. 1B  is a diagram showing a relationship between a recording head and a recorded dot. In  FIG. 1B ,  101 ,  102 , and  105  are common to those of  FIG. 1A . 
     Reference numerals  103   a  to  103   d  of  FIG. 1B  denote recording heads, and a positional relationship of them is shown. The recording heads  103   a  to  103   d  are arranged in such a manner that portions of recording ranges overlap with each other, and an image can be recorded in a width substantially equal to a transverse width of the recording sheet  101 . The width of the pattern for measurement  102  is preferably equal to or larger than a recording width by the recording heads  103   a  to  103   d . Reference number  104  denotes an image for measurement recorded by driving an optional number of recording devices of end portions of the recording heads  103   a  to  103   d . The recording sheet  101  is relatively moved with respect to the recording heads  103   a  to  103   d  in a direction of an arrow  106  of the drawing to record the image. 
     The recording heads  103   a  to  103   d  are not linearly arranged, but a recording timing is controlled, and accordingly recorded dots can be formed substantially on the same straight line. The image for measurement  104  is recorded by repetition of printing/non-printing for each line, and an interval of the image in the conveying direction of the recording sheet  101  is twice a minimum dot interval in the same manner as in the pattern for measurement  102 . 
     A line width of the pattern for measurement  102  is smaller than that of the image for measurement  104 , and both can be easily distinguished. Alternatively, the pattern for measurement  102  may also be formed in a color different from that of the image for measurement  104  to facilitate the distinction. For example, when the color of the image for measurement  104  is cyan, the color of the pattern for measurement  102  is set to magenta, and accordingly the distinction between both is easily performed. For example, when the image for measurement  104  has four colors of black, cyan, magenta, and yellow, for example, two cyan and magenta patterns for measurement are used, and accordingly it is possible to measure the image for measurement of any color. 
       FIG. 2  is an enlarged view of a part of an image in a state in which the image for measurement  104  is formed on a pattern for measurement. In  FIG. 2 ,  201  denotes the pattern for measurement, and corresponds to  102  of  FIGS. 1A ,  1 B.  205   a ,  205   b ,  206   a ,  206   b  are images for measurement, and correspond to  104  of  FIG. 1B .  202 ,  204   a ,  204   b  are recording heads, their positional relationship is shown in  FIG. 2 , and they correspond to  103   a ,  103   b ,  103   c  of  FIG. 1B. 203  denotes a recording device formed on the recording head  202 . In the image recording apparatus of an ink jet system, the recording device comprises nozzles which discharge ink. 
     In  FIG. 2 , since the images for measurement  205   a ,  205   b  formed in opposite end portions of the recording head  202  have different positions with respect to the pattern for measurement  201 , it is seen that the recording head  202  is inclined on the basis of the pattern for measurement  201 . Since the pattern for measurement  201  and images for measurement  205   a ,  205   b  both have repeated patterns, a shift amount from the pattern for measurement  201  is individually obtained with respect to each line of the images for measurement  205   a ,  205   b  or the like, an average value is obtained, and accordingly a positional shift of a recorded dot can be measured more correctly. 
     When the shift amount between the pattern for measurement and the image for measurement is similarly obtained also with respect to another recording head, and an attaching position or a recording timing of each head is adjusted to obtain a shift amount of  0 , the position of the recorded dot recorded by each recording head moves onto a straight line, and an image can be formed without any distortion. 
     It is to be noted that a range in which the pattern for measurement exists on the recording sheet is subjected to processing so as to reduce the blur of the ink, and accordingly the position of the image for measurement can be measured more correctly.  FIGS. 3A ,  3 B are explanatory views of the recording sheet subjected to this processing. In  FIG. 3A ,  1301  denotes a recording sheet, and  1302  denotes a pattern for measurement. A range  1303  including at least a part of the pattern for measurement  1302  is subjected to the blur preventive processing of the ink. For example, with the use of aqueous ink, the surface of the recording sheet is processed so as to be slightly lipophilic. 
     The recording sheet  1301  a part of whose surface has been subjected to the blur preventive processing of the ink is also effective for measuring density unevenness to correct the density unevenness of the image recording apparatus. In  FIG. 3B ,  1304  and  1305 - 1 ,  1305 - 2 ,  1305 - 3  denote images recorded by the recording head. The other numerals denote the same components as those of  FIG. 3A . It is assumed here that  1305 - 1  has a high density,  1305 - 3  has a low density, and  1305 - 2  has an intermediate density. 
     Since the density unevenness generally appears differently depending on the density of the recorded image, as shown by  1305 - 1  to  1305 - 3 , a uniform image signal is input in various densities, the recording head is driven to form the image, and the generated density unevenness is measured to calculate a density unevenness correction amount. At this time, it is important to correctly associate the position of the density unevenness with that of the recording element and to grasp a distribution shape of the density unevenness. Here, when a part of the image for the measurement of the density unevenness is recorded in a range shown by  1303 , subjected to the blur preventive processing of the ink, a central position of each recorded dot forming the image can be easily specified in the range, and accordingly the distribution of the density unevenness can be correctly associated with the position of the recording element. 
     (Second Embodiment) 
       FIG. 4  is a diagram showing a second embodiment of the present invention. In  FIG. 4 ,  301  denotes a recording sheet main body,  302   a  to  302   e  denote patterns for measurement, and  303  denotes an image for measurement. The patterns for measurement  302   a  to  302   e  are formed beforehand on the recording sheet  301  of the present embodiment, and the image for measurement  303  is recorded by the recording head, when a correction amount of a recorded dot position is obtained. The patterns for measurement  302   a  to  302   e  have slightly different inclinations, and inclination angles are known. An interval of the patterns for measurement  302   a  to  302   e  and image for measurement  303  in the conveying direction of the recorded dot is twice the minimum dot interval in the same manner as in Embodiment 1 of the recording sheet. Reference numeral  304  denotes an identification mark for identifying a sheet type. 
     When the recording head is inclined and disposed with respect to the conveying direction of the recording sheet, the image for measurement  303  is also inclined and recorded. When the image for measurement  303  is recorded on the patterns for measurement  302   a  to  302   e , Moire fringes are generated because of a difference of the angle of the pattern. In the Moire fringes, the number of fringes decreases in a case where a difference of the angle between both the patterns is small. Conversely, when the difference of the angle between both the patterns is large, the number of fringes increases. Therefore, the inclination angle of the recording head can be known from that of the pattern for measurement in which the number of Moire fringes is smallest. 
     In the example of  FIG. 4 , since the number of Moire fringes is minimum on the pattern for measurement  302   a , it is seen that the inclination angle of the recording head is substantially equal to that of the pattern for measurement  302   a . The pattern for measurement  302   a  whose inclination is more finely changed is prepared beforehand, and accordingly the inclination angle of the recording head can also be read more correctly. 
     (Third Embodiment) 
       FIG. 5  is a diagram showing a third embodiment of the present invention. In  FIG. 5 :  401  denotes an image memory which holds an input image;  402  denotes an image dividing section which divides the input image by a plurality of recording heads to record the images;  403  denotes an image data selection device which selects image data to be recorded from the input image and an image for measurement;  404  denotes an image memory which holds the divided image data;  405  denotes a recording head driver which drives/controls the recording head;  406  denotes a recording head;  407  denotes a ROM (generation section of the pattern for measurement) in which the data of the pattern for measurement is stored;  408  denotes an image scanner which is a pattern reading section;  409  denotes a recorded dot position calculation section;  410  denotes an image data correction section;  411  denotes a printing timing correction amount calculation section; and  412  denotes a recording sheet judging section which distinguishes the recording sheet. Elements in a broken-line frame  413  exist in each of a plurality of recording heads. 
     Next, an operation will be described. When the recording sheet having the pattern for measurement shown in  FIG. 1  or  4  is set on the image recording apparatus of the present embodiment, the recording sheet judging section  412  reads the identification mark shown by  105  of  FIG. 1  or  304  of  FIG. 4  to recognize that the recording sheet having the pattern for measurement has been set. Moreover, the recording sheet judging section  412  instructs the image data selection device  403  to select an input from the measurement pattern generation section  407  and to write the image data of the pattern for measurement into the image memory  404 . 
     In this case, the image data correction section  410  and the printing timing correction amount calculation section  411  are not allowed to operate, and the image data stored in the image memory  404  is not subjected to correction of the recorded dot position, and is recorded by the recording head  406  via the recording head driver  405 . The recorded image (not shown) is read by the pattern reading section  408 , and the position of the dot recorded by each recording head is analyzed in the recorded dot position calculation section  409 . The recorded dot position is corrected by decomposition into rotational movement and parallel movement. 
     A rotational movement amount to correct the inclination of the recorded dot and a parallel movement amount to correct the positional shift of the recording head in a direction crossing the conveying direction of the recording sheet at right angles are transmitted to the image data correction section  410 . On the other hand, the parallel movement amount to correct the positional shift of the recorded dot in the conveying direction of the recording sheet is transmitted to the printing timing correction amount calculation section  411 , and accordingly the operation timing of the recording head driver  405  is controlled. 
     When a usual recording sheet is set on the present image recording apparatus, the recording sheet judging section  412  identifies the usual recording sheet, and instructs the image data selection device  403  to select a usual image. Accordingly, the image data selection device  403  selects input image data obtained by dividing the image data held in the image memory  401  and divided for each of the plurality of recording heads in the image dividing section  402 , and writes the data into the image memory  404 . 
     The image data stored in the image memory  404  is subjected to deformation processes such as the rotation and parallel movement in the image data correction section  410  by an amount corresponding to the parallel movement amount to correct the inclination angle of the recording head for use in recording the image data and the positional shift of the recording head in the direction crossing the conveying direction of the recording sheet at right angles, and the data is converted to minimize the distortion of the recorded image. The converted image data is read by the recording head driver  405 , and recorded on the recording sheet by the recording head  406  at a timing at which the image is correctly reconstituted by a plurality of recording heads in accordance with the printing timing calculated in the printing timing correction amount calculation section  411 . 
     In the pattern reading section  408 , a linear image sensor scans the image to read the image. In this case, the image sensor scans and reads the image in the oblique direction with respect to the pattern for measurement or the stripe pattern of the image for measurement. The angle may be an angle at which a reading element of the image sensor obliquely crosses and reads several stripe patterns during the scanning of the linear image sensor of the pattern reading section  408 . Because sampling points for reading the image with respect to the stripe pattern in the image sensor increase at this angle, and it is therefore possible to read an edge portion of the stripe pattern more correctly. 
       FIG. 6  is an explanatory view of the reading operation. In  FIG. 6 ,  501  denotes a recording sheet,  502  denotes a pattern for measurement owned by the recording sheet  501  or an image for measurement formed on the recording sheet,  503  denotes a line sensor which is the pattern reading section ( 408  of  FIG. 5 ), and  504  schematically shows a reading element (light receiving element) of the line sensor  503 . When the line sensor  503  is scanned in a direction of an arrow  505  to read the image, the image data shown in  FIG. 7  is obtained. Here, for the convenience of description, the operation will be described using a stripe pattern, but, in actuality, the stripe pattern in which the pattern for measurement has overlapped with the image for measurement is read, and the pattern is separated from the image using a difference of color or position so that the positional relationship between the pattern and the image is known. 
     Here, details of the recorded dot position calculation section ( 409  of  FIG. 5 ) will be described with reference to  FIG. 8 . Reference numeral  901  denotes the pattern reading section, and corresponds to  408  of  FIG. 5 . Reference numerals  902  to  905  correspond to the recorded dot position calculation section  409  of  FIG. 5 . Reference numeral  902  denotes an image data rotation conversion section,  903  denotes an image data interpolation enlargement section,  904  denotes an average value calculation section which obtains an average value of the image data for each string, and  905  denotes a peak interval calculation section. A printing timing correction amount calculation section  906  corresponds to  411  of  FIG. 5 , and an image data correction section  907  corresponds to  410  of  FIG. 5 . 
     In the image data rotation conversion section  902  to the average value calculation section  904  which obtains the average value for each string of the image data, a density distribution shape of the stripe pattern is obtained while obtaining the positional relationship between the pattern for measurement and the image for measurement. The image data is rotated/converted by the image data rotation section  902  in such a manner that the direction of the stripe of the stripe pattern of the image data shown in  FIG. 7  read by the pattern reading section  901  becomes vertical, and the image data shown in  FIG. 9  is produced. Additionally, a blank portion is removed in  FIG. 9 . Furthermore, the image data interpolation enlargement section  903  interpolates/enlarges the data in a transverse direction to obtain the image data as shown in  FIG. 10 . A method of interpolation/enlargement may be a simple method such as primary interpolation (straight line interpolation), or a more sophisticated method may also be used. A magnification of enlargement changes by a degree of precision with which the position of the recorded dot is to be corrected. However, for example, to perform the correction with a precision which is about 1/10 of a basic dot pitch, the magnification of enlargement may be set to about ten times. When the magnification of enlargement is set to ten times, a pitch of  FIG. 10  is about 20 pixels. 
     Next, the average value calculation section  904  which obtains the average value for each string of image data calculates the average value of densities of pixels constituting the image data of  FIG. 10  for each string in a vertical direction and, as a result, a one-dimensional data string is obtained as shown in  FIG. 11 . A peak interval is about 20 pixels. The peak interval calculation section  905  compares the position of the one-dimensional data string obtained as described above in the opposite ends of each of the plurality of recording heads to calculate the shift amount of the recorded dot position, further calculates a parallel movement component and a rotational movement component for correcting the positional shift, and outputs the components to the printing timing correction amount calculation section  906  and image data correction section  907 . 
     A reason why detailed information of the density distribution of the stripes is obtained by the above-described process will be described in accordance with an example. The stripe pattern shown by  502  of  FIG. 6  is recorded with a resolution of 300 dpi, and a reading resolution of the image scanner  503  is 1200 dpi, and when the pattern is simply read in parallel with a stripe direction, only eight data are obtained in a period of the stripes, and eventually the position of the peak of the density of the stripes is only read with a resolution of 1200 dpi which is the resolution of the scanner. Even with the interpolation/enlargement in a direction vertical to the stripes, there is not any change in the position of the peak of the densities of the stripes. 
     However, when the stripe pattern on the recording sheet is obliquely scanned with respect to the direction of the stripes as described here, an effect of the reading at a resolution exceeding that of the scanner is produced. Therefore, when the read image data is interpolated/enlarged in the direction vertical to the stripes, detailed information of the density distribution is obtained rather than in the interpolation/enlargement of the image scanned at 1200 dpi. 
     Since the peak position of the density of the stripes can be obtained correctly in this manner, the peak position of the pattern for measurement is compared with that of the image for measurement, and accordingly the shift amount of the recorded dot can be measured. 
       FIG. 12  is an explanatory view of measurement of the shift amount of the recorded dot. In  FIG. 12 ,  1401  denotes a part of the pattern for measurement, and  1402  denotes a part of the image for measurement. It is assumed that both positions shift by a ¼ pixel pitch. Each density distribution shape is obtained by the above-described process. Reference numeral  1403  denotes a density distribution shape of the pattern for measurement  1401 , and  1404  denotes a density distribution shape of the image for measurement  1402 . Abscissa  1405  of a graph indicates the position, and ordinate  1406  indicates the density. The shift amount between both the positions is known by a difference  1407  of the peak position between the density distribution shapes  1403  and  1404 . 
     (Fourth Embodiment) 
     In the present embodiment, when a plurality of recording heads are joined to expand a recording width, and the image is recorded, in order to record the image without any distortion, the line direction of the recording element of each recording head is set to be correctly vertical to the conveying direction of the recording sheet. Moreover, the correction amount of the recorded dot position is obtained in order that the recorded dots of the adjacent recording heads are correctly laid on the same straight line. 
     The constitution of the image recording apparatus of the present embodiment is substantially similar to that of the third embodiment, and can be shown in  FIG. 5 . Additionally, the usual recording sheet which does not have any pattern for measurement is used as the recording sheet. That is, the recording sheet judging section ( 412  of  FIG. 5 ) is not required. Since the pattern produced by the measurement pattern generation section ( 407  of  FIG. 5 ), the pattern reading section ( 408  of  FIG. 5 ), and the process content of the recorded dot position calculation section  409  differ, they will be described. 
     First, a user operates the image data selection device  403 , and drives the recording head  406  to record the image data produced by the measurement pattern generation section  407 . Images shown by  1201  to  1205  of  FIG. 13  are recorded on the recording sheet by the image data produced by the measurement pattern generation section  407 . In  FIG. 13 ,  1209  denotes a recording sheet, and  1206  and  1207  show a positional relationship between the recording heads. 
     The reference numerals  1201  and  1203  are images for distinguishing the conveying direction of the recording sheet, and correspond to the second image of the “sixteenth aspect” of the present invention described in the Brief Summary of the Invention. Here, they are referred to as conveying direction marks. The recording sheet  1209  is conveyed in a direction of  1208 , and certain recording elements in the end portions of the recording heads  1206  and  1207  are repeatedly driven to record the marks. Lengths may be optional, but a certain length is required for correctly measuring the inclinations of the recording heads  1206  and  1207 . The lengths equal to the recording widths of the recording heads  1206  and  1207  may be standards. 
     Reference numerals  1202  and  1204  are images for identifying the line direction of the recording element disposed in the recording head, and correspond to the first image of the “sixteenth aspect” of the present invention described in the Brief Summary of the Invention. Here, they are referred to as line direction marks. All the recording elements of the recording heads  1206  and  1207  are simultaneously driven to record the marks. 
     Furthermore, the marks capable of distinguishing the pitch of the recorded dots shown by  1205  are recorded in order to facilitate the measurement of the positional relationship between the adjacent recording heads. The recording head  1207  is driven to record the mark. Accordingly, the positional relationship between the line direction mark  1202  recorded by the recording head  1206  and the mark  1205  recorded by the recording head  1207  becomes obvious. 
     Next, the above-described image is read in the pattern reading section  408 . In the third embodiment, the scanning direction of the image reading sensor is set to a direction different from the conveying direction of the recording sheet, but this is not especially required in this embodiment. 
     Next, the recorded dot position calculation section  409  reads the coordinate of the mark from the read image to calculate the shift amount of the recorded dot position. 
     This principle will be described with reference to  FIG. 14 . In  FIG. 14 ,  1101  denotes a conveying direction mark, and corresponds to  1201  and  1203  of  FIG. 13 . Reference numeral  1102  denotes a line direction mark, and correspond to  1202  and  1204  of  FIG. 13 . A coordinate of three points O, A, B shown in  FIG. 14  is read from the conveying direction mark  1101  and line direction mark  1102 . An address of the image data in X, Y-directions of the image data is used in the coordinate. 
     Assuming that the coordinates of three points O, A, B are (xo, yo), (xa, ya), (xb, yb) and an angle  1105  formed by the conveying direction mark  1101  and line direction mark  1102  is θ, θ can be obtained by the following equation (1): 
     
       
         
           
             
               
                 
                   
                     
                       
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     In this case, a unit is radian. On the basis of 90 degrees (0.5π radians), when θ shifts from 90 degrees, the shift amount is a recorded dot position correction amount. For example, θ is 91 degrees, the attaching angle of the recording head in which the line direction mark  1102  is recorded is rotated clockwise by one degree, and accordingly the position of the recorded dot matches a standard position. 
     Moreover, the positional shift amount of the recorded dot is read between the adjacent recording heads using the mark capable of distinguishing the pitch of the recorded dot shown by  1205  of  FIG. 13 . The correction amount of the recorded dot position of each recording head is calculated based on information on the positional shift of the recorded dot. For example, when the angle formed by the conveying direction mark  1201  and line direction mark  1202  is represented by the shift amount of the line direction mark  1202  in lower and upper ends in  FIG. 13 , the upper end shifts to the left by one dot as compared with the lower end, and the lower end of the line direction mark  1204  shifts to the right by 1.5 dots with respect to the upper end of the line direction mark  1202 . When this is measured, the recording head  1206  is rotated/moved in such a manner that the upper end moves to the right by one dot, and the recording head  1207  may be moved in parallel in a left direction by 0.5 dots obtained by subtracting one dot of rotation correction of the recording head  1206 . 
     Moreover, even when the angle formed by the conveying direction mark  1203  and line direction mark  1204  is not 90 degrees, the position of the upper end of the recording head  1207  may be similarly adjusted to correct the angle as 90 degrees. 
     In the present embodiment, the mark shown by  1205  is used to facilitate the measurement of the positional relationship between the adjacent recording heads. However, when the coordinates of end points of the line direction marks  1202  and  1204  are correctly known using the image scanner or the like, the mark shown by  1205  is not necessarily required. 
     A method of obtaining the angle of the line direction with respect to the conveying direction is not limited to the above-described method, and various methods are applicable. For example, as shown in  FIG. 15A , only a part of the conveying direction mark may also be recorded as in  1006 ( a ),  1006 ( b ), and only a part of the line direction mark may also be recorded as in  1007 ( a ),  1007 ( b ). As shown in  FIG. 15B , when a recorded dot  1008  capable of identifying the recorded dot interval is added to the line direction mark, the shift amount from the standard position of the recorded dot may also be directly obtained in an amount by a unit of the recorded dot interval. 
     As described above, since the correction amount of the position of the recorded dot is obtained, the position of the recorded dot may be similarly corrected in the same manner as in the third embodiment. 
     (Fifth Embodiment) 
       FIG. 16  is a diagram showing a constitution of the image recording apparatus of the present embodiment. In  FIG. 16 :  1501  denotes an image memory which holds an input image;  1502  denotes an image dividing section which divides the input image by a plurality of recording heads to record the images;  1503  denotes an image data selection device which selects image data to be recorded from the input image and an image for measurement;  1504  denotes an image memory which holds the divided image data;  1505  denotes a recording head driver which drives/controls the recording head;  1506  denotes a recording head;  1507  denotes a ROM (generation section of the pattern for measurement) in which the data of the pattern for measurement is stored;  1508  denotes an image scanner which is a pattern reading section;  1509  denotes an image data rotation conversion section;  1510  denotes an image data interpolation enlargement section;  1511  denotes an average value calculation section which obtains an average value for each string of the image data;  1512  denotes a peak interval calculation section which calculates a peak interval of a density distribution shape; and  1513  denotes a recording head position correction section. Elements in a broken-line frame  1514  exist in each of a plurality of recording heads. 
     Next, an operation of the image recording apparatus of the present embodiment will be described. When usual image recording is performed, the user operates the image data selection device  1503  to select the data obtained by dividing the image data held by the image memory  1501  for each of the plurality of recording heads by the image dividing section  1502  to store the data in the image memory  1504 . The image data stored in the image memory  1504  is read by the recording head driver  1505 , reconstituted into an image on the recording sheet (not shown) by a plurality of recording heads  1506 , and recorded. 
     To adjust the interval between the adjacent recording heads, the user operates the image data selection device  1503 , and selects the image data produced by the measurement pattern generation section  1507  to store the data in the image memory  1504 . The image data stored in the image memory  1504  is read by the recording head driver  1505 , reconstituted into an image on the recording sheet (not shown) by a plurality of recording heads  1506 , and recorded. 
     The image for measurement produced by the measurement pattern generation section  1507  will be described with reference to  FIG. 17 . In  FIG. 17 ,  1601  and  1602  show two adjacent recording heads, but a part is omitted from the drawing. Reference numeral  1603  denotes recording elements linearly arranged and formed on the recording head. The recording elements shown by black circles indicate recording elements which form the recorded dots in recording the image for measurement produced by the measurement pattern generation section  1507 , and the recording elements shown by white circles indicate recording elements which do not form the recorded dots. Reference numeral  1604  shows a part of the recording sheet. 
     To perform the recording, a recording sheet  1604  is conveyed in a direction of an arrow  1611 . Reference numeral  1605  denotes an image produced by the measurement pattern generation section  1507  and recorded on the recording sheet  1604 . The image for measurement produced by the measurement pattern generation section  1507  is a stripe pattern parallel to the conveying direction of the recording sheet, obtained by driving the recording elements every other dot. 
     Here, a method of correcting an interval between the adjacent recording heads will be described with reference to  FIG. 16 . A constitution shown by  1508  to  1512  is similar to that shown by  901  to  905  of  FIG. 8  described in the third embodiment. The image for measurement recorded on the recording sheet is read by the pattern reading section  1508 , and converted into image data. At this time, the image is scanned and read in a direction different from the conveying direction of the recording sheet as shown in  FIG. 6  to obtain the image data of the stripe pattern inclined as shown in  FIG. 7 . 
     The image data of the stripe pattern shown in  FIG. 7  rotated/converted by the image data rotation conversion section  1509  in such a manner that the stripes extend in a vertical direction, and the image data is produced as shown in  FIG. 9 . Furthermore, the image data interpolation enlargement section  1510  interpolates/enlarges the data in a direction shown by an arrow  701  of  FIG. 9  to obtain image data as shown in  FIG. 10 . A method or a magnification of interpolation/enlargement is set in the same manner as in the third embodiment. 
     Next, the average value calculation section  1511  which obtains the average value for each string of the image data calculates the average of density values of pixels constituting the image data of  FIG. 10  for each string in a direction shown by an arrow  801  of  FIG. 10 , and a one-dimensional data string indicating the density distribution shape is obtained. A curve  1606  of  FIG. 17  shows the density distribution shape for the image for measurement  1605  recorded on the recording sheet. In a graph of  FIG. 17 , the abscissa  1607  indicates the direction crossing the conveying direction of the recording sheet at right angles, and the ordinate  1608  indicates the density. 
     On receiving the data string of the density distribution shape produced by the average value calculation section  1511  which obtains the average value for each string of the image data of  FIG. 16 , the peak interval calculation section  1512  calculates a recording element interval (interval between two recording elements) shown by  1609  of  FIG. 17  and a recording head interval shown by  1610 . When two intervals shown by  1609  and  1610  indicate an equal value, the interval between two recording heads is appropriate for recording the image without any distortion. 
     When there is a difference in two intervals shown by  1609  and  1610  in  FIG. 17 , the recording head interval needs to be corrected in order to record the image without any distortion, and the difference between two intervals shown by  1609  and  1610  is a correction amount. The correction amount is transmitted to the recording head position correction section  1513  of  FIG. 16 , and the recording head position correction section  1513  corrects the position of the recording head  1506 . Various methods are applicable to a method of moving the position of the recording head, but in this embodiment, a piezoelectric element shown by  1613  of  FIG. 17  is used. The piezoelectric element is capable of changing a voltage to be applied to the element to control the thickness. 
     In  FIG. 17 , when the recording head  1601  is attached to a fixed member  1612  such as a housing of the image recording apparatus via the piezoelectric element  1613 , the voltage to be applied to the piezoelectric element  1613  is controlled, so that the position of the recording head  1601  can be moved/controlled in a direction crossing the conveying direction of the recording sheet at right angles. When the interval between the adjacent recording heads  1601  and  1602  is adjusted in this manner, the position of the recorded dot can be corrected to record the image without any distortion. It is to be noted that even when the usual image recording is continuously performed, the above-described position correction of the recorded dot is sometimes performed in the intervals between the usual image recording, the recorded dot position can be constantly appropriately kept. 
     The average value is used for obtaining the density distribution shape in the above description, but another statistical value such as a total value may also be used. 
     (Sixth Embodiment) 
     In the present embodiment, a method of determining a dividing position of the image data will be described with reference to  FIG. 18  in a case where the image data is divided into the line direction of the recording head, and input into a plurality of recording heads, and the image is reconstituted and recorded by the plurality of recording heads. 
     In  FIG. 18 ,  1800  denotes a recording sheet, and  1801   a  to  1801   d  denote recording heads. The recording heads  1801   a  to  1801   d  are arranged in such a manner that portions of recordable ranges overlap with each other. 
     A recorded image  1802  indicates an image recorded by inputting the image data having a shape shown in  FIG. 19  into the recording heads  1801   a  to  1801   d . In the image data shown in  FIG. 19 ,  1900  denotes printing data, and  1901  denotes non-printed data. A width of the printing data is constituted to decrease by each pixel for each constant number m of lines. That is, assuming that a total printing width of the recording head is N pixels, the first m line width corresponds to the N pixels, the next m line width corresponds to (N−1) pixels, further the next m line width corresponds to (N−2) pixels, and subsequently the width similarly decreases by one pixel every m lines. This is repeated until reaching a width obtained by subtracting a supposed maximum head overlap width from a head width. 
     The line constituting the recorded image  1802  is first a connected line (in an upper part of the drawing). When the recorded line advances, a cut is generated in the line as shown by  1803   a  to  1803   c . A recording width to be handled by the corresponding head is determined by a line number, in which the cut is made, counted from the first line. For example, assuming that a gap  1803   a  is generated in a y-th line counted from the first line, a value obtained by subtracting a quotient obtained by dividing (y−1) by m from N, that is, n of the following equation (2) indicates the recording width to be handled by the corresponding head  1801   a . Additionally, several dots are required for image processing such that a joint between the adjacent heads is actually set to be inconspicuous, and therefore the recording width handled by the head  1801   a  is slightly larger than n.
 
 n=N− ( y −1)/ m  (where/denotes calculation of the quotient)  (2)
 
     According to the present invention, since a position of a recording head can be measured, a position of a recorded dot can be corrected to record an image without any distortion. 
     Moreover, since a pattern for measurement can be easily distinguished from an image for measurement recorded by the recording head, the position of each recording head can be easily measured. 
     Furthermore, since the pattern for measurement having a color different from that of ink recorded by the recording head is usable, the position of each recording head can be measured regardless of the color of the ink recorded by the recording head, and the position of the recorded dot can be corrected to record the image without any distortion. 
     Additionally, since the pattern for measurement can be easily distinguished from the image for measurement measured by the recording head, the position of each recording head can be easily measured. 
     Moreover, since the position of each recording head is measured a plurality of times, and an average value of results can be obtained, the position of each recording head can be obtained more correctly. 
     Furthermore, when Moire is generated by the pattern for measurement and the image for measurement recorded by the recording head, the position of each recording head can be measured with a high precision. 
     Additionally, wince the position of the dot can be measured more correctly by blur preventive processing of ink, the position of each recording head can be measured more correctly. 
     Moreover, since the type of the recording sheet or the pattern for measurement can be identified by an identification mark indicating the type of the pattern for measurement, switching between usual image recording and recording for measurement of a recorded dot position correction amount, or selecting of the image for measurement can be automatically performed. 
     Furthermore, since an attaching position of the recording head can be measured every time a rolled sheet is changed, the position of the recorded dot can be constantly corrected to record the image without any distortion. 
     Additionally, when the image produced in a measurement image data generation section is recorded on the supplied pattern for measurement, an adjustment amount of the recorded dot position is known. Therefore, when the position of a recorded image is accordingly corrected in a recorded image position correction section formed by the recording head, there can be provided an image recording apparatus capable of recording a high-quality image without any distortion. 
     Moreover, since the type of the supplied recording sheet can be identified in a mark identification section, there can be provided an image recording apparatus capable of automatically performing the switching between the usual image recording and the image recording for measurement of the recorded dot position correction amount, or the selecting of the image for measurement. 
     Furthermore, since the attaching position of the recording head can be measured every time the rolled paper is changed, there can be provided an image recording apparatus capable of constantly correcting the position of the recorded dot to record the image without any distortion. 
     Additionally, when the image produced/recorded in the measurement image data generation section is read in a direction different from the conveying direction of the recording sheet in an image reading section, the position of the image can be measured with a high resolution exceeding a basic resolution of the reading section, and therefore there can be provided an image recording apparatus capable of correcting the position of the recorded image with the high precision to record the image without any distortion. 
     Moreover, since an image rotation section, interval section, and average value calculation section are capable of measuring the position of the image with the high precision, there can be provided an image recording apparatus capable of correcting the position of the recorded image with the high precision to record the image without any distortion. 
     Furthermore, when Moire is generated by the pattern for measurement formed on the recording sheet and the image for measurement recorded by the recording head, and measured in a Moire fringe measurement section, there can be provided an image recording apparatus capable of correcting the position of each recording head with the high precision to record the image without any distortion. 
     Additionally, the position of the recorded dot formed by the recording head is corrected in accordance with an angle formed by a line direction and a conveying direction obtained from a first image recorded in a recording section to record an image capable of distinguishing the line direction of the recording head and a second image recorded in a recording section to record an image capable of distinguishing the conveying direction of the recording sheet. Accordingly, there can be provided an image recording apparatus capable of correcting the position of the recording head to record the image without any distortion. 
     Moreover, the position of the recorded dot formed by the recording head is corrected in accordance with the angle formed by the line direction and the conveying direction obtained from an image obtained by reading the first image recorded in the recording section to record the image capable of distinguishing the line direction of the recording head and the second image recorded in the recording section to record the image capable of distinguishing the conveying direction of the recording sheet by the image reading section. Accordingly, there can be provided an image recording apparatus capable of correcting the position of the recording head to record the image without any distortion. 
     Furthermore, there can be provided an image recording apparatus capable of easily determining a recording width to be handled by each of the plurality of recording heads by a positional relationship between a position fixed pattern included in the image produced by the measurement pattern generation section and a position moving pattern, which is recorded by two adjacent recording heads. 
     Additionally, there can be provided an image recording apparatus capable of easily determining the recording width to be handled by each of the plurality of recording heads by a positional relationship between opposite ends of a segment constituting the image produced by the measurement pattern generation section, which is recorded by two adjacent recording heads.