Recording apparatus and recording position correcting method

Claim 2

A recording apparatus for forming an image by means of main scanning as a reciprocating operation of a recording head and sub-scanning as a relative moving operation between the recording head and a recording medium in a direction different from the main scanning direction, comprising: image formation means for forming a reference image at a first predetermined position on the recording medium during a forward direction main scanning of the recording head, the reference image extending in a sub-scanning direction, while forming particular images at second predetermined positions on the recording medium during the forward direction main scanning and a reverse direction main scanning of the recording head, wherein the first predetermined position is different from the second predetermined positions; image detection means for performing main scanning on the recording medium to detect the reference image and the particular images formed during the forward direction main scanning and reverse direction main scanning; measuring means for measuring an image interval in the main scanning direction between the reference image and each of the particular images formed during each of the forward direction main scanning and reverse direction main scanning, based on output from said image detection means; and data processing means for calculating the amount of offset between a recording position of the particular images formed during the forward direction main scanning and another recording position of the particular images formed during the reverse direction main scanning, based on measurements carried out by said measuring means.

Claim 3

A recording apparatus as claimed in claim 1 , wherein said image detection means has a sensor placed on a carriage for allowing the recording head to carry out main scanning in the forward and reverse directions.

Claim 4

A recording apparatus as claimed in claim 1 , wherein said measuring means has means for generating a reference clock and means for measuring the interval by counting said reference clock between a point of time at which said image detection means detects, through main scanning, the particular images formed during the forward direction main scanning and a point of time at which said image detection means detects the reference image through main scanning and between a point of time at which said image detection means detects, through main scanning, the particular images formed during the reverse direction main scanning and a point of time at which said image detection means detects the reference image through main scanning.

Claim 5

A recording apparatus as claimed in claim 3 , wherein said reference clock generation means is also used as means for generating a clock for defining recording timings for the recording head.

Claim 6

A recording apparatus as claimed in claim 1 , wherein said image detection means detects a quantity of reflected light resulting from irradiation of the recording medium with light, and has a sensor for indicating a change in the quantity of reflected light depending on whether the images are formed on the recording medium.

Claim 7

A recording apparatus as claimed in claim 5 , wherein said measuring means measures the interval by measuring a time interval at which the quantity of reflected light changes while moving said sensor at a constant speed in the main scanning direction relative to the particular images, and multiplying the time interval by the speed.

Claim 8

A recording apparatus as claimed in claim 1 , further comprising means for correcting recording data or timings for recording the image on the recording medium, based on the amount of offset of the recording positions determined by said data processing means.

Claim 9

A recording apparatus as claimed in claim 1 , wherein the recording head is a head for performing recording by ejecting ink.

Claim 10

A recording apparatus as claimed in claim 8 , wherein the recording head has heating elements for generating thermal energy to make the ink to film-boil, as an energy used for ejecting the ink.

Claim 11

A recording apparatus for forming an image by means of main scanning executed by a plurality of recording heads and sub-scanning as a relative moving operation between the recording heads and a recording medium in a direction different from the main scanning direction, comprising: image formation means for forming a reference image at a first predetermined position on the recording medium during a forward direction main scanning of said plurality of recording heads, the reference image extending in a sub-scanning direction, while forming particular images at second predetermined positions on the recording medium during the forward direction main scanning and a reverse direction main scanning of the plurality of recording heads, wherein the first predetermined position is different from the second predetermined positions; image detection means for performing scanning on the recording medium to detect the reference image and the particular images formed by the plurality of recording heads; measuring means for measuring an image interval between the particular images formed by the plurality of recording heads, and for measuring another image interval in the main scanning direction between the reference image and each of the predetermined images formed during each of the forward direction main scanning and reverse direction main scanning, based on output from said image detection means; and data processing means for calculating the amounts of offset of recording positions of the particular images formed by the plurality of recording heads, based on measurements carried out by said measuring means.

Claim 12

A recording apparatus for forming an image by means of main scanning executed by a plurality of recording heads and sub-scanning as a relative moving operation between the recording heads and a recording medium in a direction different from the main scanning direction, comprising: image formation means for forming a reference image at a first predetermined position on the recording medium during a forward direction main scanning of said plurality of recording heads, the reference image extending in a sub-scanning direction, while forming particular images at second predetermined positions on the recording medium during the forward direction main scanning and a reverse direction main scanning of the plurality of recording heads, wherein the first predetermined position is different from the second predetermined positions; image detection means for performing scanning on the recording medium to detect the reference image and the particular images formed by the plurality of recording heads; measuring means for measuring an image interval between the particular images formed by the plurality of recording heads, and for measuring another image interval in the main scanning direction between the reference image and each of the predetermined images formed during each of the forward direction main scanning and reverse direction main scanning, based on output from said image detection means; and data processing means for calculating the amounts of offset of recording positions of the particular images formed by the plurality of recording heads, based on measurements carried out by said measuring means.

Claim 13

A recording apparatus as claimed in claim 10 , wherein said image detection means has a sensor placed on one carriage for integrally holding the plurality of recording heads for main scanning or one of a plurality of carriages for individually holding the plurality of recording heads for main scanning.

Claim 14

A recording apparatus as claimed in claim 10 , wherein said measuring means has means for generating a reference clock and means for measuring the intervals by counting said reference clock between a point of time at which said image detection means detects, through main scanning, each of the particular images formed by each of the plurality of recording heads and a point of time at which said image detection means detects the reference image through main scanning.

Claim 15

A recording apparatus as claimed in claim 12 , wherein said reference clock generation means is also used as means for generating a clock for defining recording timings for the recording heads.

Claim 16

A recording apparatus as claimed in claim 10 , wherein said image detection means detects a quantity of reflected light resulting from irradiation of the recording medium with light, and has a sensor for indicating a change in said quantity of reflected light depending on whether the particular images are formed on the recording medium.

Claim 17

A recording apparatus as claimed in claim 14 , wherein said measuring means measures the intervals by measuring a time interval at which said quantity of reflected light changes while moving said sensor at a constant speed relative to the particular images, and multiplying the time interval by said speed.

Claim 18

A recording apparatus as claimed in claim 10 , further comprising means for correcting recording data or timings for recording the image on the recording medium, based on the amount of offset of the recording positions determined by said data processing means.

Claim 19

A recording apparatus as claimed in claim 10 , wherein each one of the recording heads is a head for performing recording by ejecting ink.

Claim 20

A recording apparatus as claimed in claim 17 , wherein each one of the recording heads has heating elements for generating thermal energy to make the ink to film-boil, as an energy used for ejecting the ink.

Claim 21

A recording apparatus for forming an image by means of main scanning executed by a plurality of recording heads and sub-scanning as a relative moving operation between the recording heads and a recording medium in a direction different from the main scanning direction, comprising: image formation means for forming a reference image at a first predetermined position on the recording medium during a forward or reverse direction main scanning of one of the recording heads, the reference image extending in the main scanning direction, while forming particular images at second predetermined positions on the recording medium in the sub-scanning direction by using the plurality of recording heads, the first predetermined position being different from the second predetermined positions; image detection means for performing sub-scanning on the recording medium to detect the reference image and the particular images formed by the recording heads; and measuring means for measuring an interval in the sub-scanning direction between the reference image and each of the particular images formed by each of the plurality of recording heads, based on output from said image detection means; and data processing means for calculating the amounts of offset of the recording positions of the particular images formed by the plurality of recording heads, based on measurements carried out by said measuring means.

Claim 22

A recording apparatus for forming an image by means of main scanning executed by a plurality of recording heads and sub-scanning as a relative moving operation between the recording heads and a recording medium in a direction different from the main scanning direction, comprising: image formation means for forming a reference image at a first predetermined position on the recording medium during a forward or reverse direction main scanning of one of the recording heads, the reference image extending in the main scanning direction, while forming particular images at second predetermined positions on the recording medium in the sub-scanning direction by using the plurality of recording heads, the first predetermined position being different from the second predetermined positions; image detection means for performing sub-scanning on the recording medium to detect the reference image and the particular images formed by the recording heads; and measuring means for measuring an interval in the sub-scanning direction between the reference image and each of the particular images formed by each of the plurality of recording heads, based on output from said image detection means; and data processing means for calculating the amounts of offset of the recording positions of the particular images formed by the plurality of recording heads, based on measurements carried out by said measuring means.

Claim 23

A recording apparatus as claimed in claim 19 , wherein said image detection means has a sensor placed on one carriage for integrally holding the plurality of recording heads for main scanning or one of a plurality of carriages for individually holding the plurality of recording heads for main scanning, and sets said carriage at a position in the main scanning direction at which said sensor detects the reference image and the particular images during sub-scanning of the recording medium.

Claim 24

A recording apparatus as claimed in claim 19 , wherein said measuring means has means for generating a reference clock and means for measuring the intervals by counting said reference clock between a point of time at which said image detection means detects, through sub-scanning, each of the particular images formed by each of the plurality of recording heads and a point of time at which said image detection means detects the reference image through sub-scanning.

Claim 25

A recording apparatus as claimed in claim 21 , wherein said reference clock generation means is also used as means for generating a clock for defining recording timings for the recording heads.

Claim 26

A recording apparatus as claimed in claim 19 , wherein a drive source for said sub-scanning performs rotating motions, and wherein the particular images are formed at a position corresponding to integral multiples of a travel distance obtained by a single rotation of the drive source.

Claim 27

A recording apparatus for forming an image by means of main scanning as a reciprocating operation of a recording head and sub-scanning as a relative moving operation between the recording head and a recording medium in a direction different from the main scanning direction, comprising: image formation means for forming a reference image at a first predetermined position on the recording medium during a forward direction main scanning of the recording head, the reference image extending in a sub-scanning direction, while forming particular images at second predetermined positions on the recording medium during the forward direction main scanning and a reverse direction main scanning of the recording head, wherein the first predetermined position is different from the second predetermined positions; image detection means for performing main scanning on the recording medium to detect the reference image and the particular images formed during the forward direction main scanning and reverse direction main scanning; and data processing means for determining a center position of particular images in the main scanning direction from detection start and end positions of the particular images associated with main scanning by said image detection means, and calculating the amount of offset between a recording position of the particular images formed during the forward direction main scanning and another recording position of the particular images formed during the reverse direction main scanning, based on the main-scanning direction center positions of the particular images formed in the forward direction main scanning and reverse direction main scanning.

Claim 28

A recording apparatus for forming an image by means of main scanning as a reciprocating operation of a recording head and sub-scanning as a relative moving operation between the recording head and a recording medium in a direction different from the main scanning direction, comprising: image formation means for forming a reference image at a first predetermined position on the recording medium during a forward direction main scanning of the recording head, the reference image extending in a sub-scanning direction, while forming particular images at second predetermined positions on the recording medium during the forward direction main scanning and a reverse direction main scanning of the recording head, wherein the first predetermined position is different from the second predetermined positions; image detection means for performing main scanning on the recording medium to detect the reference image and the particular images formed during the forward direction main scanning and reverse direction main scanning; and data processing means for determining a center position of particular images in the main scanning direction from detection start and end positions of the particular images associated with main scanning by said image detection means, and calculating the amount of offset between a recording position of the particular images formed during the forward direction main scanning and another recording position of the particular images formed during the reverse direction main scanning, based on the main-scanning direction center positions of the particular images formed in the forward direction main scanning and reverse direction main scanning.

Claim 29

A recording apparatus as claimed in claim 24 , wherein said image detection means detects a quantity of reflected light resulting from irradiation of the recording medium with light, and has a sensor for indicating a change in said quantity of reflected light depending on whether an image is formed on the recording medium.

Claim 30

A recording apparatus as claimed in claim 24 , further comprising means for correcting recording data or timings for recording an image on the recording medium, based on the amount of offset of the recording positions determined by said data processing means.

Claim 31

A recording apparatus as claimed in claim 24 , wherein the recording head is a head for performing recording by ejecting ink.

Claim 32

A recording apparatus as claimed in claim 27 , wherein the recording head has heating elements for generating thermal energy to make the ink to film-boil, as an energy used for ejecting the ink.

Claim 33

A recording apparatus for forming an image by means of main scanning executed by a plurality of recording heads and sub-scanning as a relative moving operation between the recording heads and a recording medium in a direction different from the main scanning direction, comprising: image formation means for forming a reference image at a first predetermined position on the recording medium during a forward or reverse direction main scanning of one of the recording heads, the reference image extending in the sub-scanning direction, while forming particular images at second predetermined positions on the recording medium by using the plurality of recording heads, wherein the first predetermined position is different from the second predetermined positions; image detection means for scanning the recording medium to detect the reference image and the particular images formed by the plurality of recording heads; and data processing means for determining a center position of the particular images in a scanning direction of said image detection means, from detection start and end positions of the particular images associated with scanning by said image detection means, and calculating the amount of offset between recording positions of the particular images formed by the plurality of recording heads, based on the center positions of the particular images formed by the plurality of recording heads.

Claim 34

A recording apparatus for forming an image by means of main scanning executed by a plurality of recording heads and sub-scanning as a relative moving operation between the recording heads and a recording medium in a direction different from the main scanning direction, comprising: image formation means for forming a reference image at a first predetermined position on the recording medium during a forward or reverse direction main scanning of one of the recording heads, the reference image extending in the sub-scanning direction, while forming particular images at second predetermined positions on the recording medium by using the plurality of recording heads, wherein the first predetermined position is different from the second predetermined positions; image detection means for scanning the recording medium to detect the reference image and the particular images formed by the plurality of recording heads; and data processing means for determining a center position of the particular images in a scanning direction of said image detection means, from detection start and end positions of the particular images associated with scanning by said image detection means, and calculating the amount of offset between recording positions of the particular images formed by the plurality of recording heads, based on the center positions of the particular images formed by the plurality of recording heads.

Claim 35

A recording apparatus as claimed in claim 29 , wherein said image formation means forms the reference image at the predetermined position on the recording medium during the forward or reverse direction main scanning of one of the recording heads, the reference image extending in the main scanning direction, while forming particular images at the second predetermined positions on the recording medium in the sub-scanning direction using each of the plurality of recording heads, wherein the first predetermined position is different from that the second predetermined positions; wherein said image detection means performs sub-scanning on the recording medium to detect the reference image and the particular images formed by the recording heads; and wherein said data processing means calculates the amount of offset based on the distance between the center position in said sub-scanning direction of each of the particular images formed by a corresponding one of the plurality of recording heads and the center position of the reference image in the sub-scanning direction.

Claim 36

A recording apparatus as claimed in claim 29 , wherein said image detection means detects a quantity of reflected light resulting from irradiation of the recording medium with light, and has a sensor for indicating a change in the quantity of reflected light depending on whether an image is formed on the recording medium.

Claim 37

A recording apparatus as claimed in claim 29 , further comprising means for correcting recording data or timings for recording an image on the recording medium, based on the amount of offset of the recording positions determined by said data processing means.

Claim 38

A recording apparatus as claimed in claim 29 , wherein each one of the recording heads is a head for performing recording by ejecting ink.

Claim 39

A recording apparatus as claimed in claim 33 , wherein each one of the recording heads has heating elements for generating thermal energy to make the ink to film-boil, as an energy used for ejecting the ink.

Claim 40

A recording apparatus for forming an image by allowing one or more recording heads to relatively scan a recording medium, comprising: image formation means for forming particular images at predetermined positions on the recording medium by means of a plurality of recording operations performed by the one or more recording heads; image detection means for detecting the particular images formed by each of the plurality of recording operations, said image detection means having a sensor for detecting a quantity of reflected light resulting from irradiation of the recording medium with light and indicating a change in the quantity of reflected light depending on a rate at which an image is present within a detection range; and data processing means for setting the sensor at an identical position in a scanning direction in a boundary portion of each of the particular images on the recording medium that are formed by each of the plurality of recording operations, in order to detect the quantity of light, and for calculating the amount of offset of recording positions of the images obtained by the plurality of recording operations based on the difference in the detected amount of reflected light.

Claim 41

A recording apparatus for forming an image by allowing one or more recording heads to relatively scan a recording medium, comprising: image formation means for forming particular images at predetermined positions on the recording medium by means of a plurality of recording operations performed by the one or more recording heads; image detection means for detecting the particular images formed by each of the plurality of recording operations, said image detection means having a sensor for detecting a quantity of reflected light resulting from irradiation of the recording medium with light and indicating a change in the quantity of reflected light depending on a rate at which an image is present within a detection range; and data processing means for setting the sensor at an identical position in a scanning direction in a boundary portion of each of the particular images on the recording medium that are formed by each of the plurality of recording operations, in order to detect the quantity of light, and for calculating the amount of offset of recording positions of the images obtained by the plurality of recording operations based on the difference in the detected amount of reflected light.

Claim 42

A recording apparatus as claimed in claim 35 , wherein in the boundary portion between a portion of the recording medium with an image formed therein and a portion with no image formed therein, said data processing means moves said sensor between at least two positions having different rates at which an image is present within the detection range, in order to calculate the amounts of offset of the recording positions of the images obtained by said plurality of recording operations, based on the quantities of reflected light at the two positions, the travel distance, and the difference.

Claim 43

A recording apparatus as claimed in claim 35 , wherein said recording apparatus forms the image by means of main scanning as a reciprocating operation of the one or more recording heads and sub-scanning as a relative moving operation between the one or more recording heads and the recording medium in a direction different from the main scanning direction, said plurality of recording operations being performed in the forward direction main scanning and reverse direction main scanning; wherein said image formation means forms the particular images at a theoretical identical position in said main scanning direction during each of the forward direction main scanning and reverse direction main scanning of the one or more recording heads; and wherein said data processing means sets said sensor at an identical position in said main scanning direction in the boundary portion of each of the particular images on the recording medium.

Claim 44

A recording apparatus as claimed in claim 35 , wherein said recording apparatus forms the image by means of main scanning executed by the one or more recording heads and sub-scanning as a relative moving operation between the one or more recording heads and a recording medium in a direction different from the main scanning direction, the plurality of recording operations being performed by main scanning using the one or more recording heads, wherein: said image formation means forms the particular images at a theoretical identical position in the main scanning direction by means of each of the one or more recording heads.

Claim 45

A recording apparatus as claimed in claim 35 , wherein said recording apparatus forms the image by means of main scanning executed by the one or more recording heads and sub-scanning as a relative moving operation between the one or more recording heads and a recording medium in a direction different from the main scanning direction, said plurality of recording operations being performed by sub-scanning using the one or more recording heads, wherein: said image formation means forms the particular images at a theoretical identical position in the sub-scanning direction by means of each of the one or more recording heads.

Claim 46

A recording apparatus as claimed in claim 35 , further comprising means for correcting recording data or timings for recording the image on the recording medium, based on the amount of offset of the recording positions determined by said data processing means.

Claim 47

A recording apparatus as claimed in claim 35 , wherein each one of the recording heads is a head for performing recording by ejecting ink.

Claim 48

A recording apparatus as claimed in claim 41 , wherein each one of the recording heads has heating elements for generating thermal energy to make the ink to film-boil, as an energy used for ejecting the ink.

Claim 49

A recording position correcting method with respect to a recording apparatus for forming an image by means of main scanning as a reciprocating operation of a recording head and sub-scanning as a relative moving operation between the recording head and a recording medium in a direction different from the main scanning direction, said method comprising the steps of: forming a reference image at a first predetermined position on the recording medium during a forward direction main scanning, the reference image extending in the sub-scanning direction, while forming particular images at second predetermined positions on the recording medium during the forward direction main scanning and a reverse direction main scanning of the recording head, wherein the first predetermined position is different from the second predetermined positions; detecting the reference image and the particular images formed during the forward direction main scanning and reverse direction main scanning, by using image detection means for main scanning on the recording medium; measuring an image interval in the main scanning direction between the reference image and each of the particular images formed during each of the forward direction main scanning and a reverse direction main scanning, based on output from said image detection means; and calculating the amount of offset between a recording position of the image formed during the forward direction main scanning and another recording position of the image formed during the reverse direction main scanning, based on measurements carried out by said measuring step.

Claim 50

A recording position correcting method with respect to a recording apparatus for forming an image by means of main scanning as a reciprocating operation of a recording head and sub-scanning as a relative moving operation between the recording head and a recording medium in a direction different from the main scanning direction, said method comprising the steps of: forming a reference image at a first predetermined position on the recording medium during a forward direction main scanning, the reference image extending in the sub-scanning direction, while forming particular images at second predetermined positions on the recording medium during the forward direction main scanning and a reverse direction main scanning of the recording head, wherein the first predetermined position is different from the second predetermined positions; detecting the reference image and the particular images formed during the forward direction main scanning and reverse direction main scanning, by using image detection means for main scanning on the recording medium; measuring an image interval in the main scanning direction between the reference image and each of the particular images formed during each of the forward direction main scanning and a reverse direction main scanning, based on output from said image detection means; and calculating the amount of offset between a recording position of the image formed during the forward direction main scanning and another recording position of the image formed during the reverse direction main scanning, based on measurements carried out by said measuring step.

Claim 51

A recording position correcting method with respect to a recording apparatus for forming an image by means of main scanning executed by a plurality of recording heads and sub-scanning as a relative moving operation between the recording heads and a recording medium in a direction different from the main scanning direction, said method comprising the steps of: forming a reference image at a first predetermined position on the recording medium during a forward direction main scanning of the recording heads, the reference image extending in a sub-scanning direction, while forming particular images at second predetermined positions on the recording medium during the forward direction main scanning and a reverse direction main scanning of the plurality of recording heads, wherein the first predetermined position is different from the second predetermined positions; detecting the reference image and the predetermined images formed by the plurality of recording heads by using image detection means for main scanning on the recording medium; measuring an interval between the particular images formed by the plurality of recording heads, based on output from the image detection means; measuring another interval in the main scanning direction between the reference image and each of the particular images formed during each of the forward direction main scanning and reverse direction main scanning, based on an output from the image detection means; and calculating the amounts of offset of recording positions of the images formed by the plurality of recording heads, based on measurements carried out by said measuring step.

Claim 52

A recording position correcting method with respect to a recording apparatus for forming an image by means of main scanning executed by a plurality of recording heads and sub-scanning as a relative moving operation between the recording heads and a recording medium in a direction different from the main scanning direction, said method comprising the steps of: forming a reference image at a first predetermined position on the recording medium during a forward direction main scanning of the recording heads, the reference image extending in a sub-scanning direction, while forming particular images at second predetermined positions on the recording medium during the forward direction main scanning and a reverse direction main scanning of the plurality of recording heads, wherein the first predetermined position is different from the second predetermined positions; detecting the reference image and the predetermined images formed by the plurality of recording heads by using image detection means for main scanning on the recording medium; measuring an interval between the particular images formed by the plurality of recording heads, based on output from the image detection means; measuring another interval in the main scanning direction between the reference image and each of the particular images formed during each of the forward direction main scanning and reverse direction main scanning, based on an output from the image detection means; and calculating the amounts of offset of recording positions of the images formed by the plurality of recording heads, based on measurements carried out by said measuring step.

Claim 53

A recording position correcting method with respect to a recording apparatus for forming an image by means of main scanning as a reciprocating operation of a recording head and sub-scanning as a relative moving operation between the recording head and a recording medium in a direction different from the main scanning direction, said method comprising the steps of: forming a reference image at a first predetermined position on the recording medium during a forward direction main scanning of the recording head, the reference image extending in a sub-scanning direction, while forming particular images at second predetermined positions on the recording medium during the forward direction main scanning and reverse direction main scanning of the recording head, wherein the first predetermined position is different from the second predetermined positions; detecting the reference image and the particular images formed during the forward direction main scanning and reverse direction main scanning, by using image detection means being main scanning on the recording medium; and determining a center position of the particular images in the main scanning direction from detection start and end positions of the particular images associated with main scanning by the image detection means, and calculating the amount of offset between a recording position of the particular images formed during the forward direction main scanning and another recording position of the particular images formed during the reverse direction main scanning, based on the main-scanning direction center positions of the particular images formed in the forward direction main scanning and reverse direction main scanning.

Claim 54

A recording position correcting method with respect to a recording apparatus for forming an image by means of main scanning as a reciprocating operation of a recording head and sub-scanning as a relative moving operation between the recording head and a recording medium in a direction different from the main scanning direction, said method comprising the steps of: forming a reference image at a first predetermined position on the recording medium during a forward direction main scanning of the recording head, the reference image extending in a sub-scanning direction, while forming particular images at second predetermined positions on the recording medium during the forward direction main scanning and reverse direction main scanning of the recording head, wherein the first predetermined position is different from the second predetermined positions; detecting the reference image and the particular images formed during the forward direction main scanning and reverse direction main scanning, by using image detection means being main scanning on the recording medium; and determining a center position of the particular images in the main scanning direction from detection start and end positions of the particular images associated with main scanning by the image detection means, and calculating the amount of offset between a recording position of the particular images formed during the forward direction main scanning and another recording position of the particular images formed during the reverse direction main scanning, based on the main-scanning direction center positions of the particular images formed in the forward direction main scanning and reverse direction main scanning.

Claim 55

A recording position correcting method with respect to a recording apparatus for forming a image by means of main scanning executed by a plurality of recording heads and sub-scanning as a relative moving operation between the recording heads and a recording medium in a direction different from the main scanning direction, said method comprising the steps of: forming a reference image at a first predetermined position on the recording medium during a forward or reverse direction main scanning of one of the recording heads, the reference image extending in a sub-scanning direction, while forming particular images at second predetermined positions on the recording medium by using the plurality of recording heads, wherein the first predetermined position is different from the second predetermined positions; detecting the reference image and the predetermined images formed by the plurality of recording heads image, by using detection means being scanning on the recording medium; and determining a center position of the particular images in a scanning direction of the image detection means, from detection start and end positions of the particular images associated with scanning by the image detection means, and calculating the amount of offset between recording positions of the particular images formed by the plurality of recording heads, based on the center positions of the particular images formed by the plurality of recording heads.

Claim 56

A recording position correcting method with respect to a recording apparatus for forming a image by means of main scanning executed by a plurality of recording heads and sub-scanning as a relative moving operation between the recording heads and a recording medium in a direction different from the main scanning direction, said method comprising the steps of: forming a reference image at a first predetermined position on the recording medium during a forward or reverse direction main scanning of one of the recording heads, the reference image extending in a sub-scanning direction, while forming particular images at second predetermined positions on the recording medium by using the plurality of recording heads, wherein the first predetermined position is different from the second predetermined positions; detecting the reference image and the predetermined images formed by the plurality of recording heads image, by using detection means being scanning on the recording medium; and determining a center position of the particular images in a scanning direction of the image detection means, from detection start and end positions of the particular images associated with scanning by the image detection means, and calculating the amount of offset between recording positions of the particular images formed by the plurality of recording heads, based on the center positions of the particular images formed by the plurality of recording heads.

Claim 57

A recording position correcting method with respect to a recording medium for forming an image by allowing one or more recording heads to relatively scan a recording medium, said method comprising the steps of: forming particular images at predetermined positions on the recording medium by means of a plurality of recording operations performed by the one or more recording heads; detecting the particular images formed by each of the plurality of recording operations, by using image detection means having a sensor for detecting a quantity of reflected light resulting from irradiation of the recording medium with light and indicating a change in the quantity of reflected light depending on a rate at which the image is present within a detection range; and setting said sensor at an identical position in a scanning direction in a boundary portion of each of the particular images on the recording medium that are formed by each of the plurality of recording operations, in order to detect the quantity of light, and calculating the amount of offset of recording positions of the images obtained by the plurality of recording operations based on the difference in the detected amount of reflected light.

Claim 58

A recording position correcting method with respect to a recording medium for forming an image by allowing one or more recording heads to relatively scan a recording medium, said method comprising the steps of: forming particular images at predetermined positions on the recording medium by means of a plurality of recording operations performed by the one or more recording heads; detecting the particular images formed by each of the plurality of recording operations, by using image detection means having a sensor for detecting a quantity of reflected light resulting from irradiation of the recording medium with light and indicating a change in the quantity of reflected light depending on a rate at which the image is present within a detection range; and setting said sensor at an identical position in a scanning direction in a boundary portion of each of the particular images on the recording medium that are formed by each of the plurality of recording operations, in order to detect the quantity of light, and calculating the amount of offset of recording positions of the images obtained by the plurality of recording operations based on the difference in the detected amount of reflected light.