JP2010264685A - Apparatus and method for forming image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a defect such as color unevenness in color printing by detecting that a carriage inclines. <P>SOLUTION: The image forming apparatus which includes a carriage 1 which can move and scan alone in a main scan direction and a carriage 2 which can move and scan as a unit with the carriage 1 in the main scan direction includes an inclination detecting means 4 which detects both a second inclination as an inclination in the main scan direction of the carriage 1 when the carriage 1 and the carriage 2 are moved in a connection state and a third inclination as an inclination in the main scan direction of the carriage 2, and a distinguishing means 15 which distinguishes the inclination of the carriage by comparison between a first inclination as an inclination in the main scan direction of the carriage 1 when the carriage 1 is separately moved and the second inclination, and/or comparison between the first inclination and the third inclination. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and an image forming method. More specifically, the present invention relates to an image forming apparatus and an image forming method suitable for detecting the inclination of a carriage on which a recording head is mounted.

  As an image forming apparatus such as a printer, a facsimile machine, a copying machine, and a multifunction machine of these, for example, an apparatus including a recording head composed of a liquid discharging head that discharges liquid droplets of a recording liquid (liquid) is used. However, the material is not limited, and a recording medium (hereinafter also referred to as ink) is conveyed while conveying a recording medium, a recording medium, a transfer material, recording paper, and the like. There is a so-called ink jet type image forming apparatus that performs image formation (hereinafter, recording, printing, printing, and printing are also used synonymously) attached to a sheet.

  For example, in a color ink jet printer, a liquid ejection head (hereinafter also referred to as a recording head or a head) of four or more colors of black (K), yellow (Y), cyan (C), and magenta (M) or a nozzle array A carriage equipped with a head is scanned and printed. However, in such a color printer, when monochrome printing is mainly used, color ink is wasted due to idle discharge of color ink and recovery processing of the color head to prevent clogging due to drying of the color head. There is a problem. As a result, even if monochrome printing is attempted, there may be a case where the color ink runs out and printing becomes impossible.

  To deal with such a problem, for example, Patent Document 1 includes a carriage (first carrier) on which a color head group is mounted and a carriage (second carrier) on which a black head is mounted. In color printing, two carriages are provided. In the monochrome printing, only the second carrier is scanned and printed, and the first carrier is moisturized so that the head is not dried.

  On the other hand, as a technique for detecting the inclination of a nozzle row of a recording head, for example, in Patent Document 2, an optical axis of detection light is formed between a light emitting element and a light receiving element, and ink droplets ejected from the nozzle of the recording head Disclosed is a technique for calculating the inclination of the nozzle array of a recording head based on the amount of deviation between the position of the recording head and the position of the droplet detecting means. Has been. Patent Documents 3 to 5 also disclose techniques for calculating the inclination of the nozzle array of the recording head.

  However, as described in Patent Document 1, in the configuration in which two carriages are divided and combined, in the case of color printing, since the two carriages are combined and scanned, the positional relationship of the respective heads in the combined state, that is, The right angle of the nozzle row with respect to the main scanning direction of the carriage becomes a problem.

  For example, FIG. 19 shows a case where the first carriage 1 and the second carriage 2 moving on the guide member (guide rod 3) are perpendicular to the main scanning direction (no inclination). On the other hand, FIG. 20 shows the case where only the first carriage 1 is open at the leading end side and is not perpendicular to the main scanning direction (with inclination), and FIG. 22 shows the case where the leading end sides of the first carriage 1 and the second carriage 2 are opened and are not perpendicular to the main scanning direction. FIG. 23 shows the case where the guide member sides of the first carriage 1 and the second carriage 2 are opened. 24 shows that the first carriage 1 and the second carriage 2 rotate clockwise and is not perpendicular to the main scanning direction, and FIG. 25 shows that the first carriage 1 and the second carriage 2 are counterclockwise. The case where the rotation is not perpendicular to the main scanning direction is shown.

  The guide members arranged in the main scanning direction as shown in FIG. 20 to FIG. 25 when the positional relationship between the two carriages is such that the carriage is not properly coupled or the carriage is displaced during the coupling or separation process. And a carriage moving on the guide member, the print position of the black head and the print position of the color head are shifted during color printing, resulting in problems such as color unevenness. Will occur.

  Here, in the configuration in which the two carriages are divided and combined, in the case of monochrome printing, only the first carriage scans, so that the inclination of the head mounted on the carriage is adjusted by the techniques described in Patent Documents 2 to 5 above. Can be calculated.

  However, in the case of color printing, in the techniques described in Patent Documents 2 to 5, either the first carriage or the second carriage or both of them are tilted due to the coupling, or the state before the coupling It is impossible to detect whether the first carriage is tilted.

  Accordingly, the present invention compares the respective tilt detection results when the first carriage and the second carriage are moved in a combined state with reference to the tilt detected when the first carriage is moved alone. Another object of the present invention is to provide an image forming apparatus and an image forming method capable of detecting the inclination of the carriage which varies depending on the state of the carriage.

  In order to achieve such an object, an image forming apparatus according to a first aspect of the present invention includes a first carriage that can be moved and scanned independently in the main scanning direction, and a first carriage that can move and scan integrally with the first carriage in the main scanning direction. In an image forming apparatus including two carriages, a second inclination that is an inclination in the main scanning direction of the first carriage when the first carriage and the second carriage are moved in a coupled state, and a main scanning direction of the second carriage An inclination detection means for detecting a third inclination that is an inclination of the first carriage, and a first inclination and a second inclination that are inclinations in the main scanning direction of the first carriage when the first carriage is moved separately. And / or discriminating means for discriminating the inclination of the carriage based on the comparison between the first inclination and the third inclination.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the first inclination is detected by the inclination detecting means.

  According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the first carriage is moved after the first carriage is moved alone and the first inclination is detected by the inclination detecting means. Thus, the second carriage is coupled to the second carriage, the first carriage and the second carriage are moved in a coupled state, and the second and third inclinations are detected by the inclination detection means.

  According to a fourth aspect of the present invention, in the image forming apparatus according to the second aspect, the second carriage can be moved independently in the main scanning direction, and the inclination is detected by moving the first carriage alone. After the first inclination is detected by the means, the second carriage is moved and coupled with the first carriage, and the second inclination and the third inclination are detected by the inclination detection means.

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, an output unit that outputs a determination result of the determination unit is provided.

  According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the second to fifth aspects, the first carriage and the second carriage have a plurality of nozzle rows, and the tilt detecting means includes Tilt detection is performed using at least one nozzle row of one carriage and second carriage.

  According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the second to sixth aspects, the first carriage has a plurality of nozzle rows, and the tilt detecting means has a first tilt detection. Different nozzle rows are used for the nozzle row used for the nozzle row and the nozzle row used for the second inclination detection.

  According to an eighth aspect of the present invention, there is provided an image forming method comprising: a first carriage that can move and scan independently in the main scanning direction; and a second carriage that can move and scan integrally with the first carriage in the main scanning direction. An image forming method for an image forming apparatus, wherein the first carriage and the second carriage are moved in a coupled state, the second inclination being the inclination of the first carriage in the main scanning direction, and the second carriage main scanning. A tilt detection process for detecting a third tilt that is a tilt of the direction, and a first tilt and a second tilt that are tilts in the main scanning direction of the first carriage when the first carriage is moved separately. And / or a discrimination process for discriminating the inclination of the carriage based on the comparison between the first inclination and the third inclination.

  According to the present invention, when the first carriage moves alone, the first carriage and the second carriage are not normally coupled even if the carriage is not inclined and normal printing is possible. In such a case, by detecting that the carriage is tilted at the time of combination while repeating combination and separation, it is possible to prevent occurrence of problems such as color unevenness in color printing.

1 is an explanatory perspective view illustrating an example of an overall configuration of an image forming apparatus according to the present invention. 3 is an example of a functional block diagram of a control unit of the image forming apparatus. FIG. It is an example of the figure for demonstrating inclination detection processing (1st Embodiment). It is another example of the figure for demonstrating inclination detection processing (1st Embodiment). It is another example of the figure for demonstrating inclination detection processing (1st Embodiment). It is another example of the figure for demonstrating inclination detection processing (1st Embodiment). It is another example of the figure for demonstrating inclination detection processing (1st Embodiment). It is another example of the figure for demonstrating inclination detection processing (1st Embodiment). It is an example of the flowchart of an inclination detection process (1st Embodiment). It is an example of the figure for demonstrating inclination detection processing (2nd Embodiment). It is another example of the figure for demonstrating inclination detection processing (2nd Embodiment). It is another example of the figure for demonstrating inclination detection processing (2nd Embodiment). It is another example of the figure for demonstrating inclination detection processing (2nd Embodiment). It is another example of the figure for demonstrating inclination detection processing (2nd Embodiment). It is an example of the flowchart of inclination detection processing (2nd Embodiment). It is a figure for demonstrating the output of the 1st inclination K1 by inclination detection processing. It is a figure for demonstrating the output of the 2nd inclination K2 by inclination detection processing. It is a figure for demonstrating the output of the 3rd inclination K3 by inclination detection processing. It is an example of the schematic diagram which shows the case where the 1st carriage and the 2nd carriage are at right angles to the main scanning direction. It is an example of a schematic diagram showing a case where the first carriage is not perpendicular to the main scanning direction. It is an example of a schematic diagram showing a case where the second carriage is not perpendicular to the main scanning direction. It is an example of a schematic diagram showing a case where the first carriage and the second carriage are not perpendicular to the main scanning direction. It is another example of the schematic diagram which shows the case where the 1st carriage and the 2nd carriage are not perpendicular to the main scanning direction. It is another example of the schematic diagram which shows the case where the 1st carriage and the 2nd carriage are not perpendicular to the main scanning direction. It is another example of the schematic diagram which shows the case where the 1st carriage and the 2nd carriage are not perpendicular to the main scanning direction.

  Hereinafter, the configuration according to the present invention will be described in detail based on embodiments shown in the drawings.

1. Configuration of Image Forming Apparatus FIG. 1 is a perspective explanatory view showing an example of the entire configuration of an image forming apparatus (serial ink jet recording apparatus) according to the present embodiment. The image forming apparatus includes a support base 6 that supports an image forming apparatus main body (hereinafter, apparatus main body) 5.

  Inside the apparatus main body 5, a guide rod 3 and a guide rail 31 are spanned on both side plates (not shown), and a carriage 1 (first carriage) and a carriage 2 (second carriage) are provided on the guide rod 3 and the guide rail 31. Is held so as to be slidable in the arrow A direction (main scanning direction). The carriages 1 and 2 can be coupled by a coupling means 13 (not shown). If the coupling by the coupling means 13 is released, the carriage 1 can move alone. The carriage 2 performs scanning printing integrally in a state where it is coupled to the carriage 1 by the coupling means, but it is also preferable that the carriage 2 can be moved independently in the released state. Here, the coupling means 13 is not particularly limited as long as a known or new coupling means is used. For example, a coupling lever, an engagement pin, or the like can be used.

  The carriage 1 is mounted with recording heads 11 and 12 that eject black (K) ink droplets, and the carriage 2 is a recording that ejects ink droplets of yellow (Y), magenta (M), and cyan (C). Heads 21, 22, and 23 are mounted.

  The image forming apparatus scans and prints only the carriage 1 alone during monochrome printing, and scans and prints the carriages 1 and 2 together in a state of being coupled by the coupling means during color printing. Each recording head is integrally provided with a sub tank (not shown) for supplying ink to each recording head.

  The main scanning mechanism that moves and scans the carriages 1 and 2 is disposed on one side in the main scanning direction, a driving pulley 71 that is rotationally driven by the driving motor 7, and on the other side in the main scanning direction. The driven pulley 72 and a belt member 73 wound around the driving pulley 71 and the driven pulley 72 are provided. The driven pulley 72 is tensioned outward (in a direction away from the drive pulley 71) by a tension spring (not shown). In addition, the belt member 73 pulls the carriages 1 and 2 in the main scanning direction by being partly fixed and held by a belt fixing part provided on the back side of the carriages 1 and 2.

  An encoder sheet (not shown) is arranged along the main scanning direction of the carriages 1 and 2, and the main scanning position of the carriage is detected by reading the encoder sheet by an encoder sensor provided on the carriages 1 and 2. be able to.

  Among the main scanning areas on the carriages 1 and 2, in the recording area, the paper 8 is intermittently conveyed in the arrow B direction (sub scanning direction) perpendicular to the main scanning direction of the carriages 1 and 2 by a paper feed mechanism (not shown). Is done.

  In addition, a maintenance / recovery mechanism 9 that performs maintenance / recovery of the recording head is disposed in one end side region of the main scanning region. Further, a main cartridge 91 containing ink of each color to be supplied to a sub tank of the recording head is detachably attached to the recording apparatus main body 5 outside the carriage moving area in the main scanning direction or below the other end of the carriage moving area. It is attached to.

  Further, an inclination detecting means 4 for detecting the inclination of the carriage in the main scanning direction based on the ink ejection state between the maintenance / recovery mechanism 9 and the print area and perpendicular to the main scanning direction and below the head nozzle. Is arranged.

  The configuration of the tilt detection unit 4 is not particularly limited as long as the tilt of the nozzle array of the recording head can be detected as in the techniques described in Patent Documents 2 to 5. In the present embodiment, for example, a light emitting means 41 and a light receiving means 42 made of a laser, an LED or the like are provided, and ink is ejected from the nozzles when the recording head passes over the inclination detecting means 4 to Based on the change, the inclination of the carriage is detected. The optical axes of the light emitting means 41 and the light receiving means 42 (indicated by the alternate long and short dash line in FIGS. 3 and 4) are adjusted with reference to ink ejection from the recording head of the carriage 1 and then assembled to the main body of the image forming apparatus. It is preferable.

  In the image forming apparatus according to the present embodiment described above, the carriages 1 and 2 are moved in the main scanning direction, and the recording heads 11, 12, 21, 22, and 23 are used as image information while intermittently feeding the paper 8. A desired image can be formed on the paper 8 by ejecting the droplets by driving accordingly.

  FIG. 2 is a part of a functional block diagram of the image forming apparatus according to the present invention, and is a functional block diagram of a part related to carriage tilt detection control.

  The control unit 10 drives and controls a drive motor 7 and a conveyance motor (not shown) in order to form an image on the paper 8 based on the input printed image data. For example, a detection signal for detecting the positions of the carriages 1 and 2 is input via an encoder sensor, and the control unit 10 controls the movement positions and movement speeds of the carriages 1 and 2 based on the detection signals.

  The discriminating means 15 detects the inclination of the carriage in each carriage state (separated state or combined state) based on the carriage inclination detected by the inclination detecting means 4, and outputs the detection result via the control unit 10. Output to means 14.

  The output unit 14 is, for example, an operation panel of the image forming apparatus, and when the determination unit 15 detects the inclination of the carriage, displays that effect. The output means is not limited to the operation panel, and may be a sound generating means for generating a warning sound or an error message. It is also preferable to perform display on the operation panel and generation of a warning sound.

2. Inclination Detection Processing Details of the inclination detection processing and determination processing of the carriages 1 and 2 executed by the image forming apparatus according to the present embodiment will be described below with reference to FIGS. Note that the processing described below is preferably executed at the start of color printing, for example.

(First embodiment)
FIG. 3 is an explanatory diagram showing the carriage movement state of FIGS. 3 to 8, FIG. 9 is a flowchart, and FIGS. 16 to 18 are explanatory diagrams showing outputs of first to third inclinations K1 to K3 in the first embodiment. This will be described with reference to FIG.

  First, as shown in FIG. 3, the carriages 1 and 2 are in the home position (capping position) of the maintenance and recovery mechanism 9 as an initial state (S11). In this state, the carriage 1 is separated from the carriage 2 and is movable in the print area direction.

  Next, as shown in FIG. 4, the carriage 1 is separated and moved in the direction of the inclination detecting means 4. Here, when the carriage 1 moves to the vicinity of the inclination detecting means 4, the ink ejection is sequentially scanned with respect to the nozzle rows from the nozzles 11a to 11n of any recording head (the recording head 11 in this embodiment) of the carriage 1. A first inclination detection process is performed (S12).

  Here, the first inclination detection process (S12) will be described with reference to FIG. In the graphs shown in FIGS. 16 to 18, the x-axis indicates the main scanning position, the y-axis indicates the output (light output of the light receiving means 42), and the z-axis indicates the nozzle position.

  As shown in FIG. 16, when the ink droplet is detected by the inclination detecting means 4, the output from the inclination detecting means 4 by the ink droplet of the nozzle 11a has a peak at a certain position (main scanning position) in the main scanning direction. Similarly, the nozzles 11b,... 11n have a peak at a certain position in the main scanning direction of the output of the inclination detecting means 4 by ink droplets. The first inclination of the first carriage 1 can be obtained by connecting the peak positions of the outputs of the inclination detecting means 4 for the respective nozzles. In addition, since the calculation method of the said inclination is well-known as shown, for example in patent document 3, detailed description is abbreviate | omitted.

  Here, in the present embodiment, as described above, the optical axes of the light emitting means 41 and the light receiving means 42 are preliminarily adjusted on the basis of ink ejection from the head of the carriage 1 and assembled to the main body of the image forming apparatus. In principle, the first inclination K1 of the carriage 1 is perpendicular to the main scanning direction, that is, the value of X (main scanning position) is uniform as in the example shown in FIG. However, if the first inclination is calculated and it is detected that the first inclination is not perpendicular to the main scanning direction, an error message may be displayed on the output means 15 to that effect.

  After the first inclination is detected and stored in the storage means (RAM) of the image forming apparatus, the carriage 1 is returned to the home position and the carriage 1 and the carriage 2 are joined by the joining means 13 as shown in FIG. (S13).

  Next, the combined two carriages 1 and 2 are moved in the direction of the inclination detecting means 4 (S14). Here, as shown in FIG. 6, when the carriage 1 moves to the vicinity of the inclination detecting means 4, the second inclination detecting process (S15) while sequentially scanning ink discharge from the nozzles 11a of the head 11 of the carriage 1 to 11n. I do.

  As shown in FIG. 17, the second inclination K2 is detected by the second inclination detection process (S15) in the same manner as the first inclination detection method in the first inclination detection process (S12).

  Further, as shown in FIG. 7, when the carriage 2 moves to the vicinity of the inclination detecting means 4, the ink discharge is sequentially scanned from the nozzle 21a of one of the recording heads of the carriage 2 (the recording head 21 in this embodiment) to 21n. The third tilt detection process is performed while the process is performed (S16).

  As shown in FIG. 18, the third inclination K3 is detected by the third inclination detection process in the same manner as the first and second inclination detection methods in the first and second inclination detection processes (S12, S15). (S16).

  Next, the determination unit 15 compares the first inclination K1 and the second inclination K2, and compares the first inclination K1 and the third inclination K3 (S17: determination processing). Here, if K1 and K2 are not within the allowable error (substantially coincident), it can be determined that the carriage 1 is tilted in the coupled state. If K1 and K3 are not within the allowable error (substantially coincide), it can be determined that the carriage 2 is tilted in the coupled state. Accordingly, it is possible to detect the inclination of one carriage by performing at least one of the comparisons, but it is preferable to perform both comparisons together in order to detect both inclinations simultaneously.

  In the determination process (S17), in determining whether the carriage tilt is perpendicular to the main scanning direction (no tilt), the carriage tilt depends on factors such as mechanical accuracy and ink ejection accuracy. Strictly speaking, since there are many cases where the angle is not right, it is preferable to set a predetermined tolerance. In the present embodiment, for example, the allowable range is set in the main scanning direction with a nozzle width of 1/2 dot (about 20 μm) as the allowable range with reference to the first inclination K1 of the carriage 1 when not coupled. The position is determined to determine whether it is normal or abnormal.

  In the determination process (S17), when both the comparison results of the comparison between the first inclination K1 and the second inclination K2 and the comparison between the first inclination K1 and the third inclination K3 are substantially the same (S17). : Coincidence) can be determined that both the carriage 1 and the carriage 2 are perpendicular to the main scanning direction. Therefore, in this case, since it can be determined that printing is possible without causing a printing failure, the color printing operation may be started by moving to the printing area as shown in FIG. 8 (S18).

  On the other hand, if the comparison result between the first inclination K1 and the second inclination K2 is not substantially coincident, it can be determined that the carriage 1 is inclined with respect to the main scanning direction after the combination, and the first inclination K1 and the third inclination K1 are the same. If the comparison result with the inclination K3 is not substantially coincident, it can be determined that the carriage 2 is inclined with respect to the main scanning direction after the coupling.

  For example, as shown in FIG. 22, if the carriage 1 and the carriage 2 are tilted with respect to the main scanning direction after being combined in a letter C shape, the inclination K2 of the carriage 1 is the third of the second carriage 2 shown in FIG. The inclination K3 is obtained by the inclination detecting means 4 as shown in FIG. Here, since the inclinations K2 and K3 are not perpendicular to the main scanning direction, it can be determined that K1 ≠ K2 and K1 ≠ K3, and the carriage is inclined.

  If printing is performed from this state, there is a risk of printing failure as described above. Therefore, the image forming apparatus according to this embodiment includes an output unit 15 that notifies the user of the inclination of the carriage. The fact that the tilt has occurred is displayed on the operation panel, is notified to the user by a warning sound or an error message, or is displayed on the connected device or the like (S19).

  By doing so, the user who has recognized the abnormality can adjust the carriage inclination by the adjusting means or the like. Further, if it is visually confirmed that foreign matter is caught between the carriages, it can be removed.

  As described above, according to the first embodiment of the image forming apparatus according to the present invention, not only the inclination of the carriage 1 when the carriage 1 moves alone, but also the carriage 1 and the carriage 2 are normally coupled. If it is detected that the carriage is tilted during the coupling and the coupling and separation are repeated, and the tilt during the coupling is detected, the printing operation is not performed and the user is notified. In addition, the monochrome print quality for scanning alone with the carriage 1 and the color print quality for scanning the carriage 1 and the carriage 2 together can be kept equal, and the occurrence of problems such as color unevenness in color printing can be prevented. Further, since the carriage 2 is only operated by being coupled to the carriage 1, the carriage drive control can be simplified.

  The first first carriage tilt detection process (S12) shown in FIG. 4 does not have to be performed every time during color printing. In the operation after the first tilt K1 is temporarily stored in the storage device, the first carriage K is stored in the storage device. A comparison between the slope K1 and the slopes K2 and K3 may be performed.

  In the tilt detection process, any of the nozzle arrays of the heads of each carriage may be used. However, when there are a plurality of heads and nozzle arrays in each carriage, the tilt detection is performed for at least one nozzle array. Can be used to detect the inclination of the carriage. By doing so, the tilt detection control can be made more efficient, and waste of consumption of ink or the like can be reduced.

  In this case, for example, it is preferable to use a nozzle row of a color with a large amount of remaining ink in the inclination detection process. By doing so, it is possible to make the consumption with other inks uniform and make the head durability uniform.

  It is also preferable to use a different nozzle row for each inclination detection process. This is because the consumption of the ink head can be suppressed and the durability can be made uniform.

  In this case, for example, in the detection of the first inclination K1 and the second inclination K2 in the carriage 1, the detection of K1 is performed by the nozzle array of the head 11 and the detection of K2 is performed by the nozzle array of the head 12. good. By doing so, it is possible to prevent the head from drying and to make the ink consumption uniform.

(Second Embodiment)
Next, a second embodiment will be described with reference to an explanatory diagram illustrating a carriage moving state in FIGS. 10 to 14 and a flowchart in FIG. 15. Note that the description of the same points as in the first embodiment will be omitted.

  First, as shown in FIG. 10, the carriages 1 and 2 are in the home position of the maintenance and recovery mechanism 9 as an initial state (S21). Next, as shown in FIG. 11, the carriage 1 is separated and moved in the direction of the inclination detecting means 4. Here, when the carriage 1 moves to the vicinity of the inclination detecting means 4, the first inclination detecting process is performed while sequentially scanning the ink ejection for the nozzle rows from the nozzles 11a to 11n of the recording head 11 (S22).

  After the first inclination K1 is detected and stored in the storage means (RAM) of the image forming apparatus, as shown in FIG. 12, the position of the carriage 1 is left as it is, and the carriage 2 is moved in the direction of the print area, thereby combining means. 13 connects the carriage 1 and the carriage 2 (S23).

  Next, the second inclination detection process (FIG. 13, S24) and the third inclination detection process (FIG. 14, S25) are performed from the combined state to obtain the second inclination K2 and the third inclination K3. Further, a discrimination process (S26) is performed, and the start of printing operation (S27) or discrimination result output (S28) is performed based on the discrimination result.

  In the second embodiment described above, unlike the tilt detection process in the first embodiment, the efficiency of the process can be further improved by moving the carriage 2 independently. That is, according to the inclination detection process of the second embodiment, the first carriage does not return to the home position after detecting the inclination K1 of the first carriage alone, and therefore, compared with the inclination detection process of the first embodiment. Thus, it is possible to reduce the amount of processing and shorten the time until determination.

  The above-described embodiment is a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

  For example, in the above-described embodiment, a configuration has been described in which the carriage 1 (first carriage) is mounted with a recording head that discharges black ink, and the carriage 2 (second carriage) is mounted with a color head group that discharges color ink. However, the present invention is not limited to this, and even if a recording head that discharges color ink is mounted on both the first carriage and the second carriage, a recording head that discharges black ink is mounted on both the first carriage and the second carriage. Anyway.

DESCRIPTION OF SYMBOLS 1 1st carriage 2 2nd carriage 3 Guide rod 4 Inclination detection means 5 Apparatus main body 6 Support stand 7 Drive motor 8 Paper 9 Maintenance recovery mechanism 10 Control part (control means)
11, 12 Recording head 13 Coupling means 14 Operation section (output means)
15 Discriminating means 21, 22, 23 Recording head 31 Guide rail 41 Light emitting means 42 Light receiving means 71 Drive pulley 72 Followed pulley 73 Belt member 73
91 Main cartridge

JP-A-2-1327 Japanese Patent Laid-Open No. 2005-131887 JP 2007-130778 A JP 2008-105304 A JP 2007-45068 A

Claims (8)

In an image forming apparatus comprising: a first carriage that can be moved and scanned independently in the main scanning direction; and a second carriage that can be moved and scanned integrally with the first carriage in the main scanning direction.
A second inclination that is the inclination of the first carriage in the main scanning direction and a third inclination that is the inclination of the second carriage in the main scanning direction when the first carriage and the second carriage are moved in a coupled state. An inclination detecting means for detecting the inclination of
Comparison between the first inclination and the second inclination, which are inclinations in the main scanning direction of the first carriage when the first carriage is moved separately, and / or the first inclination and the third inclination. An image forming apparatus comprising: a discriminating unit that discriminates the inclination of the carriage by contrast with the inclination of the carriage.   The image forming apparatus according to claim 1, wherein the first inclination is detected by the inclination detection unit. After the first carriage is moved alone and the first inclination is detected by the inclination detecting means, the first carriage is moved and coupled with the second carriage,
3. The image forming apparatus according to claim 2, wherein the first carriage and the second carriage are moved in a coupled state, and the second inclination and the third inclination are detected by the inclination detection unit. . The second carriage can be moved independently in the main scanning direction,
After the first carriage is moved alone and the first inclination is detected by the inclination detection means, the second carriage is moved and coupled with the first carriage,
The image forming apparatus according to claim 2, wherein the second inclination and the third inclination are detected by the inclination detection unit.   5. The image forming apparatus according to claim 1, further comprising an output unit that outputs a determination result of the determination unit. The first carriage and the second carriage have a plurality of nozzle rows,
6. The image forming apparatus according to claim 2, wherein the tilt detection unit detects tilt using at least one nozzle row of the first carriage and the second carriage. 7. The first carriage has a plurality of nozzle rows,
7. The apparatus according to claim 2, wherein the inclination detection unit uses different nozzle arrays for a nozzle array used for the first inclination detection and a nozzle array used for the second inclination detection. 8. The image forming apparatus described. An image forming method for an image forming apparatus, comprising: a first carriage that can be moved and scanned independently in a main scanning direction; and a second carriage that can be moved and scanned integrally with the first carriage in the main scanning direction,
A second inclination that is the inclination of the first carriage in the main scanning direction and a third inclination that is the inclination of the second carriage in the main scanning direction when the first carriage and the second carriage are moved in a coupled state. An inclination detection process for detecting the inclination of
Comparison between the first inclination and the second inclination, which are inclinations in the main scanning direction of the first carriage when the first carriage is moved separately, and / or the first inclination and the third inclination. And a discrimination process for discriminating the inclination of the carriage by comparison with the inclination of the image.