Inkjet recording apparatus and recording medium movement control method

• US 20050035989A1
• Filed: 08/03/2004
• Published: 02/17/2005
• Est. Priority Date: 08/13/2003
• Status: Active Grant

• Current Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Original Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Inventors: Maekawa, Yoshikazu, Arakawa, Hiroaki
• Granted Patent: US 7,364,251 B2
• Time in Patent Office: Days
• US Class Current: 347/16
• CPC Class Codes: B41J 11/46 by marks or formations on the paper being fed
• CPC Class Codes: B41J 29/393 Devices for controlling or analysing the entire machine ; Controlling or analysing mechanical parameters involving printing of test patterns

Abstract

An inkjet recording apparatus including: a recording head; a recording medium moving section; a position information detecting section synchronized with a movement of the recording medium moving section; a mark recording section for recording a mark on the recording medium; a mark detecting section for detecting the mark recorded; an analog-to-digital conversion section for converting an output signal; and a control section for obtaining a reference mark position of the mark based on a signal outputted from the mark detecting section and the position information detected, and for determining the amount of recording medium movement on the basis of reference detection position of the mark; wherein analog-to-digital conversion is applied to the output signal from the mark detecting section to get a sampling data, in exact timing with an output of position information, and the control section calculates the reference detection position from the sampling data.

Claims

1. An inkjet recording apparatus comprising:

a recording head for discharging ink particles toward the recording medium;

a recording medium moving section for moving the recording medium in a transporting direction;

a position information detecting section for detecting the position information from the recording medium moving section, synchronized with a movement of the recording medium moving section;

a mark recording section for recording a predetermined mark on the recording medium;

a mark detecting section, arranged at a predetermined distance from the recording medium, for detecting the mark recorded by the mark recording section;

an analog-to-digital conversion section for converting an output signal from the mark detecting section; and

a control section for obtaining a reference mark position of the mark based on a signal outputted when the mark detecting section detects the mark and the position information detected by the position information detecting section, and for determining the amount of recording medium movement by the recording medium moving section, on the basis of reference detection position of the mark;

wherein the control section applies analog-to-digital conversion to the output signal from the mark detecting section to get a sampling data, in exact timing with an output of position information by the position information detecting section, and the control section calculates the reference detection position of the mark from the sampling data.

2. The inkjet recording apparatus of claim 1, wherein the analogue-to-digital conversion section stops the conversion of the output signal from the mark detecting section, when the control section has acquired sufficient sampling values to calculate a position corresponding to a peak value of the output signal from the mark detecting section.

3. The inkjet recording apparatus of claim 1, wherein the analogue-to-digital conversion section starts the conversion of the output signal from the mark detecting section, immediately before a time when the mark detecting section starts to detect the mark, the time being estimated by the control section.

4. The inkjet recording apparatus of claim 1, further comprising a filtering section for filtering output values from the analogue-to-digital conversion section.

5. The inkjet recording apparatus of claim 1, wherein the mark recording section simultaneously records a plurality of predetermined marks.

6. An inkjet recording apparatus comprising:

a recording head for discharging ink particles toward the recording medium;

a recording medium moving section for moving the recording medium in a transporting direction;

a position information detecting section for detecting the position information of the recording medium moving section, synchronized with a movement of the recording medium moving section;

a mark recording section for recording a predetermined mark on the recording medium;

a mark detecting section, arranged at a predetermined distance from the recording medium, for detecting the mark recorded by the mark recording section; and

a control section for obtaining a reference detection position of the mark based on a signal outputted when the mark detecting section detects the mark and the position information detected by the position information detecting section, and for determining the amount of recording medium movement by the recording medium moving section, on the basis of reference detection position of the mark;

wherein the inkjet recording apparatus further comprises a clamping section for clamping an output signal of the mark detecting section at a position immediately before a position where the mark is predicted to be detected by the position information detecting section, and at a portion where the mark and an image are not recorded on the recording medium.

7. The inkjet recording apparatus of claim 6, wherein the clamping section clamps the output signal of the mark detecting section at a maximum or minimum potential after the position immediately before the position where the position information detecting section is estimated to detect the mark.

8. The inkjet recording apparatus of claim 6, wherein the control section compares the output signal clamped by the clamping section to a predetermined potential to obtain a comparative signal;

reads respective position information corresponding to rising and decaying edges of the comparative signal, from the position information detecting section;

assumes an intermediate position between positions corresponding to the rising and decaying edges as the maximum output position; and

utilizes the maximum output position for the reference detection position of the mark.

9. The inkjet recording apparatus of claim 6, wherein the control section reads position information corresponding to a peak value of the output signal clamped by the clamping section from the position information detecting section, assumes a position corresponding to the peak value as the maximum output position, and utilizes the maximum output position for the reference detection position of the mark.

10. The inkjet recording apparatus of claim 6, wherein an output signal clamped by the clamping section is masked, except for a predetermined distance range from the position immediately before the mark is estimated to be detected.

11. An inkjet recording apparatus comprising:

a recording head for discharging ink particles toward the recording medium from a plurality of nozzles provided on the recording head;

a recording head moving section for moving the recording head in a main scanning direction;

a recording medium moving section for moving the recording medium in the sub-scanning direction perpendicular to the main scanning direction;

a position information detecting section for detecting the position information of the recording medium moving section, synchronized with a movement of the recording medium moving section; and

a mark detecting section, arranged at a predetermined distance from the recording medium, and moved by the recording head moving section together with the recording head, for detecting the mark recorded by the mark recording section;

wherein an amount of recording medium movement by the recording medium moving section is determined with reference to a position where the mark detecting section has detected a detection signal of the mark,

wherein the mark recording section is arranged at a position with an interval from the recording head not shorter than the accelerated movement distance of the recording head by the recording head moving section;

the interval being a distance between a detecting position of the mark detecting section and a position of one of the plurality of nozzles used for recording the predetermined mark, in the main scanning direction.

12. The inkjet recording apparatus of claim 11, wherein mark detecting sections are arranged on both ends of the recording head in the main scanning direction.

13. An inkjet recording apparatus comprising:

a recording head for discharging ink particles toward the recording medium from a plurality of nozzles provided on the recording head;

a recording head moving section for moving the recording head in a main scanning direction;

a recording medium moving section for moving the recording medium in the sub-scanning direction perpendicular to the main scanning direction;

a position information detecting section for detecting position information of the recording medium moving section, synchronized with a movement of the recording medium moving section;

a mark recording section for recording a predetermined mark on the recording medium in a predetermined timing;

a mark detecting section, arranged at a predetermined distance from the recording medium, for detecting the mark recorded by the mark recording section;

a target moving distance calculation section for calculating a target moving distance of the recording medium, with reference to a position detected by the position information detecting section when the mark detecting section has detected a detection signal of the mark;

an estimated moving distance storage section for storing an estimated moving distance estimated in advance as the target moving distance of the recording medium;

a comparing section for making comparison between the target moving distance calculated by the target moving distance calculation section when the mark detecting section has detected the detection signal, and the estimated moving distance stored in the estimated moving distance storage section;

a switching section for switching the moving distance of the recording medium by the recording medium moving section to either the target moving distance calculated by the target moving distance calculation section or to the estimated moving distance stored in the estimated moving distance storage section, based on the result of comparison by the comparing section.

14. The inkjet recording apparatus of claim 13, wherein the switching section switch the moving distance by the recording medium moving section to the estimated moving distance when, as a result of the comparison by the comparing section, the target moving distance calculated by the target distance calculation section is smaller, by more than a predetermined value, than the estimated moving distance stored in the estimated moving distance storage section.

15. The inkjet recording apparatus of claim 13, further comprising an updating section for updating the estimated moving distance stored in the estimated moving distance storage section based on the target moving distance calculated by the target moving distance calculating section, in cases where the switching section has switched the moving distance of the recording medium by the recording medium moving section to the target moving distance calculated by the target moving distance calculating section.

16. The inkjet recording apparatus of claim 15, wherein the updating section restricts the target moving distance for updating the estimated moving distance to the target moving distance, which has a difference of not exceeding a predetermined value from the estimated moving distance before updating.

17. The inkjet recording apparatus of claim 13, wherein the estimated moving distance stored in the estimated moving distance storage section comprises distance values corresponding to each type of the recording medium and to each recording mode of the inkjet recording apparatus.

18. A recording medium movement control method comprising the steps of:

moving the recording medium by a recording medium moving section in a transporting direction;

detecting the position information from the recording medium moving section, synchronized with a movement of the recording medium moving section;

recording a predetermined mark on the recording medium in a predetermined timing;

detecting the mark by a mark detecting section arranged at a certain distance from the recording medium; and

applying analogue-to-digital conversion to an output signal from the mark detecting section; and

obtaining a reference mark position of the mark based on a signal outputted when the mark detecting section detects the mark, and the position information detected; and

determining an amount of recording medium movement by the recording medium moving section, on the basis of a reference detection position of the mark;

wherein in order to get a sampling data, the analogue-to-digital conversion is applied to an output signal from the mark detecting section in exact timing with the output of position information, and the reference detection position of the mark is calculated from the sampling data.

19. A recording medium movement control method comprising the steps of:

moving the recording medium by a recording medium moving section in a transporting direction;

detecting position information from the recording medium moving section, synchronized with a movement of the recording medium moving section;

recording a predetermined mark on the recording medium in a predetermined timing;

detecting the mark by a mark detecting section arranged at a certain distance from the recording medium; and

obtaining a reference mark position of the mark based on a signal outputted when the mark detecting section detects the mark, and the position information detected; and

determining an amount of recording medium movement by the recording medium moving section, on the basis of a reference detection position of the mark;

wherein the recording medium movement control method further comprises the step of clamping the output signal of the mark detecting section at a position immediately before a position where the mark is predicted to be detected by the position information, and at a portion where the mark and an image are not recorded on the recording medium.

20. A recording medium movement control method comprising the steps of:

moving the recording medium by a recording medium moving section in a sub-scanning direction with respect to a recording head, moved in the main scanning direction, for discharging ink particles to the recording medium;

recording a predetermined mark on the recording medium by discharging ink particles from at least one of the plurality of nozzles in the process of the recording head being moved by the recording head moving section;

in a predetermined timing;

detecting the mark recorded by the mark recording section by a mark detecting section arranged at a certain distance from the recording medium and moved by the recording head moving section together with the recording head;

determining the amount of recording medium movement by the recording medium moving section, with reference to a position where the mark detecting section has detected a detection signal of the mark;

wherein the mark recording section is arranged at a position with an interval from the recording head not shorter than the accelerated movement distance of the recording head by the recording head moving section;

the interval being a distance between a detecting position of the mark detecting section and a position of one of the plurality of nozzles used for recording the predetermined mark, in the main scanning direction.

21. A recording medium movement control method comprising the steps of:

moving the recording medium in a sub-scanning direction with respect to a recording head, moved in the main scanning direction, for discharging ink particles to the recording medium from a plurality of nozzles;

recording a predetermined mark on the recording medium in a predetermined timing;

detecting the mark by a mark detecting section arranged at a certain distance from the recording medium; and

controlling a movement of the recording medium with reference to a position where the mark has been detected by the mark detecting section;

calculating a target moving distance of the recording medium, with reference to the position of the mark, when the mark has been detected by the mark detecting section;

comparing the calculated target moving distance and a estimated moving distance stored in advance as the target moving distance of the recording medium, when the mark has been detected; and

switching the moving distance of the recording medium to either the calculated target moving distance or the estimated moving distance, based on the result of comparison.

22. A recording medium movement control method of claim 21, wherein the moving distance of the recording medium is switched to the estimated moving distance when, as a result of the comparing, the target moving distance calculated is smaller, by more than a predetermined value, than the estimated moving distance stored.

23. The recording medium movement control method of claim 21, wherein the estimated moving distance is updated based on the target moving distance calculated, in cases where the moving distance of the recording medium is switched to the target moving distance calculated.

24. The recording medium movement control method of claim 23, wherein the target moving distance to be used for updating the estimated moving distance is restricted to the target moving distance, which has a difference of not exceeding a predetermined value from the estimated moving distance before updating.

25. The recording medium movement control method of claim 21, wherein, the estimated moving distance comprises distance values corresponding to each type of the recording medium and to each recording mode of the inkjet recording apparatus.