Inkjet recording apparatus

• US 20040075708A1
• Filed: 10/09/2003
• Published: 04/22/2004
• Est. Priority Date: 10/18/2002
• Status: Active Grant

• Current Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Original Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Inventors: Arakawa, Hiroaki
• Granted Patent: US 7,118,187 B2
• Time in Patent Office: Days
• US Class Current: 347/19
• 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 having therein:

a recording head,

a recording head moving device,

a recording medium feeding device,

a mark recording device to print a predetermined mark on the recording medium by ejecting ink droplets, and

a mark detecting device to detect the mark printed by the mark recording device, arranged at a predetermined distance position from the recording medium, and is fed together with the recording head,

wherein the movement amount of the recording medium is determined on the basis of the position where the mark detecting device detects detection signals.

Claims

1. An inkjet recording apparatus, comprising:

a recording medium feeding device to feed a recording medium on a platen;

a recording head having a plurality of nozzles to eject ink droplets onto the recording medium;

a recording head moving device to move the recording head in a direction perpendicular to a feeding direction of the recording medium;

a mark recording device to record a mark which is perpendicular to the feeding direction of the recording medium, on the recording medium by the ink droplets jetted from at least one of the nozzles of the recording head, while the recording head is moved by the recording head moving device; and

a mark detecting device which is moved together with the recording head and detects the mark;

wherein a feeding amount of the recording medium is determined on the basis of a position on which the mark detecting device detects the mark.

2. The inkjet recording apparatus of claim 1, wherein the recording medium feeding device feeds the recording medium at a high speed to a position which is adjacent to a position on which the mark will be detected by the mark detecting device, and further feeds the recording medium at a low speed from the position adjacent to the mark.

3. The inkjet recording apparatus of claim 1, further comprising:

A memory device to store the feeding amount of the recording medium, wherein when the mark detecting device can not detect the mark as it normally does, the recording medium is fed on the basis of the previous feeding amount stored in the memory device.

4. The inkjet recording apparatus of claim 1, wherein a feeding distance of the recording medium until the mark detecting device detects the mark, is less than the feeding amount which the recording medium must advance fundamentally.

5. The inkjet recording apparatus of claim 1, further comprising:

a feeding amount detecting device which detects the feeding amount of the recording medium,

wherein the recording medium feeding device has a changeover device which can switch to a case in which the feeding amount of the recording medium is determined on the basis of the position where the mark detecting device detects a detection signal, or another case in which the feeding amount of the recording medium is determined on the basis of only the detection signal from the feeding amount detecting device.

6. The inkjet recording apparatus of claim 1, wherein the mark detecting device works for both

a recording medium detecting device which detects whether or not the recording medium exists, and

a bi-directional position detecting device which performs bi-directional positioning of the recording head in relation to the recording medium.

7. The inkjet recording apparatus of claim 1,

wherein the mark recording device records a plurality of marks at a time, on the recording medium by the ink droplets ejected from a plurality of the different nozzles,

the mark detecting device detects the plurality of marks,

the recording medium feeding device calculates and assumes a position which gives the smallest detection error from the distance interval calculated by the nozzle pitch of the recording head, referring to the position of each mark detected by the mark detecting device,

and wherein the feeding amount is determined on the basis of the calculated and assumed position.

8. The inkjet recording apparatus of claim 1, wherein the mark is printed at the point located outside the image printing area.

9. The inkjet recording apparatus of claim 1, wherein the mark is printed on an area which is, in the recording medium feeding direction, upstream of the area on which the main scanning of the recording head performs the recording.

10. The inkjet recording apparatus of claim 9,

wherein the recording head is composed of a plurality of heads, and among the plurality of these heads, the head which has the nozzle for printing the mark on the recording medium by ejecting ink droplets, is shifted for one nozzle interval from the other heads, in the recording medium feeding direction.

11. The inkjet recording apparatus described of claim 10, wherein the mark recording device allows the mark printing nozzle to eject ink for a distance necessary for printing the mark.

12. The inkjet recording apparatus described of claim 10, wherein the mark recording device prevents the nozzles adjacent to the mark printing nozzle from ejecting ink.

13. The inkjet recording apparatus of claim 1, wherein the mark detecting device is composed of a light reflection type sensor, having:

a light emitting element which emits a detecting light beam onto the recording medium;

a condenser lens which condenses the detecting light beam emitted from the light emitting element; and

a light receiving sensor which detects the light beam reflected from the surface of the recording medium on which the detecting light beam is focused by the condenser lens,

wherein the light emitting element and the optical axis of the condenser lens are angled to the surface of the recording medium in the direction perpendicular to the feeding direction of the recording medium.

14. The inkjet recording apparatus of claim 1, wherein the mark detecting device is formed of a reflection type sensor, having:

a light emitting element which emits detecting light onto the recording medium;

a condenser lens which focuses the detecting light emitted from the light emitting element; and

a light receiving sensor which detects light reflected from the surface of the recording medium on which the detecting light is focused by the condenser lens, wherein the light emitting element and the optical axis of the condenser lens are approximately perpendicular to the surface of the recording medium.

15. The inkjet recording apparatus of claim 7, wherein the mark detecting device is formed of a light reflection type sensor, having:

a light emitting element which emits detecting light onto the recording medium;

a condenser lens which condenses the detecting light emitted from the light emitting element; and

a light receiving sensor which detects light reflected from the surface of the recording medium on which the detecting light is focused by the condenser lens,

wherein the light emitting element and the optical axis of the condenser lens are approximately perpendicular to the surface of the recording medium, and

wherein the light emitting element, condenser lens and the recording medium are arranged, satisfying the inequality k×

b<

a×

m, where “

k”

is the length of the light emitting element in the sub-scanning direction, “

a”

is the distance between the condenser lens and the surface of the recording medium, and “

b”

is the pitch width in the sub-scanning direction.

16. The inkjet recording apparatus described of claim 1, wherein the mark is yellow.

17. The inkjet recording apparatus of claim 16, wherein a light emitting element is a blue LED, and a light detecting element is sensitive to blue.

18. The inkjet recording apparatus described of claim 1, wherein the mark is printed by one scan and is perpendicular to the feeding direction of the recording medium.