INKJET RECORDING APPARATUS

• US 20160136947A1
• Filed: 11/03/2015
• Published: 05/19/2016
• Est. Priority Date: 11/19/2014
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: HOMMI, Masashi
• Granted Patent: US 9,440,431 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B41J 11/0095 Detecting means for copy material, e.g. for detecting or sensing presence of copy material or its leading or trailing end
• CPC Class Codes: B41J 2/0451 for detecting failure, e.g. clogging, malfunctioning actuator
• CPC Class Codes: B41J 2/04586 controlling heads of a type not covered by groups B41J2/04575 - B41J2/04585, or of an undefined type
• CPC Class Codes: B41J 2/2146 for line print heads
• CPC Class Codes: B41J 25/001 Mechanisms for bodily moving print heads or carriages parallel to the paper surface

Abstract

An inkjet recording apparatus includes a plurality of line heads disposed along a conveyance direction of a recording sheet and including a plurality of nozzles to discharge ink droplets, the plurality of nozzles disposed in a direction perpendicular to the conveyance direction of the recording sheet; a plurality of edge sensors corresponding to respective line heads, to detect a lateral edge of the recording sheet; a plurality of actuators corresponding to the respective line heads, to move to the respective line heads laterally in a sheet width direction; a head position adjustor to determine movement amounts of the respective line heads in accordance with outputs of the plurality of edge sensors; and a failure determiner to obtain outputs of the plurality of edge sensors simultaneously and identify a failure of the plurality of edge sensors based on a combination of the outputs from the plurality of edge sensors.

Claims

1. An inkjet recording apparatus comprising:

a plurality of line heads disposed along a conveyance direction of a recording sheet and including a plurality of nozzles to discharge ink droplets, the plurality of nozzles disposed in a direction perpendicular to the conveyance direction of the recording sheet;

a plurality of edge sensors corresponding to respective line heads of the plurality of line heads, to detect a lateral edge of the recording sheet;

a plurality of actuators corresponding to the respective line heads, to move to the respective line heads laterally in a sheet width direction;

a head position adjustor to determine movement amounts of the respective line heads in accordance with outputs of the plurality of edge sensors; and

a failure determiner to obtain outputs of the plurality of edge sensors simultaneously and identify a failure of the plurality of edge sensors based on a combination of the outputs from the plurality of edge sensors.

2. The inkjet recording apparatus as claimed in claim 1, wherein:

an output range of the plurality of edge sensors includes an abnormal range; and

the failure determiner identifies a failure based on whether the outputs from the plurality of edge sensors are within the abnormal range.

3. The inkjet recording apparatus as claimed in claim 2, wherein the failure determiner determines that the plurality of edge sensors has not failed and a conveyance position of the recording sheet has changed when all of the outputs from the plurality of edge sensors are within the abnormal range.

4. The inkjet recording apparatus as claimed in claim 2, wherein the failure determiner determines that one edge sensor of the plurality of edge sensors has failed when an output from the one edge sensor alone is within the abnormal range.

5. The inkjet recording apparatus as claimed in claim 2, wherein the failure determiner determines whether the outputs from the plurality of edge sensors are within the abnormal range based on a conveyance time period of the recording sheet from a farthest upstream edge sensor to a farthest downstream edge sensor of the plurality of edge sensors in the conveyance direction of the recording sheet.

6. The inkjet recording apparatus as claimed in claim 2, further comprising a memory to store a control table including a plurality of combination patterns based on a difference of determination results as to whether the outputs from the plurality of edge sensors are within the abnormal range and including a previously obtained determination result for each of the plurality of combination patterns,

wherein the failure determiner identifies a failure based on the control table.

7. The inkjet recording apparatus as claimed in claim 2, wherein the memory includes a flowchart previously generated and stored, and the failure determiner determines whether the outputs of plurality of edge sensors are within the abnormal range based on the flowchart.

8. The inkjet recording apparatus as claimed in claim 2, wherein the failure determiner determines that one edge sensor of the plurality of edge sensors has failed when an output of the one edge sensor is in a range different from a range of outputs of the other edge sensors.

9. The inkjet recording apparatus as claimed in claim 1, wherein the output range of the plurality of edge sensors includes a normal range and two abnormal ranges, one abnormal range set at an upper limit side of the normal range and a second abnormal range set at a lower limit side of the normal range.

10. The inkjet recording apparatus as claimed in claim 1, wherein the plurality of edge sensors is a plurality of reflection-type optical sensors.

11. The inkjet recording apparatus as claimed in claim 1, wherein the head position adjustor serves as the failure determiner.