RECORDING DEVICE DISCHARGE POSITION ADJUSTOR AND IMAGE FORMING APPARATUS INCORPORATING SAME

• US 20160121602A1
• Filed: 10/06/2015
• Published: 05/05/2016
• Est. Priority Date: 10/29/2014
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Inoue, Takahiro, Hayashi, Tomoaki, NAGASU, Tsuyoshi
• Granted Patent: US 10,427,423 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B41J 11/008 Controlling printhead for accurately positioning print image on printing material, e.g. with the intention to control the width of margins
• 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 2/2135 Alignment of dots
• 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

A recording device discharge position adjustor includes a recording device to discharge liquid droplets onto a recording medium; an edge detector unit to detect a lateral edge position of the recording medium in a direction perpendicular to a recording medium conveyance direction; a discharge position adjustor to adjust a discharge position of the liquid droplets from the recording device relative to the recording medium; a controller to adjust the discharge position using the discharge position adjustor; and an edge position converter to convert the edge position of the recording medium detected by the edge detector unit to an edge position at a position of the recording device, in which the controller adjusts the discharge position of the recording device by an adjustment amount corresponding to the edge position of the recording medium at the position of the recording device converted by the edge position converter.

Claims

1. A recording device discharge position adjustor comprising:

a recording device to discharge liquid droplets onto a recording medium;

an edge detector unit to detect a lateral edge position of the recording medium in a direction perpendicular to a recording medium conveyance direction;

a discharge position adjustor to adjust a discharge position of the liquid droplets from the recording device relative to the recording medium;

a controller to adjust the discharge position using the discharge position adjustor; and

an edge position converter to convert the edge position of the recording medium detected by the edge detector unit to an edge position at a position of the recording device,

wherein the controller adjusts the discharge position of the recording device by an adjustment amount corresponding to the edge position of the recording medium at the position of the recording device converted by the edge position converter.

2. The recording device discharge position adjustor as claimed in claim 1,

wherein the edge detector unit comprises:

an upstream edge detector disposed upstream of the recording device in the recording medium conveyance direction; and

a downstream edge detector disposed downstream of the recording device in the recording medium conveyance direction,

wherein the edge position converter converts, based on an upstream edge position of the recording medium detected by the upstream edge detector and a downstream edge position of the recording medium detected by the downstream edge detector, the upstream edge position of the recording medium to an edge position of the recording medium at a position of the recording device.

3. The recording device discharge position adjustor as claimed in claim 2, wherein the edge position converter coverts the upstream edge position based on a skew amount between the upstream edge detector and the downstream edge detector obtained at the upstream edge position and the downstream edge position.

4. The recording device discharge position adjustor as claimed in claim 2, further comprising:

a recording medium feed device to convey the recording medium;

a recording medium conveyance amount detector to detect a conveyance amount of the recording medium by the recording medium feed device;

an edge detection position phase matching device to detect a displacement amount of an identical edge position of the recording medium by the upstream edge detector and the downstream edge detector based on the conveyance amount of the recording medium detected by the recording medium conveyance amount detector;

a first noise canceller to cancel noise from the upstream edge detector and the downstream noise detector;

an edge displacement amount detector to detect the displacement amount of the identical edge position of the recording medium between the upstream edge detector and the downstream edge detector based on a difference between the upstream edge position and the downstream position; and

a second noise canceller to cancel noise from the edge displacement amount detector.

5. The recording device discharge position adjustor as claimed in claim 1,

wherein the discharge position adjustor comprises a moving device to move the recording device laterally, and the adjustment amount is a movement amount of the recording device by the moving device.

6. An image forming apparatus comprising:

a plurality of recording devices to discharge liquid droplets onto a recording medium to record an image on the recording medium, disposed along a recording medium conveyance direction;

a plurality of edge detectors to detect a lateral edge position of the recording medium in a direction perpendicular to the recording medium conveyance direction;

a discharge position adjustor to adjust a discharge position of the liquid droplets relative to the recording medium, from at least one of the recording devices; and

the recording device discharge position adjustor as claimed in claim 1.

7. A line head unit position correction device comprising:

a line head unit to discharge liquid droplets onto a recording medium to record an image on the recording medium;

an edge sensor to detect a lateral edge position of the recording medium in a direction perpendicular to a recording medium conveyance direction;

an actuator to adjust a discharge position of the liquid droplets from the line head unit relative to the recording medium;

a controller to adjust the discharge position using the actuator; and

a sheet edge detector to convert the edge position of the recording medium detected by the edge sensor to an edge position of the recording medium at a position of the line head unit,

wherein the controller adjusts the discharge position by an adjustment amount corresponding to the edge position of the recording medium at the position of the line head unit converted by the sheet edge detector.