Patent ID: 7771009
Filing Date: 2010-08-10
Classification: B41J

Abstract:
1. An image recording apparatus for recording images to a recording medium with a line recording head in which a plurality of image-recording elements are arrayed to have an effective recording width in a lengthwise direction of the line recording head, comprising: a recording medium conveyance device which conveys the recording medium in a recording medium conveyance direction relatively to the line recording head; a width detection device for detecting a width of the recording medium in a recording medium widthwise direction orthogonal to the recording medium conveyance direction; a recording head arrangement device for turning and positioning the line recording head so that the line recording head is in at least one of an orthogonal position where the lengthwise direction of the line recording head is substantially orthogonal to the recording medium conveyance direction, and an inclined position where the lengthwise direction of the line recording head is inclined at a predetermined angle with respect to the recording medium conveyance direction; and a control device which controls the line recording head, the recording medium conveyance device and the recording head arrangement device, wherein when the width detection device detects that the width of the recording medium is substantially the same as the effective recording width of the line recording head, the control device controls the recording head arrangement device to position the line recording head in the orthogonal position, and controls the line recording head and the recording medium conveyance device to record an image onto the recording medium at a first image resolution per unit surface area while conveying the recording medium at a first conveyance velocity relatively to the line recording head positioned in the orthogonal position, and wherein when the width detection device detects that the width of the recording medium is less than the effective recording width of the line recording head, the control device controls the recording head arrangement device to position the line recording head in the inclined position, and controls the line recording head and the recording medium conveyance device to record an image onto the recording medium at a second image resolution per unit surface area while conveying the recording medium at a second conveyance velocity relatively to the line recording head positioned in the inclined position, the control device maintaining the second image resolution per unit surface area substantially the same as the first image resolution per unit surface area by setting the second conveyance velocity higher than the first conveyance velocity to increase a dot pitch in the recording medium conveyance direction to compensate for a decrease of a dot pitch in the recording medium widthwise direction caused by positioning the line recording head in the inclined position.