JP2007028509A5 - - Google Patents

Claims (8)

A plurality of light beams emitted from each light emitting point of a light source unit having three or more light emitting points arranged linearly at a predetermined interval are deflected by the deflecting unit, and the plurality of light beams deflected by the deflecting unit Is imaged on the surface to be scanned by the imaging optical system, and the surface to be scanned is scanned with a plurality of light beams in the main scanning direction by the deflection operation of the deflecting means.
Among the plurality of scanning lines that scan the surface to be scanned, the distance between two scanning lines that are the farthest in the sub-scanning direction is measured by the measuring means, and the scanning line pitch interval in the sub-scanning direction is adjusted based on the result. A method for adjusting a scanning line pitch interval of a scanning optical device . A sequence of light emitting points in which n (n is an integer of 3 or more) light emitting points are linearly arranged at a predetermined interval, and m (m is an integer of 2 or more) is arranged in a direction orthogonal to the straight line. deflecting the plurality of light beams emitted from the light source means with deflection means, a plurality of light beams deflected by said deflecting means in the imaging optical system is focused on the surface to be scanned by the deflecting operation of said deflecting means When scanning the surface to be scanned in the main scanning direction with a plurality of light beams,
Among the plurality of scanning lines that scan the surface to be scanned, the distance between two scanning lines that are the farthest in the sub-scanning direction is measured by the measuring means, and the scanning line pitch interval in the sub-scanning direction is adjusted based on the result. A method for adjusting a scanning line pitch interval of a scanning optical device . A sequence of light emitting points in which n (n is an integer of 3 or more) light emitting points are linearly arranged at a predetermined interval, and m (m is an integer of 2 or more) is arranged in a direction orthogonal to the straight line. deflecting the plurality of light beams emitted from the light source means with deflection means, a plurality of light beams deflected by said deflecting means in the imaging optical system is focused on the surface to be scanned by the deflecting operation of said deflecting means When scanning the surface to be scanned in the main scanning direction with a plurality of light beams,
A first step of measuring a distance between two scanning lines farthest in the sub-scanning direction among a plurality of scanning lines scanning the surface to be scanned by a measuring unit;
Among the n scanning lines when the surface to be scanned is scanned with n light beams emitted from n light emitting points in the i-th column (i = 1, 2,..., m−1). Thus, the scanning line closest to the n scanning lines when the surface to be scanned is scanned with the n light beams emitted from the n light emitting points in the i + 1 column and the n light emission in the i + 1 column. Of the n scanning lines when scanning the surface to be scanned with n light beams emitted from a point, the n light beams emitted from n light emitting points in the i-th column are scanned with the light beam. A second step of measuring the distance from the scanning line closest to the n scanning lines when scanning on the surface with the measuring means,
First, the scanning line pitch interval adjusting method of a scanning optical apparatus and adjusting the sub-scanning direction of the scanning line pitch on the basis of the results of the measurements in the second step. 4. The distance between the two most distant scanning lines is measured at at least two points within a scanning effective width, and the scanning line pitch interval is adjusted based on the result. 2. A method for adjusting a scanning line pitch interval of the scanning optical device according to 1) . On the surface to be scanned, the distance between two scanning lines that are most separated in the sub-scanning direction is L (mm), the number of scanning lines is Pn, and the pixel density in the sub-scanning direction on the surface to be scanned is A (dot / inch) over the entire scanning effective width,
2/3 × (Pn−1) × 25.4 / A <L <4/3 × (Pn−1) × 25.4 / A
However, Pn = n × m
5. The method of adjusting a scanning line pitch interval of a scanning optical device according to claim 1, wherein the scanning line pitch interval is adjusted so as to satisfy the above. The pixel density scanning line pitch interval adjusting method of a scanning optical apparatus according to claim 5, characterized in that at least 1200 dpi. On the surface to be scanned, an interval between two scanning lines that are most separated in the sub-scanning direction is L (mm), and an imaging point that draws the first scanning line at the same time is adjacent to the first scanning line. The angle formed between the second scanning line and the straight line connecting the two scanning lines and the imaging point is θ, and the imaging point drawing the first scanning line at the same time is adjacent to the first scanning line. When the length of the straight line connecting the image forming point that draws the scanning line is a,
0.9L / (mn-1) <(L-am (n-1) sin θ) / (m-1) <1.1L / (mn-1)
4. The scanning line pitch interval adjusting method for a scanning optical apparatus according to claim 2, wherein the scanning line pitch interval is adjusted so as to satisfy the above. 8. The scanning line pitch interval adjustment is performed by rotating the light source means around the optical axis with the center of a line segment connecting two light emitting points farthest apart as a rotation center. A scanning line pitch interval adjusting method of the scanning optical device according to Item.