Optical Scanning Device and Printing Apparatus

A printing apparatus comprising:

• a printing unit including a photosensitive material;
• and
• an optical scanning device comprising:
• an emission unit which emits a light beam;
• an oscillating mirror which deflects the light beam to reciprocate on the photosensitive material in a main scanning direction;
• and
• a controller which controls the emission unit to be on and off to form a pattern of dots in each cell of a plurality of cells defined on the photosensitive material, each cell being composed of a plurality of pixels, the pattern being formed according to a gradation of the cell and based on a dot-concentrated threshold matrix,
• wherein the threshold matrix is defined such that the pattern of dots to be formed in the cell includes a plurality of pairs of adjacent dots in a sub-scanning direction, the sub-scanning direction being orthogonal to the main scanning direction,
• wherein, among the plurality of pairs of adjacent dots to be formed, a number of pairs of adjacent dots which are closer than an interval of adjacent ideal scanning lines is equal to a number of pairs of adjacent dots which are further than the interval, and
• wherein the printing unit forms an image on the scanned photosensitive material and transfers the image onto a printing medium.

An optical scanning device comprising:

• an emission unit which emits a light beam;
• an oscillating mirror which deflects the light beam to reciprocate on a scanning surface, which is moved in a first direction, in a first way and a second way opposite to the first way along a second direction orthogonal to the first direction;
• a controller which controls the emission unit to selectively emit the light beam to form a pattern of dots in each cell of a plurality of cells defined on the scanning surface, the pattern being formed according to a gradation of the cell and based on a threshold matrix,
• wherein the threshold matrix is defined such that the pattern of dots to be formed in the cell includes a pair of adjacent dots in the first direction,
• wherein, among the plurality of adjacent dots, the number of pairs of adjacent dots to be formed by the light beam through a reciprocation from the first way to the second way is equal to the number of pairs of dots to be formed by the light beam through a reciprocation from the second way to the first way.

An optical scanning device comprising:

• an emission unit which emits a light beam;
• an oscillating mirror which deflects the light beam to reciprocate on a scanning surface in a main scanning direction;
• and
• a controller which controls the emission unit to be on and off to form a pattern of dots in each cell of a plurality of cells defined on the scanning surface, each cell being composed of a plurality of pixels, the pattern being formed according to a gradation of the cell and based on a dot-concentrated threshold matrix method,
• wherein the pattern of dots in each cell is determined such that the pattern of dots to be formed in the cell includes a plurality of pairs of adjacent dots in a sub-scanning direction, the sub-scanning direction being orthogonal to the main scanning direction, and
• wherein, among the plurality of pairs of adjacent dots to be formed, a number of pairs of adjacent dots which are closer than an interval of adjacent ideal scanning lines is equal to a number of pairs of adjacent dots which are further than the interval.