Printer varying pixel-shape to reduce jaggedness
AssigneeSharp Kabushiki Kaisha
InventorTomohiro Oikawa
Life of this patent
Estimating the term…
Abstract
In a laser printer having a serving semiconductor laser 14 as the printer engine part 3, the irradiation of a laser beam R, forming one pixel, is divided into a plurality of lighting times, and non-lighting times in response to clock horizontal synchronous signals CLKH1 and CLKH2, generated by a printer controller 2, so that the form of a light energy distribution, on a photosensitive body, for forming one pixel is made substantially trapezoidal. With this construction, the form of each dot of pixels composing an image is made substantially trapezoidal. This can lead to improving the image quality of any curve d portion and the sloped-line portion of the image, by reducing jaggedness.
Claims11
An image forming apparatus comprising:
- a photosensitive body having a surface on which a latent image, constituted by a plurality of pixels, is to be formed;
- exposing means for exposing said surface of said photosensitive body with light radiation;
- and
- exposing controlling means for controlling said exposing means in response to a picture signal indicating any character or graphic to be formed as a latent image on the surface of the photosensitive body, said exposing control means including
- shaping means for controlling said exposing means to form a latent image of a curved or sloped portion of a picture by dividing an exposing time for forming one pixel into a plurality of lighting periods, during which said exposing operation by said exposing means is to be performed, and a plurality of non-lighting periods, during which said exposing operation by said exposing means is to be suspended, and by so sequencing the lighting periods and the non-lighting periods, alternately, that a light energy distribution pattern of substantially trapezoid or rhomboid shape is formed on the photosensitive body.
An image forming apparatus comprising:
- a photosensitive body having a surface on which a latent image, constituted by a plurality of pixels, is to be formed;
- exposing means for exposing said surface of said photosensitive body with light radiation;
- and
- exposing controlling means for controlling said exposing means in response to a picture signal indicating any character or graphic to be formed as a latent image on the surface of the photosensitive body, said exposing control means including
- shaping means for controlling said exposing means to form a latent image of a curved or sloped portion of a picture by dividing an exposing time for forming one pixel into a plurality of lighting periods, during which said exposing operation by said exposing means is to be performed, and a plurality of non-lighting periods, during which said exposing operation by said exposing means is to be suspended, and by so sequencing the lighting periods and the non-lighting periods, alternately, that a light energy distribution pattern covering a square area for one pixel, and an adjacent diagonal quarter area of a pixel, adjacent to said one pixel, is formed on the photosensitive body.
Dependencies are inferred from the claim text.