Control system configured to correct variations in optical output of light emitting devices, image forming system, control method, and computer-readable recording medium

A control method for controlling an image forming device, the image forming device including a charging device, an image bearer to be charged by the charging device, a light-emitting device array including a plurality of light emitting devices, and a driver configured to cause the light emitting devices to emit light to form a latent image on the image bearer, the control method comprising:

• storing, at a first time, light-amount correction values for each of light emitting devices in a memory by,
• determining a pixel value of each pixel of a plurality of pixels in image data, the pixel value being a level of intensity of the pixel,
• determining the level of intensity of the pixel with a lowest level of intensity among the plurality of pixels,
• determining, for each of the plurality of pixels, differences between the level of intensity of a respective one of the plurality of pixels, and the level of intensity of the pixel with the lowest level of intensity, and
• storing the differences as the light-amount correction values such that each of the differences is associated with the respective one of the pixels,
• receiving, at a second time, a request to print the image data, the second time being after the first time;
• and
• printing, at the second time, the image data by,
• reading light-amount correction values from the memory;
• correcting a pixel value of each of the plurality of pixels in the image data by, for each of the plurality of pixels, reducing the pixel value associated with the respective one of the pixels by a reduction rate equal to one of the light amount correction values associated with the respective one of the pixels;
• and
• controlling the driver to cause each of the light emitting devices to emit light based on the image data for which a pixel value of each pixel has been corrected such that the level of intensity of each of the light emitting devices is equal to the lowest level of intensity among the light emitting devices.

A non-transitory computer-readable recording medium with an executable program stored thereon for controlling an image forming device, the image forming device including a charging device, an image bearer to be charged by the charging device, a light-emitting device array including a plurality of light emitting devices, and a driver configured to cause the light emitting devices to emit light to form a latent image on the image bearer, wherein the program is executable by a controller to configure the controller to perform:

• storing, at a first time, light-amount correction values for each of light emitting devices in a memory by,
• determining a pixel value of each pixel of a plurality of pixels in image data, the pixel value being a level of intensity of the pixel,
• determining the level of intensity of the pixel with a lowest level of intensity among the plurality of pixels,
• determining, for each of the plurality of pixels, differences between the level of intensity of a respective one of the plurality of pixels, and the level of intensity of the pixel with the lowest level of intensity, and
• storing the differences as the light-amount correction values such that each of the differences is associated with the respective one of the pixels;
• receiving, at a second time, a request to print the image data, the second time being after the first time;
• and
• printing, at the second time, the image data by,
• reading light-amount correction values from the memory;
• correcting a pixel value of each of the plurality of pixels in the image data by, for each of the plurality of pixels, reducing the pixel value associated with the respective one of the pixels by a reduction rate equal to one of the light amount correction values associated with the respective one of the pixels;
• and
• controlling the driver to cause each of the light emitting devices to emit light based on the image data for which a pixel value of each pixel has been corrected such that the level of intensity of each of the light emitting devices is equal to the lowest level of intensity among the light emitting devices.