Systems and methods for printing data on a substrate including a color-changeable material are provided. One system includes a processing circuit and a device including an energy source. At least a portion of a printed publication is printed on the substrate using a commercial printing press based on fixed data. The device including the energy source is configured to add variable data to the substrate. The processing circuit is configured to receive the variable data and to control the energy source to change a color of the color-changeable material based on the variable data to provide at least a portion of the printed publication. The processing circuit is configured to control the energy source to change the color of the color-changeable material in-line with a flow of the substrate through one of a printing line, a finishing line, or a packaging line of the commercial printing press.

An optical print head comprises a first light emitting element row, a second light emitting element row, a lens array, a first drive circuit and a second drive circuit. The first light emitting element row includes the arrangement of first light emitting elements. The second light emitting element row includes second light emitting elements arranged in parallel with the first light emitting element row. The lens array concentrates light emitted by the first light emitting elements and the second light emitting elements. The first drive circuit drives each first light emitting element with an identical first current value. The second drive circuit drives each second light emitting element with an identical second current value different from the first current value.

An image forming apparatus includes a light emitting chip and at least one processor. The light emitting chip includes a plurality of light emitting elements, a DAC outputting a voltage corresponding to a setting value, and a circuit unit that supplies a current to the plurality of light emitting elements based on the voltage. At least one processor is configured to set the setting value such that one light emitting element included among the plurality of light emitting elements emits light of a predetermined amount, and correct image data pieces that respectively correspond to the plurality of light emitting elements based on first correction data for correcting amounts of light respectively emitted by the plurality of light emitting elements. The circuit unit supplies a current to each of the plurality of light emitting elements based on the corrected image data pieces.

A print engine includes a printer module for printing image data in a plurality of different print modes, wherein each print mode has an associated line print time. A data interface receives image data and associated metadata for a print job from a pre-processing system, the metadata including print mode metadata. A digital memory stores a plurality of pulse timing functions, each pulse timing function corresponding to one of the line print times associated with the plurality of print modes. A metadata interpreter interprets the metadata and determines the print mode to be used to print the image data. A printer module controller controls the printer module to print the image data using the pulse timing function corresponding to the line print time associated with the print mode, wherein each light source is activated for a pulse count corresponding to a pixel code value of an associated image pixel.

A print engine includes a printer module for printing image data in a plurality of different print modes, wherein each print mode has an associated line print time. A data interface receives image data and associated metadata for a print job from a pre-processing system, the metadata including print mode metadata. A digital memory stores a plurality of pulse timing functions, each pulse timing function corresponding to one of the line print times associated with the plurality of print modes. A metadata interpreter interprets the metadata and determines the print mode to be used to print the image data. A printer module controller controls the printer module to print the image data using the pulse timing function corresponding to the line print time associated with the print mode, wherein each light source is activated for a pulse count corresponding to a pixel code value of an associated image pixel.

An optical PH includes: a plurality of current-driven light emitting elements that are arranged in a line-shaped region; a controller that outputs a control voltage instructing an amount of a drive current to be supplied to each of the light emitting elements; and a plurality of drivers that correspond one-to-one with the light emitting elements, and each supply the drive current to a corresponding one of the light emitting elements, wherein the drivers each operate as one of: a high-voltage referring driver that supplies the drive current according to a voltage difference between the control voltage and a reference voltage higher than the control voltage; and a low-voltage referring driver that supplies the drive current according to a voltage difference between the control voltage and a reference voltage lower than the control voltage.

An image forming apparatus includes a light emitting element group including a plurality of light emitting elements disposed at first intervals in a first direction, and configured to emit optical beams based on image data, a lens array including a plurality of lenses disposed at second intervals different from the first intervals in the first direction and configured to focus or condense the light emitted from the light emitting element group, and a halftone processing unit configured to perform halftone processing by using a dither matrix corresponding to a relative positional relationship between the plurality of light emitting elements and the plurality of lenses to generate the image data.

An optical print head comprises a first light emitting element row, a second light emitting element row, a lens array, a first drive circuit and a second drive circuit. The first light emitting element row includes the arrangement of first light emitting elements. The second light emitting element row includes second light emitting elements arranged in parallel with the first light emitting element row. The lens array concentrates light emitted by the first light emitting elements and the second light emitting elements. The first drive circuit drives each first light emitting element with an identical first current value. The second drive circuit drives each second light emitting element with an identical second current value different from the first current value.

An optical print head including light emitting elements, drivers, setters, a detector, and a generator. The detector is for detecting a noise component superimposed on a luminance signal, on transmission circuitry for transmitting the luminance signal from a setter to a driver, in a state in which the setter is outputting the luminance signal. The generator, for each light emitting element due to emit light in a line subsequent to a line for which the detector detected the noise component, generates and causes a setter corresponding to the light emitting element to output an adjusted luminance signal such that the light emitting element emits a light emission amount according to image data in a state in which the noise component detected by the detector is to superimposed on the adjusted luminance signal.

An optical print head comprises a first light emitting element row, a second light emitting element row, a lens array, a first drive circuit and a second drive circuit. The first light emitting element row includes the arrangement of first light emitting elements. The second light emitting element row includes second light emitting elements arranged in parallel with the first light emitting element row. The lens array concentrates light emitted by the first light emitting elements and the second light emitting elements. The first drive circuit drives each first light emitting element with an identical first current value. The second drive circuit drives each second light emitting element with an identical second current value different from the first current value.