Method and apparatus for exposing printing plates using light emitting diodes

The apparatus of 3, wherein the wavelength range includes UV wavelengths.

A method for exposing a printing plate having a front, printing side and a back, non-printing side, the printing plate comprising a photosensitive material activated by exposure to radiation, the method comprising:

• providing a plurality of light-emitting diodes (LEDs) arranged in one or more arrays, the plurality of LEDs comprising at least two sets of LEDs, each set having an emission spectrum different from a corresponding emission spectrum of at least one other set, the one or more arrays spaced a pre-defined distance from the printing plate;
• and
• irradiating the back, non-printing side of the printing plate with the emission spectra of the at east two sets of LEDs simultaneously.

A method for exposing a printing plate having a front, printing side and a back, non-printing side, the printing plate comprising a photosensitive material activated by exposure to radiation, the method comprising:

• (a) providing a plurality of light-emitting diodes (LEDs) arranged in one or more arrays, the plurality of LEDs comprising at least two sets of LEDs, each set having an emission spectrum different from a corresponding emission spectrum of at least one other set, the one or more arrays spaced a pre-defined distance from the printing plate;
• and
• (b) controlling exposure time of the one or more arrays, exposure intensity of the one or more arrays, or a combination thereof, to spectrally shape the radiation received by the plate.