Method and apparatus for correcting output light-amounts of spatial light modulator, image recording apparatus, and image recording method

An image recording method of recording an image on a recording material irradiated with light from a spatial light modulator while moving said light relatively to said recording material, wherein

• said spatial light modulator is a diffraction grating type one comprising a plurality of light modulator elements, each light modulator element of said plurality of light modulator elements comprises fixed reflective portions having strip-like fixed reflective surfaces parallel to a base surface and moving ribbons having strip-like moving reflective surfaces parallel to said base surface, and said fixed reflective portions and said moving ribbons are alternately arranged in a predetermined direction in said each light modulator element,
• said moving ribbons are sagged in accordance with a voltage inputted to said each light modulator element, to change a height of said moving reflective surfaces from said base surface, said each light modulator element changes between a state of emitting a zeroth order light beam and a state of first order diffracted light beams, and a height of said moving reflective surfaces from said base surface is different from that of said fixed reflective surfaces from said base surface in a state where said moving ribbons are not sagged in said each light modulator element, and
• said image recording method comprises the steps of:
• a) setting a light amount of an output light, which is a zeroth order light beam or first order diffracted light beams outputted from said each light modulator element in an ON state, as a target ON light-amount which is common to said plurality of light modulator elements;
• b) obtaining a target ON-voltage which is equal to an input voltage to said each light modulator element when an output light-amount of said each light modulator element first reaches said target ON light-amount in gradually increasing or decreasing said input voltage from a voltage corresponding to the first maximum light-amount when a light amount of an output light first becomes maximum from when said moving ribbons start to sag in increasing said input voltage;
• and
• c) performing ON/OFF control of said each light modulator element while said target ON-voltage is inputted to said each light modulator element brought into an ON state and applying light to said spatial light modulator concurrently with said ON/OFF control, to apply light emitted from said spatial light modulator onto a recording material while moving said light relatively to said recording material.

An apparatus for correcting output light-amounts of a spatial light modulator with diffraction grating structure comprising a plurality of light modulator elements, wherein

• each light modulator element of said plurality of light modulator elements comprises fixed reflective portions having strip-like fixed reflective surfaces parallel to a base surface and moving ribbons having strip-like moving reflective surfaces parallel to said base surface, and said fixed reflective portions and said moving ribbons are alternately arranged in a predetermined direction in said each light modulator element,
• said moving ribbons are sagged in accordance with a voltage inputted to said each light modulator element, to change a height of said moving reflective surfaces from said base surface, said each light modulator element changes between a state of emitting a zeroth order light beam and a state of first order diffracted light beams, and a height of said moving reflective surfaces from said base surface is different from that of said fixed reflective surfaces from said base surface in a state where said moving ribbons are not sagged in said each light modulator element,
• said apparatus for correcting output light-amounts of a spatial light modulator comprises:
• a light source for applying light to a spatial light modulator;
• a control part for inputting a voltage to said each light modulator element;
• a light amount measurement part for measuring a light amount of an output light which is a zeroth order light beam or first order diffracted light beams outputted from said each light modulator element;
• and
• a target voltage obtaining part for obtaining a target voltage which is inputted to said each light modulator element when a light amount of an output light from said each light modulator element is made to a target light-amount, and
• said control part, said light amount measurement part, and said target voltage obtaining part execute the steps of:
• a) setting a light amount of an output light outputted from said each light modulator element in an ON state or an OFF state, as a target light-amount which is common to said plurality of light modulator elements;
• and
• b) obtaining a target voltage which is equal to an input voltage to said each light modulator element when an output light-amount of said each light modulator element first reaches said target light-amount in gradually increasing or decreasing said input voltage from a voltage corresponding to a light amount which is closer to said target light-amount out of the first minimum light-amount when a light amount of an output light first becomes minimum from when said moving ribbons start to sag in increasing said input voltage and the first maximum light-amount when a light amount of an output light first becomes maximum from when said moving ribbons start to sag in increasing said input voltage.

An image recording apparatus for recording an image on a recording material irradiated with light from a spatial light modulator while moving said light relatively to said recording material, comprising:

• a spatial light modulator;
• a light source for applying light to said spatial light modulator;
• a correction device for correcting output light-amounts outputted from said spatial light modulator;
• a signal processing part for generating an image signal inputted to said spatial light modulator;
• and
• a scanning mechanism for applying light emitted from said spatial light modulator onto a recording material while moving said light relatively to said recording material, wherein
• said spatial light modulator is a diffraction grating type one comprising a plurality of light modulator elements, each light modulator element of said plurality of light modulator elements comprises fixed reflective portions having strip-like fixed reflective surfaces parallel to a base surface and moving ribbons having strip-like moving reflective surfaces parallel to said base surface, and said fixed reflective portions and said moving ribbons are alternately arranged in a predetermined direction in said each light modulator element,
• said moving ribbons are sagged in accordance with a voltage inputted to said each light modulator element, to change a height of said moving reflective surfaces from said base surface, said each light modulator element changes between a state of emitting a zeroth order light beam and a state of first order diffracted light beams, and a height of said moving reflective surfaces from said base surface is different from that of said fixed reflective surfaces from said base surface in a state where said moving ribbons are not sagged in said each light modulator element,
• said correction device comprises:
• a control part for inputting a voltage to said each light modulator element;
• a light amount measurement part for measuring a light amount of an output light which is a zeroth order light beam or first order diffracted light beams outputted from said each light modulator element;
• and
• a target voltage obtaining part for obtaining a target voltage which is inputted to said each light modulator element when a light amount of an output light from said each light modulator element is made to a target light-amount, and
• said control part, said light amount measurement part, and said target voltage obtaining part execute the steps of:
• a) setting a light amount of an output light outputted from said each light modulator element in an ON state or an OFF state, as a target light-amount which is common to said plurality of light modulator elements;
• and
• b) obtaining a target voltage which is equal to an input voltage to said each light modulator element when an output light-amount of said each light modulator element first reaches said target light-amount in gradually increasing or decreasing said input voltage from a voltage corresponding to a light amount which is closer to said target light-amount out of the first minimum light-amount when a light amount of an output light first becomes minimum from when said moving ribbons start to sag in increasing said input voltage and the first maximum light-amount when a light amount of an output light first becomes maximum from when said moving ribbons start to sag in increasing said input voltage.