Variable focal position spatial modulation device

A variable focal position spatial modulation device comprising:

• a variable refractive index material that is arranged inside a luminous flux and that is able to deflect an incident light;
• a plurality of electrode pairs arranged at intervals in one of a concentric shape, a concentric oval shape and an unequally magnified concentric oval shape, in which a pair of electrodes of each of the electrode pairs are generally opposite to each other with interposition of the variable refractive index material between the pair of electrodes;
• and
• a voltage supplier for supplying a voltage across the electrodes, in which a refractive index distribution of the variable refractive index material changes in accordance with the voltage supplied across the electrodes, so that a focal position is changed, wherein the electrode pairs have the width thereof on one of sides of the variable refractive index material different from the width thereof on the other of sides of the variable refractive index material.

A variable focal position spatial modulation device comprising:

• a variable refractive index material that is arranged inside a luminous flux and that is able to deflect an incident light;
• a plurality of electrode pairs arranged at intervals in one of a concentric shape, a concentric oval shape and an unequally magnified concentric oval shape, in which a pair of electrodes of each of the electrode pairs are generally opposite to each other with interposition of the variable refractive index material between the pair of electrodes;
• and
• a voltage supplier for supplying a voltage across the electrodes, in which a refractive index distribution of the variable refractive index material changes in accordance with the voltage supplied across the electrodes, so that a focal position is changed,
• wherein the variable refractive index material is partitioned into a first region including both a first field in which the pair of electrodes of a first electrode pair of the electrode pairs oppose each other and a second field around the first field, and into a second region, adjacent to the first region, including both a third field in which the pair of electrodes of a second electrode pair of the electrode pairs oppose each other and a fourth field around the third field, and
• wherein there is provided an electric field shield that is arranged between the first region and the second region, thereby reducing the mutual influence of electric fields of the first and second regions exerting on each other.

A variable focal position spatial modulation device comprising:

• a variable refractive index material that is arranged inside a luminous flux and that is able to deflect an incident light;
• a plurality of electrode pairs arranged at intervals in one of a concentric shape, a concentric oval shape and an unequally magnified concentric oval shape, in which a pair of electrodes of each of the electrode pairs are generally opposite to each other with interposition of the variable refractive index material between the pair of electrodes;
• a voltage supplier for supplying a voltage across the electrodes, in which a refractive index distribution of the variable refractive index material changes in accordance with the voltage supplied across the electrodes, so that a focal position is changed;
• and
• an electric field reducing electrode that is provided adjacently to at least one of the pair of electrodes of the each of the electrode pairs and reduces the electric field formed by the at least one thereof,
• wherein the variable refractive index material is partitioned into a first region including both a first field in which the pair of electrodes of a first electrode pair of the electrode pairs oppose each other and a second field around the first field, and into a second region, adjacent to the first region, including both a third field in which the pair of electrodes of a second electrode pair of the electrode pairs oppose each other and a fourth field around the third field.

A variable focal position spatial modulation device comprising:

• a variable refractive index material that is arranged inside a luminous flux and that is able to deflect an incident light;
• a plurality of electrode pairs arranged at intervals in one of a concentric shape, a concentric oval shape and an unequally magnified concentric oval shape, in which a pair of electrodes of each of the electrode pairs are generally opposite to each other with interposition of the variable refractive index material between the pair of electrodes;
• a voltage supplier for supplying a voltage across the electrodes, in which a refractive index distribution of the variable refractive index material changes in accordance with the voltage supplied across the electrodes, so that a focal position is changed;
• and
• a light shielding mask for shielding the luminous flux which passes through a portion of the variable refractive index material, in which the portion is other than a portion having a desired refractive index distribution.

A variable focal position spatial modulation device comprising:

• a variable refractive index material that is arranged inside a luminous flux and that is able to deflect an incident light;
• a plurality of electrode pairs arranged at intervals in one of a concentric shape, a concentric oval shape and an unequally magnified concentric oval shape, in which a pair of electrodes of each of the electrode pairs are generally opposite to each other with interposition of the variable refractive index material between the pair of electrodes;
• and
• a voltage supplier for supplying a voltage across the electrodes, in which a refractive index distribution of the variable refractive index material changes in accordance with the voltage supplied across the electrodes, so that a focal position is changed, wherein interval between the electrode pairs adjacent to each other varies, depending upon a distance relative to a center of the device.

A variable focal position spatial modulation device comprising:

• a variable refractive index material that is arranged inside a luminous flux and that is able to deflect an incident light;
• a plurality of electrode pairs arranged at intervals in one of a concentric shape, a concentric oval shape and an unequally magnified concentric oval shape, in which a pair of electrodes of each of the electrode pairs are generally opposite to each other with interposition of the variable refractive index material between the pair of electrodes;
• and
• a voltage supplier for supplying a voltage across the electrodes, in which a refractive index distribution of the variable refractive index material changes in accordance with the voltage supplied across the electrodes, so that a focal position is changed, wherein the voltage supplier supplies different voltages to the electrode pairs, depending on locations of the electrode pairs relative to a center of the device.