BEAM IRRADIATION APPARATUS

Abstract

An attachment lens is arranged in a stage subsequent to a scanning lens. After a laser beam is converged by the scanning lens, the laser beam is converted into a parallel beam by the attachment lens. When the scanning lens is displaced in a direction perpendicular to an optical axis of the laser beam, a traveling direction of the laser beam is bent by a predetermined angle immediately after the laser beam passes through the scanning lens. Then, the traveling direction of the laser beam is further bent by a predetermined angle in the same direction by the passage of the laser beam through the attachment lens. Accordingly, a final swing angle of the laser beam outgoing from an outgoing window is increased by a swing angle imparted by the attachment lens compared with the case where the attachment lens is not arranged. One of lens surfaces of the attachment lens is formed in a toroidal surface, which allows the laser beam to have a long outline in a vertical direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and novel features of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings in which:

FIG. 1 shows a configuration of a beam irradiation apparatus according to a first embodiment of the invention;

FIG. 2 shows a configuration of a lens actuator in the first embodiment;

FIGS. 3A and 3B show simulation results of behaviors in which an irradiation laser beam and a separated beam are swung respectively when a scanning lens 301 is displaced in one direction in the first embodiment;

FIG. 4 shows a structure of a PSD of the first embodiment;

FIGS. 5A and 5B show the structure and a voltage characteristic of the PSD in the first embodiment respectively;

FIG. 6 shows a relationship between a movement amount of a scanning lens and a scanning angle in the first embodiment;

FIGS. 7A and 7B show an intensity distribution of a laser beam when an irradiation laser beam in the first embodiment is displaced;

FIGS. 8A and 8B show the intensity distribution of the laser beam when the irradiation laser beam in the first embodiment is displaced;

FIG. 9 shows the intensity distribution of the laser beam when the irradiation laser beam in the first embodiment is displaced;

FIGS. 10A and 10B show the intensity distribution of the laser beam when the irradiation laser beam in a second embodiment is displaced;

FIGS. 11A and 11B show the intensity distribution of the laser beam when the irradiation laser beam in the second embodiment is displaced;

FIG. 12 shows the intensity distribution of the laser beam when the irradiation laser beam in the second embodiment is displaced;

FIGS. 13A and 13B show examples of a scanning orbit and a state of the irradiation laser beam in the second embodiment; and

FIG. 14 shows a configuration of a beam irradiation apparatus according to a modification.

Claims

1. A beam irradiation apparatus comprising: a light source which emits a laser beam;a scanning unit which displaces a traveling direction of the laser beam emitted from the light source toward a direction perpendicular to an optical axis of the laser beam; anda lens element which imparts wide angle action to a swing angle of the optical axis, the swing angle being generated by the scanning unit.

2. The beam irradiation apparatus according to claim 1, wherein the scanning unit displaces the laser beam in a first direction and a second direction, the first direction being perpendicular to the optical axis, and the second direction being perpendicular to both the first direction and the optical axis, andthe lens element imparts the wide angle action to the laser beam in at least one of the first direction and the second direction.

3. A beam irradiation apparatus comprising: a light source which emits a laser beam;a first lens which displaces a traveling direction of the laser beam emitted from the light source toward a direction perpendicular to an optical axis of the laser beam;an actuator which drives the first lens; anda second lens which imparts wide angle action to a swing angle of the optical axis, the swing angle being generated by displacing the first lens.

4. The beam irradiation apparatus according to claim 3, wherein the first lens converges the laser beam smaller than a parallel beam, andthe second lens diffuses the laser beam converged by the first lens into a substantially parallel state.

5. The beam irradiation apparatus according to claim 3, wherein the actuator two-dimensionally drives the first lens in a first direction and a second direction, the first direction being perpendicular to the optical axis of the laser beam, and the second direction being perpendicular to both the first direction and the optical axis, andthe second lens imparts the wide angle action to the laser beam in at least one of the first direction and the second direction.

6. The beam irradiation apparatus according to claims 3 or 4, wherein the second lens includes a first lens surface which imparts the wide angle action to the laser beam and a second lens surface which adjusts an outline of the laser beam.

7. The beam irradiation apparatus according to claim 6, wherein the second lens surface imparts optical action to the laser beam such that the outline of the laser beam becomes thin in one direction.

8. The beam irradiation apparatus according to any one of claims 3 to 5, further comprising: a beam dividing element which divides the laser beam passing through the first lens into a first light beam and a second light beam, the first light beam traveling toward the second lens, the second light beam traveling toward a direction different from the first light beam;a position sensor which receives the second light beam divided by the beam dividing element and outputs a signal according to an irradiation position of the laser beam passing through the second lens; anda third lens which is arranged between the position sensor and the beam dividing element to converge the second light beam onto the position sensor.

9. A beam irradiation apparatus comprising: a light source which emits a laser beam;a scanning unit which scans the laser beam emitted from the light source within a target region; andan optical member which deforms an outline of the laser beam in the target region so as to become thin in one direction.

10. The beam irradiation apparatus according to claim 9, wherein the scanning unit scans the laser beam in at least a horizontal direction within the target region, andthe optical member deforms the outline of the laser beam in the target region so as to become thin in a direction perpendicular to the horizontal direction.

11. The beam irradiation apparatus according to claim 9, wherein the scanning unit includes a first lens and an actuator, the laser beam being incident from the light source to the first lens, and the actuator driving the first lens in a direction perpendicular to an optical axis of the laser beam, andthe optical member includes a second lens which imparts focus action to the laser beam, a focal distance in the horizontal direction being different from a focal distance in the vertical direction in the focus action.

12. The beam irradiation apparatus according to claim 9, wherein the scanning unit includes a first lens and a polygon mirror, the laser beam being incident from the light source to the first lens, and the polygon mirror having a plurality of reflection planes which reflect the laser beam incident from the first lens, andthe optical member includes a second lens which imparts focus action to the laser beam, a focal distance in the horizontal direction being different from a focal distance in the vertical direction in the focus action.

13. The beam irradiation apparatus according to claims 11 or 12, wherein the second lens includes a first and a second passing surfaces through which the laser beam passes, and the first passing surface is formed in a lens surface which imparts the focus action to the laser beam, the focal distance in the horizontal direction being different from the focal distance in the vertical direction in the focus action.

14. The beam irradiation apparatus according to claim 13, wherein the lens surface is a toroidal surface in which the focal distance in the horizontal direction is different from the focal distance in the vertical direction.