1. A system, comprising:
a housing having a horizontal scanning window;
a laser scanning subsystem for projecting a laser scanning pattern through the horizontal scanning window and producing scan data for objects;
a scan data processor for processing the scan data produced by the laser scanning subsystem in an effort to read symbols on objects;
a weigh scale subsystem comprising a weigh platter above the horizontal scanning window, the weigh scale subsystem for weighing objects placed on the weigh platter and producing weigh data representative of the weight of objects weighed on the weigh platter; and
a weighing interference detection subsystem for projecting pairs of overlapping planar IR-based object detection planes normal to the weigh platter about the outer edges of the weigh platter to detect weighing interference conditions and generating control signals indicative of detected weighing interference conditions.
2. The system of claim 1, wherein the weighing interference conditions comprise detecting an object extending over the weigh platter’s spatial boundaries.
3. The system of claim 1, wherein the laser scanning pattern is an omni-directional laser scanning pattern.
4. The system of claim 1, wherein the weighing interference detection subsystem comprises object detection modules for projecting the pairs of overlapping planar IR-based object detection planes.
5. The system of claim 4, wherein each object detection module comprises a pair of optical devices for generating and projecting a pair of IR-based object sensing planes located.
6. The system of claim 1, wherein the weighing interference detection subsystem comprises a display device for indicating the detected weighing interference conditions.
7. A system, comprising:
a housing having a horizontal scanning window;
an imaging-based symbol reading subsystem for capturing images of objects on or above the horizontal scanning window and processing the captured images in an effort to read symbols on objects;
a weigh scale subsystem comprising a weigh platter above the horizontal scanning window, the weigh scale subsystem for weighing objects placed on the weigh platter and producing weigh data representative of the weight of objects weighed on the weigh platter; and
a weighing interference detection subsystem for projecting pairs of overlapping planar IR-based object detection planes normal to the weigh platter about the outer edges of the weigh platter to detect weighing interference conditions and generating control signals indicative of detected weighing interference conditions.
8. The system of claim 7, wherein the weighing interference conditions comprise detecting an object extending over the weigh platter’s spatial boundaries.
9. The system of claim 7, the weighing interference detection subsystem comprises object detection modules for projecting the pairs of overlapping planar IR-based object detection planes.
10. The system of claim 9, wherein each object detection module comprises:
an IR-based light source for generating and projecting a IR-based object sensing plane located; and
a photo-diode for detecting reflections of the IR-based object sensing plane off an object extending over the weigh platter’s spatial boundaries.
11. The system of claim 7, wherein the weighing interference detection subsystem comprises a display device for indicating the detected weighing interference conditions.
12. A method of weighing objects on a weigh platter having outer edges, comprising:
projecting pairs of overlapping planar IR-based object detection planes normal to the weigh platter about the outer edges of the weigh platter;
detecting, with the projected pairs of overlapping planar IR-based object detection planes, if one or more objects are extending over an outer edge of the weigh platter;
weighing an object on the weigh platter; and
if an object extending over an outer edge of the weigh platter is not detected, transmitting the weight of the object;
if an object extending over an outer edge of the weigh platter is detected, not transmitting the weight of the object.
13. The method of claim 12, comprising, in response to the detection of an object extending over an outer edge of the weigh platter, alerting a cashier.
14. The method of claim 12, comprising detecting reflections of the IR-based object detection planes from objects extending beyond the outer edges of said weigh platter.
15. The method of claim 12, comprising generating audible andor visual signals indicating the detection of an object extending over a spatial boundary of the weigh platter.
16. The method of claim 12, comprising scanning an object on the weigh platter with a plurality of laser scanning planes.
17. The method of claim 12, comprising scanning an object on the weigh platter with an omni-directional laser scanning pattern.
18. The method of claim 12, comprising capturing an image of an object on the weigh platter.
19. The method of claim 12, comprising detecting the presence of an operator in proximity to the weigh platter.
20. The method of claim 12, comprising:
capturing an image of an object on the weigh platter; and
processing the captured image in an effort to read symbols on the object.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A laser device comprising:
a light source comprising a semiconductor laser emitting a fundamental wave in a multi-longitudinal mode; and
a wavelength converting element comprising a polarization inversion element having at least two polarization inversion periodic regions, each region having a period \u0394 with respect to a longitudinal mode constructing the fundamental wave;
wherein a higher harmonic wave generated by the polarization inversion element is in a multi-longitudinal mode.
2. The laser device according to claim 1, wherein the polarization inversion element includes differences between the periods \u0394 of the periodic regions being set constant
3. The laser device according to claim 2, wherein the polarization inversion element includes respective differences between the periods \u0394 of the periodic regions being set to from 0.01 to 0.8 \u03bcm.
4. The laser device according to claim 3, wherein the polarization inversion element has the period \u0394 in a range between about 3.1 and about 3.5 \u03bcm.
5. The laser device according to claim 4, wherein the semiconductor laser emits a fundamental wave of in a multi-longitudinal mode having a main emission wavelength between about 1000 nm and about 1200 nm.
6. The laser device according to claim 5, wherein the semiconductor laser has an active layer represented by a formula InxGa1-x-yNzAsyP1-y, where 0.1<x<0.84, 0.25<y<0.5, and z=0 or 1.
7. The laser device according to claim 6, wherein the semiconductor laser, as a fundamental wave-emitting device, comprises a substrate made of InP.
8. The laser device according to claim 7, wherein the polarization inversion element is made of a single crystal of lithium niobate (LiNbO3), lithium tantalate (LiTaO3), lithium niobate-lithium tantalate solid solution, potassium titanyl phosphate (KTiOPO4) or potassium lithium niobate (K3Li2Nb5O15).
9. The laser device according to claim 8, further comprising a coolingheating element which is in contact with the polarization inversion element.
10. A laser device comprising:
a light source comprising a semiconductor laser emitting a fundamental wave in a multi-longitudinal mode; and
a wavelength converting element comprising a polarization inversion element having at least two polarization inversion periodic regions, each region having a period \u0394 with respect to a longitudinal mode constructing the fundamental wave;
wherein at least one periodic region is adjusted to match a plurality of longitudinal modes of the fundamental wave, and a higher harmonic wave generated by the polarization inversion element is in a multi-longitudinal mode.
11. The laser device according to claim 10, wherein the periodic region corresponding to the plurality of longitudinal modes is periodically chirped.
12. The laser device according to claim 11, wherein the polarization inversion element has a periodic region corresponding to the plurality of longitudinal modes, and a periodic region corresponding to at least one of the plurality of longitudinal modes and having a mean period different than a mean period of the periodic region corresponding to the plurality of longitudinal modes.
13. The laser device according to claim 12, wherein in the polarization inversion element, differences of the mean periods between the periodic regions is set minimum between most adjacent periodic regions.
14. The laser device according to claim 13, wherein in the polarization inversion element, differences of the mean periods between the periodic regions are set constant.
15. The laser device according to claim 13, wherein respective higher harmonic waves converted in periodic regions corresponding to the plurality of longitudinal modes and having different mean periods overlap each other.
16. A laser device comprising:
a light source comprising a semiconductor laser emitting a fundamental wave in a multi-longitudinal mode; and
a wavelength converting element comprising a polarization inversion element having at least two polarization inversion periodic regions, each region having a period \u0394 with respect to a longitudinal mode constructing the fundamental wave;
wherein at least one longitudinal mode of the fundamental wave as a common longitudinal mode, a wavelength of the common longitudinal mode can be converted in a plurality of periodic regions having different mean periods, and a higher harmonic wave generated by the polarization inversion element is in a multi-longitudinal mode.
17. The laser device according to claim 16, wherein the higher harmonic wave also corresponds to a longitudinal mode different than the common longitudinal mode in the plurality of periodic regions having different mean periods each other.
18. The laser device according to claim 17, wherein the polarization inversion element includes differences between the mean periods of the periodic regions being set to from 0.01 to 0.08 \u03bcm.
19. The laser device according to claim 18, wherein the polarization inversion element includes differences between the mean periods being set constant.
20. A method for manufacturing a laser device, comprising:
providing a light source that emits a fundamental wave in a multi-longitudinal mode; and
providing a wavelength converting element to convert light from the light source, and the wavelength converting element is a polarization inversion element having at least two polarization inversion periodic regions, each region having a period \u0394 with respect to a longitudinal mode constructing the fundamental wave, and the polarization inversion element generates a higher harmonic wave in a multi-longitudinal mode.