Barcode imaging workstation having sequentially activated object sensors

1. An apparatus comprising:

a housing having a first window in an upright plane and a second window in a generally horizontal plane that intersects the upright plane;

an imaging sensor within the housing and having an array of photosensitive elements;

a proximity system including multiple object sensors each associated with an object field of view for detecting a target object outside the housing, wherein each object sensor includes an infrared (IR) emitter for emitting IR light into an IR emission field and an IR sensor for sensing returned IR light within an IR detection field that intersects the IR emission field;

an illumination system supported by the housing and operative for illuminating the target object with illumination light;

a controller operatively connected to the imaging sensor, the illumination system and the proximity system, for energizing the illumination system in response to detection of the target object in one of the object field of view associated with the multiple object sensors and processing the illumination light returned from the target object and being captured in a field of view associated with the imaging sensor, and operative for activating each one of the multiple object sensors sequentially wherein activating an object sensor comprises activating the IR emitter in the activated object sensor and detecting returned IR light caused by the IR emitter with the IR sensor in the activated object sensor; and

a multiplexer receiving inputs from multiple IR sensors and configured to transmit a signal from the IR sensor in each one of the multiple object sensors sequentially to an output of the multiplexer while blocking signals from other IR sensors from transmitting to the output of the multiplexer.

2. The apparatus of claim 1 , wherein each IR emitter includes a light emitting diode (LED).

3. The apparatus of claim 1 , wherein each IR sensor includes a photodetector.

4. The apparatus of claim 1 , further comprising:

a driver control configured to activate each one of the multiple object sensors sequentially by driving the IR emitter in the activated object sensor with a current.

5. The apparatus of claim 1 , further comprising:

a filter receiving the signal from the output of the multiplexer.

6. An apparatus comprising:

a housing having a first window in an upright plane and a second window in a generally horizontal plane that intersects the upright plane;

an imaging sensor within the housing and having an array of photosensitive elements;

a proximity system including multiple object sensors each associated with an object field of view for detecting a target object outside the housing, wherein each object sensor includes an infrared (IR) emitter for emitting IR light into an IR emission field and an IR sensor for sensing returned IR light within an IR detection field that intersects the IR emission field;

an illumination system supported by the housing and operative for illuminating the target object with illumination light;

a controller operatively connected to the imaging sensor, the illumination system and the proximity system, for energizing the illumination system in response to detection of the target object in one of the object field of view associated with the multiple object sensors and processing the illumination light returned from the target object and being captured in a field of view associated with the imaging sensor, and operative for activating each one of the multiple object sensors sequentially wherein activating an object sensor comprises activating the IR emitter in the activated object sensor and detecting returned IR light caused by the IR emitter with the IR sensor in the activated object sensor;

a driver control configured to activate each one of the multiple object sensors sequentially by driving the IR emitter in the activated object sensor with a current; and

a multiplexer receiving inputs from multiple IR sensors and configured to transmit a signal from the IR sensor in the activated object sensor to an output of the multiplexer while blocking signals from other IR sensors from transmitting to the output of the multiplexer.

7. An apparatus comprising:

a housing having a first window in an upright plane and a second window in a generally horizontal plane that intersects the upright plane;

an imaging sensor within the housing and having an array of photosensitive elements;

a proximity system including multiple object sensors each associated with an object field of view for detecting a target object outside the housing, wherein each object sensor includes an infrared (IR) emitter for emitting IR light into an IR emission field and an IR sensor for sensing returned IR light within an IR detection field that intersects the IR emission field;

an illumination system supported by the housing and operative for illuminating the target object with illumination light;

a controller operatively connected to the imaging sensor, the illumination system and the proximity system, for energizing the illumination system in response to detection of the target object in one of the object field of view associated with the multiple object sensors and processing the illumination light returned from the target object and being captured in a field of view associated with the imaging sensor, and operative for activating each one of the multiple object sensors sequentially wherein activating an object sensor comprises activating the IR emitter in the activated object sensor and detecting returned IR light caused by the IR emitter with the IR sensor in the activated object sensor;

a driver control configured to activate each one of the multiple object sensors sequentially by driving the IR emitter in the activated object sensor with a current modulated at a predetermined frequency;

a multiplexer receiving inputs from multiple IR sensors;

a bandpass filter receiving signals from an output of the multiplexer, the bandpass filter having the pass band thereof covering the predetermined frequency of the modulation current; and

wherein the multiplexer is configured to transmit a signal from the IR sensor in the activated object sensor to the bandpass filter while blocking signals from other IR sensors from transmitting to the bandpass filter.

8. The apparatus of claim 7 , further comprising:

a control circuit configured to control the driver control and the multiplexer.

9. The apparatus of claim 7 , further comprising:

a control circuit configured to control the predetermined frequency of the modulation current and the pass band of the bandpass filter.

10. A method of decoding using an imaging scanner having a solid-state imager having an array of photosensitive elements, the method comprising:

detecting a target object outside a housing with a proximity system, the housing having a first window in an upright plane and a second window in a generally horizontal plane that intersects the upright plane, wherein the proximity system comprises multiple object sensors each associated with an object field of view, wherein each object sensor includes an infrared (IR) emitter for emitting IR light into an IR emission field and an IR sensor for sensing returned IR light within an IR detection field that intersects the IR emission field;

activating each one of the multiple object sensors sequentially wherein activating an object sensor comprises activating the IR emitter in the activated object sensor and detecting returned IR light caused by the IR emitter with the IR sensor in the activated object sensor;

energizing an illumination system in response to detection of the target object with one of the multiple object sensors for illuminating the target object;

capturing an image of the target object in memory by detecting light reflected from the target object with the solid-state imager; and

transmitting a signal from the IR sensor in each one of the multiple object sensors sequentially to an output of a multiplexer while blocking signals from other IR sensors from transmitting to the output of the multiplexer.

11. The method of claim 10 , wherein each IR emitter includes a light emitting diode (LED).

12. The method of claim 10 , wherein each IR sensor includes a photodetector.

13. The method of claim 10 , further comprising:

activating each one of the multiple object sensors sequentially by driving the IR emitter in the activated object sensor with a current.

14. The method of claim 10 , further comprising:

filtering the signal from the output of the multiplexer with a filter.

15. A method of decoding using an imaging scanner having a solid-state imager having an array of photosensitive elements, the method comprising:

detecting a target object outside a housing with a proximity system, the housing having a first window in an upright plane and a second window in a generally horizontal plane that intersects the upright plane, wherein the proximity system comprises multiple object sensors each associated with an object field of view, wherein each object sensor includes an infrared (IR) emitter for emitting IR light into an IR emission field and an IR sensor for sensing returned IR light within an IR detection field that intersects the IR emission field;

activating each one of the multiple object sensors sequentially wherein activating an object sensor comprises activating the IR emitter in the activated object sensor and detecting returned IR light caused by the IR emitter with the IR sensor in the activated object sensor;

energizing an illumination system in response to detection of the target object with one of the multiple object sensors for illuminating the target object;

capturing an image of the target object in memory by detecting light reflected from the target object with the solid-state imager;

activating each one of the multiple object sensors sequentially by driving the IR emitter in the activated object sensor with a current; and

transmitting a signal from the IR sensor in the activated object sensor to an output of a multiplexer while blocking signals from other IR sensors from transmitting to the output of the multiplexer.

16. A method of decoding using an imaging scanner having a solid-state imager having an array of photosensitive elements, the method comprising:

detecting a target object outside a housing with a proximity system, the housing having a first window in an upright plane and a second window in a generally horizontal plane that intersects the upright plane, wherein the proximity system comprises multiple object sensors each associated with an object field of view, wherein each object sensor includes an infrared (IR) emitter for emitting IR light into an IR emission field and an IR sensor for sensing returned IR light within an IR detection field that intersects the IR emission field;

activating each one of the multiple object sensors sequentially wherein activating an object sensor comprises activating the IR emitter in the activated object sensor and detecting returned IR light caused by the IR emitter with the IR sensor in the activated object sensor;

energizing an illumination system in response to detection of the target object with one of the multiple object sensors for illuminating the target object;

capturing an image of the target object in memory by detecting light reflected from the target object with the solid-state imager;

activating each one of the multiple object sensors sequentially by driving the IR emitter in the activated object sensor with a current modulated at a predetermined frequency; and

transmitting a signal from the IR sensor in the activated object sensor to a bandpass filter while blocking signals from other IR sensors from transmitting to the bandpass filter, the bandpass filter having the pass band thereof covering the predetermined frequency of the modulation current.

17. The method of claim 16 , wherein the object field of views of at least two object sensors are overlapping with each other.