Graphical code reader having illumination LEDs of different wavelengths

A graphical code reader, comprising:

• an infrared light-emitting diode;
• a red light-emitting diode;
• an image sensor;
• a lens positioned to focus reflected light on the image sensor;
• a processor;
• memory in electronic communication with the processor;
• and
• instructions stored in the memory, the instructions being executable by the processor to implement a method comprising:
• illuminating the infrared light-emitting diode at an infrared illumination intensity level;
• illuminating the red light-emitting diode at a red illumination intensity level;
• capturing a digital image for processing, the digital image being an electronic representation of an optical image formed on the image sensor;
• and
• processing the digital image to attempt to decode a graphical code within the digital image, wherein the method further comprises;
• determining a brightness of the digital image;
• determining a desired brightness of the digital image;
• determining a difference signal which indicates a difference between the brightness of the image and the desired brightness of the digital image;
• adjusting the infrared illumination intensity level in proportion to the difference signal;
• and
• adjusting the red illumination intensity level in proportion to the difference signal.

A graphical code reader, comprising:

• an infrared light-emitting diode;
• a red light-emitting diode;
• a near field that includes a near-field image sensor region and a near-field lens positioned to focus first reflected light on the near-field image sensor region;
• a far field that includes a far-field image sensor region and a far-field lens positioned to focus second reflected light on the far-field image sensor region, and wherein a first distance between the near-field lens and the near-field image sensor region is greater than a second distance between the far-field lens and the far-field image sensor region;
• a processor;
• memory in electronic communication with the processor;
• and
• instructions stored in the memory, the instructions being executable by the processor to implement a method comprising:
• illuminating the infrared light-emitting diode at an infrared illumination intensity level;
• illuminating the red light-emitting diode at a red illumination intensity level;
• obtaining a digital image, the digital image being an electronic representation of an optical image formed on at least one of the near-field image sensor region and the far-field image sensor region;
• and
• processing the digital image to attempt to decode a graphical code within the digital image.

In a graphical code reader, a method comprising:

• illuminating an infrared light-emitting diode at an infrared illumination intensity level;
• illuminating a red light-emitting diode at a red illumination intensity level;
• capturing a digital image for processing, the digital image being an electronic representation of an optical image formed on an image sensor;
• and
• processing the digital image to attempt to decode a graphical code within the digital image, wherein the graphical code reader is configured such that the user can set the infrared illumination intensity level and the red illumination intensity level.

In a graphical code reader, a method comprising:

• illuminating an infrared light-emitting diode at an infrared illumination intensity level;
• illuminating a red light-emitting diode at a red illumination intensity level;
• capturing a digital image for processing, the digital image being an electronic representation of an optical image formed on an image sensor;
• processing the digital image to attempt to decode a graphical code within the digital image;
• determining a brightness of the digital image;
• determining a desired brightness of the digital image;
• determining a difference signal which indicates a difference between the brightness of the image and the desired brightness of the digital image;
• adjusting the infrared illumination intensity level in proportion to the difference signal;
• and
• adjusting the red illumination intensity level in proportion to the difference signal.

In a graphical code reader comprising a near field and a far field, the near field including a near-field image sensor region and a near-field lens positioned to focus first reflected light on the near-field image sensor region, and the far field including a far-field image sensor region and a far-field lens positioned to focus second reflected light on the far-field image sensor region, a method comprising:

• illuminating an infrared light-emitting diode at an infrared illumination intensity level;
• illuminating a red light-emitting diode at a red illumination intensity level;
• obtaining a digital image, the digital image being an electronic representation of an optical image formed on at least one of the near-field image sensor region and the far-field image sensor region;
• and
• processing the digital image to attempt to decode a graphical code within the digital image, wherein a first distance between the near-field lens and the near-field image sensor region is greater than a second distance between the far-field lens and the far-field image sensor region.