Automatic exposure system for imaging-based bar code reader

A method of determining an integration time for imaging a target object utilizing an imaging system including a 2D pixel arrayg apparatus comprising the steps of

• a) determining a target distance from the imaging system to the target object;
• b) determining a gain-integration time product value utilizing an equation wherein the gain-integration time product value is a function of a predetermined target image brightness and the target distance;
• and
• c) determining the integration time by selecting a gain value and solving for integration time given the gain-integration time product value.

An imaging system for a bar code reader comprising:

• a) an imaging engine including a pixel array and a focusing lens to focus an image of the target object onto the pixel array;
• b) imaging and decoding circuitry for capturing an image of the target bar code and decoding an image of the target bar code within the captured image;
• and
• c) an automatic exposure system to determine an integration time for capturing an image of the target bar code, the automatic exposure system determining an integration time by:
• 1) determining a target distance from the imaging system to the target bar code;
• 2) determining a gain-integration time product value utilizing an equation wherein the gain-integration time product value is a function of a predetermined target image brightness value and the target distance;
• and
• 3) determining the integration time by selecting a gain value and solving for integration time given the gain-integration time product value.

An automatic exposure system for use in an automatic identification system including an imaging system including a pixel array, and a focusing lens to focus an image of the target object onto the pixel array, the automatic exposure system comprising circuitry for determining an integration time for capturing an image of the target object by:

• a) determining a target distance from the imaging system to the target bar code;
• b) determining a gain-integration time product value utilizing an equation wherein the gain-integration time product value is a function of a predetermined target image brightness value and the target distance;
• and
• c) determining the integration time by selecting a gain value and solving for integration time given the gain-integration time product value.