Compact autofocus bar code reader with moving mirror

1. An imaging based barcode reader for imaging a target comprising:

an imaging system that includes a light monitoring pixel array,

a focusing lens fixed with respect to the pixel array to transmit an image of a target object to the pixel array;

a mirror mounted for movement along a path of travel to reflect light passing through the lens onto the pixel array;

a drive for moving the mirror relative the lens to adjust a focus of an image of the target object formed at the pixel array;

an aiming pattern generator that emits an aiming pattern to impinge upon and illuminate a portion of the target object; and

an automatic focusing component for analyzing the aiming pattern reflected from the target object and projected onto the pixel array by the lens and moving the mirror along its path of travel to a suitable position for properly focusing the target object onto the pixel array; and

wherein the automatic focusing component comprises means for identifying a position of the aiming pattern on the pixel array and activating the drive to move the mirror until the position of the aiming pattern on the pixel array is moved to a predetermined position.

2. The reader of claim 1 wherein the mirror is angled with respect to the pixel array at approximately a forty five degree angle.

3. The reader of claim 1 wherein the mirror moves along a generally linear travel path.

4. The reader of claim 1 additionally comprising a handheld housing that can be manipulated by a user to position the aiming pattern with respect to indicia on the target.

5. The reader of claim 1 wherein the automatic focusing component comprises:

a motor drive for moving the mirror and a position encoder for determining a position of the mirror with respect to the lens as the motor drive moves the mirror.

6. The reader of claim 1 wherein the automatic focusing component comprises means for identifying a position of the aiming pattern on the pixel array and activating the drive to move the mirror until the position of the aiming pattern on the pixel array is centered on an optical axis of the lens.

7. A method of focusing an image of a target object on an imaging system of an automatic identification system including an imaging pixel array comprising:

orienting a focusing lens to transmit light from the target object;

reflecting light passing through the focusing lens from the target object onto the imaging pixel array by positioning a mirror to intercept light passing through the focusing lens and redirecting said light to the imaging pixel array;

forming an aiming pattern at a plane of a target object and;

adjusting a focus of the reader for the target object imaging by moving the mirror to adjust a light path distance between the imaging pixel array and the focusing lens; and

wherein the focus of the aiming pattern is adjusted until an image of the aiming pattern on the imaging pixel array is moved to a predetermined position.

8. The method of claim 7 wherein the image of the aiming pattern is moved to a position centered along the optical axis of the lens as bent by the mirror.

9. The method of claim 7 wherein the focus is adjusted by moving the mirror along the path of travel to a suitable position for properly focusing the target object onto the pixel array.

10. The method of claim 7 wherein multiple images of the target object are formed based on multiple mirror positions and comparing a focus of the multiple images to determine a best mirror position.

11. The method focusing an image of claim 7 additionally comprising collecting data indicative of an image reflected back from an illuminated portion of the target object and decoding indicia on the target object based on the collected data from the portion of the indicia that is illuminated.

12. An imaging based barcode reader for imaging a target object comprising:

imaging means for forming an image on a light monitoring pixel array,

focusing means fixed with respect to the pixel array for transmitting an image of a target object to the pixel array;

reflection means mounted for movement along a path of travel for reflecting light subsequent to the focusing means onto the pixel array;

drive means for moving the reflection means and adjusting a focus of an image of the target object formed at the pixel array;

means for generating an aiming pattern that emits an aiming pattern to impinge upon and illuminate a portion of a coded indicia;

automatic focusing means for analyzing the aiming pattern reflected from the target object and projected onto the pixel array and moving the reflection means along its path of travel to a suitable position for properly focusing the target object onto the pixel array; and

the automatic focusing means comprises means for identifying a position of the aiming pattern on the pixel array and activating the drive to move the mirror until the position of the aiming pattern on the pixel array is is moved to a predetermined position.

13. The reader of claim 12 wherein the automatic focusing means comprises means for identifying a position of the aiming pattern on the pixel array and activating the drive to move the mirror until the position of the aiming pattern on the pixel array is centered on an optical axis of the focusing means.