Portable data collection device with LED targeting and illumination assembly

• US 5,783,811 A
• Filed: 02/26/1996
• Issued: 07/21/1998
• Est. Priority Date: 06/26/1995
• Status: Expired due to Term

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Metanetics Corporation
• Inventors: Feng, Chen, Wang, Ynjiun P.
• Primary Examiner(s): Hajec, Donald T.
• Assistant Examiner(s): Le, Thien Minh
• Application Number:
  US08/606,619
• Time in Patent Office: 876 Days
• Field of Search: 235/462, 235/472, 235/459, 235/454, 235/467, 235/463
• US Class Current: 235/462.42
• CPC Class Codes: G01J 3/0272 Handheld
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01J 3/51 using colour filters
• CPC Class Codes: G01J 3/513 having fixed filter-detector pairs
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G06K 2207/1011 Aiming
• CPC Class Codes: G06K 7/10564 Light sources
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10752 Exposure time control
• CPC Class Codes: G06K 7/10792 Special measures in relation to the object to be scanned

Abstract

The device includes an imaging assembly including a two dimensional (2D) photosensor array overlied by a RGB color filter. The imaging assembly includes an illumination assembly providing a relatively uniform illumination pattern over an imaging target area. The illumination assembly includes a plurality of sets of surface mount illumination LEDs mounted on a board and a spaced apart lens array for focusing the LEDs on the target area. The lens array includes orthogonal cylindrical optical entry and exit surfaces aligned with each of the illumination LED sets. The optical entry surface defines illumination intensity distribution horizontally while the optical exit surface defines illumination intensity distribution vertically. The board also supports a pair of spaced apart targeting LEDs. The lens array includes aspherical optical entry surfaces and cylindrical optical exit surfaces aligned with each of the targeting LEDs. The cylindrical optical exit surfaces are tipped with respect to their corresponding aspherical optical entry surfaces and are orthognal to each other providing an orgthogonal or "crosshairs" illumination pattern for aiming the imaging assembly at a target.

Claims

1. A portable data collection device, comprising:

a) a camera assembly, including an array of photosensor elements generating a signal representative of an image of a generally rectangular target area of the device,

b) an optics assembly positioned to focus illumination reflected from the generally rectangular target area onto said photosensor elements, the target area having a height and a width,

c) image processing and decoder circuitry receiving said signal and generating decoded data representative of the dataform, and

d) an illumination assembly directing illumination towards the target area, the illumination assembly including a lens array with a cylindrical optic entry surface with an entry longitudinal axis and a cylindrical optic exit surface with an exit longitudinal axis, the entry longitudinal axis being orientated substantially orthogonal to the exit longitudinal axis.

2. The device of claim 1 wherein at least one of the cylindrical optic entry surface and the cylindrical optic exit surface defines an illumination intensity distribution that is substantially even across the width of the target area.

3. The device of claim 2 wherein the other of the entry surface and the exit surface defines an illumination intensity distribution that is substantially even across the height of the target area.

4. The device of claim 3 wherein the entry longitudinal axis is substantially aligned along the height dimension of the target area and defines the illumination intensity distribution over the width of the target area, and wherein the exit longitudinal axis is substantially aligned along the width dimension of the target area and defines the illumination intensity distribution over the height of the target area.

5. The device of claim 3 wherein the illumination assembly includes a plurality of cylindrical optic entry surfaces and a common cylindrical optic exit surface optically associated with the plurality of entry surfaces, and a plurality of light emitting diodes, each diode positioned to project illumination through a selected one of the optic entry surfaces and the common optic exit surface.

6. The device of claim 5 wherein the illumination assembly includes sixteen cylindrical optic entry surfaces positioned in four rows of four surfaces each with four common cylindrical optic exit surfaces, each exit surface extending across one of the four rows, and sixteen light emitting diodes, each positioned to project illumination through a selected on of the entry surfaces and the associated common exit surface.

7. The device of claim 1, wherein the illumination assembly includes a plurality of surface mount LEDs mounted on a board and illumination through the lens array towards the target area.

8. A portable data collection device comprising:

a) a camera assembly, including an array of photosensor elements generating a signal representative of an image of a target area,

b) an optics assembly positioned to focus illumination reflected from a generally rectangular target area onto said photosensor elements, the target area having a height and a width,

c) image processing and decoder circuitry receiving said signal and generating decoded data representative of the dataform, and

d) an illumination assembly directing illumination towards the target area, the illumination assembly including a targeting arrangement for directing an illumination intensity distribution resembling a cross hair pattern toward the target area to aid in aiming the portable data collection device, the crosshair pattern being stationary with respect to the target area.

9. A portable data collection device comprising:

a) a camera assembly, including an array of photosensor elements generating a signal representative of an image of a generally rectangular target area of the assembly,

b) an optics assembly positioned to focus illumination reflected from the generally rectangular target area onto said photosensor elements, the target area having a height and a width,

c) image processing and decoder circuitry receiving said signal and generating decoded data representative of the dataform, and

d) an illumination assembly directing illumination towards the target area, the illumination assembly including a targeting arrangement for directing an illumination intensity distribution resembling a cross hair pattern to aid in aiming the portable data collection device, the cross hair pattern including a horizontal line with a width substantially corresponding to the width of the target area and a vertical line with a height substantially corresponding to the height of the target area.

10. The device of claim 9, wherein the targeting arrangement includes a horizontal line illumination generating arrangement including a lens element with an optic entry surface and a cylindrical optic exit surface, the entry surface and the exit surface defining a thin horizontal illumination intensity distribution pattern extending approximately the width of the target area.

11. The device of claim 10, wherein the horizontal line illumination generating arrangement is positioned to the side of the camera assembly and the exit surface is tipped with respect to the entry surface such that the horizontal illumination intensity distribution pattern is approximately centered within the field of view of the camera assembly.

12. The device of claim 10, wherein the targeting arrangement further includes a vertical line illumination generating arrangement including a lens element with an optic entry surface and a cylindrical, optic exit surface, the entry surface and the exit surface defining a thin vertical illumination intensity distribution pattern extending approximately the height of the target area.

13. The device of claim 12, wherein the horizontal line illumination generating arrangement is positioned to one side of the camera assembly and the vertical line illumination generating arrangement is positioned to an opposite side of the camera assembly and the horizontal line illumination generating exit surface is tipped with respect to the entry surface such that the horizontal illumination intensity distribution pattern is approximately centered within the field of view of the camera assembly and the vertical line illumination generating exit surface is tipped with respect to the entry surface such that the vertical illumination intensity distribution pattern is approximately centered within the field of view of the camera assembly.

14. The device of claims 10, 11, 12, or 13 wherein at least one of the horizontal line illumination generating arrangement entry surface and the vertical line illumination generating arrangement entry surface is an aspherical surface.

15. A portable data collection device for reading a dataform positioned in a target area of the device, the device comprising:

a) a housing forming an interior region,

b) an imaging assembly at least partially enclosed in the interior region, for capturing an image of the dataform and providing decoded data representative of the dataform in the target area,

c) a user activated actuator at least partially exposed on the exterior of the housing for actuating the imaging assembly to read a dataform, and

d) the imaging assembly including a modular housing supporting a camera assembly with a field of view corresponding to the target area and further supporting an illumination assembly directing exposure illumination towards the target area, the illumination assembly including targeting optics for directing targeting illumination towards the target area for aiding in aiming the device at the dataform, the targeting illumination includes at least one thin illumination intensity distribution pattern that is stationary with respect to the target area of the device and extends between two sides of the target area.

16. A portable data collection device for reading a dataform positioned in a target area of the device, the device comprising:

a) a housing forming an interior region,

b) an imaging assembly at least partially enclosed in the interior region, for capturing an image of the dataform and providing decoded data representative of the dataform in the target area,

c) a user activated actuator at least partially exposed on the exterior of the housing for actuating the imaging assembly to read a dataform, and

d) the imaging assembly including a modular housing supporting a camera assembly with a field of view corresponding to the target area and further supporting an illumination assembly directing exposure illumination towards the target area and targeting illumination towards the target area for aiding in aiming the device, the modular housing having a camera support surface for positioning the camera assembly with respect to the housing and an illumination assembly support surface for positioning the illumination assembly at a fixed position with respect to the camera such that a field of illumination substantially coincides with the field of view of the camera assembly.

17. The device of claim 16 wherein the illumination assembly includes a targeting illumination arrangement generating a targeting illumination intensity distribution pattern forming a cross hair pattern centered within the field of view of the camera assembly.

18. The device of claim 17 wherein the illumination assembly includes a targeting illumination arrangement and further wherein the targeting illumination arrangement includes a horizontal line illumination generating arrangement, including an illumination source and an optic, each supported by the modular housing and generating a thin horizontal illumination intensity distribution pattern substantially centered within the field of view of the camera assembly, and the targeting illumination arrangement further including a vertical line illumination generating arrangement, including an illumination source and an optic, each supported by the modular housing and generating a thin vertical illumination intensity distribution pattern centered within the field of view of the camera assembly.

19. The device of claim 18, wherein the horizontal illumination intensity distribution pattern and the vertical illumination intensity distribution pattern extend approximately the width and the height of the target area respectively.

20. The device of claim 18 wherein the horizontal line illumination generating optic includes an aspheric optic entry surface and a cylindrical optic exit surface with a substantially vertical longitudinal axis and the vertical line illumination generating optic includes an aspheric optic entry surface and a cylindrical optic exit surface with a substantially horizontal longitudinal axis.