DEVICE AND METHOD FOR OPERATING CAMERAS AND LIGHT SOURCES

• US 20180315865A1
• Filed: 05/01/2017
• Published: 11/01/2018
• Est. Priority Date: 05/01/2017
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Inventors: Haist, Paul D., Obotnine, Alexandre
• Granted Patent: US 10,505,057 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10752 Exposure time control
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 31/0232 Optical elements or arrangements associated with the device H01L31/0236 takes precedence; for photovoltaic cells H01L31/054; for photovoltaic modules H02S40/20
• CPC Class Codes: H01L 31/02327 the optical elements being integrated or being directly associated to the device, e.g. back reflectors optical coatings H01L31/0216
• CPC Class Codes: H01L 31/054 Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/661 Transmitting camera control signals through networks, e.g. control via the Internet
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means
• CPC Class Codes: H04N 23/81 for suppressing or minimising disturbance in the image signal generation
• CPC Class Codes: H04N 23/90 Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums
• CPC Class Codes: Y02E 10/52 PV systems with concentrators

Abstract

Provided herein is a device and method for improved operating of cameras and light sources of a mobile automation apparatus. Light sources are operated to periodically provide illumination light for a camera operating according to a given exposure time and frequency, with a pulse duration having a respective frequency that is an integer multiple of the camera frequency, and higher than a threshold frequency where successive activations of the light sources are imperceptible. Furthermore, a light source paired with a camera is located at a distance from the paired camera that illuminates an object imaged by the paired camera, and where parasitic reflections from the paired light source are not reflected into the paired camera.

Claims

1. A device comprising:

a camera, configured to acquire images periodically according to a given exposure time, and at a first given frequency; and

at least one light source configured to periodically provide illumination light for the camera, the illumination light having a pulse duration that corresponds to the given exposure time and having a second given frequency that is an integer multiple of the first given frequency, wherein the second given frequency is higher than a threshold frequency where successive activations of the at least one light source are imperceptible.

2. The device of claim 1, wherein each of the given exposure time and the pulse duration are about 0.5 ms.

3. The device of claim 1, wherein the first given frequency is about 5 Hz and the second given frequency is about 100 Hz.

4. The device of claim 1, wherein the threshold frequency is greater than 70 Hz.

5. The device of claim 1, wherein the at least one light source comprises at least one light emitting diode.

6. The device of claim 1, wherein the second given frequency is higher than the threshold frequency where the successive activations of the at least one light source are imperceptible to a human vision system.

7. The device of claim 1, wherein the at least one light source and the camera are powered by a battery.

8. The device of claim 1, wherein the given exposure time is selected such that the images acquired by the camera are not blurry when the device is moving at a given speed.

9. A method comprising:

at a device comprising a controller, a camera and at least one light source, controlling, using the controller, the camera to acquire images periodically according to a given exposure time, and at a first given frequency; and

controlling, using the controller, the at least one light source to periodically provide illumination light for the camera, the illumination light having a pulse duration that corresponds to the given exposure time and having a second given frequency that is an integer multiple of the first given frequency, wherein the second given frequency is higher than a threshold frequency where successive activations of the at least one light source are imperceptible.

10. The method of claim 9, wherein the second given frequency is higher than the threshold frequency where the successive activations of the at least one light source are imperceptible to a human vision system.

11. A device comprising:

a support structure;

a plurality of cameras spaced along the support structure, wherein adjacent cameras have partially overlapping fields of view directed away from the support structure; and

,

a plurality of light sources comprising at least one light source paired with each of the plurality of cameras,

wherein a paired light source is located at a distance from a paired camera that illuminates an object imaged by the paired camera, and where parasitic reflections from the paired light source are not reflected into the paired camera, and

wherein the paired light source and the paired camera are operated at a different time from other paired light sources and other paired cameras located where the parasitic reflections from the paired light source are reflected into the other paired cameras.

12. The device of claim 11, wherein the paired light source and the paired camera are operated at a same time as associated paired light sources and associated paired cameras, the paired camera and the associated paired cameras each located where respective parasitic reflections from the paired light source and the associated paired light sources are not reflected into the paired camera and the associated paired cameras.

13. The device of claim 11, wherein the plurality of cameras is operated in a sequence with associated paired light sources.

14. The device of claim 11, further comprising a mobile automation apparatus, the support structure disposed on the mobile automation apparatus, the plurality of cameras and the plurality of light sources spaced along the support structure.

15. The device of claim 11, further comprising a mobile automation apparatus, the support structure comprising a mast disposed on the mobile automation apparatus, the plurality of cameras and the plurality of light sources vertically spaced along the mast.

16. The device of claim 11, wherein at least one camera is located between the paired light source and the paired camera along the support structure.

17. The device of claim 11, wherein each of the plurality of light sources is pitched, with respect to the support structure, in a direction of an associated paired camera.

18. The device of claim 11, wherein a given camera, of the plurality of cameras is paired with at least a first subset of the plurality of light sources located on one side of the given camera, and a second subset of the plurality of light sources located on an opposite side of the given camera.

19. The device of claim 11, wherein associated subsets of the plurality of light sources are located in rows along the support structure, perpendicular to a line between the plurality of cameras, and wherein at least some of the rows are operated at a same time to provide illumination light for at least two of the plurality of cameras.

20. A method comprising:

at device comprising;

a controller;

a support structure;

a plurality of cameras spaced along the support structure, wherein adjacent cameras have partially overlapping fields of view directed away from the support structure; and

, a plurality of light sources comprising at least one light source paired with each of the plurality of cameras, wherein a paired light source is located at a distance from a paired camera that illuminates an object imaged by the paired camera, and where parasitic reflections from the paired light source are not reflected into the paired camera,

controlling, using the controller, the paired light source and the paired camera to operate at a different time from other paired light sources and other paired cameras located where the parasitic reflections from the paired light source are reflected into the other paired cameras; and

controlling, using the controller, the paired light source and the paired camera to operate at a same time as associated paired light sources and associated paired cameras, the paired camera and the associated paired cameras each located where respective parasitic reflections from the paired light source and the associated paired light sources are not reflected into the paired camera and the associated paired cameras.