Large depth of field navigation input devices and methods
View Patent ↗Disclosed are various embodiments of a navigation input device, and methods, systems and components corresponding thereto. According to some embodiments, the navigation input device has a large depth of field associated therewith and employs time- and/or frequency-domain processing algorithms and techniques. The device is capable of providing accurate and reliable information regarding the (X,Y) position of the device on a navigation surface as it is moved laterally thereatop and thereacross, notwithstanding changes in a vertical position of the device that occur during navigation and that do not exceed the depth of field of an imaging lens incorporated therein. According to one embodiment, the navigation input device is a writing instrument that does not require the use of an underlying touch screen, touch pad or active backplane to accurately and reliably record successive (X,Y) positions of the writing device as it is moved across and atop an underlying writing medium.
1. A navigation input device, comprising:
(a) a light source configured to project an illumination light downwardly therefrom;
(b) an aperture located beneath an illumination lens and configured to permit at least a portion of the illumination light to pass therethrough for incidence upon a navigation surface located below the aperture, wherein a diameter of the aperture ranges between about 0.25 mm and about 4 mm;
(d) an imaging lens having a depth of field of about 12 mm, about 14 mm, about 16 mm, about 18 mm, or about 20 mm and a focal length ranging between about 6 mm and about 50 mm, the imaging lens being at least one of achromatic, telecentric, or double telecentric and being positioned and configured to receive at least a portion of upwardly reflected light formed by at least a portion of the illumination light being reflected from the navigation surface towards the imaging lens, the imaging lens being located a working distance above the navigation surface, the working distance ranging from between about 50 mm and about 80 mm, wherein the illumination light incident on the navigation surface has a substantially constant diameter as the working distance ranges over the depth of field;
(e) a light detector comprising a sensor pixel array configured to receive at least a portion of the upwardly reflected light passing through the imaging lens and to convert such portion of the reflected light into imaging signals corresponding to individual pixels in the sensor pixel array, and
(f) a navigation processor configured to receive and process the imaging signals corresponding to successively acquired image frames of the sensor pixel array such that output data corresponding to (X,Y) positions of the device with respect to the navigation surface are provided thereby, and further such that the output data include compensation or adjustment for changes in the working distance caused by the device being lifted or lowered in respect of the navigation surface, the changes in the working distance falling within the depth of field of the imaging lens.
2. The navigation input device of claim 1 , wherein the device is configured to move in respect of the navigation surface.
3. The navigation input device of claim 1 , wherein the illumination lens located between the light source and the aperture.
4. The navigation input device of claim 3 , wherein the device is configured such that at least a portion of the illumination light passes downwardly through the illumination lens.
5. The navigation input device of claim 1 , further comprising a beam splitter located in an optical path of the device.
6. The navigation input device of claim 1 , wherein the device is configured to be hand-held by a user.
7. The navigation input device of claim 1 , wherein the device is configured for movement and navigation atop and across the navigation surface.
8. The navigation input device of claim 1 , wherein the navigation processor is configured to process the successively acquired image frames using time domain processing techniques.
9. The navigation input device of claim 1 , wherein the navigation processor is configured to process the successively acquired image frames using frequency domain processing techniques.
10. The navigation input device of claim 1 , wherein the navigation processor is configured to process the successively acquired image frames using Displacement Sensing and Estimation (DSE) techniques.
11. The navigation input device of claim 1 , wherein the device is an optical mouse, a pen-shaped optical mouse, a stylus, a writing instrument, a pen, a measurement device, an alignment device, or a machine alignment device.
12. The navigation input device of claim 1 , wherein differences in image magnification of successively acquired frames resulting from changes in the working distance are less than about 25%.
13. The navigation input device of claim 1 , wherein individual pixels in the sensor array range between about 10 microns and about 20 microns in size, between about 2 microns and about 30 microns in size, between about 10 microns and about 100 microns in size, or between about 5 microns and about 50 microns in size.
14. The navigation input device of claim 1 , wherein the pixel sensor array comprises at least 100 pixels or at least 1,000 pixels.
15. The navigation input device of claim 1 , wherein the light source is a laser, a light emitting diode (LED), an infrared LED, a near-infrared LED, a high-efficiency infrared or near-infrared LED, a VCSEL, an LED or laser source emitting light in the visible spectrum, a white light source, or a UV light source.
16. The navigation input device of claim 1 , wherein the device forms a portion of a system comprising the device and a computer, a processor, a PDA, a mobile telephone, a smart phone, an eBook, a display, a touch screen, a touch pad, an active backplane, an industrial control, or an appliance.
17. A method of navigating across a navigation surface with a navigation input device, comprising:
(a) illuminating the navigation surface with at least a portion of illumination light generated by a light source;
(b) sensing reflected light resulting from at least a portion the illumination light being reflected from the navigation surface and passing through an imaging lens, the imaging lens having a depth of field of about 12 mm, about 14 mm, about 16 mm, about 18 mm, or about 20 mm, the imaging lens being at least one of achromatic, telecentric, or double telecentric, and further being located a working distance above the navigation surface, the working distance ranging from between about 50 mm and about 80 mm, wherein the illumination light incident on the navigation surface has a substantially constant diameter as the working distance ranges over the depth of field, the sensed reflected light being employed to generate imaging signals;
(c) generating, from the imaging signals, successive image frames corresponding to images of the reflected light as the device and the navigation surface move in respect of one another, and
(d) processing the successive image frames such that output data corresponding to (X,Y) positions of the device with respect to the navigation surface are provided thereby, and further such that the output data include compensation or adjustment for changes in the working distance caused by the device being lifted or lowered in respect of the navigation surface, the changes in the working distance falling within the depth of field of the imaging lens.
18. The method of claim 17 , further comprising passing the illumination light through an illumination lens located between the light source and the aperture.
19. The method of claim 17 , further comprising processing the successively acquired image frames, in the processor, using Displacement Sensing and Estimation (DSE) processing techniques.
20. The method of claim 17 , further comprising processing the successively acquired image frames, in the processor, using time-domain processing techniques.
21. The method of claim 17 , further comprising processing the successively acquired image frames, in the processor, using frequency-domain processing techniques.
22. The method of claim 17 , wherein, the device moves across the navigation surface.
23. The method of claim 17 , wherein the navigation surface moves across the navigation input device.
24. The method of claim 17 , further comprising passing the illumination light through the imaging lens.
25. The method of claim 17 , wherein the device is an optical mouse, a pen-shaped optical mouse, a stylus, a writing instrument, a pen, a measurement device, an alignment device, or a machine alignment device.
26. The method of claim 17 , wherein the device forms a portion of a system comprising the device and a computer, a processor, a PDA, a mobile telephone, a smart phone, an eBook, a display, a touch screen, a touch pad, an active backplane, an industrial control, or an appliance.