The present disclosure describes an optoelectronic device comprising a light processing device and, in particular, a light processing device comprising a through-opening.
Systems for performing light-based analysis or light-based capture of one or more images are well known in the art and may be characterized by the inclusion of one or more light sources and one or more sensors. As used herein, the term “light” encompasses any electromagnetic radiation that may be useful in such devices including, but not limited to, the human-visible spectrum typically defined as including wavelengths between about 380 to 700 nanometers. In such systems, light provided by the light source(s) is used to illuminate an object or scene and light reflected off such object/scene is then captured by the sensor(s) for analysis and/or image capture.
An example of such a system known in the prior art is illustrated in
While the reflective system 100 of
An example of an alternative reflective system 200 is illustrated in
An example of an application of the optoelectronic device 201 is further illustrated with respect to the
While the systems illustrated in
Generally, the instant disclosure describes an optoelectronic device comprising a light processing device that, in turn, comprises at least one light sensor, the light processing device further comprising a device through-opening. The optoelectronic device further comprises a light source supported by a light source carrier adjacent to but not in direct contact with the light processing device, the light source configured to align with the device through-opening in the light processing device such that light emitted by the light source emerges from the device through-opening. In this embodiment, the light processing device comprises one or more first connection elements and the light source carrier comprises one or more second connection elements corresponding to the first connection elements, the light processing device being operatively connected to the light source carrier via the first connection elements and the corresponding second connection elements.
In an embodiment, the light processing device comprises a semiconductor substrate and the at least one light sensor is formed in the semiconductor substrate. The light sensor may comprise a backside-illuminated sensor. Furthermore, at least one signal processor may be formed in the semiconductor substrate and operatively connected to the at least one light sensor. Further still, at least two signal processors may be formed in the semiconductor substrate and electrically isolated from each other.
In an embodiment, the at least one light sensor is configured to receive light traversing an upper surface of the light processing device.
In an embodiment, the light source carrier comprises a printed circuit board assembly.
In another embodiment, the light processing device may further comprise a device carrier disposed at a surface of the light processing device opposite an upper surface of the light processing device, the device carrier comprising a carrier through-opening aligned with the device through-opening. In this embodiment, the light source may be configured to at least extend into the carrier through-opening. Further to this embodiment, the first connection elements may be disposed on the device carrier.
In an embodiment, the light source is configured to at least extend into the device through-opening. The light source may comprise a vertical-cavity surface emitting laser diode.
In an embodiment, an optical element may be operatively connected to the light source.
In an embodiment, the first connection elements and the second connection elements may be configured such that, when coupled together, they provide electrical communication between the light processing device and the light source carrier.
The various embodiments of an optoelectronic device described herein may be incorporated into a rotary or linear encoder comprising an optoelectronic device and a rotatable or linearly movable dimensional scale arranged opposite an upper surface of the light processing device such that the dimensional scale is illuminated by the light source.
In another embodiment, a linear encoder can be provided in which an optoelectronic device described herein detects simultaneously shifts in one or more axes.
In yet another embodiment, an optoelectronic device comprising a light processing device that, in turn, comprises at least one light sensor, the light processing device further comprising a device through-opening. The optoelectronic device further comprises a light source supported by a light source carrier adjacent to but not in direct contact with the light processing device, the light source configured to align with the device through-opening in the light processing device such that light emitted by the light source emerges from the device through-opening. In this embodiment, the wherein the light source carrier is configured to operate as a heat sink for the light source.
The foregoing and other features and advantages will be discussed in detail in the following non-limiting description of specific embodiments in connection with the accompanying drawings, in which:
As used herein, phrases substantially similar to “at least one of A, B or C” are intended to be interpreted in the disjunctive, i.e., to require A or B or C or any combination thereof unless stated or implied by context otherwise. Further, phrases substantially similar to “at least one of A, B and C” are intended to be interpreted in the conjunctive, i.e., to require at least one of A, at least one of B and at least one of C unless stated or implied by context otherwise. Further still, the terms “about,” “approximately,” “substantially” or similar words requiring subjective comparison are intended to mean “within manufacturing tolerances” unless stated or implied by context otherwise.
As used herein, the phrase “operatively connected” refers to at least a functional relationship between two elements and may encompass configurations in which the two elements are directed connected to each other, i.e., without any intervening elements, or indirectly connected to each other, i.e., with intervening elements.
Referring now to
In a presently preferred embodiment, the light processing device 420 comprises a light sensor 422 that is fabricated and operated as a backside-illuminated sensor in accordance with known techniques, although it is appreciated that implementations other than a backside-illuminated sensor may be equally employed. In this embodiment, the light sensor 422 comprises fully depleted bulk silicon having an upper surface 423 that defines an upper surface of the light processing device 420. The fully depleted bulk silicon has a height, H, on the order of few to tens of micrometers, preferably about 50 μm. It is noted that various elements depicted in
As illustrated, the upper surface 423 of the light processing device 420 is configured to face toward the dimensional scale 404, though it is appreciated that, in embodiments other than rotational or linear encoders, the upper surface 423 may face toward another type of object or scene to be analyzed/imaged. As further illustrated, the light sensor 422 also comprises a gate 424 configured to collect photon-induced charge carriers within the fully depleted bulk silicon, thereby providing an electrical signal representative of the light impinging upon the upper surface 423 of the light sensor 422. In a presently preferred embodiment, the upper surface 423 of the light processing device 420 has an antireflection, filter or other optically functional coating or structuring 428 disposed thereon. Formulations for coatings 428 and techniques for their deposition are well known in the art.
The light processing device 420 further comprises electronic circuity 426, preferably in the form of complementary metal-oxide semiconductor (CMOS) circuitry, that may be used to process electrical signals provided by the light sensor 422. For example, in a presently preferred embodiment, the circuitry 426 may comprise signal processing circuitry that may be used to establish digital representations of the electrical signals generated by the light sensor 422 and to perform further signal processing, e.g., filtering, domain transformations, etc., or even artificial intelligence processing for signal conditioning on such digital signals. An advantage of forming the electronic circuitry 426 opposite the upper surface 423 of the light sensor 422, i.e., in accordance with backside-illuminated sensor configuration, is that the light sensor 422 may operate with much greater efficiency because the photoactive region of the light sensor 422 is not obfuscated by electronic circuitry (including corresponding metallic conductors, electrodes and the like) that is typically deployed on the upper surface of so-called frontside-illuminated devices.
The light sensor 422 may comprise multiple light sensors and corresponding electronic circuitry 426 that are electrically isolated from each other. For example, as illustrated in
The fully depleted bulk silicon forming the light sensor 422 includes a device through-opening 440 formed therein. As used herein, a through-opening is an opening that fully traverses the thickness of the element in which it is formed (along whatever direction it is formed, i.e., height, width, depth). Thus, as shown, the device through-opening 440 provides passage through the full height, H, of the light processing device 420, i.e., from beneath a lower surface 425 of the light processing device 420 through the upper surface of the light processing device 420. As illustrated in
As further shown, the optoelectronic device 402 further comprises a light source 450 supported by a light source carrier 430. In an embodiment, the light source 450 is mounted on the light source carrier 430 such that electrical connections may be provided between the light source 450 and the light source carrier 430. For example, in a presently preferred embodiment, the light source carrier 430 may comprise a suitable printed circuit board assembly (PCBA) as known in the art. Similarly, the light source 450 may comprise any suitable light emitting device such a light emitting diode (LED) or a vertical cavity surface emitting laser (VCSEL). For example, in a presently preferred embodiment, the light source 450 comprises a VCSEL operating at a wavelength of about 450 nm, though it is appreciated that other wavelengths (including outside of the visible light spectrum) may be desirable as a matter of design choice. An advantage of using a VCSEL as the light source 450 is that light is emitted from a very small spot, e.g., an active area of about 1.5 μm diameter (full width at half maximum (FWHM), Gaussian) at the 450 nm wavelength. Such reduced dimensions for the light source 450 permits the overall structure of the light processing device 402 to be likewise reduced significantly, which in turn facilitates very compact encoder 400 implementation and potential new application opportunities.
As further depicted in
A benefit of mounting the light source 450 on the light source carrier 430, as compared to prior art devices in which the light source is integrated into the same substrate as the light sensor 422, is that the light source carrier 430 can act as a heat sink to dissipate heat generated by the light source 450 provided that the light source 450 has good thermal coupling with the light source carrier 430. For example, the heat can be well distributed via ground planes embedded in the light source carrier 430. With prior art integrated devices, only comparatively small currents could be used to drive the light source because the heat load generated could otherwise result in device failure. The ability to dissipate more heat as compared to integrated devices permits more current to be used in driving the light source 450, thereby ensuring sufficient illumination levels across applications.
As further shown, the light source 450 is configured on the light source carrier 430 such that, when the first and second connection elements 432, 434 are mated together, the light source 450 aligns with the device through-opening 440 and enters therein. As shown in the illustrated embodiment, the combined height dimensions of the light source 450 and optical element 452 combination are such that a peak of the optical element is approximately flush with the upper surface 423 of the light sensor 420. However, this is not a requirement and it is possible that the light source 450 and/or optical element 452 only extends into the device through-opening 440 less that the full height, H, of the through-opening 440. Alternatively, it is possible that the light source 450 and/or optical element 452 extends past the full height, H, of the through-opening 440, i.e., such that the light source 450 and/or optical element 452 extends past the upper surface 423.
Finally, as further shown in
As illustrated in
Referring now to
As further shown in
Referring now to
In one embodiment, as shown in
In another embodiment, as shown in
The embodiment of
Furthermore, it is understood that the various features illustrated in
combined together.
While the various embodiments in accordance with the instant disclosure have been described in conjunction with specific implementations thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. For example, while the use of the various embodiments of optoelectronic devices in rotary encoders has been described herein as a presently preferred embodiment, it is appreciated that the teachings of the instant disclosure are not necessarily limited in this regard. For example, the presently described optoelectronic devices may be incorporated into image sensors, such as still picture or video cameras, or into image sensors used for three-dimensional range finding. Once again, those skilled in the art will appreciate that the described optoelectronic devices may be incorporated into virtually any application in which it is desired to illuminate an object or scene and obtain light reflected therefrom.
Accordingly, the preferred embodiments of the invention as set forth herein are intended to be illustrative only and not limiting so long as the variations thereof come within the scope of the appended claims and their equivalents.
Number | Date | Country | |
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63396102 | Aug 2022 | US | |
63440045 | Jan 2023 | US |