TW202323851A - Optical sensing device - Google Patents

Abstract

An optical sensing device including a light source module, a reflector module, a lens module and a sensor. The light source module is configured to emit a light beam. The reflector module is disposed downstream of the optical path of the light source module. The reflector module is configured to reflect the light beam onto an object, and configured to reflect the light beam reflected from the object. The lens module is disposed downstream of the optical path of the object. The lens module is configured to converge a light beam reflected from the object on an imaging plane. The sensor is disposed on the imaging plane of the lens module.

Description

Optical Sensing Device

The present invention relates to an optical device, and in particular to an optical sensing device.

Light detection and ranging (LiDAR) is used for distance measurement in a variety of applications and can be incorporated into an ever-growing range of devices. In general, lidar systems measure distance to a target by illuminating the target with a pulsed laser and then sensing the time-of-flight (ToF) of the pulse reflected from the target. Further, a 3D map of the target scene can be generated by scanning laser pulses across the scene and according to angle and time-of-flight.

Traditionally, LiDAR is divided into independent transmitting end (TX) and receiving end (RX). Therefore, the target of the transmitting end (target) and the object plane (object) of the receiving end may not share the same plane, point or angle of view. There are therefore calibration and efficiency issues. Therefore, it is an important and realistic problem to effectively solve this type of problem. In addition, in order to simplify the application requirements of compact size, the lidar path must be further simplified or integrated, so the transmitter and receiver of the lidar must be integrated, and the optical components need to be more efficient to meet the application requirements. Overall potency must also vary. However, such problems and needs still need to be further developed and resolved.

The invention provides an optical sensing device capable of obtaining depth information of an object and other optical image data of the object. In particular, the present invention aims at integrating the transmitting end (TX) and receiving end (RX) of the lidar into a common optical path (common optical path) and mixing and matching aspheric or multi-faceted refractive powers for this optical common path to effectively obtain the object's Depth information and other optical image data of objects. In addition, the present invention also constructs multiple light sources or multiple spectral at the transmitting end and uses diffractive optical elements as light source collection and collimating/focusing, and also uses an aspheric surface for this optical common path Or mix and match multiple diopters to effectively obtain the depth information of the object and other optical image data of the object.

An optical sensing device according to an embodiment of the present invention includes a light source module, a mirror module, a lens, and a sensor. The light source module is suitable for emitting light beams. The reflector module is arranged downstream of the light path of the light source module. The reflector module is adapted to reflect the light beam onto the object, and is adapted to reflect the light beam reflected from the object. The lens is arranged downstream of the optical path of the object. The lens is adapted to focus the light beam reflected from the object on the imaging plane. The sensor is arranged on the imaging plane of the lens.

An optical sensing device according to an embodiment of the present invention includes a light source module, a mirror module, a lens, and a sensor. The light source module is suitable for emitting light beams. The reflector module is arranged downstream of the light path of the light source module. The reflector module is adapted to reflect the light beam onto the object, and is adapted to reflect the light beam reflected from the object. The lens is arranged downstream of the optical path of the object. The lens is adapted to focus the light beam reflected from the object on the imaging plane. The sensor is arranged on the imaging plane of the lens. The path of the light beam projected by the light source module and the image capturing path of the lens are a common path, and the common path contains the mirror module.

Based on the above, in the optical sensing device of the embodiment of the present invention, the illuminated area of the object can form an image on the sensor. Therefore, in addition to obtaining the depth information or depth image of the object, the optical sensing device of the embodiment of the present invention can also obtain other image data of the object, such as the visual image or thermal sensing image of the object. In addition, the optical sensing device of the embodiment of the present invention can also have higher light collection efficiency and better light collection effect.

FIG. 1 is a schematic diagram of an optical sensing device according to an embodiment of the invention. Please refer to Figure 1. The optical sensing device 1 includes a light source module 10 , a beam splitter 22 , a mirror module 24 , a lens 30 and a sensor 40 . The light source module 10 is suitable for emitting the light beam I. The light source module 10 includes multiple or multi-spectral light sources, such as light emitting diodes, organic light emitting semiconductors, polymer light emitting diodes and other solid-state electronic components, or laser light sources. In some embodiments, the light source may be a long-wave infrared (LWIR) light source or other infrared light sources; that is, the light source module 10 may include a heat source, and the light beam I may mainly include long-wave infrared light or infrared light of other wavelength bands . It should be noted that the term "light" herein refers to electromagnetic waves in the visible light, infrared and/or ultraviolet ranges.

The reflector module 24 is disposed downstream of the light path of the light source module 10 . The reflector module 24 is adapted to reflect the beam I from the light source module 10 onto the object O, and is adapted to reflect the beam I reflected from the object O. Referring to FIG. The reflector module 24 may include a micromirror (such as a micromirror manufactured using microelectromechanical system (MEMS) technology) that rotates around two axes, so as to reflect the light beam I from the light source module 10 to the object O different regions on the In this embodiment, the beam splitter 22 is disposed between the light source module 10 and the reflector module 24 , and is disposed upstream of the optical path of the lens 30 . The beam splitter 22 is suitable for passing the light beam I from the light source module 10 , and is suitable for reflecting the light beam I reflected from the mirror module 24 to the lens 30 . That is to say, the path of the light beam projected by the light source module 10 and the imaging path of the lens 30 are a common path, and the common path includes the mirror module 24 .

The lens 30 is arranged downstream of the optical path of the object O. The lens 30 is adapted to focus the light beam I reflected from the object O on the imaging plane IP. In detail, please refer to FIG. 1 , after the light beam I from the light source module 10 passes through the beam splitter 22, it is reflected on the object O by the mirror module 24; the light beam I reflected from the object O passes through the mirror module 24 After being reflected by the beam splitter 22, it is transmitted to the lens 30, and converged on the imaging plane IP through the lens 30. The sensor 40 is disposed on the imaging plane IP of the lens 30 . Therefore, the area of the object O illuminated by the light source module 10 and the mirror module 24 can form an image on the sensor 40 . When the light source module 10 includes a heat source, a thermally induced image of the object O can be formed on the sensor 40 , but the invention is not limited thereto. In this embodiment, the lens 30 includes at least one aspherical lens, so the image quality of the optical sensing device 1 can be improved. In this embodiment, the sensor 40 may include a plurality of pixels 42a, 42b, wherein the pixels 42a, 42b may respectively output electrical signals corresponding to the light received in the individual pixel area.

In this embodiment, the light beam I reflected from the object O is directly imaged on the sensor 40 via the lens 30 . That is, there are no other optical elements between the lens 30 and the sensor 40 . The so-called "no other optical elements" in this article means that on the path of light beam transmission, from one optical element to another optical element, only gas (for example: air) or other environmental media can exist in the space between them. Therefore, the optical sensing device 1 of this embodiment can have higher light collection efficiency and better light collection effect.

The optical sensing device 1 may further include a controller 50 electrically coupled to the sensor 40 . In this embodiment, the controller 50 is configured to include different modes. In the first mode of the controller 50, the controller 50 measures the time interval (time-of-flight) of the light beam I from the light source module 10 to the sensor 40 to obtain the depth information of the object O and/or the reflector module 24 A depth image of the object O within the scanning range. Wherein, the controller 50 can be electrically coupled to the light source module 10 and the mirror module 24 at the same time. In some embodiments, the controller 50 can be configured to control the operation of the light source module 10 and the mirror module 24 . In the second mode of the controller 50, the controller 50 converts the intensity of the light beam I measured by the plurality of pixels 42a, 42b on the sensor 40 into image data to obtain an image of the object O, for example, an object O's visual image or thermal image. Therefore, in addition to obtaining the depth image of the object O, the optical sensing device 1 of this embodiment can also obtain other image data of the object.

In one embodiment, the controller 50 is, for example, a central processing unit (central processing unit, CPU), a microprocessor (microprocessor), a digital signal processor (digital signal processor, DSP), a programmable controller, a programmable The present invention is not limited to a logic device (programmable logic device, PLD), application-specific integrated circuit (application-specific integrated circuit, ASIC) or other similar devices or a combination of these devices. In addition, in one embodiment, each function of the controller 50 can be implemented as a plurality of program codes. These program codes will be stored in a memory, and these program codes will be executed by the controller 50 . Alternatively, in one embodiment, each function of the controller 50 may be implemented as one or more circuits. The present invention does not limit the implementation of the functions of the controller 50 by means of software or hardware.

FIG. 2 is a schematic diagram of a lens according to an embodiment of the present invention. Referring to FIG. 2 , the lens 30 may be the lens 30 in the optical sensing device 1 of FIG. 1 , but the present invention is not limited thereto. In this embodiment, the lens 30 includes a base body 32 and a lens barrel 34 movable relative to the base body 32 . The base body 32 and the lens barrel 34 can be engaged by screwing the inner thread on the base body 32 and the outer thread on the lens barrel 34 . Therefore, the distance between the lens barrel 34 and the sensor 40 can be adjusted according to requirements, so that the optical sensing device 1 can obtain better image quality. In this embodiment, the lens 30 includes three lenses 36a, 36b, 36c having diopters or optical powers. This three-piece lens group can be applied to a field of view (Field of View) of about 60-70 degrees or within. This type of lens group can be divided into two groups. From the object side to the image side, it is the front group and the rear group. The front group includes 1 to 2 lenses with diopters. The diopter of the front group lenses is from the object side to the image side. The order is "Negative, Negative" or "Negative, Positive". The rear group includes 1 to 2 lenses with diopters. The diopters of the rear group lenses are in order from the object side to the image side. They are "positive, positive" or "positive" respectively, but the present invention is not limited thereto. In this embodiment, the front group of lenses includes a lens 36a, and the rear group of lenses includes a lens 36b and a lens 36c, wherein the diopter of the lens 36a is positive, the diopter of the lens 36b is positive, and the diopter of the lens 36c is negative, but the present invention is not limited to this. As shown in FIG. 2 , three lenses 36 a , 36 b , and 36 c are fixed in the lens barrel 34 .

FIG. 3 is a schematic diagram of a lens according to an embodiment of the present invention. Please refer to Fig. 3, the lens 30' can be similar to the lens 30 of Fig. 2, but the number of lenses and the shape, size, spacing of each lens surface, and the structure of the lens barrel can be different. In this embodiment, the front group of lenses includes a lens 36a', and the rear group of lenses includes a lens 36b' and a lens 36c', wherein the diopter of the lens 36a' is negative, the diopter of the lens 36b' is positive, and the diopter of the lens 36c' is positive , but the present invention is not limited thereto.

FIG. 4 is a schematic diagram of a lens according to an embodiment of the present invention. Please refer to Fig. 4, lens 30 " can be similar to lens 30 of Fig. 2, but the quantity of lens and the shape, size, interval of each lens surface, and the structure of lens barrel can be different. In the present embodiment, front group eyeglass comprises Lens 36a'', the rear lens group includes lens 36b'', lens 36c'' and lens 36d'', wherein the diopter of lens 36a" is negative, the diopter of lens 36b" is negative, the diopter of lens 36c" is positive, and the diopter of lens 36c" is positive. 36d" is positive, but the invention is not limited thereto.

Fig. 5 is a schematic diagram of a light source module according to an embodiment of the present invention. Referring to FIG. 5 , the light source module 10a may be similar to the light source module 10 in the optical sensing device 1 of FIG. 1 . In this embodiment, the light source module 10 a includes a light source 12 and a diffractive optical element (DOE) 14 . The diffractive optical element 14 may be a diffraction grating or an optical layer including one or more slits and/or pinholes; or, the diffractive optical element 14 has a surface structure with specially designed intervals and periods. The diffractive optical element 14 is configured so that the initial light beam _I0 from the light source 12 can become a light beam I with a specific light field distribution after passing through the diffractive optical element 14 .

FIG. 6 is a schematic diagram of an optical sensing device according to another embodiment of the present invention. Please refer to Figure 6. The optical sensing device 1' of the embodiment of FIG. 6 is similar to the optical sensing device 1 of FIG. 1, and the differences are as follows. The optical sensing device 1' That is to say, the receiving end (RX) of the optical sensing device 1' has a reflective lens between the mirror group and the sensing element or in the mirror group to bend the light path and make the overall optical volume more compact.

To sum up, in the optical sensing device of the embodiment of the present invention, the lens is suitable for converging the light beam reflected from the object on the imaging plane, and the sensor is arranged on the imaging plane of the lens, so that the irradiated area of the object can be An image is formed on the sensor. Therefore, in addition to obtaining the depth information or depth image of the object, the optical sensing device of the embodiment of the present invention can also obtain other image data of the object, such as the visual image or thermal sensing image of the object. In addition, the optical sensing device of the embodiment of the present invention can also have higher light collection efficiency and better light collection effect.

1, 1': optical sensing device 10, 10a: light source module 12: light source 14: diffractive optical element 22: beam splitter 24: mirror module 26: mirror optical element 30, 30', 30": lens 32: seat body 34: lens barrel 36a, 36b, 36c, 36a', 36b', 36c', 36a", 36b", 36c", 36d": lens 40: sensor 42a, 42b: multiple pixels 50 : Controller I, I ₀ : Beam IP: Imaging plane O: Object

FIG. 1 is a schematic diagram of an optical sensing device according to an embodiment of the invention. 2 to 4 are schematic diagrams of lenses according to different embodiments of the present invention. Fig. 5 is a schematic diagram of a light source module according to an embodiment of the present invention. FIG. 6 is a schematic diagram of an optical sensing device according to another embodiment of the present invention.

1: Optical sensing device

10: Light source module

22: beam splitter

24: Mirror module

30: Lens

40: sensor

42a, 42b: multiple pixels

50: Controller

I: Beam

IP: imaging plane

O: object

Claims (20)

An optical sensing device, comprising: A light source module suitable for emitting light beams; A reflector module, arranged downstream of the optical path of the light source module, the reflector module is suitable for reflecting the light beam onto an object, and is suitable for reflecting the light beam reflected from the object; a lens arranged downstream of the optical path of the object, the lens being adapted to converge the light beam reflected from the object on an imaging plane; and The sensor is arranged on the imaging plane of the lens. The optical sensing device as claimed in claim 1, wherein the light beam reflected from the object is directly imaged on the sensor via the lens. The optical sensing device as claimed in claim 1, comprising a mirror optical element between the lens and the sensor. The optical sensing device as claimed in claim 1, wherein the lens comprises at least one aspheric lens. The optical sensing device as claimed in claim 4, wherein the lens includes three lenses with diopters. The optical sensing device as claimed in claim 1, wherein the lens includes a base and a lens barrel movable relative to the base. The optical sensing device as claimed in claim 1, wherein the light source module includes a heat source. The optical sensing device according to claim 1, wherein the light source module includes multiple or multi-spectral light sources and diffractive optical elements. The optical sensing device according to claim 1, further comprising a beam splitter arranged upstream of the optical path of the lens, the beam splitter is adapted to allow the light beam from the light source module to pass through, and is adapted to The light beam reflected by the mirror module is reflected to the lens. The optical sensing device as claimed in claim 1, further comprising a controller electrically coupled to the sensor, wherein the controller is configured such that in a first mode of the controller, the controller measuring the time interval of the light beam from the light source module to the sensor, and in the second mode of the controller, the controller sends a plurality of pixels on the sensor to The measured beam intensity is converted into image data. An optical sensing device, comprising: a light source module, adapted to emit light beams; a reflector module, disposed downstream of the optical path of the light source module, and the reflector module is adapted to reflect the light beams onto an object, and adapted to reflect the light beam reflected from the object; a lens, arranged downstream of the optical path of the object, the lens is adapted to converge the light beam reflected from the object on an imaging plane; and a sensor , arranged on the imaging plane of the lens; and the beam path projected by the light source module is a common path with the imaging path of the lens, and the common path contains a mirror module. The optical sensing device as claimed in claim 11, wherein the light beam reflected from the object is directly imaged on the sensor via the lens. The optical sensing device as claimed in claim 11, comprising a mirror optical element between the lens and the sensor. The optical sensing device as claimed in claim 11, wherein the lens includes at least one aspherical lens. The optical sensing device as claimed in claim 14, wherein the lens includes three lenses with diopter or optical power. The optical sensing device as claimed in claim 11, wherein the lens includes a base and a lens barrel movable relative to the base. The optical sensing device as claimed in claim 11, wherein the light source module includes a heat source. The optical sensing device as claimed in claim 11, wherein the light source module includes multiple or multi-spectral light sources and diffractive optical elements. The optical sensing device according to claim 11, further comprising a beam splitter arranged upstream of the optical path of the lens, the beam splitter is adapted to allow the light beam from the light source module to pass through, and is adapted to The light beam reflected by the mirror module is reflected to the lens. The optical sensing device as claimed in claim 11, further comprising a controller electrically coupled to the sensor, wherein the controller is configured such that in a first mode of the controller, the controller measuring the time interval of the light beam from the light source module to the sensor, and in the second mode of the controller, the controller sends a plurality of pixels on the sensor to The measured beam intensity is converted into image data.

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