TW202001283A - Time-of-flight device and method for identifying image using time-of-flight device - Google Patents

Abstract

The present invention provides a time-of-flight (TOF) device. The TOF device includes an infrared light emitter and an infrared light receiver, the infrared light emitter emits a infrared light along a first direction (X-axis), a right angle prism disposed on a movable base, the infrared light passes through the right angle prism. A first actuator and a second actuator are respectively disposed beside the movable base. By actuating the first actuator, the right angle prism is tilted toward a second direction (Y axis), and by actuating the second actuator, the right angle prism is tilted toward a third direction (Z axis), and the second direction and the third direction are both perpendicular to the first direction.

Description

Time-of-flight distance measuring device and method for identifying images using time-of-flight distance measuring device

The invention relates to the field of optics, in particular to an improved time-of-flight distance measuring device and a method for identifying images using the time-of-flight distance measuring device. The time-of-flight distance measuring device of the present invention has a higher resolution.

A time-of-flight (TOF) device is a three-dimensional sensing device. The principle is to emit a light source (such as infrared light) to the target, and then receive the infrared light reflected back from the target, and determine the distance between the device and the target by calculating the time difference between infrared light emission and reception.

The infrared light receiving area of the time-of-flight distance-measuring device includes many arrays of photosensitive regions, each of which can represent a pixel, that is, the number of the above-mentioned photosensitive regions is the resolution of the time-of-flight distance-measuring device High and low. The greater the number of photosensitive areas, the higher the resolution of the time-of-flight distance measuring device.

However, since the light intensity of the infrared light reflected back from the target will be weakened, each photosensitive area should maintain a certain area to effectively receive the reflected infrared light. In this way, the number of photosensitive areas will be limited if the total unit area is unchanged, which means that the resolution cannot be effectively improved. In terms of current technology, the resolution of the time-of-flight distance measuring device is difficult to exceed the standard VGA (Video Graphics Array) image quality, which is 640*480. The resolution of most time-of-flight distance measuring devices is 320*240 or even lower.

Therefore, in the current technology, the resolution of the time-of-flight distance measuring device is insufficient, which is not conducive to the application of the face recognition function. For example, please refer to FIG. 1, which illustrates a schematic diagram of a time-of-flight distance measuring device with insufficient resolution applied to the face recognition function. As shown in FIG. 1, a time-of-flight ranging (TOF) device 100 is provided on a gate 102, and when a target 104 approaches the gate 102, the TOF device 100 is activated and performs face recognition. However, if the target 104 is far away from the gate (L1, for example, 3 meters or more), the TOF device 100 is activated, and the recognized face area is too small and the resolution is insufficient to clearly understand the details of the face. , Which in turn affects subsequent identity authentication. On the other hand, if the target object 104 is closer to the gate (for example, L2, assuming a distance of 1 meter or less), the TOF device 100 is activated. Although the detailed features of the partial face can be judged more clearly, this From time to time, you may face the problem that the face area exceeds the picture.

Therefore, if the resolution of the time-of-flight distance measuring device can be improved, the above problems can be effectively solved.

The invention provides a time-of-flight (TOF) device, which includes an infrared light emitter and an infrared light receiver, wherein the infrared light emitter emits an infrared light along a first direction, a A right-angle three-legged arbitrarily arranged on a movable base, wherein the infrared light passes through the right-angle three-legged arbitrarily arranged, and a first actuator and a second brake are respectively arranged beside the movable base, wherein by starting The first brake makes the right-angle three-legged slanted in a second direction, and by activating the second brake, the right-angled three-legged slanted in the third direction, and the second direction and the third The directions are perpendicular to the first direction.

The invention also provides a method for recognizing images by using time-of-flight (TOF) devices. Firstly, a time-of-flight distance measuring device is provided. The time-of-flight distance measuring device includes an infrared light emitter and an infrared light receiver, wherein the infrared light emitter emits an infrared light along a first direction, and a right-angled triangular The mirror is arranged on a movable base, wherein the infrared light passes through the right-angle three-lens, and a first actuator and a second brake are respectively arranged beside the movable base, wherein by activating the first The brake makes the right-angle three-legged slanted to tilt in a second direction. By activating the second brake, the right-angled three-legged slanted mirror is inclined in a third direction, and the second direction and the third direction are both The first direction is perpendicular. Then, when a target is close to the time-of-flight distance measuring device, the time-of-flight distance measuring device is activated to recognize the first range of the target object, and a first three-dimensional recognition result map is obtained, and then by starting the first cause Actuator and the second brake, adjust the angle of the right-angle three-lens, and change the irradiation angle of the infrared light, then, after the irradiation angle of the infrared light is changed, identify the second range of the target, and Obtain a second 3D recognition result map.

The invention provides an improved time-of-flight distance measuring device, which uses an actuator to control the angle of a right-angled samara, and then changes the irradiation angle of infrared light, so that the time-of-flight distance measuring device has a scanning function. The resolution and detectable range of the original time-of-flight distance-measuring device are a fixed value. If the scanning function is used, the target is divided into different areas and scanned and identified separately, and then the recognition results of different areas are combined to obtain a Complete scan pattern. As a result, the resolution and detection range will be greatly improved.

In order to enable those of ordinary skill in the art of the present invention to further understand the present invention, the preferred embodiments of the present invention are specifically enumerated below, and in conjunction with the accompanying drawings, the composition of the present invention and the desired effects are described in detail .

For the convenience of explanation, the illustrations of the present invention are only schematics to make it easier to understand the present invention, and the detailed proportions can be adjusted according to the design requirements. As described in the text, the relative relationship of the relative elements in the figure should be understood by those skilled in the art as it refers to the relative position of the objects, so they can be turned over to present the same components, which should belong to the The scope of disclosure is described here first.

The present invention provides an improved time-of-flight distance measuring device, which can solve the problems mentioned in the foregoing prior art paragraphs. First, please refer to FIG. 2, which shows a schematic structural diagram of the time-of-flight distance measuring device of the present invention. As shown in FIG. 2, the time-of-flight distance measuring device 200 of the present invention at least includes a main part 202 and a right-angle three-lens 204, the right-angle three-lens 204 is disposed on a movable base 206, and the first actuator 208A and the second actuator 208B are provided beside the movable base 206 (for example, along the Y axis and the Z axis in FIG. 2 ). The main part 202 includes a light source emitting device and a light source receiving device, wherein the light source emitting device is, for example, an infrared light emitting device, and the light source receiving device is, for example, an infrared light receiving device. The infrared light emitting device is used to emit a single laser infrared light or multiple laser infrared lights at the same time. The emitted infrared light will be reflected after irradiating a target. Generally speaking, the infrared light receiver includes an array of photosensitive regions to receive infrared light reflected by the target. In addition, the main part 202 also includes a memory and a processor to record the time difference between infrared light emission and reception. And calculate the distance between the device and the target. To put it simply, the main part 202 of the time-of-flight distance measuring device 200 according to the present invention has the same function as a conventional time-of-flight distance measuring device, that is, it uses transmitting and receiving infrared light to calculate the distance of the target object With depth. Since the time-of-flight distance measuring device is currently known technology, it will not be repeated here.

As mentioned above, in order to effectively receive the reflected infrared light, the resolution of the current time-of-flight distance measuring device will be limited. Regarding the main part 202 of the time-of-flight distance measuring device 200 in the present invention, the highest resolution it has is W*H. Here, W is the number of horizontal pixels of the screen of the time-of-flight distance measuring device, and H is the number of vertical pixels of the screen of the time-of-flight distance measuring device. For example, according to the current technology, in this embodiment, the highest resolution that the main part 202 can have is set to 320*240, but the present invention is not limited to this. In other words, in the present invention, the improved time-of-flight ranging device 200 is composed of a main part 202 with a resolution of W*H (this part is equal to a conventional complete time-of-flight ranging device) plus other It is made up of parts (such as right-angled prism 204, movable base 206 and actuator).

Among them, the right-angle three-lens 204 will be disposed on the movable base 206, and further includes two actuators, respectively defined as a first actuator 208A and a second actuator 208B, respectively disposed beside the movable base 206 Two different directions. The first actuator 208A and the second actuator 208B include Voice Coil Motor (VCM), Micro Electro Mechanical System (MEMS), Shape Memory Alloys (SMA) or other The electronic control device includes a device that generates structural changes by signal control. In this embodiment, the angle of the movable base 206 is changed by activating the first actuator 208A or the second actuator 208B, wherein the variable angle of the movable base 206 is preferably greater than or equal to 100 degrees, but not limited to this . In more detail, the infrared light emitted by the main part 202 will pass through the right-angled prism 204 along a first direction (for example, the X axis in Figure 2), and after being reflected by the right-angled prism 204, it will face another direction (For example, Z-axis) transmission, that is, the lens (not shown) of the time-of-flight distance measuring device is set in the Z-axis direction. Such a configuration can effectively use space and is conducive to miniaturization of the overall structure. The first actuator 208A is disposed beside the movable base 206. When the first actuator 208A is activated, the right-angle three-lens 204 can tilt or rotate in a second direction (for example, the Y axis). On the other hand, the second actuator 208B is also disposed next to the movable base 206. When the second actuator 208B is activated, the right-angled Machi 204 will tilt or rotate in a third direction (such as the Z axis) . The first direction, the second direction and the third direction are all perpendicular to each other. Therefore, by activating the first actuator 208A or the second actuator 208B, it is possible to change the position or angle of the movable base 206 and the right-angle three-lens 204, when the infrared light emitted by the main part 202 is along the X-axis direction When passing through the right-angled prism 204, the irradiation direction of infrared light will be controlled by the right-angled prism 204.

In the present invention, by adjusting the first actuator 208A and the second actuator 208B, the irradiation direction of the infrared light emitted by the main part 202 can be changed, thereby achieving a similar scanning effect. In more detail, the resolution and detectable range of the original main part 202 are a fixed area. If the scan function is used, the target is divided into different areas and the scan identification is performed sequentially, and then the identification results of the different areas are synthesized. , You can get a complete scan pattern. For example, if the target object is divided into four regions (for example, the upper left region, the upper right region, the lower left region, and the lower right region) to be recognized in sequence, and then the respective recognition results are combined into a final recognition image. In this way, the detection range will be four times the original detection range, and the resolution is also four times the original (that is, 2W*2H, if the original resolution is 320*240, the recognition map after the synthesis of four images The resolution should be 640*480).

FIG. 3 is a schematic diagram of applying the improved time-of-flight distance measuring device 200 of the present invention to face recognition. As shown in FIG. 3, a gate 102 is provided with a time-of-flight distance measuring device 200. When a target 104 approaches the time-of-flight distance measuring device 200, the time-of-flight distance measuring device 200 is activated and face recognition is performed. The difference from the situation shown in FIG. 1 is that in this embodiment, when the target 104 is sufficiently close to the time-of-flight distance measuring device 200 (for example, the distance is L2), the time-of-flight distance measuring device 200 will make multiple human faces In the recognition step, different regions of the human face (target) are sequentially recognized, and finally the recognition results of each region are synthesized. As shown in Figure 3, in this embodiment, the range of the human face is divided into four different areas, namely the upper left area, the upper right area, the lower left area, and the lower right area, and the scanning recognition is performed separately, and each area has its own W *H resolution. It is worth noting that the step of identifying each area includes the infrared light emitted by the time-of-flight distance measuring device 200 to illuminate a part of the face, and then the infrared light reflected by the human face is reflected by the time-of-flight distance measuring device 200 Received by the infrared light receiver, and by measuring the time difference between infrared light emission and reception, the distance and depth of the human face are calculated, and a three-dimensional recognition result map is obtained. In addition, the above-mentioned different regions may not overlap with each other at all, or may partially overlap with each other (for example, near a boundary portion). Taking this embodiment as an example, the face range is divided into four different areas. The final synthesized recognition result has four times the resolution, which is equivalent to 2W*2H, and the recognition screen can also accommodate the full face size, which is beneficial to the details of the face Feature determination and subsequent identity verification steps.

It is understandable that in the above method, the target object (for example, a human face) is divided into four regions, and then the face recognition steps are sequentially performed. However, in other embodiments of the present invention, the target object may be divided into more or fewer regions, and the number of regions only needs to satisfy two or more to fall within the scope of the present invention. Therefore, the present invention provides a structure of a time-of-flight distance measuring device with higher resolution, and a method of identifying a target using the structure. For example, the highest resolution of the main part 202 of the time-of-flight distance measuring device 200 of the present invention usually does not exceed 640*480, such as 320*240, however, after scanning different areas, then the identification of each area After the results are synthesized, the resolution of the final recognition result pattern will be greater than or equal to 640*480, for example, 1280*960 or higher resolution.

The flowchart of the present invention for recognition can refer to FIG. 4, which shows the flowchart of the present invention for identifying images using the time-of-flight distance measuring device. First, as in step S1, the target object (such as a human face) approaches the time-of-flight distance measuring device, and then In step S2, the time-of-flight distance measuring device is activated to detect a first range of the target, and a first three-dimensional recognition result map is obtained. Then, in step S3, by activating the first actuator and the second brake, Adjust the angle of the right-angle San Yan, and change the irradiation angle of infrared light. Next, in step S4, after the irradiation angle of the infrared light is changed, the time-of-flight distance measuring device is activated to recognize the second range of the target and obtain a second stereoscopic recognition result map, and then in step S5, the first The three-dimensional recognition result graph and the second three-dimensional recognition result graph are combined into a final three-dimensional recognition result graph. It is worth noting that in the process of FIG. 4, two different regions of the target object are separately recognized, so the first three-dimensional recognition result map and the second three-dimensional recognition result map are generated separately, but in other embodiments of the present invention , The target object can be divided into more regions, and more stereo recognition result maps will be generated, that is to say, between step S4 and step S5 may include other steps of adjusting the right-angle three-legged and the face recognition step, Finally, all the three-dimensional recognition results are synthesized. As a result, the resulting stereo recognition result map will have a higher resolution. This step also falls within the scope of the present invention.

To sum up, the present invention provides an improved time-of-flight distance measuring device, which uses an actuator to control the angle of the right-angle Sanyin, thereby changing the irradiation angle of infrared light, so that the time-of-flight distance measuring device has a scanning function. The resolution and detectable range of the original time-of-flight distance-measuring device are a fixed value. If the scanning function is used, the target is divided into different areas and scanned and identified separately, and then the recognition results of different areas are combined to obtain a Complete scan pattern. As a result, the resolution and detection range will be greatly improved. The above are only the preferred embodiments of the present invention, and all changes and modifications made in accordance with the scope of the patent application of the present invention shall fall within the scope of the present invention.

100‧‧‧Time-of-flight ranging device 102‧‧‧Gate 104‧‧‧Target 200‧‧‧Time-of-flight ranging device 202‧‧‧Main part 204‧‧‧Rectangular Machiro 206‧‧‧Moveable base 208A‧‧‧ First actuator 208B‧‧‧ Second actuator W‧‧‧ Number of horizontal pixels H‧‧‧ Number of vertical pixels S1, S2, S3, S4, S5‧‧‧ Steps

FIG. 1 shows a schematic diagram of a time-of-flight distance measuring device with insufficient resolution applied to the face recognition function. FIG. 2 is a schematic structural diagram of the time-of-flight distance measuring device of the present invention. FIG. 3 is a schematic diagram of applying the improved time-of-flight distance measuring device of the present invention to face recognition. FIG. 4 is a flow chart of the present invention using a time-of-flight distance measuring device to identify images.

200‧‧‧Flight time ranging device

202‧‧‧Main part

204‧‧‧Right Angle

206‧‧‧Moving base

208A‧‧‧First actuator

208B‧‧‧Second actuator

Claims (15)

A time-of-flight (TOF) device includes: an infrared light emitter and an infrared light receiver, wherein the infrared light emitter emits an infrared light along a first direction; a right angle three稜鏡, set on a movable base, wherein the infrared light passes through the right-angle three 珜鏡; and a first actuator and a second brake, respectively, located next to the movable base, wherein by activating the first A brake, so that the right-angle three-legged pitcher is tilted in a second direction, and by activating the second brake, the right-angled three-legged mirror is tilted in a third direction, and both the second direction and the third direction Perpendicular to the first direction. The time-of-flight distance measuring device as described in item 1 of the patent application scope, wherein the first actuator and the second actuator include a voice coil motor (Voice Coil Motor, VCM) and a micro electro mechanical system (Micro Electro Mechanical System , MEMS) or Shape Memory Alloys (SMA). The time-of-flight distance measuring device as described in item 1 of the patent application range, wherein the variable angle of the movable base is greater than or equal to 100 degrees. The time-of-flight distance-measuring device as described in item 1 of the patent application scope, wherein the infrared light emitted by the infrared light emitter is irradiated toward the third direction after being reflected by the right-angled prism. The time-of-flight distance measuring device as described in item 4 of the patent application range, wherein the infrared light irradiates an external target, and the infrared light reflected by the target is received by the infrared light receiver. The time-of-flight distance measuring device as described in item 1 of the patent application scope, wherein the resolution of the time-of-flight distance measuring device is less than or equal to 640*480. A method for identifying images using a time-of-flight (TOF) device includes: providing a time-of-flight distance-measuring device, the time-of-flight distance-measuring device including: an infrared light emitter and an infrared light receiver , Wherein the infrared light emitter emits an infrared light along a first direction; a right-angle three-lens, set on a movable base, wherein the infrared light passes through the right-angle three-lens; a first actuator And a second brake, which are respectively arranged beside the movable base, wherein by activating the first brake, the right-angled Mikaru is tilted in a second direction, and by activating the second brake, the right-angled three Lei Han is inclined in a third direction, and both the second direction and the third direction are perpendicular to the first direction; when a target approaches the time-of-flight distance measuring device, the time-of-flight distance measuring device is activated to identify The first range of the target object and obtain a first three-dimensional recognition result map; by activating the first actuator and the second brake, adjust the angle of the right-angle three-lens, and change the irradiation angle of the infrared light ; After the irradiation angle of the infrared light is changed, identify the second range of the target object, and obtain a second three-dimensional recognition result map. The method as described in item 7 of the patent application scope further includes synthesizing the first three-dimensional recognition result graph and the second three-dimensional recognition result graph into a final three-dimensional recognition result graph. The method as described in item 8 of the patent application scope, wherein the resolution of the final stereo recognition result graph is greater than or equal to 640*480. The method as described in item 7 of the patent application scope, wherein the resolution of the time-of-flight ranging device is less than or equal to 640*480. The method as described in item 7 of the patent application scope, wherein the step of obtaining the first stereo recognition result map includes: emitting an infrared light from the infrared light emitter to illuminate a part of the range of the target; after being reflected by the target The infrared light is received by the infrared light receiver; and by measuring the time difference between the infrared light emission and reception, the distance and depth of the target object are calculated, and the first three-dimensional recognition result map is obtained. The method according to item 7 of the patent application scope, wherein the first range of the target object and the second range of the target object do not overlap each other. The method according to item 7 of the patent application scope, wherein the first range of the target object and the second range of the target object partially overlap each other. The method as described in item 7 of the patent application scope, wherein the first actuator and the second actuator include a voice coil motor (Voice Coil Motor (VCM), a micro electro mechanical system (MEMS) or Shape Memory Alloys (SMA). The method as described in item 7 of the patent application range, wherein the variable angle of the movable base is greater than or equal to 100 degrees.

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