Patent Description:
At present, a pyroelectric infrared sensor (PIR) and a Fresnel lens are usually combined to sense human motion. The Fresnel lens has a special optical principle, which can generate alternating visible regions and blind regions in front of the pyroelectric infrared sensor (the visible regions refer to the regions where light can pass through the lens, and the blind regions refer to the regions where light cannot pass through the lens). When someone moves in front of the lens, the infrared rays emitted by a human body continually alternate between the visible regions and the blind regions, so that infrared signals received by the pyroelectric infrared sensor are input to the pyroelectric infrared sensor in a form of a strong or weak pulse. Thus the pyroelectric infrared sensor can sense the moving human body.

However, the pyroelectric infrared sensor products in the prior art generally have problems such as small sensing range, insensitive sensing action and the like. Even though there are a small number of similar products with high sensitivity, they have a problem of high price. Therefore, it is necessary to develop a pyroelectric infrared sensor device to achieve a balance among the sensing distance, the sensing sensitivity and the product cost of the pyroelectric infrared sensor products.

In <CIT>, a detection system comprising three sensors and three lenses is disclosed. The first lens of the described detection system is configured such that radiation from a direction that is perpendicular to the first lens is received by first sensor over a first horizontal coverage angle of <NUM> degrees. The second lens is configured such that the radiation that originates from a direction that is perpendicular to the second lens is received by a second sensor over a second horizontal coverage angle of <NUM> degrees. Finally, the third lens is configured such that radiation from a direction that is perpendicular to the third lens is received by a third sensor over a third horizontal coverage angle of <NUM> degrees.

In addition, in <CIT>, a passive infrared detector with at least three sub-detectors is disclosed. Each of the described sub-detectors is operative to receive infrared radiation from a corresponding one of at least three sub fields-of-view. Each sub field-of-view is exclusively defined by an optical element which does not define any other sub field-of-view. The described detector comprises a signal processing circuitry, operative to receive output signals from the sub-detectors and to provide a motion detection output.

In view of the above problems, the present disclosure is proposed to provide a pyroelectric infrared sensor based lighting control device and system that overcome the above problems or at least partially solve the above problems.

In order to overcome the mentioned problems, a pyroelectric infrared sensor based lighting control device as defined in independent claim <NUM> is provided. Further preferred embodiments of the present disclosure are defined in the dependent claims.

In the embodiments of the present disclosure, a certain angle between the focusing component and the central axis of the focusing component is designed, thus overlapping regions between the detection regions of the respective pyroelectric infrared sensors mounted on the respective focusing points can be formed. The detection points of the pyroelectric infrared sensors in the respective overlapping regions are more densely distributed, so that the pyroelectric infrared sensors can sense a small amplitude of motion in the detection regions, effectively improving the sensing sensitivity of the pyroelectric infrared sensors. Further, in the embodiments of the present disclosure, the focusing component is designed to include at least two focusing points, and the at least two pyroelectric infrared sensors are respectively disposed at the respective focusing points, thereby enabling the pyroelectric infrared sensor based lighting control device to sense a wide range of infrared signals, and then increasing the area of the regions that sense the external infrared rays.

The above description is only an overview of the technical solutions of the present disclosure, and in order that the technical solutions of the present disclosure are understood more clearly, so as to be implemented according to the contents of the specification, and in order that the above-described and other purposes, features and advantages of the present disclosure are more obvious and understandable, specific implementation modes of the present disclosure are specifically illustrated hereinafter.

Hereinafter, specific embodiments of the present disclosure will be described in detail in conjunction with the accompanying drawings, so that the above-described and other purposes, features and advantages of the present disclosure are more obvious to those skilled in the art.

Those ordinarily skill in the art will clearly understand various other advantages and benefits, through reading the detailed description of preferred implementation modes hereinafter. The accompanying drawings are provided only for illustrating the preferred implementation modes, rather than limiting the present disclosure. Throughout the accompanying drawings, same reference signs usually denote same components. In the drawings:.

Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are illustrated in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited by the embodiments explained here. On the contrary, these embodiments are provided so that the present disclosure may be understood more thoroughly, and the scope of the present disclosure may be completely conveyed to those skilled in the art.

In order to solve the above technical problems, at least an embodiment of the present disclosure provides a pyroelectric infrared sensor based lighting control device, which includes a focusing component and at least two pyroelectric infrared sensors. The device can be mounted on and applied to the top of conference rooms, corridors and other places. Referring to <FIG>, in the claimed invention, the focusing component <NUM> includes at least two curved surface structural portions <NUM> sequentially connected adjacent to each other (for example, the focusing component <NUM> as shown in <FIG> includes four curved surface structural portions <NUM> sequentially connected adjacent to each other). The focusing component <NUM> is rotationally symmetric about a central axis of the focusing component, and an angle is formed between a plane in which the bottom of any one of the curved surface structural portions <NUM> is located and a plane perpendicular to the central axis of the focusing component <NUM>. In this embodiment, the at least two curved surface structural portions <NUM> sequentially connected adjacent to each other are integrally formed.

In the claimed invention, each curved surface structural portion <NUM> corresponds to one focusing point. At least two pyroelectric infrared sensors (not shown in <FIG>) are respectively disposed at respective focusing points, and the focusing component <NUM> is configured to focus external infrared signals onto respective pyroelectric infrared sensors. The at least two pyroelectric infrared sensors are configured to convert changes in the infrared signals into voltage signals when any one of the pyroelectric infrared sensors detects the changes in the infrared signals, and then to control a switch status of a lighting fixture by using the voltage signals.

In the claimed invention, the positions of the respective focusing points of the focusing component <NUM> are determined, and the respective pyroelectric infrared sensors are mounted on the respective focusing points, so that the respective pyroelectric infrared sensors and the central axis of the focusing component <NUM> also form a certain angle, and then overlapping regions are formed between the detection regions of the pyroelectric infrared sensors. The detection points of the pyroelectric infrared sensors are more densely distributed in the respective overlapping regions, and the pyroelectric infrared sensors can sense a small amplitude of motion in the detection regions, effectively improving the sensing sensitivity of the pyroelectric infrared sensors.

In an embodiment of the present disclosure, the focusing component <NUM> is further configured to divide the detection regions detectable by the at least two pyroelectric infrared sensors into a plurality of visible regions and a plurality of blind regions, wherein the plurality of visible regions and the plurality of blind regions are alternately arranged, so that in a case where there is a moving object in the detection regions, the infrared signals generated by the moving object are continuously switched between the plurality of visible regions and the plurality of blind regions to generate the changes in the infrared signals.

Continuing to refer to <FIG>, in the claimed invention, the angle formed between the plane in which the bottom of any one of the curved surface structural portions <NUM> is located and the plane perpendicular to the central axis of the focusing component <NUM> is greater than <NUM> degrees and less than <NUM> degrees, or is greater than -<NUM> degrees and less than <NUM> degrees. For example, an angle of <NUM> degrees or -<NUM> degrees can be preferred. In a case where the angle formed between the plane in which the bottom of any one of the curved surface structural portions <NUM> is located and the plane perpendicular to the central axis of the focusing component <NUM> is <NUM> degrees or -<NUM> degrees, the pyroelectric infrared sensors <NUM> located at the respective focusing points of the focusing component <NUM> have a better sensitivity to the infrared rays.

In an embodiment of the present disclosure, the curved surface structural portions <NUM> may be a plurality of convex lenses sequentially connected adjacent to each other, or may be a plurality of Fresnel lenses sequentially connected adjacent to each other. The specific type of the lens adopted by the curved surface structural portions <NUM> is not limited in the embodiment of the present disclosure.

In another embodiment of the present disclosure, the at least two curved surface structural portions <NUM> sequentially connected adjacent to each other included in the focusing component <NUM> in <FIG> can further be replaced with at least two curved surface structural portions <NUM> (for example, four curved surface structural portions <NUM> are included in <FIG>) included in the focusing component <NUM> as shown in <FIG>. The shape of each of the curved surface structural portions <NUM> is specifically referred to in the schematic diagrams of the curved surface structural portions <NUM> at different angles as shown in <FIG> and <FIG>. The embodiment will be described in detail below.

Referring to <FIG>, in the claimed invention, the focusing component <NUM> of the pyroelectric infrared sensor based lighting control device <NUM> includes at least two curved surface structural portions <NUM> circumferentially arranged around the central axis of the focusing component <NUM>, and the focusing component <NUM> is rotationally symmetric about its central axis. An angle is formed between a plane in which the bottom of any one of the curved surface structural portions <NUM> is located and a plane perpendicular to the central axis of the focusing component <NUM>.

In this embodiment, each curved surface structural portion <NUM> is a hemispherical structure. In the claimed invention, each of the curved surface structural portions <NUM> corresponds to one focusing point. The at least two pyroelectric infrared sensors <NUM> are respectively disposed at the respective focusing points, and the focusing component <NUM> is configured to focus external infrared signals onto the respective pyroelectric infrared sensors <NUM>. The at least two pyroelectric infrared sensors <NUM> are configured to convert changes in the infrared signals into voltage signals when any one of the pyroelectric infrared sensors <NUM> detects the changes in the infrared signals, and then to control the switch status of the lighting fixture by using the voltage signals.

Of course, the curved surface structural portions <NUM> can further be in another structural form, which is not specifically limited in the embodiment of the present disclosure. In this embodiment , the curved surface structural portions <NUM> may be a plurality of convex lenses sequentially connected adjacent to each other, or may be a plurality of Fresnel lenses sequentially connected adjacent to each other. The specific type of the lens adopted by the curved surface structural portions <NUM> is not limited in the embodiment of the present disclosure.

Next, the structure and function of the Fresnel lens will be specifically described.

The Fresnel lens was invented by French physicist FRESNEL, and was pressed using an electroplating mold process and PE (polyethylene) material. The thickness of the lens of the Fresnel lens can generally be <NUM>, and a circle of concentric circles from small to large, shallow to deep are recorded on the surface from the center to the periphery, and the cross-section looks like a sawtooth. If the ring lines composed of concentric circles are dense, the Fresnel lens has a large sensing angle and a far focal distance. If the ring lines are recorded deeply, the Fresnel lens has a far sensing distance and a close focal distance. The closer the infrared rays are to the ring lines, the more concentrated the light passing through the Fresnel lens is and the stronger the rays are.

The circular lines on a same line of the Fresnel lens can form a vertical sensing region, and a horizontal sensing segment is formed between each of the circular lines. more vertical sensing regions of the Fresnel lens there are, the larger the vertical sensing angle is. The longer the lens of the Fresnel lens is, the more horizontal sensing segments there are, and accordingly the larger the horizontal sensing angle is. The more segments of the Fresnel lens there are, the higher the sensing sensitivity is, and a smaller movement of the human body can be sensed. On the contrary, the fewer segments there are, the lower the sensing sensitivity is, and only a larger movement of the human body can be sensed. The blind regions are formed between the respective vertical sensing regions of the Fresnel lens and between the respective horizontal sensing segments. But the concentric circles of the different sensing regions are interlaced, thus reducing the blind regions between the respective segments. Because the Fresnel lens is restricted by the angle of view of the infrared probe, the vertical and horizontal sensing angles are limited, and the area of the lens is also limited The Fresnel lens can be divided into rectangular, square and circular shapes in appearance, and can be divided into single-region multi-segment, double-region multi-segment, multi-region multi-segment in function.

In addition, there are two main functions of the Fresnel lens. One function is to achieve focusing, that is, the infrared signals can be refracted or reflected onto the pyroelectric infrared sensor, and the other function is to divide the detection regions of the pyroelectric infrared sensor into a plurality of visible regions and a plurality of blind regions. Each type of the Fresnel lens has a focusing point, and only the pyroelectric infrared sensor is placed at the focusing points to achieve the best focusing effect, thereby causing the sensitivity of the pyroelectric infrared sensor based lighting control device to be highest.

Referring to <FIG>, the pyroelectric infrared sensor <NUM> is mounted on the focusing point of the Fresnel lens <NUM>, and the external infrared signals (the infrared rays <NUM>) are refracted onto the pyroelectric infrared sensor <NUM> through the Fresnel lens <NUM>. <FIG> is a schematic diagram of the range of the pyroelectric infrared sensor horizontally sensing the infrared signals, and <FIG> is a schematic diagram of the range of the pyroelectric infrared sensor vertically sensing the infrared signals, and the vertical sensing range as shown in <FIG> is <NUM> meters.

In the following, the focusing component <NUM> including four curved surface structural portions <NUM> arranged in a circumferential array around its central axis is an example to introduce the influence degree of different parameters on the sensitivity of the pyroelectric infrared sensor based lighting control device. The greater the sensing density of the pyroelectric infrared sensor to the infrared rays is, the higher the sensitivity of the device is.

Parameter <NUM>, an offset distance between the curved surface structural portions.

<FIG> is a schematic diagram of an array of four curved surface structural portions <NUM> of the focusing component <NUM>, and <FIG> is a sensing density map of the pyroelectric infrared sensors (not shown in <FIG>) mounted on the focusing points of the respective curved surface structural portions <NUM> as shown in <FIG> to the infrared rays.

<FIG> is a schematic diagram of the array after the horizontal distance between the respective curved surface structural portions <NUM> is increased by <NUM> on the basis of the array structure of the four curved surface structural portions <NUM> as shown in <FIG>, and <FIG> is a sensing density map of the pyroelectric infrared sensors (not shown in <FIG>) mounted on the focusing points of the respective curved surface structural portions <NUM> as shown in <FIG> to the infrared rays.

Parameter <NUM>, an offset angle between the curved surface structural portions.

In the respective focusing component <NUM> as shown in <FIG>, the angle between the plane perpendicular to the central axis of the focusing component <NUM> and the plane in which the bottom of any one of the curved surface structural portions <NUM> is located is <NUM> degrees, <NUM> degrees and <NUM> degrees, respectively. The contents as shown in <FIG> are sensing density maps of the pyroelectric infrared sensors (not shown in <FIG>) mounted on the focusing points of the respective curved surface structural portions <NUM> as shown in <FIG> to the infrared rays, respectively.

Parameter three, an offset direction of the curved surface structural portions.

In the respective focusing component <NUM> as shown in <FIG>, the angle between the plane perpendicular to the central axis of the focusing component <NUM> and the plane in which the bottom of any one of the curved surface structural portions <NUM> is located is -<NUM> degrees, degree, degrees and - <NUM> degrees, respectively, and the offset directions of the angles in <FIG> are opposite to those of the angles in <FIG>. The contents as shown in <FIG> are sensing density maps of the pyroelectric infrared sensors (not shown in <FIG>) mounted on the focusing points of the respective curved surface structural portions <NUM> as shown in <FIG> to the infrared rays, respectively.

Parameter <NUM>, a position of the chips of the pyroelectric infrared sensor with respect to the focusing points of the curved surface structural portions (selecting the pyroelectric infrared sensor with <NUM> chips).

In a case where the angle between the plane perpendicular to the central axis of the focusing component and the plane in which the bottom of the respective curved surface structural portion is located is <NUM> degrees and <NUM> degrees, respectively, if any one of the chips of the pyroelectric infrared sensor is located at a focusing point of one curved surface structural portion, the sensing density maps of the pyroelectric infrared sensor to the infrared rays are shown in <FIG> and <FIG>, respectively. If the other chip of the pyroelectric infrared sensor is located at a focusing point of one curved surface structural portion, the sensing density maps of the pyroelectric infrared sensor to the infrared rays are shown in <FIG>, respectively.

Parameter <NUM>, the amount of chips of the pyroelectric infrared sensor.

In a case where the angle between the plane perpendicular to the central axis of the focusing component and the plane in which the bottom of the respective curved surface structural portion is located is <NUM> degrees and <NUM> degrees, respectively, if the amount of the chips of the pyroelectric infrared sensor is two, the sensing density maps of the pyroelectric infrared sensor to the infrared rays are shown in <FIG>, respectively. If the amount of the chips of the pyroelectric infrared sensor is four, the sensing density maps of the pyroelectric infrared sensor to the infrared rays are shown in <FIG> and <FIG>, respectively.

In summary, the offset distance between the curved surface structural portions, the offset direction of the curved surface structural portions, and the position of the chips of the pyroelectric infrared sensor with respect to the focusing points of the curved surface structural portions J <NUM>. have no great influence on the sensing density of the pyroelectric infrared sensor to the infrared rays, that is, there is no great influence on the sensitivity of the pyroelectric infrared sensor based lighting control device.

The offset angle between the curved surface structural portions and the amount of the chips of the pyroelectric infrared sensor have great influence on the sensing density of the pyroelectric infrared sensor to the infrared rays, that is, there is great influence on the sensitivity of the lighting control device based pyroelectric infrared sensor. In a case where the angle between the plane perpendicular to the central axis of the focusing component and the plane in which the bottom of the respective curved surface structural portion is located is constant, the more chips of the pyroelectric infrared sensor there are, the larger the sensing density of the pyroelectric infrared sensors to the infrared rays is.

An embodiment of the present disclosure further provides a pyroelectric infrared sensor based lighting control system. Referring to <FIG>, the pyroelectric infrared sensor based lighting control system <NUM> includes a lighting fixture <NUM> and the pyroelectric infrared sensor based lighting control device <NUM> composed of the focusing component <NUM> as shown in <FIG>. The pyroelectric infrared sensors (not shown in <FIG>) in the pyroelectric infrared sensor based lighting control device <NUM> are electrically connected to the lighting fixture <NUM>, and the pyroelectric infrared sensors are configured to convert changes in the infrared signals into voltage signals when detecting the changes in the infrared signals, and to control the switch status of the lighting fixture <NUM> by using the voltage signals.

In an embodiment of the present disclosure, if the pyroelectric infrared sensors detect the changes in the infrared signals and convert the changes in the infrared signals into the voltage signals, the pyroelectric infrared sensors control the lighting fixture <NUM> to be powered with the voltage signals to realize switching-on of the lighting fixture <NUM>.

In another embodiment of the present disclosure, the pyroelectric infrared sensor based lighting control device can further be the pyroelectric infrared sensor based lighting control device <NUM> as shown in <FIG>.

Claim 1:
A pyroelectric infrared sensor based lighting control device (<NUM>, <NUM>), comprising a focusing component (<NUM>, <NUM>) and at least two pyroelectric infrared sensors (<NUM>),
wherein the focusing component (<NUM>, <NUM>) comprises at least two curved surface structural portions (<NUM>, <NUM>) sequentially connected adjacent to each other, the focusing component (<NUM>, <NUM>) is rotationally symmetric about a central axis of the focusing component, and an angle is formed between a plane in which the bottom of any one of the curved surface structural portions (<NUM>, <NUM>) is located and a plane perpendicular to the central axis of the focusing component (<NUM>, <NUM>) ;
wherein the pyroelectric infrared sensors (<NUM>) and the central axis of the focusing component (<NUM>, <NUM>) define an angle and overlapping regions are formed between detection regions of the pyroelectric infrared sensors (<NUM>);
wherein each of the curved surface structural portions (<NUM>, <NUM>) (<NUM>) corresponds to one focusing point, the at least two pyroelectric infrared sensors (<NUM>) are respectively disposed at respective focusing points, and the focusing component (<NUM>, <NUM>) is configured to focus external infrared signals onto respective pyroelectric infrared sensors (<NUM>); and
wherein the at least two pyroelectric infrared sensors (<NUM>) are configured to convert changes in the infrared signals into voltage signals when any one of the pyroelectric infrared sensors (<NUM>) detects the changes in the infrared signals, and then to control a switch status of a lighting fixture (<NUM>) by using the voltage signals
characterised in that the angle formed between the plane in which the bottom of any one of the curved surface structural portions (<NUM>, <NUM>) is located and the plane perpendicular to the central axis of the focusing component (<NUM>, <NUM>) is greater than <NUM> degrees and less than <NUM> degrees, or is greater than -<NUM> degrees and less than <NUM> degrees.