CN212229221U

CN212229221U - Lens structure for exhaust fan

Info

Publication number: CN212229221U
Application number: CN202021083680.5U
Authority: CN
Inventors: 张宇; 倪嘉辉
Original assignee: Tianjin Aishi Kairui Technology Development Co Ltd
Current assignee: Tianjin Aishi Kairui Technology Development Co Ltd
Priority date: 2020-06-12
Filing date: 2020-06-12
Publication date: 2020-12-25
Anticipated expiration: 2030-06-12

Abstract

The utility model provides a lens structure for exhaust fan, which comprises a hemispherical lens body, wherein the lens body comprises a central visual area positioned at the center of the lens body, a near vision area annularly surrounding the central visual area, and a far vision area annularly surrounding the near vision area; the central visual area is a circular lens with a spherical bulge and is provided with Fresnel lines; the near vision zone and the far vision zone respectively comprise a plurality of small blocks, the small blocks are lens sheets provided with Fresnel lines, and each lens sheet is focused on a sensing area of the pyroelectric sensor in the exhaust fan. The utility model discloses an infrared detection sight area scope that enlarges the air discharge fan provides necessary hardware structure and supports, satisfies the air discharge fan and leaves and open the demand of closing along with being close of human body.

Description

Lens structure for exhaust fan

Technical Field

The utility model belongs to the technical field of the optical accessories, especially relate to a lens structure for air discharge fan.

Background

In the family room, generally all can install the air discharge fan in the bathroom, use the switch of air discharge fan must the manual switch of opening the air discharge fan, still remember the switch of manual switch-off air discharge fan after the use, cause the inconvenience of use, the switch still can produce wearing and tearing under the long condition of live time moreover, consequently has designed among the prior art and uses infrared detection technology at the air discharge fan, judges through infrared detection that the human body is close or leaves, opening and closing of automatic control air discharge fan.

The passive infrared detection technology needs two key elements, namely a pyroelectric infrared sensor PIR and a Fresnel lens; the pyroelectric infrared sensor (PIR) can convert infrared signal change into an electric signal and has an inhibiting effect on white light signals in nature, when no human body moves, the pyroelectric infrared sensor senses only background temperature, and when a human body enters a detection area, the pyroelectric infrared sensor senses a difference signal between the human body temperature and the background temperature through a Fresnel lens; the Fresnel lens has two functions, one is a focusing function, namely, the pyroelectric infrared signal is refracted (reflected) on the PIR, and the second function is to divide the inside of the warning area into a plurality of bright areas and dark areas, so that the moving object entering the warning area can generate a variable pyroelectric infrared signal on the PIR in the form of temperature change, and the PIR can generate a variable electric signal.

In the prior art, the lens structure used on the exhaust fan is single, the visual area range is limited, and the requirement that the exhaust fan is opened and closed along with the approaching and leaving of a human body cannot be well met.

SUMMERY OF THE UTILITY MODEL

The utility model provides a lens structure for air discharge fan can provide necessary hardware structure for enlarging infrared detection visual area scope, satisfies the air discharge fan and leaves and open the demand of closing along with being close of human body.

In order to achieve the above purpose, the technical scheme of the utility model is realized like this:

a lens structure for an exhaust fan comprises a hemispherical lens body, wherein the lens body comprises a central visual area positioned in the center of the lens body, a near vision area annularly surrounding the central visual area, and a far vision area annularly surrounding the near vision area; the central visual area is a circular lens with a spherical bulge and is provided with Fresnel lines; the near vision zone and the far vision zone respectively comprise a plurality of small blocks, the small blocks are lens sheets provided with Fresnel lines, and each lens sheet is focused on a sensing area of the pyroelectric sensor in the exhaust fan.

Furthermore, the sizes and the shapes of all small blocks in the near vision zone are consistent; the small blocks of the far vision area are consistent in size and shape.

Furthermore, the small blocks of the near vision zone correspond to the small blocks of the far vision zone in a one-to-one manner.

Further, the concentric circle center of the fresnel patterns of the central viewing area is located at the central position of the lens sheet of the central viewing area.

Furthermore, every 2 small blocks of the near vision zone are in a group, and the centers of concentric circles of the Fresnel lines of the two small blocks in the group are respectively and correspondingly arranged at the opposite angles of the butt joint of the two small blocks.

Furthermore, the centers of the concentric circles of the fresnel patterns of the small blocks of the far-view area are located on the upper positions of the respective vertical center lines.

Compared with the prior art, the utility model discloses following beneficial effect has:

the utility model provides a lens structure utilizes fresnel principle, provides necessary hardware structure for the infrared detection visual area scope of expanding the air discharge fan and supports, satisfies the air discharge fan and leaves and open the demand of closing along with being close of human body.

Drawings

Fig. 1 is a schematic front structural view of an embodiment of the present invention;

fig. 2 is a schematic view of each viewing area structure viewed from the bottom according to the embodiment of the present invention;

fig. 3 is a schematic view of a lens structure viewed from the bottom according to an embodiment of the present invention.

Wherein:

1. a central viewing zone; 2. a near vision zone; 3. the far vision zone.

Detailed Description

It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The present invention will be further explained with reference to the drawings and the embodiments.

The utility model discloses use the exhaust fan at bathroom top, the concrete condition of using does: the air discharge fan is installed in the bathroom top, openly downwards, and infrared detection device installs at the air discharge fan openly, the utility model discloses a lens body of lens structure openly downwards, highly 2.5 meters to 3 meters between, ambient temperature 25, human walking speed 1 meter per second.

As shown in fig. 1, the lens body of the lens structure provided by the present invention is hemispherical, with the front surface facing downward, and is divided into a central visual area 1, a near vision area 2 and a far vision area 3 for accurately grasping the area of the moving target; the concrete description is as follows:

the central visual area 1 only comprises a spherical convex circular lens, the lens is positioned at the central position of the spherical surface of the hemispherical crystal, and concentric circular grains with the central position as the center of a circle are arranged on the lens and focused on the sensing area of the pyroelectric sensor of the curtain detector; the central visual area 1 is used for capturing human body signals under the exhaust fan and in the surrounding area.

As shown in fig. 2, the near vision zone 2 is an annular spherical convex structure, and is evenly divided into 8 small zones around the central vision zone 1, and the small zones are all focused on the sensing area of the pyroelectric sensor of the curtain detector; every 2 small blocks are a group, as shown in fig. 3, the centers of the concentric circles of the fresnel patterns of two small blocks in a group are respectively and correspondingly arranged at the opposite corners where the two small blocks are butted, and the fresnel patterns of the two small blocks are correspondingly consistent and can be butted into a large fresnel pattern. The near vision zone 2 thus designed is advantageous for infrared detection of the peripheral zone just below the exhaust fan and in the surrounding area, where the trigger point is sufficient for signal capture.

As shown in fig. 2, the far vision zone 3 is an annular spherical convex structure, annularly surrounds the near vision zone 2, the far vision zone 3, the near vision zone 2 and the central vision zone 1 together form a hemispherical lens body, the far vision zone 3 corresponds to the near vision zone 2, and is also equally divided into 8 small blocks, and the small blocks are all focused on a sensing area of a pyroelectric sensor of the curtain detector; the circle center of the concentric circle of the Fresnel line of each small block is positioned on the upper part of the vertical central line of the Fresnel line. The far vision zone 3 thus designed facilitates infrared detection of more peripheral regions, the trigger point being sufficient for signal capture in more peripheral regions.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A lens structure for an exhaust fan is characterized by comprising a hemispherical lens body, wherein the lens body comprises a central visual area positioned in the center of the lens body, a near vision area annularly surrounding the central visual area, and a far vision area annularly surrounding the near vision area; the central visual area is a circular lens with a spherical bulge and is provided with Fresnel lines; the near vision zone and the far vision zone respectively comprise a plurality of small blocks, the small blocks are lens sheets provided with Fresnel lines, and each lens sheet is focused on a sensing area of the pyroelectric sensor in the exhaust fan.

2. The lens structure of claim 1 wherein the small blocks of the near vision zone are of uniform size and shape; the small blocks of the far vision area are consistent in size and shape.

3. A lens arrangement for an exhaust fan according to claim 1 or 2, wherein the number of the small zones of the near vision zone is one-to-one corresponding to the number of the small zones of the far vision zone.

4. The lens structure for an exhaust fan as claimed in claim 1, wherein the center of the concentric circles of the fresnel patterns of the central vision region is located at a central position of the lens sheet of the central vision region.

5. The lens structure of claim 1, wherein the small blocks of the near vision zone are in a group of 2, and the centers of the concentric circles of the fresnel patterns of two small blocks in a group are respectively and correspondingly arranged at the opposite corners of the butt joint of the two small blocks.

6. The lens structure of claim 1, wherein the centers of the concentric circles of the fresnel patterns of the small zones of the far vision region are located above the respective vertical center lines.