CN212111834U - Opposite light curtain - Google Patents

Abstract

The utility model discloses a correlation light curtain. The transmitter comprises a first linear convex lens and a plurality of transmitting tubes, wherein the overall shape of the transmitting tubes is a long strip shape, the transmitting tubes are arranged one by one along the length direction of the first linear convex lens, the light emitting surfaces of the transmitting tubes are located on the focus of the first linear convex lens, the receiver comprises a second linear convex lens and a plurality of receiving tubes, the overall shape of the receiving tubes is a long strip shape, the receiving tubes are arranged one by one along the length direction of the second linear convex lens, and the light receiving surfaces of the receiving tubes are located on the focus of the second linear convex lens. The utility model discloses utilize the focus of linear type convex lens to be this structural feature of straight line, can make a slice convex lens can supply a plurality of transmitting tubes or a plurality of receiver tube used jointly simultaneously, not only can reduce the light curtain to constitute the use quantity of spare part effectively, reduce the structural complexity of light curtain, the manufacturing cost and the equipment degree of difficulty, can improve the ability that the correlation light curtain detected little volume object through the mode that increases the mounting density of transmitting tube and receiver tube moreover.

Description

Opposite light curtain

Technical Field

The utility model belongs to the technical field of the industry detects technique and specifically relates to a correlation light curtain.

Background

As is known, the opposite light curtain is an industrial detection device that uses a transmitter to continuously transmit a probe light beam (such as infrared ray) so that the probe light beam can form a light curtain between the transmitter and a receiver, and when the light curtain is blocked or partially blocked, a control main body can determine whether an object invades a light curtain area according to the receiving state of the receiver to the probe light beam and make a corresponding reaction; the device is widely applied to the industrial production field, such as detecting whether a human body enters or a limb extends into a dangerous area, detecting whether a workpiece on a conveying device is replaced to a preset position, measuring the overall dimension of an object and the like.

When the correlation light curtain is applied to scenes with a large detection range (namely, the distance between a transmitter and a receiver is long), a convex lens is often required to be arranged in front of a transmitting tube of the transmitter or in front of a receiving tube of the receiver; for the emitter, the convex lens can reduce the divergence angle of the detection light beam, so that the detection light beam is close to parallel light as much as possible, and the phenomenon of light intensity reduction caused by distance increase is reduced; for the receiver, the convex lens can increase the light receiving area for receiving the detection light beam, enhance the light intensity of the detection light beam received by the receiving tube and irradiated from the front, and weaken the intensity of the ambient light irradiated into the receiving tube from the side, so that the anti-ambient light interference capability of the receiver is enhanced.

In view of the above requirements, the existing alignment light curtain is usually configured with a single spherical convex lens with a circular or approximately circular overall shape for each transmitting tube or each receiving tube, so as to form a transmitter or a receiver similar to the alignment light curtain shown in fig. 1; the advantages of this arrangement are: the accurate alignment between the optical axis of the convex lens and the light emitting surface of the transmitting tube or the light receiving surface of the receiving tube can be easily realized, and the detection distance of the correlation light curtain is enlarged to the maximum extent. However, the disadvantages of this arrangement are also apparent, namely: the transmitter is mainly composed of a plurality of transmitting tubes arranged in rows, and the receiving tubes of the receiver are in one-to-one correspondence with the transmitting tubes; in the case of configuring a separate convex lens for each transmitting tube and/or each receiving tube, not only a considerable number of convex lenses need to be used, but also a complex and numerous lens holder has to be mounted inside the light curtain in order to fix the convex lenses; thus, the manufacturing cost, assembly difficulty, and housing volume of the transmitter and receiver of the light curtain are greatly increased. Meanwhile, in order to avoid the position conflict of the convex lenses between two adjacent transmitting tubes or two receiving tubes, the installation density of the transmitting tubes or the receiving tubes has to be limited, so that the detection capability of the incident light curtain for small-volume articles is seriously weakened.

SUMMERY OF THE UTILITY MODEL

To the not enough of above-mentioned prior art existence, the utility model aims to provide a correlation light curtain.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a correlation light curtain comprises a transmitter and a receiver, wherein the transmitter comprises a plurality of transmitting tubes distributed in rows, the receiver comprises a plurality of receiving tubes distributed in rows, and the transmitting tubes and the receiving tubes are the same in number and are in one-to-one correspondence;

the emitter also comprises a first linear convex lens which is in a long strip shape as a whole, the plurality of emission tubes are arranged one by one along the length direction of the first linear convex lens, and the light emitting surfaces of all the emission tubes are positioned on the focus of the first linear convex lens;

and/or

The receiver also comprises a second linear convex lens which is in a long strip shape in the whole shape, the plurality of receiving tubes are arranged one by one along the length direction of the second linear convex lens, and the light receiving surfaces of all the receiving tubes are positioned on the focus of the second linear convex lens.

Preferably, the first linear convex lens and/or the second linear convex lens is one of a biconvex lens, a plano-convex lens and a fresnel lens, and the overall shape of the biconvex lens is elongated.

Due to the adoption of the scheme, the utility model discloses utilize this structural feature that the focus of linear type convex lens is the straight line, can make a slice convex lens can supply a plurality of transmitting tubes or a plurality of receiving tubes to use jointly simultaneously, not only can reduce the use quantity of light curtain component part effectively, reduce the structural complexity, manufacturing cost and the equipment degree of difficulty of light curtain, can improve the ability that the correlation light curtain detected small volume object through the mode that increases the installation density of transmitting tube and receiving tube moreover; the structure is simple, the assembly is convenient, the manufacturing cost is low, and the practical value and the market promotion value are very strong.

Drawings

FIG. 1 is a schematic diagram of a convex lens structure of a transmitter or a receiver of a prior art opposite-light curtain;

fig. 2 is a schematic cross-sectional light path diagram of an embodiment of the present invention when a linear lenticular lens is used;

fig. 3 is a schematic cross-sectional light path diagram of the embodiment of the present invention when a linear plano-convex lens is used;

fig. 4 is a schematic cross-sectional light path diagram of the embodiment of the present invention when a linear fresnel lens is used;

fig. 5 is a schematic structural reference view of a linear lenticular lens according to an embodiment of the present invention;

fig. 6 is a schematic structural reference view of a linear plano-convex lens according to an embodiment of the present invention;

fig. 7 is a schematic structural reference diagram of a linear fresnel lens according to an embodiment of the present invention.

Detailed Description

The embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways as defined and covered by the claims.

Example 1

As shown in fig. 2 to 7, the opposite light curtain provided by this embodiment includes an emitter 10 and a receiver 20, wherein the emitter 10 includes a first linear convex lens 11 with an overall shape of a long strip, and a plurality of emission tubes 12 which are arranged one by one along a length direction of the first linear convex lens 11 and have light-emitting surfaces located at a focus of the first linear convex lens 11; the receiver 20 includes a second linear convex lens 21 with an overall shape of a long strip, and a plurality of receiving tubes 22 which are arranged one by one along the length direction of the second linear convex lens 21 and have light receiving surfaces located at the focus of the second linear convex lens 21, and the number of the transmitting tubes 12 is the same as that of the receiving tubes 22, and the transmitting tubes 12 correspond to the receiving tubes 22 one by one. It should be noted that: the "linear convex lens" mentioned in the present embodiment may be understood as a strip-shaped plate-shaped structure whose sectional shape is constant (or consistent) in the length direction, and the focal point of the structure is a straight line, which is different from the structure that the focal point of the conventional convex lens is a single point.

Therefore, based on the structural characteristic that the focal points of the linear convex lenses are linear, after the plurality of transmitting tubes 12 are arranged along the length direction of the first linear convex lens 11 and the straight lines (or planes) where the light emitting surfaces of all the transmitting tubes 12 are located are ensured to be superposed with the straight lines where the focal points of the first linear convex lens 11 are located, all the transmitting tubes 12 can share one first linear convex lens 11, and similarly, all the receiving tubes 22 share one second linear convex lens 21; thus, when the transmitter 10 and the receiver 20 are assembled by using the linear convex lens, since there is no problem that the linear convex lens needs to be aligned with the optical axis of each transmitting tube 12 or each receiving tube 22 one by one, there is no need to configure the convex lens and the associated lens fixing bracket for each transmitting tube 12 and each receiving tube 22 one by one, and only the linear convex lens needs to be directly installed and fixed, which not only can effectively reduce the number of components, reduce the structural complexity of the whole light curtain, the manufacturing cost of the light curtain and the assembling difficulty; and the problem that mutual conflict of occupied positions of lenses is easily caused by adopting the traditional convex lens does not occur between the adjacent transmitting tubes 12 or between the adjacent receiving tubes 22, so that the capability of detecting small-volume objects by the light curtain can be improved by increasing the mounting density of the transmitting tubes 12 and the receiving tubes 22.

In the present embodiment, the first linear convex lens 11 and the second linear convex lens 12 may be any one of a biconvex lens (as shown in fig. 2 and 5), a plano-convex lens (as shown in fig. 3 and 6), and a fresnel lens (as shown in fig. 4 and 7) with an elongated overall shape according to the actual design and application of the light curtain. As a preferred embodiment, the first linear convex lens 11 and the second linear convex lens 12 are preferably fresnel lenses, so as to utilize the characteristics of the fresnel lenses, such as the most material saving, the thinnest thickness of the lenses, the good light transmittance, the small occupied space, and the like, to reduce the manufacturing cost of the whole light curtain, reduce the volume of the light curtain product, and create good conditions for miniaturization and low cost of the light curtain product.

Example 2

The structure form and the model selection mode of the lens are basically the same as those of the embodiment 1, and the difference is that: the first rectilinear convex lenses 11 are arranged only for all the transmitting tubes 12 or the second rectilinear convex lenses 21 are arranged only for all the receiving tubes 22.

In order to more clearly illustrate the features of the present invention and provide a practical reference idea for the practical design or application thereof, as shown in fig. 2 to 4, a slot for the linear convex lens to be mounted in a clamping manner may be provided in the housing a of the transmitter 10 and/or the receiver 20, so that the linear convex lens can cover the control board b integrated with the plurality of transmitting tubes 12 and/or the receiving tubes 22; when the probe beam is emitted by the emission tube 12 and passes through the first linear convex lens 11, the probe beam is expanded into a parallel beam (the light divergence angle is greatly reduced), so that the light intensity of the probe beam is favorably not greatly reduced due to excessive divergence after long-distance transmission; after passing through the second linear convex lens 21, the probe beam is focused again and finally received by the receiving tube 22 whose light receiving surface is located at the focal point of the second linear convex lens 21. Therefore, the convex lens can be directly installed by directly optimizing the structure of the shell a, so that the light curtain structure is more convenient to assemble, and the miniaturization of a light curtain product is very convenient to realize; meanwhile, the convex lens and the baffle of the light transmission window of the shell a can be combined into a whole if necessary (namely, the convex lens is used for directly replacing the baffle of the light transmission window), and the volume of the product can be further reduced.

The above only is the preferred embodiment of the present invention, not limiting the scope of the present invention, all the equivalent structures or equivalent flow changes made by the contents of the specification and the drawings, or directly or indirectly applied to other related technical fields, are included in the same way in the protection scope of the present invention.

Claims (2)

1. A correlation light curtain comprises a transmitter and a receiver, wherein the transmitter comprises a plurality of transmitting tubes distributed in rows, the receiver comprises a plurality of receiving tubes distributed in rows, and the transmitting tubes and the receiving tubes are the same in number and are in one-to-one correspondence; the method is characterized in that:

the emitter also comprises a first linear convex lens which is in a long strip shape as a whole, the plurality of emission tubes are arranged one by one along the length direction of the first linear convex lens, and the light emitting surfaces of all the emission tubes are positioned on the focus of the first linear convex lens;

and/or

The receiver also comprises a second linear convex lens which is in a long strip shape in the whole shape, the plurality of receiving tubes are arranged one by one along the length direction of the second linear convex lens, and the light receiving surfaces of all the receiving tubes are positioned on the focus of the second linear convex lens.

2. An opposed light curtain as claimed in claim 1, wherein: the first linear convex lens and/or the second linear convex lens is one of a biconvex lens, a plano-convex lens and a Fresnel lens which are in a strip shape as a whole.

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