Optical detection device and system for simultaneously detecting end face and side face of cylinder

Abstract

The invention relates to an optical detection device and system for simultaneously detecting the end face and the side face of a cylinder. The optical detection device comprises a first lens and a second lens, wherein a light reflection region is arranged on the convex surface of the first lens; the outer periphery of the concave surface of the second lens is a light reflection area, and the inner periphery is a light transmission area; a lens and an optical sensor; the first lens is arranged between a to-be-measured end surface of a cylindrical measured object and the second lens, and the convex surface of the first lens faces the concave surface of the second lens; light reflected by the to-be-measured end face and the side face of a cylindrical measured object firstly enters the light reflection area of the concave face of the second lens, then is reflected to the light reflection area of the convex face of the first lens, and finally enters the lens through the light transmission area of the second lens; the lens shapes incident light and then makes the light irradiate the light-sensitive surface of the optical sensor, so that the optical sensor performs imaging to obtain a detection image including the to-be-detected end face and the side face of the cylindrical detected object.

Description

Technical Field

[0001] The present invention relates to the field of machine vision, and in particular to an optical detection device and system for simultaneously detecting the end face and side face of a cylinder. Background Art

[0002] Machine vision is a technology that uses machines to measure and judge products instead of the human eye. It uses optical sensors to capture product images, which are then processed and analyzed by a processor to obtain the required measurement data or judgment results. Existing machine vision systems typically require multiple lenses to simultaneously detect both the side and end faces of cylindrical products.

[0003] See also Figure 1 , Figure 1 The present invention is a schematic diagram of the structure and optical path of an existing multi-lens cylindrical optical detection device. The existing multi-lens cylindrical optical detection device includes: an end face detection lens 01, a first side face detection lens 02, and a second side face detection lens 03. The end face detection lens 01 faces the end face to be measured of the cylindrical object to be measured DUT, the first side face detection lens 02 faces the left side of the cylindrical object to be measured DUT, and the second side face detection lens 03 faces the right side of the cylindrical object to be measured DUT. If 360° imaging of the side of the cylindrical object to be measured DUT is to be achieved, in order to ensure that there is no detection blind spot at the intersection of the fields of view of the first side face detection lens 02 and the second side face detection lens 03, the device also needs to be provided with a third side face detection lens so that the imaging ranges of the three side face detection lenses on the side of the cylindrical object to be measured DUT overlap with each other. It can be seen that this multi-lens cylindrical optical inspection device requires at least four lenses to achieve full-range imaging of the end face and side face of the cylindrical object under test DUT at the same time. It has the defects of high cost, large space occupation and heavy weight. It is difficult to take into account engineering application requirements such as full-range high-precision imaging, equipment economy, space compactness and system lightweight.

[0004] See also Figure 2 , Figure 2The structure and optical path diagram of an existing lens-based cylindrical optical detection device. Chinese patent CN213544395U discloses a lens-based cylindrical optical detection device, which refracts light reflected from the end face and side faces of a cylindrical object under test (DUT) through an optical path adjustment mechanism 04 composed of four lenses. This allows the lens and optical sensor disposed at the rear end of the optical path adjustment mechanism 04 to simultaneously receive light reflected from the end face and side faces of the cylindrical object under test (DUT). Although this lens-based cylindrical optical detection device can simultaneously detect the end face and side faces of a cylindrical object under test (DUT) using a single lens, it requires a large number of lenses, resulting in a heavy weight and large volume. Furthermore, all of the lenses are fixed in a lens barrel, resulting in poor adjustability and low flexibility. Summary of the Invention

[0005] Based on this, an object of the present invention is to provide an optical detection device and system for simultaneously detecting the end face and side face of a cylinder.

[0006] The present invention provides an optical detection device for simultaneously detecting the end face and side face of a cylinder, comprising: a first lens, which is a curved lens with a convex surface, and a light reflection area is provided on the convex surface of the first lens; a second lens, which is a curved lens with a concave surface, and the outer periphery of the concave surface is a light reflection area, and the inner periphery is a light transmission area; a lens and an optical sensor; the first lens is arranged between the end face to be measured of the cylindrical object to be measured and the second lens, with the convex surface of the first lens facing the concave surface of the second lens; the light reflected by the end face to be measured and the side face of the cylindrical object to be measured first enters the light reflection area of the concave surface of the second lens, and then is reflected to the light reflection area of the convex surface of the first lens, and finally enters the lens through the light transmission area of the second lens; the lens shapes the incident light and then irradiates the light to the photosensitive surface of the optical sensor, so that the optical sensor images and obtains a detection image including the end face to be measured and the side face of the cylindrical object to be measured.

[0007] The present invention uses a first lens and a second lens to adjust the optical path of light reflected from the end and side faces of a cylindrical object under test, enabling simultaneous inspection of both ends and sides of the object using a single lens. Compared to existing multi-lens cylindrical product inspection devices, this invention significantly reduces the number of lenses, lowering costs, saving space, and reducing equipment weight. It balances engineering application requirements such as omnidirectional imaging accuracy, equipment cost-effectiveness, compactness, and system lightweighting.

[0008] Furthermore, the convex surface of the first lens is a convex spherical surface, an external convex hyperboloid or an external convex paraboloid; and the concave surface of the second lens is a concave spherical surface, an internal concave hyperboloid or an internal concave paraboloid.

[0009] Furthermore, a line connecting the center of the end face to be measured of the cylindrical object to be measured and the edge of the first lens passes through the light reflection area of the concave surface of the second lens.

[0010] Furthermore, the geometric centers of the first lens and the second lens are both arranged on the axis of the cylindrical object to be measured, and their shapes are rotationally symmetrical along the axis of the cylindrical object to be measured.

[0011] Furthermore, the light reflection area is plated with a reflection film; and the light transmission area is hollow or transparent.

[0012] Furthermore, the light transmission area is transparent and coated with an anti-reflection film.

[0013] Furthermore, the first lens and the second lens are fixedly connected via a connecting bridge so that the relative distance between them can be adjusted.

[0014] Furthermore, a mounting hole is provided at the geometric center of the first lens or the second lens; the first end of the connecting bridge is fixed at the geometric center of the second lens or the first lens, and the second end is inserted into the mounting hole of the first lens or the second lens.

[0015] Furthermore, it also includes: a guide rail, a first lens fixing seat, a second lens fixing seat and a receiving end fixing seat; the first lens fixing seat, the second lens fixing seat and the receiving end fixing seat can all be slidably set on the guide rail; the first lens is mounted on the first lens fixing seat; the second lens is mounted on the second lens fixing seat; the lens and the optical sensor are mounted on the receiving end fixing seat; by slidingly adjusting the positions of the first lens fixing seat, the second lens fixing seat and the receiving end fixing seat on the guide rail, the positions of the first lens, the second lens, the lens and the optical sensor can be adjusted.

[0016] Based on the same inventive concept, the present invention also provides a cylindrical optical detection system, which includes: any one of the above-mentioned optical detection devices and a processor for simultaneously detecting the end face and side face of the cylinder; the optical sensor of the optical detection device transmits the detection image to the processor; the processor processes and analyzes the detection image to obtain the detection result.

[0017] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The figure is a schematic diagram of the structure and optical path of an existing multi-lens cylindrical optical detection device; Figure 2 The figure is a schematic diagram of the structure and optical path of an existing lens-based cylindrical optical detection device; Figure 3Schematic diagram of a module of a cylindrical optical detection system according to the present invention; Figure 4 Schematic diagram of the structure and optical path of the optical detection device for simultaneously detecting the end face and side face of a cylinder according to the present invention; Figure 5 FIG1 is a schematic diagram of partitions of the concave surface of the second lens viewed from the axial direction of a cylindrical object to be measured in one embodiment of the present invention; Figure 6 This is a schematic diagram of the effect of the detection image taken by the optical detection device for simultaneously detecting the end face and side face of a cylinder according to the present invention.

[0019] Reference numerals: cylindrical object under test DUT; optical path adjustment mechanism 10 ; first lens 11 ; second lens 12 ; outer periphery 121 ; inner periphery 122 ; mounting hole 123 ; connecting bridge 13 ; lens 20 ; optical sensor 30 . DETAILED DESCRIPTION

[0020] This invention addresses the shortcomings of existing multi-lens cylindrical optical inspection devices and redesigns a completely different optical inspection device, capable of simultaneously inspecting both the end and side faces of a cylinder. This device replaces the optical path adjustment mechanism 04, which consists of multiple lenses in existing lens-based cylindrical optical inspection devices, with an optical path adjustment mechanism composed of reflectors. This not only reduces the number and weight of lenses but also offers excellent adjustability, adapting to a variety of cylindrical inspection scenarios.

[0021] See also Figure 3 , Figure 3 The figure is a block diagram of the cylindrical optical inspection system of the present invention. The cylindrical optical inspection system of the present invention comprises an optical inspection device A and a processor B. The optical inspection device A is the optical inspection device of the present invention for simultaneously inspecting both the end face and side face of a cylindrical object under test (DUT). The optical inspection device A is configured to capture inspection images of both the end face and side face of the cylindrical object under test (DUT) and transmit the inspection images to the processor B. The processor B is signal-connected to the optical inspection device A and processes and analyzes the inspection images to obtain the inspection results required for machine vision inspection.

[0022] In one embodiment, the processor B can restore the detection image into an end face image and a side face image using a mapping transformation algorithm, and then identify stains or defects on the end face image and the side face image using an object detection algorithm, thereby obtaining a detection result of whether stains or defects exist on the end face and side face of the cylindrical object under test (DUT). Those skilled in the art can determine the processing and analysis algorithm executed by the processor B as needed, and the present invention does not specifically limit this.

[0023] See also Figure 4 , Figure 4 The structure and optical path diagram of the optical detection device for simultaneously detecting the end face and side face of a cylinder of the present invention. The optical detection device for simultaneously detecting the end face and side face of a cylinder of the present invention comprises an optical path adjustment mechanism 10, a lens 20, and an optical sensor 30. The light reflected by the end face and side face to be measured of the cylindrical object under test DUT is irradiated to the lens 20 after the optical path is adjusted by the optical path adjustment mechanism 10. The lens 20 shapes the incident light and then irradiates the shaped light to the photosensitive surface of the optical sensor 30 disposed behind the lens 20, so that the optical sensor 30 forms an image to obtain a detection image including the end face and side face to be measured of the cylindrical object under test DUT.

[0024] Specifically, the optical path adjustment device 10 includes: a first lens 11 and a second lens 12, which are sequentially arranged on the axis of the cylindrical object under test (DUT). The geometric centers of the first lens 11 and the second lens 12 are both arranged on the axis of the cylindrical object under test (DUT), and their shapes are rotationally symmetric along the axis of the cylindrical object under test (DUT).

[0025] The first lens 11 is close to the cylindrical object under test DUT. The side of the first lens 11 close to the second lens 12 is a convex surface; a light reflection area is provided on the convex surface. The "side of the first lens close to the second lens is a convex surface" specifically means that the horizontal distance between the center of the side of the first lens 11 close to the second lens 12 and a reference point on the second lens 12 is less than the horizontal distance between the edge of the side of the first lens 11 and the same reference point, so that Figure 4 The side of the first lens 11 closest to the second lens 12 appears to be convex toward the second lens 12. The convex surface of the first lens 11 can be a convex surface formed by splicing together several planes, or can be a convex spherical surface, an outwardly convex hyperboloid, or an outwardly convex paraboloid. Preferably, the convex surface of the first lens 11 is an outwardly convex paraboloid.

[0026] The size of the second lens 12 is larger than that of the first lens 11; the side of the second lens 12 close to the first lens 11 is a concave surface; the outer periphery 121 of the concave surface is a light reflection area, and the inner periphery 122 is a light transmission area; the line connecting the center of the end face to be measured of the cylindrical object to be measured and the edge of the first lens 11 passes through the light reflection area 121 of the concave surface of the second lens 12. Among them, "the side of the second lens 12 close to the first lens 11 is a concave surface" specifically means that the horizontal distance from the center of the side of the second lens 12 close to the first lens 11 to a reference point on the first lens 11 is greater than the horizontal distance from the edge of this side to the same reference point, so that Figure 4The surface of the second lens 12 closest to the first lens 11 appears concave relative to the first lens 11. The concave surface of the second lens 12 can be a concave surface formed by splicing together several planes, or can be a concave spherical surface, an inwardly concave hyperboloid, or an inwardly concave paraboloid. Preferably, the concave surface of the second lens 12 is an inwardly concave paraboloid.

[0027] The light-reflecting area on the convex surface of the first lens 11 and the light-reflecting area on the outer periphery 121 of the concave surface of the second lens 12 are coated with a reflective film, so that when light hits the light-reflecting area, the light's optical path changes according to the law of reflection. The light-transmitting area on the inner periphery 122 of the second lens 12 is hollowed out or transparent, allowing light to pass directly through the light-transmitting area while maintaining the optical path unchanged. Preferably, the light-transmitting area 122 is transparent and coated with an anti-reflection film.

[0028] Furthermore, the first lens 11 and the second lens 12 are fixedly connected via a connecting bridge 13 so that their relative distance can be adjusted. Specifically, a mounting hole is provided at the geometric center of the first lens 11 or the second lens 12; the first end of the connecting bridge 13 is fixed to the geometric center of the second lens 12 or the first lens 11, and the second end is inserted into the mounting hole of the first lens 11 or the second lens 12; the relative distance between the first lens 11 and the second lens 12 can be adjusted by adjusting the depth of the second end of the connecting bridge 13 inserted into the mounting hole.

[0029] In this embodiment, a mounting hole 123 is provided at the geometric center of the second lens 12; the first end of the connecting bridge 13 is fixed to the geometric center of the first lens 11, and the second end is inserted into the mounting hole 123 of the second lens 12. Figure 5 , Figure 5 Schematic diagram of the partitioning of the concave surface of the second lens viewed from the axial direction of the cylindrical object to be measured in the present invention. Figure 5 The dark shaded area is the outer peripheral area 121 coated with a reflective film, the light shaded area is the transparent inner peripheral area 122 coated with an anti-reflection film, and the white area is the mounting hole 123 for mounting the connecting bridge.

[0030] Specifically, the lens 20 is a cylindrical lens, with a first end receiving light whose path has been adjusted by the optical path adjustment mechanism 10, and a second end facing the photosensitive surface of the light sensor 30. The relative positions of the lens 20 and the optical sensor 30 are fixed. In one embodiment, the relative positions of the lens 20 and the optical sensor 30 can be fixed using a fixture such as a lens barrel. The present invention does not specifically limit the method for fixing the lens 20 and the optical sensor 30.

[0031] The working principle of the present invention for simultaneously detecting the end face and side face of a cylindrical object under test DUT is as follows: Figure 4In the optical path shown, the light reflected by the end face and side face of the cylindrical object under test DUT is first irradiated to the light reflection area 121 of the concave surface of the second lens 12, and then reflected to the light reflection area of the convex surface of the first lens 11; the light reflection area of the convex surface of the first lens 11 then reflects the light to the light transmission area 122 of the concave surface of the second lens 12, so that the light passes through the light transmission area 122 and enters the lens 20. The lens 20 shapes the incident light and makes the shaped light irradiate the photosensitive surface of the optical sensor 30, so that the optical sensor 30 captures a detection image including the end face and side face of the cylindrical object under test DUT. The effect of the detection image captured by the optical sensor 30 is as follows: Figure 6 As shown, the inner periphery of the detection image shows the end face to be tested of the cylindrical object under test DUT, and the outer periphery shows all side faces of the cylindrical object under test DUT.

[0032] Furthermore, in order to prevent the connecting bridge 13 from loosening after being inserted into the mounting hole, causing the relative positions of the first lens 11 and the second lens 12 to be unstable and causing unexpected deformation of the detection image, the second end of the connecting bridge 13 is fixed to the mounting hole by snapping or threading. In a threaded fixation embodiment, a hollow sleeve is further provided on the mounting hole; an internal thread is provided on the surface of the sleeve; and an external thread that cooperates with the internal thread of the sleeve is provided on the connecting bridge 13. When the user inserts the connecting bridge 13 into the mounting hole, the user can control the depth of the second end of the connecting bridge 13 inserted into the mounting hole by rotating the connecting bridge 13, thereby adjusting the relative distance between the first lens 11 and the second lens 12. When not adjusted, the connecting bridge 13 is not easy to loosen because the internal thread of the sleeve is fixed with the external thread of the connecting bridge 13.

[0033] Furthermore, in order to ensure that the geometric centers of the first lens 11, the second lens 12, the lens 20, and the optical sensor 30 are all located on the axis of the cylindrical object under test (DUT), and to facilitate adjustment of the relative distances between the cylindrical object under test (DUT), the first lens 11, the second lens 12, the lens 20, and the optical sensor 30, the optical detection device of the present invention further includes: a guide rail, a first lens holder, a second lens holder, and a receiving end holder. The first lens holder, the second lens holder, and the receiving end holder are slidably disposed on the guide rail in sequence, the first lens 11 is mounted on the first lens holder, the second lens 12 is mounted on the second lens holder, and the lens 20 and the optical sensor 30 are mounted on the receiving end holder. By slidingly adjusting the positions of the first lens holder, the second lens holder, and the receiving end holder on the guide rail, the relative distances between the cylindrical object under test (DUT), the first lens 11, the second lens 12, the lens 20, and the optical sensor 30 can be adjusted to ensure that the detection image captured by the optical sensor 30 is ideal. Since sliding the first lens fixing seat and the second lens fixing seat can adjust the relative distance between the first lens 11 and the second lens 12, in the embodiment using the guide rail, the first lens fixing seat and the second lens fixing seat, the first lens 11 and the second lens 12 may not be fixedly connected by the connecting bridge 13.

[0034] For the size of the first lens 11 and the curvature of its convex surface, the size of the second lens 12 and the curvature of its concave surface, the distance between the geometric centers of the first lens 11 and the second lens 12, the distance between the first lens 11 and the end face to be measured of the cylindrical object to be measured DUT, the distance between the second lens 12 and the lens 20, and the ratio of the radii of the outer periphery and the inner periphery of the concave surface of the second lens 12, those skilled in the art can adaptively select the specific values of the above parameters by observing the effect of the detection image, and the present invention does not make specific limitations.

[0035] The present invention has the following technical effects: the lens 20 is set on the axis of the cylindrical object under test DUT, and originally can only receive the light reflected by one end face of the cylindrical object under test DUT, but the present invention sets an optical path adjustment mechanism 10 composed of a first lens 11 and a second lens 12, so that the light reflected by the side face of the cylindrical object under test DUT can also enter the lens 20 after the optical path adjustment, thereby realizing the simultaneous detection of the end face and side face of the cylindrical object under test DUT through a single lens. Compared with the cylindrical product detection device with multiple lenses in the prior art, the present invention greatly reduces the number of lenses, reduces costs, saves space, and reduces the weight of the equipment, taking into account engineering application requirements such as all-round imaging accuracy, equipment economy, space compactness and system lightweighting. Compared with the existing lens-based cylindrical optical detection device, the present invention reduces the number of lenses and the weight of the device, improves the flexibility of adjustment, and can adapt to various different cylindrical detection scenarios.

[0036] The above-described embodiments merely represent several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous modifications and improvements without departing from the spirit of the present invention, and the present invention is intended to encompass such modifications and variations.

Claims

1. An optical detection device for simultaneously detecting the end face and side face of a cylinder, characterized in that: include: The first lens is a curved lens with a convex surface, and a light reflection area is provided on the convex surface; The second lens is a curved lens with a concave surface, wherein the outer periphery of the concave surface is a light reflection area and the inner periphery is a light transmission area; lenses and optical sensors; The first lens is arranged between the end face to be measured of the cylindrical object to be measured and the second lens, and the convex surface of the first lens faces the concave surface of the second lens; The light reflected by the end face and side face to be measured of the cylindrical object to be measured first enters the light reflection area of the concave surface of the second lens, is then reflected to the light reflection area of the convex surface of the first lens, and finally enters the lens through the light transmission area of the second lens; the lens shapes the incident light and then allows the light to be irradiated to the photosensitive surface of the optical sensor, so that the optical sensor images and obtains a detection image including the end face and side face to be measured of the cylindrical object to be measured.

2. The optical detection device for simultaneously detecting the end face and side face of a cylinder according to claim 1, characterized in that: The convex surface of the first lens is a convex spherical surface, an outward convex hyperbolic surface or an outward convex paraboloid; The concave surface of the second lens is a concave spherical surface, an inwardly concave hyperbolic surface or an inwardly concave paraboloid surface.

3. The optical detection device for simultaneously detecting the end face and side face of a cylinder according to claim 2, characterized in that: A line connecting the center of the end face to be measured of the cylindrical measured object and the edge of the first lens passes through the light reflection area of the concave surface of the second lens.

4. The optical detection device for simultaneously detecting the end face and side face of a cylinder according to claim 3, characterized in that: The geometric centers of the first lens and the second lens are both arranged on the axis of the cylindrical object to be measured, and their shapes are rotationally symmetrical along the axis of the cylindrical object to be measured.

5. The optical detection device for simultaneously detecting the end face and side face of a cylinder according to claim 4, characterized in that: The light reflection area is plated with a reflective film; The light transmission area is hollow or transparent.

6. The optical detection device for simultaneously detecting the end face and side face of a cylinder according to claim 5, characterized in that: The light transmission area is transparent and coated with an anti-reflection film.

7. The optical detection device for simultaneously detecting the end face and side face of a cylinder according to claim 6, characterized in that: The first lens and the second lens are fixedly connected via a connecting bridge so that the relative distance between them can be adjusted.

8. The optical detection device for simultaneously detecting the end face and side face of a cylinder according to claim 7, characterized in that: A mounting hole is provided at the geometric center of the first lens or the second lens; The first end of the connecting bridge is fixed to the geometric center of the second lens or the first lens, and the second end is inserted into the mounting hole of the first lens or the second lens.

9. The optical inspection device for simultaneously inspecting the end face and side face of a cylinder according to claim 1, characterized in that: Also includes: A guide rail, a first lens fixing seat, a second lens fixing seat and a receiving end fixing seat; The first lens fixing seat, the second lens fixing seat and the receiving end fixing seat can all be slidably arranged on the guide rail; The first lens is mounted on the first lens fixing seat; The second lens is mounted on the second lens fixing seat; The lens and optical sensor are mounted on the receiving end fixing seat; The positions of the first lens, the second lens, the lens and the optical sensor can be adjusted by slidingly adjusting the positions of the first lens fixing seat, the second lens fixing seat and the receiving end fixing seat on the guide rail.

10. A cylindrical optical detection system, characterized in that: include: The optical detection device and processor for simultaneously detecting the end face and side face of a cylinder according to any one of claims 1 to 9; The optical sensor of the optical detection device transmits the detection image to the processor; The processor processes and analyzes the detection image to obtain a detection result.

Images