The same frequency confocal LED light source structure for three-dimensional defect detection on product surface

Abstract

The invention discloses a same-frequency confocal LED illumination light source structure for three-dimensional defect detection on product surfaces. The structure has high reliability in fixing with a lens assembly, is convenient for adjusting the illumination focal length of the LED illumination light source, and can instantly light up LED lamp beads, which can be overloaded and significantly improve brightness. The structure can be synchronously lit up in sequence with pixels of a linear CCD sensor, greatly saving energy consumption and extending service life while meeting lighting needs. The structure can realize the confocal working process through optics, greatly improve the accuracy of product surface (especially textile) detection sampling, and provide accurate raw data for subsequent image processing analysis, so as to cooperate with the use of CCD sensor sampling. The structure is convenient to control, does not need to match a heat dissipation unit, and can instantly light up LED lamp beads, which can be overloaded and light up without affecting service life. The heat dissipation needs can be met through an aluminum circuit substrate. The structure has a clever design and a novel concept, and has a good application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of product surfaces, and in particular to a same-frequency confocal LED light source structure for three-dimensional defect detection on product surfaces. Background Art

[0002] CCD sensors are made of a highly sensitive semiconductor material that can convert light into electric charges, which are then converted into digital signals through analog-to-digital converters for computer processing. Currently, CCD sensors are widely used in the detection of surface defects on industrial products, especially for the detection of various defects on the surface of products.

[0003] In the process of detecting product surface defects (which require very high accuracy), the sampling environment is very important. It is necessary to provide reliable and high-precision data for the subsequent image processing process in order to obtain accurate defect detection results.

[0004] According to the different types of product surface defects, they can be divided into three-dimensional defects and two-dimensional defects. Among them, three-dimensional defects include three-dimensional defects such as protrusions and depressions on the product surface, and defects presented in three-dimensional space. In the prior art, in the process of detecting three-dimensional defects on the product surface, the sampling environment is very important, because a parallel light source (obliquely irradiated on the three-dimensional defects) is required to present them. Therefore, the sampling lighting requirements for three-dimensional defects are much higher than those for two-dimensional defects. For three-dimensional defects on the product surface, if the sampling data is inaccurate, no matter how high the accuracy of the subsequent image processing method is, accurate three-dimensional defect detection on the product surface cannot be obtained.

[0005] At present, during the CCD sensor scanning and sampling process, the brightness and stability of the lighting source directly affect the dynamic range and accuracy of the CCD sensor scanning and sampling. The higher the brightness and better the stability of the lighting source, the more accurate the sampling data, the wider the dynamic range, and the more sample types can be obtained. At present, most lighting sources are LED lighting sources, and the improvement of lighting brightness is greatly limited by the heat dissipation capacity of LED lighting sources. For the surface inspection equipment of products at work, the installation space of the lighting source is limited, and it is often difficult to use LED lighting sources that are too large and heavy. Moreover, the shaking caused by the operation of the equipment will affect the stability of the lighting, thereby affecting the dynamic range and accuracy of the CCD sensor scanning and sampling.

[0006] Therefore, how to construct a same-frequency confocal LED light source structure for three-dimensional defect detection on the product surface based on the working characteristics of CCD sensor scanning sampling, which can reduce its volume and ensure its good and stable operation, so as to improve the accuracy of CCD sensor scanning sampling, is a problem that needs to be solved at present. Summary of the invention

[0007] The purpose of the present invention is to overcome the problem that the illumination light source is not bright enough and the heat dissipation is not good during the scanning sampling process of the existing CCD sensor. The same-frequency confocal LED light source structure for three-dimensional defect detection on the product surface of the present invention has high reliability in fixing with the lens assembly, and is convenient for adjusting the illumination focal length of the LED illumination light source, and instantly lighting up the LED lamp beads, which can be overloaded, and the brightness is significantly improved, and the pixels of the linear array CCD sensor are synchronously lit in sequence, while meeting the lighting needs, greatly saving energy consumption and extending the life, and according to the attribute characteristics of the three-dimensional defects on the product surface, the same-frequency confocal LED illumination light source is selected for illumination, which is convenient for the projection imaging detection of three-dimensional defects (including three-dimensional surface defects such as protrusions and depressions), has high overall stability, greatly improves the accuracy of three-dimensional defect detection sampling on the product surface, and has good application prospects.

[0008] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is:

[0009] A same-frequency confocal LED light source structure for three-dimensional defect detection on a product surface comprises a sampling lens assembly, an LED lighting source assembly and an adjustable lighting position bracket.

[0010] The LED lighting source assembly is installed at the rear end of the sampling lens assembly through an adjustable lighting position bracket.

[0011] The LED lighting source assembly is a same-frequency confocal LED lighting source, and the LED lighting beads inside can be controlled to light up or extinguish at a single point, and are evenly divided into a plurality of partitioned LED lamp bead units according to the position sequence. The partitioned LED lamp bead units are sequentially lit or extinguished according to the clock frequency at which the pixel points of the linear array CCD sensor are sequentially exposed along the working direction, so that the LED lighting source assembly and the linear array CCD sensor complete the same-frequency synchronous work;

[0012] The LED lighting source assembly can adjust the position of the LED lighting source assembly in the left and right directions through an adjustable lighting position bracket, so that the lighting focus point of the LED lamp beads inside and the sampling focus point of the pixel points of the linear array CCD sensor are located at the same position, thereby realizing confocal work.

[0013] The same-frequency confocal LED light source structure for the aforementioned three-dimensional defect detection on the product surface, the LED lighting source assembly includes an aluminum circuit substrate, an LED lamp bead strip is arranged in the middle of the aluminum circuit substrate, and the LED lamp bead strip has multiple LED lamp beads distributed in sequence at equal intervals, an anode power supply terminal row is arranged on the aluminum circuit substrate on one side of the LED lamp bead strip, and a cathode power supply terminal row is arranged on the aluminum circuit substrate on the other side of the LED lamp bead strip, the anode power supply terminal row is arranged on the opposite side of the cathode power supply terminal row, the positive poles of each LED lamp bead in the LED lamp bead strip are respectively connected to the terminals of the anode power supply terminal row in sequence, and the negative poles of each LED lamp bead in the LED lamp bead strip are respectively connected to the terminals of the cathode power supply terminal row in sequence, and the order control of the LED lamp beads in the LED lamp bead strip is realized by controlling the power supply at the corresponding positions of the anode power supply terminal row and the cathode power supply terminal row.

[0014] The LED lamp beads in the LED lamp bead bar are evenly divided into a plurality of partitioned LED lamp bead units according to the position sequence, and the circumference of the aluminum circuit substrate is provided with fixed installation holes, which are installed on the adjustable lighting position bracket through the fixed installation holes.

[0015] The same frequency confocal LED light source structure for three-dimensional defect detection on the product surface mentioned above, the adjustable lighting position bracket includes a front lens ring, a middle support plate and a rear lighting light source connection seat,

[0016] The front end lens ring, the middle support plate and the rear end lighting source connection seat are distributed in sequence from front to back, and are connected through connecting guide rods located at the four corners. The front end lens ring is sleeved on the outside of the sampling lens assembly, the middle support plate is located at the rear end of the sampling lens assembly, and is provided with a first light source irradiation hole. The rear end of the rear end lighting source connection seat is installed with an LED lighting source adjustment base for realizing the left and right adjustment function of the LED lighting source assembly, the rear end lighting source connection seat is provided with a second light source irradiation hole, and the LED lighting source adjustment base is provided with a third light source irradiation hole.

[0017] The same-frequency confocal LED light source structure for three-dimensional defect detection on the product surface mentioned above, the middle support plate and the rear-end lighting light source connection seat are made of gold-plated brass.

[0018] The same-frequency confocal LED light source structure for three-dimensional defect detection on the product surface mentioned above, the LED lighting light source adjustment base includes an adjustment base plate, the two side edges of the adjustment base plate are vertically bent toward the rear end to form a guide side plate, and the rear of the adjustment base plate is equipped with a left movable guide rod and a right movable guide rod that penetrate the two side guide side plates, the left movable guide rod and the right movable guide rod are arranged oppositely, the left movable guide rod is sleeved with a rotatably screwed left movable threaded sleeve, the right movable guide rod is sleeved with a rotatably screwed right movable threaded sleeve, both sides of the left movable threaded sleeve are fixed with a movable left slider, and both sides of the right movable threaded sleeve are fixed with a movable right slider, the four corners of the aluminum circuit substrate are respectively fixed to the left slider and the right slider at the corresponding positions through fixed guide pillars,

[0019] The left movable guide rod and the right movable guide rod will respectively drive the left movable threaded sleeve and the right movable threaded sleeve to move during the rotation process. After the left movable threaded sleeve or the right movable threaded sleeve moves, the aluminum circuit substrate is moved to the left or right position, so that the LED lamp bead illumination focus point and the sampling focus point of the linear array CCD sensor pixel point are located at the same position, thereby realizing confocal work.

[0020] The same-frequency confocal LED light source structure for three-dimensional defect detection on the product surface mentioned above, the anode power supply terminal row and the cathode power supply terminal row are both composed of multiple groups of spaced terminal unit rows; the spacing L1 of the LED lamp beads is 0.15mm, and the width L2 of the LED lamp beads is 0.33mm; the rated voltage of the LED lamp beads is 3V, the rated probability is 0.45w, and it is overloaded to 11V, 4A when instantly lit.

[0021] The same-frequency confocal LED light source structure for three-dimensional defect detection on the product surface mentioned above, the rotating ends of the left movable guide rod and the right movable guide rod are provided with straight nuts for easy rotation.

[0022] The same-frequency confocal LED light source structure for the aforementioned three-dimensional defect detection on the product surface is as follows: let f be the operating frequency of a single pixel of the linear array CCD sensor, the width of each pixel be i, the magnification of the scanning optical system be 1 / X, and the corresponding width of each pixel on the object image be i·X, the magnification of the lens be 1 / Y, the width of a single LED lamp bead unit plus two LED lamp bead units be s, and the object image range that a single LED lamp bead unit needs to illuminate is S=s·Y, which illuminates S / i·X pixels on the linear array CCD sensor, and the time T1=S·f / i·X that each LED lamp bead needs to light up, and the overlapping power time T2 of adjacent LED lamp bead units is at least 1 / f and less than 2 / f, wherein X and Y are characteristic parameters of the sampling lens assembly.

[0023] The same-frequency confocal LED light source structure for the aforementioned three-dimensional defect detection on the product surface, wherein the number of LED lamp beads in the LED lamp bead unit is one or more.

[0024] The same-frequency confocal LED light source structure for the aforementioned three-dimensional defect detection on the product surface, the LED lamp beads can be lit or extinguished individually, and the LED lamp beads are distributed in odd and even fields. The anodes of the odd-numbered LED lamp beads are controlled by the a power supply, and the a power supply is the signal Pa array. The anodes of the even-numbered LED lamp beads are controlled by the b power supply, and the b power supply is the signal Pb array.

[0025] The beneficial effects of the present invention are as follows: the same-frequency co-focusing LED light source structure for detecting three-dimensional defects on the surface of a product of the present invention has high reliability in fixing with the lens assembly, and is convenient for adjusting the illumination focal length of the LED illumination light source, and instantly lighting up the LED lamp beads, which can be overloaded, and the brightness is significantly improved, and is synchronously lit up in sequence with the pixels of the linear array CCD sensor, and according to the attribute characteristics of the three-dimensional defects on the surface of the product, the same-frequency co-focusing LED illumination light source is selected for illumination, which is convenient for projection imaging detection of three-dimensional defects (including three-dimensional surface defects such as protrusions and depressions), and the LED illumination light source can instantly light up the LED lamp beads, and the LED illumination light source can light up a single point, and according to this working characteristic, the LED at the corresponding position of the mapping control lighting is controlled. D lamp beads, instantaneous lighting of LED lamp beads, can be overloaded, the brightness is significantly improved, and because of the short power-on time, low actual power consumption, low heat generation, no longer need active heat dissipation components, the overall small size, easy to install on-site product surface detection, suitable for various industrial environments, and synchronized with the pixels of the CCD sensor to light up in sequence, while meeting the lighting needs, greatly saving energy consumption, extending the life, and realizing the confocal working process (for three-dimensional defects) through optical principles, greatly improving the accuracy of three-dimensional defect detection sampling on the product surface, and the heat dissipation needs can be met through the aluminum circuit substrate, with good lighting effect, high heat dissipation efficiency, high overall stability, ingenious design, novel conception, and good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of a same-frequency confocal LED light source structure for three-dimensional defect detection on a product surface of the present invention;

[0027] Figure 2 The side view of the same frequency confocal LED light source structure for three-dimensional defect detection on the product surface of the present invention Figure 1 ;

[0028] Figure 3 The side view of the same frequency confocal LED light source structure for three-dimensional defect detection on the product surface of the present invention Figure 2 ;

[0029] Figure 4It is a structural schematic diagram of the LED lighting source assembly of the present invention;

[0030] Figure 5 It is a schematic diagram of the structure of the LED lamp bead strip of the LED of the present invention.

[0031] The meanings of the symbols in the accompanying drawings are as follows:

[0032] 1: Sampling lens assembly; 2: LED lighting source assembly; 201: Aluminum circuit substrate; 202: LED lamp bead strip; 2021: LED lamp bead; 203: Anode power supply terminal block; 204: Cathode power supply terminal block; 205: Fixed mounting hole; 206: Fixed guide column; 3: Adjustable lighting position bracket; 301: Front lens ring; 302: Middle support plate; 3021: First light source irradiation hole; 3031: Second light source irradiation hole; 303: Connecting guide rod; 304: Rear lighting source connection seat; 3041: Third light source irradiation hole; 3042: Adjusting base plate; 3043: Guide side plate; 3044: Left moving guide rod; 3045: Right moving guide rod; 3046: Left moving threaded sleeve; 3047: Right moving threaded sleeve; 3048: Left slider; 3049: Right slider; 305: Slotted nut. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings.

[0034] like Figure 1-Figure 5 As shown, the same-frequency confocal LED light source structure for three-dimensional defect detection on the product surface of the present invention comprises a sampling lens assembly 1, an LED lighting source assembly 2 and an adjustable lighting position bracket 3.

[0035] The LED lighting source assembly 2 is installed at the rear end of the sampling lens assembly 1 through an adjustable lighting position bracket 3.

[0036] The LED lighting source assembly 2 is a same-frequency confocal LED lighting source, and the LED lighting beads inside can be controlled to light up or extinguish at a single point, and are evenly divided into a plurality of partitioned LED lamp bead units according to the position sequence. The partitioned LED lamp bead units are sequentially lit or extinguished according to the clock frequency at which the pixel points of the linear array CCD sensor are sequentially exposed along the working direction, so that the LED lighting source assembly 2 and the linear array CCD sensor complete the same-frequency synchronous operation;

[0037] The LED lighting source assembly 2 can adjust the position of the LED lighting source assembly 2 in the left and right directions through the adjustable lighting position bracket 3, so that the lighting focus point of the LED lamp beads inside and the sampling focus point of the linear array CCD sensor pixel points are located at the same position to achieve confocal work.

[0038] The LED lighting source assembly 2 includes an aluminum circuit substrate 201, an LED lamp bead strip 202 is arranged in the middle of the aluminum circuit substrate 201, and the LED lamp bead strip 202 has multiple LED lamp beads 2021 distributed in sequence at equal intervals, an anode power supply terminal row 203 is arranged on the aluminum circuit substrate 201 on one side of the LED lamp bead strip 202, and a cathode power supply terminal row 204 is arranged on the aluminum circuit substrate 201 on the other side of the LED lamp bead strip 202. The power supply terminal row 204 is arranged on the opposite side, and the positive poles of each LED lamp bead 2021 in the LED lamp bead strip 202 are respectively connected to the terminals of the anode power supply terminal row 203 in sequence, and the negative poles of each LED lamp bead 2021 in the LED lamp bead strip 202 are respectively connected to the terminals of the cathode power supply terminal row 204 in sequence. By controlling the power supply at the corresponding positions of the anode power supply terminal row 203 and the cathode power supply terminal row 204, the order control of the LED lamp bead 2021 in the LED lamp bead strip 202 is realized.

[0039] The LED lamp beads 2021 in the LED lamp bead strip 202 are evenly divided into a plurality of partitioned LED lamp bead units according to the position sequence. The aluminum circuit substrate 201 is provided with a fixed mounting hole 205 around it, and is mounted on the adjustable lighting position bracket 3 through the fixed mounting hole 205. The anode power supply terminal block 203 and the cathode power supply terminal block 204 both include a plurality of groups of spaced-apart terminal unit rows. Due to the different numbers of lamp beads required, the terminal blocks on the market may not be so exactly matched, and multiple groups need to be used in combination.

[0040] The adjustable lighting position bracket 3 includes a front lens ring 301, a middle support plate 302 and a rear lighting source connection seat 304.

[0041] The front end lens ring 301, the middle support piece 302 and the rear end lighting source connection seat 304 are distributed in sequence from front to back, and are connected through connecting guide rods 303 located at the four corners. The front end lens ring 301 is sleeved on the outside of the sampling lens assembly 1, the middle support piece 302 is located at the rear end of the sampling lens assembly 1, and is provided with a first light source irradiation hole 3021. The rear end of the rear end lighting source connection seat 304 is installed with an LED lighting source adjustment base for realizing the left and right adjustment function of the LED lighting source assembly 2. The rear end lighting source connection seat 304 is provided with a second light source irradiation hole 3031, and the LED lighting source adjustment base is provided with a third light source irradiation hole 3041.

[0042] Preferably, the middle support plate 302 and the rear end lighting source connection seat 304 are made of gold-plated brass, which improves the structural stability while achieving moisture-proof and corrosion-resistant effects, good heat uniformity, and gold plating is resistant to oxidation and corrosion, and has good electrical shielding performance.

[0043] Preferably, the LED lighting source adjustment base includes an adjustment base plate 3042, both sides of the adjustment base plate 3042 are vertically bent toward the rear end to form a guide side plate 3043, and a left movable guide rod 3044 and a right movable guide rod 3045 penetrating the guide side plates 3043 on both sides are installed behind the adjustment base plate 3042, and the left movable guide rod 3044 and the right movable guide rod 3045 are arranged opposite to each other, and a rotating screw is sleeved on the left movable guide rod 3044. The left movable threaded sleeve 3046 is connected to the right movable guide rod 3045, and the right movable threaded sleeve 3047 is sleeved on the right movable guide rod 3045. The left movable threaded sleeve 3046 is fixed with a movable left slider 3048 on both sides, and the right movable threaded sleeve 3047 is fixed with a movable right slider 3049 on both sides. The four corners of the aluminum circuit substrate 201 are respectively fixed to the left slider 3048 and the right slider 3049 at the corresponding positions through the fixed guide pillars 206.

[0044] The left movable guide rod 3044 and the right movable guide rod 3045 will respectively drive the left movable threaded sleeve 3046 and the right movable threaded sleeve 3047 to move during the rotation process. After the left movable threaded sleeve 3046 or the right movable threaded sleeve 3047 moves, the aluminum circuit substrate 201 is moved to the left or right position, so that the LED lamp bead illumination focus point and the sampling focus point of the linear array CCD sensor pixel point are located at the same position, thereby realizing confocal operation.

[0045] The anode power supply terminal row 203 and the cathode power supply terminal row 204 both include a plurality of groups of spaced-apart terminal unit rows; the spacing L1 of the LED lamp bead 2021 is 0.15mm, and the width L2 of the LED lamp bead 2021 is 0.33mm; the rated voltage of the LED lamp bead 2021 is 3V, and the rated probability is 0.45w. When it is instantly lit up and overloaded to 11V, 4A, it can achieve an overload of 97 times, and the brightness is significantly improved. Moreover, due to the short power-on time, it will not be damaged, and the actual power consumption is low, the heat generation is small, and active heat dissipation components are no longer required. The overall size is small, which is convenient for on-site installation, and it is lit up in synchronization with the pixels scanned by the linear array CCD sensor. While meeting the lighting needs, it greatly saves energy and extends the life.

[0046] Preferably, the rotating ends of the left movable guide rod 3044 and the right movable guide rod 3045 are provided with a slotted nut 305 for easy rotation, so as to facilitate the selection and adjustment of the LED lighting source assembly 2 and the sampling lens assembly 1 to achieve confocal operation.

[0047] Preferably, let f be the operating frequency of a single pixel of the linear array CCD sensor, the width of each pixel be i, the magnification of the scanning optical system be 1 / X, and the corresponding width of each pixel on the object image be i·X, the magnification of the lens be 1 / Y, the width of a single LED lamp bead unit plus two LED lamp bead units be s, and the object image range that needs to be illuminated by a single LED lamp bead unit is S=s·Y, which illuminates S / i·X pixels on the linear array CCD sensor, and the time T1=S·f / i·X that each LED lamp bead needs to light up, and the overlapping power time T2 of adjacent LED lamp bead units is at least 1 / f and less than 2 / f, wherein X and Y are characteristic parameters of the sampling lens assembly, and in the embodiment of the present invention, X=Y=10.

[0048] Preferably, there is one or more LED lamp beads 2021 in the LED lamp bead unit, and different numbers of lamp beads are selected according to the sampling size to form the LED lamp bead unit.

[0049] The LED lamp beads 2021 can be lit or extinguished individually, and the LED lamp beads 2021 are distributed in odd and even fields. The anodes of the odd-numbered LED lamp beads are controlled by power supply a, which is a signal Pa array. The anodes of the even-numbered LED lamp beads are controlled by power supply b, which is a signal Pb array. That is, the lamp beads are controlled in odd and even fields. The anodes of the odd-numbered lamp beads are all connected in parallel to the MOS tube A, and the anodes of the even-numbered lamp beads are all connected in parallel to the MOS tube B. The signal Pa controls the MOS tube A, and the signal Pb controls the MOS tube B. When the MOS tube control voltage is at a high level, the MOS tube is turned on, and the lamp bead anode obtains external power supply; at the same time, the cathode of each lamp bead is grounded through a MOS tube separately. When the voltage controlled by the MOS tube is at a high level, the MOS tube is turned on, the cathode is grounded, and is at a low level, and the lamp bead is lit.

[0050] The same-frequency confocal LED light source structure for three-dimensional defect detection on the product surface of the present invention controls the lighting or extinguishing of the LED lamp beads in the partitioned LED lamp bead units at the corresponding positions in the LED lighting source according to the measured clock frequency of the linear array CCD sensor pixel points sequentially exposed along the working direction, so that the two work synchronously at the same frequency. A specific embodiment:

[0051] First, light up the first LED bead. After the first LED bead lights up for 10μs, the second LED bead lights up. After another 0.5μs, the first LED bead turns off. After the second LED bead lights up for 10.5μs, the third LED bead lights up. After another 0.5μs, the second LED bead turns off. . . By analogy, except for the first and last LED lamp beads, which are lit for 10.5μs, the lighting time of each lamp bead is 11μs. That is to say, after the previous LED lamp bead is lit for 10μs, the next LED lamp bead is lit, and the two adjacent lamp beads are lit for 0.5μs. Then the previous LED lamp bead is turned off, and the next LED lamp bead is lit for 10μs. When a single LED lamp bead is lit, the middle is bright and the edge is dark. In this case, the pixel lighting condition corresponding to the edge of the LED lamp bead is worse than that corresponding to the middle. Within 0.5μs when the two adjacent LED lamp beads are lit, the halo edges of the two LED lamp beads overlap, and the edge brightness is improved, which increases the continuity and uniformity of the lighting and provides a good lighting environment.

[0052] The light emitted by the LED lamp beads passes through the lens to form a parallel light beam. The larger the aperture of the lens, the brighter the light emitted. The aperture of conventional industrial camera lenses generally does not exceed F / 2.8. In order to maximize the brightness, we have to choose a large aperture camera lens. The number of LED lamp beads that the lens can match is related to the frame size of the lens (sampling lens assembly 1). The largest mass-produced frame size is Fuji's GFX medium frame, which is a 44*33mm rectangle, so the diameter of the lens's imaging circle is the length of the diagonal of the frame rectangle, 55mm. The size of the LED lamp beads used in the light bar is 0.33*0.81*0.15mm, 0.33mm is the width of the LED lamp beads, and the spacing between the LED lamp beads is 0.15mm, so each lamp bead requires a width of 0.48mm. 55 divided by 0.48 is approximately equal to 114.6. In order to maximize the use of the imaging circle, an even number is taken for the convenience of symmetrical design of the circuit, so the light bar has 116 lamp beads. This number of LED lamp beads can basically meet the use of all linear array CCD sensors on the market. And the Fuji GFX lens with the largest aperture is the Zhongyi Optical 85mm F / 1.2 lens, the rear flange focal length of the lens is 26.7mm, and the light bar is 26.7mm away from the rear flange plane of the lens.

[0053] In summary, the same-frequency confocal LED light source structure for three-dimensional defect detection on the surface of a product of the present invention has high reliability in fixing with the lens assembly, and is convenient for adjusting the illumination focal length of the LED illumination light source, and instantly lighting up the LED lamp beads, which can be overloaded, and the brightness is significantly improved, and is synchronously lit up in sequence with the pixels of the linear array CCD sensor. According to the attribute characteristics of the three-dimensional defects on the surface of the product, the same-frequency confocal LED illumination light source is selected for illumination, which is convenient for projection imaging detection of three-dimensional defects (including three-dimensional surface defects such as protrusions and depressions), and the LED illumination light source can instantly light up the LED lamp beads, and the LED illumination light source can light up a single point. According to this working characteristic, the mapping control lights up the LED lamp at the corresponding position Beads, instantaneous lighting of LED lamp beads, can be overloaded, the brightness is significantly improved, and because of the short power-on time, low actual power consumption, low heat generation, no longer need active heat dissipation components, the overall small size, easy to install on-site product surface detection, suitable for various industrial environments, and synchronized with the pixels of the CCD sensor to light up in sequence, while meeting the lighting needs, greatly saving energy consumption, extending the life, and realizing the confocal working process (for three-dimensional defects) through optical principles, greatly improving the accuracy of three-dimensional defect detection sampling on the product surface, and the heat dissipation needs can be met through the aluminum circuit substrate, with good lighting effect, high heat dissipation efficiency, high overall stability, ingenious design, novel conception, and good application prospects.

[0054] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A same-frequency confocal LED light source structure for three-dimensional defect detection on product surface, characterized in that: It comprises a sampling lens assembly (1), an LED lighting source assembly (2) and an adjustable lighting position bracket (3), The LED lighting source assembly (2) is mounted on the rear end of the sampling lens assembly (1) via an adjustable lighting position bracket (3). The LED lighting source assembly (2) is a same-frequency confocal LED lighting source, and the LED lighting beads therein can be controlled to light up or extinguish at a single point, and are evenly divided into a plurality of partitioned LED lamp bead units according to the position sequence, and the partitioned LED lamp bead units are sequentially lit or extinguished according to the clock frequency at which the pixel points of the linear array CCD sensor are sequentially exposed along the working direction, so that the LED lighting source assembly (2) and the linear array CCD sensor complete the same-frequency synchronous operation; The LED lighting source component (2) can adjust the position of the LED lighting source component (2) in the left and right directions through an adjustable lighting position bracket (3), so that the lighting focus point of the LED lamp beads therein and the sampling focus point of the pixel points of the linear array CCD sensor are located at the same position, thereby realizing a co-focusing operation. The LED lighting source component (2) comprises an aluminum circuit substrate (201), an LED lamp bead bar (202) is arranged in the middle of the aluminum circuit substrate (201), the LED lamp bead bar (202) has a plurality of LED lamp beads (2021) distributed in sequence at equal intervals, an anode power supply terminal block (203) is arranged on the aluminum circuit substrate (201) on one side of the LED lamp bead bar (202), and the LED lamp bead bar (202) has a plurality of LED lamp beads (2021) distributed in sequence at equal intervals, and an anode power supply terminal block (203) is arranged on the aluminum circuit substrate (201) on one side of the LED lamp bead bar (202). A cathode power supply terminal row (204) is arranged on the aluminum circuit substrate (201) on one side, and the anode power supply terminal row (203) is arranged on the opposite side of the cathode power supply terminal row (204). The positive poles of the LED lamp beads (221) in the LED lamp bead strip (202) are respectively connected to the terminals of the anode power supply terminal row (203) in sequence, and the negative poles of the LED lamp beads (221) in the LED lamp bead strip (202) are respectively connected to the terminals of the cathode power supply terminal row (204) in sequence. The order control of the LED lamp beads (221) in the LED lamp bead strip (202) is realized by controlling the power supply at the corresponding positions of the anode power supply terminal row (203) and the cathode power supply terminal row (204). The LED lamp beads (221) in the LED lamp bead strip (202) are evenly divided into a plurality of partitioned LED lamp bead units according to the position sequence; the aluminum circuit substrate (201) is provided with a fixed mounting hole (205) on its circumference, and is mounted on an adjustable lighting position bracket (3) through the fixed mounting hole (205); the adjustable lighting position bracket (3) comprises a front lens ring (301), a middle support sheet (302) and a rear lighting source connection seat (304); The front lens collar (301), the middle support sheet (302) and the rear illumination light source connection seat (304) are sequentially arranged from front to back and are connected through connecting guide rods (303) located at four corners. The front lens collar (301) is sleeved on the outside of the sampling lens assembly (1). The middle support sheet (302) is located at the rear end of the sampling lens assembly (1) and is provided with a first light source irradiation hole (3021). The rear end of the rear illumination light source connection seat (304) is provided with an LED illumination light source adjustment base for realizing the left-right adjustment function of the LED illumination light source assembly (2). The rear end illumination light source connection seat (304) is provided with a second light source irradiation hole (3031). The LED illumination light source adjustment base is provided with a third light source irradiation hole (3041). The LED illumination light source adjustment base comprises an adjustment base plate (3042). Both sides of the adjustment base plate (3042) extend backward. The ends of the adjusting base plate (3042) are bent vertically to form a guide side plate (3043). A left movable guide rod (3044) and a right movable guide rod (3045) penetrating the guide side plates (3043) on both sides are installed behind the adjusting base plate (3042). The left movable guide rod (3044) and the right movable guide rod (3045) are arranged opposite to each other. A left movable threaded sleeve (3046) is sleeved on the left movable guide rod (3044) and a left movable threaded sleeve (3046) is rotatably screwed on the right movable guide rod (3045). 45) is sleeved with a right movable threaded sleeve (3047) which is rotatably screwed, and movable left sliders (3048) are fixed on both sides of the left movable threaded sleeve (3046), and movable right sliders (3049) are fixed on both sides of the right movable threaded sleeve (3047), and the four corners of the aluminum circuit substrate (201) are respectively fixed to the left slider (3048) and the right slider (3049) at the corresponding positions through fixed guide pillars (206). The left movable guide rod (3044) and the right movable guide rod (3045) will respectively drive the left movable threaded sleeve (3046) and the right movable threaded sleeve (3047) to move during the rotation process. After the left movable threaded sleeve (3046) or the right movable threaded sleeve (3047) moves, the aluminum circuit substrate (201) is moved to the left or right position, so that the LED lamp bead illumination focus point and the sampling focus point of the linear array CCD sensor pixel point are located at the same position, thereby realizing the co-focusing operation. The anode power supply terminal row (203) and the cathode power supply terminal row (204) both include a plurality of groups of spaced terminal unit rows. The spacing L1 of the LED lamp bead (2021) is 0.15 mm, and the width L2 of the LED lamp bead (2021) is 0.33 mm. The rated voltage of the LED lamp bead (2021) is 3 V, and the rated probability is 0.45 W, and it is overloaded when it is instantly lit.

2. The same frequency confocal LED light source structure for three-dimensional defect detection on product surface according to claim 1, characterized in that: The middle support plate (302) and the rear end lighting light source connection seat (304) are made of gold-plated brass.

3. The same frequency confocal LED light source structure for three-dimensional defect detection on product surface according to claim 1, characterized in that: The rotating ends of the left movable guide rod (3044) and the right movable guide rod (3045) are provided with slotted nuts (305) for easy rotation.

4. The same frequency confocal LED light source structure for three-dimensional defect detection on product surface according to claim 1, characterized in that: Assume that f is the operating frequency of a single pixel of the linear array CCD sensor, the width of each pixel is i, the magnification of the scanning optical system is 1 / X, and the width of each pixel on the object image is i·X, the magnification of the lens is 1 / Y, the width of a single LED lamp bead unit plus two LED lamp bead units is s, and the object image range that a single LED lamp bead unit needs to illuminate is S=s·Y, which illuminates S / i·X pixels on the linear array CCD sensor. The time T1 that each LED lamp bead needs to light up is S·f / i·X, and the overlapping power time T2 of adjacent LED lamp bead units is at least 1 / f and less than 2 / f, where X and Y are characteristic parameters of the sampling lens assembly (1).

5. The same frequency confocal LED light source structure for three-dimensional defect detection on product surface according to claim 1, characterized in that: The number of LED lamp beads (21) in the LED lamp bead unit is one or more.

6. The same frequency confocal LED light source structure for three-dimensional defect detection on product surface according to claim 5, characterized in that: The LED lamp beads (2021) can be lit or extinguished individually, and the LED lamp beads (2021) are distributed in odd and even fields, the anodes of the odd-numbered LED lamp beads are controlled by power supply a, which is a signal Pa array, and the anodes of the even-numbered LED lamp beads are controlled by power supply b, which is a signal Pb array.

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