Illumination system combining visible light illumination and adjustable line laser illumination

Abstract

The utility model relates to an illumination system combining visible light and adjustable line laser. The illumination system comprises a visible light Kohler illumination system and an adjustable line laser illumination system. The visible light Kohler illumination system sequentially comprises an LED light source, a collecting lens group A, an achromatic lens group B and a dichroscope F along an optical axis from a light source to an image plane and provides stable and uniform visible light illumination, and the adjustable line laser illumination system sequentially comprises a laser, a collimating lens group C, a Powell prism D, a zoom lens group E and the dichroscope F along the optical axis from the light source to the image plane. The adjustable linear laser illumination system is used for providing uniform linear laser illumination with adjustable light spot size, and the dichroscope F is arranged at the light path intersection of the visible light Kohler illumination system and the adjustable linear laser illumination system, so that visible light and laser are finally imaged at the same position; therefore, an illumination light path capable of freely switching visible light illumination and line laser illumination in different wave bands is provided, and detection requirements can be met by using corresponding illumination modes according to different characteristics of a detected product.

Description

Technical Field

[0001] The present application relates to the technical field of lighting systems, and in particular to a lighting system combining visible light lighting with adjustable linear laser lighting. Background Art

[0002] Machine vision is to use machines to replace human eyes to make measurements and judgments. Traditionally, imaging systems use more area array cameras, that is, the imaging sensor of the camera is rectangular, with multiple photosensitive units in the horizontal and vertical dimensions, which can collect images of a square area. Systems that use area array sensors are collectively referred to as area array systems. In the imaging system using line scan cameras, the imaging sensor is long and strip-shaped, and multiple photosensitive units are arranged in a row, which can collect images of a long and thin strip area. When the object to be detected and the line scan system have relative motion, each piece of data can be continuously collected and finally synthesized into a complete picture. In some applications that pursue high precision, the line scan system has more cost and technical advantages than the area array system. At present, line scan cameras are an important component of many machine vision systems. In precision detection applications such as electronic manufacturing, LCD screen size measurement, and circuit board pin detection, line scan cameras are often used to obtain images. When scanning different features of the same product, different lighting methods are often required to meet the detection requirements and realize product detection. The existing related light sources usually use separate dual-system lighting, which is complicated to operate and not convenient for free and fast switching between visible light and line laser lighting. Utility Model Content

[0003] In view of the above problem that there is no illumination optical path that can realize free switching between line lasers of different wavelength bands and visible light illumination, this application proposes an illumination system combining visible light illumination and adjustable line laser illumination, which adopts the following technical solution:

[0004] The present application proposes an illumination system combining visible light illumination and adjustable line laser illumination, comprising a visible light Köhler illumination system and an adjustable line laser illumination system, wherein the visible light Köhler illumination system comprises an LED light source, a condenser lens group A, an achromatic lens group B and a dichroic mirror F in sequence along the optical axis from the light source to the image plane, and the adjustable line laser illumination system comprises a laser, a collimating lens group C, a Powell prism D, a zoom lens group E and the dichroic mirror F in sequence along the optical axis from the light source to the image plane, wherein the dichroic mirror F is arranged at the intersection of the optical paths of the visible light Köhler illumination system and the adjustable line laser illumination system, and the visible light and the laser are respectively reflected and transmitted by the dichroic mirror F and imaged on the same image plane G.

[0005] By adopting the above technical scheme, a visible light Köhler illumination system is used to provide stable and uniform visible light illumination in the form of Köhler illumination, an adjustable line laser illumination system is used to provide uniform, in-line line laser illumination with adjustable spot size, and a dichroic mirror is used to make the visible light and line laser finally imaged at the same position, thereby providing an illumination optical path in which visible light illumination of different bands and line laser illumination can be freely switched, and corresponding illumination methods can be used for different features of the inspection product to meet the inspection requirements and realize product detection.

[0006] Preferably, the condenser lens group A includes a meniscus lens L1 with positive focal length; the achromatic lens group B includes a double cemented lens U1 composed of a biconcave lens L2 and a biconvex lens L3.

[0007] By adopting the above technical solution, the condenser group A can converge the light emitted by the LED light source, and the achromatic mirror group B corrects the chromatic aberration of the light entering it, and also converges the light, thereby providing stable and uniform visible light illumination in the form of Köhler illumination, and the light source utilization rate reaches 94%.

[0008] Preferably, the collimating lens group C includes a biconvex lens L4 in sequence, and the zoom lens group E includes a biconcave lens L6, a biconvex lens L7, a double cemented lens U2 composed of a biconcave lens L8 and a biconvex lens L9, a meniscus lens L10 and a meniscus lens L11 in sequence.

[0009] By adopting the above technical solution, the collimating lens group C collimates the light emitted by the laser to make it parallel light. The Powell prism D divides the incident laser beam into a straight line with uniform light density, good stability and good linearity. The zoom lens group E images the light formed by the front group on the image plane G, and can adjust the spot size of the image plane G by changing its own focal length.

[0010] Preferably, the positions of the biconcave lens L8, the biconvex lens L9, the meniscus lens L10 and the meniscus lens L11 are fixed, and the relative positions of the biconcave lens L6 and the biconvex lens L7 are fixed and can be moved along the optical axis.

[0011] By adopting the above technical solution, the focal length of the zoom lens group E is changed by moving the double concave lens L6 and the double convex lens L7 forward and backward along the optical axis and changing their relative positions with the rear group L8~L11, thereby adjusting the size of the linear light spot projected on the image plane G within a certain range.

[0012] Preferably, the visible light Köhler illumination system is arranged in a vertical direction, the adjustable line laser illumination system is arranged in a horizontal direction, and the dichroic mirror F is arranged at 45°.

[0013] By adopting the above technical solution, the optical path of the visible light Köhler illumination system and the optical path of the adjustable line laser illumination system are perpendicular to each other and intersect at the dichroic mirror F. The dichroic mirror F forms an angle of 45° with both optical paths, so that the visible light and the line laser passing through the dichroic mirror F are imaged on the same image plane G through the same straight line.

[0014] Preferably, the dichroic mirror F transmits light with a wavelength below 430 nm, and reflects light with a wavelength above 430 nm.

[0015] Preferably, the laser wavelength emitted by the laser is 425 nm.

[0016] By adopting the above technical solution, the dichroic mirror F transmits the laser light emitted by the laser and reflects the visible light emitted by the LED light source.

[0017] Preferably, each lens of the condenser lens group A, the achromatic lens group B, the collimating lens group C, the Powell prism D, and the zoom lens group E is a spherical mirror.

[0018] By adopting the above technical solution, the spherical lens can be easily and stably manufactured in batches at a relatively low cost.

[0019] In summary, the present application proposes an illumination system that combines visible light illumination with adjustable line laser illumination. The visible light Köhler illumination system is used to provide stable and uniform visible light illumination in the form of Köhler illumination. The adjustable line laser illumination system is used to provide uniform, in-line laser illumination with adjustable spot size. The visible light and the laser are finally imaged on the same image plane through a dichroic mirror, thereby providing an illumination optical path in which visible light illumination of different bands and adjustable line laser illumination can be freely switched. Corresponding illumination methods can be used for different features of the detected product to meet the detection requirements and realize product detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate the embodiments and are used together with the description to explain the principles of the present application. It will be easy to recognize other embodiments and many expected advantages of the embodiments because they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale with each other. The same reference numerals refer to corresponding similar parts.

[0021] Figure 1 It is a structural schematic diagram of an illumination system combining visible light and adjustable linear laser according to an embodiment of the present application.

[0022] Figure 2 Schematic diagram of the optical path of the visible light Kohler illumination system in the embodiment of the present application.

[0023] Figure 3 1 is a point arrangement diagram of each field of view of the visible light Köhler illumination system in the embodiment of the present application.

[0024] Figure 4 Schematic diagram of the X-axis optical path of the adjustable linear laser illumination system in the embodiment of the present application.

[0025] Figure 5 Schematic diagram of the Y-axis optical path of the adjustable linear laser illumination system in the embodiment of the present application.

[0026] Figure 6 1 is a diagram of the various fields of view of the adjustable linear laser illumination system in an embodiment of the present application. DETAILED DESCRIPTION

[0027] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It should also be noted that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings.

[0028] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0029] Figure 1 is a schematic diagram of a lighting system combining visible light and adjustable linear laser according to an embodiment of the present application, Figure 1 The embodiment of the present application discloses an illumination system combining visible light illumination and adjustable line laser illumination, including a visible light Kohler illumination system and an adjustable line laser illumination system. The visible light Kohler illumination system includes an LED light source, a condenser lens group A, an achromatic lens group B and a dichroic mirror F in sequence along the optical axis from the light source to the image plane. The adjustable line laser illumination system includes a laser, a collimating lens group C, a Powell prism D, a zoom lens group E and the dichroic mirror F in sequence along the optical axis from the light source to the image plane. The dichroic mirror F is arranged at the intersection of the optical paths of the visible light Kohler illumination system and the adjustable line laser illumination system. The visible light and the laser are respectively reflected and transmitted by the dichroic mirror F and imaged on the same image plane G. The visible light Kohler illumination system is used to provide stable and uniform visible light illumination in the form of Kohler illumination. The adjustable line laser illumination system is used to provide uniform, inline line laser illumination with adjustable spot size. The visible light and the laser are finally imaged at the same position through the setting of the dichroic mirror, thereby realizing the combination of visible light illumination and high-energy line laser illumination. The present application provides an illumination optical path that can freely switch between visible light illumination in different bands and line laser illumination, and can use corresponding illumination methods according to different characteristics of the detection product to meet the detection requirements and realize product detection.

[0030] In a preferred embodiment, the visible light Kohler illumination system is arranged in a vertical direction, the adjustable line laser illumination system is arranged in a horizontal direction, and the dichroic mirror F is arranged at 45°, which is shared by the visible light Kohler illumination system and the adjustable line laser illumination system, and can transmit the laser light emitted by the laser and reflect the visible light emitted by the LED light source. The optical path of the visible light Kohler illumination system and the optical path of the adjustable line laser illumination system are perpendicular to each other and intersect at the dichroic mirror F, which forms an angle of 45° with both optical paths, so that the visible light and the line laser passing through the dichroic mirror F pass through the same straight line and form an image at the same position.

[0031] In a preferred embodiment, the dichroic mirror F transmits light with a wavelength below 430 nm and reflects light with a wavelength above 430 nm. The wavelength of visible light emitted by the LED light source is about 400 nm to 700 nm, and the wavelength of laser light emitted by the laser is 425 nm, so the dichroic mirror F can transmit the laser light emitted by the laser and reflect the visible light with a wavelength above 430 nm emitted by the LED light source.

[0032] Figure 2 Schematic diagram of the optical path of the visible light Kohler illumination system in the embodiment of the present application. Figure 2 The specific structure and implementation principle of the visible light Kohler illumination system in the illumination system combining visible light illumination with adjustable linear laser illumination of the present application are specifically described: the visible light Kohler illumination system is vertically arranged, and includes a centrally aligned LED light source, a positive focal meniscus lens L1, a double cemented lens U1 composed of a double concave lens L2 and a double convex lens L3, and a dichroic mirror F arranged at 45° in sequence along the optical axis from the light source to the image plane. The positive focal meniscus lens L1 constitutes a condenser lens group A, the double cemented lens U1 constitutes an achromatic lens group B, and the dichroic mirror F transmits light with a wavelength below 430nm and reflects light with a wavelength above 430nm.

[0033] When in use, the LED light source emits visible light with a wavelength of about 400nm to 700nm. The condenser group A converges the light emitted by the LED light source with a divergence angle of 120°. The achromatic lens group B corrects the chromatic aberration of the light and also converges the light. The light enters the dichroic mirror F at 45°. The light with a wavelength of more than 430nm is reflected and forms an inverted and enlarged clear real image on the image plane G, providing stable and uniform visible light illumination in the form of Kohler illumination. Figure 3 is a point diagram of each field of view of the visible light Kohler illumination system in the embodiment of the present application, referring to Figure 3 The spot radius of each field of view is basically the same, and a uniform bright spot can be obtained after passing through each lens, which verifies the effect of the visible light Köhler illumination system, and its light source utilization rate can reach 94%.

[0034] Figure 4is a schematic diagram of the X-axis optical path of the adjustable line laser illumination system in an embodiment of the present application, Figure 5 Schematic diagram of the Y-axis optical path of the adjustable line laser illumination system in the embodiment of the present application. Figure 4 and Figure 5 The specific structure and implementation principle of the adjustable line laser lighting system in the lighting system that combines visible light lighting and adjustable line laser lighting in the present application are specifically described: the adjustable line laser lighting system is arranged in the horizontal direction, and the adjustable line laser lighting system includes a centrally aligned laser installed along the optical axis from the light source to the image plane, a biconvex lens L4, a Powell prism L5, a biconcave lens L6, a biconvex lens L7, a double cemented lens U2 composed of a biconcave lens L8 and a biconvex lens L9, a meniscus lens L10, a meniscus lens L11, and a dichroic mirror F set at 45°.

[0035] The biconvex lens L4 forms the collimating lens group C, and the Powell prism D (L5) is an optical scribing prism, which can optimize the laser beam to be scribed into a straight line with uniform light density, good stability and good linearity after passing through. Its scribing mode is better than that of the cylindrical lens, and can eliminate the central hot spot and faded edge distribution of the Gaussian beam. The biconcave lens L6, the biconvex lens L7, the biconcave lens L8, the biconvex lens L9, the meniscus lens L10 and the meniscus lens L11 form the image telecentric system, which is the zoom lens group E. The dichroic mirror F is shared by the visible light Kohler illumination system and the adjustable line laser illumination system.

[0036] When in use, the laser emits a laser with a wavelength of 425nm. The collimating lens group C collimates the laser to make it parallel light. The Powell prism D (L5) is an optical scribing prism. Figure 4 In the X plane, the Powell prism D (L5) diverges the light, and then passes through the zoom lens group E, and the light is imaged on the image plane G through the dichroic mirror F; refer to Figure 5 In the Y plane, the light collimated by the collimating lens group C enters the zoom lens group E through the Powell prism D (L5) for focusing, and is imaged on the image plane G through the dichroic mirror F, so that the laser beam is finally imaged on the image plane G as a linear spot. At the same time, the zoom lens group E can change the focal length to adjust the spot size on the image plane G, thereby providing a "one"-shaped line laser illumination with uniform light density, good stability, good linearity and adjustable spot size. At the same time, it can provide a large amount of energy and can also be used to excite fluorescence for detecting special materials. Figure 6 is a diagram of each field of view of the adjustable line laser illumination system in the embodiment of the present application, referring to Figure 6 The light spots in each field of view are linear and of the same size, which can achieve linear uniform illumination, verifying the effect of the adjustable linear laser illumination system.

[0037] In a specific embodiment, the positions of the biconcave lens L8, the biconvex lens L9, the meniscus lens L10 and the meniscus lens L11 are fixed, the relative position between the biconcave lens L6 and the biconvex lens L7 is fixed and can be moved along the optical axis, and the focal length of the zoom lens group E is changed by moving L6~L7 back and forth along the optical axis and changing the relative positions of L6~L7 and L8~L11, so that the size of the linear spot projected on the image plane G can be adjusted within a certain range.

[0038] In a specific embodiment, each lens of the condenser lens group A, the achromatic lens group B, the collimator lens group C, the Powell prism D, and the zoom lens group E is a spherical lens. Spherical lenses are easy to manufacture in batches and stably, and have low costs.

[0039] The present application realizes the combination of visible light illumination and high-energy line laser illumination, which can be applied to industrial line scan lenses, and provides two kinds of high-brightness and uniform illumination for imaging under motion conditions of line scan cameras. In addition, visible light illumination or line laser illumination can be freely switched according to different features of the detected products to meet the detection requirements and realize product detection.

[0040] The above describes the specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0041] In the description of the present application, it should be understood that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The wording 'comprising' does not exclude the presence of elements or steps not listed in the claims. The wording 'one' or 'an' preceding an element does not exclude the presence of a plurality of such elements. The simple fact that certain measures are recorded in mutually different dependent claims does not indicate that a combination of these measures cannot be used for improvement. Any reference symbols in the claims should not be interpreted as limiting the scope.

Claims

1. An illumination system combining visible light illumination and adjustable line laser illumination, characterized in that: The invention comprises a visible light Kohler illumination system and an adjustable line laser illumination system. The visible light Kohler illumination system comprises an LED light source, a condenser lens group A, an achromatic lens group B and a dichroic mirror F in sequence along the optical axis from the light source to the image plane. The adjustable line laser illumination system comprises a laser, a collimating lens group C, a Powell prism D, a zoom lens group E and the dichroic mirror F in sequence along the optical axis from the light source to the image plane. The dichroic mirror F is arranged at the intersection of the optical paths of the visible light Kohler illumination system and the adjustable line laser illumination system. Visible light and laser are respectively reflected and transmitted by the dichroic mirror F and are imaged on the same image plane G.

2. According to claim 1, the lighting system combining visible light lighting and adjustable linear laser lighting is characterized in that: The condenser lens group A includes a meniscus lens L1 with positive focal power; the achromatic lens group B includes a double cemented lens U1 composed of a double concave lens L2 and a double convex lens L3.

3. The illumination system combining visible light illumination and adjustable linear laser illumination according to claim 1, characterized in that: The collimating lens group C includes a biconvex lens L4 in sequence, and the zoom lens group E includes a biconcave lens L6, a biconvex lens L7, a double cemented lens U2 composed of a biconcave lens L8 and a biconvex lens L9, a meniscus lens L10 and a meniscus lens L11 in sequence.

4. The illumination system combining visible light illumination and adjustable linear laser illumination according to claim 3, characterized in that: The positions of the biconcave lens L8, the biconvex lens L9, the meniscus lens L10 and the meniscus lens L11 are fixed, and the relative positions of the biconcave lens L6 and the biconvex lens L7 are fixed and can move along the optical axis.

5. The illumination system combining visible light illumination and adjustable linear laser illumination according to claim 1, characterized in that: The visible light Kohler illumination system is arranged in a vertical direction, the adjustable line laser illumination system is arranged in a horizontal direction, and the dichroic mirror F is arranged at 45 degrees.

6. The illumination system combining visible light illumination and adjustable linear laser illumination according to claim 5, characterized in that: The dichroic mirror F transmits light with a wavelength of 430 nm or less, and reflects light with a wavelength of 430 nm or more.

7. The illumination system combining visible light illumination and adjustable linear laser illumination according to claim 6, characterized in that: The laser wavelength emitted by the laser is 425nm.

8. The illumination system combining visible light illumination and adjustable linear laser illumination according to claim 1, characterized in that: Each lens of the condenser lens group A, the achromatic lens group B, the collimating lens group C, the Powell prism D, and the zoom lens group E is a spherical lens.

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