A visual and dispensing head offset calibration device of a dispensing machine

Abstract

The utility model discloses a visual and point gum head offset calibration device of point gum machine, and the device includes base, calibration board fixed on base, point gum head fixed subassembly and camera. The calibration board is etched with accurate positioning calibration characteristic pattern, point gum head fixed subassembly detachably installed in the lower extreme of point gum head, and the lower extreme is equipped with the reference needle point coaxial with point gum head. When calibrating, first drive point gum head to make reference needle point aim at calibration characteristic pattern center, and record first position coordinate, then drive camera to the same pattern and carry out shooting identification, obtain second position coordinate, and the accurate offset of visual and point gum head is obtained through the coordinate difference value calculation. The utility model adopts the mode that mechanical type alignment and visual identification are combined, and the structure is simple, and the calibration process is quick, accurate, and effectively solves the problem that traditional manual calibration is low in efficiency and poor in precision.

Description

Technical Field

[0001] This utility model relates to the field of dispensing machine technology, specifically to a vision and dispensing head offset calibration device for a dispensing machine. Background Technology

[0002] Vision dispensing machines are widely used in fields such as precision electronics and semiconductor packaging. Their workflow typically involves the vision camera first capturing the dispensing location on the product, and then the dispensing head moving to that location to perform the dispensing. Since the camera and dispensing head are usually mounted side-by-side, there is a physical spatial offset. Therefore, the offset between the camera coordinate system and the dispensing head coordinate system must be precisely calibrated; otherwise, the dispensing position will be inaccurate.

[0003] Existing calibration methods typically employ manual techniques: an operator moves the dispensing head to a reference point (such as a crosshair), records the position, then uses a camera to identify that reference point, and calculates the offset. This method has the following drawbacks: Inefficient: The process is cumbersome, relies on manual operation, and is time-consuming.

[0004] Unstable accuracy: Manual alignment and reading are prone to subjective errors, resulting in poor repeatability.

[0005] Complex operation: Requires a high level of technical skill from the operators.

[0006] Therefore, there is an urgent need for a device that can automatically, quickly, and with high precision complete the visual and dispensing head offset calibration. Utility Model Content

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a dispensing machine vision and dispensing head offset calibration device with simple structure, high calibration efficiency and high precision.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is: a vision and dispensing head offset calibration device for a dispensing machine, the innovation of which lies in comprising: Base; A calibration plate is fixedly installed on the upper surface of the base, and the calibration plate is provided with at least one calibration feature pattern for precise positioning; A dispensing head fixing assembly is used to be detachably installed on the lower end of the dispensing head of a dispensing machine. The lower end of the assembly is provided with a reference needle tip, and the axis of the reference needle tip coincides with the axis of the dispensing head. A camera, mounted on the vision module of the dispensing machine, is used to capture the calibration feature pattern; Specifically, by driving the dispensing head to align the reference needle tip with the center point of the calibration feature pattern, a first position coordinate in the dispensing head coordinate system is obtained; by driving the camera to capture and recognize the same calibration feature pattern, a second position coordinate in the camera coordinate system is obtained; by calculating the difference between the first position coordinate and the second position coordinate, the offset between the visual field and the dispensing head is obtained.

[0009] Furthermore, the calibration feature pattern is one of a cross-shaped mark, a circular mark, or a concentric ring mark.

[0010] Furthermore, the calibration plate is a glass plate or a metal plate, the surface of which is frosted or coated with a matte layer.

[0011] Furthermore, the dispensing head fixing assembly includes a sleeve and a needle bar; the sleeve is used to fit onto the end of the dispensing head and is fixed by a set screw; the needle bar is coaxially mounted on the lower end of the sleeve, and the reference needle tip is located at the center of the end of the needle bar; the needle bar and the sleeve are coaxially arranged so that the axis of the reference needle tip coincides with the axis of the dispensing head after installation.

[0012] Furthermore, the reference needle tip is conical or pyramidal in shape, with a tip radius of curvature of less than 0.1 mm.

[0013] Furthermore, the calibration plate is provided with multiple sets of calibration feature patterns arranged in an array.

[0014] Furthermore, the device is communicatively connected to the motion drive mechanism of the dispensing machine; the motion drive mechanism is used to drive the dispensing head to align the reference needle tip with the calibration feature pattern, and to drive the camera to capture the calibration feature pattern.

[0015] The beneficial effects of this utility model after adopting the above structure are as follows: This invention requires no manual intervention. After the device is installed, the dispensing machine can automatically complete the process of aligning the reference needle tip and taking a picture with the camera. The whole process can be completed in a few minutes, which greatly improves the efficiency of equipment setup and line change, and the calibration efficiency is high.

[0016] This invention uses a mechanical reference needle tip to directly align with the physical mark, avoiding errors caused by human visual judgment; the high-precision calibration plate and needle tip ensure the accuracy of position information, with a calibration repeatability of ±0.005mm, resulting in high calibration accuracy.

[0017] This utility model has a simple structure and low cost. The device mainly consists of a base, a calibration plate and detachable fixing components. It has a compact structure, low manufacturing and maintenance costs, and is easy to install and promote on existing equipment.

[0018] This invention is applicable to various models of vision dispensing machines. It only requires replacing the fixing sleeve that matches the dispensing head, making it highly versatile and widely applicable. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a top view of the calibration plate in this utility model.

[0020] Explanation of reference numerals in the attached figures: 1-Base, 2-Calibration plate, 3-Calibration feature pattern, 4-Dispensing head fixing assembly, 41-Sleeve, 42-Set screw, 43-Needle bar, 44-Reference needle tip, 5-Dispensing head, 6-Camera. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model.

[0023] like Figure 1-2 As shown, this utility model provides a vision and dispensing head offset calibration device for a dispensing machine, including a rectangular metal base 1, which is fixed to the worktable of the dispensing machine by screws. A glass calibration plate 2 is fixed on the upper surface of the base 1, and the surface of the calibration plate 2 is frosted to prevent reflection. A clear cross-shaped calibration feature pattern 3 is etched on the calibration plate 2.

[0024] The dispensing head fixing assembly 4 consists of a sleeve 41 and a needle bar 43. The inner diameter of the sleeve 41 is tightly fitted with the outer diameter of the end of the dispensing head 5 and is locked in place by a set screw 42. The needle bar 43 is coaxially mounted on the lower end of the sleeve 41, and its end is machined with a conical reference needle tip 44 with a very small radius of curvature.

[0025] The inner hole of the sleeve 41 is precisely fitted with the outer circle of the end of the dispensing head 5. The lower end interface of the needle bar 43 and the sleeve 41 adopts a high-precision coaxial connection structure (such as thread, press fit, etc.) and through precision machining, it is ensured that after assembly, the geometric axis of the reference needle tip 44 is highly coincident with the theoretical working axis of the dispensing head 5, and its coaxiality error should be less than 0.01mm.

[0026] When in operation, this calibration device uses the inherent motion control system of the dispensing machine (i.e., X, Y, Z axis drive motors and slides) to precisely drive the dispensing head 5, which is equipped with the dispensing head fixing assembly 4, and the camera 6. It is designed to cooperate with the motion control system to achieve automatic calibration.

[0027] The calibration process is as follows: Installation device: Fix the base 1 on the workbench and install the dispensing head fixing assembly 4 onto the dispensing head 5.

[0028] Needle tip alignment: Manually or automatically control the Z-axis slide 7 of the dispensing machine to drive the dispensing head 5 to move, so that the reference needle tip 44 slowly descends until its tip is visually (can be initially observed with the aid of a high-magnification magnifying glass) precisely aligned with the center of the cross mark on the calibration plate 2. At this time, record the current position coordinates (X1, Y1) in the dispensing head motion control system.

[0029] Camera takes a picture: Lift the dispensing head 5, drive the camera 6 mounted on the dispensing machine to move above the cross mark, perform automatic focusing and take a picture, and use the image processing algorithm to identify the pixel coordinates of the center of the cross mark in the camera coordinate system and convert them into mechanical coordinates (X2, Y2).

[0030] Calculate the offset: Calculate the difference between the two coordinates: ΔX = X2 - X1, ΔY = Y2 - Y1. This (ΔX, ΔY) is the offset between the vision camera 6 and the dispensing head 5. After inputting it into the dispensing machine control system, precise synchronization between visual positioning and dispensing execution can be achieved.

[0031] This utility model adopts a detachable modular design, and can be installed and used only when calibration is required, without affecting the normal dispensing function of the dispensing head.

[0032] Before calibration, first ensure that the inside of the dispensing head is free of glue and clean. Then, install the dispensing head fixing assembly 4 onto the end of the dispensing head 5 using the sleeve 41 and the set screw 42. After completing the collection and calculation of calibration data, loosen the set screw 42 and remove the dispensing head fixing assembly 4 from the dispensing head 5 to restore the normal dispensing operation of the dispensing machine.

[0033] The calibration device of this invention is an independent tool that is only installed during calibration and disassembled after use. It does not interfere with the normal production process of the dispensing machine and will not cause blockage or contamination of the dispensing head.

[0034] The needle bar 43 and the reference needle tip 44 are either integrally formed or detachable.

[0035] As an integrally formed structure, the needle bar 43 and its end reference needle tip 44 are integrally ground from a cemented carbide material. This structure can maximize the coaxiality of the two, thereby obtaining the highest calibration accuracy.

[0036] As a detachable structure, the reference needle tip 44 can be a separate tungsten carbide needle tip, which is connected to the end of the needle bar 43 via a high-precision thread (or interference fit or bonding). This design allows for easy replacement after the needle tip wears out, reducing usage and maintenance costs.

[0037] The above description is only used to illustrate the technical solution of this utility model and is not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. A vision and dispensing head offset calibration device for a dispensing machine, characterized in that, include: Base; A calibration plate is fixedly installed on the upper surface of the base, and the calibration plate is provided with at least one calibration feature pattern for precise positioning; A dispensing head fixing assembly is used to be detachably installed on the lower end of the dispensing head of a dispensing machine. The lower end of the assembly is provided with a reference needle tip, and the axis of the reference needle tip coincides with the axis of the dispensing head. A camera, mounted on the vision module of the dispensing machine, is used to capture the calibration feature pattern; Specifically, by driving the dispensing head to align the reference needle tip with the center point of the calibration feature pattern, a first position coordinate in the dispensing head coordinate system is obtained; by driving the camera to capture and recognize the same calibration feature pattern, a second position coordinate in the camera coordinate system is obtained; by calculating the difference between the first position coordinate and the second position coordinate, the offset between the visual field and the dispensing head is obtained.

2. The vision and dispensing head offset calibration device for a dispensing machine according to claim 1, characterized in that: The calibration feature pattern is one of a cross-shaped mark, a circular mark, or a concentric ring mark.

3. The vision and dispensing head offset calibration device for a dispensing machine according to claim 1, characterized in that: The calibration plate is a glass plate or a metal plate, and its surface is frosted or coated with a matte layer.

4. The vision and dispensing head offset calibration device for a dispensing machine according to claim 1, characterized in that: The dispensing head fixing assembly includes a sleeve and a needle bar; the sleeve is used to fit onto the end of the dispensing head and is fixed by a set screw; the needle bar is coaxially mounted on the lower end of the sleeve, and the reference needle tip is located at the center of the end of the needle bar; the needle bar and the sleeve are coaxially arranged so that the axis of the reference needle tip coincides with the axis of the dispensing head after installation.

5. The vision and dispensing head offset calibration device for a dispensing machine according to claim 1 or 4, characterized in that: The reference needle tip is conical or pyramidal in shape, with a tip radius of curvature of less than 0.1 mm.

6. The vision and dispensing head offset calibration device for a dispensing machine according to claim 1, characterized in that: The calibration plate is provided with multiple sets of calibration feature patterns arranged in an array.

7. The vision and dispensing head offset calibration device for a dispensing machine according to claim 1, characterized in that: The device is communicatively connected to the motion drive mechanism of the dispensing machine; the motion drive mechanism is used to drive the dispensing head to align the reference needle tip with the calibration feature pattern, and to drive the camera to take a picture of the calibration feature pattern.

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