KR102125288B1 - 3d printer - Google Patents

Abstract

The 3D printer according to the present invention includes an extruder having a nozzle, a bed on which a designed sculpture is formed, a lighting unit provided on the top of the bed and installed to be inclined toward the bed, a camera imaging the top of the bed, It includes a controller for controlling the operation and operation of the extruder and the camera, a printing area is set in the center of the bed, a forbidden area is set at the edge, and a spaced area and a pre-printed area between the printing area and the forbidden area. An area is set, and the pre-printed area is pre-printed with a first layer structure and a second layer structure formed on the first layer structure, wherein the length of the first layer structure is greater than the length of the second layer structure. Long formed, the camera is installed on the upper side of the pre-printing area, and images the pre-printed sculpture and outputs an image signal, and the controller is based on the width of the pre-printed sculpture that is stacked on the pre-printed area. An image processing unit for determining a printing time point, and the image processing unit is a signal conversion unit for converting an image signal to a grayscale signal, and an outline for detecting the edge lines of the first and second layer structures from the grayscale signal. A comparison value by comparing the widths of the edge lines of the detected first layer structure and the second layer structure, and a region correction unit that acquires a boundary line inside the edge line and adds an edge line according to the selective light emission of the lighting unit An outline comparison unit for calculating and an outline determination unit for outputting the starting signal for printing when the comparison value calculated from the outline comparison unit is within a preset reference value range, wherein the pre-printing is performed before the main printing, The pre-printing area is repeatedly performed until the main printing start signal of the outline determining unit is output.

Description

3D printer with pre-printing function {3D PRINTER}

The present invention relates to a 3D printer, and more particularly, to a structure of a 3D printer capable of finding a time point at which proper lamination is performed by performing pre-printing prior to this printing.

The extruder of a 3D printer is a device that discharges printing materials. As a material to be introduced into the extruder, a solid material may be mainly used, but a liquid material or a powder material may be used. These materials are melted in an extruder and finally discharged to a nozzle, which is discharged in a molten state by heating.

The molding designed by the computer system may further perform a post-treatment process for visual effect, but it is also possible to control the physical properties of the discharged material by adding an additive to the extruder. However, when an additive is added to the discharge, the melting state may be changed according to the characteristics of the additive, and the molten state may be a dilute state that is not suitable for lamination.

3D printer normal output verification device of published patent publication No. 10-2017-0010140 Low-melting material printing method of 3D printer disclosed in Korean Patent Publication No. 10-2016-0147633 Photo-curable 3D printer of published patent publication No. 10-2014-0195073 and a method for measuring and correcting the amount of light deviation therefrom 3D printer extruder including the integral nozzle of published patent publication No. 10-2017-0010624

An object of the present invention is to provide a 3D printer that can be printed in a state in which the moldings stacked on the bed have suitable physical properties even when different printing materials are used.

In addition, it is an object of the present invention to provide a 3D printer capable of preventing lamination defects during printing by performing a pre-printing process even when an additive is added to an extruder.

The problems to be solved of the present invention are not limited to the problems mentioned. Other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

The 3D printer according to the present invention includes an extruder having a nozzle, a bed on which a designed sculpture is formed, a lighting unit provided on the top of the bed and installed to be inclined toward the bed, a camera imaging the top of the bed, It includes a controller for controlling the operation and operation of the extruder and the camera, a printing area is set in the center of the bed, a forbidden area is set at the edge, and a spaced area and a pre-printed area between the printing area and the forbidden area. An area is set, and the pre-printed area is pre-printed with a first layer structure and a second layer structure formed on the first layer structure, wherein the length of the first layer structure is greater than the length of the second layer structure. Long formed, the camera is installed on the upper side of the pre-printing area, and images the pre-printed sculpture and outputs an image signal, and the controller is based on the width of the pre-printed sculpture that is stacked on the pre-printed area. An image processing unit for determining a printing time point, and the image processing unit is a signal conversion unit for converting an image signal to a grayscale signal, and an outline for detecting the edge lines of the first and second layer structures from the grayscale signal. A comparison value by comparing the widths of the edge lines of the detected first layer structure and the second layer structure, and a region correction unit that acquires a boundary line inside the edge line and adds an edge line according to the selective light emission of the lighting unit An outline comparison unit for calculating and an outline determination unit for outputting the starting signal for printing when the comparison value calculated from the outline comparison unit is within a preset reference value range, wherein the pre-printing is performed before the main printing, The pre-printing area is repeatedly performed until the main printing start signal of the outline determining unit is output.

The outline detection unit of the 3D printer according to the present invention detects an edge line using a closed curve detection method.

The video signal according to the present invention is composed of a first video signal that is captured after the first layer of the printed object, and a second video signal that is captured after the second layer of the formed object on the first layer of the sculpture, The edge detection unit of the image processing unit matches the edge lines of the ends of the first layer structures included in the first image signal and the edge lines of the ends of the first layer structures included in the second image signal to match the first layer and the second layer. It is configured to compare the edge line width of the sculpture.

According to the present invention, even when different printing materials are used, it is possible to print in a state in which the moldings laminated on the bed have suitable physical properties.

In addition, even when the additive is administered to the extruder, a pre-printing process may be performed to prevent lamination defects in advance during the main printing.

1 shows a 3D printer according to the present invention.
2 shows a virtual area set on a bed according to the present invention.
3 shows an image processing unit according to the present invention.
4 shows a printing method according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. For convenience of description, elements illustrated in the drawings may be exaggerated, omitted, or schematically represented.

1 shows a 3D printer according to the present invention.

The 3D printer according to the present invention includes an extruder 100 equipped with a nozzle, a bed 200 on which a designed object is printed, an illumination unit 300 dimming so as to be inclined toward the bed, and imaged toward the top of the bed It includes a camera 400, and a controller 500 for driving and operating the extruder and the camera.

A printing material is introduced into the extruder 100. The printing material may be a wire-shaped filament, and the material of the filament may be ABS, PLA, and the like. As another embodiment, the printing material may be a liquid material or powder particles. The liquid material may be silicon, and the powdery material may be chocolate particles.

Additionally, in the present invention, an additive capable of controlling physical properties may be further added to the printing material in addition to the printing material. The additive may be a coloring agent, an emulsifying agent, a curing agent, and the like.

A nozzle is provided at the bottom of the extruder, and the printing material is discharged to the nozzle in a molten state. In order to melt the printing material, a heater may be further provided on the body of the extruder including the nozzle.

As an embodiment, a cooling material may be further provided to prevent the printing material and the additive from being melted in advance when the input material, that is, the printing material or the additive is added.

The bed 200 is shaped as a molded material designed by the molten material discharged from the extruder. A heater may be further provided under the bed.

2 shows a virtual area set on a bed according to the present invention.

In the bed according to the present invention, a printing area AA is set in the center portion, a forbidden area DD is set in the edge portion, and a separation area BB and a pre-printing area CC are provided between the printing area and the forbidden area. Is set. The pre-printing area is adjacent to the forbidden area, and the spaced area is adjacent to the printing area.

The printing area AA is an area in which main printing is performed, and the pre-printing area CC is an area in which pre-printing is performed. The pre-printing is performed prior to the main printing.

The pre-printing according to the present invention may be formed in a linear shape having a predetermined length, and these structures may be a basic structure and a laminated structure pre-printed on a bed. Here, the basic sculpture is a first layer sculpture preprinted on a bed, and the laminate sculpture may be a sculpture in which a second layer sculpture is stacked on top of the first sculpture. As an embodiment, the length of the first layer structure may be pre-printed longer than the length of the second layer structure.

The lighting unit 300 is dimmed to be inclined toward the bed. It is possible to easily detect the outline of the pre-printed sculpture due to the light emission of the lighting unit. As an embodiment, the lighting unit selectively illuminates the basic sculpture and the laminated sculpture during pre-printing. As an example, the basic sculpture may emit light after being pre-printed and may not emit light after the second layer sculpture is pre-printed. Conversely, the basic sculpture may not emit light after pre-printing and emit light after the laminated sculpture is pre-printed. . Here, a color different from the color of the pre-printed molding may be selected as the light emission color of the lighting unit. As another embodiment, after the basic sculpture is printed, it may emit light in a first color, and after the laminated sculpture is printed, it may emit light in a second color. As an embodiment, a color different from the color of the sculpture may be selected as the first color and the second color.

The camera 400 is installed above the pre-printing area. The camera captures a layered sculpture printed in the pre-printed area. According to the present invention, an image captured from a camera can image a layered sculpture printed on a pre-printed area.

The controller 500 controls the driving of the extruder, the heating of the bed, the lighting of the lighting unit, and the imaging of the camera, and detects the printing time point viewed from the captured image signal. The controller according to the present invention further includes an image processing unit for image processing the captured image signal. The image processing unit detects a difference in width between the first layer structure and the second layer structure preprinted on the preprinting area from the image signal and outputs the present printing signal.

3 shows an image processing unit of the controller according to the present invention.

The image processing unit 510 of the controller according to the present invention includes a signal conversion unit 511, an outline detection unit 512, an area correction unit 513, an outline comparison unit 514, and an outline determination unit 515. do.

The signal conversion unit 511 converts the input video signal to a grayscale signal. When the input video signal is a YUV signal, a Y signal is extracted. As another embodiment, when the input video signal is an RGB signal, the RGB signal is converted into a YUV signal according to the following conversion equation, and a Y signal is extracted from the converted YUV signal. Here, the image signal includes a first image signal S1 that captures the basic sculpture and a second image signal S2 that captures the laminated sculpture.

Y = (0.257R) + (0.504G) + (0.098B) +16

U =-(0.148R)-(0.291G) + (0.439B) + 128

V = (0.439R)-(0.368G)-(0.071B) + 128

The outline detector 512 detects an edge line from a grayscale signal. As an embodiment, an edge line may be detected using a detection method of a closed curve in a grayscale signal.

The area correction unit 513 corrects the edge line information of the input image. The correction of the edge line information is performed based on the image signal captured according to the selective light emission of the lighting unit. Inside the edge line, there may be areas having at least one or more different color information. For example, if there is an area having two color information in one edge line, a boundary line is acquired and an edge line is added.

The outline comparator 514 calculates a comparison value between the edge line of the first layer structure and the edge line of the second layer structure.

As an embodiment, the edge line of the first layer structure and the edge line of the second layer structure may be based on the position value of the end of the first layer structure. The laminated structure is composed of a first layer structure and a second layer structure, and the length of the first layer structure is longer than the length of the second layer structure. As an embodiment, both ends of the first layered structure are formed outside the opposite ends of the second layered structure. The first image signal and the second image signal may be matched by matching the end position value of the first layer structure included in the first image signal and the end position value of the first layer structure included in the second image signal.

According to the present invention, a comparison value is calculated by comparing the width of the edge line of the first layer structure and the width of the edge line of the second layer structure.

The outline determination unit 515 outputs the printing start signal when the comparison value calculated from the outline comparison unit is within a preset reference value range.

Hereinafter, printing using the 3D printer according to the present invention configured as described above will be described.

3 shows a printing method according to the present invention.

The printing method according to the present invention comprises the steps of performing pre-printing on the edge area spaced a predetermined distance from the printing area (S100), checking the lamination of the pre-printing (S200), and performing the main printing on the printing area. It includes a step (S300).

The bed of the 3D printer is made in a square shape, and the designed sculpture is stacked on top of the bed. The printing area where the printed object is printed is formed at the center of the bed, and the edge area of the bed is not printed. In the present invention, the pre-printing area is set at an edge area spaced apart from the printing area that is set as the printing area.

When the molten material discharged from the nozzle maintains a constant viscosity, normal lamination can be achieved. This viscosity is determined by the melting state of the material, printing temperature, and the like. The molten material discharged initially is difficult to maintain the required level of viscosity. Accordingly, it is necessary to check whether lamination is normally performed. In particular, in the case of a method in which a printing material and an additive are mixed inside and discharged through a nozzle, the present printing must be performed after an appropriate mixing state is achieved. In the present invention, a pre-printing step is performed to check whether the viscosity of the molten material discharged initially reaches a certain level of viscosity.

In the step of performing the pre-printing, a first layer structure having a predetermined length is formed in an edge region, and then a second layer structure is formed on the first layer structure. Here, the first layer structure is called a basic structure, and the second layer structure is formed on top of the first layer structure. On the other hand, the speed and discharge amount of printing are set to be the same as the speed and discharge amount to be performed in this printing.

Subsequently, a process of confirming the molding result laminated by pre-printing is performed. The confirmation process can be manually checked by the operator and determined whether to perform the present printing, but in the present invention, detection is performed using a camera. The camera is installed on the upper portion of the pre-printing area so as to check the edge line width of the first and second layer structures by imaging from the top to the bottom. At this time, the lighting unit may selectively illuminate the basic sculpture and the laminated sculpture.

The controller according to the present invention detects the difference in the edge line width of the first layered structure and the second layered structure from the image captured from the sensor. Meanwhile, the first layer structure is formed by directly contacting the top of the bed, and the second layer structure is stacked on top of the first layer structure, so that the printing environment of the first layer structure and the second layer structure is different. In addition, the second layer structure has a more stable discharge condition than the first layer structure. Accordingly, it is possible to confirm whether the discharge conditions are satisfied according to whether the second layer structure is laminated.

First, the controller according to the present invention detects the width of the first layer structure and the second layer structure and compares the width of the first layer structure and the second layer structure. If the edge line of the second layer structure is wider than the edge line of the second layer structure, it is determined that the environmental conditions to perform the main printing have not yet been reached, and another first layer structure and the second layer structure are placed in the neighboring pre-printing area. And performing a lamination process, and this process may be repeatedly performed until the present printing start signal MPS is output.

If the width of the image captured after laminating the second layer structure on top of the first layer structure is the same value as the first layer structure or a value within a preset allowable range, it means that the present printing is ready.

Subsequently, this printing is performed. The printing is performed in a preset printing area. Since the printing area and the pre-printing area are spaced apart at predetermined intervals, the completed sculpture is independent from the result of pre-printing.

The method for performing pre-printing according to the present invention can prevent printing defects when printing is performed using a printing material having a physical property having low viscosity, such as chocolate and silicone.

As described above, the present invention has been described in detail through specific embodiments, but the present invention is not limited to the above embodiments, and various modifications can be made by those skilled in the art within the scope of the technical spirit of the present invention.

100: extruder
200: bed
300: lighting unit
400: camera
500: controller
510: image processing unit
511: signal converter
512: outline detection unit
513: area correction unit
514: outline comparison unit
515: outline judgment unit
AA: printing area
BB: separation area
CC: Pre-printing area
DD: Prohibited area

Claims (3)

The extruder with the nozzle, the bed on which the designed sculpture is formed, the lighting part provided on the top of the bed and installed to be inclined toward the bed, the camera imaging the top of the bed, driving the extruder and the camera, and It includes a controller to control the operation,
A printing area is set at the center of the bed, a forbidden area is set at the edge of the bed, and a separation area and a pre-printing area are set between the printing area and the forbidden area,
In the pre-printing region, a first layer structure and a second layer structure formed on the first layer structure are preprinted, and the length of the first layer structure is longer than that of the second layer structure,
The camera is installed on the upper side of the pre-printed area, and images the pre-printed sculpture and outputs an image signal.
The controller includes an image processing unit that determines a printing time point of the printing area based on the width of the pre-printed sculpture that is stacked on the pre-printing area,
The image processing unit includes a signal conversion unit that converts an image signal to a grayscale signal, an outline detection unit that detects edge lines of the first and second layer structures from the grayscale signal, and the edge line according to the selective light emission of the illumination unit. An area comparator for acquiring an inner boundary line and adding an edge line, an outline comparator for comparing the widths of the detected edge lines of the first and second layer structures, and calculating a comparison value, and comparing the outline When the comparison value calculated from the unit is within a preset reference value range, an outline determining unit for outputting the starting fringing signal is included.
The edge detection unit of the image processing unit detects an edge line using a closed curve detection method,
The video signal is composed of a first video signal generated after the first layer sculpture is printed, and a second video signal generated after the second layer sculpture is formed on the first layer sculpture, and the image processor The edge detection unit of the first and second layer structures is matched by matching the edge lines of the ends of the first layer structures included in the first image signal and the edge lines of the ends of the first layer structures included in the second image signal. Compare line widths,
The pre-printing is performed before the main printing, the 3D printer characterized in that it is repeatedly performed in the pre-printing area until the main printing start signal of the outline determining unit is output.
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