TWI877795B - A kind of improved dihedral corner reflector array and its application in stereolithography method and apparatus. - Google Patents

Abstract

This invention is an improvement to the existing Dihedral Corner Reflector Array (DCRA), so it does not generate ghost images, and we can uses the characteristics of the aerial display in stereolithography apparatus. It can greatly speed up the printing speed and increase its accuracy. Because of the application of the new method, many photocuring solvent can be saved, and the generation of residues can also be avoided. After improvement, The printing time can shorten to be only 1/5 of the traditional method.

Description

An improved double-angle reflector array and its application in photocuring lamination manufacturing equipment and method

Since its invention, the existing dual-angle reflector array (DCRA) has been mostly used in floating projection display. Part of the reason is that it produces ghost images, which are difficult to eliminate. The present invention analyzes the causes of its generation from a theoretical perspective and proposes effective methods to prevent and control it. Then, using its floating projection characteristics, it is applied to the light-curing (layer-by-layer manufacturing equipment) 3D printer system, which can greatly speed up its printing speed and increase its accuracy. The current light-curing 3D printer operates very slowly. It often takes 2 to 3 hours to print a workpiece, which makes people anxious. Printing often fails in the middle and cannot work stably, which makes people hesitate. The reason is that ordinary light-curing 3D printers are exposed in close contact with the LCD. After each exposure, the workpiece must be deglazed in the exposure area to prevent the workpiece from sticking and allow fresh solvent to flow into the exposure area. The deglazing process causes the solvent to shake, resulting in very unstable workpiece quality; the sticky residue after printing is even more troublesome, and the consumables need to be replaced every time. The double-angle reflector array after improving the ghosting effect can float in the solvent, allowing for fast and continuous printing without sticking problems, so that the entire printing time can be shortened to only 1/5 of the traditional method.

In 2006, Chuan Cong published a paper in SPIE (International Society of Photoelectric Engineering) on the invention of the floating projection device. By using the double-angle reflector array (DCRA), a high-quality image floating in the air can be formed as shown in Figure 1. The entire system includes an object space 110, a DCRA element 100 and an imaging space 120. The object space 110 and the DCRA element 100 have a 45° angle, the DCRA element 100 and the imaging space 120 have a 45° angle, and the object space 110 and the imaging space 120 have a 90° angle with each other. Although the actual finished product still has the disadvantages of ghosting and low light utilization efficiency; its resolution is still far better than the effect made by using traditional optical elements in the past. After years of improvement, the floating projection display made by it has been successfully used in business. However, the ghost removal is still not perfect enough, which limits its other uses.

Regarding the ghosting problem of DCRA, after a large number of experimental results, it can be found that only a part of the light from the object side becomes effective imaging light after passing through DCRA. In summary, as shown in Figure 2, on the YZ plane, there is a part of light 140 greater than 45 degrees. This part of the light cannot be incident on any side of the double-angle reflective surface in DCRA; it becomes stray light and is absorbed by the black light layer in DCRA and disappears. There is light 150 less than 45 degrees, but it can be incident on one side of the double-angle reflective surface in DCRA, but it cannot be incident on the other side of the double-angle reflective surface in DCRA. This part of the light will be imaged in the imaging area and become ghost light; there is light 160 less than 45 degrees, but it can be incident on both sides of the double-angle reflective surface in DCRA continuously. This part of the light will form a clear image, which is the light we need; these three parts of light are mixed together to become the image we see; in the past, some papers mentioned that changing the angular distribution of the light source can reduce the ghost situation, but when the intensity of the light source increases, the human eye can still perceive its existence. The present invention will completely eliminate ghosts from the perspective of theory and improved design, and expand its application in other imaging optics.

Regarding the application of DCRA as an imaging element in other fields; since its invention, DCRA has attracted the attention of many people due to its excellent resolution characteristics, but the annoying ghost problem makes it difficult to expand its application; if ghosting can be eliminated, DCRA will have more advantageous applications than traditional imaging optical elements; such as imaging lenses used for exposure and development. In order to eliminate spherical aberration and distortion, traditional imaging lenses must stack a lot of lens groups to eliminate aberrations, and precise displacement control is required to obtain large-area precision imaging; if it is added that it must be imaged in an immersion situation, the working distance of the lens must be sufficient, which causes many difficulties to be overcome in lens design and manufacturing, and the cost is also extremely high. This invention takes a different approach, using the simplicity and high-resolution characteristics of DCRA to analyze and change the design from a theoretical level to eliminate ghosting. It also introduces the application of multi-layer manufacturing (3D printing).

DLP photocuring type multilayer manufacturing equipment, as shown in FIG. 3A and FIG. 3B, is a DLP type photocuring type multilayer manufacturing equipment (hereinafter referred to as 3D printer) 200, which uses UV light 220 generated by a light bulb (or LED) to project the image on the chip 210 to the position 250 of the workpiece in the photocuring solvent tank 240 through the projection lens 220; the slice image is displayed. In the polymer photosensitive solution, the image is exposed and developed, and condensed into a shape. Then the lifting mechanism device 260 is moved to project the next layer of slices and expose and shape them. The disadvantage of this system is that as an optical magnifying lens, it will basically produce distortion aberration at the periphery, causing deformation of the workpiece; in terms of resolution quality, the center and the periphery are inconsistent; often the resolution of the central area is good, but the periphery will be deformed and blurred; in addition, as shown in Figure 3C, the edge beam 270 of the lens will change the concentration of the photocuring solvent in the case of wide angle, resulting in slight changes in the near and far imaging positions 280, 290, causing the size of the image to change. The wider the angle of the lens, the more serious the error. Therefore, the result of not being too wide-angle, resulting in the manufacturing area cannot be very large, and the price of high-quality optical imaging lenses is also extremely expensive and unacceptable.

LCD photocuring lamination manufacturing equipment, as shown in Figure 4A, Figure 4B is an LCD-type photocuring lamination manufacturing equipment (hereinafter referred to as 3D printer); using a single-color LCD panel 320 and a UV LED backlight panel 310; in the photocuring solvent tank 330, the slice screen is displayed, and the release film is exposed and condensed in a polymer photosensitive solution. The advantages of this method are that the manufacturing area can be relatively large, the resolution is high, and the center and periphery resolutions are average. The disadvantages are shown in Figure 4C, which shows that 300A, 300B, and 300C are three working states, close exposure, separation, and return to the positioning point. At the beginning, the elevator 350 controls the workpiece 340, and the release film 320 on the LCD is exposed in close contact, and the solvent is condensed to form. Then it is separated and the release film is torn (otherwise, the next layer of slices cannot be made). Wait for the new solvent to flow in, and then it is in close contact with the release film on the LCD again to expose and shape the next layer of slices. The role of the release film on the LCD panel is crucial here; for a three-dimensional workpiece with 400 slices, the release film must be able to withstand the tearing force of separation and leave no residue; (therefore, it often fails), and the release film becomes a consumable that must be replaced; quality is extremely critical. In addition, when using the release film, the system must be separated after the sliced picture is exposed, allowing the photosensitive solution to flow into the exposure area and waiting for the solution to settle; therefore, the speed is very slow; if the vertical moving bearing is unstable, the printed workpiece will be skewed and twisted. Therefore, although LCD-type light-curing 3D printers have lower costs, they are still considered low-end models; their printing quality and speed still need to be greatly improved.

Regarding the next generation of imaging components for 3D printing, based on the above, the necessary conditions for the next generation of imaging components for 3D printing are:

(1) It must have a sufficiently long working distance to be able to image in liquids

(2) It is best to use telecentric imaging, which means that a slight change in distance will not affect the image size.

(3) Capable of large-area imaging

(4) The cost of the imaging element should be low and the structure should not be too sensitive or complex. Based on the above conditions, the improved DCRA is the best candidate element.

The present invention analyzes the light path theory of the dual-angle reflector array (DCRA) and proposes a method to set up a forbidden area at the input light plane to limit the invalid light of the first reflection from entering the unit; (in practice, the forbidden area is painted black), so that the pure effective light of the second reflection can be extracted to eliminate ghosting. The present invention also proposes the mathematical relationship between imaging resolution and unit size through theoretical calculation, that is, if the desired resolution can be defined, the required unit size can be calculated accordingly. In addition, the present invention proposes a method to apply the dual-angle reflector array (DCRA) after ghosting is removed to an immersion exposure machine, and designs its structure. Furthermore, the present invention proposes a method of applying the dual-angle reflector array (DCRA) after ghost removal to photocuring laminated manufacturing (3D printer) and designs its structure. The new photocuring laminated manufacturing (3D printer) is more accurate than the traditional form, and because it can print continuously, the speed is relatively fast.

100: Double-angle reflector array (DCRA) plate

110: Object is at the display position

120: The image side's position in the floating projection display

130: DCRA Unit

140: Light that is at an angle of more than 45 degrees to the center axis can only hit one side of the double-angle reflector.

150: Light with an angle less than 45 degrees to the central axis can only hit one side of the double-angle reflector

160: Light with an angle less than 45 degrees with the central axis can hit both sides of the double-angle reflector.

170: Light rays with an angle less than 45 degrees with the central axis can hit the edge point G of the second surface of the double-angle reflector.

131: Where the light enters DCRA, point A on the GFEH plane

132: The first reflection of the light, point B

133: The first reflection of the light, point C

134: Where the light leaves DCRA, point D

130A: The projection of the light incident on one of the DCRA units at A’ on the ZX plane

130B: The projection of the light incident on one of the DCRA units at A’ on the ZX plane

130R: A DCRA unit with a positive incident angle of light

131R: The incident point A’ of the light in unit 130R

132R: The first reflection point B of the light in unit 130R

133R: The second reflection point C of the light in unit 130R

134R: The light exit point D in unit 130R

135R: The light enters the unit 130R and extends to the intersection point on the EH edge at A.

130L: A DCRA unit with a negative incident angle of light

131L: The incident point A’ of the light in unit 130L

132L: The first reflection point B of the light in unit 130L

133L: The second reflection point C of the light in unit 130L

134L: The light exit point D in unit 130L

135L: The light enters the unit 130L and extends to the intersection point on the EH edge at A.

136: DCRA unit close to the object plane, light incident end

137: DCRA unit close to the object plane, light emission end

138: The DCRA unit is close to the object plane, the prohibited line on the left side, the road to the left must be black, it is a prohibited area

139: The DCRA unit is close to the object plane, the prohibited line on the right side, the road to the right must be black, it is a prohibited area

161: Light incident point A’

162: The first reflection point of light B

163: The second reflection point of light C

164: Light emission point D

171: Light incident point A’

172: The first reflection point of light B

173: The second reflection point of light C

174: Light emission point D

180: Projection of the light path vector on the YZ plane

190: Projection of light path vector on ZX plane

200: A 3D printer using DLP as the main imaging element

210:DLP chip

220:DLP lighting system

230:DLP optical engine projection lens

240: Light-curing solvent tank

250: Printed workpiece

260: Lifting mechanism device

270: Edge beam of exposure projection

280: Due to the change in solvent concentration, the projection distance becomes longer, resulting in a larger imaging area

290: Due to the change in solvent concentration, the projection distance becomes shorter, resulting in a smaller imaging area

300: A 3D printer using LCD as the main imaging element

310: UVLED light source

320: LCD panel, covered with a layer of release film

330: Light-curing solvent tank

340: Printed workpiece

350: Lifting mechanism device

300A: Exposure molding of the workpiece and the release film on the LCD in close contact

300B: The release film on the workpiece and LCD is torn and separated

300C: The workpiece returns to the original position and is in close contact with the LCD, and the LCD displays the next slice layer screen

500: A 3D printer system using improved DCRA

510: Collimated UV light source

520: LCD panel without light source

530: Improved DCRA flat panel with black finish

540: Imaging position, where the light curing agent condenses

550: Light curing agent solvent tank

560: Finished workpiece of light curing

570: Workpiece clamping mechanism

500A: A schematic diagram of the initial printing stage using the improved DCRA in a 3D printer system

500B: A schematic diagram of a 3D printer system using the improved DCRA at a mid-printing stage

500C: A schematic diagram of the second printing stage using the improved DCRA in a 3D printer system

500D: A schematic diagram of a 3D printer system using the improved DCRA at the final printing stage

600R: When x > 0, the dotted line is the effective light range of secondary reflection

<1曲線範圍 610R: x > 0,

<1 Curve Range

)<

曲線範圍 620R: x > 0, 2-tan( x +

)<

Curve range

曲線範圍 630R: x >0, 0< x <

Curve range

600L: When x <0, the dotted line is the effective light range of secondary reflection

<1曲線範圍 610L: x <0,

<1 Curve Range

)<

曲線範圍 620L: When x <0, 2-tan( x +

)<

Curve range

<x<0曲線範圍 630L: x <0, -

<x<0 curve range

700: The result of combining 600L and 610L. At this time, -18.43 ° < x <18.43 °

<

曲線範圍之結果，此時-11.3°<x<11.3° 800: add 700

<

The result of the curve range is -11.3 ° < x <11.3 °

900: An immersion exposure system using DCRA

910: Collimated UV light source

920: LCD panel without light source

930:DCRA flat panel

940: Light-curing solvent tank

950: Light imaging surface of the workpiece

960: Workpiece clamping mechanism

Figure 1 Dual-corner reflector array (DCRA) system diagram

Figure 2 Schematic diagram of the classification of light entering DCRA

Figure 3A A schematic diagram of the front view of a 3D printer using DLP as the main imaging element

Figure 3B A 3D schematic diagram of a 3D printer using DLP as the main imaging element

Figure 3C Schematic diagram of a 3D printer using DLP as the main imaging element

Figure 4A Schematic diagram of the front view of a 3D printer using LCD as the main imaging element

Figure 4B A three-dimensional schematic diagram of a 3D printer using LCD as the main imaging element

Figure 4C Three working states of a 3D printer using LCD as the main imaging element

Figure 5A 3D schematic diagram of the path vector of light entering the DCRA unit

Figure 5B Schematic diagram of the YZ plane component of the path vector of the light entering the DCRA unit

Figure 5C Schematic diagram of the ZX plane component of the path vector of the light entering the DCRA unit

Figure 6 Schematic diagram of the ZX plane of light entering the DCRA unit at different positions

Figure 7 Schematic diagram of the light vector in the ZX plane, when the incident angle is positive

Figure 8 Schematic diagram of the solution range when the incident angle of the light is positive and the path is a single reflection and a double reflection

Figure 9 Schematic diagram of light vector in the ZX plane, when the incident angle is negative

Figure 10 Schematic diagram of the solution range when the incident angle of the light is negative and the path is a single reflection and a double reflection

Figure 11 Schematic diagram of the complete solution range for a single reflection and a double reflection path, regardless of whether the incident angle of the light is positive or negative.

Figure 12 After setting the P/W range and x range, the range diagram of the pure secondary reflection effective light solution can be obtained

Figure 13 After setting the P/W range and x range, the light path value curve of the pure secondary reflection effective light solution can be obtained

Figure 14 An immersion exposure system using DCRA

Figure 15 3D view of setting up a prohibited area on a DCRA unit

Figure 16A: Effective light entering and exiting the prohibited area on the left side of the DCRA unit near the object end

Figure 16B shows the DCRA unit near the object end, with invalid light entering and exiting the forbidden area on the left side.

Figure 17A: Effective light entering and exiting the prohibited area on the right side of the DCRA unit near the object end

Figure 17B shows the DCRA unit near the object end, with invalid light entering and exiting the prohibited area on the right side.

Figure 18: XZ plane view of partially blackening the DCRA array

Figure 19 A stereoscopic view of a 3D printer system using the improved DCRA

Figure 20A A side view of a 3D printer system using the improved DCRA

Figure 20B A front view of a 3D printer system using the improved DCRA

Figure 21 A schematic diagram of continuous printing using the improved DCRA in a 3D printer system

Optical Path Equation of DCRA

Below we use the optical path equation to analyze the effective light problem of DCRA and propose a solution; we consider that light has x, y, z vectors, such as Figure 5A is a three-dimensional diagram of the path of a light incident on DCRA and its corresponding coordinate system; the entry point is 130, point A, then hits the first reflection surface 140, point B, then hits the second reflection surface 150, point C, and finally exits from 160, point D. The entire light vector can be considered to be composed of the Y plane vector 170 in Figure 5B and the XZ plane vector 180 in Figure 5C. The XZ plane is a diamond-shaped area below the DCRA, refer to Figure 6 for the schematic diagrams 130A and 130B of the XZ plane positions of different light rays incident on the DCRA. Taking 130A as an example, the light enters from point 161, A’, reflects from point 162, B, reflects from point 163, C, and exits from point 164, D. Point A’B can be extended to the EH edge to find the intersection point A. Taking 130B as an example, the light enters from point 171, B’, reflects from point 172, B, reflects from point 173, C, and exits from point 174, D’. Point CD’ can be extended to the GH edge to find the intersection point D.

Below we analyze the optical path equation of the DCRA unit as follows: Assume that the starting point of the light entering the DCRA is A’, and it can be extended to point A on the EH line. The light first enters the EF reflective surface, and then encounters the FG reflective surface. (The same situation applies if it first enters FG and then encounters EF)

Assuming x is the angle between the light and the X-axis, we divide all the light rays passing through point A into two groups for discussion;

(1) The first group of light rays, as shown in Figure 7: The light rays enter from point 131R, A’ (extending to the EH edge to point 135R, A), are reflected from point 132R, B, are reflected from point 133R, C, and are emitted from point 134R, D.

Assumptions:

Here we assume that the side length of the rhombus EF = FG = GH = HE is W and AH is p .

Therefore, after entering the diamond area, the total length of the light leaving the diamond area after two reflections is: OPE ( x ) = AB + BC + CD ------------(3)

The condition for achieving reflection on both surfaces is CG > 0. (Here CG < 0 means that the light cannot encounter the second reflection surface)

Reflection twice condition

Here we deal with trigonometric functions to simplify the equation

The total optical path can be simplified as: AB = WT ₃ - pT ₃ -----------(18)

= W ( T ₂ - T ₃ )+ pT ₃ -------------(20)

Reflecting twice condition (13) can be rewritten as:

Combining (29) and (1)(2), we use graphical method to analyze the range of solutions for x as shown in Figure 8.

In Figure 8, 630R is represented by formula (1), 610R is represented by formula (2), and 620R is represented by formula (29)

(2) The second group of light rays is shown in Figure 9: At this time, the light rays enter from point 131R, A’ (extending to the EH edge to point 135R, A), reflect at point 132R, B, reflect at point 133R, C, and exit from point 134R, D.

The conditions for the two reflections at this time are:

Following the previous derivation method, we can derive the following formula:

，由以上方程式(2)及(30)(32)，可作圖如第10圖 We use the X coordinate to represent x (the angle between the light and the x-axis in the diamond area) and the Y coordinate to represent

, from the above equations (2) and (30)(32), we can draw a graph as shown in Figure 10

值及x值的範圍。 630L in Figure 10 is expressed by equation (30), 610L is expressed by equation (2), and 620L is expressed by equation (32). The combined results of Figures 8 and 10 are shown in Figure 11. The range of the combined result x is 700. The dotted part is the range of secondary reflection and effective light. From Figure 11, if you want to obtain pure secondary reflection and effective light, you must limit

The range of values and x values.

及x值的範圍做限制以濾除無效光線，如果我們限制了0<

<

DCRA

and x values to filter out invalid light. If we limit 0<

<

)<

,tan(-x+

)<

From (29), (32), tan( x +

)<

,tan(- x +

)<

We can get: x <0.063 π =11.34 ° ; 11.34 ° < x <0, combining the above: we can get the limit -11.34 ° < x <11.4 ° , x value range, 800 as shown in the dotted area in Figure 12, we can get pure secondary reflected light.

Optical Path Equation and DCRA resolution problem. From (3) and (18)(20)(25), the complete optical path equation can be obtained as follows: OPE ( x ) = AB + BC + CD

，

At this time 0 < x <

,

(x)這個函數，是一個平滑遞增變化的函數。在x接近

情況下，函數值會接近無窮大。其物理意義是，光線無法入射到DCRA的第一個反射鏡，是無效的光線。

( x ) is a smoothly increasing function.

In this case, the function value will approach infinity. Its physical meaning is that the light cannot enter the first reflector of DCRA and is invalid light.

<

及-11.34°<x<11.34°；可以求出

(x)邊界值如下；假設0<x<0.063π；相當於1.414<T ₂<1.803，

Considering the previous analysis, 0<

<

and -11.34 ° < x <11.34 ° ; we can find

The ( x ) boundary values are as follows; assuming 0 < x < 0.063 π ; this is equivalent to 1.414 < T ₂ < 1.803,

的值情況下的變化圖，其變化量不是很大。 As shown in Figure 13, RPE ( x ) is different in

The change graph under the value of , the change amount is not very large.

情況下；

exist

In this case;

情況下；

exist

In this case;

Combining equations (37) and (38) we can get

From (39), we can get,

△ OPE ( x )<0.354 W ---------------(40)

This value represents the pixel imaging error value generated by DCRA.

That is, the pixel image produced by DCRA is W + 0.354 W = 1.354 W.

Generally speaking, if the side length of a single pixel of our original display is p , then after passing through the DCRA panel, the side length of the final display is p '

A practical example of DCRA for lithography: Based on the above analysis, we propose a practical example of DCRA for lithography as follows: Assume that we use a 5.6-inch OLED panel used in mobile phones; the size is 151.3*70.1mm; the resolution is 1080P (2220X1080 pixels); the pixel size is 68*65um. The maximum pixel side length is 68um. If we want to obtain an image close to the original OLED panel level, 68um, according to formula (41)(1+0.354) W = 68 um

W =50 um

Regarding the application of DCRA in lithography, we all know that in lithography, a very high-resolution lens imaging device is a critical part; in order to eliminate aberrations and distortions, its structure becomes extremely complex and expensive. We believe that after the DCRA unit is miniaturized and ghosting is eliminated, it has the potential to be used as an imaging device in lithography. The DCRA's ability to perform floating projection can even be used in immersion lithography devices. As shown in Figure 14, a schematic diagram of the use of DCRA in an immersion exposure system 900, in which 910 is a UV light source, 920 is a mask, 930 is a DCRA element, 940 is a refractive index medium such as water or oil, 950 is a workpiece for exposure and development, and 960 is a mechanism for clamping the workpiece. Because DCRA has a sufficient working distance, it can perform exposure and development processes in liquid.

值的限制。 Masking is performed on DCRA to achieve

Value restrictions.

值做限制；如第15圖；DCRA之一單元130，做了遮罩處理的示意圖(左邊是立體視角示意圖，右邊是塗黑區域相對於坐標系之示意圖)，從途中可以看到下方光線進入的平面136進行了部分塗黑，上方出口的平面137不做處理)。這個處理方式來自於圖12的結果，對於

做限制。 This article discusses how to apply DCRA in practice.

As shown in Figure 15, a unit 130 of DCRA is masked (the left side is a three-dimensional view diagram, and the right side is a diagram of the blackened area relative to the coordinate system). It can be seen from the diagram that the plane 136 where the light enters from the bottom is partially blackened, and the plane 137 at the top of the exit is not processed). This processing method comes from the result of Figure 12.

Make restrictions.

<

的範圍，將

<

<1的部分(禁止線左方)做塗黑，以限制射入光線的範圍；如第16A圖，130L，考慮入射光與垂直軸的角度x=11.3入射底部平面136，從出口平面137射出，可以發現，左側的禁止線138在其中發揮了作用。在禁止線138右方0<

<

的入射光都成為有效光線，二次反 射後從出口平面137射出。如第16B圖，禁止線138也發揮了作用。在禁止線138左方

<

<1的一次無效入射光都被阻擋了。 That is, limit 0<

<

The range will

<

<1 (left side of the forbidden line) is painted black to limit the range of the incident light; as shown in Figure 16A, 130L, considering that the incident light is incident on the bottom plane 136 at an angle x = 11.3 with the vertical axis and exits from the exit plane 137, it can be found that the forbidden line 138 on the left plays a role.

<

All incident light becomes effective light and is emitted from the exit plane 137 after secondary reflection. As shown in FIG. 16B , the prohibition line 138 also plays a role.

<

All invalid incident light <1 is blocked.

<

的入射光都成為有效光線，二次反射後從出口平面137射出。如第17B圖，禁止線138也發揮了作用。在禁止線139右方

<

<1的一次無效入射光都被阻擋了。要注意的是禁止區域的塗黑只有在DCRA單元，面對入射光的平面136進行；出口平面137是不做處理的。 As shown in FIG. 17A, 130R, consider that the incident light is incident on the bottom plane 136 at an angle x = -11.3 with the vertical axis and exits from the exit plane 137. It can be found that the prohibition line 139 on the right side plays a role.

<

All incident light becomes effective light and is emitted from the exit plane 137 after secondary reflection. As shown in FIG. 17B , the forbidden line 138 also plays a role.

<

<1, all invalid incident light is blocked. It should be noted that the blackening of the forbidden area is only performed on the DCRA unit, on the plane 136 facing the incident light; the exit plane 137 is not processed.

For example, Figure 18 shows a schematic diagram of all DCRA units being blackened as prohibited areas; because the area is very small and fine, lithography technology is also required to achieve this in the process.

The DCRA light source is processed to limit the x value. From the previous analysis, in order to suppress invalid light from one reflection, the incident light must be limited. This part can generally be targeted at different light sources, such as LEDs, and corresponding lighting designs can be made, using collimators, reflectors or lens sets to reduce the angle distribution of light.

Regarding the application of DCRA in photocuring lamination manufacturing equipment, as mentioned above, the improved DCRA can be applied to photocuring lamination manufacturing equipment (3D printer); its design is similar to the immersion exposure system 900 in Figure 14; but the workpiece clamping mechanism 960 is changed to a lifting mechanism; it can perform precise vertical axis displacement and positioning, as shown in Figure 19, which is a three-dimensional view; and please refer to Figures 20A and 20B at the same time; its structure uses a UV light source 510, through an LCD panel 520 without a backlight, and enters a DCRA flat plate 530 that has been partially blackened. Then The final image 540 is in the liquid tank 550, 560 is the workpiece being printed, and 570 is the workpiece clamping and precision lifting device. Figure 20A is its side view, and Figure 20B is its front view. Its working method is exposure, light curing, and the elevator moves upward, and then the exposure, light curing, and shifting are repeated. Figure 21 is a schematic diagram of continuous printing from the initial stage 500A, to the intermediate stages 500B, 500C, to the final finished product stage 500D. Compared with the LCD type 3D printer mentioned earlier, this type does not have the process of tearing and separating the LCD release film, and can print directly, so the speed is much faster.

500: A 3D printer system using improved DCRA

520: LCD panel without light source

530: Improved DCRA flat panel with black finish

550: Light curing agent solvent tank

560: Finished workpiece of light curing

570: Workpiece clamping mechanism

Claims (4)

An improved double-angle reflector array flat plate and a photocuring type lamination manufacturing device are provided, which at least comprises: an LCD image display device; a collimated UV light source as a backlight source of the LCD image display device; a double-angle reflector array (DCRA) flat plate which is tilted at 45 degrees in front of the LCD image display device so that the image slice of the three-dimensional design object displayed by the LCD can be imaged in the photocuring tank; the double-angle reflector array (DCRA) flat plate is an optical flat plate composed of a plurality of double-angle reflector array (DCRA) units; one side of the unit facing the incident light is a rhombus flat surface, and the distance between the two diagonal points of the cross section of the DCRA flat plate is 1/4 of the distance between the two diagonal points of the cross section of the DCRA flat plate.

A triangular black area is formed on the left and right sides respectively; the black area is used to block the light that cannot form a normal image; a photocuring agent solvent tank; a workpiece clamping and moving device, which can clamp and move the exposed image slices; thereby, the image slices of the three-dimensional design object obtained from the photocuring agent solvent tank are gradually moved and stacked into a three-dimensional object. An improved dual-angle reflector array and a photocuring lamination manufacturing device as described in claim 1, wherein the pixel side length of the image slice at the imaging location is p ', and the width of the diamond unit of the dual-angle reflector array (DCRA) is W , and both should satisfy the relationship p '> 1.354W . An improved double-angle reflector array as described in claim 1 and applied to a photocurable laminate manufacturing device, wherein the plane of the LCD image display device is at a 45° angle to the plane of the DCRA plate; the plane of the DCRA plate is at a 45° angle to the plane of the image slice; and the plane of the LCD image display device is at a 90° angle to the plane of the image slice. A method for photocuring laminate manufacturing, comprising an improved double-angle reflector array plate as claimed in claim 1 and an apparatus for photocuring laminate manufacturing, the steps of which are as follows: Step 1, pre-slice the three-dimensional design object, and then send it to the ultraviolet imaging device one by one for exposure and displacement; Step 2, displace the workpiece to the light imaging area; Step 3, expose the above workpiece, photocuring and solidifying; Step 4, set up an elevator to clamp the workpiece and move it upward by a slice distance; Step 5, repeat the third step until all slices are exposed and cured.

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