A printing mold for LED bowls and cups

Abstract

The present invention discloses an LED bowl cup and a printing mold for improving screen brightness and contrast, and belongs to the field of LED display technology; the purpose is to improve the contrast and brightness index of the display screen through the structure of a small-sized LED bowl cup and the quality of printing ink; the bowl cup is formed by injection molding of a dark plastic material, and the bowl cup includes a conical cup body, a vertical cylindrical cup bottom and a cup mouth protruding from the cup body, and the cup mouth and the cup body form a stepped structure; a light-colored coating is arranged on the inner side of the cup body; the lower mold of the printing mold includes a plurality of printing convex heads arranged on a base, and a printing depth positioning step protruding from the printing convex head is arranged at the connection between the printing convex head and the base, and the structure of the printing convex head is adapted to the LED bowl cup, and the height of the printing depth positioning step is equal to the height of the cup mouth; the bowl cup and the mold with this structure can effectively control the coating thickness and coating coverage, improve the printing quality, and further improve the contrast and brightness index of the display screen.

Description

Technical Field

[0001] The invention belongs to the technical field of LED display, and relates to an LED cup and a printing mold for improving screen brightness and contrast, wherein the printing mold is applied to ink printing of small-sized LED cups. Background Art

[0002] In the field of LED display applications, in order to display clear and sharp picture quality, the brightness and contrast of the display screen are very important indicators. The calculation theory of contrast is based on the display screen in a completely dark dark field environment. The photometer probe is placed at a certain distance from the display screen, and the photometer probe is aimed at the center of the display screen. The brightness of the display screen when the screen is off is measured at IVa. The display screen is powered on and lit, and the brightness of the display screen when it is fully lit is measured at IVb. The contrast of the display screen is obtained by using IVb / Iva. The brightness of the dark field display screen is directly related to the brightness of the display screen surface. Since the LED surface accounts for about 50% of the display screen (the remaining 50% is a black mask or black glue), the blackness of the lamp surface directly affects the contrast of the display screen; and the display screen has another key indicator, which is brightness. The brightness of the display screen is mainly determined by the brightness of the LED. In addition to the LED chip, the brightness of the LED is also related to the reflectivity of the bowl of the packaging carrier. The reflectivity of white plastic reaches about 50%, and combined with the reflection of the silver-plated layer at the bottom of the cup, the reflectivity of the white plastic bowl cup reaches more than 80%; while the black plastic bowl cup has almost no reflection, and its reflection depends only on the silver-plated layer at the bottom of the bowl cup. Under the same conditions, the LED brightness of black plastic bowls and cups is 50%~60% lower than that of white plastic bowls and cups.

[0003] The brightness of the display screen is directly related to the size of the driving current of the display screen and the size of the LED chip used. The larger the current, the higher the brightness, and the larger the current, the higher the power consumption. Similarly, the larger the chip, the higher the brightness, but the cost is high. In order to obtain a higher contrast and a higher brightness at the same time, the display industry adopts the method of brushing black ink on the surface and surroundings of the bowl of the LED white plastic bracket to increase the contrast without sacrificing the brightness of the LED. This method has a good effect on the brushing of large-size LEDs of 2.5mm*2.5mm. For LED plastic bowls smaller than the above size, the brushing consistency is difficult to control, and it is easy to have problems such as ink flowing into the bowl or inconsistent brushing. Even if it can be completed, it will result in high cost and low yield. At the same time, the bowls made of white plastic injection molding will turn yellow due to high temperature baking of 150℃ or above during the LED packaging process and the downstream patch reflow process, resulting in different colors and flowery screens. Summary of the invention

[0004] The present invention overcomes the shortcomings of the prior art and provides an LED bowl cup and a printing mold for improving screen brightness and contrast, with the purpose of improving the contrast and brightness indicators of the display screen through the structure of a small-sized LED bowl cup and the quality of printing ink.

[0005] The present invention is achieved through the following technical solutions.

[0006] An LED bowl cup that improves screen brightness and contrast, the bowl cup is formed as one piece by injection molding of a dark plastic material, the bowl cup includes a conical cup body, a vertical cylindrical cup bottom and a cup mouth protruding from the cup body, the cup mouth and the cup body form a stepped structure; a light-colored coating is provided on the inner side of the cup body.

[0007] Furthermore, the bowl and cup are integrally formed by injection molding of black plastic material.

[0008] Furthermore, the side wall of the cup mouth is a conical slope.

[0009] Furthermore, the tapered slope of the side wall of the cup mouth has the same inclination angle as the cup body and is matched in size.

[0010] Furthermore, the height of the cup bottom is 0.02-0.1 mm.

[0011] Furthermore, the light-colored coating includes a white, light gray, or light yellow ink layer.

[0012] Furthermore, the dark plastic material is black, dark brown or dark blue.

[0013] The present invention also relates to a printing mold for printing light-colored ink on the wall of the LED bowl cup, comprising an upper mold and a lower mold, wherein the upper mold and the lower mold form a concave-convex mold structure, characterized in that the lower mold comprises a base and a plurality of printing convex heads evenly arranged on the base, a printing depth positioning step protruding from the printing convex head is provided at the connection between the printing convex head and the base, the structure of the printing convex head is adapted to the LED bowl cup, and the height of the printing depth positioning step is equal to the step height of the cup mouth.

[0014] Furthermore, an ink discharge hole is provided on the base.

[0015] Furthermore, the upper die is provided with a control head for squeezing the ink to control the ink thickness.

[0016] The bowl and cup are injection molded using dark plastic material. The bowl and cup structure is designed to be a special structure. The plastic height of about 0.02mm~0.1mm at the bottom of the bowl and cup is designed to be vertical (i.e., no draft angle). The vertical structure is conducive to avoiding contact with the inclined printing head and staining light or white ink to contaminate the bottom of the bracket cup. The plastic of the cup mouth is designed to be an enlarged step with the same slope as the bowl and cup, which is used to limit the depth of the printing head when it extends into the bowl and cup for printing, avoiding the printing head from contacting the bottom of the bowl and cup; the white ink printing on the wall of the bowl and cup is completed with a concave and convex mold structure, and the ink printing thickness is controlled by designing a suitable mold gap.

[0017] The beneficial effects of the present invention compared with the prior art are as follows.

[0018] The present invention uses a simple mold process to print white or other light-colored ink, resin and other colorants on the wall of the black plastic injection-molded bracket bowl and cup, thereby changing the color of the cup wall and improving the reflectivity of the bowl and cup wall, thereby improving the light brightness of the LED packaged with the bracket. Through this solution, the traditional method of brushing black ink on white plastic bowls and cups is changed to a method of using black or other dark plastic to make bowls and cups, and brushing ink on the walls of the bowls and cups to improve the brightness. The use of this solution can avoid the discoloration caused by external collision after the traditional white plastic is brushed with ink; when the same quality requirements are met, the cost of the bracket molded by black plastic injection molding is lower than that of the bracket molded by white plastic injection molding; by designing a vertical structure at the bottom of the bowl and cup structure, the bonding force between the potting glue and the bowl and cup can be increased; the bowl and cup mouth is designed to be stepped, which is conducive to controlling the consistency of the glue surface of the potting glue during LED packaging. The bowls and cups made of black plastic injection molding have good color consistency, avoiding the color spots caused by batch-by-batch ink inconsistency when traditional white plastic is inked on the five sides. In addition, white plastic will turn yellow when it undergoes a high-temperature reflow soldering process, but this problem does not occur when black plastic is used to make bowls and cups, which is beneficial to the brightness stability of the LED finished product. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the LED bowl and bottom bracket of the present invention.

[0020] Figure 2 This is a cross-sectional view of the LED bowl and bottom bracket of the present invention.

[0021] Figure 3 This is a cross-sectional view of the LED bowl cup described in the present invention.

[0022] Figure 4 It is a cross-sectional view of the upper mold and the lower mold of the printing mold described in the present invention.

[0023] Figure 5 This is a schematic diagram of spreading ink on the lower mold as described in the embodiment.

[0024] Figure 6 It is a schematic diagram of the mold closing described in the embodiment.

[0025] Figure 7 This is a schematic diagram of printing white ink in an LED bowl according to an embodiment.

[0026] Among them, 100 is the lower mold, 200 is the upper mold, 101 is the ink discharge hole, 102 is the printing depth positioning step, 103 is the printing convex head, 104 is the base, 105 is the mold stop position, 201 is the ink thickness control head, 301 is the ink, 400 is the bowl and cup, 401 is the outer pin of the bracket, 402 is the bottom of the cup, 403 is the cup mouth, 404 is the bracket direction identification notch, 405 is the ink layer, and 406 is the cup body. DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention is further described in detail in conjunction with the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The technical solutions of the present invention are described in detail below in conjunction with the embodiments and the accompanying drawings, but the scope of protection is not limited thereto.

[0028] like Figure 1 , Figure 2 and Figure 3 As shown, it is an LED bowl cup that can improve screen brightness and contrast. The bowl cup 400 is made of black plastic material by injection molding. The bowl cup 400 includes a conical cup body 406, a vertical cylindrical cup bottom 402, and a cup mouth 403 protruding from the cup body 406. According to design requirements, the height of the cup bottom 402 is 0.02-0.1mm. The side wall of the cup mouth 403 is a conical slope, and the conical slope of the side wall of the cup mouth 403 is equal to the inclination angle of the cup body 406. The cup mouth 403 and the cup body 406 form a stepped structure; the inner side of the cup body 406 is printed and coated with a white ink layer 405.

[0029] In addition, if Figure 4As shown, it is a printing mold for printing a white ink layer 405 on the inner side of the cup body 406 of the LED bowl cup. The printing mold is composed of an upper mold 200 and a lower mold 100. The upper mold 200 and the lower mold 100 form a concave-convex mold structure. The lower mold 100 includes a base 104 and a plurality of printing convex heads 103 evenly arranged on the base 104. The connection between the printing convex head 103 and the base 104 is provided with a printing depth positioning step 102 protruding from the side wall of the printing convex head 103. The structure of the printing convex head 103 is adapted to the LED bowl cup, and the height of the printing depth positioning step 102 is equal to the height of the cup mouth 403. An ink perfusion groove is formed between two adjacent printing convex heads 103, and an ink discharge hole 101 is provided on the base located at the center of the perfusion groove, which is used to discharge excess ink 301 from the ink discharge hole 101 when the mold is closed. In addition, the upper mold 200 is provided with an ink thickness control head 201, and a mold closing stopper 105 is provided at the bottom of the perfusion groove. By closing the upper and lower molds, the surface of the ink thickness control head 201 contacts the surface of the mold stopper 105 , and the mold gap is the ink thickness, and the excess ink can be discharged from the ink discharge hole 101 .

[0030] like Figure 5 —— Figure 7 As shown, the process of printing white ink on the inside of the LED bowl cup using a mold includes the following steps:

[0031] 1. Figure 5 As shown, firstly, white ink 301 is spread all over the surface of the lower mold 100;

[0032] 2. If Figure 6 As shown, mold closing: the ink is squeezed by the ink thickness control head 201 of the upper mold 200 to control the ink thickness, and the mold is closed until the ink thickness control head of the upper mold contacts the mold closing stop position 105. After the mold is closed, the excess ink 301 is discharged from the ink discharge hole 101;

[0033] 3. After closing the mold and controlling the ink thickness, open the mold;

[0034] 4. If Figure 7 As shown, the bowl cup 400 is placed upside down on the printing protrusion 103, and the printing depth positioning step 102 and the cup mouth 403 are abutted against each other to limit the position of the printing protrusion 103 deep into the bowl cup 400, and the ink on the surface of the printing protrusion 103 is transferred to the cup body 406 of the bowl cup 400.

[0035] The LED bowl cup of this structure uses a simple mold process to print white or other light-colored ink, resin and other colorants on the wall of the black plastic injection-molded bracket bowl cup, changing the color of the cup wall and improving the reflectivity of the bowl cup wall, thereby improving the brightness of the LED light packaged with the bracket. Through this solution, the traditional method of brushing black ink on white plastic bowl cups is changed to using black or other dark plastic to make bowl cups, and the method of brushing ink on the bowl cup wall to improve the brightness. The use of this solution can avoid the discoloration caused by external collision after the traditional white plastic is brushed with ink; when the same quality requirements are met, the cost of the bracket molded by black plastic injection molding is lower than that of the bracket molded by white plastic injection molding; by designing a vertical structure at the bottom of the bowl cup structure, the bonding force between the potting glue and the bowl cup can be increased; the bowl cup mouth is designed to be stepped, which is conducive to controlling the consistency of the glue surface of the potting glue during LED packaging. The bowls and cups made of black plastic injection molding have good color consistency, avoiding the color spots caused by batch-by-batch ink inconsistency when traditional white plastic is inked on the five sides. In addition, white plastic will turn yellow when it undergoes a high-temperature reflow soldering process, but this problem does not occur when black plastic is used to make bowls and cups, which is beneficial to the brightness stability of the LED finished product.

[0036] The above content is a further detailed description of the present invention in combination with a specific preferred embodiment. It cannot be determined that the specific embodiments of the present invention are limited to this. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the present invention, which should be regarded as belonging to the present invention and the scope of patent protection determined by the submitted claims.

Claims

1. A printing mold for LED bowl cups, comprising an upper mold and a lower mold, wherein the upper mold and the lower mold form a concave-convex mold structure, characterized in that: The lower mold comprises a base and a plurality of printing convex heads evenly arranged on the base, a printing depth positioning step protruding from the printing convex head is arranged at the connection between the printing convex head and the base, the structure of the printing convex head is adapted to the LED bowl cup, and the height of the printing depth positioning step is equal to the step height of the cup mouth; an ink perfusion groove is formed between two adjacent printing convex heads, and an ink discharge hole is arranged on the base located at the center of the perfusion groove, which is used to discharge excess ink from the ink discharge hole when the mold is closed; an ink thickness control head is arranged on the upper mold, and a mold closing stop position is arranged at the bottom of the perfusion groove; by closing the upper and lower molds, the surface of the ink thickness control head contacts the surface of the mold closing stop position, and the mold closing gap is the ink thickness, and the excess ink is discharged from the ink discharge hole; The LED bowl cup is formed by injection molding of a dark plastic material. The LED bowl cup includes a conical cup body, a vertical cylindrical cup bottom and a cup mouth protruding from the cup body. The cup mouth and the cup body form a stepped structure. The printing mold is used to print a light-colored coating on the inner side of the cup body of the LED bowl cup.

2. A printing mold for LED bowls and cups according to claim 1, characterized in that: The bowl and cup are integrally formed by injection molding of black plastic material.

3. The printing mold for LED bowl and cup according to claim 1, characterized in that: The side wall of the cup mouth is a tapered inclined surface.

4. The printing mold for LED bowls and cups according to claim 3, characterized in that: The conical slope of the side wall of the cup mouth has the same inclination angle as that of the cup body.

5. The printing mold for LED bowls and cups according to claim 1, characterized in that: The height of the cup bottom is 0.02-0.1 mm.

6. The printing mold for LED bowls and cups according to claim 1, characterized in that: The light-colored coating is a white, light gray, or light yellow ink layer.

7. The printing mold for LED bowls and cups according to claim 1, characterized in that: The dark plastic material is black, dark brown or dark blue.

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