A reflector light collecting groove forming process based on variable distance regulation

Abstract

The application discloses a kind of based on variable distance regulation's reflector light groove forming process method, belong to backlight module reflector forming technical field.This method determines the forming after distance of lamp bead arrangement and three-dimensional light groove according to the optical requirement of lamp panel, determines the unfolding distance before forming of reflector according to the forming after distance and light groove height, and forms hole site on reflector;Reflectors are placed into matrix mold, and motor-driven connecting rod forming mechanism pushes and pushes reflector along two variable distance directions, so that hole site distance is contracted and light groove pre-forming part is formed;In the state of maintaining forming after distance, glue is applied and cured by ultraviolet curing lamp, to form reflector with three-dimensional light groove.This method can solve the problem that flat reflector is difficult to be controlled and formed into three-dimensional light groove according to lamp bead arrangement.

Description

Technical Field

[0001] This invention relates to the field of backlight module reflector molding technology, and in particular to a process method for molding reflector light-collecting grooves based on variable-pitch control. Background Technology

[0002] Reflectors are common optical components in direct-lit backlight modules, typically positioned on one side of the lamp panel and used in conjunction with light-emitting elements and diffusion structures. Chinese patent document CN102588882A discloses a reflector, a backlight module, and a television set. The reflector body has grooves that constrain the light emission angle of the LED lamps. This document indicates that the grooved structure on the reflector side can participate in the light emission adjustment of the light-emitting area, and the shape and position of the grooved structure affect the distribution of light within the corresponding light-emitting area.

[0003] As the number of LED chips in a Mini LED backlight structure increases, the light-emitting units on the LED board are typically arranged in an array at predetermined intervals. The reflective sheet needs to be designed with openings or localized structures according to the positions of the LED chips. Chinese patent document CN110061116B discloses a Mini LED backlight and its manufacturing method. This solution involves setting grooves at corresponding seams on the back panel and filling the grooves with cured white adhesive to improve the problem of localized dark lines in the Mini LED backlight. This type of solution demonstrates that in array-type backlight structures, optical compensation through localized grooves and cured reflective materials is already a common approach in the optical structure design of backlight modules.

[0004] However, existing technologies mainly focus on improving existing grooves, backplate grooves, or localized colloidal filling structures on the reflector body. For the process of fabricating three-dimensional light-collecting grooves using planar reflector materials, the planar reflector needs to have an unfolded spacing corresponding to the height of the light-collecting groove before molding, and after molding, it needs to match the spacing of the LEDs on the lamp board. Existing technologies have not yet provided a method for placing the perforated planar reflector into a matrix mold and pushing it along two variable-pitch directions to form multiple three-dimensional light-collecting grooves corresponding to the positions of the LEDs. Summary of the Invention

[0005] The purpose of this invention is to provide a process method for forming a light-collecting groove on a reflective sheet based on variable-pitch control. This method can solve the problem that it is difficult to form a three-dimensional light-collecting groove on a planar reflective sheet according to the controlled arrangement of the LED beads. It achieves the effect of shrinking the spacing of the reflective sheet from the pre-forming spacing to the post-forming spacing and shaping it into a three-dimensional groove shape.

[0006] To achieve the above objectives, the present invention provides the following solution: A method for forming a light-collecting groove for a reflective sheet based on variable-span control, comprising: The arrangement of LED beads is determined according to the optical requirements of the LED board, and the spacing of the three-dimensional light-collecting groove after molding is determined according to the arrangement of LED beads. The pre-forming unfolding spacing of the reflector is determined based on the pre-forming spacing and the height of the light-collecting groove. Holes corresponding to the lamp bead arrangement are formed on the reflector according to the pre-forming unfolding spacing to obtain the reflector to be formed. The reflective sheet to be formed is placed in the matrix mold of the variable-pitch forming equipment, so that the multiple holes correspond to the positioning structure of the matrix mold respectively; Start the pitch module of the pitch forming equipment, so that the motor drives the linkage forming mechanism to push the reflective sheet to be formed along the first pitch direction and the second pitch direction, so that the spacing between multiple holes shrinks from the pre-formed spacing to the post-formed spacing, and the sheet area between multiple holes arches to form a light-collecting groove pre-formed part with a three-dimensional groove profile. While maintaining the spacing after molding, the bonding position of the pre-formed light-collecting groove is glued and cured by a UV curing lamp to form a reflective sheet with a three-dimensional light-collecting groove. After the reflector with the three-dimensional light-collecting groove is demolded, it is attached to the lamp plate and pressed.

[0007] Preferably, the arrangement of LED beads is determined according to the optical requirements of the lamp board, and the spacing of the three-dimensional light-collecting groove after molding is determined according to the arrangement of LED beads, including: The number of LED beads and their arrangement area are determined based on the optical requirements of the LED panel. Determine the center position of multiple LED beads within the LED bead arrangement area; The distance between the center positions of two adjacent LED beads is determined as the post-forming spacing, so that the post-forming spacing is consistent with the LED bead spacing required after the three-dimensional light-collecting groove is formed.

[0008] Preferably, determining the pre-forming unfolding spacing of the reflective sheet based on the post-forming spacing and the height of the light-collecting groove includes: Based on the height of the finishing groove and the forming angle of the groove wall of the three-dimensional groove, determine the amount of unfolding compensation required for the sheet area between two adjacent holes during arching formation. Determine the pre-forming unfolding spacing based on the post-forming spacing and unfolding compensation amount; The pre-forming unfolding spacing corresponds to the hole spacing of the reflective sheet in a planar state.

[0009] Preferably, holes corresponding to the arrangement of LED beads are formed on the reflective sheet according to the pre-forming unfolding spacing to obtain the reflective sheet to be formed, including: The arrangement order of multiple holes is determined based on the arrangement of the LED beads; Determine the center distance between two adjacent holes according to the pre-forming spacing; The reflective sheet is perforated according to the arrangement of multiple holes and the center distance between two adjacent holes to obtain the reflective sheet to be formed.

[0010] Preferably, the reflective sheet to be formed is placed in a matrix mold of a variable-pitch forming device, such that multiple holes correspond to the positioning structures of the matrix mold, including: The reflective sheet to be formed is laid on the bearing surface of the matrix mold; Multiple holes are respectively fitted onto the corresponding positioning structures; The positioning structure restricts the initial position of multiple holes before variable pitch forming.

[0011] Preferably, the pitch module includes a motor, a transmission mechanism, and a connecting rod forming mechanism. The connecting rod forming mechanism includes a first pushing group arranged along a first pitch direction and a second pushing group arranged along a second pitch direction. The motor drives the first pushing group and the second pushing group to move through the transmission mechanism.

[0012] Preferably, the variable pitch module of the variable pitch forming device is activated, causing the motor-driven linkage forming mechanism to push the reflective sheet to be formed along the first variable pitch direction and the second variable pitch direction, including: The transmission mechanism is driven by a motor. The transmission mechanism drives the first pushing group to push the reflective sheet to be formed along the first pitch direction, so that the spacing between multiple holes in the first pitch direction is reduced. The transmission mechanism drives the second pushing group to push the reflective sheet to be formed along the second pitch direction, so that the spacing between multiple holes in the second pitch direction is reduced. The first pitch direction intersects with the second pitch direction.

[0013] Preferably, the pitch-changing module of the pitch-changing forming equipment is activated, causing the motor-driven linkage forming mechanism to push the reflective sheet to be formed along the first pitch-changing direction and the second pitch-changing direction, so that the spacing between multiple holes shrinks from the pre-forming spacing to the post-forming spacing, including: Determine the spacing shrinkage amount based on the pre-molding and post-molding spacing; The target pushing stroke of the linkage forming mechanism is determined based on the spacing shrinkage. The motor drives the linkage forming mechanism to move according to the target pushing stroke, so that the spacing between multiple holes is reduced to the spacing after forming.

[0014] Preferably, while the reflective sheet to be formed maintains the spacing after forming, adhesive is applied to the bonding position of the pre-formed portion of the light-collecting groove and cured by an ultraviolet curing lamp to form a reflective sheet with a three-dimensional light-collecting groove, including: The linkage forming mechanism is kept in a pushing state on the reflective sheet to be formed, and the pre-forming part of the light-collecting groove maintains a three-dimensional groove shape. Apply UV-curable adhesive to the bonding area; By irradiating the UV curing material with a UV curing lamp, the pre-formed part of the light-collecting groove is shaped into a three-dimensional light-collecting groove.

[0015] Preferably, after demolding the reflective sheet with the three-dimensional light-collecting groove, it is bonded to the lamp plate and held under pressure, including: The reflective sheet with a three-dimensional light-collecting groove is adsorbed by an adsorption mechanism, so that the reflective sheet with a three-dimensional light-collecting groove is detached from the matrix mold. A reflector with a three-dimensional light-collecting groove is attached to the lamp panel; Pressure is applied to the reflector sheet after it is attached to the lamp panel to fix the reflector sheet with three-dimensional light-receiving groove to the lamp panel.

[0016] The present invention discloses the following beneficial effects: (1) This invention determines the arrangement of LED beads according to the optical requirements of the lamp board, and determines the spacing of the three-dimensional light-collecting groove after molding based on the arrangement of LED beads. Then, it determines the pre-molding unfolding spacing of the reflector sheet based on the pre-molding spacing and the height of the light-collecting groove, so that the reflector sheet has reserved the sheet material allowance required to form the three-dimensional light-collecting groove in a planar state. As a result, the opening position of the planar reflector sheet is not directly formed according to the spacing of LED beads, but according to the pre-molding unfolding spacing, which can solve the problem that it is difficult to arch the planar reflector sheet to form the height of the light-collecting groove after directly opening the opening according to the spacing of LED beads.

[0017] (2) In this invention, the reflective sheet to be formed is placed in a matrix mold of a variable-pitch forming device, and multiple holes are respectively aligned with the positioning structure of the matrix mold. Then, the variable-pitch module drives the motor-driven linkage forming mechanism to push the reflective sheet to be formed along the first variable-pitch direction and the second variable-pitch direction, so that the spacing between the multiple holes shrinks from the pre-forming spacing to the post-forming spacing. The above process causes the sheet area between the holes to be controlled to arch in two directions, thereby forming a pre-formed part with a three-dimensional groove profile. That is, the difference between the pre-forming spacing and the post-forming spacing is converted into a three-dimensional forming allowance for the sheet area, and the planar reflective sheet can form a three-dimensional light-collecting groove without changing the material properties of the reflective sheet.

[0018] (3) In this invention, while the reflector to be formed maintains the spacing after forming, adhesive is applied to the bonding position of the pre-formed part of the light-collecting groove and cured by an ultraviolet curing lamp, so that the pre-formed part of the light-collecting groove is shaped into a three-dimensional light-collecting groove. Since the adhesive application and curing occur while the reflector to be formed is still constrained by the matrix mold and the linkage forming mechanism, the pre-formed part of the light-collecting groove does not detach from the forming position before curing, which can reduce the impact of the reflector's springback on the spacing after forming and the contour of the three-dimensional groove. Subsequent demolding, bonding and pressure holding are used to fix the reflector with the three-dimensional light-collecting groove to the lamp plate, ensuring that the three-dimensional light-collecting groove and the lamp bead arrangement maintain a corresponding relationship. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A flowchart of the method provided in an embodiment of the present invention; Figure 2 This is a schematic diagram showing the positional relationship between the light-receiving groove of the reflector and the lamp beads provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the reflective sheet to be formed provided in an embodiment of the present invention. Figure 4 This is a schematic diagram of a three-dimensional light-collecting groove structure provided in an embodiment of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Figure 1 The method flowchart provided in the embodiments of the present invention is as follows: Figure 1 As shown, this embodiment provides a method for forming a light-collecting groove for a reflective sheet based on variable-span control, including: Step 100: Determine the arrangement of LED beads according to the optical requirements of the lamp board, and determine the spacing of the three-dimensional light-collecting groove after molding according to the arrangement of LED beads; Step 200: Determine the pre-forming unfolding spacing of the reflective sheet based on the pre-forming spacing and the height of the light-collecting groove, and form holes on the reflective sheet corresponding to the arrangement of the lamp beads according to the pre-forming unfolding spacing to obtain the reflective sheet to be formed. Step 300: Place the reflective sheet to be formed into the matrix mold of the variable-pitch forming equipment, so that the multiple holes correspond to the positioning structure of the matrix mold respectively; Step 400: Start the pitch module of the pitch forming equipment, so that the motor drives the linkage forming mechanism to push the reflective sheet to be formed along the first pitch direction and the second pitch direction, so that the spacing between multiple holes shrinks from the pre-formed spacing to the post-formed spacing, and the sheet area between multiple holes arches to form a light-collecting groove pre-formed part with a three-dimensional groove contour. Step 500: While maintaining the spacing after molding, apply adhesive to the joint of the pre-formed part of the light-collecting groove and cure it with a UV curing lamp to form a reflective sheet with a three-dimensional light-collecting groove. Step 600: After demolding the reflective sheet with the three-dimensional light-collecting groove, attach it to the lamp plate and maintain pressure.

[0024] In this embodiment, the reflector is a sheet-like reflective material used in the backlight module. The reflector is planar before molding. The holes on the reflector are used to avoid or correspond to the LEDs on the LED panel. The three-dimensional light-collecting groove is a groove-shaped optical structure formed by pushing the sheet material area between the holes on the reflector. The post-molding spacing is the LED spacing that needs to be matched after the three-dimensional light-collecting groove is molded. The pre-molding unfolded spacing is the reserved spacing between adjacent holes when the reflector is in a planar state. The three-dimensional light-collecting groove has a light-collecting groove height; therefore, the pre-molding unfolded spacing is greater than the post-molding spacing.

[0025] In one alternative embodiment, the reflective sheet can be a high-reflectivity sheet material used in backlight modules, such as DJX225 reflective sheet material. This reflective sheet material has the characteristics of few surface defects, high flatness, high reflectivity, and good thermal stability, making it suitable for medium and large-sized LCD backlight modules. In this embodiment, the reflective sheet serves as the sheet substrate that transforms from a planar state into a three-dimensional light-collecting groove. The flatness of the reflective sheet is used to ensure the stability of the dimensional reference before the opening, the reflectivity of the reflective sheet is used to ensure that the three-dimensional light-collecting groove can still participate in the light output adjustment of the lamp board after molding, and the thermal stability of the reflective sheet is used to adapt to the subsequent UV curing and lamp board operating environment.

[0026] The total thickness of the reflective sheet can be 225 ± 10 micrometers, with a test value of 225 micrometers. The longitudinal and transverse tensile strengths of the reflective sheet can both be no less than 40 MPa, with test values ​​of 83 MPa and 74 MPa, respectively. The longitudinal and transverse elongation at break of the reflective sheet can both be no less than 20%, with test values ​​of 92% and 77%, respectively. These tensile strengths and elongation at break are used to provide the reflective sheet with a formable mechanical basis when subjected to two-dimensional variable-pitch extrusion in the X and Y axes, reducing the risk of breakage in the sheet area between the holes during the arching process.

[0027] The longitudinal thermal shrinkage rate of the reflective sheet under conditions of 85 degrees Celsius and 30 minutes can be no greater than 0.5%, and the transverse thermal shrinkage rate can be no greater than 0.2%, with test values ​​of 0.33% and 0.08%, respectively. The gloss level of the reflective sheet at 60 degrees can be 40 to 60 gloss units, with a test value of 50 gloss units. The reflectivity of the reflective sheet at a wavelength of 550 nanometers can be no less than 94.5%, with a test value of 94.8%. The above-mentioned thermal shrinkage rate, gloss level, and reflectivity are used to ensure that the reflective sheet maintains reflective performance that matches the optical requirements of the backlight module after completing variable-pitch molding, dispensing curing, and lamp panel bonding.

[0028] The reflector also meets reliability requirements under high temperature and humidity, thermal shock, high temperature storage, and low temperature storage conditions. The high temperature and humidity conditions are 60 degrees Celsius, 90% relative humidity, for 240 hours; the thermal shock conditions are maintained at -25 degrees Celsius for 1 hour to 65 degrees Celsius for 1 hour, cycled 50 times; the high temperature storage conditions are 85 degrees Celsius for 240 hours; and the low temperature storage conditions are -20 degrees Celsius for 240 hours. After testing under these conditions, the reflector maintains good performance. These reliability conditions are used to demonstrate that the reflector can adapt to the environmental reliability requirements of the backlight module after the three-dimensional light-receiving groove is formed, and do not constitute a limitation on the reflector material type or specific test conditions.

[0029] In step 100, the optical requirements for the lamp board may include the lamp board size, target brightness, optical uniformity requirements, and the number of LEDs. When determining the LED arrangement based on the lamp board's optical requirements, the number of LEDs to be arranged on the lamp board can be determined first, then the LED arrangement area can be determined based on the effective light-emitting area of ​​the lamp board, and the center positions of multiple LEDs can be determined within the LED arrangement area. The distance between the center positions of two adjacent LEDs is used as the post-forming spacing of the three-dimensional light-collecting groove. The post-forming spacing is used to define the target positional relationship of the three-dimensional light-collecting groove after its formation, so that the three-dimensional light-collecting groove can correspond to the LED arrangement on the lamp board.

[0030] The LED chips can be arranged in a matrix. A matrix arrangement includes multiple columns of LED chips arranged along the X-axis and multiple rows of LED chips arranged along the Y-axis. The X-axis can be used as the first pitch direction, and the Y-axis can be used as the second pitch direction. The post-forming spacing in the X-axis direction and the post-forming spacing in the Y-axis direction can be the same, or they can be set to different values ​​according to the LED panel design requirements. The first and second pitch directions can also be determined according to the installation direction of the matrix mold, and are not limited to a fixed direction in the horizontal coordinate system.

[0031] In step 200, when determining the pre-forming unfolded spacing of the reflector based on the post-forming spacing and the height of the light-collecting groove, geometric conversion can be performed according to the cross-sectional shape of the three-dimensional groove profile. The post-forming spacing corresponds to the planar spacing that matches the lamp bead arrangement after the three-dimensional light-collecting groove is formed. The light-collecting groove height corresponds to the height between the bottom section and the top transition section of the groove formed after the reflector is formed. The planar reflector needs to reserve sheet material allowance to form the three-dimensional groove profile; therefore, the holes are arranged according to the pre-forming unfolded spacing before forming.

[0032] Figure 2 This is a schematic diagram illustrating the positional relationship between the light-receiving groove of the reflector and the LED beads provided in an embodiment of the present invention. Figure 2 As shown, the reflector is formed into a continuously bent three-dimensional groove profile after being pushed by a variable pitch. The three-dimensional groove profile includes multiple sequentially connected groove bottom sections, inclined groove wall sections, and top transition sections; the LED is located at the corresponding position of the groove bottom section between two adjacent inclined groove wall sections. Figure 2 The position of the LED bead is used to indicate the correspondence between the LED bead on the LED board and the light-collecting groove after molding; the reflective sheet area between two adjacent LED bead positions is bent to form the lateral light-collecting boundary of the light-collecting groove. Figure 2 It is mainly used to show the cross-sectional outline of the reflector after it is formed and the positional relationship of the LED beads. It does not show the hole structure on the reflector, nor does it limit the specific shape of the LED beads, the angle of the wall of the light-collecting groove, or the size of the bottom section of the groove.

[0033] As an optional method for determining dimensions, the pre-forming unfolding spacing can be determined based on the post-forming spacing, the height of the light-collecting groove, and the unfolding path of the three-dimensional groove profile. The post-forming spacing corresponds to the target spacing between adjacent LED positions. The light-collecting groove height corresponds to the height difference between the bottom section and the top transition section in the three-dimensional groove profile. The unfolding path of the three-dimensional groove profile includes the sheet lengths corresponding to the bottom section, the inclined groove wall section, and the top transition section. The pre-forming unfolding spacing is determined according to the sheet length corresponding to the unfolding path, allowing for the sheet allowance required to form the three-dimensional groove profile while the reflector is in a planar state.

[0034] For example, the spacing after molding can be 16 mm, the height of the light-collecting groove can be 3 mm, and the pre-molding unfolded spacing can be 19.5 mm. In this case, the pre-molding unfolded spacing is greater than the post-molding spacing, and the difference in size between the two is used to provide the sheet material allowance required to form the bottom section, the inclined groove wall section, and the top transition section. The above values ​​are used to illustrate the dimensional correspondence when the reflective sheet is molded from a planar unfolded state into a three-dimensional groove shape, and do not limit the scope of protection of this invention.

[0035] When drilling holes in the reflector sheet, the arrangement order of multiple holes can be determined according to the LED bead layout, and the center distance between two adjacent holes can be determined according to the pre-forming unfolded spacing. Holes can be formed by punching, die-cutting, or laser cutting. The hole dimensions can be determined based on the LED bead shape, assembly gaps, and post-forming bonding requirements. The reflector sheet with completed hole processing serves as the reflector sheet to be formed. The hole spacing in the planar state of the reflector sheet to be formed is greater than the spacing after forming, providing sheet material allowance for subsequent two-dimensional variable-pitch pushing.

[0036] Figure 3 This is a schematic diagram of the reflective sheet structure to be formed according to an embodiment of the present invention. Figure 3 As shown, the reflector sheet has a sheet-like planar structure. The reflector sheet body is provided with multiple opening areas and multiple holes arranged in a matrix. The multiple opening areas are used to correspond to the sheet deformation area during subsequent variable pitch forming, and the multiple holes are used to correspond to the lamp bead arrangement and the positioning structure of the matrix mold. A sheet connecting part is retained between adjacent opening areas and adjacent holes. The sheet connecting part is used to form the groove wall or joint area of ​​the light receiving groove during the subsequent variable pitch pushing process. An outer edge notch can also be provided on the outer periphery of the reflector sheet for edge limiting or assembly avoidance. Figure 3 It is mainly used to represent the planar structural form of the reflective sheet before molding, as well as the arrangement relationship between the opening area, hole position, sheet connection part and outer edge contour, without limiting the specific shape of the opening area, hole position size or edge notch number.

[0037] In step 300, the variable-pitch forming equipment includes a matrix mold and a variable-pitch module. The matrix mold is used to support the reflective sheet to be formed. The positioning structure of the matrix mold is used to limit the initial position of the holes before variable-pitch forming. The positioning structure can be a positioning post, a positioning protrusion, or a positioning end that mates with the hole. When placing the reflective sheet to be formed, it can be laid on the bearing surface of the matrix mold, and the multiple holes are respectively fitted into the corresponding positioning structures. After the holes are aligned with the positioning structures, the reflective sheet to be formed maintains the pre-forming spread spacing before variable-pitch pushing.

[0038] A matrix mold can include multiple forming cavities or forming supports distributed in a matrix manner. The sheet areas between the corresponding holes in the multiple forming cavities or forming supports. After the reflector to be formed is positioned, the sheet areas between the holes are located at the corresponding forming positions in the matrix mold. When the linkage forming mechanism pushes the reflector to be formed, the sheet areas between the holes arch under the constraint of the matrix mold, forming a pre-formed section for the light-collecting groove.

[0039] The variable-pitch forming equipment can be equipped with a control panel. The control panel is used to input the pre-forming and post-forming pitches. During operation, the pre-forming unfolded size and the target post-forming size of the reflective sheet can be set on the control panel. For example, the pre-forming unfolded pitch can be set to 19.5 mm, and the post-forming pitch to 16 mm. The variable-pitch module controls the motor to operate according to the input dimensions, reducing the distance between adjacent pushing positions in the linkage forming mechanism from the distance corresponding to the pre-forming unfolded pitch to the distance corresponding to the post-forming pitch.

[0040] In step 400, the pitch-changing module may include a motor, a transmission mechanism, and a linkage forming mechanism. The linkage forming mechanism may include a first pushing group arranged along the X-axis and a second pushing group arranged along the Y-axis. The motor drives the first and second pushing groups to move via the transmission mechanism. The first pushing group pushes the reflector to be formed along the X-axis, and the second pushing group pushes the reflector to be formed along the Y-axis.

[0041] After the pitch-changing module is activated, the motor drives the transmission mechanism, which in turn moves the linkage forming mechanism. The first pushing group pushes the reflector to be formed along the X-axis, causing the spacing of multiple holes in the X-axis direction to shrink from the pre-forming unfolded spacing to the post-forming spacing. The second pushing group pushes the reflector to be formed along the Y-axis, causing the spacing of multiple holes in the Y-axis direction to shrink from the pre-forming unfolded spacing to the post-forming spacing. After pitch changing is completed in both the X-axis and Y-axis directions, the reflector to be formed shrinks from a large planar unfolded size to a post-forming size that matches the arrangement of the LED beads.

[0042] In one specific embodiment, the pre-formation spacing of the reflective sheet to be formed is 19.5 mm in both the X-axis and Y-axis directions. The post-formation spacing of the three-dimensional light-collecting groove is 16 mm in both the X-axis and Y-axis directions. After the variable-pitch module is activated, the spacing between adjacent holes in the X-axis direction shrinks by 3.5 mm, and the spacing between adjacent holes in the Y-axis direction shrinks by 3.5 mm. The sheet area between the holes is pushed in both directions and bent under the constraint of the matrix mold to form a pre-formed light-collecting groove with a three-dimensional groove profile.

[0043] Figure 4 This is a schematic diagram of a three-dimensional light-receiving groove structure provided in an embodiment of the present invention. Figure 4 As shown, the reflector sheet is pushed in two dimensions to form multiple light-collecting slots arranged in a matrix. The multiple light-collecting slots are connected end to end or adjacent at the edges. Each light-collecting slot has an outwardly protruding three-dimensional slot shape. The center of the light-collecting slot is provided with a hole corresponding to the position of the lamp bead. The light-collecting slot is surrounded by inclined slot walls. A sheet connection part is formed between adjacent light-collecting slots, and the sheet connection part corresponds to the joint position after molding. The multiple light-collecting slots together form an array-type three-dimensional light-collecting structure on the panel. Figure 4It is mainly used to represent the overall three-dimensional shape of the reflector after the variable-distance forming is completed, as well as the correspondence between the hole position, groove wall, sheet connection part and light-collecting groove array, without limiting the specific groove depth, groove wall angle or array number of light-collecting grooves.

[0044] In another embodiment, the first pushing group can push the reflective sheet to be formed along the X-axis direction first, and the second pushing group can then push the reflective sheet to be formed along the Y-axis direction. The first and second pushing groups can also move synchronously, so that the reflective sheet to be formed shrinks simultaneously in the X-axis and Y-axis directions. The pushing sequence can be determined according to the reflective sheet material, the hole arrangement, and the structure of the variable-pitch forming equipment.

[0045] For light panels with different row and column spacing, the pre-forming unfolding spacing in the X-axis direction and the pre-forming unfolding spacing in the Y-axis direction can be set separately. The post-forming spacing in the X-axis direction and the post-forming spacing in the Y-axis direction can also be set separately. The pitch-changing module controls the linkage forming mechanism to operate according to the spacing shrinkage in the X-axis and Y-axis directions, so that the reflector to be formed reaches the corresponding post-forming spacing in both directions.

[0046] During the two-dimensional variable-pitch extrusion process, the holes are guided by the positioning structure, and the sheet area between the holes is constrained by the matrix mold. The sheet allowance provided by the pre-forming spacing is transformed into the bottom section, inclined wall section, and top transition section during extrusion. The planar reflective sheet forms a pre-formed light-collecting groove within the matrix mold. This forming process occurs before the reflective sheet is demolded; the demolding and bonding stages do not involve secondary pitch changes to the three-dimensional light-collecting groove.

[0047] The preformed portion of the light-collecting groove can have a rectangular groove profile, a rounded rectangular groove profile, or a near-rectangular groove profile. For a lamp panel with multiple LEDs arranged in a matrix, a rectangular or near-rectangular groove profile can form a continuous light-collecting boundary between adjacent LEDs. For an independent light-collecting structure for a single LED, the preformed portion of the light-collecting groove can also adopt a groove profile adapted to the light-emitting area of ​​a single LED.

[0048] In step 500, after the reflective sheet to be formed is pushed to the post-forming spacing, the linkage forming mechanism maintains the pushing state of the reflective sheet to be formed, and the matrix mold maintains the constraint state on the hole positions and sheet area. At this time, the pre-forming part of the light-collecting groove has formed the target three-dimensional groove outline. The reflective sheet material has a springback tendency. If the reflective sheet to be formed is removed from the matrix mold before shaping, the pre-forming part of the light-collecting groove may spring back to a planar state, resulting in changes to the post-forming spacing, the position of the groove bottom section, or the shape of the inclined groove wall section.

[0049] The adhesive dispensing point can be set at the joint position of the pre-formed light-collecting groove. For multiple pre-formed light-collecting grooves arranged in a matrix, the joint position can be the cross-shaped meeting point of adjacent sheet areas, or the position where multiple sharp corners approach or contact after being pushed. During dispensing, the UV-curable adhesive is applied to the joint position, connecting adjacent sheet areas in the formed state. After the UV curing lamp irradiates the UV-curable adhesive, the UV-curable adhesive cures, and the pre-formed light-collecting groove is shaped into a three-dimensional light-collecting groove.

[0050] In one specific embodiment, multiple adjacent sheet areas form four closely spaced joint positions after being pushed together. A dispensing mechanism applies UV-curable adhesive to these joint positions, filling the gaps between adjacent corners or covering the contact areas of adjacent corners. After UV curing, the four corners are fixed in the molded state, and the three-dimensional groove shape is finalized before demolding.

[0051] In step 600, after UV curing, the reflective sheet with the three-dimensional light-gathering groove has a post-molding spacing that matches the arrangement of the LED chips in the lamp panel. During demolding, transfer, and bonding, the reflective sheet with the three-dimensional light-gathering groove is not subjected to secondary spacing adjustments. During demolding, an adsorption mechanism can be used to adsorb the reflective sheet with the three-dimensional light-gathering groove. The adsorption mechanism can include multiple suction cups. These suction cups can adsorb planar areas of the reflective sheet or positions that do not interfere with the three-dimensional light-gathering groove. The adsorption mechanism is used to maintain the flatness of the reflective sheet during demolding and transfer, reducing the impact of local warping on the bonding position.

[0052] After the reflector with a three-dimensional light-gathering groove detaches from the matrix mold, it can be transferred to the top of the lamp panel. Before bonding, the position of the LEDs on the lamp panel can be determined by visual or mechanical positioning, ensuring that the three-dimensional light-gathering groove corresponds to the LED arrangement. After positioning, the reflector with the three-dimensional light-gathering groove is bonded to the lamp panel and pressure is applied to fix it in place. When multiple reflectors with three-dimensional light-gathering grooves need to be bonded to a single lamp panel, each reflector can be positioned, bonded, and pressure-pressed separately, so that all reflectors together cover the LED arrangement area on the lamp panel.

[0053] The reflective sheet can be made of a high-reflectivity sheet material used in backlight modules. The reflective sheet can have various thicknesses, such as 0.188mm and 0.225mm, and possesses high reflectivity, flatness, and thermal stability. The reflectivity of the reflective sheet at a wavelength of 550 nm can be no less than 94.5%. Before molding, the reflective sheet material has a planar sheet structure, which can arch to form a three-dimensional groove profile during the variable-pitch molding process as the aperture spacing shrinks. The thickness, tensile strength, elongation at break, thermal shrinkage rate, and gloss of the reflective sheet material can be determined according to the optical requirements of the backlight module and the extrusion conditions of the variable-pitch molding equipment.

[0054] In this embodiment, the pre-molding spacing provides sheet material allowance for the planar reflective sheet to form a three-dimensional light-collecting groove. The post-molding spacing ensures that the three-dimensional light-collecting groove matches the arrangement of LED beads on the lamp board. A matrix mold restricts the forming position of the holes and sheet areas. The linkage forming mechanism performs two-dimensional variable-pitch pushing along the X-axis and Y-axis, transforming the reflective sheet from a planar state to a three-dimensional groove shape. Dispensing and UV curing are performed while the reflective sheet to be formed maintains the post-molding spacing, ensuring that the three-dimensional groove contour is fixed before demolding.

[0055] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0056] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method for forming a light-collecting groove for a reflective sheet based on variable-pitch control, characterized in that, include: The arrangement of LED beads is determined according to the optical requirements of the lamp board, and the spacing of the three-dimensional light-collecting groove after molding is determined according to the arrangement of the LED beads. The pre-forming unfolding spacing of the reflective sheet is determined according to the pre-forming spacing and the height of the light-collecting groove, and holes corresponding to the lamp bead arrangement are formed on the reflective sheet according to the pre-forming unfolding spacing to obtain the reflective sheet to be formed. The reflective sheet to be formed is placed in the matrix mold of the variable-pitch forming equipment, so that the multiple holes correspond to the positioning structure of the matrix mold respectively; Start the pitch module of the pitch forming equipment, so that the motor drives the linkage forming mechanism to push the reflective sheet to be formed along the first pitch direction and the second pitch direction, so that the spacing between the multiple holes shrinks from the pre-forming spacing to the post-forming spacing, and the sheet area between the multiple holes arches to form a light-collecting groove pre-forming part with a three-dimensional groove profile. While the reflective sheet to be formed maintains the spacing after forming, glue is applied to the joint position of the pre-formed part of the light-collecting groove and cured by ultraviolet curing lamp to form a reflective sheet with a three-dimensional light-collecting groove. After the reflective sheet with the three-dimensional light-collecting groove is demolded, it is attached to the lamp plate and pressed.

2. The method for forming a light-collecting groove for a reflective sheet based on variable-pitch control according to claim 1, characterized in that, The arrangement of LED beads is determined according to the optical requirements of the lamp board, and the spacing of the three-dimensional light-collecting groove after molding is determined according to the arrangement of the LED beads, including: The number of LED beads and the arrangement area of ​​the LED beads are determined according to the optical requirements of the lamp board. Determine the center positions of multiple LED beads within the LED bead arrangement area; The distance between the center positions of two adjacent LED beads is determined as the post-forming spacing, so that the post-forming spacing is consistent with the LED bead spacing required after the three-dimensional light-collecting groove is formed.

3. The method for forming a light-collecting groove for a reflective sheet based on variable-pitch control according to claim 1, characterized in that, The pre-forming unfolding spacing of the reflective sheet is determined based on the post-forming spacing and the height of the light-collecting groove, including: Based on the height of the light-collecting groove and the forming angle of the groove wall of the three-dimensional groove outline, determine the amount of unfolding compensation required for the sheet area between two adjacent holes during arching formation. The pre-forming unfolding spacing is determined based on the post-forming spacing and the unfolding compensation amount; The pre-forming unfolding spacing corresponds to the hole spacing of the reflective sheet in a planar state.

4. The method for forming a light-collecting groove for a reflective sheet based on variable-pitch control according to claim 1, characterized in that, According to the pre-forming unfolding spacing, holes corresponding to the lamp bead arrangement are formed on the reflective sheet to obtain the reflective sheet to be formed, including: The arrangement order of the multiple holes is determined based on the arrangement of the LED beads; The center distance between two adjacent holes is determined according to the pre-forming unfolding spacing. The reflective sheet is perforated according to the arrangement order of the multiple holes and the center distance between two adjacent holes to obtain the reflective sheet to be formed.

5. The method for forming a light-collecting groove for a reflective sheet based on variable-pitch control according to claim 1, characterized in that, The reflective sheet to be formed is placed in a matrix mold of a variable-pitch forming device, such that the plurality of holes correspond to the positioning structure of the matrix mold, including: The reflective sheet to be formed is laid on the bearing surface of the matrix mold; The plurality of holes are respectively fitted onto the corresponding positioning structures; The positioning structure restricts the initial position of the multiple holes before variable pitch forming.

6. The method for forming a light-collecting groove for a reflective sheet based on variable-pitch control according to claim 1, characterized in that, The pitch module includes the motor, the transmission mechanism, and the connecting rod forming mechanism. The connecting rod forming mechanism includes a first pushing group arranged along the first pitch direction and a second pushing group arranged along the second pitch direction. The motor drives the first pushing group and the second pushing group to move respectively through the transmission mechanism.

7. The method for forming a light-collecting groove for a reflective sheet based on variable-pitch control according to claim 6, characterized in that, Activating the pitch-changing module of the pitch-changing forming equipment causes the motor-driven linkage forming mechanism to push the reflective sheet to be formed along the first pitch-changing direction and the second pitch-changing direction, including: The transmission mechanism is driven by the motor. The transmission mechanism drives the first pushing group to push the reflective sheet to be formed along the first variable pitch direction, so that the spacing of the multiple holes in the first variable pitch direction is reduced. The transmission mechanism drives the second pushing group to push the reflective sheet to be formed along the second pitch direction, so that the spacing of the multiple holes in the second pitch direction is reduced. The first pitch direction intersects with the second pitch direction.

8. The method for forming a light-collecting groove for a reflective sheet based on variable-pitch control according to claim 1, characterized in that, Activating the pitch-changing module of the pitch-changing forming equipment causes the motor-driven linkage forming mechanism to push the reflective sheet to be formed along the first pitch-changing direction and the second pitch-changing direction, causing the spacing between the multiple holes to shrink from the pre-forming expanded spacing to the post-forming spacing, including: The spacing shrinkage amount is determined based on the pre-forming unfolded spacing and the post-forming spacing; The target pushing stroke of the connecting rod forming mechanism is determined based on the spacing shrinkage amount. The motor drives the connecting rod forming mechanism to move according to the target pushing stroke, so that the spacing between the multiple holes shrinks to the spacing after forming.

9. The method for forming a light-collecting groove for a reflective sheet based on variable-pitch control according to claim 1, characterized in that, While maintaining the pre-formed spacing of the reflective sheet to be formed, adhesive is applied to the bonding position of the pre-formed portion of the light-collecting groove and cured with a UV curing lamp to form a reflective sheet with a three-dimensional light-collecting groove, including: The linkage forming mechanism is kept in a pushing state on the reflective sheet to be formed, and the light-collecting groove preforming part maintains the three-dimensional groove outline; Apply UV-curable adhesive to the bonding location; The UV curing lamp irradiates the UV curing material, causing the pre-formed part of the light-collecting groove to be shaped into the three-dimensional light-collecting groove.

10. The method for forming a light-collecting groove for a reflective sheet based on variable-pitch control according to claim 1, characterized in that, After demolding the reflective sheet with the three-dimensional light-collecting groove, it is attached to the lamp plate and held under pressure, including: The reflective sheet with the three-dimensional light-collecting groove is adsorbed by an adsorption mechanism, so that the reflective sheet with the three-dimensional light-collecting groove is detached from the matrix mold. The reflector with the three-dimensional light-collecting groove is attached to the lamp plate; The reflector sheet attached to the lamp panel is pressurized to fix the reflector sheet with the three-dimensional light-receiving groove to the lamp panel.

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