TWI634372B - Front light module have high contrast and high brightness and display - Google Patents

Abstract

The invention provides a front light module and a display with high contrast and brightness. The front light module includes a front light plate, a plurality of optical microstructures, an optical glue and a light source, and is combined with a reflective display panel to form a display. The optical microstructures are arranged on a light-emitting surface of the front light plate or a bottom surface of the opposite light-emitting surface, and each optical microstructure is a concave structure, and an angle between 155 and 175 degrees is provided between the side wall surface and the bottom surface. The optical glue is coated on the light emitting surface or the bottom surface and filled in the optical microstructure, and the refractive index of the optical glue is between 1.35 and 1.5. The light source is arranged corresponding to one of the light incident surfaces of the front light panel to provide side incident light, through which the light enters the front light panel, through the optical microstructure and optical glue to form a uniform light with high brightness and contrast, effectively improve the quality of the display picture .

Description

Optical module and display with high contrast and brightness

The invention relates to the field of front light modules, in particular to a front light module and a display having both high contrast and brightness.

Today's displays can be divided into two major categories, one is a transmissive display and the other is a reflective display. The transmissive display needs to use the backlight module arranged on the back of the display panel as a light source to achieve the display image effect. The display panel of the reflective display uses ambient light as a light source to reflect the ambient light irradiated to the display panel to achieve the display purpose. However, if the ambient light is insufficient, the display quality will be greatly affected, so most of the reflective displays will be equipped with a front light module placed on the front side of the display panel to use, in order to provide lighting in the case of insufficient ambient light The light is given to the display panel to maintain the display quality.

Both the aforementioned backlight module or front light module can use a light guide plate to achieve uniform light supply requirements. The light guide plate is an optical element that allows light provided by a light source such as an LED to be internally transmitted and appropriately emit light by destroying total reflection in a specific area to form a uniform surface light source. However, the light guide plate used in the backlight module or the front light module still has different considerations in development and design. Taking the former light module as an example, the light contrast and brightness provided by it are very important factors that affect the quality of the display. Therefore, in the design of the front light module, it is necessary to pay attention to these development points, such as the relative display of the front light module The main light output of the panel needs to have a certain intensity to allow the panel to reflect and then allow the user to view the display screen. On the other hand, since the front light module is The front of the display panel, so its design must also consider whether the structural presentation relative to the user's naked eye will cause visual defects.

In view of this, the present inventors devised a front light module and a display having both high contrast and brightness, so as to effectively improve the light output efficiency of the conventional front light module, thereby improving the display quality.

An object of the present invention is to provide a front optical module and a display with both high contrast and brightness, which have excellent light output performance, thereby improving the display quality of the display equipped with the configuration, and giving the user a better use experience .

In order to achieve the above object, the present invention discloses in one embodiment a front light module with high contrast and brightness for application in a reflective display, which includes: a front light plate with a light incident surface and a light exit surface, The light-emitting surface is vertically adjacent to the light-incident surface; a plurality of optical microstructures are arranged on the light-emitting surface or a bottom surface opposite to the light-emitting surface, and are respectively concave structures, and a side wall surface and the bottom surface of each optical microstructure are sandwiched by a The included angle is between 155 and 175 degrees; an optical adhesive is coated on the light emitting surface or the bottom surface, and the optical adhesive is filled with the optical microstructures, and the refractive index of the optical adhesive is between 1.35 and 1.5; And a light source, corresponding to the light incident surface, to provide side incident light; thereby, after the light from the light source enters the front light plate, the bottom surface is formed with high brightness through the optical microstructures and the optical glue It evenly emits light. In this way, through the included angle of the optical microstructure and the limitation of the refractive index of the optical glue, the light can be transmitted through the optical microstructure and the optical glue to form a uniform light with high brightness and contrast, and the display for matching applications has better display quality .

In another embodiment of the present invention, a high contrast and brightness are disclosed The display includes: a front light module, including: a front light plate, having a light incident surface and a light exit surface, the light exit surface and the light entrance surface are vertically adjacently arranged; a plurality of optical microstructures are arranged on the light exit surface Or a bottom surface opposite to the light-emitting surface, and each is a concave structure, an angle is formed between the side wall surface and the bottom surface of each optical microstructure, the angle is between 155 ~ 175 degrees; an optical glue is coated on the light-emitting surface Or the bottom surface, and the optical glue is filled with the optical microstructures, and the refractive index of the optical glue is between 1.35 ~ 1.5; and a light source, corresponding to the light incident surface to provide side light; and a reflection The display panel is set corresponding to the bottom surface; thereby, after the light from the light source enters the front light plate, it passes through the optical microstructures and the optical glue to form uniform light with high brightness and contrast on the bottom surface. The display of this embodiment can obtain uniform and high-brightness and contrast light through the front light module, thereby effectively improving the screen display performance.

Based on the foregoing two embodiments, in still another embodiment, the refractive index of the optical glue is preferably 1.5, so that the front light plate has a better light appearance.

Or in another embodiment, it is disclosed that the included angle of the optical microstructure is preferably 170 degrees, which also enables the light output of the front light plate to meet requirements.

Regarding the production of the front light plate, in one embodiment, it is disclosed that the front light plate is made by injection molding through a processing mold, and the processing mold is cut by rotating the cutter to form a copy of the front light plate during injection molding The optical microstructures with smooth surfaces are used to achieve rapid mass production of the front light plate and the optical microstructures thereon. However, in addition to tool cutting, the processing mold can also be processed by laser bombardment, and the optical microstructure with a rough surface is reprinted on the front light plate during injection molding, and the front optical plate with optical microstructure can also be quickly produced .

In addition, in addition to injection molding, in order to be more conducive to the production of thin front light board, in one implementation In the method, it is disclosed that the front light plate is made by roll-to-roll extrusion molding through a processing mold, and the processing mold is electroforming and reprinting a metal mold to form net-like bumps corresponding to the optical microstructures in On the processing mold, the purpose of rapid mass production of the light plate with the optical microstructure is achieved.

According to the foregoing, in still another embodiment, the metal mold is formed by the rotary cutting of the cutter, so that the mesh-like bumps have smooth surfaces, and then each of the optical microstructures is a concave structure with smooth surfaces, thereby making the printing The processing mold can be extruded on the front light plate to form an optical microstructure with a smooth surface.

Or in another embodiment, the metal mold is shaped by laser bombardment, so that the mesh-like bumps have a rough surface, and then each of the optical microstructures is a concave structure with a rough surface, thereby processing after reprinting The mold can be extruded on the front light plate to form an optical microstructure with a rough surface.

In order to improve the protection performance of the front light board, in one embodiment, the light emitting surface is coated with another optical glue, so that the front light board and a protective panel are bonded and assembled, thereby the front light board can be improved through the protective panel The ability of anti-wear or anti-scratch.

In addition, in one embodiment, it is disclosed that the maximum depth of each of the optical microstructures is between 1.4 and 1.6 μm, so as to prevent the user from peeking into the optical microstructures and affecting the display effect of the screen.

In summary, the present invention provides a high-contrast and brightness front optical module and display, which can be limited by the included angle of the optical microstructure on the front light plate and the refractive index of the matching optical gel to provide high contrast It emits light evenly with brightness, and effectively improves the overall display quality. In addition, the optical microstructure on the front light plate is a concave structure with a smooth surface or a rough surface according to the application method of the processing mold, and all can provide excellent light output performance. this In addition, in order to improve the service life and protection efficiency of the front light board, a protection panel can also be provided on it. In order to prevent the front light module from being turned on, the user can see the optical microstructures with the naked eye, thereby affecting the picture presentation. The depth of the optical microstructures of the front light module is also limited in order to provide more perfect and High-quality display.

1‧‧‧Front light module

10‧‧‧Front light board

101‧‧‧entrance

102‧‧‧Light

103‧‧‧Bottom

11‧‧‧Optical microstructure

111‧‧‧Oblique surface of optical microstructure

112‧‧‧Bottom surface of optical microstructure

12‧‧‧Optical glue

12a‧‧‧Optical glue

13‧‧‧Light source

2‧‧‧Monitor

20‧‧‧Reflective display panel

3‧‧‧Mould

30‧‧‧ Mesh bump

4‧‧‧Metal mold

5‧‧‧Protection panel

θ‧‧‧ included angle

A‧‧‧Cutter

B‧‧‧Laser

D‧‧‧Depth

Figure 1 is an exploded schematic view of an optical module and a reflective display panel before an embodiment of the present invention.

FIG. 2 is a schematic partial cross-sectional view of a light plate and optical glue before an embodiment of the present invention.

Figure 3 is a graph of the test results of the optical module before one embodiment of the present invention.

Fig. 4 is a schematic diagram of a metal mold cut by a tool according to an embodiment of the present invention.

Fig. 5 is a schematic diagram of laser processing of a metal mold according to an embodiment of the present invention.

Fig. 6 is a schematic diagram of extruding and forming of a light board before an embodiment of the present invention.

FIG. 7 is an exploded schematic view of an optical module, a reflective display panel, and a protective panel before an embodiment of the present invention.

As mentioned above, for the development of front light modules, most manufacturers tend to direct the main light toward the panel as one of the most important design elements, so that the display panel receives sufficient light intensity to reflect and display the picture, while the front light The light contrast of the module itself also has a significant impact on the display quality. In order to improve the light output efficiency of the front light module and increase the display quality of the mounted display, the inventor hereof proposes a front light module 1 with both high contrast and brightness, please refer to section 1, 2, 3, 4 Figures 5, 5 and 6 are exploded schematic diagrams of the front light module and the reflective display panel, partial cross-sectional schematic diagrams of the front light plate and optical glue, and front light module measurement according to an embodiment of the present invention. The test result diagram, the schematic diagram of the cutting process of the metal mold by the cutter, the schematic diagram of the laser processing of the metal mold and the schematic diagram of the extruding molding of the front light plate. The invention discloses a front light module 1 with high contrast and brightness, which is applied to a reflective display, including a front light plate 10, a plurality of optical microstructures 11, an optical glue 12 and a light source 13.

The front light board 10 has a light entrance surface 101 and a light exit surface 102, and the light exit surface 102 and the light entrance surface 101 are vertically adjacent to each other. The optical microstructure 11 is disposed on the light emitting surface 102 or a bottom surface 103 opposite to the light emitting surface 102, and is a concave structure. The side wall surface 111 and the bottom surface 112 of each optical microstructure 11 intersect at an angle θ, and the included angle θ is between 155 and 175 degrees. In this embodiment, the optical microstructures 11 are disposed on the bottom surface 103 as an example. The optical glue 12 is coated on the light emitting surface 102 or the bottom surface 103 and fills up the optical microstructures 11. The light source 13 can be a plurality of light-emitting diodes arranged on the circuit board in the form of a light bar, and is arranged corresponding to the light incident surface 101 to provide side-entry light, whereby the light from the light source 13 enters the front light board 1 and passes through the optical The microstructure 11 and the optical glue 12 form uniform light with high brightness on the bottom surface 103.

Through the limitation of the included angle of each optical microstructure 11 and the specific refractive index of the optical glue 12, it can effectively improve the overall light contrast and brightness of the front light module 1. The light output contrast referred to here is the brightness ratio of the front light module 1 when it is fully turned on, that is, when the light source 13 is turned on, and when the front light module 1 is fully turned off, that is, when the light source 13 is turned off, and through Maintaining the high light contrast of the front light module 1 can effectively improve the screen display effect of the mounted reflective display. Previously, the light output brightness of the optical module 1 was defined as the amount of positive light output from the bottom surface 103 to provide sufficient light output intensity so that the reflective display could reflect to form a display screen. In the past, the optical module 1 often caused light energy loss or other optical principle phenomena due to various factors, resulting in insufficient light brightness. The light brightness is actually an important factor that affects the quality of the display screen. Therefore, in the present embodiment, the former optical module 1 utilizes two conditions such as the included angle θ of the optical microstructure 11 and the refractive index of the optical adhesive 12 to effectively prevent the phenomenon of light brightness attenuation.

As shown in FIG. 3, the inventors also conducted relevant tests on the combination of each included angle θ and the refractive index of the optical adhesive 12, and it can be known that the included angle θ formed between the inclined surface 111 and the bottom surface 112 of each optical microstructure 11 Between 155 and 175 degrees, and the refractive index of the optical adhesive 12 is between 1.35 and 1.5, the front light module 1 can have better light contrast. When the angle θ between the inclined surface 111 and the bottom surface 112 of the optical microstructure 11 is too small, it will affect the maximum light output brightness of the front light module 1. Therefore, in order to obtain a better light appearance, the optical The angle θ of the microstructure 11 and the refractive index of the optical glue 12 are limited to the aforementioned range. In addition, in the preferred embodiment in which the angle of the optical microstructure 11 is 170 degrees or the refractive index of the optical adhesive 12 is 1.5, the best light contrast and brightness can be obtained. The method of making the optical microstructures 11 on the front light plate 10 is to directly cut through the cutter on the light emitting surface 102 or the bottom surface 103 of the front light plate 10 to form the optical microstructures 11 with a smooth surface, or through The laser bombardment process forms the optical microstructures 11 with rough surfaces.

In this embodiment, as shown in Figs. 4, 5 and 6, the front light plate 10 is manufactured by a processing die 2 in a roll-to-roll extrusion molding method, and the processing die 3 is an electroforming of a metal mold 4 After reprinting, a mesh-shaped bump 30 corresponding to the optical microstructure 11 is formed on the processing mold 3. Preferably, the metal mold 4 is formed by the rotary cutting of the cutter A, so that the reticulated mesh bumps 30 have a smooth surface, and then each optical microstructure 11 of the front light plate 10 is a concave structure with a smooth surface. More specifically, after the metal mold 4 is cut by the tool A, the electroforming or re-casting technology is used to produce the processing mold 3 with the mesh-like bumps 30, and then the processing mold 3 is pressed and printed on the front light plate 1 Smooth surface of the optical microstructure 11. Metal mold 4 except for In addition to cutting A, laser B can also be used to form the bomb. As shown in Figure 5, the mesh-like bumps 30 have a rough surface, and through the aforementioned electroforming reprinting or recasting technology, a processing mold 3 is produced. Then, the optical microstructure 11 with a rough surface is printed on the front light plate 1. However, the aforementioned electroforming is a conventional technology, so it will not be repeated here.

Although this embodiment is described by extruding the front light plate 1 as an example, the present invention is not limited to this. In addition to the extrusion process, the front light plate 10 can also be manufactured by injection molding through a processing mold, and the processing mold is rotated through a tool to cut and print the front light plate 10 to form the optical microstructures with a smooth surface during injection molding 11. More specifically, the processing mold 3 refers to a mold core that is further manufactured by the over-molding technology after the tool is rotated and cut, for example, the aforementioned electroforming overprinting or over-casting method can be used to make it have the corresponding optical microstructure 11 The structure can be directly formed into a smooth surface optical microstructure on the front light plate 10 during injection molding. Of course, in addition to cutting and turning molds to make the aforementioned processing molds, laser processing can also be used to make processing molds for injection molding, and during injection molding, the front light plate 10 is printed to form those with rough surfaces Optical microstructure 11.

In addition, it is particularly mentioned that since the front light module 1 is disposed on the front side of the reflective display, that is, a component directly viewed by the user, in order to prevent the user from viewing when the front light module 1 is not lit The optical microstructure 11 further affects the display effect of the picture. Preferably, the maximum depth D of each optical microstructure 11 is between 1.4 and 1.6 μm, so as to use a very shallow groove structure to prevent the user from having a defective visual perception.

Please refer to FIG. 7, which is an exploded schematic diagram of the optical module, the reflective display panel and the protective panel before an embodiment of the present invention. As shown in the figure, in order to have a better protection effect on the surface of the front light board 10, another optical glue 12a is coated on the light exit surface 102 to make the front light board 10 It is bonded and assembled with a protective panel 5, so that the anti-scratch and anti-wear performance of the front light board 10 can be improved. Even the material characteristics of the protective panel 5 can further provide optical adjustment performance. In this embodiment, the optical microstructure 11 is disposed on the bottom surface 103 as an example. If the optical microstructure 11 is disposed on the light emitting surface 102, the optical adhesive 12 having a refractive index between 1.35 and 1.5 can be coated again. Another layer of optical adhesive 12a is used to bond the protective panel 5, and this structure setting does not affect the light output efficiency of the front light module 1, and the optical adhesive 12a used to bond the protective panel 5 and the optical adhesive 12 filled in the optical microstructure 11 can Use the same colloid. In other words, whether the light emitting surface 102 is provided with a single layer of optical adhesive or a double layer of optical adhesive, it does not affect its uniform light output with high contrast and brightness.

Please refer to FIGS. 1 to 7 again. The present invention also discloses a display 2 with both high contrast and brightness, which includes the optical module 1 and a reflective display panel 20 as described above. The front light module 1 includes a front light board 10, an optical microstructure 11, an optical glue 12 and a light source 13. The front light plate 10 has a light entrance surface 101 and a light exit surface 102 that are perpendicularly adjacent to each other, the optical microstructure 11 is disposed on the light exit surface 102 or a bottom surface 103 opposite to the light exit surface 102, and is a recessed structure, the side of each optical microstructure 11 An angle θ is formed between the wall surface 111 and the bottom surface 112, and the angle θ is between 155 and 175 degrees. The optical adhesive 12 is coated on the light emitting surface 102 or the bottom surface 103 according to the arrangement position of the optical microstructure 11 and filled in the optical microstructure 11, and the refractive index of the optical adhesive 12 is between 1.35 ~ 1.5, and the light source 13 corresponds to the light incident surface 103 is set to provide side light. The reflective display panel 20 is provided corresponding to the bottom surface 103 to receive uniform high-brightness and contrast light emitted from the bottom surface 103 and achieve the purpose of displaying the picture. The rest of the technical features are detailed above, please refer to the previous content.

Similarly, as described in the previous embodiment, the refractive index of the optical adhesive 12 is preferably 1.5, and the included angle θ of the optical microstructure 11 is preferably 170 degrees. When the current optical module 1 is set under the foregoing conditions, the display 2 can be used Has the best display effect, and the optical microstructure 11 series can penetrate the cutter Cutting or laser processing. The manufacture of the front light plate 10 can be made by roll-to-roll extrusion molding using the processing mold 3 as shown in FIGS. 4-6, and the processing mold 3 is electroforming and reprinting the metal mold 4 to form mesh bumps 30 on the processing mold 3, and the metal mold 4 can be rotated and cut by the tool A and then after reprinting, forming the mesh-like bumps 30 with a smooth surface on the processing mold 3, or using laser B bombardment processing and After reprinting, the mesh-like bumps 30 with rough surfaces are formed on the processing mold 3, and then the front light plate 10 and the optical microstructure 11 thereon are fabricated. In addition to extrusion molding, the front light plate 10 can also be manufactured by injection molding, and the processing mold 3 used to make the front light plate 10 can also be cut by rotating the tool or processed by laser bombardment, and the mold is turned over for injection molding. The front light plate 10 and the optical microstructure 11 thereon. The rest of the technical features are detailed above, please refer to the previous content.

In addition, another optical adhesive 12a may be coated on the light exit surface 102 to allow the front light plate 10 and the protective panel 5 to be bonded and assembled to improve the protection against scratches and abrasion of the front light plate 10, as shown in FIG. 7 . Moreover, if the optical microstructure 11 is arranged on the light emitting surface 102, even if there are two layers of optical glue there, it will not affect the light emitting performance of the front light module 1. In addition, in order to prevent the user from seeing the optical microstructures 11 with naked eyes and affecting the display performance of the display 2, the maximum depth D of the optical microstructures 11 is preferably between 1.4 and 1.6 μm. The rest of the technical features are detailed above, please refer to the previous content. The rest of the technical features are detailed above, please refer to the previous content.

In summary, the present invention provides a high-contrast and brightness front optical module and a display, which can effectively improve the overall display quality. By the limitation of the angle of the optical microstructure on the front light board, and the matching refractive index of the optical glue Limited to provide uniform light output with high contrast and brightness. And the optical microstructure on the front light board can be directly cut or laser processed, or through the processing mold by extrusion molding or injection molding to form the front light board and the optical microjunction on it According to the construction method of the processing mold, the optical microstructure can be a concave structure with a smooth surface or a rough surface, and all can provide excellent light output performance. In addition, in order to improve the service life and protection performance of the front light board, the optical adhesive group can also be used to protect the panel, and to prevent the front light module from being lit, the user can see these optical microstructures with the naked eye. In turn, it affects the picture presentation. The front light module also limits the depth of the optical microstructure in order to provide a more complete and high-quality display picture.

However, the above are only preferred embodiments of the present invention and are not intended to limit the scope of the present invention; therefore, all changes and modifications made without departing from the spirit and scope of the present invention should be covered in Within the patent scope of the invention.

Claims (10)

A front light module with high contrast and brightness for application in a reflective display, which includes: a front light plate with a light incident surface and a light exit surface, the light exit surface is vertically adjacent to the light incident surface; The optical microstructures are arranged on the light-emitting surface or a bottom surface opposite to the light-emitting surface, and are respectively concave structures, and an angle is formed between the side wall surface and the bottom surface of each optical microstructure, and the angle is between 155 ~ 175 degrees; The optical glue is coated on the light emitting surface or the bottom surface, and the optical glue is filled with the optical microstructures, the refractive index of the optical glue is between 1.35 ~ 1.5; and a light source is provided corresponding to the light incident surface to Provide side entrance light; by this, after the light from the light source enters the front light plate, it passes through the optical microstructures and the optical glue to form uniform light with high brightness on the bottom surface. A display with both high contrast and brightness, including: a front light module, including: a front light board, having a light incident surface and a light exit surface, the light exit surface is perpendicularly adjacent to the light entrance surface; a plurality of optical micro The structure is arranged on the light emitting surface or a bottom surface opposite to the light emitting surface, and is respectively a concave structure, and an angle is formed between the side wall surface and the bottom surface of each optical microstructure, and the angle is between 155 ~ 175 degrees; an optical adhesive , Coated on the light emitting surface or the bottom surface, and the optical glue is filled with the optical microstructures, and the refractive index of the optical glue is between 1.35 ~ 1.5; and a light source, corresponding to the light incident surface to provide Side light; and a reflective display panel, corresponding to the bottom surface; thereby, after the light from the light source enters the front light plate, through the optical microstructures and the optical glue, the bottom surface is formed with high brightness and The contrast is evenly emitted. As described in item 1 of the patent application, the optical module with high contrast and brightness or the display with high contrast and brightness as described in item 2, wherein the refractive index of the optical glue is preferably 1.5. As described in Item 1 of the patent application, the optical module with high contrast and brightness or the display with high contrast and brightness as described in Item 2, wherein the included angle is preferably 170 degrees. As described in item 1 of the patent application, the high-contrast and brightness-before-light module or the high-contrast and brightness display as described in item 2, wherein the front light plate is manufactured by injection molding through a processing mold The processing mold is rotated and cut through the cutter to reprint the front light plate to form the optical microstructures with a smooth surface during injection molding. As described in item 1 of the patent application, the optical module with high contrast and brightness or the display with high contrast and brightness as described in item 2, wherein the front light plate is extruded on a roll-to-roll basis through a processing mold It is made by molding method, and the processing mold is electroforming and reprinting a metal mold to form net-shaped bumps corresponding to the optical microstructures on the processing mold. As described in item 6 of the patent application scope, the optical module with high contrast and brightness or the display with high contrast and brightness as described in item 6, wherein the metal mold is formed by rotary cutting of the cutter, so that these The mesh-like bumps have smooth surfaces, and each of the optical microstructures has a concave structure with smooth surfaces. As described in Item 6 of the patent application, the optical module with high contrast and brightness or the display with high contrast and brightness as described in Item 6, wherein the metal mold is shaped by laser bombardment The mesh-shaped bumps have rough surfaces, and each of the optical microstructures has a concave structure with rough surfaces. As described in item 1 of the patent application, the optical module with high contrast and brightness or the display with high contrast and brightness as described in item 2, wherein the light emitting surface is coated with another optical glue to The front light board is bonded and assembled with a protection panel. As described in item 1 of the patent scope, the optical module with high contrast and brightness or the display with high contrast and brightness as described in item 2, wherein the maximum depth of each optical microstructure is between 1.4 ~ 1.6μm.