Display device and optical module thereof

Abstract

A display device and an optical module thereof are provided. The optical module includes a light guide plate, a first light source and a second light source. The light guide plate has an inner light-emitting surface, an outer light-emitting surface opposite to the inner light-emitting surface, and a light-incident surface connecting the inner light-emitting surface and the outer light-emitting surface. The first light source is arranged on the light incident surface and located between the inner light emergent surface and the outer light emergent surface, and emitted light has a first color temperature. The second light source is arranged on the light incoming surface and located between the first light source and the inner light outgoing surface, light emitted by the second light source has a second color temperature, and the difference value between the first color temperature and the second color temperature is larger than 2000K. The optical module can emit light with proper color temperature so as to maintain or improve image quality, and reduce the arrangement distance of the light-emitting elements and the range of the light mixing area, thereby meeting the requirement of a narrow-frame product.

Description

Technical Field

[0001] The present invention relates to a display device, and more particularly to an optical module including light sources of different color temperatures, and a display device including the optical module. Background Art

[0002] Existing display devices usually include an optical module (front light module) and a display panel. The optical module emits light to illuminate the display surface of the display panel to display an image. The color temperature of the light has a certain degree of influence on the image, especially the color image. Therefore, when the optical module emits light with a suitable color temperature, it will help maintain or improve the image quality of the display device. However, the current method of adjusting the color temperature of the light from the optical module is to alternately arrange two light-emitting diodes with different color temperatures on the same light bar, and the arrangement spacing of light-emitting diodes with the same color temperature will increase on this dual-color temperature light bar, resulting in a larger mixed light area. Compared with the previous single-color temperature light bar, it is more difficult to apply to products with narrow borders. Summary of the invention

[0003] At least one embodiment of the present invention provides an optical module that can emit light with a suitable color temperature to maintain or improve image quality, and reduce the arrangement spacing of light-emitting elements and the range of the light mixing area, thereby meeting the product requirements of a narrow frame.

[0004] At least one embodiment of the present invention provides a display device including the above-mentioned optical module.

[0005] The optical module provided by at least one embodiment of the present invention comprises a light guide plate, a first light source and a second light source. The light guide plate has an inner light emitting surface, an outer light emitting surface and a light incident surface, the inner light emitting surface is opposite to the outer light emitting surface along a first direction, and the light incident surface connects the inner light emitting surface and the outer light emitting surface. The first light source is arranged on the light incident surface and is located between the inner light emitting surface and the outer light emitting surface along the first direction, and the light emitted has a first color temperature. The second light source is arranged on the light incident surface and is located between the first light source and the inner light emitting surface along the first direction, and the light emitted has a second color temperature, and the difference between the first color temperature and the second color temperature is greater than 2000K.

[0006] In at least one embodiment of the present invention, the light emitted by the first light source is one of cold light above 5300K and warm light below 3300K.

[0007] In at least one embodiment of the present invention, the light emitted by the second light source is the other of cold light above 5300K and warm light below 3300K.

[0008] In at least one embodiment of the present invention, the first light source and the second light source respectively include a circuit substrate and a plurality of light-emitting elements arranged on the circuit substrate, the circuit substrate of the first light source is attached to the outgoing light surface, and the circuit substrate of the second light source is attached to the inner light surface.

[0009] In at least one embodiment of the present invention, the light guide plate has a thickness in the first direction, each of the light emitting elements has a height in the first direction, and the height of each of the light emitting elements is no greater than half of the thickness of the light guide plate.

[0010] In at least one embodiment of the present invention, the height of each of the light emitting elements is no greater than 0.8 mm.

[0011] In at least one embodiment of the present invention, the light guide plate extends from the light incident surface along a second direction perpendicular to the first direction, and includes a light mixing area, the light mixing area has a width in the second direction, and each of the light-emitting elements is arranged on the circuit substrate at a spacing along a third direction perpendicular to the first direction and the second direction, and the ratio of the width of the light mixing area to the spacing of each arrangement of the light-emitting elements is less than 1.

[0012] The display device provided by at least one embodiment of the present invention comprises a display panel and an optical module. The display panel has a display surface, the optical module is arranged above the display surface of the display panel, and comprises a light guide plate, a first light source and a second light source. The light guide plate has an inner light emitting surface, an outer light emitting surface and a light incident surface, the inner light emitting surface faces the display surface and is opposite to the outer light emitting surface along a first direction, and the light incident surface connects the inner light emitting surface and the outer light emitting surface. The first light source is arranged on the light incident surface and is located between the inner light emitting surface and the outer light emitting surface along the first direction, and the light emitted has a first color temperature. The second light source is arranged on the light incident surface and is located between the first light source and the inner light emitting surface along the first direction, and the light emitted has a second color temperature, and the difference between the first color temperature and the second color temperature is greater than 2000K.

[0013] In at least one embodiment of the present invention, the first light source and the second light source respectively include a circuit substrate and a plurality of light-emitting elements arranged on the circuit substrate, wherein the circuit substrate of the first light source is attached to the outgoing light surface, and the circuit substrate of the second light source is attached to the inner light-emitting surface.

[0014] In at least one embodiment of the present invention, the display surface has a display area, the light guide plate includes a light mixing area located between the light incident surface and the display area, the light mixing area has a width in a second direction perpendicular to the first direction, and each of the light-emitting elements is arranged on the circuit substrate at a spacing along a third direction perpendicular to the first direction and the second direction, and the ratio of the width of the light mixing area to the spacing of each arrangement of the light-emitting elements is less than 1. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a cross-sectional schematic diagram of a reflective display device according to at least one embodiment of the present invention;

[0016] Figure 2 is a cross-sectional schematic diagram of an optical module according to at least one embodiment of the present invention;

[0017] Figure 3 is a schematic diagram of a light source according to at least one embodiment of the present invention;

[0018] Figure 4 is a schematic top view of a reflective display device according to at least one embodiment of the present invention.

[0019]

Explanation of symbols

[0020] 1: Reflective display device

[0021] 10: Optical module

[0022] 100: Light guide plate

[0023] 110: Light source

[0024] 111: The First Light Source

[0025] 111C, 112C: Circuit board

[0026] 111E, 112E: Light-emitting element

[0027] 112: Second light source

[0028] 20: Reflective display panel

[0029] 30: Connection layer

[0030] D1: First direction

[0031] D2: Second direction

[0032] D3: Third direction

[0033] DS: Display Surface

[0034] AA: Display area

[0035] H: Height

[0036] ML: Mixed light area

[0037] P: Spacing

[0038] S1: Inner light surface

[0039] S2: Outdoor smooth surface

[0040] S3: Light incident surface

[0041] T:Thickness

[0042] W: Width DETAILED DESCRIPTION

[0043] The following is a detailed discussion of the embodiments of the present invention. However, it is to be understood that the embodiments provide many applicable concepts that can be implemented in a variety of specific contexts. The embodiments discussed and disclosed are for illustration only and are not intended to limit the scope of the present invention.

[0044] In order to clearly present the technical features of the present invention, the dimensions of the components in the drawings will be enlarged in a non-proportional manner, and the number of some components will be reduced. Therefore, the description and explanation of the embodiments of the present invention are not limited to the number of components in the drawings and the dimensions and shapes presented by the components, but should cover the dimensions, shapes and deviations of the two caused by actual processes and / or tolerances. For example, the flat surface shown in the drawings may have rough and / or nonlinear features, and the sharp angles shown in the drawings may be rounded. Therefore, the elements presented in the drawings are mainly for illustration, and are not intended to accurately depict the actual shape of the elements, nor are they intended to limit the scope of protection claimed in the present invention.

[0045] The spatially relative terms used in the present invention, such as "below", "under", "above", "on", etc., are for the purpose of facilitating the description of the relative relationship between one element or feature and another element or feature, as shown in the figure. The true meaning of these spatially relative terms includes other orientations. For example, when the figure is flipped up and down 180 degrees, the relationship between one element and another element may change from "below" or "under" to "above" or "on". In addition, the spatially relative descriptions used in the present invention should also be interpreted in the same way.

[0046] It should be understood that, although the present invention may use the terms "first", "second", "third" and the like to describe various elements or features, these elements or features should not be limited by these terms. These terms are mainly used to distinguish one element from another element, or one feature from another feature. In addition, the term "or" used in the present invention may include any one or more combinations of the associated listed items depending on the actual situation.

[0047] In addition, the present invention may be implemented or applied through other different specific embodiments, and the details of the present invention may also be combined, modified and changed in various embodiments based on different viewpoints and applications without departing from the concept of the present invention.

[0048] Figure 11 is a cross-sectional schematic diagram of a reflective display device according to at least one embodiment of the present invention. The reflective display device 1 includes a reflective display panel 20 and an optical module 10. The reflective display panel 20 has a display surface DS, and the optical module 10 is disposed above the display surface DS of the reflective display panel 20, and includes a light guide plate 100 and a light source 110. The light guide plate 100 has an inner light emitting surface S1, an outer light emitting surface S2, and a light incident surface S3. The inner light emitting surface S1 faces the display surface DS and is opposite to the outer light emitting surface S2 along a first direction D1. The light incident surface S3 connects the inner light emitting surface S1 and the outer light emitting surface S2. The light source 110 is disposed on the light incident surface S3. The embodiment of the present invention takes a reflective display device as an example, but is not limited to this scope. In another embodiment of the present invention (not shown), the optical module 10 is disposed below the other surface (non-display surface) of the display device relative to the display surface DS. This structure is a non-reflective display device.

[0049] like Figure 1 As shown, the reflective display device 1 further includes a connection layer 30 disposed between the optical module 10 and the reflective display panel 20, for connecting the optical module 10 and the reflective display panel 20. In some embodiments, the material of the connection layer 30 can be optical clear adhesive (OCA), optical clear resin (OCR) and / or other suitable materials. In some embodiments, the reflective display panel 20 can be an electrophoretic display panel or an electrowetting display panel.

[0050] Figure 2 is a cross-sectional schematic diagram of an optical module according to at least one embodiment of the present invention. Figure 2 The optical module 10 includes a light guide plate 100 and a light source 110. The light source 110 includes a first light source 111 and a second light source 112. The first light source 111 is disposed on the light incident surface S3 and is located between the inner light emitting surface S1 and the outer light emitting surface S2 along the first direction D1, and the light emitted has a first color temperature. The second light source 112 is disposed on the light incident surface S3 and is located between the first light source 111 and the inner light emitting surface S1 along the first direction D1, and the light emitted has a second color temperature, and the difference between the first color temperature and the second color temperature is greater than 2000K.

[0051] The above arrangement of the first light source 111 and the second light source 112 that emit light of different color temperatures can emit light of appropriate color temperature to maintain or improve the image quality of the reflective display device 1. In addition, since the light-emitting elements of the first light source 111 are composed of a plurality of light-emitting elements 111E having substantially the same color temperature, and the light-emitting elements of the second light source 112 are composed of a plurality of light-emitting elements 112E having substantially the same color temperature, compared to the same light source having light-emitting elements of different color temperatures, the arrangement spacing of the light-emitting elements and the range of the light mixing area can be reduced, thereby meeting the product requirements of a narrow frame.

[0052] In some embodiments, the light emitted by the first light source 111 is one of cold light above 5300K and warm light below 3300K, and the light emitted by the second light source 112 is the other of cold light above 5300K and warm light below 3300K. For example, the light emitted by the first light source 111 may be cold light of 6500K, and the light emitted by the second light source 112 may be warm light of 2600K.

[0053] Please continue reading Figure 2 The first light source 111 and the second light source 112 respectively include circuit substrates 111C, 112C and a plurality of light emitting elements 111E, 112E disposed on the circuit substrates 111C, 112C. The circuit substrate 111C of the first light source 111 is attached to the external light emitting surface S2, and the circuit substrate 112C of the second light source 112 is attached to the internal light emitting surface S1. With the above design, the circuit substrate 112C attached to the internal light emitting surface S1 can replace the original black tape used to shield light leakage.

[0054] In some embodiments, the first light source 111 and the second light source 112 may be light bars, respectively. In some embodiments, the circuit substrates 111C and 112C may be flexible circuit boards. In some embodiments, the surfaces of the circuit substrates 111C and 112C attached to the outgoing light surface S2 and the inner light surface S1 may include a material with high reflectivity, such as titanium dioxide or white ink. In some embodiments, the surfaces of the circuit substrates 111C and 112C relative to the outgoing light surface S2 and the inner light surface S1 may include a material with high absorptivity, such as black ink. In another embodiment, the first light source 111 and the second light source 112 are made on the same circuit substrate (not shown) in an up-and-down arrangement, and the light sources are fixed to the sides of the light guide plate using fixing elements. The above-mentioned fixing elements are, for example, tape or a shell.

[0055] like Figure 2 As shown, the light guide plate 100 has a thickness T in the first direction D1, and each light emitting element 111E, 112E has a height H in the first direction D1, and the height H of the light emitting elements 111E, 112E is not greater than half of the thickness T of the light guide plate 100. In addition, the light guide plate 100 extends from the light incident surface S3 along a second direction D2 perpendicular to the first direction D1, and includes a light mixing area ML, and the light mixing area ML has a width W in the second direction D2, so that the light emitted by the first light source 111 and the second light source 112 is evenly mixed in the light mixing area ML before entering the display area.

[0056] In some embodiments, the light emitting elements 111E and 112E may be light emitting diodes (LEDs), such as sub-millimeter light emitting diodes (mini LEDs). Sub-millimeter LEDs can be divided into two types: one containing encapsulation glue and the other not containing encapsulation glue. The height of the sub-millimeter LED containing encapsulation glue may be less than 0.8 mm, while the height of the sub-millimeter LED without encapsulation glue may be less than 0.1 mm micrometers. In some embodiments, the height H of the light emitting elements 111E and 112E is not greater than 0.8 mm. In some embodiments, the light emitting elements 111E and 112E may be disposed on the circuit substrates 111C and 112C by wire bonding or flip chip method.

[0057] Since the first light source 111 and the second light source 112 of the optical module 10 of at least one embodiment of the present invention are arranged along the first direction D1, that is, along the direction of the thickness T of the light guide plate 100, and sub-millimeter light emitting diodes are used as the light emitting elements 111E and 112E, a light guide plate of general thickness or thinner thickness can be used, and there is no need to select a thicker light guide plate due to the arrangement method, so the lightness and thinness of the reflective display device can be maintained or improved.

[0058] Figure 3 is a schematic diagram of a light source according to at least one embodiment of the present invention. Figure 3 Taking the first light source 111 as an example, each light emitting element 111E is arranged on the circuit substrate 111C at a pitch P along a third direction D3 perpendicular to the first direction D1 and the second direction D2, and the ratio of the width W of the light mixing area ML to the pitch P of the light emitting elements 111E is less than 1. In addition, the pitch of the light emitting elements 112E of the second light source 112 also meets the above relationship.

[0059] Figure 4 is a top view schematic diagram of a reflective display device according to at least one embodiment of the present invention. Figure 4 The display surface DS has a display area AA, and the light guide plate 100 includes a light mixing area ML located between the light incident surface S3 and the display area AA. The light mixing area ML has a width W in a second direction D2 perpendicular to the first direction D1. Figure 3 and Figure 4 As shown, each light emitting element 111E, 112E is arranged on the circuit substrates 111C, 112C at a pitch P along a third direction D3 perpendicular to the first direction D1 and the second direction D2, and the ratio of the width W of the light mixing area ML to the pitch P of the light emitting elements is less than 1.

[0060] The following table is a comparative example and Figure 2 In detail, Figure 2The structure of the embodiment is that the first light source 111 includes a light emitting element 111E emitting light of the first color temperature arranged on the circuit substrate 111C along the third direction D3, and the second light source 112 includes a light emitting element 112E emitting light of the second color temperature arranged on the circuit substrate 112C along the third direction D3, and the first light source 111 and the second light source 112 are arranged on the light incident surface S3 of the light guide plate 100 along the first direction D1, that is, two single-color temperature light strips emitting light of different color temperatures are sequentially arranged on the light incident surface of the light guide plate along the thickness direction of the light guide plate. The structure of the comparative example is that a light source includes two light emitting elements emitting light of different color temperatures, which are alternately arranged on the circuit substrate, and this light source is arranged on the light incident surface of the light guide plate, that is, a dual-color temperature light strip emitting light of different color temperatures is arranged on the light incident surface of the light guide plate:

[0061]

[0062] As can be seen from the above table, the height of the light emitting element of the embodiment is half of the height of the light emitting element of the comparative example, so a light guide plate of the same thickness can be used. In addition, the arrangement spacing of the light emitting elements of the embodiment is smaller than that of the light emitting elements of the comparative example, and the width of its light mixing area is also smaller than that of the light mixing area of ​​the comparative example, so the frame width of the embodiment can be reduced by 6.5mm, that is, reduced by 65%, compared with the frame width of the comparative example.

[0063] Since the first light source 111 and the second light source 112 of the optical module 10 of at least one embodiment of the present invention respectively include a light emitting element 111E emitting light of the first color temperature and a light emitting element 112E emitting light of the second color temperature, relatively sparse and relatively dense dots (not shown) may be arranged on the light guide plate 100 at the light exits and intervals of the corresponding light emitting elements 111E and 112E, respectively, to help light mixing and reduce the width W of the light mixing area ML. However, in the comparative example, since one light source includes two light emitting elements emitting light of different color temperatures and arranged alternately, relatively sparse and relatively dense dots are arranged on the light guide plate at the light exits and intervals of one light emitting element, the dots on the light guide plate at the light exits of the other light emitting element will be relatively dense, and the dots on the light guide plate at the intervals will be relatively sparse, which will in turn cause the other light emitting element to generate a hot spot at its light exit. Therefore, in the case where the comparative example is not suitable for sparse and dense dots, a larger light mixing area width may be required.

[0064] In summary, the present invention can emit light with a suitable color temperature to maintain or improve the image quality of the reflective display device 1 by arranging the first light source 111 and the second light source 112 that emit light with different color temperatures of the optical module 10. In addition, since the light emitting elements of the first light source 111 are all of the same color temperature, and the light emitting elements of the second light source 112 are all of the same color temperature, compared with the same light source with light emitting elements of different color temperatures, the arrangement spacing of the light emitting elements and the range of the light mixing area can be reduced, thereby meeting the product requirements of a narrow frame.

[0065] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. A person having ordinary knowledge in the technical field may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the attached claims.

Claims

1. An optical module, characterized in that: include: A light guide plate having an inner light emitting surface, an outer light emitting surface and a light incident surface, wherein the inner light emitting surface is opposite to the outer light emitting surface along a first direction, and the light incident surface connects the inner light emitting surface and the outer light emitting surface; a first light source, disposed on the light incident surface and between the inner light emitting surface and the outer light emitting surface along the first direction, and emitting light having a first color temperature; and A second light source is disposed on the light incident surface and is located between the first light source and the inner light emitting surface along the first direction, and emits light having a second color temperature, wherein the difference between the first color temperature and the second color temperature is greater than 2000K.

2. The optical module according to claim 1, wherein: The light emitted by the first light source is one of cold light above 5300K and warm light below 3300K.

3. The optical module according to claim 2, wherein: The light emitted by the second light source is the other of cold light above 5300K and warm light below 3300K.

4. The optical module according to claim 1, wherein: The first light source and the second light source respectively include a circuit substrate and a plurality of light-emitting elements arranged on the circuit substrate, wherein the circuit substrate of the first light source is attached to the outgoing light surface, and the circuit substrate of the second light source is attached to the inner light surface.

5. The optical module according to claim 4, wherein: The light guide plate has a thickness in the first direction, and each of the plurality of light emitting elements has a height in the first direction, and the height is no greater than half of the thickness.

6. The optical module according to claim 5, wherein: The height is no greater than 0.8 mm.

7. The optical module according to claim 4, wherein: The light guide plate extends from the light incident surface along a second direction perpendicular to the first direction, and includes a light mixing area, the light mixing area has a width in the second direction, wherein each of the multiple light-emitting elements is arranged on the circuit substrate at a spacing along a third direction perpendicular to the first direction and the second direction, and the ratio of the width to the spacing is less than 1.

8. A display device, characterized in that: include: A display panel having a display surface; as well as an optical module, disposed above the display surface of the display panel, and comprising: a light guide plate having an inner light emitting surface, an outer light emitting surface and a light incident surface, wherein the inner light emitting surface faces the display surface and is opposite to the outer light emitting surface along a first direction, and the light incident surface connects the inner light emitting surface and the outer light emitting surface; a first light source, disposed on the light incident surface and between the inner light emitting surface and the outer light emitting surface along the first direction, and emitting light having a first color temperature; and A second light source is disposed on the light incident surface and is located between the first light source and the inner light emitting surface along the first direction, and emits light having a second color temperature, wherein the difference between the first color temperature and the second color temperature is greater than 2000K.

9. The display device according to claim 8, wherein: The first light source and the second light source respectively include a circuit substrate and a plurality of light-emitting elements arranged on the circuit substrate, wherein the circuit substrate of the first light source is attached to the outgoing light surface, and the circuit substrate of the second light source is attached to the inner light surface.

10. The display device according to claim 9, characterized in that The display surface has a display area, the light guide plate includes a light mixing area located between the light incident surface and the display area, the light mixing area has a width in a second direction perpendicular to the first direction, wherein each of the plurality of light-emitting elements is arranged on the circuit substrate at a spacing along a third direction perpendicular to the first direction and the second direction, and the ratio of the width to the spacing is less than 1.

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