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EP-4293418-B1 - LIGHT EMITTING DEVICE

EP4293418B1EP 4293418 B1EP4293418 B1EP 4293418B1EP-4293418-B1

Inventors

  • YUEH, JUI-JEN
  • LEE, KUAN-FENG

Dates

Publication Date
20260506
Application Date
20210330

Claims (10)

  1. Alight emitting device (100, 200, 300, 400, 500 or 600), comprising: a plurality of light emitting elements (120) for emitting lights; a light controller (130) disposed on the light emitting elements (120) for the lights passing through to form output lights, which is switchable in a first state (SU1) and a second state (SU2); and a first electrode (E1) and a second electrode (E2), wherein the light controller (130) is disposed between the first electrode (E1) and the second electrode (E2); wherein the light emitting device (100, 200, 300, 400, 500 or 600) has an illuminating surface (LS), the illuminating surface (LS) is an outermost surface which the output lights pass through, and a sum of an intensity of the output lights in the first state (SU1) is greater than a sum of an intensity of the output lights in the second state (SU2) in an angle with the illuminating surface (LS) ranged from 80° to 100°; wherein the light controller (130) comprises a plurality of switchable diffusers (132) disposed corresponding to the light emitting elements (120) and a plurality of light shielding elements (134) surrounding the plurality of switchable diffusers (132); wherein the light emitting device (100, 200, 300, 400, 500 or 600) further comprises a spacer (SP1) disposed between the plurality of light shielding elements (134) and the second electrode (E2), the spacer (SP1) is in contact with the plurality of light shielding elements (134) and the second electrode (E2) simultaneously, and the plurality of switchable diffusers (132) are connected to each other through a gap existing between the plurality of light shielding elements (134) and the second electrode (E2).
  2. The light emitting device (100, 200, 300, 400, 500 or 600) according to claim 1, characterized in that , the output lights in the second state (SU2) are uniformly scattered within an observable viewing angle.
  3. The light emitting device (100, 200, 300, 400, 500 or 600) according to any one of claims 1 to 2, characterized in that , the light emitting device (100, 200, 300, 400, 500 or 600) further comprises a plurality of peripheral traces (PT) respectively connected to the first electrode (E1) and the second electrode (E2).
  4. The light emitting device (100, 200, 300, 400, 500 or 600) according to any one of claims 1 to 3, characterized in that , the first electrode (E1) and the second electrode (E2) comprise a transparent conductive material.
  5. The light emitting device (100, 200, 300, 400, 500 or 600) according to claim 4, characterized in that , the first electrode (E1) and the second electrode (E2) comprise indium tin oxide.
  6. The light emitting device (100, 200, 300, 400, 500 or 600) according to any one of claims 1 to 5, characterized in that , at least one of the first electrode (E1) and the second electrode (E2) is patterned.
  7. The light emitting device (100, 200, 300, 400, 500 or 600) according to any one of claims 1 to 6, characterized in that , the light controller (130) comprises a wall (134 or 534) configured to filter the lights.
  8. The light emitting device (100, 200, 300, 400, 500 or 600) according to claim 7, characterized in that , an angle between a side wall (134a or 534a) of the wall (134 or 534) and the illuminating surface (LS) is greater than or equal to 80°.
  9. The light emitting device (100, 200, 300 or 400) according to any one of claims 1 to 6, characterized in that , the lights pass through the plurality of switchable diffusers (132) to form the output lights, and the plurality of switchable diffusers (132) are switched to make the light controller (130) switchable in the first state (SU1) and the second state (SU2).
  10. The light emitting device (100, 200, 300, 400, 500 or 600) according to any one of claims 1 to 9, characterized in that , the sum of the intensity of the output lights in the second state (SU2) in the angle ranged from 80° to 100° is less than 80% of a total intensity of the output lights in the second state (SU2).

Description

Field of the Disclosure The present disclosure relates to a light emitting device which can control or change direction of light. Background of the Disclosure As the evolution and development of electronic devices, the electronic devices have become an indispensable item. The electronic devices such as display devices or light emitting devices can provide more convenient information transmission or image display. However, as the users attach importance to privacy when viewing these devices, or as the safety requirements to prevent specific persons from viewing these devices are increased (e.g., prevent the driver from watching the display device or the light emitting device of the car while driving, or prevent the lights emitted by the display device or the light emitting device of the car from being projected on the windshield to interfere with the driver), these devices need to have the function of controlling the direction of light. US 10578895B2 discloses a backlight unit for a liquid crystal display panel. The backlight unit comprises a switchable louver made of a polymer dispersed liquid crystal (PDLC) layer with a grid of channels filled with electrophoretic (EC) medium and surrounding portions of the PDLC. The PDLC portions are switchable between a scattering and a transparent state, while the EC walls surrounding them are switchable between absorbtive and transparent state. CN110568653A discloses a similar backlight unit to the one disclosed in US 10578895B2 wherein, however, the walls surrounding the PDLC portions are absorptive without being switchable. Summary of the Disclosure This in mind, the present disclosure aims at providing a light emitting device having a light controller for controlling or adjusting the light direction emitted from the light emitting element, so as to enhance the privacy of viewing and/or prevent specific persons from viewing. This is achieved by a light emitting device according to the independent claims. The dependent claims pertain to corresponding further developments and improvements. As will be seen more clearly from the detailed description following below, the claimed light emitting device includes a plurality of light emitting elements and a light controller. The light emitting elements are emitting lights. The light controller is disposed on the light emitting elements for the lights passing through, which is switchable in a first state and a second state. The light controller collimates the lights in the first state and diffuses the lights in the second state. As will be seen more clearly from the detailed description following below, the claimed light emitting device includes a plurality of light emitting elements and a light controller. The light emitting elements are emitting lights. The light controller is disposed on the light emitting elements. The light controller includes a plurality of cells for the light from the light emitting elements passing through and a plurality of walls surrounding the cells. The walls are switchable in states of a transmissive state and a non-transmissive state. Brief Description of the Drawings In the following, the disclosure is further illustrated by way of example, taking reference to the accompanying drawings. Thereof FIG. 1 is a schematic diagram showing a top view of a light emitting device according to a first embodiment of the present disclosure, which is not according to the claimed invention,FIG. 2 is a schematic diagram showing a cross-sectional view of the light emitting device taken along a cross-sectional line A-A' in FIG. 1,FIG. 3 is a schematic diagram showing a cross-sectional view of a structure and lights of the light emitting device in a first state and a structure and lights of the light emitting device in a second state according to the first embodiment of the present disclosure, which is not according to the claimed invention,FIG. 4 is a schematic diagram showing a light controller in a first state and a light controller in a second state according to the first embodiment of the present disclosure, which is not according to the claimed invention,FIG. 5 is a schematic diagram showing a top view of a light emitting device according to a second embodiment of the present disclosure, which is according to the claimed invention,FIG. 6 is a schematic diagram showing a cross-sectional view of the light emitting device taken along a cross-sectional line B-B' in FIG. 5,FIG. 7 is a schematic diagram showing a cross-sectional view of the light emitting device taken along a cross-sectional line C-C' in FIG. 5,FIG. 8 is a schematic diagram showing a cross-sectional view of a light emitting device according to a third embodiment of the present disclosure, which is not according to the claimed invention,FIG. 9 is a schematic diagram showing a cross-sectional view of a structure and lights of a light emitting device in a first state and a structure and lights of a light emitting device in a second state according to