# US 2021/0278877 A1 · Front light module and display device having the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0278877 A1 - Document ID: US20210278877A1 - Status: Published application - Kind: A1 - Application number: 17/114,517 - Filed: 2020-12-08 - Published: 2021-09-09 - Earliest claimed: 2020-03-06 - Assignees: E Ink Holdings Inc. - Applicants: E Ink Holdings Inc. - Inventors: Yun-Nan HSIEH; Chih-Cheng KO - Web page: https://patentgrep.com/patent/US20210278877A1 ## CPC - G06F 1/1609: {to support filters or lenses} - G06F 1/1637: {Details related to the display arrangement, including those related to the mounting of the display in the housing} - G02B 6/005: {provided by one optical element, or plurality thereof, placed on the light output side of the light guide} - G02B 6/0076: {Stacked arrangements of multiple light guides of the same or different cross-sectional area} - G02F 1/167: by electrophoresis - G02F 1/1677: Structural association of cells with optical devices, e.g. reflectors or illuminating devices - G06F 1/1601: {Constructional details related to the housing of computer displays, e.g. of CRT monitors, of flat displays (constructional details related to flat displays integrated in a portable computer, e.g. laptop, handheld computer G06F1/1637; constructional details related to television receivers H04N5/64)} - G06F 3/0412: {Digitisers structurally integrated in a display} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract A front light module includes a light guide plate, a light source, and a cover. The light guide plate has a light incident surface. The light source faces the light incident surface. The cover is located on the light guide plate. The cover includes a first light guide layer, a second light guide layer, a first printing layer, and a second printing layer. The first light guide layer is located between the second light guide layer and the light guide plate. The first printing layer is located on a surface of the first light guide layer facing the light guide plate. The second printing layer is located between the first light guide layer and the second light guide layer. ## Claims ### Claim 1 A front light module, comprising: a light guide plate having a light incident surface; a light source facing the light incident surface of the light guide plate; and a cover located on the light guide plate, wherein the cover comprises: a first light guide layer; a second light guide layer, wherein the first light guide layer is located between the second light guide layer and the light guide plate; at least one first printing layer located on a surface of the first light guide layer facing the light guide plate; and at least one second printing layer located between the first light guide layer and the second light guide layer. ### Claim 2 (depends on 1) The front light module of claim 1, wherein the first printing layer is in contact with the surface of the first light guide layer facing the light guide plate. ### Claim 3 (depends on 1) The front light module of claim 1, wherein a number of the first printing layer is plural, and one of the first printing layer closest to the first light guide layer is a light absorbing layer. ### Claim 4 (depends on 1) The front light module of claim 1, wherein the second printing layer is located on a surface of the first light guide layer facing the second light guide layer. ### Claim 5 (depends on 4) The front light module of claim 4, wherein the second light guide layer is a coating layer, and the coating layer is in contact with the first light guide layer and the second printing layer. ### Claim 6 (depends on 4) The front light module of claim 4, wherein the second light guide layer has a thickness in a range of 8 micrometers to 12 micrometers. ### Claim 7 (depends on 4) The front light module of claim 4, wherein a number of the second printing layer is plural, and one of the second printing layer closest to the first light guide layer is a light absorbing layer. ### Claim 8 (depends on 1) The front light module of claim 1, wherein the second printing layer is located on a surface of the second light guide layer facing the first light guide layer. ### Claim 9 (depends on 8) The front light module of claim 8, wherein the entire surface of the second light guide layer is planar, the second printing layer is in contact with the surface of the second light guide layer facing the first light guide layer, and the second printing layer is spaced apart from the first light guide layer. ### Claim 10 (depends on 8) The front light module of claim 8, wherein the second light guide layer has a thickness in a range of 70 micrometers to 80 micrometers. ### Claim 11 A display device, comprising: a front light module, comprising: a light guide plate having a light incident surface; a light source facing the light incident surface of the light guide plate; and a cover located on the light guide plate, wherein the cover comprises: a first light guide layer; a second light guide layer, wherein the first light guide layer is located between the second light guide layer and the light guide plate; at least one first printing layer located on a surface of the first light guide layer facing the light guide plate; and at least one second printing layer located between the first light guide layer and the second light guide layer; and a display module, wherein the light guide plate is located between the display module and the cover. ### Claim 12 (depends on 11) The display device of claim 11, wherein the first printing layer is in contact with the surface of the first light guide layer facing the light guide plate. ### Claim 13 (depends on 11) The display device of claim 11, wherein a number of the first printing layer is plural, and one of the first printing layer closest to the first light guide layer is a light absorbing layer. ### Claim 14 (depends on 11) The display device of claim 11, wherein the second printing layer is located on a surface of the first light guide layer facing the second light guide layer. ### Claim 15 (depends on 14) The display device of claim 14, wherein the second light guide layer is a coating layer, and the coating layer is in contact with the first light guide layer and the second printing layer. ### Claim 16 (depends on 14) The display device of claim 14, wherein the second light guide layer has a thickness in a range of 8 micrometers to 12 micrometers. ### Claim 17 (depends on 14) The display device of claim 14, wherein a number of the second printing layer is plural, and one of the second printing layer closest to the first light guide layer is a light absorbing layer. ### Claim 18 (depends on 11) The display device of claim 11, wherein the second printing layer is located on a surface of the second light guide layer facing the first light guide layer. ### Claim 19 (depends on 18) The display device of claim 18, wherein the entire surface of the second light guide layer is planar, the second printing layer is in contact with the surface of the second light guide layer facing the first light guide layer, and the second printing layer is spaced apart from the first light guide layer. ### Claim 20 (depends on 18) The display device of claim 18, wherein the second light guide layer has a thickness in a range of 70 micrometers to 80 micrometers. ### Claim 21 (depends on 11) The display device of claim 11, further comprising a touch layer, wherein the touch layer is located between the light guide plate and one of the cover and the display panel.