# US 10,503,012 B2 · Fabrication method and fabrication apparatus for backlight source, display device, and a display system

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,503,012 B2
- Document ID: US10503012B2
- Status: Granted
- Kind: B2
- Application number: 15/770,632
- Filed: 2017-11-01
- Published: 2019-03-07
- Granted: 2019-12-10
- Earliest claimed: 2017-03-30
- Assignees: Boe Technology Group Co., Ltd.; Beijing Boe Display Technology Co., Ltd.
- Applicants: Boe Technology Group Co., Ltd.; Beijing Boe Display Technology Co., Ltd.
- Inventors: Shixin Geng; Jin Han; Tengfei Wang; Wei Zhang; Hao Zhou; Weihao Hu; Yu Zhang
- Web page: https://patentgrep.com/patent/US10503012B2

## CPC

- G02F 1/133609: {including means for improving the color mixing, e.g. white}
- G02F 1/133603: {with LEDs}
- G02F 1/133528: {Polarisers}
- H10W 90/00: Package configurations
- 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
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A method for fabricating a backlight source includes determining an n-step MacAdam ellipse in a uniform chromaticity diagram, where n is an integer smaller than or equal to 3; and fabricating the backlight source according to chromaticity coordinates within the n-step MacAdam ellipse to cause chromaticity coordinates of light emitted from different ones of light-emitting diodes of the backlight source to be within the n-step MacAdam ellipse.

## Claims

### Claim 1

A method for fabricating a backlight source, comprising:
determining an n-step MacAdam ellipse in a uniform chromaticity diagram, n being an integer smaller than or equal to 3; and
fabricating the backlight source according to chromaticity coordinates within the n-step MacAdam ellipse to cause chromaticity coordinates of light emitted from different light-emitting diodes of the backlight source to be within the n-step MacAdam ellipse,
wherein determining the n-step MacAdam ellipse includes:
determining a target color temperature of a display device including the backlight source;
determining an intersection of an isothermal line segment of the target color temperature and a Planckian locus in the uniform chromaticity diagram; and
determining the n-step MacAdam ellipse according to the isothermal line segment and the intersection, the intersection being within the n-step MacAdam ellipse, and two endpoints of the isothermal line segment being on the n-step MacAdam ellipse, and
wherein determining the n-step MacAdam ellipse according to the isothermal line segment and the intersection includes:
determining at least one initial ellipse according to the isothermal line segment and the intersection, each of the at least one initial ellipse having the intersection as a center point, and the two endpoints of the isothermal line segment being on each of the at least one initial ellipse;
matching the at least one initial ellipse with an m-step MacAdam ellipse in the uniform chromaticity diagram to determine, from the at least one initial ellipse, a largest initial ellipse containing the m-step MacAdam ellipse, wherein n≤m≤7;
determining a chromaticity-region quadrilateral according to the largest initial ellipse, the two endpoints of the isothermal line segment forming a first vertex and a second vertex of the chromaticity-region quadrilateral, respectively, a point on the largest initial ellipse corresponding to a minimum abscissa of the largest initial ellipse in the uniform chromaticity diagram forming a third vertex of the chromaticity-region quadrilateral, and a point on the largest initial ellipse corresponding to a maximum abscissa of the largest initial ellipse in the uniform chromaticity diagram forming a fourth vertex of the chromaticity-region quadrilateral; and
determining the n-step MacAdam ellipse in the chromaticity-region quadrilateral.

### Claim 2 (depends on 1)

A display device, comprising a backlight source and a display panel, the backlight source being fabricated by the method according to claim 1.

### Claim 3 (depends on 2)

A display system, comprising a plurality of display devices according to claim 2.

### Claim 4 (depends on 1)

The method according to claim 1, wherein:
the light-emitting diodes include at least two light-emitting diodes that emit white light of different wavelengths, and
the at least two light-emitting diodes have different red light components, different green light components, and different blue light components in the emitted white light.

### Claim 5 (depends on 4)

The method according to claim 4, wherein:
each two neighboring light-emitting diodes of the at least two light-emitting diodes emit white light of different wavelengths.

### Claim 6 (depends on 4)

The method according to claim 4, wherein:
among a plurality of chromaticity coordinates of white light emitted from the light-emitting diodes in the uniform chromaticity diagram, a number of chromaticity coordinates located on one side of the Planckian locus near to a lateral axis of the uniform chromaticity diagram is larger than a number of chromaticity coordinates located on another side of the Planckian locus farther away from the lateral axis of the uniform chromaticity diagram.

### Claim 7 (depends on 1)

The method according to claim 1, wherein:
n is equal to 3, and
the n-step MacAdam ellipse has a span less than or equal to approximately 0.01 in a lateral-axis direction of the uniform chromaticity diagram, and has a span less than or equal to approximately 0.00978 in a vertical-axis direction of the uniform chromaticity diagram.