Backlight module and display device
A display device includes a display panel, a light source on a substrate, and an adjacent light source. The adjacent light source is spaced apart from the light source by a predetermined distance. The light source emits light to irradiate an interface between the substrate and a member of the display panel via a lens. Light emitted from the light source irradiates a spot on the interface via the lens with luminance below a darkness level. The spot is aligned with the adjacent light source in a direction perpendicular to the substrate.
1 . A backlight module for a display device, comprising:
a substrate and four LED light sources disposed on the substrate, the four LED light sources forming a rectangle-shaped lighting unit,
wherein the four LED light sources are disposed at the lighting unit's four corners, respectively, the lighting unit has a length L along a first direction X and a width W along a second direction Y, and irradiates a rectangular area with the same length L and width W on an interface of the display device,
wherein a first LED light source of the four LED light sources comprises a first LED and a first lens disposed above the first LED, the first lens directing light rays emitted from the first LED onto
(1) a first corner of the rectangular area on the interface of the display device with a first luminance value E1,
(2) a second corner of the rectangular area with luminance of zero or substantially close to zero, wherein a distance between the first corner and the second corner is L along the first direction X,
(3) a first location (x, 0) with a luminance value E (x, 0) that is determined based on a linear change of luminance value from the first luminance value E1 at the first corner to zero luminance at the second corner, wherein the first location is on a first border line between the first corner and the second corner, and x is a distance between the first location (x, 0) and the first corner along the first direction X,
(4) a third corner of the rectangular area with luminance of zero or substantially close to zero, wherein a distance between the first corner and the third corner is W along the second direction Y,
(5) a second location (0, y) with a luminance value E (0, y) that is determined based on a linear change of luminance value from the first luminance value E1 at the first corner to zero luminance at the third corner, wherein the second location is on a second border line between the first corner and the third corner, and y is a distance between the second location (0, y) and the first corner along the second direction Y, and
(6) a location (x, y) of the rectangular area with a luminance value of E (x, y) that is a product of E (x, 0) and E (0, y).
2 . The backlight module of claim 1 , wherein the first LED is a mini light emitting diode (mini-LED).
3 . The backlight module of claim 1 , wherein the first LED has a dimension smaller than 300 micrometers along the first direction X or second direction Y.
4 . The backlight module of claim 1 , wherein luminance uniformity in the rectangular area on the interface of the display device is beyond a predetermined value when the four LED light sources at the lighting unit's four corners irradiate the rectangular area.
5 . The backlight module of claim 1 , wherein the display device has a liquid crystal display (LCD) panel.
6 . The backlight module of claim 1 , wherein the first lens and other lenses of the four LED light sources form a rectangle with the same length L and width W.
7 . The backlight module of claim 6 , wherein the first lens and the other lenses are made by molding.
8 . The backlight module of claim 7 further comprising a molded optical component including the first lens and the other lenses.
9 . The backlight module of claim 1 , wherein the length L and width W have different values and/or are smaller than 9 millimeters, respectively.
10 . The backlight module of claim 1 , wherein a distance between the interface and the substrate is smaller than 6 millimeters.
11 . A backlight module, comprising:
a substrate;
a first light source, disposed on the substrate;
a second light source, disposed on the substrate and adjacent to the first light source with a first distance between the first and second light sources in a first direction;
a third light source, disposed on the substrate and adjacent to the first light source with a second distance between the first and third light sources in a second direction perpendicular to the first direction, the first and second distances being different;
a first lens;
a second lens; and
a third lens,
wherein the first, second, and third lenses are respectively aligned to the first, second, and third light sources along a direction approximately perpendicular to the substrate, light emitted from the first light source passes through the first lens to irradiate a first region with luminance of a first value and irradiate a first middle region and a second middle region with luminance of a value that is half of the first value or substantially close to half of the first value, light emitted from the second light source passes through the second lens to irradiate a second region with luminance of a second value and irradiate the first middle region with luminance of a value that is half of the second value or substantially close to half of the second value, light emitted from the third light source passes through the third lens to irradiate a third region with luminance of a third value and irradiate the second middle region with luminance of a value that is half of the third value or substantially close to half of the third value, the first middle region is between the first region and the second region, and the second middle region is between the first region and the third region.
12 . The backlight module of claim 11 , wherein the first light source, the first lens, and the first region are aligned along the direction approximately perpendicular to the substrate.
13 . The backlight module of claim 11 , wherein the second light source, the second lens, and the second region are aligned along the direction approximately perpendicular to the substrate.
14 . The backlight module of claim 11 , wherein the first middle region is at a midpoint between the first region and second region.
15 . The backlight module of claim 11 , wherein light emitted from the first light source passes through the first lens to irradiate the second region with luminance below a predetermined darkness level.
16 . The backlight module of claim 11 , wherein light emitted from the second light source passes through the second lens to irradiate the first region with luminance below a predetermined darkness level.
17 . The backlight module of claim 11 , wherein the first and second light sources include a mini light emitting diode (mini-LED).
18 . The backlight module of claim 11 further comprising additional light sources and additional lenses, the first, second, and third light sources and the additional light sources forming an array of light sources of a predetermined grid pattern, and the first, second, and third lenses and the additional lenses forming an array of lenses of the predetermined grid pattern.
19 . The backlight module of claim 18 , wherein the array of lenses is made by a molding method.
20 . The backlight module of claim 11 , wherein a distance between the first region and the substrate is smaller than 6 millimeters.