Display device and method
There is provided a display device comprising a substrate; a spatial light modulator and a sealing element. The spatial light modulator is mounted on the substrate and comprises a light modulating region and an electrical connection region adjacent to the light modulating region. The sealing element comprises a primary portion comprising a first material and a secondary portion comprising a second material. The primary portion of the sealing element extends around at least a portion of a perimeter of the light modulating region and the secondary portion of the sealing element extends over the electrical connection region. The first material has a first coefficient of thermal expansion that is greater than a second coefficient of thermal expansion of the second material.
1 . A display device comprising:
a substrate;
a spatial light modulator mounted on the substrate and comprising a light modulating region and an electrical connection region adjacent to the light modulating region;
a sealing element comprising a primary portion comprising a first material and a secondary portion comprising a second material;
wherein the primary portion of the sealing element extends around at least a portion of a perimeter of the light modulating region and the secondary portion of the sealing element extends over the electrical connection region; and
wherein the first material has a first coefficient of thermal expansion that is greater than a second coefficient of thermal expansion of the second material.
2 . The display device of claim 1 , wherein the first coefficient of thermal expansion is at least double the second coefficient of thermal expansion.
3 . The display device of claim 1 , wherein the first coefficient of thermal expansion is one of (i) at least 20 parts per million per Kelvin, (ii) at least 50 parts per million, or (iii) at least 80 parts per million.
4 . The display device of claim 1 , wherein the second coefficient of thermal expansion is one of (I) less than 50 parts per million per Kelvin, (ii) less than 30 parts per million, or (iii) optionally less than 20 parts per million.
5 . The display device of claim 1 , wherein the first and second materials are selected from the group consisting of: amorphous polymers, and materials comprising at least one of a resin or silicone.
6 . The display device of claim 1 , wherein at least one of: (i) the first material has a first glass transition temperature that is less than a second glass transition temperature of the second material or (ii) the second material has a second glass transition temperature of more than 100 degrees Celsius.
7 . The display device of claim 1 , wherein the primary portion of the sealing element forms a continuous boundary and the spatial light modulator is fully contained within the continuous boundary.
8 . The display device of claim 7 , wherein:
the secondary portion of the sealing element is contained within the continuous boundary formed by the primary portion of the sealing element; and
the continuous boundary extends around the electrical connection region in a U-shape.
9 . The display device of claim 1 , wherein the light modulating region of the spatial light modulator has a quadrilateral shape and wherein the primary portion of the sealing element extends around first to third sides of the light modulating region.
10 . The display device of claim 9 , wherein:
the electrical connection region is adjacent to a fourth side of the light modulating region; and
the secondary portion of the sealing element extends along the fourth side of the light modulating region.
11 . The display device of claim 1 , wherein the perimeter of the light modulating region comprises a first portion and a second portion, wherein the primary portion of the sealing element extends around the first portion of the perimeter of the light modulating region, and wherein the secondary portion of the perimeter of the light modulating region is adjacent to the electrical connection region.
12 . The display device of claim 1 , wherein at least one of (i) the primary portion of the sealing element extends around at least 50% of the perimeter of the spatial light modulator or (ii) the primary portion of the sealing element extends around at least 60% of the perimeter of the spatial light modulator.
13 . The display device of claim 1 , wherein the electrical connection region comprises or is connected to one or more wire bond connections.
14 . The display device of claim 13 , wherein the one or more wire bond connections are covered by the secondary portion of the sealing element.
15 . The display device of claim 13 , further comprising a connector configured to connect the spatial light modulator to a controller, wherein the controller is configured to control the spatial light modulator, and wherein the one or more wire bond connections electrically connect the connector to the spatial light modulator.
16 . The display device of claim 15 , wherein the connector comprises at least one of (i) a flat flex connector, (ii) flexible printed cable, or (iii) a flexible printed circuit board.
17 . The display device of claim 1 , wherein the spatial light modulator is a liquid crystal on silicon spatial light modulator.
18 . A display device comprising:
a substrate;
a spatial light modulator mounted on the substrate and comprising a light modulating region and an electrical connection region adjacent to the light modulating region, wherein the electrical connection region comprises first contact portions;
a connector electrically connected to the spatial light modulator, wherein the connector comprises second contact portions electrically connected to respective first contact portions of the electrical connection region of the spatial light modulator;
a sealing element encapsulating the spatial light modulator on the substrate, the sealing element comprising a primary portion comprising a first material and a secondary portion comprising a second material;
wherein the primary portion of the sealing element extends around at least a portion of a perimeter of the light modulating region and the secondary portion of the sealing element extends over the electrical connection region comprising the first contact portions and the second contact portions of the connector; and
wherein the first material has a first coefficient of thermal expansion that is greater than a second coefficient of thermal expansion of the second material.
19 . The display device of claim 18 , wherein the first contact portions of the electrical connection region are connected to one or more respective wire bond connections such that the one or more respective wire bond connections are covered by the secondary portion of the sealing element.
20 . The display device of claim 19 , wherein the connector is arranged to connect the spatial light modulator to a controller, wherein the controller is configured to control the spatial light modulator, and wherein the one or more respective wire bond connections electrically connect the connector to the spatial light modulator.
21 . A head-up display for a vehicle comprising one of a first display device or a second display device, wherein:
the first display device comprises (i) a substrate, (ii) a spatial light modulator mounted on the substrate and comprising a light modulating region and an electrical connection region adjacent to the light modulating region, and (iii) a sealing element comprising a primary portion comprising a first material and a secondary portion comprising a second material, wherein the primary portion of the sealing element extends around at least a portion of a perimeter of the light modulating region and the secondary portion of the sealing element extends over the electrical connection region, and wherein the first material has a first coefficient of thermal expansion that is greater than a second coefficient of thermal expansion of the second material; and
the second display device comprises (i) a substrate, (iii) a spatial light modulator mounted on the substrate and comprising a light modulating region and an electrical connection region adjacent to the light modulating region, wherein the electrical connection region comprises first contact portions, (iii) a connector electrically connected to the spatial light modulator, wherein the connector comprises second contact portions electrically connected to respective first contact portions of the electrical connection region of the spatial light modulator, and (iv) a sealing element encapsulating the spatial light modulator on the substrate, the sealing element comprising a primary portion comprising a first material and a secondary portion comprising a second material, wherein the primary portion of the sealing element extends around at least a portion of a perimeter of the light modulating region and the secondary portion of the sealing element extends over the electrical connection region comprising the first contact portions and the second contact portions of the connector, and wherein the first material has a first coefficient of thermal expansion that is greater than a second coefficient of thermal expansion of the second material.
22 . A method of encapsulating a spatial light modulator for a substrate comprising a spatial light modulator mounted on the substrate, wherein the spatial light modulator comprises a light modulating region and an electrical connection region adjacent to the light modulating region, the method comprising:
forming a primary portion of a sealing element that extends around at least a portion of a perimeter of the light modulating region; and
forming a secondary portion of the sealing element that extends over the electrical connection region;
wherein the primary portion comprises a first material and the secondary portion comprises a second material, the first material having a first coefficient of thermal expansion that is greater than a second coefficient of thermal expansion of the second material.
23 . The method of claim 22 , wherein forming the secondary portion of the sealing element is performed after forming the primary portion of the sealing element.
24 . The method of claim 22 , wherein forming the primary portion of the sealing element comprises forming a continuous boundary that fully or partially contains the spatial light modulator and wherein forming the secondary portion of the sealing element comprises filling an area containing the electrical connection region and defined by the continuous boundary and the light modulating region with second material.
25 . A method of encapsulating a spatial light modulator on a substrate to form a display device, the method comprising:
providing a substrate comprising a spatial light modulator mounted on the substrate, the spatial light modulator comprising a light modulating region and an electrical connection region adjacent to the light modulating region, wherein the electrical connection region comprises first contact portions;
providing a connector electrically connected to the spatial light modulator, wherein the connector comprises second contact portions electrically connected to respective first contact portions of the electrical connection region of the spatial light modulator; and
encapsulating the spatial light modulator on the substrate by forming a sealing element, wherein encapsulating the spatial light modulator on the substrate by forming a sealing element comprises:
forming a primary portion of the sealing element extending around at least a portion of a perimeter of the light modulating region; and
forming a secondary portion of the sealing element extending over the electrical connection region comprising the first contact portions and the second contact portions of the connector;
wherein the primary portion comprises a first material and the secondary portion comprises a second material, the first material having a first coefficient of thermal expansion that is greater than a second coefficient of thermal expansion of the second material.