Fiducial design
Methods and apparatuses related to fiducial designs for fiducial markers on glass substrates, or other transparent or translucent substrates, are disclosed. Example fiducial designs can facilitate visual recognition by enhancing edge detection in visual perception. In example fiducial designs, optical features on glass substrates can re-direct light so as to present a bright image region. Such optical features can include surface relief patterns formed in a coating on the surface of glass substrates. An exemplary method for manufacturing the fiducial markers can involve transfers of a fiducial design across a master mold or plate, a submaster mold or plate, and a target glass substrate. A fiducial marker can facilitate the use of the substrate in a variety of applications, including machine vision systems that facilitate automated performance of manufacturing processes on input working material.
1. A method of marking a target substrate with a target fiducial marker having a target fiducial design, the method comprising:
forming a master mold having a master surface relief pattern layer including the target fiducial design;
transferring a negative of the target fiducial design to a first mold by pressing together the master mold and the first mold;
separating the master mold and the first mold, the negative of the target fiducial design transferred to the first mold in a first surface relief pattern layer on the first mold;
depositing hardenable material onto the target substrate;
transferring the target fiducial design to the target substrate by pressing together the first mold and the target substrate; and
separating the first mold and the target substrate, the target fiducial design transferred to the target substrate in a target surface relief pattern layer in the hardenable material deposited onto the target substrate, the target surface relief pattern layer marking the target substrate with the target fiducial marker having the target fiducial design.
2. The method of claim 1 , further comprising:
coating a base substrate of the first mold with an adhesion promotion layer; and
depositing hardenable material on the adhesion promotion layer, before the master mold and the first mold are pressed together,
wherein the first surface relief pattern layer is formed from the hardenable material and adheres to the adhesion promotion layer coating the base substrate of the first mold after the master mold and the first mold are pressed together.
3. The method of claim 1 , further comprising:
depositing hardenable material onto a mold substrate, the hardenable material filling contours of the master surface relief pattern layer when the master mold and the first mold are pressed together; and
hardening the hardenable material, the hardened material forming the first surface relief pattern layer.
4. The method of claim 1 , further comprising:
applying a separation release coating to the first surface relief pattern layer,
wherein the separation release coating promotes the separation of the first mold and the target substrate.
5. The method of claim 1 , further comprising:
coating the target substrate with an adhesion promotion layer,
wherein the hardenable material is deposited onto the target substrate over the adhesion promotion layer coating the target substrate,
wherein the target surface relief pattern layer adheres to the adhesion promotion layer coating the target substrate.
6. The method of claim 1 ,
wherein the first mold comprises a press mold including the first surface relief pattern layer, and
wherein the press mold impresses the target surface relief pattern layer in the hardenable material deposited onto the target substrate.
7. The method of claim 1 , wherein the target substrate comprises a transparent material which is marked with the target fiducial design.
8. The method of claim 1 , wherein the target surface relief pattern layer comprises a surface relief profile area that presents a bright image region corresponding to an edge of the target fiducial marker.