Tool, device, apparatus and method
In one aspect of the invention for which protection is sought there is provided reader apparatus for reading an identification code carried by a surface feature device, the surface feature device having a plurality of respective surface feature portions each provided at respective lateral locations over a lateral surface at one of a plurality of predetermined distances from a lateral reference plane, the apparatus comprising a light source and a light detector, the apparatus being configured to direct light from the light source onto the respective surface feature portions of the surface feature device and to detect by means of the detector light scattered by the respective surface feature portions, the detector being configured to output a detector signal indicative of the intensity of light incident thereon, the apparatus being configured to generate a reader signal responsive to the distance of each of the respective surface feature portions of the surface feature device from the reference plane in dependence on the detector signal.
1. A marking device for forming an identification device in the form of a surface feature device in a surface, the identification device comprising indentations in a surface, the marking device comprising:
a plurality of fixed marking elements; and
an array of movable marking elements each configured to assume one of a plurality of predetermined positions by at least one actuator comprised by the device under the control of a controller, wherein in each predetermined position each respective movable marking element protrudes a respective different predetermined distance from a common reference plane, the device being configured to at least partially embed the movable marking elements in a surface of an article to form indentations of different respective depths therein, the respective depths corresponding to the predetermined distances from the common reference plane that the movable marking elements protrude.
2. The device according to claim 1 , wherein the movable marking elements are arranged to define a regular array of elements, wherein the array of elements is less than 1 cm square.
3. The device according to claim 1 , wherein the movable marking elements are arranged to define a regular array of elements, wherein the array of elements is less than 0.1 cm square.
4. The device according to claim 1 , wherein a plurality of the movable marking elements are spaced apart from one another by at least one of the fixed marking elements.
5. The device according to claim 1 , further configured to at least partially embed the fixed marking elements and the movable marking elements in a surface of an article to form indentations of different respective depths therein wherein the fixed marking elements are arranged to define an identification code.
6. The device according to claim 1 , further configured to cause local softening of a surface in contact therewith.
7. The device according to claim 1 , further configured to be provided in a wall of a mould tool defining a mould cavity, wherein indentations of the different respective depths may be formed in a moulded article formed by the mould tool.
8. A mould tool defining a mould cavity, the mould tool comprising a marking device according to claim 7 , wherein the marking device is arranged to form an identification device in a surface of an article formed in the mould cavity.
9. The mould tool according to claim 8 in combination with a controller, the controller being configured to receive a pressure signal indicative of a pressure within the mould cavity, the controller being configured to cause the plurality of actuators to apply force to the respective movable marking elements, the amount of force depending at least in part on the pressure signal.
10. The mould tool according to claim 9 , wherein the amount of force is arranged to increase with increasing pressure within the mould cavity.