Print cartridge registration systems

1 . An apparatus, comprising:

a movable stage to hold a well plate;

a print cartridge holder to hold a print cartridge comprising a print die over the movable stage, wherein the print die is to eject fluid;

a camera located above the movable stage and the print cartridge holder, wherein the camera is positioned such that the movable stage and the print die are within a field of view of the camera;

a processor to calculate a first offset of the well plate and a second offset of the print die based on an image of the movable stage and the print die captured by the camera and to control movement of the movable stage in accordance with the first offset and the second offset; and

a memory to store a template of the print die, wherein the template is compared to the image of the movable stage and the print die captured by the camera to calculate the second offset.

2 . The apparatus of claim 1 , further comprising:

a light source located below the movable stage to emit light towards the camera.

3 . The apparatus of claim 2 , wherein the well plate comprises a fiducial that is captured by the camera to measure the first offset.

4 . The apparatus of claim 3 , wherein the fiducial is optically clear to allow the light emitted by the light source to pass through towards the camera.

5 . The apparatus of claim 1 , wherein the second offset comprises a rotational offset and a translational offset.

6 . A method, comprising:

receiving, by a processor, an image of a fiducial of a well plate captured by a camera;

calculating, by the processor, a first offset associated with the well plate based on the image of the fiducial;

receiving, by the processor, an image of a print die captured by the camera;

calculating, by the processor, a second offset associated with the print die based on the image of the print die,

wherein calculating the second offset comprises:

determining, by the processor, an edge of the print die; and

determining, by the processor, an amount of rotational offset based on a comparison of the edge of the print die to an edge of a field of view of the camera;

receiving, by the processor, a request to dispense a fluid into a well of the well plate via the print die; and

moving, by the processor, a movable stage holding the well plate to position the well below a nozzle of the print die that is to emit the fluid, wherein an amount of movement of the movable stage is compensated by the first offset and the second offset.

7 . The method of claim 6 , wherein calculating the first offset comprises:

determining, by the processor, an amount of movement along a vertical axis and a horizontal axis to align a center of the fiducial to a center of a field of view of the camera.

8 . The method of claim 6 , further comprising:

rotating, by the processor, the image of the print die by the amount of rotational offset;

determining, by the processor, a center of the print die; and

determining, by the processor, a translational offset based on an amount of movement along a vertical axis and a horizontal axis to align the center of the print die to a center of a field of view of the camera.

9 . The method of claim 6 , wherein the amount of movement is further compensated by a nozzle offset of the nozzle.

10 . A non-transitory computer readable storage medium encoded with instructions which, when executed, cause a processor of an apparatus to:

determine offsets associated with a well plate and a print die based on images captured of a fiducial of the well plate and the print die, the processor to determine the offsets at least by determining a nozzle offset of the print die based on a look up table for the print die;

store the offsets in a memory; and

adjust movements of a movable stage that is to hold the well plate based on the offsets to eject a fluid from a nozzle on the print die into a selected well of the well plate.

11 . The non-transitory computer readable storage medium of claim 10 , further causing the processor to:

determine offsets of a jetting bias.

12 . The non-transitory computer readable storage medium of claim 11 , wherein the instructions to cause the processor to determine offsets of the jetting bias comprise instructions to cause the processor to:

cause the print die to dispense a plurality of test droplets on a substrate at desired locations; and

measure an amount of movement along a vertical axis and a horizontal axis to align a center of the plurality of test droplets to a center of the desired locations.