Three-dimensional object generation

1. A method of cooling at least one agent distributor comprising at least one fluid ejection die, a fluid reservoir to store fluid agent, and a heat sink partially inside of the fluid reservoir and partially outside of the fluid reservoir, wherein the at least one fluid ejection die is in indirect thermal contact with the heat sink via the fluid agent, the method comprising:

cooling the heat sink with a cooling fluid;

removing heat from the fluid agent stored in the fluid reservoir via a direct thermal contact between the heat sink and the fluid agent; and

removing heat from the at least one fluid ejection die by heat conduction via the direct thermal contact between the heat sink and the fluid agent.

2. An apparatus for generating a three-dimensional object comprising

at least one-agent distributor comprising a fluid reservoir to store fluid agent and at least one fluid ejection die to selectively eject the fluid agent in a build material area; and

a cooling system in a direct thermal contact with the fluid agent in the fluid reservoir to remove heat therefrom, wherein

the cooling system comprises a heat sink that is partially inside of the fluid reservoir and partially outside of the fluid reservoir, and is to remove heat from the at least one fluid ejection die via the direct thermal contact between the heat sink and the fluid agent in the fluid reservoir.

3. The apparatus of claim 2 comprising at least one first electromagnetic radiation emitter to emit first radiation towards the build material area to pre-heat build material in the build material area, wherein the three-dimensional object is generated from the build material, wherein the at least one fluid ejection die is located above the build material area, and wherein the at least one fluid agent is cooled by the heat sink.

4. The apparatus of claim 2 further comprising at least one second electromagnetic radiation emitter to emit second radiation towards the build material area to fuse build material into a three-dimensional object, wherein

the agent distributor selectively ejects a first fluid agent in at least one pattern defined in data received by the apparatus to generate at least one solidification portion of the build material corresponding to at least one cross section of the object to be generated and wherein the first fluid agent absorbs the second radiation of the second electromagnetic radiation emitter and converts the absorbed second radiation to thermal energy, thereby at least partially fusing the at least one solidification portion of the build material in proximity of the first fluid agent when exposed to the second radiation; and

the agent distributor selectively ejects a second fluid agent in at least one farther pattern, wherein said further pattern comprises at least one detailing portion of the build material, the build material is exposed to the second radiation of the at least one second electromagnetic radiation emitter, wherein the second fluid agent at least partially prevents the build material in the at least one detailing portion to coalesce, thereby creating spaces in a completed object where the build material is less cohesive than untreated build material, such that a breakability of the build material along the at least one detailing portion is enhanced.

5. An agent distributor comprising at least one fluid ejection die, wherein

the agent distributor comprises a heat sink and a fluid reservoir to store fluid agent, wherein the heat sink is partially inside of the fluid reservoir and partially outside of the fluid reservoir;

the fluid agent is to be cooled by the heat sink via direct thermal contact between the fluid agent and the heat sink; and

the at least one fluid ejection die is in indirect thermal contact with the heat sink via the fluid agent.

6. The agent distributor of claim 5 , wherein the fluid reservoir is segmented vertically into at least two chambers extending horizontally by at least one partition wall to keep at least two individual fluid agents separated.

7. The agent distributor of claim 5 , wherein

the heat sink comprises a cooling circuit to cool the agent distributor from inside the fluid reservoir,

a first agent distributor side panel comprises at least one opening, and

at least one tube comprising cooling fluid extends through the at least one opening in the first agent distributor side panel to supply the cooling circuit with the cooling fluid.

8. The agent distributor of claim 7 , wherein

the cooling circuit is formed by the at least one tube;

the cooling circuit extends through the fluid reservoir;

the cooling circuit is passed through the at least one fluid agent; and

the at least one fluid agent is cooled by heat conduction through the at least one tube.

9. The agent distributor of claim 8 , wherein

the at least one tube extends through the first agent distributor side panel;

the at least one tube extends substantially horizontally through a first chamber of the fluid reservoir;

the at least one tube passes from the first chamber of the fluid reservoir through at least one partition wall to a second chamber of the fluid reservoir,

the at least one tube extends substantially horizontally through the second chamber of the fluid reservoir, and

the at least one tube extends through a second opening in the first agent distributor side panel.

10. The agent distributor of claim 8 , wherein

a first tube extends through a first opening in a first agent distributor side panel;

the first tube extends substantially horizontally through a first chamber of the fluid reservoir:

the first tube passes through a third opening in a second agent distributor side panel;

a second tube extends through a second opening in the first agent distributor side panel;

the second tube extends substantially horizontally through a second chamber of the fluid reservoir; and

the second tube passes through a fourth opening in the second agent distributor side panel.

11. The agent distributor of claim 10 , wherein the heat sink comprises a heat conducting plate with fins embedded in a third agent distributor side panel extending substantially horizontally therealong and exposed to an interior and an exterior of the fluid reservoir.

12. The agent distributor of claim 11 , wherein the fins on the exterior of the fluid reservoir are cooled by a coolant circuit or by ambient air.

13. The agent distributor of claim 8 , wherein the heat sink comprises a heat conducting plate with fins embedded in a third agent distributor side panel extending substantially horizontally therealong and exposed to an interior and an exterior of the fluid reservoir, wherein the fins on the exterior of the fluid reservoir are cooled by a coolant circuit or by ambient air.

14. The agent distributor of claim 11 , wherein the heat conducting plate with fins is insulated and/or passivated on the interior of the fluid reservoir, where the fins come in contact with the at least one printing agent, and wherein the heat conducting plate with fins is insulated and/or passivated on the exterior of the fluid reservoir, where the fins come in contact with a coolant of the coolant circuit.

15. The agent distributor of claim 5 , wherein the at least one fluid ejection die is surrounded by a heat reflecting coating or a heat reflecting material that reflects heat radiation from a build material area below the agent distributor back onto the build material area.