Printing fluid developer assembly

1. A binary printing fluid developer assembly, comprising:

a developer roller to receive a printing fluid and transfer a portion of the printing fluid to a photoconductive member;

a number of electrodes to create an electrical potential bias between the number of electrodes and the developer roller;

a cleaner roller to remove an amount of printing fluid from the developer roller; and

a sponge roller to clean the cleaner roller, wherein a first electrode is curved to match a circumference of the sponge roller;

wherein:

on a first side of the sponge roller, a curved gap is maintained between the sponge roller and the first electrode; and

on a second and opposite side of the sponge roller, the sponge roller contacts a wiper wall.

2. The binary printing fluid developer assembly of claim 1 , wherein the sponge roller is compressed a distance between 0 to 0.75 millimeters by the cleaner roller.

3. The binary printing fluid developer assembly of claim 1 , wherein the sponge roller has a diameter of between 19 and 17 millimeters.

4. The binary printing fluid developer assembly of claim 1 , wherein the number of electrodes comprises multiple electrodes alongside the first side of the sponge roller.

5. The binary printing fluid developer assembly of claim 1 , wherein the wiper wall comprises a squeezing bump downstream of an interface between the cleaner roller and sponge roller to squeeze out an amount of printing fluid from a surface of the sponge roller before the surface of the sponge roller interfaces with the cleaner roller.

6. The binary printing fluid developer assembly of claim 5 , wherein the squeezing of the sponge roller by the squeezing bump of the wiper wall causes a pumping effect to pump printing fluid into and out of the sponge roller.

7. The binary printing fluid developer assembly of claim 1 , wherein the number of electrodes have a negative electrical potential to draw the printing fluid towards the developer roller.

8. The binary printing fluid developer assembly of claim 7 , wherein the developer roller has a negative electrical potential that is less negative than the negative electrical potential of the number of electrodes.

9. The binary printing fluid developer assembly of claim 8 , wherein the cleaner roller has a negative electrical potential that is less negative than the negative electrical potential of the developer roller.

10. The binary printing fluid developer assembly of claim 9 , wherein the negative electrical potential of the cleaner roller changes over time.

11. The binary printing fluid developer assembly of claim 1 , wherein:

the cleaner roller is to rotate in an opposite direction relative to the developer roller; and

the sponge roller is to rotate in a same direction relative to the cleaner roller.

12. A system for remixing excess printing fluid, comprising:

a binary printing fluid developer assembly, comprising:

a number of electrodes to create an electrical potential bias between the number of electrodes and a developer roller;

a cleaner roller to clean a first amount of printing fluid from a surface of the developer roller;

a sponge roller to remove the first amount of printing fluid from the cleaner roller and remix the first amount of printing fluid with a second amount of printing fluid;

wherein:

a first electrode is curved to match a circumference of the sponge roller;

the sponge roller has an interference with the cleaner roller of between 0 and 0.75 millimeters;

on a first side of the sponge roller, a curved gap is maintained between the sponge roller and the first electrode; and

on a second and opposite side of the sponge roller, the sponge roller contacts a wiper wall.

13. The system of claim 12 wherein:

the binary printing fluid developer assembly further comprises at least one electrode passing immediately alongside the sponge roller; and

the gap is to allow an amount of mixed first and second amount of printing fluid to be passed away from the developer roller.

14. The system of claim 13 wherein the at least one electrode comprises a protuberance on a side of the at least one electrode where the sponge roller is placed and wherein the gap is maintained between the protuberance and the sponge roller.

15. The system of claim 12 , wherein the binary printing fluid developer assembly further comprises a doctor blade to remove the first amount of printing fluid from off of a surface of the cleaner roller.

16. The system of claim 12 , wherein a vertical plane through an axis of the developer roller does not intersect the sponge roller.

17. A printing system, comprising:

a number of printing fluid developers, each printing fluid developer comprising:

a developer roller;

an electrode to create an electrical potential bias with the developer roller and transfer the printing fluid to the developer roller;

a cleaner roller to clean an amount of printing fluid from the developer roller; and

a sponge roller to remove an amount of printing fluid from the cleaner roller, wherein a first electrode is curved to match a circumference of the sponge roller;

wherein:

on a first side of the sponge roller, a curved gap is maintained between the sponge roller and the first electrode; and

on a second and opposite side of the sponge roller, the sponge roller contacts a wiper wall.

18. The printing system of claim 17 wherein an interface of the sponge roller to the cleaner roller has an overlap of between 0 and 0.75 millimeters.

19. The printing system of claim 17 , wherein each of the developer rollers of the printing fluid developers interface, circumferentially, around a photoconductive roller with each of the developer rollers providing a different type of printing fluid to the developer roller.

20. The printing system of claim 17 , wherein the sponge roller has a diameter of between 19 and 17 millimeters.