Black toners containing infrared transmissive and reflecting colorants

1. A toner formulation comprising:

a binder;

an infrared absorbing black pigment at a concentration of 0.25-2.0% by weight; and

a plurality of infrared transmissive pigments other than a black pigment, wherein said plurality of infrared transmissive pigments are configured to provide a black color.

2. The toner formulation of claim 1 wherein said plurality of infrared transmissive pigments configured to provide a black color comprise two or more of the following: blue pigment, cyan pigment, green pigment, yellow pigment, orange pigment, brown pigment, red pigment, magenta pigment, and violet pigment.

3. The toner formulation of claim 1 wherein said black color comprises a color having a chroma C* of less than or equal to 15.0 for all half-tone shade levels printed on white paper.

4. The toner formulation of claim 2 wherein said blue pigment absorbs at a wavelength of 510-700 nm, said cyan pigment absorbs at a wavelength of 550-700, said green pigment absorbs at a wavelength of 400-450 nm and 580-700 nm, said yellow pigment absorbs at a wavelength of 400-500 nm, said orange pigment absorbs at a wavelength of 400-550, said brown pigment absorbs at a wavelength of 400-580 nm, said red pigment absorbs at a wavelength of 400-580 nm, said magenta pigment absorbs at a wavelength of 500-580 nm, and said violet pigment absorbs at a wavelength of 500-600 nm.

5. The toner formulation according to claim 1 wherein said plurality of infrared transmissive pigments comprise one of the following color combinations:

(a) cyan and orange;

(b) cyan and red; and

(c) blue and red.

6. The toner formulation of claim 1 wherein said plurality of infrared transmissive pigments is present at a level of less than or equal to 15.0% by weight.

7. The toner formulation of claim 1 wherein said formulation exhibits a bulk reflectivity at about 940 nanometers, for toner particle sizes of 5.5 to 10 microns, of greater than 7.5% and less than or equal to 60%.

8. The toner formulation of claim 1 wherein said infrared absorbing black pigment comprises a pigment selected from the group consisting of carbon black, oxidic black pigment, iron oxide (Fe 3 O 4 ), spinel black [Cu(Cr,Fe) 2 )O 4 ], organic black colorants and mixtures thereof.

9. The toner formulation of claim 1 wherein said formulation is contained in an image forming apparatus.

10. The toner formulation of claim 1 wherein said formulation is contained in a printer cartridge.

11. A toner formulation comprising:

a binder;

an infrared absorbing carbon black at a concentration of 0.25-2.0% by weight; and

a plurality of infrared transmissive pigments other than a black pigment at a level of less than or equal to 15.0% by weight, wherein said plurality of infrared transmissive pigments are configured to provide a black color and respond to a toner patch sensor to indicate a mass per unit area of unfused toner of 0.1-1.5 mg/cm 2 .

12. The toner formulation of claim 11 wherein said formulation exhibits a bulk reflectivity of greater than 6.0% for a portion the wavelength range 850-2000 nm.

13. The toner formulation of claim 11 wherein said formulation is contained in an image forming apparatus.

14. The toner formulation of claim 11 wherein said formulation is contained in a printer cartridge.

15. A method for calibrating an image forming device using a toner patch sensor and a toner formulation comprising:

depositing a plurality of toner patches onto a control surface, wherein said toner patches include a first toner patch, including a first toner, a second toner patch including said first toner deposited over a second toner and a third toner patch including said second toner, wherein said first toner comprises a binder and an IR absorbing black pigment at a concentration of 0.25-2.0% by weight, including one or more infrared transmissive pigments, wherein said infrared transmissive pigments are configured to provide a black color;

measuring signals indicative of reflectivity of said plurality of toner patches and the reflectivity of said control surface by emitting light of a given wavelength in the infrared spectrum and detecting the amount of incident light reflected from said plurality of toner patches and said control surface; wherein said first toner patch exhibits a first reflectivity R 1 at said given wavelength, said second toner patch exhibits a second reflectivity R 2 at said given wavelength, said third toner patch exhibits a third reflectivity R 3 at said given wavelength, said control surface exhibits a fourth reflectivity R control at said given wavelength, wherein R control ≠R 3 ; and

adjusting an operating parameter based upon said measurements.

16. The method of claim 15 further comprising determining a ratio (Ratio (A:B)) according to the following relationship:

R

2

-

R

1

R

3

-

R

control

=

Ratio

⁡

(

A

:

B

)

.

and adjusting an operating parameter of said image forming device based on said ratio.

17. The method of claim 16 wherein said toner formulation is capable of responding to a toner patch sensor to indicate a mass per unit area of toner of about 0.1-1.5 g/cm 2 .

18. The toner formulation according to claim 1 wherein said plurality of infrared transmissive pigments comprises pigment blue 15:3 and pigment red 185 at a ratio of about 1:2.