Image forming apparatus and gradation correction test chart

1. An image forming apparatus comprising:

print data generating unit for generating gradation correction test chart print data to juxtapose and draw a basis density pattern having a basis density of a yellow color of various colors including the yellow color used for multicolor printing and a plurality of reference density patterns having respective densities of the yellow color to be compared with the basis density and additionally draw a contrast effect pattern composed of colors having a contrast effect on the yellow color for the basis density pattern and the reference density patterns of the yellow color;

printing unit for printing a gradation correction test chart including a yellow color gradation correction pattern in which the basis density pattern and the plurality of reference density patterns are juxtaposed and printed and the contrast effect pattern is additionally printed, based on the gradation correction test chart print data generated by the print data generating unit;

receiving unit for receiving an input of a density adjustment value of any pattern based on a shading comparison of the basis density pattern and the reference density patterns by a user's visual observation of the density correction test chart printed by the printing unit; and

gradation correcting unit for performing a gradation correction of any pattern based on the density adjustment value of any pattern received by the receiving unit,

wherein the print data generating unit generates yellow color gradation correction test chart print data to juxtapose and draw a basis density pattern having a basis density for each density and a plurality of reference density patterns having respective densities to be compared with the basis density, embed and draw a first embedded contrast effect pattern composed of a blue color for the basis density pattern and the reference density patterns of a density range exceeding a predetermined density, and embed and draw a second embedded contrast effect pattern composed of a black color for the basis density pattern and the reference density patterns of a density range less than the predetermined density, based on a print instruction of the yellow color gradation correction test chart, and

wherein the printing unit prints a yellow color gradation correction test chart in which the basis density pattern and the plurality of reference density patterns are juxtaposed and printed, the first embedded contrast effect pattern composed of the blue color for the basis density pattern and the reference density patterns of a density range exceeding a predetermined density is embedded and printed, and the second embedded contrast effect pattern composed of the black color for the basis density pattern and the reference density patterns of a density range less than the predetermined density is embedded and printed, based on the yellow color gradation correction test chart print data.

2. The image forming apparatus according to claim 1 ,

wherein the print data generating unit generates the gradation correction test chart print data to juxtapose and draw a basis density pattern having a basis density of a corresponding color of the various colors and a plurality of reference density patterns having respective densities of the corresponding color to be compared with the basis density and draw a contrast effect pattern composed of a blue color around the basis density pattern and the reference density patterns of the yellow color, based on a print instruction of the gradation correction test chart, and

wherein the printing unit prints the gradation correction test chart in which the basis density pattern and the plurality of reference density patterns are juxtaposed and printed and the contrast effect pattern composed of the blue color around the basis density pattern and the reference density patterns of the yellow color is printed, based on the gradation correction test chart print data.

3. The image forming apparatus according to claim 1 ,

wherein the print data generating unit generates yellow color gradation correction test chart print data to juxtapose and draw a basis density pattern having a basis density for each density range of a yellow color and a plurality of reference density patterns having respective densities to be compared with the basis density, draw a first contrast effect pattern composed of a blue color around the basis density pattern and the reference density patterns of a density range exceeding a predetermined density, and draw a second contrast effect pattern composed of a black color around the basis density pattern and the reference density patterns of a density range less than the predetermined density, based on a print instruction of the yellow color gradation correction test chart, and

wherein the printing unit prints a yellow color gradation correction test chart in which the basis density pattern and the plurality of reference density patterns are juxtaposed and printed, the first contrast effect pattern composed of the blue color with around the basis density pattern and the reference density patterns of a density range exceeding a predetermined density is printed, and the second contrast effect pattern composed of the black color with around the basis density pattern and the reference density patterns of a density range less than the predetermined density is printed, based on the yellow color gradation correction test chart print data.

4. The image forming apparatus according to claim 3 ,

wherein the print data generating unit generates yellow color gradation correction test chart print data to juxtapose and draw a basis density pattern having a basis density for each density range of a yellow color and a plurality of reference density patterns having respective densities to be compared with the basis density, embed and draw a first embedded contrast effect pattern composed of a blue color for the basis density pattern and the reference density patterns of a density range exceeding a predetermined density, and embed and draw a second embedded contrast effect pattern composed of a black color for the basis density pattern and the reference density patterns of a density range less than the predetermined density, based on a print instruction of the yellow color gradation correction test chart, and

wherein the printing unit prints a yellow color gradation correction test chart in which the basis density pattern and the plurality of reference density patterns are juxtaposed and printed, the first embedded contrast effect pattern composed of the blue color for the basis density pattern and the reference density patterns of a density range exceeding a predetermined density is embedded and printed, and the second embedded contrast effect pattern composed of the black color for the basis density pattern and the reference density patterns of a density range less than the predetermined density is embedded and printed, based on the yellow color gradation correction test chart print data.

5. The image forming apparatus according to claim 1 ,

wherein the print data generating unit generates yellow color gradation correction test chart print data to concentrically and alternately arrange and draw a basis density pattern having a basis density for each density range of a yellow color and reference density patterns having respective continuously varying densities to be compared with the basis density, embed and draw a first embedded contrast effect pattern composed of a blue color for the basis density pattern and the reference density patterns of a density range exceeding a predetermined density, and embed and draw a second embedded contrast effect pattern composed of a black color for the basis density pattern and the reference density patterns of a density range less than the predetermined density, based on a print instruction of the yellow color gradation correction test chart, and

wherein the printing unit prints a yellow color gradation correction test chart in which the basis density pattern and the reference density patterns are concentrically and alternately arranged and printed, the first embedded contrast effect pattern composed of a blue color for the basis density pattern and the reference density patterns of a density range exceeding a predetermined density is embedded and printed, and the second embedded contrast effect pattern composed of a black color for the basis density pattern and the reference density patterns of a density range less than the predetermined density is embedded and printed, based on the yellow color gradation correction test chart print data.

6. A gradation correction test chart printed by an image forming apparatus including receiving unit for receiving an input of a density adjustment value of any pattern based on a shading comparison of a basis density pattern and reference density patterns by a user's visual observation of the gradation correction test chart, and gradation correcting unit for performing a gradation correction of any pattern based on the density adjustment value of any pattern received by the receiving unit,

wherein the image forming apparatus juxtaposes and prints a basis density pattern having a basis density of a yellow color of various colors including the yellow color used for multicolor printing and a plurality of reference density patterns having respective densities of the yellow color to be compared with the basis density and additionally prints a contrast effect pattern composed of colors to increase a contrast effect on the yellow color for the basis density pattern and the reference density patterns of the yellow color,

wherein the print data generating unit generates yellow color gradation correction test chart print data to juxtapose and draw a basis density pattern having a basis density for each density range of a yellow color and a plurality of reference density patterns having respective densities to be compared with the basis density, embed and draw a first embedded contrast effect pattern composed of a blue color for the basis density pattern and the reference density patterns of a density range exceeding a predetermined density, and embed and draw a second embedded contrast effect pattern composed of a black color for the basis density pattern and the reference density patterns of a density range less than the predetermined density, based on a print instruction of the yellow color gradation correction test chart, and

wherein the printing unit prints a yellow color gradation correction test chart in which the basis density pattern and the plurality of reference density patterns are juxtaposed and printed, the first embedded contrast effect pattern composed of the blue color for the basis density pattern and the reference density patterns of a density range exceeding a predetermined density is embedded and printed, and the second embedded contrast effect pattern composed of the black color for the basis density pattern and the reference density patterns of a density range less than the predetermined density is embedded and printed, based on the yellow color gradation correction test chart print data.