INK JET PRINTING APPARATUS, METHOD FOR DETERMINING PRINT MEDIUM, AND METHOD FOR DETERMINING INK EJECTION AMOUNT

Abstract

The present invention provides an ink jet printing apparatus that can prevent the erroneous selection of the print mode, which may degrade the image quality, without imposing any special burden on the user. Specifically, the present invention forms a dot on a print medium to sense the ability of the print medium to absorb printing ink. The ink jet printing apparatus has reading devices for reading the dot and print mode selecting devices for setting the optimum print mode from a plurality of print modes according to the shape of the dot.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an example of an ink jet printing apparatus in accordance with the present invention;

FIG. 2 is a perspective view showing an essential part of the ink jet printing apparatus shown in FIG. 1;

FIG. 3 is a perspective view showing a carriage used in the example shown in FIG. 2;

FIGS. 4A and 4B are diagrams illustrating a process of reading a dot using reading means provided in the carriage shown in FIG. 3 in accordance with a first embodiment;

FIG. 5 is a flowchart showing a method for determining a print mode in accordance with the first embodiment of the present invention;

FIG. 6 is a plan view showing the relationship between a dot and an area sensed by a photodiode in accordance with the first embodiment;

FIG. 7 is a graph of signal data output by the photodiode in accordance with the first embodiment of the present invention;

FIG. 8 is a flowchart showing operations of an optimum print mode determining circuit in accordance with a second embodiment of the present invention;

FIG. 9 is a diagram of a warning window displayed on a display screen if a print mode selected by an ink jet printing apparatus does not match a print mode selected by a user in accordance with the second embodiment of the present invention;

FIGS. 10A and 10B are diagrams illustrating a process of reading dots using reading means provided in a carriage in accordance with the second embodiment;

FIG. 11 is a flowchart showing operations of an optimum ejection amount determining circuit for ink in accordance with a third embodiment of the present invention; and

FIG. 12 is a graph of signal data output by a photodiode 25 in accordance with the third embodiment of the present invention.

Claims

1. An ink jet printing apparatus providing with an ink jet print head that ejects printing ink to a print medium for performing printing, and setting a plurality of print modes for plural types of the print medium, said apparatus comprising: dot forming means for forming a dot by applying a liquid droplet to the print medium;reading means for reading said dot formed according to an ability of the print medium to absorb the printing ink; and print mode setting means for setting a print mode according to a signal read by said reading means.

2. An ink jet printing apparatus having an ink jet print head that ejects printing ink to a print medium for printing, the apparatus comprising: dot forming means for forming a dot by applying a liquid droplet to the print medium;reading means for reading said dot formed on the basis of an ability of the print medium to absorb the printing ink; andink ejection amount determining means for determining an ink ejection amount of the printing ink, the ink ejection amount being suitable for the print medium on the basis of a signal read by said reading means.

3. The ink jet printing apparatus according to claim 1, wherein saidliquid droplet is a treatment liquiddifferent from the printing ink.

4. The ink jet printing apparatus according to claim 3, wherein said treatment liquid is mixed with the printing ink to make the printing ink insoluble to water.

5. The ink jet printing apparatus according to claim 1, wherein said liquid droplet is the printing ink.

6. The ink jet printing apparatus according to claim 1, wherein said reading means comprises light emitting means for irradiating said dot with light and light receiving means for receiving light emitted by said dot on which the light emitted by the light emitting means impinges.

7. The ink jet printing apparatus according to claim 6, wherein when irradiated with invisible region light, said dot emits light that can be sensed by said light receiving means.

8. The ink jet printing apparatus according to claim 7, wherein said liquid droplet contains a luminescent substance that emits lights when irradiated with said invisible region light.

9. The ink jet printing apparatus according to claim 7, wherein said invisible region light is ultraviolet radiation.

10. The ink jet printing apparatus according to claim 6, wherein said print medium is an ink absorptivity sensing print medium that emits light when irradiated with light, and said liquid droplet contains a light absorbing substance that absorbs applied light.

11. The ink jet printing apparatus according to claim 10, wherein when irradiated with the invisible region light, said ink absorptivity sensing print medium emits light that can be sensed by the light receiving means.

12. The ink jet printing apparatus according to claim 11, wherein said ink absorptivity sensing print medium contains a luminescent substance that emits light when irradiated with said invisible region light.

13. The ink jet printing apparatus according to claim 10, wherein said light absorbing substance is an ultraviolet absorbing substance.

14. The ink jet printing apparatus according to claim 1, further comprising suspending means for suspending printing executed by said ink jet printing apparatus wherein if a print mode set by said print mode setting means does not match a print mode selected by a user.

15. The ink jet printing apparatus according to claim 1, wherein said print mode setting means sets the print mode on the basis of a half-value width of peak of a signal intensity read by said reading means.

16. The ink jet printing apparatus according to claim 2, wherein said ink ejection amount determining means determines an ink ejection amount on the basis of a half-value width of peak of a signal intensity read by said reading means.

17. A method for determining a print medium in an ink jet printing apparatus that ejects printing ink to the print medium, the method comprising: a dot forming step of forming a dot by applying a liquid droplet to the print medium;a dot reading step of reading said dot formed on the basis of an ability of the print medium to absorb the printing ink; anda print medium determining step of determining the print medium on the basis of a signal read in said dot reading step.

18. A method for determining an ink ejection amount of an ink jet printing apparatus that ejects printing ink to the print medium, the method comprising: a dot forming step of forming a dot by applying a liquid droplet to the print medium;a dot reading step of reading said dot formed on the basis of an ability of the print medium to absorb the printing ink; andan ink ejection amount determining step of determining an ink ejection amount of the printing ink, the ink ejection amount being suitable for the print medium on the basis of the dot read in said dot reading step.

19. An ink jet printing apparatus using a print head that ejects a liquid to form an image on a print medium, the apparatus comprising: ejecting means for ejecting the liquid to the print medium;irradiating means for irradiating the liquid ejected by said ejecting means with the invisible region light;light receiving means for receiving reflected light corresponding applied light reflected by said liquid or light emitted by said liquid in response to the applied light; andsetting means for setting a print mode for formation of an image on the print medium on the basis of the quantity of light received by said light receiving means.

20. The ink jet printing apparatus according to 19, wherein said setting means sets the print mode according to an ability of the print medium to absorb the liquid which ability can be determined on the basis of the quantity of light received.