Method for evaluating discharge amount of liquid droplet discharging device

1. A discharge amount evaluation method of a liquid droplet discharging device that is performed to evaluate a discharge amount of a liquid discharged by the liquid droplet discharging device, the liquid including at least one of a solution prepared by dissolving a solute in a solvent and a dispersion prepared by dispersing a dispersoid in a dispersion medium, the method comprising:

discharging the liquid by the liquid droplet discharging device on a receiving layer of a test piece, the test piece including the receiving layer that absorbs at least one of the solvent and the dispersion medium as components included in the liquid and a base layer that is abutted with the receiving layer and that does not absorb the at least one component absorbed by the receiving layer in the components included in the liquid; and

evaluating the discharge amount of the liquid based on a result obtained by evaluating an area of an absorbing portion where the at least one absorbed component has spread in the receiving layer.

2. The discharge amount evaluation method of a liquid droplet discharging device according to claim 1 , wherein, in the evaluation step, the area is evaluated by an image-pickup processing that picks up an image of the absorbing portion and an analyzing processing that analyzes the image.

3. The discharge amount evaluation method of a liquid droplet discharging device according to claim 2 , wherein, in the analyzing processing, a threshold is set using a gradation of the absorbing portion in the image and a gradation of a peripheral region around the absorbing portion in the image to detect an outline of the absorbing portion based on the threshold so as to evaluate the area of the absorbing portion.

4. The discharge amount evaluation method of a liquid droplet discharging device according to claim 3 , wherein, in the analyzing processing, the gradation of the absorbing portion is a gradation of a part except for a rim of the absorbing portion in the image, and the gradation of the peripheral region is a gradation of a part except for a region adjacent to the absorbing portion in the image.

5. The discharge amount evaluation method of a liquid droplet discharging device according to claim 3 , wherein, in the analyzing processing, the gradation of the absorbing portion and the gradation of the peripheral region are obtained by excluding a gradation changing region in the image.

6. The discharge amount evaluation method of a liquid droplet discharging device according to claim 3 , wherein, in the evaluation step, the image pickup processing is performed a plurality of times by changing a focal distance, and in the analyzing processing, the threshold is set using a plurality of images obtained by performing the image pickup processing the plurality of times.

7. The discharge amount evaluation method of a liquid droplet discharging device according to claim 3 , wherein, in the analyzing processing, the threshold is a mean value between the gradation of the absorbing portion and the gradation of the peripheral region.

8. The discharge amount evaluation method of a liquid droplet discharging device according to claim 3 , wherein, in the analyzing processing, a first temporary evaluation of the area is performed using a first threshold that is an integer obtained by rounding up figures after decimal point in the threshold and a second temporary evaluation of the area is performed using a second threshold that is an integer obtained by rounding down the figures after decimal point in the threshold, as well as a value evaluating the area in the first temporary evaluation is weighted in inverse proportion to a difference between the threshold and the first threshold and a value evaluating the area in the second temporary evaluation is weighted in inverse proportion to a difference between the threshold and the second threshold, so as to evaluate the area.