Test apparatus for evaluating electrical properties of liquid toner and test method for the same

A test apparatus to evaluate the electrical properties of a liquid toner, comprising:

• a conductive flat panel on which the liquid toner is arranged;
• a developing roller arranged in contact with the conductive flat panel;
• a moving means rotatably moving the developing roller parallel to the conductive flat panel from a first position to a second position to planarize the liquid toner;
• a power supply device applying a voltage the conductive flat panel;
• and
• a voltage tester provided at a following portion with respect to a moving direction of the developing roller to move together with the developing roller, testing a voltage of the liquid toner planarized by the developing roller on the conductive flat panel at the first and second positions.

A test method to evaluate the electrical properties of a liquid toner, comprising:

• arranging the liquid toner on a conductive flat panel;
• planarizing the liquid toner using a roller-tester to which a voltage is applied;
• testing a voltage change of the planarized liquid toner across the conductive flat panel using the roller-tester,
• wherein the roller-tester obtains a maximum voltage value and a time taken to reach 0 V from the maximum voltage, and compares the maximum voltage value and the time taken to reach 0 V with a maximum voltage value and a time to reach 0 V of a liquid toner with a known printing quality to obtain a voltage change value to predict a printing quality of the liquid toner being evaluated.

A test method to evaluate the electrical properties of a test liquid toner, comprising:

• arranging the test liquid toner on a conductive flat panel;
• planarizing the test liquid toner using a roller;
• measuring a voltage of the test liquid toner at points across the conductive flat panel after being planarized;
• obtaining a maximum voltage and a time taken to reach 0 V from 0 V through the maximum voltage from the measured voltage of the test liquid toner;
• and
• comparing the maximum voltage and the time taken to reach 0 V for the test liquid toner with a maximum voltage and a time taken to reach 0 V for a known liquid toner with a known printing quality to predict a printing quality of the test liquid toner.

A test apparatus to evaluate electrical properties of a liquid toner, comprising:

• a conductive flat panel on which the liquid toner is arranged;
• a roller-tester arranged on the conductive flat panel to flatten the liquid toner over a predetermined distance on the conductive flat panel and to test a voltage of the liquid toner flattened by the roller;
• and
• a power supply supplying a voltage to the roller and the conductive flat panel,
• wherein the roller-tester obtains a maximum voltage value and a time taken to reach 0 V from 0 V through the maximum voltage and compares the maximum voltage value and the time taken to reach 0 V with a maximum voltage value and a time of a liquid toner with a known printing quality to reach 0 V to obtain a voltage change value to predict a printing quality of the liquid toner tested.

A test apparatus to evaluate the electrical properties of a liquid toner, comprising:

• a conductive flat panel on which the liquid toner is arranged;
• and
• a roller-tester to planarize the liquid toner on the conductive flat panel, apply a voltage across the planarized liquid toner and test a voltage change of the planarized liquid toner across the conductive flat panel,
• wherein a voltage tested at a first position and a voltage tested at a second position are compared to estimate a printing quality of the liquid toner.