Patent ID: 8186798

Claim:
An ink jet recording apparatus that records information by discharging ink on a recording medium using a recording head, the ink jet recording apparatus comprising: a recording head having a discharge port, the recording head being configured to discharge ink from the discharge port in response to driving of a heater that produces thermal energy; a temperature measuring unit configured to measure a temperature adjacent to the heater, and to, when the heater is driven in response to an application of a drive voltage for discharging ink from the discharge port, measure a change in temperature adjacent to the heater; and a determining unit configured to determine whether a predetermined point to be calculated by second-order differentiation is present within a range where a temperature falls after a temperature rises in a curve representing the change in temperature measured by the temperature measuring unit, wherein the determining unit determines whether the predetermined point is present based on a result of calculation of the change in temperature in a predetermined time range including a timing at which the predetermined point is present in a normal discharge state, wherein the determining unit determines that a discharge state of the discharge port is normal when the predetermined point is present and the discharge state of the discharge port is not normal when the predetermined point is not present.