Print head apparatus capable of temperature sensing

A print head apparatus capable of temperature sensing, the print head apparatus comprising:

• an ink ejector, coupled to an enabling signal and a selection signal for selecting the ink ejector, the ink ejector comprising:
• a nozzle;
• a heating module for selectively heating ink in the ink ejector so that ink droplets are ejected from the nozzle, the heating module comprising:
• a heating device, disposed in close proximity to the nozzle and coupled to the selection signal, for heating up the ink in the ink ejector so that ink droplets are ejected from the nozzle;
• and
• an enabling gate coupled to the enabling signal and the heating device, for selectively activating the heating device;
• and
• a temperature sensing module for selectively producing a measured temperature signal indicative of a temperature of the ink in close proximity to the nozzle, the temperature sensing module comprising:
• a temperature sensor, disposed in close proximity to the nozzle, for measuring the temperature of the ink in close proximity to the nozzle and producing the measured temperature signal indicative of the temperature of the ink in close proximity to the nozzle;
• and
• a detection gate, coupled to the temperature sensor and the selection signal, for selectively outputting the measured temperature signal, the detection gate comprising:
• a first transistor coupled to the selection signal;
• and
• a second transistor, coupled to the first transistor and the selection signal;
• wherein when the enabling signal is active, and the selection signal is active and indicates that the ink ejector is selected, the enabling gate activates the heating module so that the heating device heats up;
• wherein when the selection signal is active and indicates that the ink ejector is selected, the detection gate outputs the measured temperature signal.

A print head apparatus capable of temperature sensing, the print head apparatus comprising

• an ink ejector, coupled to an enabling signal and a selection signal including first and a second signals for selecting the ink ejector, the ink ejector comprising:
• a nozzle;
• a heating module for selectively heating ink in the ink ejector so that ink droplets are ejected from the nozzle;
• and
• a temperature sensing module for selectively producing a measured temperature signal indicative of a temperature of the ink in close proximity to the nozzle, the temperature sensing module comprising:
• a temperature sensor, disposed in close proximity to the nozzle, for measuring the temperature of the ink in close proximity to the nozzle and producing the measured temperature signal indicative of the temperature of the ink in close proximity to the nozzle;
• and
• a detection gate, coupled to the temperature sensor and the selection signal, for selectively outputting the measured temperature signal, the detection gate comprising:
• a first transistor coupled to the first signal;
• and
• a second transistor, coupled to the first transistor and the second signal;
• wherein when the enabling signal is active, and the selection signal is active and indicates that the ink ejector is selected, the heating module is activated so that ink droplets are ejected from the nozzle;
• wherein when the selection signal is active and indicates that the ink ejector is selected, the temperature sensing module outputs the measured temperature signal indicative of the temperature of the ink in close proximity to the nozzle.

A method for temperature measurement in a print head apparatus including a plurality of ink ejectors, the method being capable of avoiding erroneously driving the ink ejectors when performing temperature measurement, wherein each ink ejector includes a nozzle, a heating module, and a temperature sensing module, the heating module includes a heating device and an enabling gate, the temperature sensing module includes a temperature sensor and a detection gate, the method comprising the steps of:

• selectively applying a plurality of selection signals that are active to the ink ejectors;
• disabling the heating modules of the selected ink ejectors so as to stop ink droplets to be ejected from the nozzles of the selected ink ejectors by applying an enabling signal that is not active to the heating modules of the selected ink ejectors, and outputting at least one measured temperature signal indicative of the temperature of ink in close proximity to the nozzle of a corresponding selected ink ejector by the temperature sensing module of the corresponding selected ink ejector, if temperature measurement is desired and ink ejection is not desired;
• and
• enabling the heating modules of the selected ink ejectors so as to eject ink droplets from the nozzles of the selected ink ejectors by applying the enabling signal that is active to the heating modules of the selected ink ejectors if ink ejection is desired;
• wherein in the step of disabling the heating modules, each selection signal includes a first signal and a second signal, each heating module of the corresponding selected ink ejector is disabled by using the corresponding enabling gate having a first transistor and a second transistor coupled to the first transistor, and the enabling signal that is not active is applied to the second transistor of the corresponding enabling gate to disable the corresponding heating device, thereby avoiding erroneously driving the ink ejectors when performing temperature measurement.

A method for temperature measurement in a print head apparatus including a plurality of ink ejectors, the method being capable of avoiding erroneously driving the ink ejectors when performing temperature measurement, wherein each ink ejector includes a nozzle, a heating module, and a temperature sensing module, the heating module includes a heating device and an enabling gate, the temperature sensing module includes a temperature sensor and a detection gate, the method comprising the steps of:

• selectively applying a plurality of selection signals that are active to the ink ejectors;
• disabling the heating modules of the selected ink ejectors so as to stop ink droplets to be ejected from the nozzles of the selected ink ejectors by applying an enabling signal that is not active to the heating modules of the selected ink ejectors, and outputting at least one measured temperature signal indicative of the temperature of ink in close proximity to the nozzle of a corresponding selected ink ejector by the temperature sensing module of the corresponding selected ink ejector, if temperature measurement is desired and ink ejection is not desired;
• and
• enabling the heating modules of the selected ink ejectors so as to eject ink droplets from the nozzles of the selected ink ejectors by applying the enabling signal that is active to the heating modules of the selected ink ejectors if ink ejection is desired;
• wherein in the step of disabling the heating modules, each selection signal has a first signal and a second signal, said at least one measured temperature signal indicative of the temperature of ink in close proximity to the nozzle of the corresponding selected ink ejector is outputted by the corresponding temperature sensor via the corresponding detection gate having a first transistor and a second transistor coupled to the first transistor, the first and the second signals are applied to the first and the second transistors respectively.