Abstract:
The input energies provided to a print head of a thermal printer are adjusted based on the temperature of a platen in the thermal printer. The platen temperature may be measured by a sensor or predicted by a platen temperature model. Such a model may derive the predicted platen temperature from an observed temperature of a heat sink in the thermal printer. A thermal history control algorithm may use the platen temperature, whether actual or predicted, to compensate for the platen temperature by adjusting the input energies.
Abstract:
The present invention provides a thermal printer in which the temperature of the thermal printing head can be modulated by means of an auxiliary heat sink, and methods for printing using such a thermal printer.
Abstract:
A method for controlling the print density of individual heating elements of a thermal print head array determines respective energy values for each heating element in response to image pixel data to be printed, multiplies determined energy values by a respective predetermined correction factor for one or more respective heating elements for improving print density consistency between individual heating elements, and dithers adjusted energy values from the step of multiplying as a function of adjacent image pixels.
Abstract:
A multicolor direct thermal imaging method wherein a multicolor image is formed in a thermal imaging member comprising at least first and second different image-forming compositions and a thermal printer for use in practicing the method. Heat is applied to at least the second image-forming composition while the first image-forming composition is at a first baseline temperature (T1) to form an image in at least the second image-forming composition, and heat is applied to at least the first image-forming composition while it is at a second baseline temperature (T2) to form an image in at least the first image-forming composition, wherein T1 is different from T2.
Abstract:
A multicolor direct thermal imaging method and an imaging member for use therein, wherein a multicolor image is formed in a thermal imaging member having at least two different image-forming compositions capable of forming two different colors. Heat is used to form an image in the first color at a first speed of travel of the thermal imaging member with respect to the source of heat, and heat is used to form an image in the second color at a second speed of travel of the thermal imaging member with respect to the source of heat, where the first speed of travel and the second speed of travel are different from each other.
Abstract:
A method for controlling the print density of individual heating elements of a thermal print head array determines respective energy values for each heating element in response to image pixel data to be printed, multiplies determined energy values by a respective predetermined correction factor for one or more respective heating elements for improving print density consistency between individual heating elements, and dithers adjusted energy values from the step of multiplying as a function of adjacent image pixels.
Abstract:
In one aspect of the invention there is disclosed a multicolor thermal imaging system wherein different heating elements on a thermal print head can print on different color-forming layers of a multicolor thermal imaging member in a single pass. The line-printing time is divided into segments, each of which is divided into a plurality of subintervals. All of the pulses within the segments have the same energy. In one embodiment, every pulse has the same amplitude and duration. Different colors are selected for printing during the different segments by varying the fraction of subintervals that contain pulses. This technique allows multiple colors to be printed using a thermal print head with a single strobe signal line. Pulsing patterns may be chosen to reduce the coincidence of pulses provided to multiple print head elements, thereby reducing the peak power requirements of the print head.
Abstract:
The present invention provides a thermal printer in which the temperature of the thermal printing head can be modulated by means of an auxiliary heat sink, and methods for printing using such a thermal printer.
Abstract:
The input energies provided to a print head of a thermal printer are adjusted based on the temperature of a platen in the thermal printer. The platen temperature may be measured by a sensor or predicted by a platen temperature model. Such a model may derive the predicted platen temperature from an observed temperature of a heat sink in the thermal printer. A thermal history control algorithm may use the platen temperature, whether actual or predicted, to compensate for the platen temperature by adjusting the input energies.
Abstract:
A method estimates the temperature of a thermal print head element during printing. In one embodiment, the temperature is estimated using the resistance of the thermal print head element, which typically changes with the print head element temperature. The change in resistance of the print head element is exploited to indirectly estimate the temperature of the print head element.