Claims
- 1. A method for controlling an amount of heat generated by a thermal head device, the thermal head device including:
- a thermal head having a plurality of heat-generating elements arranged in a row, successive elements of the plurality of heat-generating elements being alternately designated as an odd-number element and an even-number element;
- a calculation circuit for generating a power-on time for each heat-generating element of said thermal head;
- a plurality of latches, each of the plurality of latches being connected to an associated group of the plurality of heat-generating elements; and
- a control circuit for controlling said plurality of latches such that each of the plurality of latches applies power to selected elements of the associated group of heat-generating elements for a duration equal the power-on time output from the calculation circuit
- wherein said method comprises the steps of:
- (a) calculating a power-on time for a selected element of the plurality of heat-generating elements in units of time shorter than a minimum power-on time, the selected element being connected to a first latch of the plurality of latches;
- (b) determining whether the calculated power-on time is equal to an integral multiple of the minimum power-on time or not;
- (c) if the calculated power-on time is equal to such an integral multiple:
- (i) writing the calculated power-on time directly to said first, latch as the power-on time for said selected element, and
- (ii) applying electrical current to the selected element via said first latch for a period equal to said power-on time; and
- (d) if the calculated power-on time is not equal to such an integral multiple:
- (i) determining whether the selected element is an odd-number element or an even-number element;
- (ii) changing the calculated power-on time for the selected element to an integral value obtained by rounding up fractions below a decimal point of the calculated power-on time if the selected element is a first one of an odd-numbered element and an even-number element, and to an integral value obtained by rounding down fractions below a decimal point of the calculated power-on time if the selected element is a second one of an odd-number element and an even-number element;
- (iii) writing the changed calculated power-on time directly to said first latch as the power-on time for said selected element; and
- (iv) applying electrical current to the selected element via said first latch for a period equal to said power-on time.
- 2. The method of claim 1, wherein the step of calculating the calculated power-on time includes rounding the calculated power-on time to nearest 1/2 times the minimum power-on time.
- 3. A method for controlling an amount of heat generated by a thermal head device the thermal head device including:
- a thermal head having a plurality of heat-generating elements arranged in a row, successive elements of the plurality of heat-generating elements being alternately designated as an odd-number element and an even-number element;
- a calculation circuit for generating a power-on time for each heat-generating element of said thermal head;
- a plurality of latches, each of the plurality of latches being connected to an associated group of the plurality of heat-generating elements; and
- a control circuit for controlling said plurality of latches such that each of the plurality of latches applies power to selected elements of the associated group of heat-generating elements for a duration equal the power-on time output from the calculation circuit,
- wherein said method comprises the steps of:
- (a) calculating a power-on time for a selected element of the plurality of heat-generating elements in units of time shorter than a minimum power-on time, the selected element being connected to a first latch of the plurality of latches;
- (b) determining whether the calculated power-on time is equal to an integral multiple of the minimum power-on time or not;
- (c) if the calculated power-on time is equal to such an integral multiple:
- (i) writing the calculated power-on time directly to said first latch as the power-on time for said selected element, and
- (ii) applying electrical current to the selected element via said first latch for a period equal to said power-on time; and
- (d) if the calculated power-on time is not equal to such an integral multiple:
- (i) determining whether the selected element is an odd-number element or an even-number element;
- (ii) changing the calculated power-on time for the selected element to an integral value obtained by rounding up fractions below a decimal point of the calculated power-on time if the selected element is an odd-number element, and to an integral value obtained by rounding down fractions below a decimal point of the calculated power-on time if the selected element is an even-number element;
- (iii) writing the changed calculated power-on time directly to said first latch as the power-on time for said selected element; and
- (iv) applying electrical current to the selected element via said first latch for a period equal to said power-on time.
- 4. A controlling method according to claim 3, wherein the power-on time is calculated in power-on time units corresponding to half the minimum power-on time.
- 5. A method for controlling an amount of heat generated by a thermal head device, the thermal head device including:
- a thermal head having a plurality of heat-generating elements arranged in a row, successive elements of the plurality of heat-generating elements being alternately designated as an odd-number element and an even-number element;
- a calculation circuit for generating a power-on time for each heat-generating element of said thermal head;
- a plurality of latches, each of the plurality of latches being connected to an associated group of the plurality of heat-generating elements; and
- a control circuit for controlling said plurality of latches such that each of the plurality of latches applies power to selected elements of the associated group of heat-generating elements for a duration equal the power-on time output from the calculation circuit,
- wherein said method comprises the steps of:
- (a) calculating a power-on time for a selected element of the plurality of heat-generating elements in units of time shorter than a minimum power-on time, the selected element being connected to a first latch of the plurality of latches;
- (b) determining whether the calculated power-on time is equal to an integral multiple of the minimum power-on time or not;
- (c) if the calculated power-on time is equal to such an integral multiple:
- (i) writing the calculated power-on time directly to said first latch as the power-on time for said selected element, and
- (ii) applying electrical current to the selected element via said first latch for a period equal to said power-on time; and
- (d) if the calculated power-on time is not equal to such an integral multiple:
- (i) determining whether the selected element is an odd-number element or an even-number element;
- (ii) changing the calculated power-on time for the selected element to an integral value obtained by rounding up fractions below a decimal point of the calculated power-on time if the selected element is an even-number element, and to an integral value obtained by rounding down fractions below a decimal point of the calculated power-on time if the selected element is an odd-number element;
- (iii) writing the changed calculated power-on time directly to said first latch as the power-on time for said selected element; and
- (iv) applying electrical current to the selected element via said first latch for a period equal to said power-on time.
- 6. A controlling method according to claim 5, wherein the power-on time is calculated in power-on time units corresponding to half the minimum power-on time.
- 7. A printing method for a thermal head device, the thermal head device including:
- a thermal head having a plurality of heat-generating elements arranged in a row, successive elements of the plurality of heat-generating elements being alternately designated as an odd-number element and an even-number element;
- a calculation circuit for generating a power-on time for each heat-generating element of said thermal head;
- a plurality of latches, each of the plurality of latches being connected to an associated group of the plurality of heat-generating elements; and
- a control circuit for controlling said plurality of latches such that each of the plurality of latches applies power to selected elements of the associated group of heat-generating elements for a duration equal the power-on time output from the calculation circuit,
- wherein said method comprises the steps of:
- (a) calculating a power-on time for a selected element of the plurality of heat-generating elements in units of time shorter than a minimum power-on time, the selected element being connected to a first latch of the plurality of latches;
- (b) determining whether the calculated power-on time is equal to an integral multiple of the minimum power-on time;
- (c) if the calculated power-on time is equal to such an integral multiple:
- (i) writing the calculated power-on time directly to said first latch as the power-on time for said selected element, and
- (ii) applying electrical current to the selected element via said first latch for a period equal to said power-on time; and
- (d) if the calculated power-on time is not equal to such an integral multiple:
- (i) determining whether the selected element is an odd-number element or an even-number element,
- (ii) changing the calculated power-on time for the selected element to an integral value obtained by rounding up fractions below a decimal point of the calculated power-on time if the selected element is a first one of an odd-numbered element and an even-number element, and to an integral value obtained by rounding down fractions below a decimal point of the calculated power-on time if the selected element is a second one of an odd-number element and an even-number element,
- (iii) writing the changed calculated power-on time directly to said first latch as the power-on time for said selected element,
- (iv) applying electrical current to the selected element via said first latch for a period equal to said power-on time, and
- (v) applying said thermal head to a recording medium.
Priority Claims (1)
Number |
Date |
Country |
Kind |
3-227312 |
Sep 1991 |
JPX |
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Parent Case Info
This application is a continuation of application Ser. No. 07/938,788, now abandoned filed Sep. 1, 1992.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4816843 |
Sasaki |
Mar 1989 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
938788 |
Sep 1992 |
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