US4814787A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for compensating temperature to a thermal head
Assignee: Fujifilm Holdings Corp
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Filing: 1987-01-16
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Granted: 1989-03-21
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Expires: 2007-01-16
Abstract
Abstract The relation between an input energy at a thermal head and recording density in a thermographical recording system varies inconveniently by the ambient temperature or the head temperature, and moreover, the slope of the relation varies by the temperatures. Therefore, even if the input energy at the thermal head alone is precisely and minutely controlled, it is heretofore difficult to obtain the desired recording density if the temperature fluctuates. Even if the temperature at the thermal head is detected by a temperature sensor, and compensation is made based on the detected temperature, it is still difficult to achieve recording of high quality because there inevitably arise a time lag between the detected temperature and the real temperature of a heating resistor which is recording images. This invention method enables high quality recording by estimating a real temperature at the heating resistor out of detected temperatures obtained with a temperature sensor and compensating the temperature based upon the estimated temperature.
Inventors
- 👤 Atsuhiro Doi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:55
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/315; B41J2/32; B41J2/35; B41J2/355; B41J2/36; B41J2/365
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
78 words
A method for compensating temperature in a thermal recording wherein a temperature at a thermal head is detected to compensate an influence of the temperature in the thermal recording, which comprises the steps of: conducting said temperature detection for plural times; obtaining a difference between said plural detected temperatures; multiplying the difference with coefficients; adding the multiplied value to a detected temperature; and estimating a real temperature at the thermal head for compensation based upon the added value.
Claim 2
Independent Claim
78 words
A method for compensating temperature in a thermal recording wherein a temperature at a thermal head is detected to compensate an influence of the temperature in the thermal recording, which comprises the steps of: conducting said temperature detection for plural times; obtaining a difference between said plural detected temperatures; multiplying the difference with coefficients; adding the multiplied value to a detected temperature; and estimating a real temperature at the thermal head for compensation based upon the added value.
Claim 3
Dependent Claim
61 words
The method for compensating temperature in a thermal recording as claimed in claim 1, further including the steps of: preparing a reference input energy for the thermal head; measuring a thermal head temperature and an ambient temperature at a time of the thermal recording; and compensating the reference input energy based upon a function of said measured thermal and ambient temperatures.
Claim 4
Dependent Claim
24 words
The method for compensation temperature in a thermal recording as claimed in claim 2 wherein said temperature detection is conducted at a predetermined interval.
Claim 5
Dependent Claim
39 words
The method for compensating temperature in a thermal recording as claimed in claim 3 wherein said detected temperatures are converted from analog to digital, stored in a memory, and read out at a next detection to obtain the difference.
Claim 6
Independent Claim
127 words
A method for compensating temperature on a thermal head in a thermographical recording device which thermally records images with a heating element applied with electricity, which comprises the steps of: preparing a reference input energy for the thermal head; measuring a thermal head temperature and an ambient temperature at a time of the thermal recording; and compensating the reference input energy based upon a linear function of said measured thermal and ambient temperatures, wherein said compensating operation operation is carried out by the equation below: ##EQU2## wherein: D O denotes a reference recorded density, D a desired density, J O the reference input energy, J input energy, T S the ambient temperature, T TH the head temperature, γ O a reference correction coefficient, and a, b coefficients.
Claim 7
Independent Claim
127 words
A method for compensating temperature on a thermal head in a thermographical recording device which thermally records images with a heating element applied with electricity, which comprises the steps of: preparing a reference input energy for the thermal head; measuring a thermal head temperature and an ambient temperature at a time of the thermal recording; and compensating the reference input energy based upon a linear function of said measured thermal and ambient temperatures, wherein said compensating operation operation is carried out by the equation below: ##EQU2## wherein: D O denotes a reference recorded density, D a desired density, J O the reference input energy, J input energy, T S the ambient temperature, T TH the head temperature, γ O a reference correction coefficient, and a, b coefficients.
Claim 8
Independent Claim
85 words
A method for compensating temperature on a thermal head in a thermographical recording device which thermally records images with a heating element applied with electricity, which comprises the steps of: preparing a reference input energy for the thermal head; measuring a thermal head temperature and an ambient temperature at a time of the thermal recording; preparing a data table in advance; and compensating the reference input energy based upon a linear function of said measured thermal and ambient temperatures by referring to said data table.
Claim 9
Independent Claim
85 words
A method for compensating temperature on a thermal head in a thermographical recording device which thermally records images with a heating element applied with electricity, which comprises the steps of: preparing a reference input energy for the thermal head; measuring a thermal head temperature and an ambient temperature at a time of the thermal recording; preparing a data table in advance; and compensating the reference input energy based upon a linear function of said measured thermal and ambient temperatures by referring to said data table.
References Cited (Backward Citations)
US4391535A
Cited
US4536774A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-20 | 1992-09-19 | 1993-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-20 | 1996-09-19 | 1997-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-20 | 2000-09-19 | 2001-03-21 | $7700.00 | Window Closed / Lapsed |