Patent EP0183680A2 successfully refreshed from Google Patents.
EP0183680A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Thermal recording system and method
Assignee: Polaroid Corp
•
Filing: 1985-11-27
•
Granted: —
•
Expires: 2005-11-27
Abstract
Abstract A closed loop thermal recording system and method are provided for recording an image represented by pixel areas of varied density on a thermally sensitive recording medium. The system receives electronic image information defining a desired density for each pixel area and applies thermal energy to selected pixel areas to record in each a dot having an initial size that is smaller than necessary to achieve its desired density. The density levels provided by the initial dots are measured and compared to desired density. Based on these comparisons, additional thermal energy is applied to progressively to increase dot size until a predetermined density comparison value is achieved for each selected pixel area.
Inventors
- 👤 Irving Erlichman
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 15:54
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40025; H04N1/4005; H04N1/40031
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
168 words
A thermal recording system for recording an image represented by pixel areas of varied density on a thermally sensitive recording medium of the type wherein dot size increases with increase amounts of thermal energy applied to form a dot, said recording system comprising: means for receiving image information indicative of a desired density for each pixel area of the desired image; means operable for applying thermal energy to selected pixel areas on the recording medium in accordance with said image information to form a dot in each selected pixel area having an initial size smaller than needed to achieve its said desired density; evaluating means including means for monitoring the density of each selected pixel area and means for comparing the monitored density with said desired density; and means responsive to said evaluating means for regulating said energy applying means to progressively increase the dot size in each of said selected pixel areas until a predetermined value of density comparison is achieved for each said selected pixel area.
Claim 2
Dependent Claim
168 words
A thermal recording system for recording an image represented by pixel areas of varied density on a thermally sensitive recording medium of the type wherein dot size increases with increase amounts of thermal energy applied to form a dot, said recording system comprising: means for receiving image information indicative of a desired density for each pixel area of the desired image; means operable for applying thermal energy to selected pixel areas on the recording medium in accordance with said image information to form a dot in each selected pixel area having an initial size smaller than needed to achieve its said desired density; evaluating means including means for monitoring the density of each selected pixel area and means for comparing the monitored density with said desired density; and means responsive to said evaluating means for regulating said energy applying means to progressively increase the dot size in each of said selected pixel areas until a predetermined value of density comparison is achieved for each said selected pixel area.
Claim 3
Dependent Claim
78 words
The recording system of claim 1 wherein the recording medium includes an opaque base layer and a thermally sensitive recording layer on one side of the base layer and wherein said thermal energy applying means is configured apply thermal energy to a side of the base layer opposite the one side and said monitoring means is located on an opposite side so that it may monitor the selected pixel areas without being obstructed by said energy applying means.
Claim 4
Dependent Claim
51 words
The recording system of claim 1 wherein said recording medium includes a base layer and a thermally sensitive recording layer on one side of the base layer and wherein said thermal energy applying means and said monitoring means are located on the same side of the medium facing the recording layer.
Claim 5
Dependent Claim
31 words
The recording system of claim 3 wherein said thermal energy applying means includes means for emitting light onto the recording layer where it is converted to thermal energy to effect recording.
Claim 6
Dependent Claim
36 words
The recording system of claim 2 wherein the thermally sensitive medium is a thermally sensitive recording sheet and wherein said energy applying means and said monitoring means are located on opposite sides of the recording sheet.
Claim 7
Dependent Claim
40 words
The recording system of claim 3 wherein the thermally sensitive medium is a thermally sensitive recording sheet and wherein said energy applying means and said monitoring means are located in facing relation to the same side of the recording sheet.
Claim 8
Dependent Claim
24 words
The recording system of claim 1 wherein said monitoring means includes electro-optical means for sensing the reflected light level of each selected pixel area.
Claim 9
Dependent Claim
26 words
The recording system of claim 1 wherein said means for receiving image information is configured to receive said information in the form of electronic image signals.
Claim 10
Dependent Claim
45 words
The recording system of claim 1 wherein the thermal energy initially applied to each selected pixel area, to form a dot of said initial size is subsequently progressively increased to increase the size of each dot until said predetermined value of density comparison is achieved.
Claim 11
Dependent Claim
74 words
The recording system of claim 1 wherein said energy applying means includes a thermal print head having a plurality of individually addressible heating elements for recording dots in corresponding ones of a plurality of pixal areas on the recording medium in registration with said heating elements, and said monitoring means includes a plurality of individual addressible photodiodes for sensing the reflected light level of the corresponding pixel as an indication of pixel area density.
Claim 12
Dependent Claim
18 words
The recording system of claim 10 further including means for advancing the medium relative to said heating elements.
Claim 13
Dependent Claim
37 words
The recording system of claim 11 wherein said pixel areas are of a size different from said photodiodes in said array and said system further includes optical means for providing a focused image of each pixel area.
Claim 14
Dependent Claim
20 words
The recording system of claim 1 further including a light source for illuminating pixel areas monitored by said sensing means.
Claim 15
Dependent Claim
41 words
The recording system of claim 1 wherein said energy applying means is configured to engage the medium and said system further includes pressure applying means for urging at least a portion of the medium into engagement with said energy applying means.
Claim 16
Dependent Claim
21 words
The recording system of claim 1 further including means establishing a feed back loop between said energy applying and monitoring means.
Claim 17
Independent Claim
155 words
A method of thermally recording an image represented by pixel areas of varied density on a thermally sensitive recording medium of the type wherein dot size increases with increased amounts of thermal energy applied to form a dot, said recording method comprising the steps of: providing image information indicative of a desired density for each pixel area of the desired image; applying thermal energy to selected pixel areas on the recording medium in accordance with said image information to form a dot in each having an initial size smallei±than necessary to achieve its said desired density; monitoring the density of each selected pixel area; comparing the monitored density of each selected pixel area to its said desired density; and based on said comparison, applying additional thermal energy to said selected pixel area to progressively increase dot size in each until a predetermined value of density comparison is achieved and thereupon terminating application of thermal energy.
Claim 18
Independent Claim
155 words
A method of thermally recording an image represented by pixel areas of varied density on a thermally sensitive recording medium of the type wherein dot size increases with increased amounts of thermal energy applied to form a dot, said recording method comprising the steps of: providing image information indicative of a desired density for each pixel area of the desired image; applying thermal energy to selected pixel areas on the recording medium in accordance with said image information to form a dot in each having an initial size smallei±than necessary to achieve its said desired density; monitoring the density of each selected pixel area; comparing the monitored density of each selected pixel area to its said desired density; and based on said comparison, applying additional thermal energy to said selected pixel area to progressively increase dot size in each until a predetermined value of density comparison is achieved and thereupon terminating application of thermal energy.
Claim 19
Dependent Claim
43 words
The method of claim 16 wherein the medium includes a base sheet having a thermal recording layer on the front side thereof and said thermal energy is applied to the back side of said base sheet for transmission therethrough to said recording layer.
Claim 20
Dependent Claim
23 words
The method of claim 17 wherein the density of each selected pixel area is monitored on the front side of the recording medium.
Claim 21
Dependent Claim
42 words
The method of claim 16 wherein there is a delay between the application of thermal energy to form said dot of initial size and said monitoring of pixel area density to allow for an increase in dot size due to thermal inertia.
Claim 22
Dependent Claim
28 words
The method of claim 16 wherein density is monitored optically and said method further includes the step of illuminating said selected pixel areas to facilitate such optical monitoring.
Claim 23
Dependent Claim
52 words
The method of claim 16 wherein said thermal energy is applied with thermal energy applying means configured to record only a portion of said image at a time and said method includes the further step of advancing the medium relative to said energy applying means to record successive portions of said image.
Claim 24
Dependent Claim
27 words
The method of claim 16 wherein density is monitored with an array of photodetectors and thermal energy is applied with an array of electrically resistive heating elements.
Claim 25
Dependent Claim
43 words
The method of claim 22 wherein said pixel areas are of a size different from said photodetectors and said method includes the further step of optically focusing an image of said selected pixel areas on corresponding ones of said photodetectors in said array.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.