Invalidity dossier
US 5589889
Image memory device and method of operating same
Current assignee: Fujifilm Corp
Added 9/17/2026, 1:40:19 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 5,589,889 A
Title: Image memory device and method of operating same
Inventor: Yoshiki Kawaoka
Assignee/current owner on record: Fuji Photo Film Co., Ltd. (original assignee); later reassignments to FUJIFILM HOLDINGS CORPORATION and FUJIFILM CORPORATION are listed on the source page.
Key dates (as listed on the source page; priority date is expressly an assumption, not a legal conclusion):
- Priority date: 1991-04-16
- Application filed: 1994-04-29 (application no. US08/235,221)
- Publication/grant: 1996-12-31
- Status: Expired – Lifetime (anticipated expiration 2013-12-31)
Purpose: To provide a general-purpose image memory device and operating method that lets a user employ any desired image pick-up means (e.g., video camera) and any desired display means, while still obtaining excellent tone reproducibility.
Plain-language scope (from the supplied text): An analog video signal from an image pick-up device is converted to digital image data by an A/D converter. A rewritable input look-up table (LUT) applies a reverse gamma correction, converting the pick-up device's non-linear incident-light luminance vs. output-signal characteristics into linear characteristics. The corrected data is stored in a memory. A rewritable output LUT applies a gamma correction to data read from the memory, conforming the linear data to the display's non-linear input-signal vs. output-luminance characteristics; the corrected data is converted back to analog by a D/A converter and sent to the display. A processing means (host CPU) creates the reverse-gamma data and gamma data according to the pick-up device and display actually used, and can also access/process the stored image data.
Not established by the excerpt: The complete text, all claims, the full description, and any drawing details are omitted; the excerpt does not establish claim scope, prosecution history, prior art, validity, infringement, or the accuracy of ownership/reassignment listings.
Generated 10/1/2026, 10:03:10 PM
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PTAB challenges
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Assignment history
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Prior art
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Obviousness
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Extensions
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Derivative works
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