A LIST OF PATENTS (Below)--Following up on my previous post, it turns out that 3 of Lexar's 15 "returns", when you do a search on "Lexar" for patents, do not name them as assignee, and the 5,388,083 patent in dispute is not "their's" either. And, "Lexar's" patent 5838614 turns up when a search for "Sandisk" is run. Suppositions: (1) Lexar must have bought or obtained a license for the patent from Citrix. (2)Sandisk is mentioned somewhere in 5838614, or the presence of the lawsuit is crossreferenced in the patent search engine; (3) The search method is only an approximation of anything. With that last caveat, I can state:
Lexar patents are referenced by others 11 times, with patent 5596526 being the only one mentioned by another patent holder more than once (it is mentioned in 8 other patents).
Sandisk patents are referenced by other patents 158 times. Its patent 5602987 (subject of Sandisk's plaintiff action) is mentioned 26 times!
The effect of patents seems to be cumulative. Having just one patent in an area wouldn't seem to provide much of a barrier to others, unless it is extremely fundamental (in which case it will be referenced a lot). Just one patent will normally allow others to find work-arounds, and avoid the disputed patent. Having lots of patents makes it harder and harder for others to find ways to make a technology work without breaching some of those patents.
It would seem that Sandisk's patent position is far stronger than Lexar's. Its patents are much more important.
Lexar's tactics seem to be harass Sandisk into a better cross-licensing deal.
Following is from the Patent Office search. I have inserted after the patent number how many times each patent is referenced in another patent.
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Results of Search in 1976-1999 db for:
sandisk: 55 patents.
Hits 1 through 50 out of 55
Refs--PAT. NO.
Title
1 5,965,913
Dense vertical programmable read only memory cell structures and processes for making them
2 5,937,425
Flash file system optimized for page-mode flash technologies
3 5,936,971
Multi-state flash EEprom system with cache memory
4 5,933,328
Compact mechanism for removable insertion of multiple integrated circuit cards into portable and other
electronic devices
5 5,930,815
Moving sequential sectors within a block of information in a flash memory mass storage architecture
6 5,930,167
Multi-state non-volatile flash memory capable of being its own two state write cache
7 5,910,925
EEPROM with split gate source side injection
8 5,910,915
EEPROM with split gate source side injection
9 5,907,856
Moving sectors within a block of information in a flash memory mass storage architecture
10 5,890,192
Concurrent write of multiple chunks of data into multiple subarrays of flash EEPROM
11 5,887,145
Removable mother/daughter peripheral card
12 5,883,409
EEPROM with split gate source side injection
13 5,877,986
Multi-state Flash EEprom system on a card that includes defective cell substitution
14 5,877,975
Insertable/removable digital memory apparatus and methods of operation thereof
15 5,867,429
High density non-volatile flash memory without adverse effects of electric field coupling between adjacent floating gates
16 5,867,417
Computer memory cards using flash EEPROM integrated circuit chips and memory-controller systems
17 5,862,080
Multi-state flash EEprom system with defect handling
18 5,847,996-1 Ref Made
Eeprom with split gate source side injection
19 5,847,425
Dense vertical programmable read only memory cell structures and processes for making them
20 5,838,614-Lexar's Patent comes up under search of "Sandisk"
Identification and verification of a sector within a block of mass storage flash memory
21 5,815,426-1 Ref Made
Adapter for interfacing an insertable/removable digital memory apparatus to a host data part
22 5,806,070
Device and method for controlling solid-state memory system
23 5,798,968-1 Ref Made
Plane decode/virtual sector architecture
24 5,786,988
Integrated circuit chips made bendable by forming indentations in their back surfaces flexible packages
thereof and methods of manufacture
25 5,778,418-1 Ref Made
Mass computer storage system having both solid state and rotating disk types of memory
26 5,776,810-1 Ref Made
Method for forming EEPROM with split gate source side injection
27 5,756,385-3 Refs Made
Dense flash EEPROM cell array and peripheral supporting circuits formed in deposited field oxide with the
use of spacers
28 5,747,359
Method of patterning polysilicon layers on substrate
29 5,719,808-7 Refs Made
Flash EEPROM system
30 5,712,179-1 Ref Made
Method of making triple polysilicon flash EEPROM arrays having a separate erase gate for each row of
floating gates
31 5,693,570-2 Refs Made
Process for manufacturing a programmable power generation circuit for flash EEPROM memory systems
32 5,678,562-2 Refs Made
Ambulatory physiological monitor with removable disk cartridge and wireless modem
33 5,677,872-1 Refs Made
Low voltage erase of a flash EEPROM system having a common erase electrode for two individual erasable
sectors
34 5,671,229-8 Refs Made
Flash eeprom system with defect handling
35 5,663,901-12 Refs Made
Computer memory cards using flash EEPROM integrated circuit chips and memory-controller systems
36 5,661,053-1 Refs Made
Method of making dense flash EEPROM cell array and peripheral supporting circuits formed in deposited
field oxide with the use of spacers
37 5,659,550-2 Refs Made
Latent defect handling in EEPROM devices
38 5,657,332-3 Refs Made
Soft errors handling in EEPROM devices
39 5,654,217
Dense flash EEPROM cell array and peripheral supporting circuits formed in deposited field oxide with the
use of spacers
40 5,621,685-4 Refs Made
Programmable power generation circuit for flash EEPROM memory systems
41 5,602,987-26 Refs Made
Flash EEprom system
42 5,596,532-6 Refs Made
Flash EEPROM self-adaptive voltage generation circuit operative within a continuous voltage source range
43 5,595,924-2 Refs Made
Technique of forming over an irregular surface a polysilicon layer with a smooth surface
44 5,592,420-2 Refs Made
Programmable power generation circuit for flash EEPROM memory systems
45 5,579,259-4 Refs Made
Low voltage erase of a flash EEPROM system having a common erase electrode for two individually
erasable sectors
46 5,568,424-3 Refs Made
Programmable power generation circuit for flash EEPROM memory systems
47 5,563,825-3 Refs Made
Programmable power generation circuit for flash eeprom memory systems
48 5,535,328-23 Refs Made
Non-volatile memory system card with flash erasable sectors of EEprom cells including a mechanism for
substituting defective cells
49 5,534,456-5 Refs Made
Method of making dense flash EEPROM cell array and peripheral supporting circuits formed in deposited
field oxide with sidewall spacers
50 5,532,964-2 Refs Made
Method and circuit for simultaneously programming and verifying the programming of selected EEPROM
Cells
51 5,532,962-1 Refs Made
Soft errors handling in EEPROM devices
52 5,512,505-5 Refs Made
Method of making dense vertical programmable read only memory cell structure
53 5,508,971-10 Refs Made
Programmable power generation circuit for flash EEPROM memory systems
54 5,504,760-9 Refs Made
Mixed data encoding EEPROM system
55 5,495,442-8 Refs Made
Method and circuit for simultaneously programming and verifying the programming of selected EEPROM
cells
Results of Search in 1976-1999 db for:
Lexar: 15 patents.
Hits 1 through 15 out of 15
PAT. NO.
Title
1 5,953,737
Method and apparatus for performing erase operations transparent to a solid state storage system
2 5,930,815
Moving sequential sectors within a block of information in a flash memory mass storage architecture
3 5,928,370
Method and apparatus for verifying erasure of memory blocks within a non-volatile memory structure
4 5,924,113
Direct logical block addressing flash memory mass storage architecture
5 5,907,856
Moving sectors within a block of information in a flash memory mass storage architecture
6 5,845,313-1 Ref Made
Direct logical block addressing flash memory mass storage architecture
7 5,838,614
Identification and verification of a sector within a block of mass storage flash memory
8 5,835,935-1 Ref Made
Method of and architecture for controlling system data with automatic wear leveling in a semiconductor
non-volatile mass storage memory
9 5,818,781-1 Ref Made
Automatic voltage detection in multiple voltage applications
10 5,818,350
High performance method of and system for selecting one of a plurality of IC chip while requiring minimal
select lines
11 5,645,945-Not Lexar's!
Multi-layer films made from copolyamides
12 5,606,660
Method and apparatus for combining controller firmware storage and controller logic in a mass storage
system
13 5,596,526-1 Ref Made
Non-volatile memory system of multi-level transistor cells and methods using same
14 4,679,191-Not Lexar's!
Variable bandwidth switching system
15 4,587,651-Not Lexar's!
Distributed variable bandwidth switch for voice, data, and image communications |
