US 5,025,483 A · System for scanning documents without loss of image data

Abstract

A document processing system directs documents at a high rate of speed past an optical scanner which captures written information on the documents as video image data. The video image data is directed over a data channel to a host computer system where the data is stored on a mass data storage device for subsequent retrieval. A buffer is provided between the scanner and the data channel, which receives data a rate which varies in relation to the amount of information present on the documents. Data is extracted from the buffer at a rate which is limited by the host computer's channel transfer rate. A control means is associated with the buffer and is operable for controlling a hierarchy of actions ranging from slowing down the incoming data stream to stopping the data stream altogether in order to prevent any loss of video image data due to overfilling of the buffer.

Claims10

Dependent claims

A system for capturing video image data from documents comprising

document feed means for feeding successive documents from a hopper to a document transport,
document transport means for receiving each successively fed document and advancing the respective documents past a document scanner,
document scanner means for scanning the successively transported documents and for generating therefrom video image data, the quantity of which may vary widely depending upon the amount of information present on the document,
a buffer for receiving and temporarily storing video image data,
data input means for directing video image data obtained from said document scanner means into said buffer,
data output means cooperating with said buffer for extracting video image data from the buffer, and
control means cooperating with said buffer and operable to perform a hierarchy of control actions over the flow of video image data into said buffer to assure data integrity and prevent loss of data, said control means including
a first control action means operable in response to the level of stored data in said buffer reaching a first threshold for effecting stopping of the feed of additional documents by said document feed means while allowing documents already in the document transport to continue in process, and
a second control action means for sensing the rate at which said buffer is filling with data, and in response to said rate exceeding a predetermined limit, said second control action means being operable for effecting stopping of the feed of additional documents by said document feed means even though said first threshold may not have been met.

6 more elements

A system for capturing video image data from documents comprising

document feed means for feeding successive documents from a hopper to a document transport,
document transport means for receiving each successively fed document and advancing the respective documents past a document scanner,
document scanner means for scanning the successively transports documents and for generating therefrom video image data, the quantity of which may vary widely depending upon the amount of information present on the document,
a buffer for receiving and temporarily storing video image data,
data input means for directing video image data obtained from said document scanner means into said buffer,
data output means cooperating with said buffer for extracting video image data from the buffer, and
control means cooperating with said buffer and operable to perform a hierarchy of control actions over the flow of video image data into said buffer to assure data integrity and prevent loss of data, said control means including
a first control action means operable in response to the level of stored data in said buffer reaching a first threshold for effecting stopping of the feed of additional documents by said document feed means while allowing documents already in the document transport to continue in process,
a second control action means for sensing the rate at which said buffer is filling with data, and in response to said rate exceeding a predetermined limit, said second control action means being operable for effecting stopping of the feed of additional documents by said document feed means even though said first threshold may not have been met,
an additional control action means operable in response to the level of stored data in said buffer reaching a second threshold lower than said first threshold for effecting resuming of the feed of documents by said document feed means;
and
an additional control action means operable in response to the level of stored data in said buffer reaching a third threshold higher than said first threshold for effecting immediate stopping of the transport of documents by said document transport means so as to thereby immediately stop the flow of additional data to said buffer to thus prevent overflow and loss of data.

9 more elements

A system for capturing video image data from documents comprising

document feed means for feeding successive documents from a hopper to a document transport,
document transport means for receiving a plurality of documents from said documents feed means and for advancing each successive document past a document scanner,
document scanner means for scanning the successively transported documents and for generating therefrom video image data, the quantity of which may vay widely depending upon the amount of information present on the document,
video image data processing and compression means for receiving the video image data from said document scanner means and for processing and compressing the video image data, the quantity of the video image data emanating from said processing and compression means also varying widely depending upon the nature and quantity of the video image data which is received,
a buffer for receiving and temporarily storing video image data,
data input means for directing processed and compressed video iamge data from said data processing and compression means and into said buffer,
data output means cooperating with said buffer for extracting video image data from the buffer, and
control means cooperating with said buffer and operable to perform a hierarchy of control actions over the flow of video image data into said buffer to assure data integrity and prevent loss of data, said control means including
a first control action means operable in response to the level of stored data in said buffer reaching a first threshold for effecting stopping of the feed of additional documents by said document feed means while allowing documents already in the document transport to continue in process, and
a second control action means for sensing the rate at which said buffer is filling with data, and in response to said rate exceeding a predetermined limit, said second control action means being operable for effecting stopping of the feed of additional documents by said document feed means even though said first threshold may have been met.

7 more elements

A method for capturing video image data from documents comprising

feeding successive documents from a hopper to a document transport,
transporting each successive document past a document scanner and optically scanning the successively transported documents and generating therefrom video image data, the quantity of which may vary widely depending upon the amount of information present on the document,
receiving and temporarily storing the video image data obtained by the document scanner in a buffer,
extracting video image data from the buffer to a data output device, and
performing a hierarchy of control actions over the flow of video image data into the buffer to assure data integrity and prevent loss of data, including
(i) in response to the level of stored data in said buffer reaching a first threshold, effecting stopping of the feed of additional documents by said document feed means while allowing documents already in the document transport to continue in process, and
(ii) sensing the rate at which said buffer is filling with data, and in response to said rate exceeding a predetermined limit, effecting stopping of the feed of additional documents by said document feed means even though said first threshold may not have been met.

4 more elements

Dependencies are inferred from the claim text.

System for scanning documents without loss of image data

Life of this patent

System for scanning documents without loss of image data

Life of this patent

Abstract

Claims10