Library circulation control system - Patent Review 4141078

What is claimed is:

1. An automated library circulation and security control system for enabling only authorized users of library materials to independently charge items of said library materials to their accounts and to independently remove the charged items from the library, each item of said materials having identifying indicia thereon and a status-indicating element attached thereto alterable between multiple states to represent the circulation status of said item, comprising:

card reading means actuable by said user including means for reading user indicia on a card presented by an authorized user, and means for generating a first signal representative of said user indicia;

code reading means actuable by said user including a housing having a support for maintaining said one library item stationary, scanning means mounted in said housing near said support for reading said indicia on said item of library materials identifying said item, and means for generating a second signal representative of said item;

data processing means in electrical communication with said card reading means and said code reading means, including a memory for storing electronic records having data files representative of said authorized users and of the library items authorized to be charged by said authorized users, including means for comparing said first and second signals with said data files, means for generating an enabling signal in response to said first and second signals corresponding to an authorized user and authorized item in said data files and means for storing said first and second signals in said stored records to charge said item to said user;

security means adjacent said support and responsive to said enabling signal from said data processing means for changing the state of said status-indicating element attached to said library item as said item rests on said support to change the circulation status of said item;

detection means near an exit of said library for sensing the status-indicating element of said library item as it is removed from the library to determine the circulation status of said item; and

alarm means in electrical communication with said detection means for generating a signal in response to a sensed circulation status for which removal of said item is not authorized.

2. The system of claim 1 wherein said card reading means comprises an optical reader having a slot for insertion of said card and optical sensors adjacent said slot to read said card indicia.

3. The system of claim 1 wherein said scanning means comprises optical scanning means mounted in said housing above said support to read said visual indicia on said library item.

4. The system of claim 1 wherein said data processing means comprises a digital electronic computer having first memory means for storing user data representative of said authorized users, second memory means for storing item data representative of said authorized items, processing means for comparing said first signal to said user data and for comparing said second signal to said item data, and control means for generating said enabling signal in response to said first signal corresponding to said user data and said second signal corresponding to said item data.

5. The system of claim 1 wherein said status-indicating element is a magnetic element attached to said library item, and wherein said security means comprises electromagnetic means actuable by said data processing means for magnetizing and demagnetizing said magnetic element.

6. The system of claim 5 wherein said detection means comprises means for generating an electromagnetic field in an exit path from the library to sense the status of said magnetic element attached to said item as it is removed from the library.

7. The system of claim 1 and further characterized by keyboard means in electronic communication with said data processing means for modifying the data records stored by said data processing means representative of authorized users and authorized items to be charged by the authorized users.

8. A book processor station for use in a library circulation and security control system utilizing a computer and an actuable alarm unit for detecting the circulation status of library books, said system enabling an authorized user to independently conduct transactions without librarian assistance and to independently modify the circulation status of library books, each book having indicia to identify the book and multiple-state means representative of the circulation status of the book having at least one state which will actuate said actuable alarm unit, comprising:

housing means including means for supporting a book in a stationary position and means for signaling the computer that the book is in position for processing;

card reader means mounted in said housing means actuable by said user, including means for accepting a user card having indicia identifying said user and means for generating a first signal representative of said card indicia;

code reader means mounted in said housing means adjacent said supporting means, including means for sensing said identifying indicia on the stationary book and means for generating a second signal representative of said book indicia;

communication means, including means for transmitting said first and second signals to said computer for comparison with data signals stored in said computer, and means for receiving an enabling signal from said computer generated in response to said comparison; and

means mounted in said housing means adjacent said supporting means and actuable by said enabling signal for changing the state of said multiple-state means as the book is placed adjacent thereto to a state which will not actuate said alarm unit for detecting circulation status of the book.

9. The book processor station of claim 8 wherein said housing means comprises an enclosure for supporting said book, sensing means associated with said enclosure for detecting the presence of an item other than said book in said enclosure, and means for generating and transmitting to said computer a signal responsive to said sensing means.

10. The book processor station of claim 8 wherein said code reader comprises an optical scanner pivotally supported in said housing means in a fixed position above said supporting means to scan said book indicia.

11. The station of claim 8 wherein said card reader comprises an optical reader having a slot for inserting said card, optical sensing means for reading said indicia on said card and means for generating said first signal representative of said card indicia.

12. The station of claim 8 and further comprising keyboard entry means for generating data signals to be sent by said transmitting means to said computer.

13. The book processor station of claim 8 and further comprising display means for receiving data signals from said computer by said receiving means and for visually displaying information for said user representative of said data signals.

14. The book processing station of claim 8 and further comprising printing means for receiving data signals from said computer by said receiving means and for visually printing information for said user representative of said data signals.

15. The book processing station of claim 8 wherein said multiple-state means comprises a magnetic strip attached to the book and wherein said means for changing the state of said multiple-state means comprises actuable electromagnetic means adjacent said supporting means for magnetizing and demagnetizing said magnetic strip attached to the book.

16. The book processing station of claim 8 wherein said station is remote from said computer and wherein said transmitting and receiving means comprise electrical cables connecting said station and said computer.

17. In an automated real-time library system having a computer for controlling the circulation of a plurality of library items and for limiting access to said library items to only predetermined authorized users and for only predetermined authorized items by comparing data signals representative of said items and users to data files stored in memory of said computer and by transmitting a control signal in response to said items and users being authorized, each item having a status-indicating element alterable between multiple states to represent the circulation status of said item, a processor for changing the state of said element to alter the circulation status of said library item, comprising:

means for generating a first data signal representative of a library item and means for generating a second data signal representative of a library user for transmission to said computer;

support means in said processor including a receptacle having a first portion in which said authorized library item is supported in a stationary position and a second portion in which said library item tends to move toward said first portion of said receptacle;

means in said receptacle for securing only one of said library items in said second portion of said receptacle;

means associated with said support means for altering the status-indicating element of said library item in said second portion in response to said control signal generated by said computer after receiving said first and second data signals;

first sensing means for said receptacle for sensing the presence of an object in the first portion of said receptacle and thereby generating a first alarm signal;

second sensing means about the periphery of said receptacle for sensing an object across said periphery and thereby generating a second alarm signal; and

means in communication with said first and second sensing means for generating a disable signal to disable said altering means in response to either said first alarm signal or said second alarm signal.

18. The processor of claim 17 wherein said support means comprises a tray having a bottom surface inclined at an angle to the horizontal for said library item to slide by gravity toward the lower part of said tray, and wherein said altering means is positioned adjacent the upper part of said tray.

19. The processor of claim 18 wherein said securing means comprises means on the bottom surface of said tray in said upper part for holding said library item stationary in said upper part of the tray.

20. The processor of claim 17 wherein said first sensing means in said receptacle comprises a photocell in communication with a light source across the lower part of the tray.

21. The processor of claim 17 wherein said second sensing means comprises a plurality of photocell units around the periphery of said receptacle in communication with light sources in said support means above the periphery of the receptacle.

22. The processor of claim 17 wherein said status-indicating element comprises a magnetic strip on said library item and wherein said altering means comprises electromagnetic coil means for magnetizing and demagnetizing said magnetic strip.

23. An automated system for recording and controlling inventory transactions by enabling patrons authorized for access to inventory materials to independently charge items of said materials to their accounts and to independently remove the charged items from the inventory, each item of said materials having thereon inventory indicia and a status-indicating element alterable between multiple state to represent a control status of said item detectible by a sensing device, comprising:

means actuable by said patron for identifying said patron, including means for interpreting patron indicia presented by said patron, and means for generating a first signal representative of said patron indicia;

code reading means responsive to said identifying means, including a housing having a support for maintaining said one inventory item stationary, scanning means mounted in said housing near said support for reading said inventory indicia on said item of inventory materials identifying said item, and means for generating a second signal representative of said item;

data processing means in communication with said identification means and said code reading means, including a memory for storing electronic records having data files representative of said authorized patrons and of the inventory items authorized to be charged by said authorized patrons, including means for comparing said first and second signals with said data files, means for generating an enabling signal in response to said first and second signals corresponding to an authorized patron and an authorized item, respectively, in said data files and means for storing said first and second signals in said stored records to charge said item to said patron; and

security means adjacent said support responsive to said enabling signal from said data processing means for changing the state of said statusindicating element on said inventory item as said item rests on said support to change the control status of said item so that said item may be removed from inventory without detection by said sensing device.

24. The system of claim 23 wherein said identifying means comprises card reader means for reading patron indicia on a card presented by the patron to the card reader.

25. The system of claim 23 wherein said code reading comprises an optical scanning means for reading said inventory indicia.

26. The system of claim 23 wherein said status-indicating element comprises a magnetic element on each item having magnetized and demagnetized states and wherein said security means comprises electromagnetic means for changing said magnetic element between said magnetized and demagnetized states.

27. The system of claim 26 wherein said sensing device comprises means for generating a magnetic field in an exit path from said inventory to sense the state of said magnetic element of said item as it is removed from inventory.

28. A method of using a book processor station in a library circulation and security control system utilizing a computer and an actuable alarm unit for detecting the circulation status of library books, said system enabling an authorized user to independently conduct transactions without librarian assistance and to independently modify the circulation status of library books each book having indicia to identify the book and multiple-state means representative of the circulation status of the book having at least one state which will actuate said actuable alarm, comprising:

supporting a book in a stationary position on a housing and generating a signal to the computer that the book is in position for processing;

actuating a card reader mounted in said housing to accept a user card having indicia identifying said user and to generate a first signal representative of said card indicia;

actuating a code reader mounted in said housing to sense said identifying indicia on the stationary book and means for generating a second signal representative of said book indicia;

transmitting said first and second signals to said computer for comparison with data signals stored in said computer, and receiving an enabling signal from said computer generated in response to said comparison; and

changing the state of said multiple-state means as the book is supported on the housing to a state which will not actuate said alarm unit for detecting circulation status of the book.

29. A method of using a processor in an automated real-time library system having a computer for controlling the circulation of a plurality of library items and for limiting access to said library items to only predetermined authorized users and for only predetermined authorized items, each item having a status-indicating element alterable between multiple states to represent the circulation status of said item, said processor being adapted to change the state of said element to alter the circulation status of said library item, comprising:

generating a first data signal identifying an authorized item and a second data signal identifying an authorized user of said item for transmission to said computer;

supporting said library item in said processor in a receptacle having a first portion in which said authorized library item is supported in a stationary position and a second portion in which said library item tends to move toward said first portion of said receptacle;

securing only one of said library items in said second portion of said receptacle;

altering the status-indicating element of said library item in said second portion in response to a control signal generated by said computer after receiving said first and second data signals;

sensing the presence of an object in the first portion of said receptacle and thereby generating a first alarm signal;

sensing an object across the periphery of said receptacle and thereby generating a second alarm signal; and

generating a disable signal to disable said altering means in response to either said first alarm signal or said second alarm signal.

30. A method of using an automated system having a computer for recording and controlling inventory transactions to enable patrons authorized for access to inventory materials to independently charge items of said materials to their accounts and to independently remove the charged items from the inventory, each item of said materials having thereon inventory indicia and a status-indicating element alterable between multiple states to represent the control status of said item, comprising:

identifying said patron, including interpreting patron indicia presented by said patron, and generating a first data signal representative of said patron indicia;

positioning said item stationary on a support having a scanning device capable of reading said inventory indicia;

reading said inventory indicia on said item of inventory materials identifying said item using said scanning device in said support, and generating a second data signal representative of said item;

comparing said first and second data signals with data files stored in memory of said computer having data representative of said authorized patrons and of the inventory items authorized to be charged by said authorized patrons;

generating an enabling signal in response to said first and second data signals corresponding to an authorized patron and an authorized item, respectively, in said data files;

storing said first and second data signals in said stored records to charge said item to said patron;

changing the state of said status-indicating element on said inventory item with said item positioned on said support in response to said enabling signal to change the control status of said item;

sensing the status-indicating element of said item of inventory materials as it is removed from inventory to determine the control status of said item; and

generating an alarm signal in response to a sensed control status for which removal of said item is not authorized.

Description Submit all comments and votes

BACKGROUND OF THE INVENTION

This invention relates to a library circulation control system and more particularly to a computer controlled system for processing library transactions and detecting unauthorized removal of library books.

In a conventional library system, books are checked out and otherwise processed manually and circulation records are maintained by manual entries on index cards. This process is slow and cumbersome and typically requires a substantial number of workers to keep the records current. Special functions such as placing books on hold or reserve, preparing lists of overdue books and fines, and taking inventory of the library stock requires additional substantial time and manpower. More sophisticated work such as preparing statistical reports about patrons and circulation are extremely difficult with manual systems. Moreover, additional personnel are required at each library exit to maintain security by checking all outgoing library materials.

Attempts at automating library functions have provided improvements but have lacked simplicity and completeness. The complexity of operating such systems has required that trained library personnel interface with the system input and output devices to insure accuracy. For example, the use of hand held optical readers for inputting patron and book data usually requires a trained operator to properly move the device in order to accurately read the input information. Moreover, prior automated circulation control systems do not include an integrated theft control feature. Systems providing for the detection of unauthorized removal of library items utilize separate units requiring additional steps which must be included with the procedures of a circulation control system.

SUMMARY OF THE INVENTION

The present invention is concerned with an automated library system combining circulation control and theft detection functions in one system. The input and output devices are designed for operation by untrained patrons for several simple functions such as charging out books, and can easily be switched to a different mode by librarians to perform additional more sophisticated tasks. The system utilizes a centralized computer for data processing and storage and remote terminals which can be conveniently located for easy patron use. Access to the terminals by patrons is provided by the presentation of an authorized patron identification card to the termial. The patron then performs the charging and security functions using the terminal without the aid of a librarian. The book is placed in a book tray where an identifying label on the book is read by an optical scanner mounted above the tray. At about the same time, a sensitized magnetic strip in the book binding is demagnetized to allow the book to be taken past magnetic detection devices at the library exits. The tray is structured to accept only one book during the charging and demagnetizing operations. Control of the terminal functions is conducted by the computer which also prepares and stores transaction records and performs other data processing functions. The terminals may be key accessed by librarians to generate, modify and interrogate data files in the computer, to override the automatic patron functions and to test the operability of the system. The transaction records and other data files is periodically communicated by the computer to a central data processor for updating master inventory files.

In accordance with one aspect of the present invention, a library circulation control system is provided for automatically charging library materials to authorized users of the system. Means are provided for generating first and second signals representative of the authorized user and an item of the library materials. Other means process the first and second signals to charge the library item against the user and to change the state of alterable means on the library item to represent a change in the circulation status of the item.

In another aspect of the present invention, a book processor terminal is used in an automatic library system having a computer to conduct transactions modifying the circulation status of library books for authorized users. The book is supported in housing means in a stationary position for processing. A code reader in the housing means adjacent to the supporting means reads indicia on the stationary book to identify the book and generate a first signal representative of the book indicia. A card reader in the housing identifies indicia on a user card inserted therein and generates a second signal representative of the card indicia. Means are provided for transmitting the first and second signals to a computer for processing.

In yet another aspect of the present invention, an automated library circulation control system includes data storage means for storing a set of data representative of library items and authorized users. Data processing means have first and second means for processing a set of data in response to first and second enable signals. Input means provide control data to the data processing means and include a first mode means for generating a first enable signal in response to a user who is authorized to enable only the first processing means. The input means further include a second mode means which generate a second enable signal in response to a user authorized to enable the first and second processing means. Switch means have first and second mode positions to provide mutually exclusinve actuation of the first or the second mode means.

In accordance with yet another aspect of the present invention, a processor for use in a library system controlling the circulation of a plurality of library items includes actuable means for changing an alterable element on each of the library items to modify the circulation status of the item in response to actuating signals from the library system. Support means hold one of the library items in a stationary position for the actuable means to change the alterable element. Detection means are associated with the support means to detect the presence of an object other than the one library item on the support means. A signal is provided to actuate the actuable means only when the detecting means indicates that only one library item is present on the support means.

Another aspect of the present invention, includes a system for controlling the inventory of a plurality of items, each having a first element identifying the item and a second alterable element identifying the inventory status of the item. Means sense the first element to determine its identity. Actuable means are provided to alter the second element to change its inventory status. Other means are responsive to the sensing means to actuate the actuable means.

In accordance with another aspect of the present invention, a label is provided for attaching to a library item. Visual indicia on one side of the label include a plurality of coded bars, each bar being representative of a decimal number to identify the library item. Means on the other side of the label affix the label to the item so that the label is removable from the item only by being damaged so that it cannot be affixed to another library item.

From the foregoing, it is apparent that the present invention provides several advantages over the prior art. The system of the present invention allows a patron to charge out library materials without assistance or supervision by library personnel, resulting in a savings of time and labor. The theft detection unit is an integral part of the circulation control system so that the demagnetization and magnetization of the detection strip in each book is accomplished during charging and discharging of the book without additional effort by the patron or the librarian. The charge out and desensitizing procedures are accomplished quickly and accurately by the use of a housing structure fixing the position of the scanning and activator units with respect to each library item. A further advantage is seen in the use of a mode switch, which allows the librarian to have direct access to the computer data storage in order to build and modify data files, provide special instructions to the computer controller and determine the readiness of each unit in the system. Additional security features are included in the system to maximize control and accuracy and to minimize attempts to "beat the system". The system is designed to generate data compatible with a remote central data processor and to transmit data to and from that processor periodically in order to utilize its greater capabilities. The system is easily expanded to include additional patron book processing stations, increased data storage capacity and different types of input/output devices. The system is particularly adaptable to other real-time applications at remote locations.

DESCRIPTION OF THE DRAWINGS

A more complete understanding of the advantages, structure and operation of the present invention may be had by referring to the following detailed description when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a simplified block diagram showing the basic units of the present invention;

FIG. 2 is a pictorial view of the computer, console and book processor station of the present invention;

FIG. 3 is a partial cutaway front perspective view of the book processor station shown in FIG. 2;

FIG. 4 is a partial cutaway back perspective view of the book processor station shown in FIG. 2;

FIG. 5 is a front view of the book processor station of FIG. 2, showing the control panel, card reader and display unit;

FIG. 6 is a top plan view of a patron identification card used with the card reader shown in FIG. 5;

FIG. 7 is a partially cutaway perspective view of a portion of the book processor station of FIG. 2, showing the book tray and the activate/deactivate unit;

FIG. 8 is a partially cutaway perspective view of a library book shown in the magnetic detector strip and the bar coded label on the book;

FIG. 9 is a partial cutaway perspective view of the book processor station of FIG. 2 showing an optical scanner;

FIGS. 9A and 9B are block diagrams showing the logic interfacing of the components of the book processor station of FIG. 2 with the rest of the system; and

FIGS. 10 through 22 are flow diagrams showing the steps in the operation of the library circulation control system of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A brief overview of the system and its operation will first be given. The system apparatus will then be described in detail followed by a description of the system operation. Referring to FIG. 1, a block diagram of the library circulation control system 10 of the present invention is shown.

The system 10 includes a library terminal 12 consisting of a computer 14 connected to a disc storage unit 16, a paper tape reader 17, a book processor station interface 18 and a central computer communications interface 22. Computer 14 is the controller for the system performing the necessary data processing functions for the system to operate as a library circulation control system. Data files concerning valid users, daily transactions, books on reserve, books on hold and fines paid are stored on disc storage unit 16. Book processor station interface 18 enables the computer 14 to communicate with each book processor station.

A system console 20 is in communication with library terminal 12 and includes a keyboard 24, a printer 26 and a dual cassette recorder 28. Keyboard 24 communicates directly with computer 14 on system startup and shutdown and certain other control functions not performed during normal system operation. Printer 26 logs the current status of the system and prompts the librarian for inputs. The daily transactions are recorded by cassette recorder 28 on a cassette cartridge to provide a backup for the data files stored on disc storage unit 16.

The central computer communications interface 22 permits the transfer of all the data files on the disc storage unit 16 to a central computer at a remote location for updating user records, determination of overdue status, and other operations. This transfer is normally made after closing hours while the book processor stations are not being used. When the central computer completes processing of the data, the files are updated and transferred back to the library terminal after which the book processor stations resume operation utilizing the new data.

The book processor stations interface 18 is connected to a plurality of book processor stations 30 for charging and discharging books and for displaying and modifying the computer data files. Each station 30 includes an identification card reader 32, a display unit 34, a keyboard 36, an optical scanner 38, a book activate/deactivate unit 40, a printer 42 and a control panel 44. A station logic unit 43 interfaces between each of the station components and library terminal 12. Logic unit 43 coordinates the transfer of data, control signals and status signals between the library unit 12 and the components of station 30.

Card reader 32 reads an identification card which provides access for the user or librarian to station 30. The identification card is inserted in card reader 32 and a ten digit number on the card is matched with an authorized number in an appropriate data file before a transaction can be performed at the station.

Display unit 34 provides alphanumeric messages to prompt the user or librarian on the use of book processor station 18. Specific step-by-step instructions are displayed for each function that is performed. Keyboard entries by the operator from keyboard 36 are displayed as entered. Additional messages, such as confirmation of action and file data are displayed as requested.

A bar-coded label on each book representing the book circulation number is read by optical scanner 38. The book is oriented in a book tray at the station with the label facing up and the spine of the book facing the front of the station. Scanner 38 reads a nine digit number on the label and generates signals representing the number which are transferred to computer 14.

Activation and deactivation of a magnetic strip in a book is performed by the activate/deactivate unit 40 located under the book tray. The strip located in the spine of each book is demagnetized when the book is charged or checked out and magnetized when the book is discharged or returned. Deactivation of the strip occurs on command from computer 14 after it is determined that the user is permitted to charge the book. Failure of the user to deactivate the strip before taking the book from the library will initiate an alarm at the library exit.

Date due and book-on-hold confirmation messages are printed out by printer 42 for the user. Included in the date due message is the user's identification number, the book number, the date charged, and the date due. If a book has been placed on hold, the hold print-out includes the user identification number, the book number, and the date that the hold request was entered.

Control Panel 44 provides for selection of librarian or user operation modes using a keylock switch. Other functions which may be selected in the librarian mode include a switch for manual or automatic operation and a switch for manually charging or discharging a book. Another switch provides a manual eject for the identification card. Status information displayed on the control panel in the librarian mode indicates that the ID card is in place, the book is in place, the book is activated, the book is deactivated, there is gate interference, two books are presented, and the printer is out of paper.

To charge a book a patron inserts his identification card in card reader 32 to be automatically read and checked against a patron file containing the numbers of all valid library patrons. If the patron's number is not found in the file, the transaction will not proceed and the alphanumeric display unit 34 advises the patron to consult the librarian in order to charge out the book. The patron is also prevented from charging out any books if his record indicates that he has maximum number of books on loan, has overdue books, or has had library privileges suspended. In any of these cases, the librarian has the capability to override the transaction if desired.

Assuming that the patron's identification is accepted, the patron then inserts the book in the book tray with the spine next to the activator/deactivator unit 40 and the bar code label facing up. The book circulation number is read by optical scanner 38 and checked against the list of books in the hold data file on disc storage unit 16. If the circulation number is found in the hold file, the computer will check the number of the first requester. If this requester number matches the number on the patron identification card currently in the machine the requester number is removed from the hold file which is updated and rewritten on disc storage unit 16. Otherwise, the patron is advised by the display to consult the librarian. If the circulation number is not found in the hold file the computer is authorized to proceed. To deactivate the detection strip in the book, the library control terminal 12 sends a signal to activator/deactivator unit 40 which then desensitizes the detection strip in the book. If the patron attempts to insert two or more books simultaneously in the book tray, the top books will slide out of position since the book tray is sloped. The bottom book is held in place by a rough surface with a high coefficient of friction. The tray includes a number of photoelectric devices around its periphery so the additional books cannot be held in place by the patron.

After the book strip is deactivated a date due slip is printed by printer 42. The loan period previously entered into the system by the librarian is used to calculate the date due for the patron unless the hold record shows more than two requester numbers or the circulation number is found in a reserve file. In these cases the date due is a shorter loan period. A transaction record is entered in disc storage unit 16 and cassette recorder 28 after each transaction is completed. Each record includes a charge code, patron number, date due, and circulation number.

The detection strips of returned books are reactivated by the librarian inserting a special card in reader 32 and then properly placing the book in the book tray. The bar-coded label is read and the book detection strip is reactivated. The check-in or discharge transaction is entered on disc storage unit 16 and cassette recorder 28 and includes a discharge code, book number, date and time.

A patron can also use his identification card to place a book on hold. After inserting the card in card reader 32, the patron depresses the "HOLD" key, types in the book number on station keyboard 36 and confirms the number by observing the output of display unit 34. If the number is valid, the entry of the data is recorded in the hold file.

The library staff is able to perform a number of additional functions by turning a key-locked switch on control panel 44 to the "Librarian" position. In this position, the librarian types in a four digit alphanumeric code on keyboard 36 indicating the function to be performed. The library control terminal 12 responds by displaying sequential instructions on display unit 34. The librarian responds with appropriate inputs on the alphanumeric keyboard 36, such as by entering a patron code or a book number. The patron is locked out of this mode since a key is required to operate the mode switch.

In the librarian mode, the library staff is able to remove a requester from the hold file by typing in a code, the requester's card number, and the book number. The librarian can also add books to the reserve file by typing in a code, the book number and the number of days or hours of the loan period. In a similar fashion the librarian can remove books from the reserve file by entering the reserve code and the book number. Other functions which can be performed in the librarian mode include adding or deleting a number in the patron file, overriding the charge and discharge operations, displaying the contents of the reserve file, displaying or entering the time of day and writing the time record file, interrogating the transaction file by circulation number, and entering the date due. In addition, by using a telephone link the librarian can transfer data files to and from a remote central computer using system console 20.

Referring now to FIG. 2, a perspective view of library circulation control system 10 is shown. Although library terminal 12, system console 20 and book processor station 30 are shown grouped together, it is understood that each unit may be located remote from the others with interconnecting communication links.

Library terminal 12 includes computer 14, disc storage unit 16, paper tape reader 17, book processor stations interface 18 and central computer communications interface 22. Each unit of ter