Information retrieval and display systems

• US 6,314,426 B1
• Filed: 04/05/1999
• Issued: 11/06/2001
• Est. Priority Date: 11/07/1995
• Status: Expired due to Fees

• Current Assignee: Roundpoint, Inc.
• Original Assignee: Roundpoint, Inc.
• Inventors: Cox, Paul Nicholas, Martin, Sean Christopher
• Primary Examiner(s): Choules, Jack
• Assistant Examiner(s): LEWIS, CHERYL RENEA
• Application Number:
  US09/068,440
• Time in Patent Office: 946 Days
• Field of Search: 707/100, 707/102, 345/156, 345/161, 345/163, 345/167, 345/341, 345/352, 345/353, 345/354, 345/123, 345/145
• US Class Current: 1/1
• CPC Class Codes: G05G 9/047 the controlling member being movable by hand about orthogonal axes, e.g. joysticks for switches H01H25/04
• CPC Class Codes: G06F 16/34 Browsing; Visualisation therefor
• CPC Class Codes: G06F 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors
• CPC Class Codes: G06F 3/03543 Mice or pucks G06F3/03541 takes precedence
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/0485 Scrolling or panning
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

In an information retrieval and display system, an interface unit receives signals from a hand-held control unit and controls the information displayed on a display. The information available for display is arranged in a tree structure. The interface unit is arranged to scroll through the currently displayed information in a first direction at a speed related to the displacement of the control unit in a first direction, to scroll through the currently displayed information in a second direction at a speed related to the displacement of the control unit in a second direction, to display information from a lower level in the tree in response to movement of the control unit in a third direction, and to display information from a higher level in the tree in response to movement of the control unit in a fourth direction.

Claims

1. Information retrieval and output apparatus for retrieving and outputting information from storage means, comprising:

information retrieval means for retrieving information from the storage means;

output means for outputting to a user information retrieved from the storage means; and

selecting means for selecting information for output in units by the output means in accordance with links between the units of information, said selecting means comprising a user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions and control means for controlling the information output by the output means in response to the control signals, wherein said user input means comprises a control member having first and second degrees of freedom and movable or actuable in first and second directions in each of said degrees of freedom, said first and second control signals being produced in response to movement or actuation in first and second directions respectively in said first degree of freedom with an extent of movement or actuation defining a value of the control signal for determining the speed of scrolling, and said third and fourth control signals being produced in response to movement or actuation in first and second directions respectively in the second degree of freedom, wherein said first and second degrees of freedom are movements or actuations along first and second orthogonal lines;

and wherein;

the control means is arranged so that;

in response to the first control signal, information from a current unit being output by the output means is scrolled through in a first direction at a speed related to the value of the control signal set by the first operator action;

in response to the second control signal, information from the current unit being output by the output means is scrolled through in a second direction, opposite to the first direction, at a speed related to the value of the control signal set by the second operator action;

in response to the third control signal, information from a first further unit defined by a first link from the current unit is output by the output means; and

in response to the fourth control signal, information from a second further unit defined by a second link from the current unit is output by the output means.

2. Apparatus according to claim 1, wherein said control member is a joystick.

3. Apparatus according to claim 1, wherein said control member is a pressure-sensitive member.

4. Information retrieval and output apparatus for retrieving and outputting information from storage means, comprising:

information retrieval means for retrieving information from the storage means;

output means for outputting to a user information retrieved from the storage means; and

selecting means for selecting information for output in units by the output means in accordance with links between the units of information, said selecting means comprising a user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions and control means for controlling the information output by the output means in response to the control signals,

wherein said user input means is a trackerball, said first and second control signals being produced in response to movement of the trackerball in first and second opposite directions respectively with an extent of movement defining a value of the control signal for determining the speed of scrolling, and said third and fourth control signals being produced in response to movement of the trackerball in third and fourth opposite directions respectively,

and wherein the control means is arranged so that;

wherein;

the control means is arranged so that;

in response to the first control signal, information from a current unit being output by the output means is scrolled through in a first direction at a speed related to the value of the control signal set by the first operator action;

in response to the second control signal, information from the current unit being output by the output means is scrolled through in a second direction, opposite to the first direction, at a speed related to the value of the control signal set by the second operator action;

information from a first further unit defined by a first link from the current unit is output by the output means in response to a third said control signal generated by a relatively fast movement of the trackerball in the third direction, but is not output in response to a relatively slow movement of the trackerball in the third direction; and

information from a second further unit defined by a second link from the current unit is output by the output means in response to a fourth said control signal generated by a relatively fast movement of the trackerball in the fourth direction, but is not output in response to a relatively slow movement of the trackerball in the fourth direction.

5. Apparatus according to claim 4, wherein the control means is arranged to automatically re-set a zero-displacement reference position for the third and fourth directions after a relatively fast movement of the trackerball in the third direction or the fourth direction.

6. Information retrieval and output apparatus for retrieving and outputting information from storage means, comprising:

information retrieval means for retrieving information from the storage means;

output means for outputting to a user information retrieved from the storage means; and

selecting means for selecting information for output in units by the output means in accordance with links between the units of information, said selecting means comprising a user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions and control means for controlling the information output by the output means in response to the control signals,

wherein said user input means is a mouse, said first and second control signals being produced in response to movement of the mouse in first and second opposite directions respectively, with an extent of movement defining a value of the control signal for determining the speed of scrolling, and said third and fourth control signals being produced in response to movement of the mouse in third and fourth opposite directions respectively,

and wherein;

the control means is arranged so that;

in response to the first control signal, information from a current unit being output by the output means is scrolled through in a first direction at a speed related to the value of the control signal set by the first operator action;

in response to the second control signal, information from the current unit being output by the output means is scrolled through in a second direction, opposite to the first direction, at a speed related to the value of the control signal set by the second operator action;

in response to the third control signal, information from a first further unit defined by a first link from the current unit is output by the output means;

in response to the fourth control signal, information from a second further unit defined by a second link from the current unit is output by the output means;

but

the information being output is not changed in response to movement of the mouse less than a predefined distance in any of the first, second, third and fourth directions.

7. Apparatus according to claim 6, further comprising means to display on display means a graphic indicating to the user a current position of the mouse in the first, second, third and fourth directions and the predefined distance in each direction.

8. Information retrieval and output apparatus for retrieving and outputting information from storage means, comprising:

information retrieval means for retrieving information from the storage means;

output means for outputting to a user information retrieved from the storage means; and

selecting means for selecting information for output in units by the output means in accordance with links between the units of information, said selecting means comprising a user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions and control means for controlling the information output by the output means in response to the control signals,

wherein said user input means is a wand, said first and second control signals being produced in response to angular displacement of the wand in first and second opposite directions respectively with an extent of angular displacement defining a value of the control signal for determining the speed of scrolling, and said third and fourth control signals being produced in response to angular displacement of the wand in third and fourth opposite directions respectively;

and wherein;

the control means is arranged so that;

in response to the first control signal, information from a current unit being output by the output means is scrolled through in a first direction at a speed related to the value of the control signal set by the first operator action;

in response to the second control signal, information from the current unit being output by the output means is scrolled through in a second direction, opposite to the first direction, at a speed related to the value of the control signal set by the second operator action;

in response to the third control signal, information from a first further unit defined by a first link from the current unit is output by the output means; and

in response to the fourth control signal, information from a second further unit defined by a second link from the current unit is output by the output means.

9. Apparatus according to claim 9, further comprising means for enabling a user to set a zero-displacement position for the first and second directions and for the third and fourth directions.

10. Information retrieval and output apparatus for retrieving and outputting information from storage means, comprising:

information retrieval means for retrieving information from the storage means;

output means for outputting to a user information retrieved from the storage means; and

selecting means for selecting information for output in units by the output means in accordance with links between the units of information, said selecting means comprising a user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions and control means for controlling the information output by the output means in response to the control signals,

wherein said user input means comprises four control elements, each actuable manually for different durations to cause the user input means to produce a respective different one of the control signals, the respective duration of actuation of each element for producing the first and second control signals generating a value of the respective first and second control signals for determining the speed of scrolling;

wherein;

the control means is arranged so that;

in response to the first control signal, information from a current unit being output by the output means is scrolled through in a first direction at a speed related to the value of the first control signal set by the first operator action;

in response to the second control signal, information from the current unit being output by the output means is scrolled through in a second direction, opposite to the first direction, at a speed related to the value of the second control signal set by the second operator action;

in response to the third control signal, information from a first further unit defined by a first link from the current unit is output by the output means; and

in response to the fourth control signal, information from a second further unit defined by a second link from the current unit is output by the output means.

11. Apparatus according to claim 10, wherein the four control elements comprise first and second rocker switches.

12. Information retrieval and output apparatus for retrieving and outputting information from storage means, comprising:

information retrieval means for retrieving information from the storage means;

output means for outputting to a user information retrieved from the storage means; and

selecting means for selecting information for output in units by the output means in accordance with links between the units of information, said selecting means comprising a user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions and control means for controlling the information output by the output means in response to the control signals,

wherein said first operator action is an opposite action to said second operator action, and said third operator action is an opposite action to said fourth operator action;

and wherein;

the control means is arranged so that;

in response to the first control signal, information from a current unit being output by the output means is scrolled through in a first direction at a speed related to a value set by the first operator action;

in response to the second control signal, information from the current unit being output by the output means is scrolled through in a second direction, opposite to the first direction, at a speed related to a value set by the second operator action;

in response to the third control signal, information from a first further unit defined by a first link from the current unit is output by the output means; and

in response to the fourth control signal, information from a second further unit defined by a second link from the current unit is output by the output means.

13. Information retrieval and output apparatus for retrieving and outputting moving image data from storage means, comprising:

information retrieval means for retrieving moving image data from the storage means;

a display for displaying to a user moving images retrieved from the storage means, and selecting means for selecting information comprising moving image data for display in units on the display in accordance with links between the units of information, said selecting means comprising a user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions and control means for controlling the information displayed on the display in response to the control signals,

wherein the control means is arranged so that;

in response to the first control signal, the image sequence currently displayed on the display is forwarded at a speed related to a value set by the first operator action;

in response to the second control signal, the sequence currently displayed on the display is rewound at a speed related to a value set by the second operator action; and

in response to the third control signal, a sequence of moving images from a first further unit defined by a first link from the current unit is displayed; and

in response to the fourth control signal, a sequence of moving images from a second further unit defined by a second link from the current unit is displayed.

14. Information retrieval and output apparatus for retrieving and outputting information from storage means, comprising:

information retrieval means for retrieving information from the storage means;

memory for storing information retrieved from the storage means;

a display for displaying to a user information retrieved from the storage means; and

selecting means for selecting information in units for display on the display in accordance with links between the units of information, said selecting means comprising a user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions and control means for controlling the information displayed in response to the control signals,

wherein the units of information are defined as parent and child units, and wherein said selecting means is operative when information from at least one parent unit of information is being displayed on the display to cause downloading from the storage means to the memory of information from the child units of the parent unit so that the information from a child unit is available for display substantially immediately in response to a said third control signal;

and wherein the control means is arranged so that;

in response to the first control signal, information from a current unit being displayed is scrolled through in a first direction at a speed related to a value set by the first operator action;

in response to the second control signal, information from the current unit being displayed is scrolled through in a second direction, opposite to the first direction, at a speed related to a value set by the second operator action;

in response to the third control signal, information from a first further unit defined by a first link from the current unit is displayed substantially immediately by reading the information stored in the memory; and

in response to the fourth control signal, information from a second further unit defined by a second link from the current unit is displayed.

15. Information retrieval and output apparatus for retrieving and outputting information from storage means, comprising:

information retrieval means for retrieving information from the storage means;

output means for outputting to a user information retrieved from the storage means;

selecting means for selecting information for output in units by the output means in accordance with links between the units of information, said selecting means comprising a user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions and control means for controlling the information output by the output means in response to the control signals; and

means for compiling information on the types of information of interest to the user based on information output to the user via the output means;

wherein;

the control means is arranged so that;

in response to the first control signal, information from a current unit being output by the output means is scrolled through in a first direction at a speed related to a value set by the first operator action;

in response to the second control signal, information from the current unit being output by the output means is scrolled through in a second direction, opposite to the first direction, at a speed related to a value set by the second operator action;

in response to the third control signal, information from a first further unit defined by a first link from the current unit is output by the output means; and

in response to the fourth control signal, information from a second further unit defined by a second link from the current unit is output by the output means.

16. Information retrieval and output apparatus for retrieving and outputting audio data from storage means, comprising:

information retrieval means for retrieving audio data from the storage means;

output means for outputting to a user audio data retrieved from the storage means; and

selecting means for selecting audio data for output in units by the output means in accordance with links between the units of audio data, said selecting means comprising a user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions and control means for controlling the audio data output by the output means in response to the control signals,

wherein the control means is arranged so that;

in response to the first control signal the audio sequence currently being output is forwarded at a speed related to a value set by the first operator action;

in response to the second control signal the audio sequence currently being output is rewound at a speed related to a value set by the second operator action;

in response to the third control signal, audio data from a first further unit defined by a first link from the current unit is output by the output means; and

in response to the fourth control signal, audio data from a second further unit defined by a second link from the current unit is output by the output means.

17. Information retrieval and display apparatus, comprising:

data storage means comprising a plurality of data storage blocks each containing a respective different type of information, each type of information including information in a plurality of different categories within said type and each category comprising a plurality of different items of information within said category;

selecting and display means for selecting information from said data storage means and displaying said information in at least three levels of detail, a first of which is a relatively high level in which at least the categories of information within a selected information type are displayed, a second of which is an intermediate level in which an indication of contents of the different items within a selected category are displayed, and a third of which is a relatively low level in which a selected item is displayed; and

control means operable to produce first, second, third and fourth command signals in response to respective first, second, third and fourth operator single actions for controlling said information selecting and display means;

said first and second signals causing scrolling in respective opposite directions through currently displayed information at a speed related to a value set by the operator action;

said third signal causing selection and display of information in a higher level of detail; and

said fourth signal causing display of information in a lower level of detail.

18. Information retrieval and display apparatus comprising:

data storage means comprising a plurality of data storage blocks each containing a respective different type of information, each block comprising a first file containing a plurality of items, of relatively high level information each identifying a respective different category within the information type contained in the data storage block, a plurality of second files each associated with a respective different one of said categories and containing a plurality of items of medium level information each indicating a nature of a respective different one of a plurality of items of relatively low level information within the respective category, and a plurality of third files each associated with a respective different one of said items of medium level information and containing said relatively low level information corresponding to the respective medium level information;

selecting and display means for selecting and displaying information from said files of said data storage means; and

control means operable to produce first, second, third and fourth command signals in response to respective first, second, third and fourth operator single actions;

said first and second signals being arranged to cause scrolling of displayed information in respective first and second directions through a currently selected one of said second files at a speed related to a value set by the operator action for selection of said items of medium level information;

said third signal being arranged to cause said selecting and display means to switch to displaying information from a first file with which said currently selected second file is associated; and

said fourth signal being arranged to cause said selecting and display means to switch to displaying information from a third file with which the currently selected item of medium level information is associated.

19. Apparatus according to claim 18, wherein said storage means includes a plurality of further files associated with at least one of said third files and containing higher level information than the information in said at least one third file and said at least one third file contains information items indicating contents of said plurality of further files, selection of said further files being permitted by causing said control means to generate a said fourth signal when information from said at least one third file is displayed.

20. Information retrieval and output apparatus for retrieving and outputting information from storage means, comprising:

information retrieval means for retrieving information from the storage means;

output means for outputting to a user information retrieved from the storage means; and

selecting means for selecting information for output in units by the output means in accordance with links between the units of information, said selecting means comprising user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions and control means for controlling the information output by the output means in response to the control signals;

wherein;

the control means is arranged so that;

in response to the first control signal, information from a current unit being output by the output means is scrolled through in a first direction at a speed related to a value set by the first operator action;

in response to the second control signal, information from the current unit being output by the output means is scrolled through in a second direction, opposite to the first direction, at a speed related to a value set by the second operator action;

in response to the third control signal, information from a first further unit defined by a first link from the current unit is output by the output means; and

in response to the fourth control signal, information from a second further unit defined by a second link from the current unit is output by the output means.

21. Apparatus according to claim 20, wherein the units of information are defined as parents and children.

22. Apparatus according to claim 21, wherein the first further unit is a child unit of the current unit.

23. Apparatus according to claim 22, wherein the second further unit is a parent unit of the current unit.

24. Apparatus according to claim 23, wherein the second further unit is a unit which was displayed immediately previously to the current unit.

25. Apparatus according to claim 20, wherein the units of information are defined as parents, children and siblings.

26. Apparatus according to claim 25, wherein the second further unit is a sibling unit of the current unit.

27. Apparatus according to claim 26, wherein the first further unit is a sibling unit of the current unit.

28. Apparatus according to claim 20, wherein the information comprises information within a document.

29. Apparatus according to claim 20, wherein one unit of information comprises file information, and information in the first further unit thereof comprises information within a document in a file.

30. Apparatus according to claim 23, wherein the output means comprises display means for displaying information retrieved from the storage means.

31. Information retrieval and output apparatus for retrieving and outputting information from storage means, comprising:

information retrieval means for retrieving information from said storage means;

output means for outputting to a user information retrieved from the storage means; and

selecting means for selecting information for output in units by the output means in accordance with links between the units of information, said selecting means comprising user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator actions and control means for controlling the information output by the output means in response to the control signals, wherein;

the user input means comprises a selecting device having first and second degrees of freedom and being operable to produce first and second control signals in response to an operator action consisting of user movement or actuation of the selecting device in the first degree of freedom, and being operable to produce third and fourth control signals in response to an operator action consisting of user movement or actuation of the selecting device in the second degree of freedom; and

the control means is arranged so that;

in response to the first control signal, information from a current unit being output by the output means is scrolled through in a first direction at a speed related to a value set by the movement or actuation of the selecting device;

in response to the second control signal, information from the current unit being output by the output means is scrolled through in a second direction, opposite to the first direction, at a speed related to a value set by the movement or actuation of the selecting device;

in response to the third control signal, information from a first further unit defined by a first link from the current unit is output by the output means; and

in response to the fourth control signal, information from a second further unit defined by a second link from the current unit is output by the output means.

32. In a system comprising storage means storing information for output to a user, output means for outputting information retrieved from the storage means, and selecting means for selecting information for output in units by the output means in accordance with links between the units of information, said selecting means comprising user input means for generating control signals and control means for controlling the information output by the output means in response to the control signals, a method of outputting information, comprising:

generating a first control signal in response to a first operator single action, and in response thereto scrolling through information from a current unit being output by the output means in a first direction at a speed related to a value set by the first operator action;

generating a second control signal in response to a second operator single action, and in response thereto scrolling through information from the current unit being output by the output means in a second direction, opposite to the first direction, at a speed related to a value set by the second operator action;

generating a third control signal in response to a third operator single action, and in response thereto outputting via the output means information from a first further unit defined by a first link from the current unit; and

generating a fourth control signal in response to a fourth operator single action, and in response thereto outputting via the output means information from a second further unit defined by a second link from the current unit.

33. Control means for use in an information retrieval and output system, which system comprises storage means storing information for output to a user, output means for outputting information retrieved from the storage means, and user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions, said control means comprising means for receiving the control signals and means for generating signals to control the system so as to select information for output in units by the output means in accordance with links between the units of information, such that:

in response to the first control signal, information from a current unit being output by the output means is scrolled through in a first direction at a speed related to a value set by the first operator action;

in response to the second control signal, information from the current unit being output by the output means is scrolled through in a second direction, opposite to the first direction, at a speed related to a value set by the second operator action;

in response to the third control signal, information from a first further unit defined by a first link from the current unit is output by the output means; and

in response to the fourth control signal, information from a second further unit defined by a second link from the current unit is output by the output means.

34. In a system comprising storage means storing information for output to a user, output means for outputting information retrieved from the storage means, and selecting means for selecting information for output in units by the output means in accordance with links between the units of information, said selecting means comprising user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions and control means for controlling the information output by the output means in response to the control signals, a method of operating the control means, such that:

in response to the first control signal, information from a current unit being output by the output means is scrolled through in a first direction at a speed related to a value set by the first operator action;

in response to the second control signal, information from the current unit being output by the output means is scrolled through in a second direction, opposite to the first direction, at a speed related to a value set by the second operator action;

in response to the third control signal, information from a first further unit defined by a first link from the current unit is output by the output means; and

in response to the fourth control signal, information from a second further unit defined by a second link from the current unit is output by the output means.

35. A signal carrying instructions for causing a programmable processing apparatus to become configured as a controller for use in an information retrieval and output system comprising storage means storing information for output to a user, output means for outputting information retrieved from the storage means, and user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions, the instructions being arranged to configure the programmable processing apparatus to control the information output by the output means in response to the control signals so as to select information for output in units by the output means in accordance with links between the units of information, such that:

in response to the first control signal, information from a current unit being output by the output means is scrolled through in a first direction at a speed related to a value set by the first operator action;

in response to the second control signal, information from the current unit being output by the output means is scrolled through in a second direction, opposite to the first direction, at a speed related to a value set by the second operator action;

in response to the third control signal, information from a first further unit defined by a first link from the current unit is output by the output means; and

in response to the fourth control signal, information from a second further unit defined by a second link from the current unit is output by the output means.

36. A data storage medium storing instructions for causing a programmable processing apparatus to become configured as a controller for use in an information retrieval and output system comprising storage means storing information for output to a user, output means for outputting information retrieved from the storage means, and user input means for generating first, second, third and fourth respective control signals in response to first, second, third and fourth respective operator single actions, the instructions being arranged to configure the programmable processing apparatus to control the information output by the output means in response to the control signals so as to select information for output in units by the output means in accordance with links between the units of information, such that:

in response to the first control signal, information from a current unit being output by the output means is scrolled through in a first direction at a speed related to a value set by the first operator action;

in response to the second control signal, information from the current unit being output by the output means is scrolled through in a second direction, opposite to the first direction, at a speed related to a value set by the second operator action;

in response to the third control signal, information from a first further unit defined by a first link from the current unit is output by the output means; and

in response to the fourth control signal, information from a second further unit defined by a second link from the current unit is output by the output means.

37. Data processing apparatus for retrieving and outputting information in a plurality of different categories, each category comprising a plurality of different items, comprising:

means for generating a first output identifying said categories for enabling selection of a category in response to a first user command;

first retrieving means responsive to selection of a category by a said first user command;

(a) for generating a second output identifying the different items in the selected category for enabling selection of an item in response to a second user command, and

(b) for retrieving for potential future output the first portion of respective items in the selected category;

second retrieving means responsive to selection of an item by a said second user command;

(a) for generating a third output containing the first portion of the selected item retrieved by the first retrieving means, and

(b) for retrieving for future output the remainder of said selected item.

38. Apparatus in accordance with claim 37, wherein said first retrieving means is responsive to a third user command:

(a) for generating said first output in place of said second output, and

(b) for enabling selection of a category of said categories identified in said first output in response to a said first user command.

39. Apparatus in accordance with claim 37, wherein said second retrieving means is responsive to a fourth user command:

(a) for generating said second output in place of said third output,

(b) for enabling selection of an item of said items identified in said selected category in said second output in response to a said second user command, and

(c) for retrieving for potential future output the first portion of respective items in the selected category.

40. Apparatus according to claim 37, further comprising a memory for storing items of information in categories for retrieval by said apparatus.

41. Apparatus according to claim 37, further comprising a memory at a remote location from said apparatus for storing items of information in categories for retrieval by said apparatus, and a communication link between said apparatus and said memory.

42. Apparatus for retrieving information arranged in a hierarchy of levels from a data store in accordance with instructions from a user, the apparatus comprising a memory for storing retrieved information, an output for outputting retrieved information, and an information retriever for retrieving and storing in said memory at least part of the information from the next lower level of the hierarchy available for selection by a user while information of a current level of detail is being output so that, in response to a selection by the user of information from said next lower level, the information can be read from the memory for rapidly output to the user.

43. A method of retrieving and outputting information in a plurality of different categories, each category comprising a plurality of different items, comprising:

generating a first output identifying said categories for enabling selection of a category in response to a first user command;

in response to selection of a category by a said first user command;

(a) generating a second output identifying the different items in the selected category for enabling selection of an item in response to a second user command, and

(b) retrieving for potential future output the first portion of respective items in the selected category;

in response to selection of an item by a said second user command;

(a) generating a third output containing the first portion of the selected item retrieved by the first retrieving means, and

(b) retrieving for future output the remainder of said selected item.

44. A signal carrying instructions for causing a programmable processing apparatus to become operable to perform a method as set out in claim 43.

45. A storage device storing instructions for causing a programmable processing apparatus to become operable to perform a method as set out in claim 43.