Display apparatus and method

• US 6,067,645 A
• Filed: 05/30/1996
• Issued: 05/23/2000
• Est. Priority Date: 06/02/1995
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ohno, Tomoyuki, Mizutome, Atsushi, Mori, Hideo, Yamamoto, Takashi, Yoshida, Akio, Murayama, Kazuhiko
• Primary Examiner(s): Le, Dieu-Minh T.
• Application Number:
  US08/655,146
• Time in Patent Office: 1,454 Days
• Field of Search: 395/185.1, 395/183.22, 395/501, 395/788, 395/326, 395/185.01, 395/185.09, 345/97, 345/98, 345/185, 345/418, 345/326, 345/333, 345/156, 345/501, 345/520, 364/413.22, 364/237.2, 364/237.5, 364/146, 714/57, 714/24
• US Class Current: 714/57
• CPC Class Codes: G09G 2310/04 Partial updating of the display screen
• CPC Class Codes: G09G 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2330/02 Details of power systems and of start or stop of display operation
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 2370/045 using multiple communication channels, e.g. parallel and serial
• CPC Class Codes: G09G 2370/22 Detection of presence or absence of input display information or of connection or disconnection of a corresponding information source
• CPC Class Codes: G09G 3/2059 using error diffusion
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3629 using liquid crystals having memory effects, e.g. ferroelectric liquid crystals
• CPC Class Codes: G09G 3/3681 suitable for passive matrices only
• CPC Class Codes: G09G 3/3692 suitable for passive matrices only
• CPC Class Codes: G09G 3/3696 Generation of voltages supplied to electrode drivers
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04

Abstract

A display apparatus includes a communication device for executing a communication with a host computer via an interface cable. The display apparatus also includes a display having a display screen for displaying image data transferred in synchronism with display timing from the host computer via the interface cable, a connector connectable to the interface cable that communicates with the host computer, and a detector for detecting whether or not the connector is connected to the host computer via the interface cable. A connection/disconnection state of the interface cable is recognized on the basis of the detection result.

Claims

1. A display apparatus which includes communication means for executing a communication with a host computer via an interface cable, comprising:

a display including a display screen for displaying image data transferred in synchronism with display timing from the host computer via the interface cable;

a connector connectable to the interface cable that communicates with the host computer;

detection means for detecting whether or not said connector is connected to the host computer via the interface cable;

recognition means for recognizing a connection/disconnection state of the interface cable on the basis of a detection result of said detection means; and

information means for informing a recognition result of said recognition means.

2. The apparatus according to claim 1, further comprising indication means for indicating a mode, wherein said information means informs the recognition result of the connection/disconnection state of the interface cable by changing the indication mode of said indication means, which is arranged in addition to said display screen.

3. The apparatus according to claim 2, wherein said indication means comprises a light-emitting diode, and said information means informs the recognition result of the connection/disconnection state of the interface cable by turning off said light-emitting diode upon detection of the disconnection of the interface cable.

4. The apparatus according to claim 2, wherein said display has a function of holding a display state of an image.

5. The apparatus according to claim 4, wherein said display comprises a ferroelectric liquid crystal display.

6. The apparatus according to claim 5, wherein said display comprises a backlight, displays information using light emitted by said backlight and transmitted through said ferroelectric liquid crystal display, and can operate at least in a display operation mode in which information is displayed by turning on said backlight and in a power saving operation mode in which said backlight is turned off, and said indication means is controlled to blink.

7. The apparatus according to claim 1, further comprising means for not updating an image displayed on said display screen when said recognition means detects the disconnection of the interface cable.

8. The apparatus according to claim 1, further comprising initialization means for performing initialization processing when said recognition means detects the disconnection of the interface cable.

9. A display method for a display apparatus which comprises a connector and communication means for executing a communication with a host computer via an interface cable connected to the connector, with the display apparatus including a display having a display screen for displaying image data transferred in synchronism with display timing from the host computer via the interface cable, said method comprising the steps of:

detecting whether or not the connector is connected to the host computer via the interface cable;

recognizing a connection/disconnection state of the interface cable to the connector; and

informing a recognition result.

10. The method according to claim 9, wherein the informing step includes the step of informing the recognition result of the connection/disconnection state of the interface cable by changing an indication mode of an indication means arranged in addition to the display screen.

11. The method according to claim 10, further comprising the step of providing the indication means with a light-emitting diode, and wherein the informing step includes the step of informing the recognition result of the connection/disconnection state of the interface cable by turning off the light-emitting diode.

12. The method according to claim 11, further comprising the step of providing the display with a ferroelectric liquid crystal display which comprises a backlight and has a function of holding a display state of an image, and can operate at least in a display operation mode in which information is displayed by turning on the backlight and in a power saving operation mode in which the backlight is turned off, and wherein the indication means is controlled to blink.

13. The method according to claim 9, further comprising the step of not updating an image displayed on the display screen when the disconnection of the interface cable is recognized.

14. A computer program product comprises a computer usable medium having computer readable program code embodied on said medium for executing and integrating in a display apparatus having a connector for connecting with a host computer and for receiving images to be displayed that are transferred in synchronism with display timing from the host computer via an interface cable, said computer program product comprising:

detection procedure code means for detecting whether or not the connector is connected to the host computer via the interface cable;

recognition procedure code means for recognizing a connection/disconnection state of the interface cable to the connector which connects the interface cable in communication with the host computer; and

informing step procedure code means for informing a recognition result.

15. The product according to claim 14, further comprising code means for not updating an image displayed on the display screen when the disconnection of the interface cable is recognized.

16. Information processing system having a host computer and a display apparatus, with

said host computer comprising:

a first connector for connecting an interface cable that performs a communication with said display apparatus; and

display supply means for supplying display data to said display apparatus via said interface cable, and

said display apparatus comprising;

a second connector for connecting said interface cable that performs the communication with said host computer;

a display including a display screen for displaying image data transferred in synchronism with display timing from the second connector;

detection means for detecting whether or not said second connector is connected to said host computer via said interface cable;

recognition means for recognizing a connection/disconnection state of said interface cable on the basis of a detection result of said detection means; and

information means for informing a recognition result of said recognition means.

17. An information processing system according to claim 16, further comprising indication means for indicating a mode, wherein said information means informs the recognition result of the connection/disconnection state of said interface cable by changing the indication mode of said indication means, which is arranged in addition to the display screen.

18. An information processing system according to claim 17, wherein said indication means comprises a light-emitting diode, and said information means informs the recognition result of the connection/disconnection state of said interface cable by turning off said light-emitting diode upon detection of the disconnection of said interface cable.

19. An information processing system according to claim 17, wherein said display has a function of holding a display state of an image.

20. An information processing system according to claim 19, wherein said display comprises a ferroelectric liquid crystal display.

21. An information processing system according to claim 20, wherein said display comprises a backlight, displays information using light emitted by said backlight and transmitted through said ferroelectric liquid crystal display, and can operate at least in a display operation mode in which information is displayed by turning on said backlight and in a power saving operation mode in which said backlight is turned off, and said indication means is controlled to blink.

22. An information processing system according to claim 16, further comprising means for not updating an image displayed on said display screen when said recognition means detects the disconnection of said interface cable.

23. An information processing system according to claim 16, further comprising initialization means for performing initialization processing when said recognition means detects the disconnection of said interface cable.