Multi-vision screen adapter

• US 6,469,746 B1
• Filed: 12/28/1993
• Issued: 10/22/2002
• Est. Priority Date: 12/28/1992
• Status: Expired due to Fees

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Maida, Yoshiaki
• Primary Examiner(s): Faile, Andrew
• Assistant Examiner(s): Srivastava, Vivek
• Application Number:
  US08/174,686
• Time in Patent Office: 3,220 Days
• Field of Search: H04/N.5445, H04/N.974, 348/564, 348/565, 348/588, 348/153, 348/159, 348/383
• US Class Current: 348/564
• CPC Class Codes: H04N 21/4316 for displaying supplemental content in a region of the screen, e.g. an advertisement in a separate window
• CPC Class Codes: H04N 21/47 End-user applications
• CPC Class Codes: H04N 5/2624 for obtaining an image which is composed of whole input images, e.g. splitscreen

Abstract

The present invention discloses a multi-vision screen display device which has a plurality of processing units each assigned to a subscreen of a display screen. The processing unit processes to display an input image on a display area which is the subscreen assigned to itself. Such processing unit comprises an image memory, a display magnification selecting unit for selecting a read-out area of the input image to be displayed on the display area, a writing unit for writing an image signal within the read-out area into the image memory at a pixel density which corresponds to a display magnification, and a reading unit for reading the image signal from the image memory at a timing which realizes to display the read-out area of the input image on the display area.

Claims

1. A multi-vision screen display device comprising:

a display screen divided into a plurality of areas for respectively displaying a plurality input images on respective preset areas, wherein each input image is output from a different one of a plurality of image sensing means;

a plurality of image processing units, each corresponding to one of said processed areas and each receiving a respective one of the input images and outputting the respective one of the input images at a timing to display it on the corresponding preset area;

an input image distributing means for distributing the input images each to a corresponding one of the image processing units; and

a display control means for controlling the corresponding image processing unit to zoom-up magnify the input image to be displayed on the corresponding preset area independently of the other areas,

wherein each one of said plurality of process units comprises an image memory, a writing means for writing the input image onto the image memory and a reading means for reading the image from the image memory,

wherein, for each image processing unit, said reading means reads the image from the image memory at a timing which realizes to display the image on the corresponding preset area, and

wherein the display control means controls a writing speed of the writing means and a reading speed of the reading means at the image processing unit which is designed to operate a zoom-up magnification of the image, and

wherein the display control means further comprises a readout area selecting means for selecting a size of a readout area within a scanning field of the input image, in which the readout area represents the image to be read from the scanning field and displayed on the corresponding preset area of the display screen.

2. The multi-vision screen display device of claim 1, wherein the display control means further comprises a readout area displacing means for displacing the readout area within the scanning field in at least one of a horizontal scanning direction and a vertical scanning direction at a predetermined speed.

3. The multi-vision screen display device of claim 1, wherein the display control means is further comprised of a readout area replacing means for dividing the scanning field into a plurality of subfields and replacing the subfield with another at a lapse of time, thereby the readout area is selected on the replacing subfield.

4. A multi-vision screen display device having a same number of processing units as subscreens of a display screen, the processing units processing to display an input image on a display area which is the subscreen assigned to each processing unit, wherein each input image is output from a different one of a plurality of image sensing means, each processing unit comprising:

an image memory;

a display magnification selecting means for selecting a read-out area of the input image to be displayed on the display area;

a writing means for writing an image signal within the selected read-out area into the image memory at a pixel density which corresponds to a display magnification; and

a reading means for reading the image signal from the image memory at a timing which realizes to display the read-out area of the input image on the display area,

wherein the writing means comprises;

a coordinate detecting means for detecting coordinates of the image signal within a scanning field at each moment;

a judging means for judging if the detected coordinates places within the read-out area of the input image;

a clock frequency changing means for changing a frequency of a sampling clock in accordance with the display magnification;

a sampling means for sampling the image signal at the frequency of the sampling clock;

a horizontal address designating means for designating a horizontal address where the image signal is written in;

a vertical address designating means for designating a vertical address where the image signal is written in; and

a write controlling means for writing the image signal sampled by the sampling means into a write-in area of the image memory designated by the horizontal address and the vertical address when the judging means judges that the coordinates of the image signal place within the read-out area of the input image.

5. The multi-vision screen display device of claim 4, wherein the sampling means is an A/D converter.

6. The multi-screen display device to claim 4, further comprising means for generating a pixel clock based on the inputted image signal,

wherein the clock frequency changing means is made up of a switch and at least one divider, and is capable of switching the display magnification between at least two kinds of display which are namely zoom-up magnification display and one-time magnification display,

wherein during zoom-up magnification display, the switch selects the pixel clock as the sampling clock,

and wherein during one-time magnification display, the switch selects a clock obtained by having the pixel clock divided by the divider as the sampling clock.

7. The multi-vision screen display device of claim 6, wherein the horizontal address designating means is a first counter which counts the sampling clock while the vertical address designating means is a second counter which counts a horizontal synchronous signal included in the image signal, in which the first counter is reset when a horizontal component of the coordinates represents a right end of the read-out area while the second counter is reset when a vertical component of the coordinates indicates a top end of the read-out area, the coordinates being detected by the coordinate detecting means.

8. The multi-vision screen display device of claim 7, wherein the coordinate detecting means is comprised of an X coordinate counter and a Y coordinate counter, the X coordinate counter counting the pixel clock until the coordinate detecting means is reset by the horizontal synchronous signal included in the image signal while the Y coordinate counter counting the horizontal synchronous signal until the coordinate detecting means is reset by the vertical synchronous signal.

9. The multi-vision screen display device of claim 8, wherein the display magnification selecting means is comprised of an output circuit for outputting coordinates of an upper left corner and a bottom right corner of the read-out area represented by the counting number of the X coordinate counter and the counting number of the Y coordinate counter.

10. The multi-vision screen display device of claim 9, wherein the judging means is a comparator which compares the counting number of the X coordinate counter and the counting number of the Y coordinator with the coordinates from the output circuit.

11. The multi-vision screen device of claim 9, wherein the output circuit comprises an X start register and a Y start register for holding the X coordinate of the start point and the Y coordinate of the start point respectively, the start point indicating the upper:

left corner of the read-out area, while an X end register and a Y end register for holding the X coordinate of the end point and the Y coordinate of the end point respectively, the end point indicating the bottom right corner of the read-out area.

12. The multi-vision screen display device of claim 11, further comprising a read-out area horizontal displacing means for updating the X coordinates in the X start register and the X end register, wherein the read-out area horizontal displacing means keeps a same difference between the X coordinates in the X start register and the X end register.

13. The multi-vision screen display device of claim 12, wherein the read-out area horizontal displacing means is comprised of a read-out area positive displacement controlling unit for updating the X coordinates in the X start register and the X end register by increasing the X coordinates at a fixed speed;

a first comparator for comparing the updated X coordinate in the X end register with the right end coordinate of read-out area of the input image at said increase of the X coordinates;

a read-out area negative displacement controlling unit for updating the X coordinates in the X start register and the X end register by decreasing the X coordinates at a fixed speed; and

a second comparator for comparing the updated X coordinate in the X start register with the left end coordinate of the read-out area of the input image at said decrease of the X coordinates, wherein

the read-out area horizontal displacing means starts operating the read-out area positive displacement controller when the X coordinate in the X start register coincides with the left end coordinate of the read-out area.

14. The multi-vision screen display device of claim 11, further comprising a read-out area vertical displacing means for updating the Y coordinates in the Y start register and the Y end register, wherein the read-out area vertical displacing means keeps a same difference between the Y coordinates in the Y start register and the Y end register.

15. The multi-vision screen display device of claim 12, wherein the read-out area vertical displacing means is comprised of a read-out area positive displacement controlling unit for updating the Y coordinates in the Y start register and the Y end register by increasing the Y coordinates at a fixed speed;

a first comparator for comparing the updated Y coordinate in the Y end register with the top end coordinate of the read-out area of the input image at said increase of the Y coordinates;

a read-out area negative displacement controlling unit for updating the Y coordinates in the Y start register and the Y end register by decreasing the X coordinates at a fixed speed; and

a second comparator for comparing the updated Y coordinate in the Y start register with the bottom end coordinate of the read-out area at said decrease of the Y coordinates, wherein

the read-out area vertical displacing means starts operating the read-out area positive displacement controlling unit when the Y coordinate in the Y start register coincides with the bottom end coordinate of the read-out area.

16. The multi-vision screen display device of claim 11, wherein the input image is shot by a monitoring camera and a screen of the monitoring camera is divided into a plurality of, areas, and the output circuit includes a circuit for replacing the coordinates of the start point and the end point of the read-out area on one area, the coordinates held in the X start register, the Y start register, the X end register, and the Y end register, with the coordinates of the start and the end points of the read-out are on another area.

17. A multi-vision screen display device having a same number of processing units as subscreens of a display screen, the processing units processing to display an input image on a display area which is the subscreen assigned to each processing unit, wherein each input image is output from a different one of a plurality of image sensing means, each processing unit comprising:

an image memory;

a display magnification selecting means for selecting a read-out area of the input image to be displayed on the display area;

a writing means for writing an image signal within the selected read-out area into the image memory at a pixel density which corresponds to a display magnification; and

a reading means for reading the image signal from the image memory at a timing which realizes to display the read-out area of the input image on the display area,

said multi-vision screen display device further including an image sensor for computing a sum of a luminance signal of a pixel placing within a fixed range of the read-out area, and generating an alarm signal when a difference between the sum at a last scanning field and the sum at a current scanning field is larger than a predetermined threshold value.

18. The multi-vision screen display device of claim 17, wherein the image sensor is comprised of an adding means for adding the luminance signal of every pixel within the fixed range of the read-out area at the current scanning field;

a holding means for holding said addition result for the sum at the last scanning field;

a difference computing means for computing the difference between the addition result held in the holding means and the addition result from the adding means; and

an alarm signal output circuit for comparing the difference from the difference computing means with the threshold value, then outputting the alarm signal when the difference is larger than the threshold value.

19. The multi-vision screen display device of claim 18, further comprising:

a zoom-out display selection controlling means for selecting the zoom-out display upon receipt of the alarm signal from the image sensor;

a writing means for writing an image signal within the selected read-out area into the image memory at a pixel density which corresponds to a display magnification; and

a reading means for reading the image signal from the image memory at a timing which realizes to display the read-out area of the input image on the display area.

20. A multi-vision screen display device which processes an input image from a plurality of monitoring cameras by a same number of processing units as the monitoring cameras and displays each input image on a different subscreen of a multi-vision screen simultaneously, each processing unit comprising:

an image memory; and

a display magnification selection means for selecting a read-out area within a scanning area of a screen at the monitoring camera, the read-out area to be displayed on a display area being the subscreen assigned to the processing unit;

a writing means for writing an image signal within the read-out area into the image memory at a pixel density which corresponds to a display magnification; and

a reading means for reading the image signal from the image memory at a timing which realizes to display the read-out area of the input image on the display area, said multi-vision screen display device further comprising;

a connection switching means placed between the monitoring camera and each processing unit for replacing a connection between the monitoring camera and the processing unit with another; and

a read-out area replacing means for replacing the read-out area by another and a connection switching means for replacing a connection between the monitoring camera and the processing unit by another, wherein the read-out area is determined in accordance with the connection switching means which determines the number of the processing units where the monitoring camera provides the input image.

21. The multi-vision screen display device of claim 20, wherein the writing means comprises:

a coordinate detecting means for detecting coordinates of the image signal within a scanning field at each moment;

a judging means for judging if the detected coordinates are placed within the read-out area of the input image;

a clock frequency changing means for changing a frequency of a sampling clock in accordance with the display magnification;

a sampling means for sampling the image signal at the frequency of the sampling clock;

a horizontal address designating means for designating a horizontal address wherein the image signal is written in;

a vertical address designating means for designating a vertical address where the image signal is written in; and

a write controlling means for writing the image signal sampled by the sampling means into a write-in area of the image memory designated by the horizontal address and the vertical address when the judging means judges that the coordinates of the image signal are placed within the read-out area of the input image.

22. A multi-vision screen display device comprising:

a plurality of image processing units;

an input image distributing means for distributing input images to the plurality of image processing units;

a display for displaying on a display screen a plurality of images respectively output from the plurality of image processing units, the display screen being divided into a plurality of display areas which respectively correspond to the plurality of image processing units; and

a magnification receiving means for receiving magnifications which each are separately specified for one of the plurality of images respectively output from the plurality of image processing units, wherein

each image processing unit includes;

an image memory;

a writing means for writing an input image distributed by the input image distributing means into the image memory with a magnification received by the magnification receiving means and being specified for the present image processing unit,

a write size restricting means for restricting a size of an area in the image memory, into which the input image is written, to a size of a display area assigned to the present image processing unit; and

a reading means for reading the input image from the image memory with a timing when the input image is displayed on the display area assigned to the present image processing unit.

23. The multi-vision screen display device of claim 22, wherein the write size restricting means includes:

a write start register for storing a write start coordinate of the area in the image memory into which the input image is written; and

a write end register for storing a write end coordinate of the area in the image memory into which the input image is written, wherein

the writing means includes;

a synchronous separation unit for extracting a horizontal synchronous signal and a vertical synchronous signal from the input image distributed by the input image distributing means and for generating a pixel clock;

a clock pulse generating unit for generating a clock pulse using the pixel clock generated by the synchronous separation unit, the clock pulse corresponding to the magnification specified for the present image processing unit received by the magnification receiving means;

an A/D converting unit for sampling sample signals from the input image distributed by the input image distributing means using the clock pulse generated by the clock pulse generating unit and converting the sampled sample signals to digital image signals;

a scanning position coordinate generating unit for generating a coordinate indicating a scanning position of the input signal for each scanning time, using the pixel clock, the horizontal synchronous signal, and the vertical synchronous signal;

a write enabling unit for enabling the writing means to write the input image into the image memory when the coordinate generated by the scanning position coordinate generating unit is in a range from the write start coordinate to the write end coordinate; and

a write address generating unit for generating a write address by counting each clock pulse generated by the clock pulse generating unit, wherein

the digital image signals output from the AID converting unit are written into a location indicated by the write address generated by the write address generating unit.

24. The multi-vision screen display device of claim 23, wherein the reading means includes:

a display area coordinate storing unit for storing a start coordinate and an end coordinate of the display area assigned to the present image processing unit;

a display address generating unit for generating a display address using the pixel clock, the horizontal synchronous signal, and the vertical synchronous signal of the input image distributed to the present image processing unit;

a read enabling unit for enabling the reading means to read the input image from the image memory when the display coordinate is in a range from the start coordinate to the end coordinate of the display area assigned to the present image processing unit; and

a read address generating unit for generating a read address synchronizing with a clock which is equivalent to the pixel clock multiplied by an integer when the read enabling unit enables the reading means to read the input image and for supplying the generated read address to the image memory; and

a D/A converting unit for converting digital image signals read from the image memory to analog image signals and outputting the converted analog image signals.