Electronic blackboard

• US 5,181,129 A
• Filed: 03/08/1990
• Issued: 01/19/1993
• Est. Priority Date: 03/17/1989
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Akimaru, Susumu, Sato, Kunio, Hoshi, Nobuyoshi, Hori, Yasuro
• Primary Examiner(s): Coles, Sr., Edward L.
• Assistant Examiner(s): Lee, Thomas D.
• Application Number:
  US07/490,467
• Time in Patent Office: 1,048 Days
• Field of Search: 358/494, 358/496, 358/497, 358/498, 358/486, 358/452, 358/400, 358/401, 358/471, 358/474, 358/296, 358/300, 358/302
• US Class Current: 358/494
• CPC Class Codes: H04N 1/0402 Scanning different formats; Scanning with different densities of dots per unit length, e.g. different numbers of dots per inch (dpi); Conversion of scanning standards H04N1/00283 takes precedence; picture signal circuits for modification of image resolution H04N1/3935, H04N1/40068
• CPC Class Codes: H04N 1/0417 Conversion of standards
• CPC Class Codes: H04N 1/1215 Feeding using one or more cylindrical platens or rollers in the immediate vicinity of the main scanning line
• CPC Class Codes: H04N 1/1255 Electronic copy boards
• CPC Class Codes: H04N 1/193 using electrically scanned linear arrays , e.g. linear CCD arrays
• CPC Class Codes: H04N 2201/0438 Scanning displays; Scanning large surfaces, e.g. projection screens, writing boards

Abstract

An electronic blackboard having a copy function, and an edit function or communication function. A single reading unit is used in common for both reading an image on a flat board and reading an image or an original document. Reflected light from the flat board and from the original document is converged and projected onto a light receiving surface of a single photoelectric conversion element. An image of the flat board of the original document can be selectively read, or the composite image of both the flat board and original document can be read. Further, the electrical signal corresponding to the image can be modulated and transmitted, and a received electrical signal can be demodulated to reproduce a corresponding image. Furthermore, in accordance with the electrical signal obtained by photoelectrically converting an image, the layout of the image on the flat board can be determined and edited to change the shape of the image.

Claims

1. An electronic print board comprising:

a flat board having a background color and adapted for presentation thereon of an image in a different color;

input means, including a single photoelectric conversion element, for scanning in a single scanning line an image presented on said flat board or in substantially the same scanning line an image on an original document and converting the scanned image into an electrical signal;

image converging and projecting means for converging the reflected light from the scanning line on the image written on said flat board or from the scanning line on the image on the original document to provide on said single photoelectric conversion element in substantially equal sizes a projected image of the scanning line on the image on the original document or a projected image of the scanning line on the image on said flat board;

recording means responsive to the electrical signal for recording the projected image; and

flat board writing means responsive to the electrical signal for presenting on said flat board an image of the projected image.

2. An electronic print board according to claim 1, wherein said image converging and projecting means comprises a first optical lens for said original document and a second optical lens for said flat board.

3. An electronic print board according to claim 2, wherein each optical lens is a fixed focal length lens.

4. An electronic print board as claimed in claim 1, further comprising:

a communication unit for encoding, modulating and transmitting the electrical signal from said input means and for demodulating and decoding a received electrical signal to produce an image;

an operation unit for entry of instructions to designate the operation of and activate said print board; and

a board control unit for controlling the operation of said print board in accordance with instructions from said operation unit.

5. An electronic print board as claimed in claim 1, further comprising:

an editing unit for editing the electrical signal from said input means to provide an edited electrical signal representative of an image different from the image of the electrical signal from said input means.

6. An electronic print board comprising:

a flat board having a background color and adapted for presentation thereon of an image in a different color;

input means, including a single photoelectric conversion element, for converting reflected light from an image presented on said flat board or an image on an original document into an electrical signal;

image converging and projecting means, including a variable focal length optical lens, for converging the reflected light from the image written on said flat board or from the image on the original document to provide on said single photoelectric conversion element in substantially equal sizes a projected image of the image on the original document or a projected image of the image on said flat board;

recording means responsive to the electrical signal for recording the projected image; and

flat board writing means responsive to the electrical signal for presenting on said flat board an image of the projected image.

7. An electronic print board comprising:

a flat board having a background color and adapted for presentation thereon of an image in a different color;

input means, including a single photoelectric conversion element, for converting reflected light from an image presented on said flat board or an image on an original document into an electrical signal;

image converging and projecting means for illuminating said flat board and the original document and converging the reflected light from the image written on said flat board or from the image on the original document such that the optical path of the light illuminating and reflected by said flat board and the light illuminating and reflected by the original document is substantially the same, to provide on said single photoelectric conversion element a projected image of the image on the original document or a projected image of the image on said flat board;

recording means responsive to the electrical signal for recording the projected image; and

flat board writing means responsive to the electrical signal for presenting on said flat board an image of the projected image.

8. An electronic print board as claimed in claim 7, further comprising:

a communication unit for encoding, modulating and transmitting the electrical signal from said input means and for demodulating and decoding a received electrical signal to produce an image;

an operation unit for entry of instructions to designate the operation of and activate said print board; and

a board control unit for controlling the operation of said print board in accordance with instructions from said operation unit.

9. An electronic print board as claimed in claim 8, further comprising:

an editing unit for editing the electrical signal from said input means to provide an edited electrical signal representative of an image different from the image of the electrical signal from said input means.

10. An electronic print board as claimed in claim 7, further comprising:

an editing unit for editing the electrical signal from said input means to provide an edited electrical signal representative of an image different from the image of the electrical signal from said input means.

11. An electronic print board comprising:

a flat board having a background color and adapted for presentation thereon of an image in a different color;

input means, including a single photoelectric conversion element, for converting light projected thereon into an electrical signal;

image converging and projecting means for simultaneously illuminating both said flat board and an original document and simultaneously converging both the reflected light from the image written on said flat board and the reflected light from an image on the original document such that the optical path of the light illuminating and reflected by said flat board and the optical path of the light illuminating and reflected by the original document are substantially different, to provide on said single photoelectric conversion element a combined projected image of the image on the original document and the image on said flat board;

recording means responsive to the electrical signal for recording the combined projected image;

flat board writing means responsive to the electrical signal for presenting on said flat board an image of the combined projected image;

a communication unit for encoding, modulating and transmitting the electrical signal from said input means and for demodulating and decoding a received electrical signal to produce an image;

an operation unit for entry of instructions to designate the operation of and activate said electronic print board; and

a board control unit for controlling the operation of said electronic print board in accordance with instructions from said operation unit.

12. An electronic print board comprising:

a flat board having a background color and adapted for presentation thereon of an image in a different color;

input means, including a single photoelectric conversion element, for converting light projected thereon into an electrical signal;

image converging and projecting means for simultaneously illuminating both said flat board and an original document and simultaneously converging both the reflected light from the image written on said flat board and the reflected light from an image on the original document such that the optical path of the light illuminating and reflected by said flat board and the optical path of the light illuminating and reflected by the original document are substantially different, to provide on said single photoelectric conversion element a combined projected image of the image on the original document and the image on said flat board;

recording means responsive to the electrical signal for recording the combined projected image;

flat board writing means responsive to the electrical signal for presenting on said flat board an image of the combined projected image;

an editing unit for editing the electrical signal from said input means to provide an edited signal representative of an image different from the image of the electrical signal from said input means;

an operation unit for entry of instructions to designate the operation of and activate said electronic print board; and

a board control unit for controling the operation of said electronic print board in accordance with instructions from said operation unit.

13. An electronic print board as claimed in claim 12, further comprising:

a communication unit for encoding, modulating and transmitting a selected one of the electrical signal from said input means and the edited electrical signal and for demodulating and decoding a received electrical signal to produce an image.