Image forming apparatus

• US 4,658,284 A
• Filed: 01/02/1985
• Issued: 04/14/1987
• Est. Priority Date: 01/11/1984
• Status: Expired due to Term

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sasaki, Takashi, Kawamura, Hideaki, Sakurada, Nobuaki
• Primary Examiner(s): Britton, Howard W.
• Application Number:
  US06/688,429
• Time in Patent Office: 832 Days
• Field of Search: 358/280, 358/78, 358/28, 358/23, 358/24, 358/140, 358/77, 358/287, 358/11, 358/310
• US Class Current: 348/458
• CPC Class Codes: H04N 7/0135 involving interpolation processes interpolation-based image scaling G06T3/4007; interpolation for video coding H04N19/587, H04N19/59

Abstract

There is disclosed an image forming apparatus for obtaining an image from a television image with 625 horizontal scanning lines with a circuitry substantially same as that for obtaining an image from a television image with 525 horizontal scanning lines. In this apparatus the samples from six scanning lines are converted to form five scanning lines by means of sampling circuit and converting circuit.

Claims

1. An image forming apparatus comprising:

generating means for generating an analog video signal including a large number of horizontal scanning lines;

sampling signal generating means for generating a sampling signal to sample said video signal point by point with respect to each horizontal scanning line;

analog-digital converting means for converting said analog video signal into a digital value in response to said sampling signal;

memory means for storing said digital value;

pixel number converting means, including a multiplier unit in which each digital value in said memory means is multiplied by a predetermined coefficient and an adder unit in which the multiplied results of consecutive digital values of said multiplier unit are added for converting six digital values in said memory means into five output values; and

image forming means for image formation in response to signals corresponding to said output values of said converting means.

2. An image forming apparatus according to claim 1, wherein said video signal is a CCIR video signal.

3. An image forming apparatus according to claim 1, wherein said video signal has 625 horizontal scanning lines per frame.

4. An image forming apparatus according to claim 1, wherein said video signal is an NTSC signal or a CCIR signal, and the conversion by said converting means is not conducted for said NTSC signal.

5. An image forming apparatus according to claim 1, wherein said image forming means is adapted to form a hard copy image on a recording medium.

6. An image forming apparatus according to claim 5, wherein said image forming means includes an ink jet recorder.

7. An image processing apparatus comprising:

input means for inputting an NTSC video signal or a CCIR video signal;

sampling signal generating means for generating a sampling signal to sample the video signal point by point with respect to each horizontal scanning line of said NTSC signal or said CCIR signal;

analog-digital converting means for converting said analog video signal into a digital value in response to said sampling signal;

memory means for storing said digital value;

pixel number converting means, including a multiplier unit in which each digital value in said memory means is multiplied by a predetermined coefficient and an adder unit in which the multiplier results of consecutive digital values of said multiplier unit are added for converting the six digital values in said memory means into five output values; and

control means adapted to activate said converting means when said video signal is said CCIR video signal and bypass said converting means when said video signal is said NTSC video signal.

8. An image processing apparatus according to claim 7, further comprising image forming means for forming an image in response to the output of said converting means.

9. An image processing apparatus according to claim 8, wherein said image forming means is adapted to form a hard copy image on a recording medium.

10. An image processing apparatus according to claim 9, wherein said image forming means includes an ink jet recorder.