Image forming apparatus

• US 6,231,155 B1
• Filed: 08/24/1998
• Issued: 05/15/2001
• Est. Priority Date: 10/05/1989
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Matsuo, Takayuki, Udagawa, Yutaka, Takayanagi, Yoshiaki, Numata, Yasuhiro, Maeshima, Katsuyoshi, Matsubara, Miyuki
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): HALLACHER, CRAIG ALAN
• Application Number:
  US09/138,766
• Time in Patent Office: 995 Days
• Field of Search: 399/12, 347/9, 347/14, 347/19, 400/61, 400/70, 400/76
• US Class Current: 347/19
• CPC Class Codes: B41J 2/17546 electronically
• CPC Class Codes: B41J 2202/17 Readable information on the head
• CPC Class Codes: B41J 25/34 Bodily-changeable print heads or carriages
• CPC Class Codes: G06K 15/102 using ink jet print heads
• CPC Class Codes: G06K 2215/0094 Colour printing

Abstract

An image recording apparatus includes a recording unit integrally having an image forming recording head and a memory for storing a correction datum for correcting non-uniform image formation property; a reader for reading the correction datum from the memory; and a device for changing image forming conditions in accordance with the correction datum read by the reader. The apparatus also can alter the image forming conditions changed by the changing device when the non-uniformity of the recording unit changes.

Claims

1. An image forming apparatus comprising:

a recording head unit having a plurality of recording elements for depositing a coloring material in response to driving signals supplied to individual recording elements to form an image;

an image processor for receiving image data and for determining whether to drive individual recording elements in accordance with the image data;

drivers, responsive to outputs of said image processor, for generating and supplying the driving signals to such recording elements as are determined to be driven by said image processor to deposit the coloring material; and

memory means, in said recording head unit, for storing a driver datum for determining a waveform of the driving signals and for storing correction data, which corresponds to each of the plurality of recording elements, respectively, to be supplied to said image processor for correcting the determination of said image processor,

wherein said image processor determines whether to drive individual recording elements based on the image data corrected by the correction data supplied from said memory means, and said drivers supply to said recording elements the drive signals determined by the driver datum stored in said memory means to drive said recording elements.

2. An apparatus according to claim 1, wherein the image data is multi-level data indicative of tone gradation levels, and wherein said image processor corrects a level of the tone gradation indicated by the image data based on the correction data supplied from said memory means and determines whether to drive individual recording elements based on the corrected image data.

3. An apparatus according to claim 1, wherein the driver datum stored in said memory means is a datum for determining a waveform of the driving signal common to a plurality of recording elements of said recording head unit.

4. An apparatus according to claim 1, wherein said recording head unit is detachably mountable to said apparatus.

5. An apparatus according to claim 4, further comprising means for discriminating exchange of said recording head unit.

6. An apparatus according to claim 1, wherein said recording head unit is an ink jet recording head having a plurality of nozzles through which ink is ejected by driving the plurality of recording elements.

7. An apparatus according to claim 6, wherein said ink jet recording head ejects the ink through the nozzles using thermal energy.

8. A recording head unit for an image forming apparatus, comprising:

a plurality of recording elements for depositing a coloring material in response to driving signals supplied to individual recording elements to form an image, wherein said image forming apparatus includes an image processor for receiving image data and for determining whether to drive individual recording elements in accordance with the image data, and drivers, responsive to outputs of the image processor, for generating and supplying the driving signals to such recording elements as are determined to be driven by the image processor to deposit the coloring material; and

memory means, in said recording head unit, for storing a driver datum for determining a waveform of the driving signals and for storing correction data, which corresponds to each of the plurality of recording elements, respectively, to be supplied to the image processor for correcting the determination of said image processor,

wherein said image processor determines whether to drive individual recording elements based on the image data corrected by the correction data supplied from said memory means, and said drivers supply to said recording elements the drive signals determined by the driver datum stored in said memory means to drive said recording elements.

9. A recording head unit according to claim 8, wherein the image data is multi-level data indicative of tone gradation levels, and wherein said image processor corrects a level of the tone gradation indicated by the image data based on the correction data supplied from said memory means and determines whether to drive individual recording elements based on the corrected image data.

10. A recording head unit according to claim 8, wherein the driver datum stored in said memory means is a datum for determining a waveform of the driving signal common to a plurality of said recording elements.

11. A recording head unit according to claim 8, wherein said recording head unit is detachably mountable to said image forming apparatus.

12. A recording head unit according to claim 11, further comprising a plurality of nozzles through which ink is ejected by driving said plurality of recording elements.

13. A recording head unit according to claim 8, wherein the ink is ejected through said nozzles using thermal energy.