IMAGE FORMING APPARATUS

• US 20080138094A1
• Filed: 12/12/2007
• Published: 06/12/2008
• Est. Priority Date: 12/12/2006
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: SHIORI, Jun, Takahashi, Yutaka, Mizutani, Takehide, Kasai, Tadashi, Tano, Atsushi, Sugiyama, Toshihiro
• Granted Patent: US 7,965,954 B2
• Time in Patent Office: Days
• US Class Current: 399/9
• CPC Class Codes: G03G 15/065 Arrangements for controlling the potential of the developing electrode
• CPC Class Codes: G03G 15/5041 Detecting a toner image, e.g. density, toner coverage, using a test patch G03G15/553 takes precedence
• CPC Class Codes: G03G 2215/0132 vertical medium transport path at the secondary transfer

Abstract

A control unit controls a device that executes an image forming process, compares changes of each toner adhesion amount in an image-density-detection pattern image when a developing-bias control condition is changed, with respect to a toner adhesion amount in an image-density-detection pattern image in a normal status, performs a malfunction-occurrence prediction process according to the degree of each change of the densities, and displays the result.

Claims

1. An image forming apparatus comprising:

an image forming unit that forms an electrostatic latent image on a photosensitive element by an electrophotographic process, and causes toner to adhere to the electrostatic latent image to form a visible image; and

a control unit that controls the image forming unit, wherein

at least a toner-adhesion-amount detector that detects a toner adhesion amount in an image-density-detection pattern image formed on the photosensitive element, an operating unit through which image formation is instructed, and a detection sensor that detects temperature and humidity in proximity of the image formation are connected to an input side of the control unit,

at least a developing bias control unit that controls a developing-bias control condition in a developing process, a display unit that can display thereon a malfunction, and a communicating unit that displays a malfunction on an external device via a network are connected to an output side of the control unit, and

the control unit compares changes of a toner adhesion amount in the image-density-detection pattern image when the developing-bias control condition is changed with respect to a toner adhesion amount in the image-density-detection pattern image in a normal status, performs a malfunction-occurrence prediction process according to a degree of each of the changes in density, and displays a result of the malfunction-occurrence prediction process.

2. The image forming apparatus according to claim 1, wherein the control unit keeps a condition provided in a device used in a charging process to be constant when the developing-bias control condition is changed, and predicts a malfunction occurrence in the image forming unit used in the charging process.

3. The image forming apparatus according to claim 1, wherein the control unit changes an imaging condition in a process other than a charging process to a condition under which the toner adhesion amount is made appropriate, according to a result of predicting a malfunction occurrence in the image forming unit used in the charging process.

4. The image forming apparatus according to claim 1, wherein the control unit causes a server connected thereto through the communicating unit via the network to output and store therein prediction of a malfunction occurrence and to display thereon the prediction of the malfunction occurrence.

5. The image forming apparatus according to claim 1, wherein the control unit causes a display unit of the operating unit to output and display thereon prediction of a malfunction occurrence.

6. The image forming apparatus according to claim 1, wherein the control unit executes the malfunction-occurrence prediction process according to an output from the detection sensor or the number of outputs of formed images.

7. The image forming apparatus according to claim 1, wherein the control unit executes the malfunction-occurrence prediction process according to an instruction from the operating unit.

8. The image forming apparatus according to claim 1, wherein

the control unit further includes an information storage unit that stores therein a result of predicting a malfunction occurrence, and

the result of predicting the malfunction occurrence stored in the information storage unit is readable.

9. An image forming apparatus comprising:

an image input unit that inputs image data;

an image forming unit that forms an image on a recording medium based on input image data;

an image reading unit that reads the recording medium on which the image is formed, and outputs read image data;

an abnormality-detection-image output unit that outputs abnormality-detection image data with which an abnormal image easily occurs caused by a charging unit of the image forming unit;

a comparing unit that compares image data output from the image reading unit by reading the recording medium on which the image is formed based on the abnormality-detection image data output by the abnormality-detection-image output unit with the input image data, and outputs a comparison result; and

a determining unit that determines whether there is a malfunction of the charging unit based on the comparison result.

10. The image forming apparatus according to claim 9, wherein a method of outputting the abnormality-detection image data by the abnormality-detection-image output unit includes outputting the abnormality-detection image data by changing a background potential that is a difference between a surface potential of the photosensitive element and a developing bias, so that a malfunction of the charging unit can be detected before an abnormality due to the charging unit appears in an output image formed on the recording medium.

11. The image forming apparatus according to claim 9, wherein the comparing unit divides the abnormality-detection image data and the image data output from the image forming unit into a plurality of blocks, and performs a pattern matching on each divided block.

12. The image forming apparatus according to claim 9, wherein the abnormality-detection-image output unit outputs the abnormality-detection image data at an output time determined based on a use environment including temperature and humidity of a location where the image forming apparatus is installed, a color ratio, and number of image outputs.

13. The image forming apparatus according to claim 9, wherein the image reading unit automatically reads the image recorded on the recording medium when the recording medium with the image recorded thereon based on the abnormality-detection image data is ejected.

14. The image forming apparatus according to claim 9, further comprising a communicating unit that transmits data to at least one of a user, a device manager, and a service center via a network, wherein

the comparing unit includes a converting unit that converts the comparison result to a numerical value according to a degree of abnormality, and

the communicating unit transmits at least one of read image data, the comparison result, and the numerical value to at least one of the user, the device manager, and the service center via the network when the numerical value matches with a predetermined value.

15. The image forming apparatus according to claim 14, wherein the communicating unit makes at least a service call as a notification about a determination result by the determining unit.

16. The image forming apparatus according to claim 14, further comprising a display unit, wherein information on the determination result is displayed on the display unit when the determination result is a predetermined value.

17. The image forming apparatus according to claim 9, further comprising a resetting unit that automatically resets each value contributed to imaging including a background potential to a value with which an abnormal image due to charging hardly appears, based on the comparison result, and that sets a setting with which an abnormal image due to charging hardly appears in an image in ordinary use during the time when the charging unit or a unit including the charging unit is replaced.

18. The image forming apparatus according to claim 9, wherein the abnormality-detection-image output unit describes information indicating that an output image from the abnormality-detection image data is not charged in the recording medium.

19. The image forming apparatus according to claim 14, wherein the charging unit or a device unit that includes the charging unit includes an information recording medium and a unit that writes the comparison result in the information recording medium.