Document reading apparatus and an image formation apparatus

• US 20060203306A1
• Filed: 02/21/2006
• Published: 09/14/2006
• Est. Priority Date: 02/28/2005
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Hoshi, Kazunori
• Granted Patent: US 7,843,610 B2
• Time in Patent Office: Days
• US Class Current: 358/497
• CPC Class Codes: H04N 1/00002 Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for error detection, error correction or monitoring in digital computers or digital computer components G06F11/00
• CPC Class Codes: H04N 1/00013 Reading apparatus
• CPC Class Codes: H04N 1/00031 Testing, i.e. determining the result of a trial H04N1/00029 takes precedence; using test signals for transmission mode changing H04N2201/33371
• CPC Class Codes: H04N 1/00055 automatically on a periodic basis
• CPC Class Codes: H04N 1/00063 using at least a part of the apparatus itself, e.g. self-testing
• CPC Class Codes: H04N 1/00087 Setting or calibrating picture signal circuits H04N1/40
• CPC Class Codes: H04N 1/00885 Power supply means, e.g. arrangements for the control of power supply to the apparatus or components thereof
• CPC Class Codes: H04N 1/00896 using a low-power mode, e.g. standby
• CPC Class Codes: H04N 1/00933 Timing control or synchronising H04N1/00928, H04N1/00931, H04N1/00954 and H04N1/0096 take precedence
• CPC Class Codes: H04N 2201/0094 Multifunctional device, i.e. a device capable of all of reading, reproducing, copying, facsimile transception, file transception

Abstract

A document reading apparatus is disclosed. The document reading apparatus includes a scanner; an energy-saving power supply unit; an energy-saving control unit; a clock IC; an output compensation unit for updating digital conversion parameters including image signal amplification gain such that image data of a reference white board read by a CCD of the scanner are made into a proper value; and an output compensation controlling unit. The output compensation controlling unit reads time data when an operation mode is shifted from pause mode to waiting mode, stores the digital conversion parameters updated by the output compensation unit in a non-volatile memory, updates operation time with the present time if the elapsed time from a previous operation time stored in the non-volatile memory is equal to or greater than a setup value, and uses the digital conversion parameters stored in the non-volatile memory as they are, if the elapsed time from the previous operation time stored in the non-volatile memory is less than the setup value.

Claims

1. A document reading apparatus, comprising:

a scanner for scanning a document;

a power supply unit for providing operating voltages to the scanner in a waiting mode for reading the document, and suspending the operating voltages in a pause mode;

an input unit for inputting operation directions to the scanner;

an energy-saving control unit for switching the power supply unit to the pause mode if there is no operation direction being issued and the waiting mode lasts a predetermined period, and for switching the power supply unit to the waiting mode if there is an operation direction being issued during the pause mode; and

a clock unit for counting time and for generating time data;

wherein the scanner includes

an image sensor for converting image light reflected from the document into an image signal;

an optical unit for projecting the image light of the document onto the image sensor;

an image signal processing unit for converting the image signal into digital image data;

a reference white plate;

an output compensation unit for updating digital conversion parameters including an image signal amplification gain of the image signal processing unit so that the image data of the reference white plate projected onto the image sensor by the optical unit and converted by the image signal processing unit may become a proper value; and

an output compensation control unit for controlling the output compensation, wherein

the time data of the clock unit are read when an operating voltage for reading the document is provided pursuant to the power supply unit being switched to the waiting mode;

whether an elapsed time from the last operation time held in a non-volatile memory is equal to or greater than a predetermined value is determined;

if the determination is affirmative, the digital conversion parameters are updated by the output compensation unit, the updated digital conversion parameters are stored in the non-volatile memory, and the last operation time is replaced with the present time data; and

if the determination is negative, the digital conversion parameters stored in the non-volatile memory are loaded in the image signal processing unit.

2. The document reading apparatus as claimed in claim 1, wherein

the energy-saving control unit includes a signal generating unit for generating a signal that indicates whether the operating voltage is output by the power supply unit because of external power being provided to the power supply unit, or because of mode switching from the pause mode to the waiting mode, and

the output compensation unit performs output compensation if the operating voltage is output by the power supply unit because of mode switching from the pause mode to the waiting mode.

3. The document reading apparatus as claimed in claim 1, wherein

the scanner includes a vertical scanning driving unit for driving the optical unit.

4. The document reading apparatus as claimed in claim 3, wherein

the scanner further includes a document width detection unit for detecting a width of the document based on the image signal when the optical unit is at a document width reading position.

5. The document reading apparatus as claimed in claim 4, wherein

the energy-saving control unit, when switching the power supply unit from the waiting mode to the pause mode, switches to the pause mode after the optical unit is positioned at the document width reading position.

6. The document reading apparatus as claimed in claim 4, wherein

the scanner includes a translucent plate for placing a document, a pressurizing member for pressing the document to the translucent plate, and a detecting unit for detecting a descending movement of the pressurizing member in a direction of the pressurizing member pressing the document, wherein

the document width detection unit detects the document width when the descending movement is detected.

7. The document reading apparatus as claimed in claim 6, wherein

the scanner further includes a detecting unit for detecting an ascending movement of the pressurizing member in a direction of the pressurizing member separating from the document, wherein the energy-saving control unit switches the power supply unit to the waiting mode when the unit for detecting the ascending movement in the direction of the pressurizing member separating from the document is detected.

8. The document reading apparatus as claimed in claim 4, wherein the vertical scanning driving unit

drives the optical unit to a vertical scanning starting position for document reading after determining the document width by the document width detection unit, and

when the optical unit arrives at a reference point sensor provided at a predetermined position in the direction of vertical scanning, vertical scanning position information of the optical unit is initialized with information representing the position of the reference point sensor in the direction of vertical scanning.

9. The document reading apparatus as claimed in claim 4, wherein

the energy-saving control unit puts the power supply unit in the waiting mode, when the external power is supplied to the power supply unit,

the vertical scanning driving unit drives the optical unit to the vertical scanning starting position for reading the document, and

when the optical unit arrives at a reference point sensor provided at a predetermined position in the direction of vertical scanning, vertical scanning position information of the optical unit is initialized with information representing the position of the reference point sensor in the direction of vertical scanning.

10. The document reading apparatus as claimed in claim 9, wherein

the control unit for controlling the output compensation drives the optical unit to a reference white plate reading position, and controls the output compensation after initialization of the vertical scanning position information.

11. The document reading apparatus as claimed in claim 4, wherein

the scanner further includes a translucent plate for placing the document and a detecting unit for detecting a descending movement of a pressurizing member for pressing the document onto the translucent plate in a direction of the pressurizing member pressing the document, and

the energy-saving control unit includes a detecting circuit for detecting switching between open and close states of the pressurizing member in the pause mode, wherein if switching is detected, the power supply unit is put in the waiting mode.

12. The document reading apparatus as claimed in claim 8, wherein

the reference point sensor is located between the vertical scanning starting position for reading the document by the optical unit and the document width reading position.

13. The document reading apparatus as claimed in claim 1, wherein

the reference white plate is located between the vertical scanning starting position for reading the document by the optical unit and the document width reading position.

14. The document reading apparatus as claimed in claim 4, further comprising:

a document conveyance unit for conveying the document in a direction that intersects an imaging scope of the optical unit at a sheet-through reading position in the direction of vertical scanning.

15. The document reading apparatus as claimed in claim 14, further comprising:

a translucent plate for placing a document, and a detector for detecting an opening state and a closing state of a pressurization member for pressing the document to the translucent plate; and

a document conveying unit that includes

a document tray;

a conveying unit for conveying the document in the document tray in the direction that intersects the imaging scope of the optical unit located at the sheet-through reading position; and

a document sensor for detecting the document in the document tray;

wherein

the vertical scanning unit drives the optical unit to the vertical scanning starting position for reading the document if an elapsed time from previous operation time is less than a predetermined value, if the translucent plate is closed, and if the document sensor detects the document, and

when the reference point sensor located at the predetermined position in the direction of vertical scanning detects arrival of the optical unit, the vertical scanning position information of the optical unit is initialized by the information that indicates the position of the reference point sensor in the direction of vertical scanning.

16. An image formation apparatus, comprising:

the document reading apparatus as claimed in claim 1;

a printer for printing an image expressed by image data on a recording medium;

an image data processing unit for converting the image data generated by the document reading apparatus into image data that are used by the printer;

an inputting unit for inputting operation directions to the document reading apparatus for reading the document and to the printer for printing; and

a controlling unit for controlling execution of document reading and printing in response to the operation directions that are input.

17. The image formation apparatus as claimed in claim 16, wherein

the printer is of an electrostatic latent image development method, wherein a toner image imprinted by a photo conductor on a recording medium is fixed by a fixing unit;

and

the power supply unit operates in a standby mode wherein power is provided to all loads, including the fixing unit of the image formation apparatus, in a low power mode wherein power is provided to all the loads except the fixing unit; and

in a pause mode wherein power is provided only to a unit for detecting a user operation of the image formation apparatus such that the mode can be shifted to the standby mode;

wherein the standby mode and the low power mode constitute the waiting mode.

18. The image formation apparatus as claimed in claim 17, further comprising:

a setting unit for setting a waiting time Td1 that is a time to wait for shifting to the low power mode from the standby mode, and a waiting time Td2 that is a time to wait for shifting to the pause mode from the low power mode, the waiting times Td1 and Td2 being stored in a memory;

wherein

the energy-saving control unit switches the power supply unit from the standby mode to the low power mode when there is no user operation for the waiting time Td1, and switches the power supply unit to the pause mode from the low power mode if there is no user operation in the low power mode for the waiting time Td2.

19. The image formation apparatus as claimed in claim 16, wherein

the printer is an ink jet printer that forms an image by injecting ink onto a recording medium, and

the power supply unit operates in a standby mode wherein power is provided to all the loads of the image formation apparatus, and in a pause mode wherein power is provided only to a unit for detecting a user operation of the image formation apparatus for shifting to the standby mode, wherein the standby mode is the waiting mode.

20. The image formation apparatus as claimed in claim 19, further comprising:

a setting unit for setting a waiting time Td1 that is a time to wait for shifting to the pause mode from the standby mode, and for storing the waiting time Td1 in a memory;

wherein

the energy-saving control unit switches the power supply unit from the standby mode to the pause mode if there is no user operation of the image formation apparatus for the waiting time Td1.