JP2003219127A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a resetting time without regulating an image reading condition at a reset time from an energy-saving mode. <P>SOLUTION: An image reading apparatus photoelectrically converts an original image by a reading unit having a CCD and an optical system mounted in a moving mechanism to enable setting of the image reading condition such as a black level and a white level or the like of the photoelectrically converted image signal. The apparatus comprises a means for setting the image reading condition at a transfer time to an energy-saving mode in a reading unit 1, and a means for preserving the set image reading condition. The apparatus sets the preserved image reading condition at the resetting time from the energy- saving mode, and read the image. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus used in an image forming apparatus such as a digital copying machine or a scanner apparatus having an energy saving mode, and the image forming apparatus equipped with the image reading apparatus.

[0002]

2. Description of the Related Art An image reading apparatus provided in a digital copying machine or the like reads C image information on an original surface to be read.
Read by CD. The CCD is provided with an optical system such as an original irradiation lamp and an optical lens so that an image on the original surface is imaged on the CCD light receiving portion. It is moved in the sub-scanning direction perpendicular to the scanning direction to read the image information on the document surface. Since the analog signal output from the CCD is weak as it is, it is amplified by the variable gain amplifier. The amplified analog signal is corrected for variations in CCD pixel sensitivity and light source illuminance distribution by shading data created based on the reference whiteboard and reference blackboard data that the CCD separately read during the scanning.

In a digital copying machine equipped with such an image reading device, when the use of the image reading device is temporarily interrupted from the end of a job to the start of the next job, the power of the image reading device is turned off. Some have an energy saving mode. At the time of returning from such an energy saving mode, the black level and white level adjustment sequence of the image reading apparatus is performed.

[0004]

However, in a digital copying machine or the like, it takes time to adjust each of the black level and the white level, and if the adjustment cannot be performed within a certain time, an initial setting value (default value) or The value adjusted normally at the previous adjustment was set and the adjustment sequence was terminated. This is because the device cannot shift to the operable state unless the adjustment is completed within a certain period of time, and the relationship between such time and the operation of the device is often set by regulation. Due to such a limitation of the return time based on the ZESM regulations, there may be a case where the time required for read readjustment of the reading unit when returning from the energy saving mode becomes a problem.

Further, the shading data has always disappeared when the power is cut off in the energy saving mode. Therefore, at the time of recovery, even if the reference whiteboard information could not be used in the control related to the white level before shutting off, it could not be used, and the information of the previous read adjustment value (white level setting value etc.) had to be substituted. . In addition, if the moving mechanism at the home position moves due to some impact or the like during the energy saving mode, a problem may occur.

The present invention has been made in view of the above-mentioned problems of the prior art. A first object of the present invention is to reduce the recovery time without re-adjusting the black level, the white level, etc. when returning from the energy saving mode. The second purpose is to make it possible to predict an inconvenience such as a position change of the moving mechanism that has occurred during the energy saving mode when returning from the energy saving mode.

[0007]

According to a first aspect of the present invention, an original image is photoelectrically converted by a reading unit including a CCD and an optical system mounted on a moving mechanism, and a black level and a white level of the photoelectrically converted image signal. In an image reading device that can set image reading conditions such as the following, it has a means for setting the image reading conditions at the time of transition to the energy saving mode and a means for saving the set image reading conditions. An image reading apparatus is characterized in that the image reading is performed by setting the image reading conditions.

According to a second aspect of the invention, in the image reading apparatus according to the first aspect, the means for setting the image reading condition at the time of shifting to the energy saving mode is an initial position of the moving mechanism,
An image reading apparatus characterized by setting a black level and a white level.

According to a third aspect of the present invention, an original image is photoelectrically converted by a reading section including a CCD and an optical system mounted on a moving mechanism, and image reading conditions such as a black level and a white level of the photoelectrically converted analog signal are set. In an image reading apparatus that sets and converts into a digital signal and corrects the digital signal with a shading value generated for each image reading, a means for saving the shading value of the final job when shifting to the energy saving mode, and an energy saving mode. When returning from, a means for comparing the stored shading value with the shading value of the job generated at the time of returning is provided, and when the difference exceeds a predetermined value, the image reading condition is set and the image reading of the job is performed. If the difference does not exceed the predetermined value, the image of the job is read without making the settings. An image reading apparatus according to claim.

A fourth aspect of the present invention is an image forming apparatus including the image reading apparatus according to any one of the first to third aspects.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to FIGS.
Will be described with reference to. FIG. 1 is a block diagram of a main part of an image reading apparatus according to an embodiment of the present invention. In the figure, a reading unit 1 processes a CCD 11 having 2-channel outputs of even-numbered pixels and odd-numbered pixels, and processes the outputs. An analog processing circuit (system 1) 121 and an analog processing circuit (system 2) 122, an AD converter (system 1) 131 and an AD converter (system 2) 132, and a timing generation circuit configured by a clamp circuit, a gain correction circuit, and the like. 14, a DA converter 15, a driver 16 and the like.

The analog processing circuits 121, 122,
The AD converters 131 and 132 are composed of two systems, but this corresponds to the two-output type of the CCD 11, and as a matter of course, when the CCD 11 is composed of one-channel output or four-channel output. Will be configured accordingly.

The control unit 2 is a unit for controlling the image forming apparatus, and comprises a CPU 23, a ROM, a RAM, a memory 22 such as a non-volatile memory, and the like.

The analog processing circuits 121 and 122 are
The black level and the white level are adjusted by changing the clamp level and the gain of the read level such as the black level and the white level via the timing generation circuit 14, the DA converter 15, and the driver 16 according to the instruction of the CPU 23 of the control unit 2. To do. The analog processing output whose black level and white level are adjusted in this way is the AD converter 131, 1
It is converted into a digital output at 32 and output to the image processing unit 3 as digital image data.

Under the command of the control unit 2, the image processing unit 3 subjects the digital image data to data sampling, shading processing, gamma correction processing, scaling processing, and filter processing necessary for adjustment, and it will be described later. Perform shading data comparison processing. Particularly in the shading process, white information on the reference white plate is averaged in the sub-scanning direction (original conveyance direction) for each pixel arranged in the main scanning line direction of the CCD, and finally an average value for each main scanning pixel is calculated. To generate shading data. The processed digital image data is output to a plotter unit (not shown) to form an image.

The image reading apparatus having the above structure has an energy saving mode. If the user selects this mode from the input means (not shown), when one job ends and a certain waiting time elapses, the mode shifts to an energy saving mode in which the power of all or a specific device of the image reading device is shut off. . The condition at the time of shifting to the energy-saving mode is that there is no job and there is a standby state for a certain period of time, and this time constraint is smaller than when the image reading device is started at the time of restoration.

Therefore, according to an embodiment of the present invention, during the standby time before the shift to the energy saving mode, the sequence that was conventionally executed at the time of returning from the energy saving mode is performed to adjust the adjustment data such as the black level and the white level. The feature is that the image is read by saving and setting the saved data when returning. When a certain job is completed in the image reading apparatus, the CPU 23 of the control unit 2 instructs the homing of the moving mechanism (carriage), the adjustment of the black level, and the adjustment of the white level at a predetermined timing. In accordance with this instruction, the control unit (not shown) of the reading unit 1 adjusts the homing of the moving mechanism (carriage), the black level, and the white level, and stores the adjustment values in the nonvolatile memory of the memory 22. FIG. 2 is a diagram showing an example of the sequence. To explain with reference to FIG. 2, the power of the reading unit 1 is turned on (S11) at the time of shifting to the energy saving mode, and the home position of the moving mechanism is initialized. (S12), the lamp for illuminating the original is turned on (S13). Then, if the CCD is of a type having two outputs and is composed of two systems of analog processing circuits 121 (system 1) and 122 (system 2), the black level of system 1 (S14), system 2 Black level (S15), white level of system 1 (S16), system 2
Adjust each white level (S17) of
Then, the lamp is turned off (S18), and the adjustment data is stored in the nonvolatile memory of the memory 22 (S19). afterwards,
Switch to energy saving mode. Then, when returning from the energy saving mode by the next job, the black level and the white level of the analog processing circuits 121 and 122 are adjusted by the adjustment data stored in the nonvolatile memory, and the image is displayed at the home position of the initially set moving mechanism. Start reading.

According to this embodiment, homing / initial setting, black level adjustment (systems 1 and 2), and white level adjustment (systems 1 and 2) are performed during the standby time before shifting to the energy saving mode, and the adjustment is performed. Since the value is saved, the latest adjustment data will be saved. In the image reading device, the latest adjustment data is set at the time of returning from the energy saving mode, and the image is read by the data. Therefore, it is possible to reduce the recovery time and generate image data that enables copying of high-quality images.

Next, another embodiment of the present invention will be described.
The shading data is data for reading the reference white plate and correcting the variations in the sensitivity of each read pixel and the variations in the illuminance distribution of the light source. The shading data is generated at the time of reading the original and is updated every scan of the original or every fixed scan. ,
It is what is retained. Then, this update is generally not updated at the end of document reading, but is generally reset when new shading data is taken in. In this way, the shading data is held until immediately before the shift to the energy saving mode. However, in the conventional image reading apparatus, the shading data disappears when the power is cut off after shifting to the energy saving mode, and the shading data does not exist until newly created by the scan after the return. .

Therefore, according to another embodiment of the present invention, the shading data generated in the last document reading is stored during the waiting time until the shift to the energy-saving mode, and this data is used for predicting the abnormality occurrence of the device at the time of restoration. It is characterized by

FIG. 3 is a flow chart of a process of saving the shading data when shifting to the energy saving mode. The process will be described with reference to FIG. When the image is read in the energy-saving mode, the shading data is updated for each document scan (S21), and the updated shading data is further updated by the document scan of the final job immediately before shifting to the energy-saving mode (S22). When there are no more jobs, the control unit (not shown) of the reading unit 1 enters the standby state immediately before shifting to the energy-saving mode (S23). ), The power saving mode is entered (S25), and the power of the image reading apparatus is cut off (S26).

According to the present embodiment, the shading data, which has been conventionally allowed to disappear when the power is cut off,
Since it is saved even after the power is cut off, it is retained until the power is returned from the energy saving mode. Therefore, when returning from the energy saving mode, it is possible to predict the occurrence of an abnormality in the device by reading this data for comparing the states of the device.

Still another embodiment will be described. Even when saving the shading data, the adjustment data such as white level and black level is saved when shifting to the energy saving mode, and the saved adjustment data such as white level and black level is set when returning from the energy saving mode and energy mode. This is effective for shortening the recovery time. However, as a state of concern, there is a possibility that the read original data may be affected in the event of some abnormality, such as a shock to the machine or damage to the element, during the energy saving mode.
If the carriage position changes due to impact or the like, if it is operated as it is, the carriage may move too far and may collide with the housing and be damaged.

Therefore, according to still another embodiment of the present invention, the shading data of the final job is saved at the time of shifting to the energy saving mode, and the saved shading data is obtained for updating at the time of returning from the energy saving mode. , And when the difference is significant,
It is characterized in that the black level and the white level are readjusted.
FIG. 4 is a flowchart of the image reading operation when the shading data is saved. In the figure, the image reading apparatus is in the energy saving mode (S31), and upon receiving a return command from the energy saving mode (S32), the memory 2
The shading data stored in the non-volatile memory 2 is called and the adjustment data also stored is set (S33). Then, document scanning is started (S34), and shading data for updating is first generated (S35). The generated shading data and the called shading data are compared by a comparison circuit (not shown) of the image processing unit 3 (S36), and it is checked whether or not a predetermined value is exceeded (whether or not there is a significant difference). (S37). Therefore, for shading data called by the image processing IC (not shown) of the image processing unit 3, the average value and peak value (Ma) of all pixel data are obtained.
The x value) and the bottom value (Min value) are calculated. Similarly, for shading data generated for updating, the average value, peak value (Max value), and bottom value (Min value) of all pixel data are calculated. Then, the difference is obtained and compared with a predetermined value. As a result of the comparison, if the predetermined value is not exceeded (S37, NO), the document scan is continued (S3).
8) The operation is finished. If it exceeds the predetermined value (S37, YES), the document scanning is stopped (S3).
9). At this time, the user cannot obtain the original quick recovery time, and therefore displays or announces "Initialization due to an error. Please wait for a while." Next, the process proceeds to step 40, where the homing / initial setting, black level adjustment (system 1 and system 2), white level adjustment (system 1 and system 2) described in FIG. .

The calculation of the average value, the peak value (Max value), and the bottom value (Min value) of all pixel data relating to the shading data depends on the capability of the reading system, and when the load is high, the shading data of a specific pixel is calculated. Alternatively, if the load is low, all pixel data may be used as is.

According to the present embodiment, the recovery time from the energy saving mode can be reduced even in the case of an abnormal situation such as an impact on the machine, a damage of the element, or a change in the carriage position due to the impact, which may occur during the energy saving mode. The image reading device can be normally operated while being shortened.

[0027]

Effects of the invention according to claims 1 and 2 are as follows:
It is possible to shorten the return time when returning from the energy-saving mode, and it is possible to perform image reading under the latest, that is, highly accurate image reading conditions. Effect corresponding to the invention of claim 3: By comparing the shading data before and after shifting to the energy-saving mode, when it is predicted that an abnormal situation occurs during the energy-saving mode, the image reading condition is reset, so the energy-saving mode is set. It is possible to shorten the recovery time from, and to ensure the normal operation of the image reading apparatus. Effects corresponding to the invention of claim 4 In an image forming apparatus such as a digital copying machine or a facsimile equipped with the image reading device of claims 1 to 3, image formation is achieved by realizing the effects corresponding to the above inventions. The performance of the device can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of an image reading apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing an adjustment sequence according to the embodiment of the present invention.

FIG. 3 is a flowchart of a process of saving shading data when shifting to the energy saving mode according to the embodiment of the present invention.

FIG. 4 is a flowchart of an image reading operation when shading data according to the embodiment of the present invention is saved.

[Explanation of symbols]

1 ... Reading unit, 2 ... Control unit, 3 ...
Image processing unit, 11 ... CCD, 121 ... Analog processing circuit, 131 ... AD converter, 14 ... Timing generation circuit, 15 ... DA converter, 16 ... ··driver

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5B047 AA01 BB02 BC14 CB02 CB22                       DA04 DC06                 5C072 AA01 BA03 EA05 FB12 RA16                       UA02 XA01                 5C077 LL04 MP01 PP06 PP47 PQ08                       PQ12 PQ20 PQ23 SS01 TT06

Claims (4)

[Claims] 1. An image reading method in which an original image is photoelectrically converted by a reading unit composed of a CCD and an optical system mounted on a moving mechanism, and image reading conditions such as a black level and a white level of the photoelectrically converted image signal can be set. The device is equipped with a means for setting the image reading conditions when shifting to the energy saving mode and a means for saving the set image reading conditions.When returning from the energy saving mode, the saved image reading conditions are set and the image reading is performed. An image reading device characterized by performing. 2. The image reading apparatus according to claim 1,
The image reading device, wherein the means for setting the image reading condition at the time of shifting to the energy saving mode sets an initial position of the moving mechanism and a black level and a white level. 3. An original image is photoelectrically converted by a reading section including a CCD and an optical system mounted on a moving mechanism, and image reading conditions such as a black level and a white level of the photoelectrically converted analog signal are set to obtain a digital signal. An image reading apparatus that converts the digital signal to a shading value generated for each image reading and stores the shading value of the final job at the time of transition to the energy saving mode;
When returning from the energy saving mode, a means for comparing the stored shading value with the shading value of the job generated at the time of returning is provided. When the difference exceeds a predetermined value, the image reading condition is set and the job An image reading apparatus, which reads an image, and when the difference does not exceed a predetermined value, reads the image of the job without performing the setting. 4. An image forming apparatus comprising the image reading device according to claim 1. Description: