JP3564025B2 - Image processing apparatus and control method of the image processing apparatus - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image processing apparatus and a control method of the image processing apparatus, and more particularly, to an image processing apparatus having a function of reading image data and a control method thereof.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an image processing apparatus that performs image data reading processing using a light emitting diode (hereinafter, referred to as “LED”), all outputs from an LED are monitored by a reading sensor regardless of the sheet size of a document sheet. The image data reading process is performed by performing a correction to obtain an appropriate amount of light by changing the LED lighting time and the current value.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional image processing apparatus, since the light amount is corrected for the entire area (maximum sheet size) detected by the reading sensor, the light amount is adjusted in consideration of a part that is not actually required as read data. Therefore, even when the light amount varies depending on the reading position of the reading sensor, the light amount is adjusted so that the output of the effective image portion is reduced, and the S / N ratio is reduced.
[0004]
SUMMARY An advantage of some aspects of the invention is to provide an image processing apparatus capable of performing optimal light amount adjustment in accordance with the size of a document and a method of controlling the image processing apparatus. And
[0005]
[Means for Solving the Problems]
In order to achieve the above object, an image processing apparatus according to claim 1 includes at least one or more light sources for irradiating a document, reading means for reading the document, and outputting an image signal, and reading the document. prior to Said The light source is turned on to irradiate the reference member, and the reading unit reads the reference member. By doing Detects light amount overflow in the effective image range from the obtained image signal Light intensity Detecting means; Light intensity When the light amount overflow is detected by the detecting means, In the effective image range Adjusting means for adjusting the drive current and / or the lighting time of the light source so that overflow does not occur; Shading correction means for performing shading correction on an image signal obtained by reading the document by the reading means, The adjusting means After adjusting the drive current and / or the lighting time of the light source so that overflow does not occur in the effective image range, the shading correction is performed by causing the reading unit to read the reference member with the light source turned on. Control is performed to obtain the shading correction data for Control means, wherein the adjustment means performs the adjustment of the drive current with higher priority than the adjustment of the lighting time.
An image processing apparatus according to a second aspect of the present invention is the image processing apparatus according to the first aspect, wherein the reference member is white.
An image processing apparatus according to a third aspect of the present invention is the image processing apparatus according to the first aspect, wherein the effective reading range is based on a document sheet size.
An image processing apparatus according to a fourth aspect of the present invention is the image processing apparatus according to any one of the first to third aspects, wherein the adjusting unit determines whether the driving current value is larger than a predetermined current value. It is characterized in that, when an overflow of the light amount is detected, the drive current value is gradually decreased by a predetermined minute current value until the drive current value reaches the lower limit current value.
An image processing apparatus according to a fifth aspect of the present invention is the image processing apparatus according to the fourth aspect, wherein the adjusting unit is configured to detect an overflow of the light amount even when the drive current value reaches the lower limit current value. The lighting time is gradually reduced by a predetermined minute lighting time.
An image processing apparatus according to a sixth aspect of the present invention is the image processing apparatus according to any one of the first to fifth aspects, wherein the light source includes a light source of a plurality of colors including light emitting diodes, and the control unit includes: It is characterized in that when the lighting of each light source is time-divisionally performed on a line-by-line basis by the reading means and sequentially turned on, the light amount of each light source is controlled independently.
An image processing apparatus according to a seventh aspect of the present invention is the image processing apparatus according to the sixth aspect, wherein the plurality of light sources are a red light source, a green light source, and a blue light source.
An image processing apparatus according to an eighth aspect of the present invention is the image processing apparatus according to the seventh aspect, wherein when reading monochrome image data, the image data reading operation is performed using a green light source among the light sources of the plurality of colors. It is characterized by performing.
[0006]
In order to achieve the above object, a control method of an image processing apparatus according to a ninth aspect of the present invention includes: Small At least one light source Irradiates the original with the reading means, and Scan the original By doing A reading step of outputting an image signal; and Said Turn on the light source, illuminate the reference member, and read the means Reads the reference member By doing Detects light amount overflow in the effective image range from the obtained image signal Light intensity The detecting step; Light intensity In the detection step In If an overflow of the light amount is detected, In the effective image range Adjusting the drive current and / or lighting time of the light source so that overflow does not occur; A shading correction step of performing shading correction on the image signal obtained by reading the document in the reading step; The adjusting step After adjusting the drive current and / or the lighting time of the light source so that overflow does not occur in the effective image range, the shading correction is performed by causing the reading unit to read the reference member with the light source turned on. Control is performed so that the reading process of the document in the reading step is executed. And a control step, wherein the adjustment step performs the adjustment of the drive current with higher priority than the adjustment of the lighting time.
According to a tenth aspect of the present invention, in the control method of the ninth aspect, the reference member is white.
An image processing apparatus control method according to an eleventh aspect of the present invention is the image processing apparatus control method according to the ninth aspect, wherein the effective reading range is based on a document sheet size.
A control method of an image processing apparatus according to a twelfth aspect of the present invention is the control method of the image processing apparatus according to any one of the ninth to eleventh aspects, wherein the adjusting step is such that the driving current value is higher than a predetermined current value. Is determined, and when the light amount overflow is detected, the drive current value is gradually reduced by a predetermined minute current value until the drive current value reaches the lower limit current value.
In a control method of an image processing apparatus according to a thirteenth aspect of the present invention, in the control method of the image processing apparatus according to the twelfth aspect, the adjusting step includes the step of causing the light amount overflow even if the drive current value reaches the lower limit current value. When the detection is detected, the lighting time is gradually reduced by a predetermined minute lighting time.
According to a fourteenth aspect of the present invention, in the control method of the image processing apparatus according to any one of the ninth to thirteenth aspects, the light source includes a light source of a plurality of colors including light emitting diodes. The control step is characterized in that, when the lighting of each light source is time-divisionally performed on a line-by-line basis in the reading step and sequentially turned on, the light amount of each light source is controlled independently.
A control method for an image processing apparatus according to a fifteenth aspect of the present invention is the control method for an image processing apparatus according to the fourteenth aspect, wherein the plurality of light sources are a red light source, a green light source, and a blue light source.
In a control method of an image processing apparatus according to a sixteenth aspect of the present invention, in the control method of the image processing apparatus according to the fifteenth aspect, when reading monochrome image data, a green light source is used among the light sources of the plurality of colors. A reading operation of image data is performed.
[0007]
Other features of the present invention will become apparent from the following description of embodiments of the present invention.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0009]
FIG. 1 is a system configuration diagram showing an embodiment of an image processing apparatus according to the present invention. The image processing apparatus includes a ROM 1 storing a predetermined program such as a control program for performing image processing; An SRAM 2 that stores transmission source information, user registration information, and the like and is used as a work area, a modem 3 that performs predetermined modulation / demodulation processing on image signals and audio signals, and various images that will be described later for read image data. An image processing unit 4 that performs processing, an image forming processing unit 5 that performs various functions for forming image data on recording paper, and a CPU 6 that controls the entire apparatus are connected via a bus 7.
[0010]
A line feed motor 8 for transporting recording paper in the sub-scanning direction is connected to the CPU 6 via a motor driver 9. Further, a carriage motor 10 for driving a carriage on which a printer head described later is mounted is connected to a motor. It is connected via a driver 11.
[0011]
The image processing unit 4 has a reading sensor 12 for reading image data line by line in 8 pels in the main scanning direction and a light source unit (hereinafter, referred to as “LED light source”) 13 composed of LEDs, which is detachably mounted. I have. The LED light source 13 has a red (R) light source 14, a green (G) light source 15, and a blue (B) light source 16. The LED light source 13 can reduce the size of the device as compared with the case where a light source such as a fluorescent lamp is used, and has a stable light amount and a quick response characteristic, so that the light source can be rapidly switched. Therefore, there is an advantage that image formation can be performed at a high speed by a sheet through type.
[0012]
Further, a movement detection sensor 17 is connected to the image processing unit 4. That is, in the present embodiment, the reading sensor 12 and the LED light source 13 are detachable as described above, and the reading sensor 12 and the LED light source 13 are detached from the image processing unit 4 and are separated by a hand scanner (not shown). An image document such as a cardboard or a book can be read. In this case, the movement detection sensor 17 detects a movement state of the hand scanner and generates a trigger for starting image processing.
[0013]
The image forming processing unit 5 includes an operation unit 18 including a keyboard for inputting predetermined control information and the like, a liquid crystal display panel (LCD) for displaying status information and the like of the apparatus, and a printer head for recording image data. 19, a DRAM 20 for temporarily storing image data supplied to the printer head 19, a cartridge sensor 21 for detecting the presence or absence of a print cartridge and the type of the cartridge, An original detection sensor 22 for detecting the original and a paper detection sensor 23 for detecting the paper size of the recording paper and the presence / absence of the recording paper are connected. Further, a transport motor 24 for transporting the original is provided to the image forming processing unit 5 by a motor driver 25. Connected through.
[0014]
In the present embodiment, the printer head 19 is of an ink jet type having an ink cartridge containing an ink tank, and a plurality of nozzles are juxtaposed in the sub-scanning direction to form a head recording surface. Then, during the recording operation, the carriage on which the printer head 19 is mounted reciprocates in the main scanning direction orthogonal to the nozzle arrangement direction, whereby an image is formed in an area on the recording paper corresponding to the recording width of the plurality of nozzles. An image is formed on the recording sheet by conveying the recording sheet by the recording width in the sub-scanning direction and repeating the above-described recording operation.
[0015]
The printer head 19 can be replaced with a color printer head capable of recording in a color copy mode and a monochrome printer head capable of recording in a monochrome copy mode.
[0016]
In this embodiment, the ink jet type printer head 19 is used as described above, but a thermal transfer type printer head 19 may be used.
[0017]
The keyboard of the operation unit 18 has a color copy key for reading a document image in color and instructing recording in color, and a monochrome copy key for reading in monochrome and instructing recording in monochrome. By operating the copy key, an image can be formed in the color copy mode or the monochrome copy mode, respectively.
[0018]
The image forming processing unit 5 converts the image data arranged in the main scanning direction into image data arranged in the sub-scanning direction in accordance with the arrangement of the nozzles of the printer head 19 and transfers the image data to the printer head 19. It converts input data input from the keyboard of the unit 18 and output signals of various sensors into code signals that can be discriminated by the CPU 6, or controls the drive timing of the transport motor.
[0019]
A network control unit (hereinafter, referred to as “NCU”) 26 is connected to the modem 3, and a wired telephone 27 is connected to a public telephone line 28 via the NCU 26. Further, a wired telephone 27, a base unit 29 of a wireless telephone, and a speaker 30 for transmitting status information and the like of the image processing apparatus to a user by voice are connected to a cross point 31. The unit 29, the speaker 30, and the NCU 26 are selectively connected. Incidentally, 32 is a wireless slave unit.
[0020]
FIG. 2 is a block diagram showing details of the image processing unit 4. As shown in FIG.
[0021]
In the figure, an analog image signal read by a reading sensor 12 is converted into a 10-bit digital image signal by an A / D conversion circuit 31. The peak detection circuit 32 detects the digital image signal output from the A / D conversion circuit 31, and the AGC circuit 33 detects the digital image signal (luminance signal) of 10 bits output from the A / D conversion circuit 31. The optimum 8-bit image signal (luminance signal) is selected based on the output of the peak detection circuit 32, and the selected image signal is input to the shading / black correction circuit 34.
[0022]
Then, the shading / black correction circuit 34 performs shading correction and black correction based on the correction data stored in the correction data storage unit 35. That is, the correction data storage unit 35 stores the correction data obtained by the shading / black correction circuit 34, and the shading / black correction circuit 34 performs shading correction and black correction of the image data based on the stored correction data. .
[0023]
The R, G, and B image signals corrected by the shading / black correction circuit 34 are converted into Y (yellow), M (magenta), C (cyan), and K (black) image signals by the color conversion circuit 36. Then, the resolution conversion circuit 37 converts the image of 8 pel in the main scanning direction read by the reading sensor 12 into the resolution of the printer, for example, 360 dpi, reduces the size of the read image data, and converts unnecessary images. Mask it.
[0024]
Next, the binarization processing circuit 38 binarizes the multi-level data from the resolution conversion circuit 37 and stores it in an output register 39 connected to the bus 7.
[0025]
The light amount overflow detection circuit 40 monitors the overflow signal of the A / D conversion circuit 31 and the effective image processing range during the effective image period, and the sensor output within the effective image processing range causes the A / D conversion circuit to detect an excessive light amount. It is detected whether or not the input voltage range exceeds the input voltage range. Specifically, an overflow status signal (OVFL) is output from the A / D conversion circuit 31 to the light amount overflow detection circuit 40, and when an analog signal that is equal to or larger than the input range of the A / D conversion circuit 31 is input, the H level is output. Is output, and the light amount overflow detection circuit 40 detects that the input voltage range of the A / D conversion circuit 31 is exceeded.
[0026]
In addition to the output register 39 described above, a lighting mode setting register 41, an overflow register 42, a lighting time / current setting register 43, and a reduction ratio / mask area setting register 44 are connected to the bus 7.
[0027]
The lighting mode setting register 41 sets a current value for controlling the light amount of the LED light source 13 and a lighting mode for controlling the light source control circuit 47, and furthermore, sets any one of the LED light sources 13 in each mode. Set whether to turn on the light source. The overflow register 42 is connected to the bus 7 so that the light amount overflow can be detected from the CPU 6, and the lighting time / current setting register 43 enables the lighting time / current of the LED light source 13 to be set from the CPU 6. The reduction rate / mask area setting register 44 is connected to the bus 7 so that the CPU 6 can set a mask area and a reduction rate of image data. The designation of the effective image period is also performed by the reduction ratio / mask area setting register 44.
[0028]
Further, the pixel counter 45 transmits a signal for specifying an effective image range to the light amount overflow detection circuit 40 based on the count of input pixels and the set value of the reduction ratio / mask area setting register 44.
[0029]
Further, the light source control circuit 47 is supplied with a light source switching clock 48 and a reading trigger 49 from the CPU 6.
[0030]
The light source switching clock 48 is a clock for switching lighting of the light source. In the case of color reading, a clock is input to the light source control circuit 47 every 2.5 msec. Every time is input, the LED light source 13 is switched on and off in order of the R light source 14, the G light source 15, and the B light source 16 to be turned on. On the other hand, in the case of monochrome reading, a light source switching clock 48 is input every 2.5 msec, and in this case, only the G light source 14 is turned on for a necessary time. The reading trigger 49 is issued for each line, and the image processing unit 4 is activated by the reading trigger.
[0031]
Switching between color reading and monochrome reading is set by the lighting mode setting register 41.
[0032]
As described above, the light source control circuit 47 performs lighting control such as switching of the LED light source 13 in synchronization with the input light source switching clock 48 in accordance with the setting contents of the lighting mode setting register 41 and the lighting time / current setting register 43. At the same time, the reading operation is started in accordance with the input reading trigger 49 or a signal change of the movement detection sensor 17.
[0033]
The output signal from the light source control circuit 47 is supplied to a lighting current control circuit 46, which controls the lighting of the LED light source 13.
[0034]
Then, three signal lines 50 are output from the light source control circuit 47, and the AGC circuit 33 and the shading / black correction circuit 34 determine which of the R light source 14, the G light source 15, and the B light source 16 is to be turned on. , The color conversion circuit 36, the resolution conversion circuit 37, and the output register 39, and the AGC circuit 33, the shading / black correction circuit 34, the color conversion circuit 36, the resolution conversion circuit 37, and the output register 39 are turned on. Various processes can be performed based on the color of the light source.
[0035]
FIG. 3 is a flowchart showing a procedure for reading image data. This program is executed by the CPU 6.
[0036]
In step S1, it is determined whether the copy mode is set to the monochrome copy mode from the input state of the keyboard of the operation unit 18. If it is determined that the monochrome copy mode has not been set, the process proceeds to step S2, and it is determined whether the color copy mode has been set. When the answer is negative (No), the process returns to step S1 to repeat the above-described determination processing. On the other hand, when the answer is affirmative (Yes), the process proceeds to step S3 to determine whether the original is set on the original platen. Is determined based on a signal from the document detection sensor 22. If the answer is negative (No), "Please set original" is displayed on the LCD of the operation unit 18 (step S4), and the process returns to step S1 while the answer to step S3 is affirmative (Yes). In this case, the process proceeds to step S5 to determine whether or not there is a recording sheet based on a signal from the sheet detection sensor 23. If the answer is negative (No), "Please set paper" is displayed on the LCD of the operation unit 18 (step S6), and the process returns to step S1 while the answer to step S5 is affirmative (Yes). In this case, the process proceeds to step S7, and it is determined whether or not a cartridge is mounted based on a signal from the cartridge sensor 21. If the answer is negative (No), "Please set the cartridge" is displayed on the LCD of the operation unit 18 (step S8), and the process returns to step S1 while the answer to step S7 is affirmative (Yes). In this case, the process proceeds to step S9, and it is determined whether or not a color cartridge is mounted based on a signal from the cartridge sensor 21. If the answer is negative (No), "Please set the color cartridge" is displayed on the LCD of the operation unit 18 (step S10), and the process returns to step S1, while the answer in step S9 is affirmative (Yes). In step S11, the process proceeds to step S11, where the sheet width of the recording sheet is detected by the sheet detection sensor 23, and in step S12, the size width of the document sheet is detected by the document detection sensor 22, and thereafter, a prescan process described later is performed. (Step S13).
[0037]
Next, the reading width of the recording paper to be read is set (step S14), the color reading process is started (step S15), and after the color recording process is performed (step S16), the program ends.
[0038]
On the other hand, if the answer to step S1 is affirmative (Yes), that is, if the monochrome copy mode is set, the process proceeds to step S17 to determine whether or not the original is set on the original platen based on the signal from the original detection sensor 22. If the answer is negative (No), "Please set original" is displayed on the LCD of the operation unit 18 (step S18), and the process returns to step S1 while the answer to step S17 is affirmative (Yes). In the case of ()), the process proceeds to step S19, and it is determined whether or not there is a recording sheet based on a signal from the sheet detection sensor 23. If the answer is negative (No), "Please set paper" is displayed on the LCD of the operation unit 18 (step S20), and the process returns to step S1 while the answer to step S19 is affirmative (Yes). In this case, the process proceeds to step S21, and it is determined whether or not a cartridge is mounted based on a signal from the cartridge sensor 21. If the answer is negative (No), a message "Please set the cartridge" is displayed on the LCD of the operation unit 18 (step S22), and the process returns to step S1, while the answer to step S21 is affirmative (Yes). In this case, the process proceeds to step S23, in which the sheet width of the recording sheet is detected by the sheet detection sensor 23, and in step S24, the document width of the document sheet is detected by the document detection sensor 22, and thereafter, a prescan process described later is performed ( Step S25).
[0039]
Next, the mask area reduction ratio is set (step S26), the monochrome reading process is started (step S27), and the monochrome recording process is performed (step S28), followed by terminating the present program.
[0040]
FIG. 4 is a flowchart of the prescan processing routine executed in step S13 or S25.
[0041]
First, in step S31, it is determined whether the copy mode is set to the color copy mode based on the operation status of the keyboard of the operation unit 18. If the answer is affirmative (Yes), that is, if the color copy mode has been set, the process proceeds to step S32, where the lighting time is initialized according to the color copy mode. That is, the setting is made such that the time division switching of the three color light sources is enabled, and the lighting time is set in the lighting time / current setting register 43 so that each of the colors of the LED light source 13 is illuminated with a predetermined maximum lighting time. I do. Specifically, in the present embodiment, the predetermined maximum lighting time is set to, for example, 2.5 msec for each of the light sources 14 to 16.
[0042]
Next, in step S33, the maximum drive current value at the time of color copying is set as the current initial value in the lighting current control circuit 46, and the light source control circuit 47 turns on the R, G, and B light sources in the lighting mode setting register 41. Set to let. In the present embodiment, the predetermined maximum lighting time is set to 2.5 msec for each of the light sources 14 to 16 as described above. Therefore, a color image is read at 7.5 msec per line. That is, a color image is read three times by switching the R light source 14, the G light source 15, and the B light source 16 in a time-division manner at a cycle of 2.5 msec. Since the lighting time of each of the light sources 14 to 16 is switched in a time-division manner as described above, the lighting duty ratio for one color is up to 33%. Even if the amount of light is increased by increasing the current supplied in the mode, the LED does not deteriorate. Accordingly, the maximum drive current value as the initial value is set in the lighting mode setting register 41 at twice the current value, for example, 30 mA as compared with the case of the monochrome copy mode.
[0043]
Next, in step S34, a reading process based on white is performed. That is, the reading trigger 49 is supplied from the CPU 6 to the light source control circuit 47, whereby the R light source 14 is turned on at the maximum driving current value (30 mA) for the maximum lighting time (2.5 msec), and the light from the R light source 14 is emitted. Illuminates a white plate (not shown), and the reflected light is received by the reading sensor 12. The received light is photoelectrically converted in the reading sensor 12 and is converted into a digital signal by the A / D conversion circuit 31. In step S35, the light amount overflow detection circuit 40 determines whether or not the digital signal has overflowed. When the answer is negative (No), the process proceeds to step S41. On the other hand, when the answer is affirmative (Yes), that is, when it is determined that the light amount overflow is detected, the current value is reduced to the predetermined lower limit value (step S36). For example, it is determined whether it is 20 mA) or less. If the answer is negative (No), that is, if the answer is larger than the predetermined lower limit, the current value of the R light source 14 is set to a value obtained by subtracting a predetermined amount (for example, 5 mA) from the current value, and the process returns to step S34. The above processing is repeated.
[0044]
Note that the predetermined lower limit is such that the emission wavelength distribution of the LED light source 13 changes depending on the drive current, and the variation of the emission wavelength distribution tends to increase on the low current side. Therefore, it is set larger than the monochrome copy mode.
[0045]
When the answer to step S35 is negative (No), that is, when it is determined that the overflow of the light amount is no longer detected, the current value at that time is set in the lighting time / current setting register 43 as the driving current of the R light source 14, Proceed to step S41.
[0046]
On the other hand, if the answer to step S36 is affirmative (Yes), that is, if the light amount overflows even if the current value reaches the predetermined lower limit value, the process proceeds to step S38, and the lighting time is changed from the maximum lighting time to the predetermined time ( For example, the value is set to a value obtained by subtracting 2.5 / 16 msec), and the lighting time is shortened. White The reference plate is read, and the light amount overflow detection circuit 40 detects that the light amount is over. ー It is determined whether a flow has been detected. When the answer is affirmative (Yes), the process returns to step S38 to repeat the above-described processing. On the other hand, when the answer in step S40 is negative (No), that is, when it is determined that the light amount overflow is no longer detected, the process returns to step S38. The lighting time of the R light source 14 at that time is set in the lighting time / current setting register 43.
[0047]
The above processing is performed for the G light source 15 and the B light source 16 in addition to the R light source 14, and the current value or the lighting time at which the light amount does not overflow is set in the lighting time / current setting register 43.
[0048]
When the adjustment of the current value and the lighting time of the LED light source 13 is completed in this way, the process proceeds to step S41, where the CPU 6 turns off all the light sources of the LED light source 13, and in the subsequent step S42, the shading / black correction circuit 34 A black correction is instructed, and the shading / black correction circuit 34 corrects a variation in dark output of each pixel of the reading sensor 12 to perform black correction. Then, in step S43, after the black correction data is stored in the correction data storage unit 35, the LED light source 13 is turned on again. In step S44, the shading / black correction circuit 34 reads its own plate (not shown) and The shading correction data for all the LED light sources 13 is obtained by correcting the variation of the bright output for each pixel, and the process returns to the main routine (FIG. 3).
[0049]
On the other hand, when the answer to step S31 is negative (No), that is, when the monochrome copy mode is set, the current value and the lighting time of the G light source 15 are adjusted as described above.
[0050]
That is, in step S45, 2.5 msec full lighting is set in the lighting time / current setting register 34 in order to read a monochrome image at 2.5 msec per line, and in subsequent step S46, the current value is initialized in monochrome copying. That is, the maximum drive current value is set. The maximum drive current value of the G light source 15 is smaller than the maximum drive current value in the color copy mode, and is set to, for example, （(15 mA) of the maximum drive current value in the color copy mode. This is because, as described above, in the color copy mode, lighting is performed at a duty ratio of at most 33%, whereas in the monochrome copy mode, lighting is performed at a duty ratio of 100%, and lighting is performed at a duty ratio of 100%. This is because the range in which the LED light source 13 does not deteriorate is used as the drive current.
[0051]
After the initial setting of the lighting time and the current value as described above, the processes after step S34 are performed as in the color copy mode.
[0052]
That is, until the light amount does not overflow in steps S34 to S37 or the current value reaches a predetermined lower limit, the drive current is adjusted by subtracting a predetermined amount (for example, 2.5 mA), and the current value is reduced. If the light amount has overflowed after reaching the predetermined lower limit value, the lighting time is reduced and the lighting time is adjusted in steps S38 to S40 until the light amount does not overflow.
[0053]
The predetermined lower limit of the current value is set lower than that in the color copy mode, and is set to, for example, 5 mA. This is because deterioration of the G light source 15 caused by flowing a large current through the G light source 15 is suppressed as much as possible, and the influence of a change in the LED emission wavelength due to a change in the current is smaller than in the case of color copying.
[0054]
Then, in step S41, the CPU 6 turns off all the light sources of the LED light sources 13, and in subsequent step S42, instructs the shading / black correction circuit 34 to perform black correction, and the shading / black correction circuit 34 determines the lighting current of the G light source. Black correction is performed by correcting the variation in dark output according to the lighting time. Then, in step S43, after the black correction data is stored in the correction data storage unit 35, the G light source 15 is turned on again. In step S44, the shading / black correction circuit 34 reads its own plate (not shown) and reads the G light source correction data. And returns to the main routine (FIG. 3).
[0055]
The above operation is first performed as an effective image area in a hand scan effective image area setting, and the driving current value / lighting time data of the LED light source 13 obtained in the effective image area setting at the time of hand scanning is read out by the CPU 6 and stored in the SRAM 2. It is stored and used as control data for hand scanning. Next, an effective image area for the current reading is set, and the original is read using the obtained driving current value / lighting time data of the LED light source 13 and the black / white reference data.
[0056]
When reading image data drawn on a sheet such as cut paper, adjustment of the lighting time of the LED light source 13 and acquisition of white reference and dark output data are performed for each reading operation. The operation is also performed at the time of initialization upon power-on. This is to enable the hand scan operation immediately after the power is turned on. If the hand scanner is not mounted on the image processing apparatus when the power is turned on, the hand scanner is mounted on the image processing apparatus. A prompt is displayed on the LCD and a voice message is played from the speaker 30. In the prescan operation when the power is turned on, shading data and black correction data in both the color copy mode and the monochrome copy mode are obtained. Since the black correction data (dark output data) is a sensor output when the LED light source 13 is not turned on, it is used as shared data regardless of the copy mode or the type of the LED light source 13 to be turned on. The correction data storage unit 35 has a capacity capable of storing one line of correction data for color R, G, B white reference data, monochrome white reference data, and shared dark output data for each sensor pixel. . At the time of hand scanning, the reading unit cannot obtain the white reference data because the reading unit is separated from the image processing apparatus. Always color on the system. When reading in monochrome White By having reference data and black reference data, during hand scanning White group There is no need to acquire quasi-data, and there are no restrictions on use.
[0057]
FIG. 5 is a flowchart showing a processing procedure at the time of hand scanning.
[0058]
That is, if there is a reading instruction in the hand scan mode, it is determined in step S51 whether or not there is valid shading data. If the answer is negative (No), the process proceeds to step S58, where the hand scanner is moved to the main image. A message is displayed on the LCD of the operation unit 18 so as to prompt the user to attach the processing unit, and a voice message is played from the speaker 30 to end the processing.
[0059]
On the other hand, if the answer to step S51 is affirmative (Yes), that is, if it is determined that there is valid shading data, the process proceeds to step S52, where various settings are made in the lighting mode setting register 41 according to the copy mode (color / monochrome). Do. In step S53, it is determined whether or not the mode is the color copy mode. If the mode is the color mode, the lighting time / lighting current and shading data of each of the R, G, and B colors in the SRAM 2 are set in step S54, and the process proceeds to step S56. move on.
[0060]
If the answer to step S53 is negative (No), that is, if the mode is the monochrome copy mode, the process proceeds to step S55, in which the lighting time and lighting current of the G light source 15 in the SRAM 2 and shading data are set, and the process proceeds to step S56. Note that the data specified at this time uses a value obtained when the above-described bliss-scan operation is performed with the hand scanner attached to the image processing apparatus.
[0061]
Subsequently, in step S56, the lighting time / current setting register 43 is set to a manual adjustment mode such that the lighting is performed according to the updated value without automatically adjusting the lighting time, and after the lighting operation is performed in step S56, the process ends. .
[0062]
Note that the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the data at the time of hand scanning is one for each of color and monochrome. However, if the data of all the patterns for the assumed effective reading width setting is acquired, the reading at the time of the hand scanning is performed. The quality can be improved.
[0063]
【The invention's effect】
As described above in detail, according to the present invention, the paper size of the original paper Effective image range based on etc. Optimal light intensity according to Adjustment Row After that, the shading correction data is acquired with the light source turned on, and then the document reading process is executed. This allows the amount of light to be Adjustment Can improve the quality of the read image when the effective image area is smaller than when performing To .
[Brief description of the drawings]
FIG. 1 is a system configuration diagram showing an embodiment of an image processing apparatus according to the present invention.
FIG. 2 is a block diagram illustrating details of an image processing unit.
FIG. 3 is a flowchart illustrating a control procedure of the image processing apparatus.
FIG. 4 is a flowchart of a prescan routine.
FIG. 5 is a flowchart of a prescan routine at the time of a hand scan.
[Explanation of symbols]
12. Reading sensor (reading means, reference light amount generating means)
13 LED light source (light source)
14 R light source
15 G light source
16 B light source
34 Shading / Black Correction Unit (Image Data Correction Unit)
35 Correction data storage unit (dark output data storage means)
40 Light quantity overflow detection circuit (light quantity reduction means)
47 light source control circuit (judgment means)

Claims (16)

At least one or more light sources for illuminating the original,
Reading means for reading the original and outputting an image signal;
Irradiating the reference member lit the light source prior to the reading of the original, light quantity detecting means for detecting an overflow of the light quantity in the effective image area from an image signal which the reading means is obtained by Rukoto reading said reference member ,
Adjusting means for adjusting a driving current and / or a lighting time of the light source so that an overflow in the effective image area does not occur when an overflow of the light amount is detected by the light amount detecting means;
Shading correction means for performing shading correction on an image signal obtained by reading the document by the reading means,
After adjusting the drive current and / or the lighting time of the light source so that the overflow in the effective image range does not occur by the adjusting unit, the reading unit can read the reference member while the light source is turned on. Control means for acquiring shading correction data for the shading correction, and thereafter controlling the reading means to execute the reading process of the document , wherein the adjusting means adjusts the drive current. An image processing apparatus characterized in that adjustment is performed prior to adjustment of lighting time. The image processing apparatus according to claim 1, wherein the reference member is white. The image processing apparatus according to claim 1, wherein the effective read range is based on the original sheet size. The adjusting means determines whether or not the drive current value is larger than a predetermined current value, and when an overflow of the light amount is detected, the drive current value gradually decreases by a predetermined minute current value until the drive current value reaches a lower limit current value. the image processing apparatus according to any one of claims 1 to 3, characterized in that lowering the. Said adjusting means, when the drive current value amount of overflow is detected reaches the lower limit current value, in claim 4, wherein the reducing gradually the lighting time by the predetermined minute lighting time The image processing apparatus according to claim 1. The light source has a light source of a plurality of colors consisting of light emitting diodes,
Before SL control means to claim 1, characterized in that independently controls the amount of each light source when reading sequentially lit in time division on a line-by-line basis by the reading means the lighting of each light source The image processing device according to claim 5 . The image processing apparatus according to claim 6 , wherein the plurality of light sources are a red light source, a green light source, and a blue light source. 8. The image processing apparatus according to claim 7 , wherein when reading monochrome image data, the image data reading operation is performed using a green light source among the light sources of the plurality of colors . Even without least irradiating the original by one or more light sources, a reading step of outputting the image signal in Rukoto reading the document by the reading means,
Irradiating the reference member lit the light source prior to the reading of the document, and light quantity detecting step of detecting an overflow of the light quantity in the effective image area from an image signal which the reading means is obtained by Rukoto reading said reference member ,
If overflow Oite amount to said light quantity detecting step is detected, an adjustment step of overflow in the effective image area to adjust the drive current and / or the lighting time of the light source so as not to generate,
A shading correction step of performing shading correction on the image signal obtained by reading the document in the reading step;
After adjusting the drive current and / or the lighting time of the light source so that the overflow in the effective image range does not occur in the adjusting step , the reading unit can read the reference member while the light source is turned on. A control step of acquiring shading correction data for the shading correction, and thereafter performing control to execute the reading process of the document in the reading step, wherein the adjusting step includes adjusting the driving current by turning on the driving current. A method for controlling an image processing apparatus, wherein the method is performed prior to time adjustment. The method according to claim 9, wherein the reference member is white. 10. The control method according to claim 9, wherein the effective reading range is based on a document sheet size. The adjusting step determines whether the drive current value is larger than a predetermined current value, and when an overflow of the light amount is detected, gradually decreases the drive current value by a predetermined minute current value until the drive current value reaches a lower limit current value. The control method for an image processing apparatus according to any one of claims 9 to 11 , wherein: 13. The method according to claim 12 , wherein the adjusting step gradually reduces the lighting time by a predetermined minute lighting time when an overflow of the light amount is detected even when the drive current value reaches the lower limit current value. The control method of the image processing apparatus described in the above. Wherein the light source comprises a plurality of colors of light sources consisting of light emitting diodes, before Symbol control step, the light amount of each light source when reading sequentially lit in time division on a line-by-line basis by the reading step the lighting of each light source method of controlling an image processing apparatus according to any one of claims 9 to 13, characterized in that independently controlled. The method according to claim 14 , wherein the plurality of light sources are a red light source, a green light source, and a blue light source. 16. The method according to claim 15 , wherein when reading monochrome image data, the image data reading operation is performed using a green light source among the light sources of the plurality of colors.

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