JP2002247296A - Image reader and image forming device using white led array as light source, recording medium and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To irradiate only an original area by using a white LED(light emitting diode) array, to read an original with high resolution and the minimum required power. SOLUTION: An image reader uses the white LED array as a light source irradiating the original and has a controller setting the lighting area of the white LED array in accordance with an original size and a purpose, a lighting area transfer part and a light source lighting control part varying ON/OFF and the light quantity of LED. The interval of each of white LED array groups where a plurality of lines of white LED array groups 1103 and 1104 are parallelly arranged in parallel is set to the prescribed number of times as much as the line interval of a light receiving element. The interval is set to that of resolution required in original reading, and the fitting position of the main scanning direction of the adjacent white LED array group is arranged by shifting it by a half pixel. Thus, a luminous LED element can be arranged with resolution higher than limited resolution which cannot be constituted on the same axis, and power can be saved by division control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image reading apparatus and an image forming apparatus using a white LED array as a light source for reading a document image, a recording medium, and a program.

[0002]

2. Description of the Related Art Hitherto, light sources such as halogen lamps, fluorescent lamps and xenon tubes have been used as light sources for high-speed image reading apparatuses. However, each of these light sources generates a large amount of heat from the light source, consumes a large amount of power, has a large lamp outer shape, requires high-voltage power supply, takes a long time to stabilize the light amount, and the like.
In addition to having various problems, the light source is of a discharge tube type or a heating wire type, so that it is not possible to control the partial light emission.

Generally, in an image reading apparatus, an operator places an original at a predetermined position on an original platen glass,
The document is fed by a document feeder (DF), the entire surface of the document is illuminated by a light source, and the document is read using a light-receiving sensor that receives light that is scattered and reflected by the document. . Further, a mirror pressure plate is used as a document pressure plate for holding down the document so that the visible light is specularly reflected and the reflected light does not reach the light receiving sensor. As described above, it can be determined that a document exists at a position where the irregularly reflected light is received by the light receiving sensor. Therefore, conventionally, the document is distinguished from the document pressure plate based on the output value of the light receiving sensor, and the document The position and size were detected.

[0004]

However, in the conventional image reading apparatus and image forming apparatus, the power consumption of the original irradiating light source is relatively high, so that the heat generated by the original irradiating light source is suppressed and unnecessary power consumption is reduced. It is desired to suppress. The above-mentioned halogen lamp, fluorescent lamp, and xenon tube cannot control lighting of only one area of the light source, and when copying a book original or a three-dimensional object such as a book, when copying with the original pressure plate open In some cases, strong original irradiation light may enter the operator's eyes, thereby damaging the eye health of the operator. In addition, with the recent increase in the speed of digital information processing technology, in order to capture a large amount of image information at a high speed, it is essential to reduce the driving load, and the voltage supplied to the light source must be lower. Realization is desirable.

[0005] In addition, dust such as a piece of paper remains on the platen glass, or the correction liquid is left on the platen glass due to the half-dryness of the correction liquid.
In some cases, the original could not be read correctly or the original could not be detected accurately.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a first object of the present invention is to use an LED array optical system to eliminate unnecessary irradiation of a region outside a document and improve the eye health of an operator. It is an object of the present invention to provide an image reading apparatus and an image forming apparatus capable of realizing power saving without harm.

A second object of the present invention is to provide an image reading apparatus which can detect dust such as a piece of paper on a platen glass and notify an operator of the position of the dust by using an LED array optical system. An object of the present invention is to provide an image forming apparatus.

[0008]

In order to achieve the first object, according to the first aspect of the present invention, a plurality of white LED arrays in which white LED light-emitting elements are arranged in an array are connected in a single row. A white LED array unit in which a plurality of white LED array groups are further arranged in parallel and in parallel, and a drive area setting means for setting a drive area of each of the white LED arrays of the white LED array unit according to a document size or use. The white LE of the white LED array unit based on the drive area set by the drive area setting means.
Partial light emission control means for generating a control signal for controlling the drive area of the D array; light source drive means for driving the white LED light emitting element of the white LED array according to a control signal from the partial light emission control means; A light-receiving element for receiving reflected light from a document illuminated by the white LED array of the white LED array unit emitted by driving of the light source driving unit and converting the reflected light into an electric signal; The spacing between the white LED arrays arranged in parallel and in parallel with each other is set to a constant multiple of the line spacing of the light receiving elements.

Here, the interval between the adjacent white LED arrays is set to the interval of the resolution required for reading a document, and the mounting position of the adjacent white LED arrays in the main scanning direction is shifted by half a pixel. Can be characterized.

The white LED array group includes an odd-numbered white LED array group including odd-numbered white LED elements and an even-numbered white LED array including even-numbered white LED elements.
An ED array group, and a light emission amount control unit that adjusts a light emission amount of the white LED array unit by individually controlling lighting of the odd-numbered white LED array group and the even-numbered white LED array group. Can be characterized.

[0011] Further, in order to adjust the light emission amount of the white LED light emitting element, it is possible to have a light emission amount control means for controlling the amount of current flowing through the white LED light emitting element.

[0012] The image forming apparatus further comprises a document size detecting means for detecting the size of the document, wherein the driving area setting means comprises a white LED in accordance with the document size detected by the document size detecting means.
A driving area of each of the white LED arrays of the array unit may be set.

[0013] In order to achieve the above object, the invention of claim 6 provides a white LED array in which white LED light emitting elements are arranged in an array in a row or an LED array group in which a plurality of the LED arrays are connected in a single row. In an image reading apparatus for reading a document image by irradiating a document on a document table with scanning light of an LED optical system having the light source moving means for moving the LED optical system, each white LE of the LED array
LED array driving means for individually emitting D light emitting elements, a light receiving element for receiving reflected light obtained by irradiating scanning light with the LED optical system on a document table on which the original is mounted, and an output of the light receiving element Detecting means for detecting the position of an object on the platen based on the light source; and moving the light source moving means based on the detection result of the detecting means.
Control means for moving the optical system to the document position and lighting the LED light emitting element at the document position by the LED array driving means.

Here, the size of the object is obtained from the detection data of the detection means, and the size is compared with a predetermined value based on the minimum document size. A determining unit that determines that there is a document when the document size is greater than or equal to the control unit; and the control unit determines whether or not the document is present, based on a detection result of the detecting unit. The LED optical system is moved to a document position, and the LED light emitting element at the document position is turned on by the LED array driving means.

An instruction means for instructing the start of pre-original detection before or after the original is read, or at a fixed period, and the light source moving means causes the LED optical system to start scanning the original in response to the instruction of the instruction means. After returning to the position,
L of the LED optical system is determined by the LED array driving means.
A second control unit that turns on an ED light-emitting element to start document detection by the detection unit, and a "left document is present" when the determination unit determines that there is a document based on the detection data of the detection unit. And a notifying means for notifying the user of the fact.

Further, when the detection data is output from the detection means, the determination means obtains the size of the object from the detection data of the detection means, and determines a predetermined size based on the size and the minimum document size. When the size of the object is smaller than the specified value, it is determined that there is dust, and when the determining unit determines that there is dust, the effect of "dust is present" is compared. Is notified.

When the determining means determines that there is dust, the control means moves the LED optical system to the center position of the dust by the light source moving means based on a detection result of the detecting means. The LED array driving means may turn on an LED light emitting element in the vicinity of the center of the dust.

Further, in the LED optical system, a plurality of white LED arrays in which a plurality of white LED arrays in which white LED light emitting elements are arranged in an array are connected in a single row are further arranged in parallel and in parallel. It can be characterized by having a white LED array unit.

Further, the white LED array unit comprises:
The interval between the adjacent white LED arrays is set to the interval of the resolution required for reading a document, and the mounting position of the adjacent white LED arrays in the main scanning direction is shifted by half a pixel. It can be.

Further, an image forming apparatus having any one of the above image reading apparatuses can be provided.

In order to achieve the above object, a fourteenth aspect of the present invention provides a white LED array in which white LED light emitting elements are arranged in an array in a row, or a plurality of such LED arrays.
In an image reading method of a device for reading a document image by irradiating a document on a document table with scanning light of an LED optical system having an LED array group connected in a row, a light source moving step of moving the LED optical system; An LED array driving step of individually emitting each white LED light emitting element of the LED array; and a light receiving element receiving reflected light obtained by irradiating a scanning light by the LED optical system on a document table on which the document is mounted, with a light receiving element. Step, a detecting step of detecting a position of an object on the document table based on an output of the light receiving element, and, based on a detection result in the detecting step, moving the LED optical system to a document position in the light source moving step. Moving the LED array, and turning on the LED light emitting element at the document position in the LED array driving step.

In order to achieve the above object, a nineteenth aspect of the present invention provides a white LED array in which white LED light emitting elements are arranged in an array in one row, or a plurality of such LED arrays.
A recording medium recording a program for controlling a device for reading a document image by irradiating a document on a document table with a scanning light of an LED optical system having an LED array group connected in a row by a computer, the program comprising: Is a computer that moves the LED optical system, causes each white LED light emitting element of the LED array to emit light, and reflects the scanning light by the LED optical system on the original table on which the original is mounted. Is received by the light receiving element, the position of the object on the document table is detected based on the output of the light receiving element, and the LED optical system is moved to the document position based on the detection result, and the LED light emission at the document position is performed. It is characterized in that the element is turned on.

In order to achieve the above object, the invention according to claim 24 is directed to a white LED array in which white LED light emitting elements are arranged in an array in one row, or a plurality of such LED arrays.
A program for controlling, by a computer, a device for reading a document image by irradiating a document on a document table with scanning light of an LED optical system having an LED array group connected in a row, and moving the LED optical system A light source moving step, an LED array driving step for individually emitting each white LED light emitting element of the LED array, and a reflected light obtained by irradiating a scanning light by the LED optical system on a document table on which the document is mounted. A light receiving step of receiving light by a light receiving element, a detecting step of detecting a position of an object on the platen based on an output of the light receiving element, and the LED moving in the light source moving step based on a detection result in the detecting step. Move the optical system to the original position, and
And a control step of turning on the LED light emitting element at the document position in the D array driving step.

(Operation) In the first embodiment of the present invention, the white L
Utilizing a light source in which the ED light emitting elements are arranged in an array, each component has a drive configuration that can be controlled independently or in a predetermined block unit, and is selected and determined from a document size setting means and a document size detecting means. A means for controlling the lighting of a white LED light emitting element corresponding to the main scanning width of the original, a photoelectric conversion means for reading reflected light from the original, and a means for scanning the original by controlling the driving of an original irradiation unit including a light source. As a result, unnecessary irradiation of the area outside the document is eliminated, and the power consumption is reduced without impairing the eye health of the operator.

In the first embodiment of the present invention, each light emission L
By arranging the center line of the ED element by a predetermined width between the light emitting LED elements of the even-numbered rows and the light emitting LED elements of the odd-numbered rows, the light emitting LED elements are arranged with a resolution higher than the limit resolution that cannot be coaxially configured. In addition, power can be saved by controlling the division of even-numbered columns and even-numbered columns.

According to a second aspect of the present invention, a document on a platen is a light source having a structure in which LED light emitting elements are arranged in an array on a chip or a plurality of LED arrays are connected in an array. Means for moving the LED optical system, means for causing each element of the LED array to emit light, and a reflected light obtained by irradiating the platen on which the original is mounted with the scanning light by the LED optical system. A light receiving element for receiving light, detecting means for detecting the presence or absence of a document on the document table based on an output of the light receiving element, and moving the LED optical system to a document position based on a result of the detecting means; And a control unit for turning on an LED corresponding to (1), it is possible to detect dust or the like that may not be able to be accurately read at the time of document detection and document reading.

[0027]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG. 1 shows a configuration of an LED array of an image reading apparatus according to a first embodiment of the present invention. Reference numeral 105 denotes an original image reading LED array;
This indicates that the pixel arrangement of the light emitting LEDs (light emitting diodes) is configured in an array. In the LED array 105, the light emitting LED elements are arranged uniformly in the document irradiation area, or only at both ends of the array structure with a high configuration density. Normally, the maximum original main scanning width is 29.
7 mm, but when the light source irradiates the document, the LED array
The light source length of 05 is set longer than the maximum document width.

Reference numeral 101 denotes a fluorescent substance (for example, a fluorescent paint) for converting the light emitted from the LED array 105 into white light. The emission characteristics (afterglow characteristics) of R (red), G (green), and B (blue) vary depending on the fluorescent substance 101, but are not particularly defined in this configuration. As described later, each light emitting LED element of the LED array 105 is arranged on a substrate (not shown) at an interval of 3 mm.

Reference numeral 120 denotes an LED array control unit, which controls lighting of each LRD chip. Here, reference numeral 106 denotes a resistor for setting a current value to be supplied to the light-emitting LED element, and a resistance value suitable for the amount of light required for the document reading system is selected. Reference numeral 108 denotes a transistor serving as a switch for controlling lighting of each light emitting LED element, and can individually control lighting of the light emitting LED elements in accordance with an LED light emission control signal output from the AND circuit 110. is there. A shift register 107 transfers an area signal (data) 102 for controlling a lighting area of the white LED array 105 in synchronization with a shift clock of the shift register 103.
As will be described in detail later, by changing the lighting area of the area signal 102 according to the size of the document, it is not necessary to turn on the LED outside the document, which can contribute to lower power consumption in the reading operation.

The output of the AND circuit 110 which receives the output of each shift register 107 and the control signal (enable signal) 104 for controlling ON / OFF of the white LED array is used as the light emitting LED of the LED array 105. The lighting control of the element is performed. That is, the lighting data shift register 1
Even when the data of each LED element for light emission is set in 07, the white LED light source 10 is in a state where the control signal 104 is not turned on (disable (logic L) state).
5 cannot be lit. Reference numeral 109 denotes a clear signal supplied to a clear terminal of the shift register 107,
While the state is held at the “H (high)” level, all the states of the shift register 107 are “L” at the “L (low)” state.
Clear to level. Note that signals 102 to 104 and 1
09 is a control signal from the controller 602 in FIG. 6 described later.

FIG. 2A shows the shift register 10 of FIG.
7 is extracted, and FIG. 2B shows the state of the data set by the shift register 107. clr-signal is a signal corresponding to the clear signal 109 in FIG. 1, and as shown in FIG. 2B, when clr-signal is "H", it is synchronized with SHIFT-CLK (shift clock). The data (area signal) indicating the lighting area is Q1, Q
2, Q3, Q4, Q5, Q6, Q7, Q8, ...
Are sequentially transferred and used as state control signals for individual LED elements.

FIG. 3 shows a commonly used original size. As is clear from the table of FIG. 3B, when using a document of a standard size, the minimum size of the difference in the main scanning width of each document is 6 mm (216 mm and 210 m).
m difference). For this reason, in order to perform lighting control according to the difference in the document size, the light emitting LED elements can be switched in units of approximately 6 mm, and the LED elements are arranged at intervals capable of irradiating uniform light to the document irradiation area. This shows that it is possible to create a light source in which the number of light emitting LED elements is optimized. Further, in the present embodiment, in order to make the lighting area of the light source closer to the document width, 3 mm, which is half of the above 6 mm, is set as the LED array interval to constitute the LED array.

Next, FIG. 4 shows a state in which the white LED array is set on an actual image reading apparatus (scanner) or image forming apparatus (copier, facsimile, or the like).
401 is an optical unit including a photoelectric conversion element such as a CCD,
Reference numeral 402 denotes a white LED array corresponding to 105 in FIG.
03 and 404 are mirror stand units, 405 is a platen glass, and 406 is an image original. An optical unit 401 including a photoelectric conversion element such as a CCD converts reflected light of document irradiation light of a white LED array 402 that irradiates an image document 406 set on a document table glass 405 with a mirror table unit 40.
Read through 3,404. As shown in FIG. 4A, the white LED array 402 lights up the original main scanning width.

As described above, the main paper sizes used in the market are as shown in FIG.
If the elements are arranged, the white LED array 402
When the total length of the LED is 330 mm, it is composed of 110 LED elements. In this configuration, when the number of lighting LED elements is further calculated for each main scanning width, the following is obtained. 139.5 mm 47 pieces 148.5 mm 50 pieces 182 mm 61 pieces 210 mm 70 pieces 216 mm 72 pieces 257 mm 86 pieces 279.4 mm 94 pieces 297 mm 99 pieces

As described above, the number of LED elements to irradiate a document differs depending on the size of the document.

FIG. 5 shows a data set when the LED is turned on.
Shown in FIG. 5A shows a white LED array 40 on an actual machine.
Reference numeral 505 denotes a lighting state, and reference numeral 505 denotes a lighting data control unit;
6 is an image original, 405 is an original platen glass, 402 is white L
It is an ED array. FIG. 5B shows a shift register 50.
5 shows a configuration example.

FIG. 5A shows a state 504 in which the white LED array 402 is lit in the entire area, and 509 and 510 in FIG. 5B show the state of the shift register at that time. I have. Here, the difference between 509 and 510 is the difference between whether the shift register has one stage or two stages. Normally, in the default state, data is set on the shift register so that all the LEDs can be turned on.

In this state, an LED element having a width corresponding to the main scanning width of the original 406 on the original platen glass 405 detected by the original size detecting unit (see a recognition unit 1704 shown in FIGS. 17 and 20 described later). Only white LED array 402
The lighting data control unit 505 sets lighting data corresponding to a corresponding lighting area of the white REL array 402 in the shift register by the lighting data control unit 505.

The structure of the shift register shown in FIG.
Reference numeral 509 denotes a single-line shift register, which is realized by shifting the entire area lighting data set in the white LED array 402 according to the document size in the default state. For this reason, if the document size determined at the second use is larger than the document size set once, after clearing the data inside the shift register once, only the required number of LEDs or all LEDs After setting the lighting data for minutes,
Original abutment position, from the mark → in FIG. 5 (required number + α)
The data shift is performed so that the minute lighting area is set.

Similarly, reference numeral 510 denotes an example in which two lines of shift registers are connected. That is, the shift register is configured in a loop, and the data for one line is 510-
As shown in FIG.
As shown by 0-b, data in the light-off state is set. Incidentally, when an LED lighting state like 501 is set, the data shift register is in a state as shown by 511. Therefore, in this case, even if the document size determined at the time of second use is large, there is no need to perform processing such as clearing data in a shift register such as a 509 single-line shift register. The data transfer state of the data shift register in this case is as shown in FIG.

Next, FIG. 6 shows a configuration example of an image reading apparatus or an image forming apparatus (hereinafter, referred to as an image forming apparatus or the like) of the present invention using the white LED array as a document illumination light source. Reference numeral 601 corresponds to an operation panel of an image forming apparatus or the like or an operation screen of a personal computer or the like. Reference numeral 602 denotes a controller that controls each function of the apparatus, and communicates with an operation panel, a personal computer, and the like.
It controls the start, stop, and operation mode settings of the device.

Reference numeral 603 denotes a pressure plate / DF open / close detecting unit for detecting whether the original pressing means (see 1602 in FIG. 16 described later) mounted on the image forming apparatus or the like is open or closed. are doing. Usually, there are two timings for detecting the document size. First, when a document reading start is requested from the operation panel 601, the controller 602 sends a detection control signal to the document size detecting unit 604, and determines the document size based on the detection data of the document size detecting unit 604. To detect. The second is that when opening / closing the pressure plate of the image forming apparatus or the like based on the detection signal of the pressure plate / DF open / close detection unit 603, the document is started from the closing state of the pressure plate until the pressure plate is closed. The controller 602 monitors a change in the detection data of the size detection unit 604 to detect the document size.

As described above, the paper size of the document is determined on the controller 602 based on the detection data of the document size detection unit 604. If the document size is known, L to light up
The number of ED elements is determined, and the data shift operation is performed by the light source lighting area data transfer unit 605 so that data is set in the lighting area.

As described above, in the present configuration, the total number of the LED elements constituting the white LED array is 110. Therefore, even if all the data is transferred again, if the transfer rate is 10 MHz, it is 11 μsec. (= 0.1μ
The data transfer is completed in a transfer time of (sec × 110). When this is applied to a commonly used original size document, for example, in the case of A4 size, this A4 size
Data transfer for 11 (= 110−99) is required so that the required number of LEDs is 99 in size. The time required for this is completed in 1.1 μsec from the above description.

Reference numeral 606 denotes a light source lighting control unit for controlling lighting of the light source (white LED array), that is, ON / OFF of the light source. In the present embodiment, the lamp (LED) is turned on by outputting an “H” level to the control signal 104 in FIG. 1 through the light source lighting control unit 606. The “H” level and “L” level signals are sent to the controller 6
It is assumed that the control is performed using a CPU port on the CPU 02 (see 1706 in FIG. 17 described later).

Reference numeral 607 denotes a motor control unit for driving and controlling the mirror base unit including the white LED array in the sub-scanning direction. Reference numeral 608 denotes an image processing unit which processes and corrects video data of a document image photoelectrically converted by the optical unit 401 in FIG. 4 (such as pixel level variation correction such as shading correction) and stores the video data in a storage device (not shown). I do.

One of the functions of the light source lighting control unit 606 for adjusting the light amount of the white LED array is as follows.
A lighting control method using high-frequency lighting is preferable, and a configuration example of the high-frequency lighting control will be described with reference to FIGS.
The high-frequency lighting control of the light source (white LED array) is performed by a reading element (CC constituting the optical unit 401 in FIG. 4).
If the synchronization is not performed with D), the output image will flicker. Therefore, in the present invention, a method of keeping the LED lit at the time of image reading and a method of holding the horizontal synchronization signal (HSYN)
The method is realized by two methods of synchronizing high-frequency lighting with C).

In FIG. 7, HSYNC 701 is a horizontal synchronization signal for reading a document. LAMP1 of 702
Indicates a state in which the LED is always turned on when reading the document, and LAMP2 703 indicates an example in which the lighting time is varied within the cycle of the horizontal synchronization signal. Typically,
The CCD used for reading the original image obtains a reading level for each pixel by an integrated value of the amount of light received within the accumulation time. On the other hand, a light source (L) used for reading the CCD is used.
ED), the light amount can be adjusted by adjusting the lighting time.

Similarly, LAMP3 704 shows an example in which the lighting time is adjusted with reference to the center of the horizontal synchronization time, unlike the lighting time adjustment in LAMP2 703, and has a center adjusted waveform. is there. The advantage of using the center adjustment waveform is that by using the center adjustment waveform,
The difference is that differences unique to the emission color, such as the afterglow characteristics of the fluorescent paint used in the white LED array, can be absorbed.

Reference numeral 705 indicates the relationship between the lighting time of the LED and the illuminance, although not strict, applied to a simple graph. That is, within the period of the horizontal synchronization signal, the LED
It is considered that the longer the lighting time of, the higher the illuminance on the document.

FIG. 8 shows a configuration example of a circuit for performing high-frequency lighting described with reference to FIG. This circuit is PWM (pulse width modulation)
However, in the present embodiment, an example using a counter and a comparator is used. In FIG. 8, reference numeral 801 denotes a counter configured by the number of stages that operate within the cycle of HSYNC (horizontal synchronization signal) 805. The counter 801 is reset by HSYNC 805,
It is counted up by the input clock (CLK) 806. Reference numerals 802 and 803 denote comparators for comparing the count value of the counter 801. The comparators 802 and 803 output timings for turning on and off the LEDs when performing high-frequency lighting in accordance with a setting (comparison data set) 808 from the controller. . Based on the edge signals output from the comparators 802 and 803, the lighting control signal 807, that is, 70 in FIG.
3,704 lighting control signals are generated to enable LED lighting control.

Next, referring to the flowchart of FIG.
A series of operations described above in one embodiment of the present invention will be described.

The start of the operation in step 901 means the start of the operation of the operator when reading the original. In the next step 902, it is detected whether or not the document feeder is mounted.
Normally, communication is performed between the document reading device and the document feeding device, so whether or not the document feeding device is mounted is determined regardless of the operation of the operator. If it is determined in step 902 that the document feeder is mounted, step 9
At 03, it is determined whether or not a document is set. There are two types of document setting methods. One is to load documents on the document tray of the document feeder, and the other is to set the document directly on the platen glass by opening and closing the document feeder in the same way as the pressure plate. Divided into If it is determined in step 903 that a document is set, the width of the document is detected in step 904.

The method of detecting the document width in step 904 is as follows. A document feeder (not shown) is provided with a document guide (a variable document width guide for aligning documents), and the document width is usually detected at a set position of the document guide. In addition, a flag-cut sensor or an optical sensor is installed in the feed path that feeds the document from the document stacking unit onto the platen glass, and these sensors detect the length from the leading edge to the trailing edge of the document. , The length of the original in the longitudinal direction (sub-scanning direction) is detected.

When the document width is determined in step 904, the data transfer method shown in FIG.
In step 9, a light source lighting area data set is performed, and in step 910, lighting control of the white LED array is performed.

However, if it is determined in step 903 that the original is not set even if the original feeder is mounted, the opening / closing operation of the original feeder is detected in step 906. At this time, the operator opens the document feeder upward without setting the document on the document feeder,
When the original is set directly on the original platen glass, when the operator closes the original feeder again, step 90 is performed.
In step 8, document size detection is started, and the document size is detected using a document size detection sensor (not shown). That is, in the circuit configuration of FIG. 6, the controller 602 sends a control signal to the document size detection unit 604 in response to the detection of the start state of closing the document feeder by the pressure plate / DF open / close detection unit 603 and starts document size detection. Then, a change in the output signal of the document size detection unit 604 is monitored to detect the document size. When the document width is determined in step 908, the light source lighting area data set is performed in step 909 by using the data transfer method as shown in FIG. 5, and the lighting control of the white LED array is performed in step 910.

If the opening / closing of the document feeder is not detected in step 906, the process waits for a copy button (copy start button) in step 907. If the copy button is not pressed, the flow returns to the pressure plate open / close detection flow in step 905, and the loop of steps 907 and 905 is repeated until the pressure plate is opened / closed or the copy button is pressed, and a predetermined time set by the controller is set. Enter standby state. If the press platen is opened or closed or the copy button is pressed, the document size is detected in step 908. When the document width is determined in step 908, the light source lighting area data set is performed in step 909 by using the data transfer method as shown in FIG. 5, and the lighting control of the white LED array is performed in step 910.

On the other hand, if the document feeder is not mounted, the operation starts from the pressure plate open / close detection flow in step 905, and steps 907 and 905 are performed until the press plate opening / closing operation or the copy button is pressed. Is repeated, and the apparatus enters a standby state for a predetermined time set by the controller. If the press platen opening / closing operation or the copy button is pressed, document size detection in step 908 is performed.
When the document width is determined in step 908, the light source lighting area data set is performed in step 909 by using the data transfer method as shown in FIG. 5, and the lighting control of the white LED array is performed in step 910.

An example of the basic configuration and control method of a document irradiation light source using a white LED array has been described.
Similarly, an example of another basic configuration of the present invention will be briefly described.

FIG. 2 shows a configuration in which the lighting control section of the white LED array is changed in the configuration of FIG. In this circuit, lighting of the light emitting LEDs is controlled collectively by 1010 switch transistors as lighting switches of all the light emitting LEDs.
The steps 101 to 109 are the same as the steps 101 to 109 in FIG. An advantage of the configuration shown in FIG. 2 is that the number of component parts is small, but the same operation is functionally possible.

FIGS. 11 and 12 show a white LED in which light emitting LED elements are arranged in a zigzag pattern, which is representative of the first embodiment of the present invention.
3 shows an ED array. This white LED array has a light emitting LE
When high-density mounting of the D element, the data shift register,
And a lighting control circuit for each light-emitting LED element is divided into an even-numbered row and an odd-numbered row, and the center line of each light-emitting LED element is divided into an even-numbered row of light-emitting LED elements 1104 and an odd-numbered row of light-emitting LED elements 1103. In this configuration, the light emitting LED elements are arranged at a resolution higher than the limit resolution that cannot be coaxially arranged by displacing them by a predetermined width. Therefore, as shown by the lines 1101 and 1102, each control circuit is configured in a line shape on separate side surfaces in even and odd columns.

FIG. 11 shows a structure particularly designed for high-density mounting. With the configuration as shown in FIG. 11, it is possible to configure a light emitting LED array with twice the resolution. On the other hand, FIG. 12 shows a configuration in which power saving is realized by controlling division of even and odd columns rather than increasing the density.

Further, reference numeral 1105 in FIG. 11 denotes a white LED array block. FIG. 11 shows an example in which a longer white LED array can be formed by arranging a plurality of white LED array blocks 1105.
FIGS. 13 and 14 show circuit configuration examples of the LED array control unit of the white LED array block 1105. FIG. Figure 1
The basic configuration of FIGS. 3 and 14 is the same as that of FIG. 1, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

Reference numerals 1301 and 1302 in FIG.
Are shown. The circuit of FIG. 13 does not clearly divide the even-numbered column and the odd-numbered column, but employs a configuration in which the even-numbered column and the odd-numbered column can be separately controlled for lighting via the lighting control lines 1301 and 1302. For example, when the light amount is small, the lighting control line 1302 may be set to the H level to control the lighting of only the even-numbered light emitting LEDs.

In the circuit of FIG. 14, the data line 102 for odd columns and the data line 1401 for even columns are individually formed for the data shift register 107, and the shift clock 103 and the clear signal 109 are shared. Has taken. In addition, the lighting control line is also 140 for odd lines.
2, 1403 for even lines.

The lighting control lines 1402 and 1403 are handled. If high-density mounting is performed in a staggered arrangement as shown in FIG.
By performing the toggle control on the lighting control line 403, the power consumption can be reduced by half and used.
It is also possible to reduce the number of control lines by sharing the lighting control lines of 02 and 1403. Note that 10 in FIG.
1 to 110 have the same configuration as 101 to 110 in FIG.

(Modification of the First Embodiment) In the description so far, the method of adjusting by the high frequency lighting as the light amount adjusting mechanism has been described. FIG. 15 shows the method of controlling the light amount of the LED array without using the high frequency lighting. 4 shows a circuit configuration according to an adjustment method for adjusting. 15 differs from the circuit of FIG. 1 in that a D / A converter 1501 and a transistor 1502 as a potential discharge switch are connected to a ground line. In this configuration, the transistor 1
The state in which 502 is turned on is a state in which the light-emitting LED is turned on MAX (lighting at the maximum light amount). On the other hand,
By adjusting the D / A converter 1501 with the transistor 1502 turned off to increase the potential, the amount of current flowing through the light emitting LED decreases.
The light amount of the D array can be adjusted.

[(Set value of Vcc-D / A)] ÷ Resistance 10
Resistance value of 6] It is also possible to adjust the light quantity at the time of scanning the original by such a method.

Although not particularly described in the description so far, in the lighting control of the white LED array, it is also possible to control the lighting of all the LEDs from the operation panel 601 to read the original. This is to cope with an object such as an irregular-sized original or a three-dimensional original, which cannot be accurately detected in some originals.

Although the timing of turning off the light when scanning the original is not specifically described in the above description, the sub-scanning size can be detected when the above-described original size is detected, and the mirror base unit including the light source (white LED array) can be detected. From the scanning speed and the timing of the horizontal synchronization signal (HSYNC), the count number of the HSYNC corresponding to the detected sub-scanning size is obtained, and after reaching the count number, the white LED array is turned off in the controller. Turns off the light source.

(Second Embodiment) FIG. 16 shows a second embodiment of the present invention.
Image reading device (or image forming device) in the embodiment
1 shows an arrangement configuration. Reference numeral 1601 denotes the entire image reading apparatus, and reference numeral 1602 denotes a document pressing plate. A document 1604 on a platen glass 1603 covered with a document pressure plate 1602 is irradiated with light from the white LED array 105. Manuscript 160
The reflected light from 4 is guided to mirrors 1606 and 1607,
A line sensor (hereinafter referred to as CCD) 16 is provided by a lens 1608.
Form an image on 10. The lens 1608 is provided with a far-infrared cut filter 1631.

The CCD 1610 reads optical information from the original 1604 and converts the read data into a signal processing unit 1609.
Send to

The speed of the white LED array 105 and the mirror 1606 is v, and the speed of the mirror 1607 is ｖ v, the direction perpendicular to the electrical scanning direction (hereinafter, the main scanning direction) of the line sensor 1610 (hereinafter, the sub-scanning direction). The entire original is scanned by mechanically moving the original. Reference numeral 1630 denotes an optical sensor, together with a flag plate 1629, an image tip signal VTOP.
To produce

The circuit configuration of the white LED array and its control unit is the same as that of the first embodiment shown in FIG.
0, any of FIG. 13, FIG. 14, and FIG. 15), and a detailed description thereof will be omitted.

Further, similarly to the first embodiment of the present invention,
The white LED array 105 has a pixel array of light-emitting LEDs arranged in an array, and the light-emitting LEDs are arranged evenly in the document irradiation area or with a high configuration density only at both ends of the array structure. Also, when the white LED array 105 of the light source irradiates the document, the light source length of the white LED array 105 is set to be longer than the maximum value of the main scanning width of the document so that the edge light amount does not decrease. Is set to Further, by changing the lighting area of the area signal according to the document size, it is not necessary to turn on the LEDs in the area outside the document, and it is possible to contribute to lower power consumption in the reading operation.

FIG. 17 shows the image reading apparatus 1601 shown in FIG.
2 shows a circuit configuration example of the signal processing unit 1609 of FIG. In FIG. 17, reference numeral 1701 denotes a clock generation unit which generates a clock for each pixel. The main scanning address counter 1702 is an up counter, counts clocks, and generates a one-line pixel address output. A decoder 1703 decodes a main scanning address from the main scanning address counter 1702, and outputs a CCD drive signal such as a shift pulse and a reset pulse in units of lines, and a CCD 1610.
, A VE signal representing an effective area in a one-line read signal and a line synchronization signal HSYNC. The main scanning address counter 1702 is cleared by the HSYNC signal, and starts counting the main scanning address of the next line.

Reference numeral 1704 denotes a recognizing unit which performs document detection and dust detection which will be described later, which is a feature of the present invention. CCD 1610
The output signal is adjusted by the image signal processing unit 1705 for gain adjustment,
Processing such as offset adjustment, A / D conversion, and shading correction is performed and sent to the recognition unit 1704. 1706
Is a CPU (Central Processing Unit), which is a motor 17
07 via the LED array control unit 120
Performs sequence control such as lighting control of the D array 105,
A sub-scanning direction pixel section signal VSYNC is generated. The CPU 1706 supplies the signals 102 to 104 and the signal 109 in FIG.

Reference numeral 1710 denotes a sub-scanning address counter, which counts the line synchronization signal HSYNC using the pixel section signal VSYNC in the sub-scanning direction as a clear signal, and supplies the count value to the recognizing unit 1704 as a sub-scanning address. The main scanning address from the main scanning address counter 1702 is also supplied to the recognition unit 1704.

FIG. 18 shows the timing of each control signal shown in FIG. The VSYNC signal is an image valid section signal in the sub-scanning direction, and forms an output signal of document detection and image reading (scanning) in a section of “1”. V
E is an image valid section signal in the main scanning direction, and the timing of the main scanning start position is set in the section of “1”. HSY
The NC signal is a line synchronization signal as a horizontal synchronization signal for reading a document. The CLOCK signal is a pixel synchronization signal, and transfers image data at the rising timing of “0” → “1”.

Next, a method of detecting a document on the platen glass will be described with reference to FIG. FIG. 19 shows a state where an original 1604 is placed on an original platen glass 1603 of the image reading apparatus. Basic coordinates SP on original glass 1603
From the (upper left corner in the figure), the main scanning direction is X, and the sub-scanning direction is Y. At this time, the coordinates of the document closest to the basic coordinates SP in the sub-scanning direction are (X1, Y1), the coordinates of the document closest to the basic coordinates SP in the main scanning direction are (X2, Y2), and the coordinates of the document closest to the basic scanning direction are The coordinates of the document far from SP are (X3,
Y3), the coordinates of the document farthest from the basic coordinates SP in the sub-scanning direction are (X4, Y4).

The coordinates of these four points are assigned to the white LED array 105.
Is prescanned and detected. That is, based on the original reading signal obtained via the CCD 1610 and the image signal processing unit 1705, the recognition unit 1704 detects the coordinates of the four points. CP
U1706 can determine the size of the document and the position on the platen glass based on the coordinates of the four points.

FIG. 20 shows an example of the configuration of a logic circuit of the recognition unit 1704 for detecting the coordinates of the above four points. In the pre-scanning of the white LED array 105, a document reading signal from the image signal processing unit 1705 is compared with the comparator 2007 of the recognizing unit 1704.
Supplied to The original reading signal is supplied to the comparator 20
At 07, the size is compared with the predetermined slice level to obtain 2
Valued. The binarized original reading signal is aligned in shift register 2001 with the presence / absence information of the original for eight consecutive pixels, and whether or not all the consecutive eight pixels indicate "the existence of original" is detected by AND gate 2002. I do.

The AND gate 2002 checks whether or not all of the eight pixels are original reading signals indicating "there is an original." If the result is Yes (affirmative determination), the signal 2003 on the signal line is set to "1". If No (negative determination), “0” is output as the signal 2003 of the signal line.
003 is input to an F / F (flip-flop circuit) 2004.

The F / F 2004 is reset before the start of the original scanning, and when the original reading signal appears for all eight pixels after the start of the original scanning, the output of the AND gate 2002 becomes "1" and the F / F 2004 is set. Is done. F / F
At the timing when the output of 2004 changes from “0” to “1”, the main scanning address counter 1 at that time is stored in the latch 2005.
702 (or dedicated counter) value (main scanning address)
Is loaded. That is, the original platen 1 detected for the first time
The coordinates of the original 1604 on 603 are recorded in the latch 2005. This becomes the X1 coordinate value. In addition, the latch 200
6, the value (sub-scanning address) of the sub-scanning address counter 1710 (or dedicated counter) at that time is loaded. This becomes the Y1 coordinate value. Therefore, P1 (X
1, Y1) is determined.

The signal 20 from the AND gate 2002
03, the value (main scanning address) from the main scanning address counter 1702 and the latch 201
5 (which is set to “0” by VSYNC) is compared in magnitude by the comparator 2016. If the data of the main scanning address counter 1702 is larger, the AND gate circuit 2017 sets the latch 2015, so that the data (main scanning address) of the main scanning address counter 1702 is loaded into the latch 2015.
At this time, the value of the sub-scanning address counter 1710 is loaded into the latch 2018. This operation is processed until the next eight pixels enter the shift register 2001. Thus, the main scanning address counter 1702 and the latch 201
5 is performed for all image areas, latch 2
015, the maximum value in the document area X direction remains, and the coordinates in the Y direction at this time remain in the latch 2018. This is P3 (X3, Y3).

Similarly, signal 2 from AND gate 2002
Each time “1” is output to the counter 003, the value from the main scanning address counter 1702 and the latch 2010 (which is VSYN
The maximum value in the main scanning direction is set at C) by the comparator 2009. If the value of the latch 2010 is larger than the value of the main scanning address counter 170
If the value is greater than or equal to 2, the gate circuit 2008 sets the latch 2010, so that the value of the main scan address counter 1702 is loaded into the latch 2010. This operation is performed between HSYNC and HSYNC. When the comparison operation described above is performed for all image areas, the minimum value of the document coordinates in the X direction remains in the latch 2010. This is X2. At this time, the value from the sub-scanning address counter 1710 is loaded into the latch 2010. This becomes Y2. Therefore, P2 (X2,
Y2) It is determined.

The latches 2019 and 2020 are loaded with the value of the main scanning address counter 1702 and the value of the sub-scanning address counter 1710 each time an 8-bit document appears in the entire image area. Therefore, when the original pre-scanning is completed, the counter values at the time when the eight-pixel original finally appears remain in the latches 2019 and 2020. This is P4 (X4, Y4).

The above eight latches (2006, 202
0, 2011, 2018, 2005, 2010, 201
5, 2019) is connected to the bus line (BUS) of the CPU 1706, and the CPU 1706 detects the position and size of the original by reading the data (coordinate data) of these eight latches at the end of the original detection scanning.

Then, the CPU 1706 determines the area of X2, X3, Y1, Y4 among these data as the original area. The CPU 1706 calculates X2 of the coordinate component of the document.
The document position P indicated by a broken line in FIG.
By recognizing the coordinates of a rectangle surrounding 1 to P4, the position and size of the document can be automatically detected.

Further, by performing this document detection operation (pre-document detection) before loading the document on the document table glass 1603, it is possible to detect dust such as a piece of paper on the document table glass 1603 or misplacement of the document. . Normally, before reading the original, the operator operates the operation unit (60 in FIG. 6).
When a pre-document detection operation is instructed from 1), the above-described document detection is performed. However, if the pre-document detection is performed every time before reading the document, the reading operation time becomes long. Therefore, the automatic reading operation may be performed after the reading operation is completed or at a time set by the operator.

FIG. 21 is a flowchart showing the processing procedure of the CPU 1706 relating to the pre-document detection operation. First, in step 2101, when the pre-document detection operation is started according to the instruction of the operator or the set time, the process proceeds to step 21.
In step 02, the optical systems 1606 and 1607 are returned to the scanning start positions. In step 2103, the document detection operation starts. If there is dust on the platen glass 1603, such as a misplaced document or a piece of paper, the coordinate components X1 to X4 and Y1 to
Since Y4 is recognized, a document or dust is present. When these are recognized in step 2104, in step 2105 the RAM in the CPU 1706 is
This coordinate component is stored in a memory (not shown). Next, the process proceeds to step 2106.

On the other hand, if there is no original or dust in step 2104, the present process is terminated, and a state of waiting for original reading starts. Thereafter, a document is supplied from a document feeder (not shown) onto the platen glass 1603, and a document reading operation is performed.

In step 2106, the area S of the load is calculated from the coordinate components stored in the RAM (not shown). If the area S of the load is equal to or larger than the predetermined area S1 in step 2107, the original is read. It is determined that there is a document 1604 left behind on the base glass 1603, and if the area S of the load is equal to or smaller than a predetermined area S1, it is determined that there is dust.

If it is determined that the document is a misplaced document, a message such as "There is a document misplaced on the platen glass" is displayed on the display screen (not shown) of the operation unit (step 2111). ).

If it is determined that there is dust, a message such as "There is dust on the platen glass" is displayed on an operation unit (not shown) in step 2108. As a result, the operator can perform accurate document detection and document reading without reading dust.

Further, in step 2109, the LED array optical system is moved to the Y coordinate (Y4−Y1) / 2 which is the center of the dust position, and in step 2110, the X coordinate (X3-X2) / the center of the dust position By turning on only the LED closest to No. 2, the operator can recognize where the dust is actually on the platen glass.

Of course, if it is difficult for the operator to see only the nearest LED, it is only necessary to light several LEDs in the vicinity at the same time.

(Modification of Second Embodiment) The second embodiment of the present invention
This embodiment may be combined with the first embodiment. In this case, a synergistic effect can be expected.

(Other Embodiments) Even if the present invention is applied to a system constituted by a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus comprising one device (For example, a copying machine, a facsimile machine, a scanner, etc.).

An object of the present invention is to provide a system or an apparatus with a recording medium (storage medium) in which software program codes for realizing the functions of the above-described embodiments are recorded, and the computer of the system or the apparatus is provided. Needless to say, the present invention is also achieved when the CPU (or the CPU or the MPU) reads out and executes the program code stored in the recording medium.

In this case, the program code itself read from the recording medium realizes the function of the above-described embodiment, and the recording medium on which the program code is recorded constitutes the present invention.

As a recording medium for recording the program code and variable data such as a table, for example, a floppy disk (FD), hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, A nonvolatile memory card (IC memory card), a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. It goes without saying that an operating system) may perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

[0105]

As described above, according to the present invention, by using a white LED array as a document irradiating light source, it is possible to irradiate only an area corresponding to the size of a document, thereby suppressing unnecessary power consumption. It becomes possible. In addition, since the light of the light source can be prevented from leaking to the area other than the original as in the conventional case, even when copying with the pressure plate or the original feeding device released, the original illumination light that is unpleasant to the eyes of the operator can be obtained. It can also be prevented from entering.
Further, since the light emitting LED can control light emission at a low voltage, it is possible to reduce the size of a power supply mounted on the device and to simplify the handling.

Further, according to the present invention, the center lines of the light emitting LED elements are shifted by a predetermined width between the light emitting LED elements in the even-numbered rows and the light emitting LED elements in the odd-numbered rows, thereby forming a coaxial structure. The light emitting LED elements can be arranged with a higher resolution than the limit resolution that cannot be achieved, and power saving can be achieved by controlling the division of the even-numbered columns and the even-numbered columns.

Further, according to the present invention, by detecting the presence or absence of a document on the platen glass before reading the document, dust on the platen glass can be easily detected, and the operator removes the dust. Thus, after a document is mounted on the platen glass, accurate document detection and document reading can be performed.

[Brief description of the drawings]

FIG. 1 is a circuit diagram illustrating a typical basic configuration example of a white LED array and an LED array control unit according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram (A) extracted from a data shift register portion of the LED array of FIG. 1 and a timing chart (B) illustrating an operation of the data shift register.

FIGS. 3A and 3B are a plan view (A) and a list (B) showing various original sizes of a standard size.

FIG. 4 is a plan view (A) and a longitudinal sectional view (B) showing a configuration example of an image reading apparatus or an image forming apparatus to which the white LED array according to the first embodiment of the present invention is applied.

5A and 5B are a schematic diagram illustrating an example of lighting control of a white LED array corresponding to a document size and a schematic diagram illustrating a configuration example of a shift register according to the first embodiment of the present invention.

FIG. 6 is a block diagram illustrating a schematic circuit configuration example of an image reading apparatus or an image forming apparatus according to the first embodiment of the present invention.

FIG. 7 is a timing chart illustrating an operation example of lighting control of a white LED array according to the first embodiment of the present invention.

FIG. 8 is a block diagram illustrating an example of a circuit configuration for easily realizing high-frequency lighting control for a white LED array according to the first embodiment of the present invention.

FIG. 9 is a flowchart illustrating a control operation according to the first embodiment of the present invention.

FIG. 10 shows a white LED according to the first embodiment of the present invention.
FIG. 9 is a circuit diagram illustrating a second basic configuration example of an array and an LED array control unit.

FIG. 11 is a schematic plan view showing an arrangement configuration example of a white LED array having a staggered configuration according to the first embodiment of the present invention.

FIG. 12 is a schematic plan view showing another example of the arrangement configuration of the white LED array having the staggered configuration according to the first embodiment of the present invention.

FIG. 13 shows a white LED array and an LED in the first embodiment of the present invention, which can control lighting of even-numbered rows and odd-numbered rows separately.
FIG. 3 is a circuit diagram illustrating a configuration of an array control unit.

FIG. 14 shows a white LED array in which control circuits for even-numbered columns and odd-numbered columns in the first embodiment of the present invention are completely separated from each other;
FIG. 3 is a circuit diagram illustrating a configuration of an ED array control unit.

FIG. 15 is a circuit diagram illustrating a configuration of a white LED array and an LED array control unit when adjusting the light amount of the LED according to the first embodiment of the present invention.

FIG. 16 is a plan view (A) and a longitudinal sectional view (B) showing a configuration example of an image reading apparatus or an image forming apparatus according to a second embodiment of the present invention.

17 is a block diagram illustrating a configuration example of a signal processing unit of the image reading device or the image forming device in FIG.

18 is a timing chart illustrating control signals of the signal processing unit in FIG. 17;

FIG. 19 is a conceptual diagram illustrating a relationship between a state where a document is placed on a platen glass and coordinates of a document to be detected in the second embodiment of the present invention.

20 is a block diagram illustrating a circuit configuration of a logic circuit of a recognition unit that performs document detection in FIG. 17;

FIG. 21 is a flowchart illustrating an operation of a control process according to the second embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 101 fluorescent substance (fluorescent paint) 102 control signal (data) 103 shift clock 104 control signal (enable signal) 105, 402 white LED array 106 resistor 107 shift register 108 transistor 109 clear signal 110 AND circuit 401 optical unit 403, 404 mirror base Units 405, 1603 Platen glass 406, 1604 Document 601 Operation panel 602 Controller 603 Pressure plate / DF open / close detection unit 604 Document size detection unit 605 Light source lighting data transfer unit 606 Light source lighting control unit 607 Motor control unit 801 Counter 802, 803 Comparator 804 JK flip-flop 1010 Transistor 1103 Odd-numbered white LED array 1104 Even-numbered white LED array 1105 White LED array Blocks 1301, 1302 Lighting control line 1401 Data line for even number line 1402 Lighting control line for odd line 1403 Lighting control line for even line 1501 D / A converter 1502 Transistor 1601 Image reading device (or image forming device) 1602 Original platen 1606 1607 Mirror 1608 Lens 1609 Signal processing unit 1610 Line sensor (CCD) 1629 Flag plate 1630 Optical sensor 1631 Filter 1701 Clock generation unit 1702 Main scanning address counter 1703 Decoder 1704 Recognition unit 1705 Image signal processing unit 1706 CPU 1707 Motor 1708 Motor driver 1710 Sub Scan address counter 2001 shift register 2002, 2008, 2027 AND gate 2003 signal 2004, 2012, 2013 F / F (flip-flop circuit) 2005, 2006, 2010, 2011 Latch 2015, 2018, 2019, 2020 Latch 2007, 2009, 2016 Comparator

Continued on the front page F-term (reference) 2H027 DA01 DA07 DA25 DA32 DB03 DB06 DB09 DB10 DE02 DE07 DE09 DE10 EA02 ED06 ED07 EE01 EE07 EE08 EE10 EF06 EF08 EK01 GA32 GA45 GA48 GB01 GB07 HA02 HA04 HA06 HA12 HA20 ZA07 AH47A A2AB9 AA01 BA02 BB02 BC12 CB05 5C051 AA01 BA02 DA03 DB01 DB04 DB07 DB29 DC02 DC05 DC07 5C072 AA01 CA05 CA18 EA05 LA02 MB01

Claims (28)

[Claims] 1. A white LED in which a plurality of white LED arrays in which white LED light emitting elements are arranged in an array in a row are connected in a single row.
A white LED array unit in which a plurality of ED array groups are further arranged in parallel and in parallel with each other; a drive region setting means for setting a drive region of each of the white LED arrays of the white LED array unit according to a document size or a use; A partial light emission control unit that generates a control signal for controlling a drive region of the white LED array of the white LED array unit based on the drive region set by the drive region setting unit; and a control signal from the partial light emission control unit. Light source driving means for driving the white LED light-emitting element of the white LED array according to the following; and the white LED which emits light by driving the light source driving means
A light receiving element for receiving reflected light from a document irradiated by the white LED array of the array unit and converting the reflected light into an electric signal, wherein the white LED array group is arranged in a plurality of rows in parallel and in parallel. An image reading apparatus wherein an interval between the white LED array groups is set to a constant multiple of a line interval between the light receiving elements. 2. An interval between the adjacent white LED arrays is set to an interval of a resolution required for reading a document, and a mounting position of the adjacent white LED arrays in the main scanning direction is shifted by half a pixel. The image reading device according to claim 1, wherein the image reading device is arranged. 3. The white LED array group includes an odd-numbered white LED array group including odd-numbered white LED elements and an even-number white LED group including even-numbered white LED elements.
A light emitting amount control unit for controlling the light emitting amount of the white LED array unit by individually controlling the lighting of the odd-numbered white LED array group and the even-numbered white LED array group. The image reading device according to claim 2, wherein: 4. The image according to claim 1, further comprising: a light emission amount control unit that controls an amount of current flowing through the white LED light emitting element in order to adjust a light emission amount of the white LED light emitting element. Reader. 5. A document size detecting means for detecting a size of a document, wherein the driving area setting means determines a size of each of the white LED arrays of the white LED array unit according to a document size detected by the document size detecting means. 5. The image reading apparatus according to claim 1, wherein a driving area is set. 6. A white LED array in which white LED light emitting elements are arranged in an array in one row, or a scanning light of an LED optical system having an LED array group in which a plurality of the LED arrays are connected in a single row on a document table. In an image reading device that reads a document image by irradiating a document, a light source moving unit that moves the LED optical system, an LED array driving unit that individually emits each white LED light emitting element of the LED array, A light receiving element for receiving reflected light obtained by irradiating the LED optical system with scanning light on the mounted platen, and a detecting means for detecting a position of an object on the platen based on an output of the light receiving element Moving the LED optical system to a document position by the light source moving means based on the detection result of the detecting means;
An image reading device comprising: a control unit for lighting an LED light emitting element at a document position by a D array driving unit. 7. The size of the object is determined from the detection data of the detection means, and the size is compared with a predetermined value based on the minimum document size, and the size of the object is larger than the predetermined value. If the values are equal, the control unit includes a determination unit that determines that there is a document. When the determination unit determines that the document is present, the control unit determines the presence of the document based on the detection result of the detection unit. 7. The image reading apparatus according to claim 6, wherein the LED optical system is moved to the document position, and the LED light emitting element at the document position is turned on by the LED array driving means. 8. An instruction means for instructing the start of pre-original detection before or after an original is read, or at a predetermined period, and the LED optical system is started to scan the original by the light source moving means in accordance with the instruction of the instruction means. After returning to the position, the LE
A second control unit for turning on the LED light emitting element of the LED optical system by the D array driving unit to start detecting the original by the detecting unit; 8. The image reading apparatus according to claim 7, further comprising: a notifying unit for notifying that "the document is left behind" when it is determined that the document is left behind. 9. When the detection data is output from the detection means, the determination means obtains the size of the object from the detection data of the detection means, and determines a predetermined size based on the size and the minimum document size. The size of the object is smaller than the specified value, and it is determined that there is dust. If the determination unit determines that there is dust, the notification means that there is dust. The image reading device according to claim 7, wherein the notification is performed. 10. When the determination unit determines that there is dust, the control unit moves the LED optical system to a center position of the dust by the light source moving unit based on a detection result of the detection unit. The image reading apparatus according to claim 9, wherein the LED array driving unit turns on an LED light emitting element in the vicinity of a center position of the dust. 11. The LED optical system further includes a plurality of white LED arrays in which a plurality of white LED arrays in each of which a plurality of white LED arrays are arranged in a row are arranged in parallel and in parallel. The image reading device according to claim 6, further comprising a white LED array unit. 12. The white LED array unit sets an interval between adjacent white LED arrays to an interval of a resolution required for reading a document, and attaches the adjacent white LED arrays in a main scanning direction. The image reading apparatus according to claim 11, wherein the positions are shifted by a half pixel. 13. An image forming apparatus comprising the image reading device according to claim 1 as image reading means for reading a document image. 14. An LED having a white LED array in which white LED light emitting elements are arranged in an array in one row, or an LED array group in which a plurality of the LED arrays are connected in one row.
In an image reading method of a device for reading a document image by irradiating a document on a document table with a scanning light of an optical system, a light source moving step of moving the LED optical system, and individually controlling each white LED light emitting element of the LED array An LED array driving step of causing the LED optical system to irradiate scanning light on a document table on which the document is mounted, and receiving a reflected light obtained by a light receiving element, based on an output of the light receiving element. Detecting the position of an object on the platen by moving the LED optical system to the document position in the light source moving step based on the detection result in the detection step, and moving the document in the LED array driving step. A control step of turning on the LED light emitting element at the position. 15. The size of an object is obtained from the detection data in the detection step, and the size is compared with a predetermined value based on a minimum document size. A determining step of determining that there is a document when the document is larger or equal to each other; and in the controlling step, when determining that the document is present in the determining step, the light source moving based on a detection result in the detecting step. 15. The image reading method according to claim 14, wherein the LED optical system is moved to a document position in a step, and the LED light emitting element at the document position is turned on in the LED array driving step. 16. An instruction step for instructing a start of pre-original detection before or after an original is read or at a fixed period, and the LED optical system scans the original in the light source moving step in accordance with the instruction in the instruction step. After returning to the start position, the LE of the LED optical system is driven in the LED array driving step.
A second control step in which the D light emitting element is turned on to start document detection in the detection step; and a notifying step of notifying that a document has been left behind when it is determined in the determination step that a document is present. 16. The image reading method according to claim 15, comprising: 17. In the determining step, when detection data is output in the detection step, an object size is obtained from the detection data, and the size and a predetermined value based on a minimum original size are determined. In comparison, when the size of the object is smaller than the specified value, it is determined that there is dust, and in the notification step, when it is determined that there is dust in the determination step, a notification of “dust is present” is given. 17. The image reading method according to claim 15, wherein the method is performed. 18. If the determination step determines that there is dust, the control step determines the LE in the light source moving step based on a detection result in the detection step.
18. The image reading method according to claim 17, wherein the D optical system is moved to a center position of the dust, and the LED array element driving step turns on an LED light emitting element closest to the center position of the dust. 19. A white LED array in which white LED light emitting elements are arranged in an array in one row, or an LED having a group of LED arrays in which a plurality of the LED arrays are connected in one row.
A recording medium on which a program for controlling a device for reading a document image by irradiating a document on a document table with a scanning light of an optical system by a computer is recorded. Moving the white LED light-emitting elements of the LED array to emit light, and causing a light receiving element to receive reflected light obtained by irradiating the LED optical system with scanning light on a document table on which the original is mounted; Detecting the position of the object on the document table based on the output of the document table, moving the LED optical system to the document position based on the detection result, and turning on the LED light emitting element at the document position. Medium. 20. The program causes a computer to determine the size of an object from the detection result, and compares the size with a predetermined value based on a minimum document size. If it is greater than or equal to a specified value, it is determined that there is a document. If it is determined that there is a document, the LED optical system is moved to the document position based on the detection result, and the LED light emitting element at the document position is moved. 20. The recording medium according to claim 19, wherein is turned on. 21. The program causes a computer to return the LED optical system to a document scanning start position before reading a document, after reading a document, or in a fixed cycle, and then switch the LED light emitting element of the LED optical system. 21. The recording medium according to claim 20, wherein the recording medium is turned on to start document detection, and when it is determined that there is a document, notification of "there is a misplaced document" is made. 22. The program causes a computer to determine the size of an object from the detection result, and compares the size with a predetermined value based on a minimum document size. 22. The recording medium according to claim 20, wherein when it is smaller than a prescribed value, it is determined that there is dust, and when it is determined that there is dust, a notification that "there is dust" is issued. 23. The program, when the computer determines that there is dust, moves the LED optical system to a center position of the dust based on the detection result, and The recording medium according to claim 22, wherein the LED light-emitting element is turned on. 24. An LED having a white LED array in which white LED light emitting elements are arranged in an array in a row, or an LED array in which a plurality of the LED arrays are connected in a row.
A program for controlling, by a computer, a device that reads a document image by irradiating a document on a document table with scanning light of an optical system, wherein: a light source moving step of moving the LED optical system; and An LED array driving step of individually emitting white LED light emitting elements, a light receiving step of receiving a reflected light obtained by irradiating the LED optical system with scanning light on a document table on which the document is mounted, and a light receiving element, A detecting step of detecting a position of the object on the platen based on an output of a light receiving element, and moving the LED optical system to a document position in the light source moving step based on a detection result in the detecting step; A control step of turning on an LED light emitting element at a document position in an LED array driving step. Beam. 25. An object size is determined from the detection data in the detection step, and the size is compared with a predetermined value based on a minimum document size, so that the size of the object is smaller than the specified value. A determining step of determining that there is a document when the document is larger or equal to each other; and in the controlling step, when determining that the document is present in the determining step, the light source moving based on a detection result in the detecting step. 25. The program according to claim 24, wherein the LED optical system is moved to a document position in a step, and the LED light emitting element at the document position is turned on in the LED array driving step. 26. An instruction step for instructing the start of pre-original detection before or after an original is read or at a fixed period, and the LED optical system scans the original in the light source moving step in accordance with the instruction in the instruction step. After returning to the start position, the LE of the LED optical system is driven in the LED array driving step.
A second control step in which the D light-emitting element is turned on to start document detection in the detection step; 26. The program according to claim 25, comprising: 27. In the determination step, when the detection data is output in the detection step, the size of the object is obtained from the detection data, and the size is compared with a predetermined value based on the minimum document size. In comparison, when the size of the object is smaller than the specified value, it is determined that there is dust, and in the notification step, when it is determined that there is dust in the determination step, a notification of “dust is present” is given. The program according to claim 25, wherein the program is executed. 28. When it is determined in the determination step that there is dust, the control step determines the LE in the light source moving step based on a detection result in the detection step.
28. The program according to claim 27, wherein the D optical system is moved to a center position of the dust, and the LED array driving step turns on an LED light emitting element closest to the center position of the dust.