JPH06143682A - Apparatus and method of correcting output of led array - Google Patents

Abstract

PURPOSE:To restrict the influences of the irregularity of the outputting characteristic of light of LED elements in an inexpensive constitution by providing means for correcting the luminous intensity of the entire group of the LED elements to be a specific value, and means for supplying correction data obtained through the correction to a current impressing means. CONSTITUTION:The output data from an image processing part 21 is fed to a gradation correcting part 22. The gradation correcting part 22 corrects the gradation of image data corresponding to the light emitting characteristic of individual LED elements constituting an LED array head 11. The correction data corrected in gradation at the gradation correcting part 22 is fed to a head controller 23 as a current impressing means. The head controller 23 feeds a current corresponding to the correction data to the individual LED elements of the LED array head 11. Accordingly, even when the characteristic of the LED elements constituting the LED array head 11 is irregular, the gradation is correctly expressed corresponding to the image data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in digital copying machines, printers, facsimile machines, etc.
The present invention relates to an apparatus and method for correcting the light output of an LED (light emitting diode) array used for recording an image or the like.

[0002]

2. Description of the Related Art Digital copying machines and printers for forming images by an electrophotographic process are widely used. In these devices, a uniformly charged photoreceptor is exposed with light corresponding to the image to be recorded. As a result, an electrostatic latent image is formed on the surface of the photoconductor. This electrostatic latent image is developed into a toner image, and the toner image is further transferred onto recording paper. Then, the toner transferred onto the recording paper is heated and fixed, thereby forming an image.

Conventionally, a laser beam has been widely used as an exposure light source for forming an electrostatic latent image on a photosensitive member, but in recent years, an LED array head has also been widely used. The LED array head has a plurality of LED elements arranged in a straight line corresponding to each dot of an image to be formed. This LED array head is arranged along the longitudinal direction of a right cylindrical photosensitive member, for example. At the time of image formation, the photoconductor is driven to rotate about its axis. And a plurality of L's of the LED array head
Among the ED elements, the LEDs corresponding to the image to be formed are selectively driven to light. As a result, an electrostatic latent image corresponding to the image to be recorded is formed on the surface of the photoconductor.

LEDs used in digital copiers and the like
In the array head, each LED element is not controlled into two states, that is, a lighting state and a non-lighting state.
The current given to the element takes a discrete value of 32 steps.
Accordingly, one dot can express 32 gradations, and therefore, L can be expressed based on the image data expressed in plural gradations.
By driving the ED array head, it is possible to form a halftone image.

[0005]

However, the plurality of LED elements provided in the LED array head have variations in light emission characteristics even if they are formed on the same chip. That is, even if an equal current is applied to each LED element, a difference occurs in the luminous intensity of each LED element. Therefore, for example, when a halftone image is formed over a relatively wide area, a line extending in a direction intersecting with the arrangement direction of the LED elements is formed, or a certain area is dark and a certain area is thin. There is a problem that unevenness occurs.

More specifically, when an equal current is applied to each LED element to cause an image forming operation according to the electrophotographic process, a slight difference in density occurs between the dots forming the formed image. When the density difference is less than one gradation difference, the density difference cannot be corrected by correcting the image data for each LED element to be given to the LED array head. This is because even if the image data is changed, only the correction for each gradation can be performed.

Therefore, it is conceivable to increase the number of gradations of the current value given to each LED element of the LED array head and simultaneously increase the number of gradations of the image data. That is, if the number of gradations is increased, the current value applied to the LED element can be minutely changed, so that a slight density difference can be corrected. More specifically, the luminous intensity of each LED element that constitutes the LED array head is measured in advance, and the image data corresponding to each LED element is gradation-corrected based on the measurement result, so that the characteristics between the LED elements can be improved. It is sufficient to absorb the variation of.

However, it is difficult to individually measure the luminous intensity of each LED element that constitutes the LED array head, and a drive circuit that can change the current value given to each LED element in multiple stages is not available. It is expensive. Therefore, the above technique is not very practical. Therefore, conventionally, it has been extremely difficult to form a high-quality halftone image in an image forming apparatus using an LED array head.

Therefore, an object of the present invention is to solve the above-mentioned technical problems and to suppress the influence of variations in light output characteristics among a plurality of LED elements with an inexpensive structure, and an output correction device for an LED array, and It is to provide an output correction method.

[0010]

SUMMARY OF THE INVENTION To achieve the above object, an LED array output correcting apparatus of the present invention comprises a plurality of L's.
An LED array in which ED elements are arranged in a predetermined state and a current corresponding to the data expressed in gray scales in a plurality of gray scales are supplied to each LE.
A device for correcting the light output of the LED array, which is applied to a device including a current applying unit for applying to a D element, and is a gray scale with a plurality of gray scales for controlling a current applied to each LED element. The expressed input data is converted into a plurality of LEs described above.
When the input data corresponding to all the LED elements forming each LED element group obtained by dividing the D element into a predetermined number of groups having a close positional relationship are equal, the luminous intensity of the entire LED element group is the input. It is characterized in that it includes means for correcting so as to obtain a predetermined value that should be obtained for the data, and means for giving the correction data obtained by correcting the input data to the current applying means.

Further, according to the LED array output correction method of the present invention, the optical output of an LED array in which a plurality of LED elements to which currents corresponding to data expressed in a plurality of gradations are respectively applied are arranged in a predetermined state. A method of correction,
The plurality of LED elements are divided into a predetermined number of LED element groups having a close positional relationship, and a current corresponding to a predetermined gradation data is commonly applied to the predetermined number of LED elements forming the LED element group. LED when
The luminous intensity of the entire element group is measured for each LED element group, and based on the measurement result, the input data represented by a plurality of gradations for controlling the current applied to each LED element All LEs that make up the group
LED when the input data corresponding to the D element is equal
It is characterized in that the luminous intensity of the entire element is corrected so as to take a predetermined value that should be obtained for the input data, and a current corresponding to the correction data obtained by this correction is given to each LED element.

[0012]

First, the principle of the present invention will be described with reference to Table 1 below.

[0013]

[Table 1]

As a premise of the description, in an ideal LED array, for example, four LEDs arranged close to each other are used.
When a current with a current value of "1" is applied to the element, the luminous intensity of each LED element takes a value of "0.300" and the four LEDs
Assume that the total luminous intensity of the group of elements is "0.300". This luminous intensity "0.300" is used as a reference value.

On the other hand, in the actual LED array, the light emitting characteristics of the LED elements vary. Therefore, when a current having a current value "1" is applied to the first to fourth LED elements,
For example, the luminous intensities of the first and fourth LED elements are “0.300” which is equal to the reference value, but the luminous intensities of the second LED element are “0.270” and the luminous intensities of the third LED element are “0”. .250 ”. This state is the “before correction” state in Table 1.

In this case, if the current value given to the third LED element is corrected to "2", the luminous intensity of this third LED element becomes, for example, "0.350" (the "corrected" state in Table 1). See.). That is, when the current value is changed by one gradation, the luminous intensity changes by "0.1", for example. Therefore, when attention is paid only to the third LED element, its luminous intensity cannot be corrected to the reference value "0.300".

However, paying attention to the overall luminous intensities of the first to fourth LED elements, the current value of the third LED element is corrected to "2", so that "0.3" equal to the reference value is obtained.
A luminosity of "00" is achieved. That is, each LE
In order to correct the luminosity of the D element to the reference value, the step width of the current value given to each LED element must be made small, but the luminosity of the groups of the first to fourth LED elements is corrected to the reference value. Therefore, it is not necessary to make the step width of the current value given to each LED element minute. That is, in the four LED element groups, by changing the current value given to each LED element in units of one gradation, it is possible to make the gradation different for each quarter gradation as a whole.

Therefore, according to the present invention, the plurality of LED elements included in the LED array are divided into a predetermined number of LED element groups which are in close proximity to each other. And L
The luminous intensity of the entire LED element group when a current corresponding to the data of the predetermined gradation is commonly applied to the predetermined number of LED elements forming the ED element group is measured for each LED element group. Based on this measurement result, LED
When the input data corresponding to all the LED elements forming the element group are equal, the gradation of the input data is corrected so that the luminous intensity of the entire LED element has a predetermined value that should be obtained for the input data. Is added. The current corresponding to the correction data obtained by this correction is L
It is given to the ED element.

As a result, a desired luminous intensity can be achieved for the entire LED element group. So, for example, LE
When the D array is used as a light source for image formation, it is possible to excellently form a halftone image over a relatively large area.

[0020]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 2 is a sectional view showing a simplified internal structure of a digital copying machine to which an embodiment of the present invention is applied. An image scanner 2 is arranged on the lower surface side of the transparent document placing table 1.
Is reciprocated in the directions of arrows 3 and 4 by a drive mechanism (not shown). The document 5 placed on the document table 1 is illuminated and scanned when the image scanner 2 is displaced in the direction of arrow 3, for example, and the image on the surface thereof is read.

The image scanner 2 includes a light source 6 for illuminating the original 5, a one-dimensional image sensor 7 for receiving scattered light from the original 5, and a scattered light from the original 5 to the image sensor 7 to guide the image. The document 5 is placed on the light receiving surface of the sensor 7.
And a lens 8 for forming the image. The output signal of the image sensor 7 is given to the signal processing unit 9. The signal processing unit 9 performs predetermined image processing on the output signal of the image sensor 7 to create a control signal to be given to the LED array head 11.

The LED array head 11 is used as an exposure light source for exposing the right cylindrical photosensitive member 12 in the image forming section 10 which performs an image forming operation by an electrophotographic process. The LED array head 11 has a plurality of LED elements (not shown) arranged along the longitudinal direction of the photoconductor 12. Each LED element corresponds to one dot of the image to be formed. The plurality of LED elements are driven to emit light corresponding to an image to be formed by a control signal from the signal processing unit 9.

The photosensitive member 12 is rotated at a constant speed in the direction of arrow 13 around its axis by a structure not shown. A charger 14 that uniformly charges the surface of the photoconductor 12 is provided at a position upstream of the LED array head 11 with respect to the arrow 13. When the uniformly charged surface of the photoconductor 12 is exposed by the LED array head 11, the charge on the surface is selectively removed, and as a result, the photoconductor 12 is exposed.
An electrostatic latent image corresponding to the original image is formed on the surface of the.

The electrostatic latent image is developed into a toner image by the developing device 15. Then, this toner image is transferred to the recording paper 17 in the transfer device 16. The recording paper 17 on which the toner image is transferred is fixed to the fixing device 19 by the conveyor belt 18.
And is subjected to heating and fixing processing of toner. The toner remaining on the surface of the photoconductor 12 after the toner image is transferred to the recording paper 17 is removed by the cleaning device 20 and prepared for the next image formation.

FIG. 1 is a block diagram showing a part of the configuration of a signal processing section 9 for producing a control signal to be given to the LED array head 11. The image sensor 7 reads an image for each predetermined dot. Then, the output signal corresponding to each dot is converted by the image processing unit 21 into image data represented by gradations of 32 gradations consisting of 5-bit data, for example. The image processing unit 21 performs contour enhancement processing and other processing on the image data.

The output data of the image processing unit 21 is given to the gradation correction unit 22. The gradation correction unit 22 performs gradation correction on the image data according to the light emission characteristics of the individual LED elements that form the LED array head 11. The correction data subjected to the gradation correction by the gradation correction unit 22 is given to the head controller 23 which is a current applying unit. The head controller 23 sets the current corresponding to the correction data to L
It is given to each LED element of the ED array head 11. As a result, accurate gradation expression corresponding to image data can be performed without depending on variations in characteristics of the LED elements forming the LED array head 11.

The gradation correction unit 22 is composed of, for example, an SRAM (static random access memory). In this SRAM, there are a plurality of sets (for example, 16 sets) of correction data composed of 32 pieces of correction data corresponding to respective data of 32 gradations given from the image processing unit 21.
It is remembered. A selection signal for selecting this set of correction data is given from the dot data storage unit 24. The dot data storage unit 24 is used for the LED array head 1
Information indicating which set of correction data is selected corresponding to each LED element configuring 1 (hereinafter, this information is referred to as “dot data”) is stored.
The dot data storage unit 24 is composed of, for example, a ROM (read only memory).

The dot data storage unit 24 includes a control unit 30.
The output of the counter 25 which is controlled by and performs the counting operation is given. As a result, the dot data relating to each LED element forming the LED array head 11 is sequentially supplied from the dot data storage section 24 to the gradation correction section 22. Therefore, the gradation correction unit 22 switches the correction data set for each dot, and outputs the correction data corresponding to the input image data in the selected correction data set.

The control unit 30 also controls the image processing unit 21 and the head controller 23. Thereby, each processing in the image processing unit 21, the gradation correction unit 22 and the head controller 23 can be synchronized.
Table 2 below shows the contents of the data correction table provided in the gradation correction unit 22. The correction data is selected by the dot data provided from the dot data storage unit 24 and the image data provided from the image processing unit 21. The symbol “H” added to the end of the number indicates that the number before it is a hexadecimal number.

[0030]

[Table 2]

The dot data is, for example, 4 bits,
The image data is, for example, 5 bits. Therefore, 32
Sixteen sets of 32 correction data corresponding to each gradation of the image data (00H to 1FH) expressed in gradation are prepared. For example, when the gradation correction unit 22 is composed of an SRAM, an address in which the dot data is the upper 4 bits and the image data is the lower 5 bits is given to the SRAM, and the correction data written in the address is read out. Gradation correction is achieved. Specifically, the dot data is "05H" and the image data is "0AH".
If so, the correction data is “0DH”.

The 32 correction data corresponding to each dot data are set so that the current applied to the LED element increases linearly as the image data increases.
This is because the light intensity of the LED element increases linearly as the input current increases. FIG. 3 is a diagram for explaining the content of the dot data stored in the dot data storage unit 24, and LED elements e10, e11, e12, ..., E19; e20, provided in the LED array head 11. e
The arrangement state of 21, ..., E29; e30, e31, .. (hereinafter, collectively referred to as "LED element e") is shown in a simplified manner. In determining the data to be written in the dot data storage section 24, the luminous intensity of the LED array head 11 is checked with the LED array head 11 removed from the main body of the digital copying machine.

In more detail, a plurality of LEDs
The element e is a continuous LED element group G of 10 pieces.
1, G2, G3, ... (Hereinafter, when collectively referred to, "LE
D element group G ". ) Is divided into. And
Common data "06H" for all LED elements e
Is given to the head controller 23, and the luminous intensity is measured for each LED element group G. That is, each LE
The light intensity is not measured for each D element e, but the light intensity is measured for each LED element group G including 10 LED elements e. Based on this measurement result, the difference between the data “06H” and the reference luminous intensity that should be originally obtained is calculated.

Table 3 below shows an example of measured values of luminous intensity for each LED element group G and numerical values obtained by calculating the difference between each measured value and the reference luminous intensity. In Table 3, the reference luminous intensity is 0.690 (μW). That is, the luminous intensity of the LED element e is 0.690 with respect to the data “06H”.
If it is (μW), good gradation expression can be achieved. In addition, LE
Since the D element groups G1 to G5 are located in the non-image area, the calculation of the difference between the reference luminous intensity and the measured value is omitted for them.

[0035]

[Table 3]

When the difference between the reference luminous intensity and the luminous intensity of the LED element group is obtained in this way, the dot data for each LED element e is determined based on the value of the difference. Table 4 below is a table for explaining a determination method for determining the dot data of each LED element e based on the difference between the luminous intensity measured for each LED element group G and the reference luminous intensity.

[0037]

[Table 4]

A difference of one gradation in image density corresponds to a difference of luminous intensity of 0.115 (μW), for example. Therefore,
When the image data corresponding to the LED element e is changed by one gradation, the luminous intensity of each LED element e changes by 0.115 (μW). On the other hand, LE consisting of 10 LED elements e
When considering the D element group G as a unit, the individual L
Since the gradation of the ED element can be changed step by step, the gradation can be expressed with a resolution of 10 times that of the ten LED elements e as a whole. That is, the luminous intensity can be changed in 0.1 gradation steps.

Therefore, in the present embodiment, with reference to the case where the difference between the reference luminous intensity and the measured luminous intensity is "0", the gradation difference is "-0.7" to "1. The dot data is made different within the range of "5". Since the difference of 0.1 gradation corresponds to the difference of luminous intensity 0.0115 (μW), the reference value of the difference between the reference luminous intensity and the measured value corresponding to each gradation difference is 0.0115 (μW). Takes a value.

On the other hand, since the difference between the reference luminous intensity and the measured luminous intensity is obtained for each group G of 10 LED elements e, dot data corresponding to 10 LED elements e is determined for each gradation difference. . That is, for example, the gradation difference “0.
2 ”, 10 dot data“ 5FFFF5 ”
FFFF "is defined. Each dot data is each L
It corresponds to the individual LED elements e forming the ED element group G.

For example, the LED element group G22 will be taken as an example. The luminous intensity of this group G22 is 0.663 (μW) as can be seen from Table 3, and the difference from the reference luminous intensity is
It is −0.027 (μW). In Table 4, the reference value of the difference from the reference luminous intensity is closest to -0.027 (μW) when the gradation difference is "-0.2". Therefore, for the LED element group G22, the gradation difference "-
Dot data “EFFFEFFFF” corresponding to 0.2 ”
F "is selected. That is, the LED element group G2
The dot data of the first and fifth LED elements e out of the 10 LED elements e constituting 2 is set to “EH”, and the second to fourth and sixth to tenth
The th dot data is set to “FH”.

The dot data for each LED element e as described above is written in the ROM constituting the dot data storage section 24. The dot data in Table 4 is the LED element group G
When the image data corresponding to all the LED elements e constituting the LED are all equal, the head controller 23 supplies a current to the LED element group G so that the entire luminous intensity of the LED element group G becomes a predetermined luminous intensity to be obtained for the image data. It is set so that it can be applied to the array head 11. That is, if the dot data is set according to Table 4, the correction data output from the gradation correction unit 22 is given to the head controller 23 so that the luminous intensity of the LED element group G corresponds to the image data from the image processing unit 21. It can be any desired value.

At the time of image formation, the dot data of each LED element e is given to the gradation correction section 22. Then, the first and fifth LED elements e of the group G22
For 32, a set of 32 correction data corresponding to the dot data “EH” is selected, and for the second to fourth and sixth to tenth LED elements E, it corresponds to the dot data “FH”. The 32 correction data sets that have been selected are selected.

As a result, when all the image data corresponding to the LED elements e forming the LED element group G22 is, for example, "0DH", by referring to Table 2, the first through the first elements forming this group G22 are referred to. It is understood that the correction data corresponding to the tenth LED element e is as follows. 1st ・ ・ ・ ・ ・ ・ 0EH 2nd ・ ・ ・ ・ ・ ・ ・ ・ 0DH 3rd ・ ・ ・ ・ ・ ・ 0DH 4th ・ ・ ・ ・ ・ ・ 0DH 5th・ ・ ・ ・ ・ ・ 0EH 6th ・ ・ ・ ・ ・ ・ 0DH 7th ・ ・ ・ ・ ・ ・ 0DH 8th ・ ・ ・ ・ ・ ・ 0DH 9th ・..... 0DH 10th ..... 0DH As a result, the luminosity of each LED element e forming the LED element group G22 is not always a value that accurately reproduces the data "0DH". Without LED element group G2
The luminosity of 2 as a whole is a value with which the image density to be obtained for the data 0DH can be reproduced extremely accurately.

As described above, according to this embodiment, the plurality of LED elements e constituting the LED array head 11 are grouped into 10 LED element groups G. Then, a current corresponding to data of a predetermined gradation (for example, "06H") is commonly applied to each LED element e, and the luminous intensity of each LED element group G at that time is measured. Further, the difference between the measured luminous intensity and the reference luminous intensity is obtained. Based on this difference, dot data corresponding to each LED element e is determined so that the luminous intensity of each LED element group G has a desired value as a whole.

When the gradation correction processing is performed by the gradation correction unit 21 based on the dot data thus determined, when the image data corresponding to all the LED elements e forming the LED element group G are equal to each other. , The total luminous intensity of the LED element group G becomes a desired value to be obtained for the image data. In this way, individual LEs
Instead of slightly changing the current for each D element e, each LE
The step width of the current supplied to the D element e is 10
The luminous intensity of the group G of the individual LED elements e can take a desired value as a whole. As a result, for example, when a halftone image is to be formed over a relatively large area,
A good halftone image can be formed without causing undesired lines and uneven density. That is, it is possible to effectively eliminate the influence of variations in the light emission characteristics of the individual LED elements e.

In this way, a halftone image can be satisfactorily formed without the need for an expensive drive circuit for minutely changing the current supplied to the LED element e. Further, since the luminous intensity of the LED array head 11 is measured for each group of 10 LED elements e, the individual LE
There is no technical difficulty as in the case of detecting the luminous intensity of the D element e.

Further, since variations in the light emitting characteristics of the LED elements e constituting the LED array head 11 can be easily corrected, conversely, large variations in the characteristics of the LED elements e in the LED array head 11 may occur. Therefore, the LED array head 11 applied to the image forming apparatus
There is no need to select chips having a plurality of LED elements when configuring the above. In addition, the drive circuit applied to the head controller 23 is also the same.
A certain degree of characteristic variation is allowed. This is
It also leads to an improvement in yield when manufacturing the LED array head and the drive circuit.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. For example, in the above-described embodiment, the image data is corrected so that the luminous intensity of the group of 10 LED elements e becomes the desired value, but the luminous intensity of, for example, about 4 LED element groups becomes the desired value. Such correction may be performed. Generally, L that constitutes one LED element group
It is preferable that the number of ED elements is selected so that the luminous intensity can be easily measured and that the area covers a sufficiently small area for the size of an image to be formed. In particular,
It is preferable to select about 4 to 10.

In the above embodiment, the image data is 5
Although it is considered as a bit and the dot data is 4 bits,
The number of bits of each data may be set arbitrarily as needed. Further, although the above embodiments have been described by taking a digital copying machine as an example, the present invention is widely applicable to a device in which an LED array head may be used for forming an image, such as a facsimile device. It is also applicable to LED arrays used for purposes other than image formation.

In addition, various design changes can be made without changing the gist of the present invention.

[0052]

As described above, according to the present invention, the luminous intensity of the entire LED element group including a predetermined number of LED elements becomes a desired value corresponding to the input data. This makes it possible to favorably suppress the influence of variations in the light emission characteristics of the individual LED elements. Moreover, since an expensive drive circuit for minutely changing the current applied to each LED element is not required, the light output of the LED array can be favorably corrected with an inexpensive configuration.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of a digital copying machine to which an embodiment of the present invention is applied.

FIG. 2 is a sectional view showing a simplified internal configuration of the digital copying machine.

FIG. 3 is a diagram for explaining grouping of LED elements included in an LED array head.

[Explanation of symbols]

2 image scanner 9 signal processing unit 10 image forming unit 11 LED array head 12 photoconductor 21 image processing unit 22 gradation correction unit 23 head controller 24 dot data storage unit 25 counter 30 control unit G1, G2, G3, ... LED element group e10, e11, ..., e19; e20, e21, ..., e29; e30, ... LED
element

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location G03G 15/04 116 H04N 1/036 A 8721-5C

Claims (2)

[Claims] 1. An apparatus comprising: an LED array in which a plurality of LED elements are aligned in a predetermined state; and a current applying means for applying a current corresponding to data expressed in a plurality of gradations to each LED element. A device for correcting the light output of the LED array, wherein input data represented by a plurality of gradations for controlling an applied current to each LED element is applied to the plurality of LED elements. When the input data corresponding to all the LED elements constituting each LED element group obtained by dividing into a predetermined number of groups having a close positional relationship are equal, the luminous intensity of the entire LED element group is relative to the input data. And a means for applying correction data obtained by correcting the input data to the current applying means. LE
Output correction device for D array. 2. A method for correcting the light output of an LED array in which a plurality of LED elements to which currents corresponding to data expressed in a plurality of gradations are respectively applied are arranged in a predetermined state. The LEDs are divided into a predetermined number of LED element groups in close proximity to each other, and the predetermined number of LED elements forming the LED element group are commonly supplied with a current corresponding to data of a predetermined gradation. The luminosity of the entire element group is measured for each LED element group, and based on the measurement result, the input data represented by a plurality of gradations for controlling the current applied to each LED element is input to the LED element. When the input data corresponding to all the LED elements forming the group are equal, the luminosity of the entire LED element has a predetermined value to be obtained for the input data. Corrected to so that the output correcting method of the LED array, characterized in that providing a current corresponding to the correction data obtained by the correction in the LED elements.