JP2004299112A - Image formation device and image formation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To correctly carry out preparatory arrangements for production operation such as density unevenness correction and setup, in a short time. <P>SOLUTION: According to an image formation device 100, two processes of the density unevenness correction and the setup can be carried out in parallel for correctly executing the preparatory arrangements for the production operation of the density unevenness correction and the setup in a short time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus and an image forming method.
[0002]
[Prior art]
2. Description of the Related Art Recently, with the spread of digital cameras, there is a great demand for improvement of performance such as printing ability and image quality of a digital minilab machine as an image forming apparatus. In particular, there is a high demand for large-format printing, and many developments of an exposure engine using a print head in which a plurality of light-emitting recording elements (hereinafter, referred to as recording elements) suitable for this are arranged in an array have been reported. .
[0003]
Generally, the above-mentioned recording elements have variations in individual light emission characteristics. If the variation is insufficiently corrected, the variation will be recorded as it is as the density unevenness of the image at the time of fprint making, and the commercial value of the digital output image will be greatly impaired.
[0004]
Individual recording elements usually have a variation of about 20% to 40%, and when attempting to reproduce a photograph or the like in continuous tone, at least 2% or less, and 1% or less for higher quality. It is necessary to correct the variation. Techniques related to this correction are disclosed in Patent Documents 1 and 2, and the like.
[0005]
On the other hand, in order to obtain a high-quality output image, it is necessary to individually adjust the RGB color balance, which is the basic color. For this reason, a technique for adjusting the light emission amount of a print head in which recording elements are arranged in an array is disclosed in Patent Document 3 or the like.
[0006]
In order to obtain high-quality output images, adjust the light intensity correction coefficient of each recording element to reduce the variation before the full-scale operation of the digital mini-lab machine, usually in the morning (density unevenness correction). In addition, adjusting the color balance by adjusting the exposure amount (setup) is essential as advance preparation.
[0007]
[Patent Document 1]
JP-A-8-230235
[Patent Document 2]
JP-A-10-811
[Patent Document 3]
JP-A-10-75377
[0008]
[Problems to be solved by the invention]
By using the above-described conventional technique, density unevenness correction is improved, and setup is possible. However, only the above-described conventional technique requires that the two steps of density unevenness correction and setup be performed separately.
[0009]
In addition, since density unevenness correction is often performed by adjusting the amount of light emitted from each light emitting element of the print head, a subtle change in color balance may occur after density unevenness correction. In order to correct this, it is necessary to always perform setup after density unevenness correction.
[0010]
However, the above-described two steps are usually performed by repeatedly feeding back the density information obtained based on the output image. Therefore, 1) density unevenness correction image output, 2) density unevenness correction calculation, 3) correction calculation feedback, The process of 4) image output for setup, 5) setup calculation, 6) setup calculation feedback, etc., is followed, and a great deal of time is required for preparations before the full-scale operation of an image forming apparatus such as a digital minilab machine.
[0011]
Furthermore, if density unevenness occurs for some reason during operation of an image forming apparatus such as a digital minilab machine, the image output of the digital minilab machine will take a long time because it is necessary to perform not only the density unevenness correction but also the setup again. Is impossible. Many minilab stores today often use short-time finishing as their selling point, and this situation not only reduces production efficiency but also fails to meet the promised time with customers, causing the minilab store to lose credit. Is of great concern.
[0012]
On the other hand, the density to be set up is a density that is frequently used in an output image. Since it is preferable to perform density unevenness correction in a density region where usage is high, it is more preferable to perform density unevenness correction after performing setup. For this reason, the repetition of the above two steps continues, and it is unclear when the preparation is completed. In recent years, relatively inexperienced operators such as part-time workers tend to operate at minilab stores, and it is necessary to let them judge the completion of advance preparation to obtain high quality output images, but this is very Difficult.
[0013]
It is impossible to find a solution to these problems only with the conventional technology described above, and considering the recent situation of minilab stores, it is difficult to produce a digital minilab machine that can be put to practical use only with the conventional technology. Have difficulty.
[0014]
SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus and an image forming method in which preparations for full-scale operation are completed in a short time and excellent density unevenness correction can be performed.
[0015]
[Means for Solving the Problems]
In order to solve the above problems, the invention described in claim 1 is
A print head in which a plurality of recording elements each operating based on an individual light amount correction coefficient are arranged in an array,
An image reading device that reads an image recorded on a photosensitive material,
The correction image is recorded on the photosensitive material using the print head, the read information of the recorded correction image is obtained via the image reading device, and the recording of each of the recording elements is performed based on the obtained read information. A correction processing unit that obtains a correction amount for the characteristic, and corrects the light amount correction coefficient using the obtained correction amount;
With
In an image forming apparatus that records an image using each of the recording elements based on the light amount correction coefficient corrected by the correction processing unit,
The exposure amount information is obtained based on the read information obtained from the correction image.
[0016]
Further, in order to solve the above problem, the invention according to claim 13 is as follows.
A correction image recording step of recording a correction image on a photosensitive material using a print head in which a plurality of recording elements each operating based on an individual light amount correction coefficient are arranged in an array, and A read information acquisition step of acquiring read information via an image reading device; a correction amount acquisition step of acquiring a correction amount for a recording characteristic of each of the recording elements based on the acquired read information; and A correction step of correcting the light quantity correction coefficient using an image recording step of recording an image using each of the recording elements based on the corrected light quantity correction coefficient.
The method further includes an exposure amount information acquiring step of acquiring exposure amount information based on the read information acquired from the correction image.
[0017]
With the above configuration, the light amount correction coefficient of each of the recording elements arranged in an array on the print head is adjusted to reduce variations in the recording elements (that is, density unevenness correction), and the exposure amount is adjusted. And individually adjusting the color balance (that is, setup) at the same time, the preparation for full-scale operation of an image forming apparatus such as a mini lab machine can be completed in a short time, and a favorable Density unevenness correction can be performed.
[0018]
Since the two steps of density unevenness correction and setup are completed using the same correction image, the time required for image output and the image reading time by an image reading device such as a flatbed scanner can be omitted.
[0019]
In addition, the density unevenness can be greatly reduced in the density area where the frequency of use is high, that is, in the density area where the setup is performed, or an extremely high-quality output image can be obtained.
[0020]
The read information in the present invention means information indicating an optical density obtained as a result of image measurement, and may be the density itself, but may be a reflectance, a transmittance, a light absorption, or the like, or one-to-one correspondence with these. Function value, for example, a logarithmic value. When an image is read by an image reading device such as a flatbed scanner and measurement is performed, a signal value measured by the image reading device may be used, and a function value corresponding to the above-described signal value one-to-one, For example, it may be a logarithmic value or a relative value thereof. Further, the read information in the present invention may be called density information or simply density.
[0021]
The exposure amount information in the present invention is information on the exposure amount given to the recording photosensitive material when an image is recorded on the recording photosensitive material, and may be the exposure amount itself given to the photosensitive material, or may be a pair with the aforementioned exposure amount. One corresponding function value, for example, a logarithmic value, or a relative value thereof may be used. It is preferable that the above-mentioned exposure amount information corresponding to each array print head exists.
[0022]
In addition, it is preferable to output an image in consideration of the light amount correction coefficient and the exposure amount information with respect to the image information, whereby a high quality output image can be obtained.
[0023]
In the present invention, the setup for individually adjusting the color balance is preferably performed by appropriately adjusting the amount of light emitted by each print head to the photosensitive material, but may be in any form. As an example of a preferable mode of the setup, when a signal value for setup which is a density region having a high frequency of use is previously selected and recorded on a photosensitive material by image information based on the selected signal value, a desired density can be obtained. In this case, the exposure amount information is appropriately adjusted.
[0024]
FIGS. 16A to 16C are schematic diagrams showing print heads arranged in an array.
The array shape is not limited to a linear shape as shown in FIG. 16A, but also includes a staggered array as shown in FIG. 16B and an array as shown in FIG. 16C. Further, as shown in the drawing, each printing element is numbered, and the printing elements adjacent to each other in the arrangement direction of the printing elements correspond to the printing elements whose numbers are adjacent.
[0025]
Here, the arrangement direction of the recording elements means the direction in which more recording elements are arranged as shown in FIGS. 16 (a) to 16 (c).
[0026]
When a rectangular image for correction is set in the image reading device, it is necessary to make the non-short sides of the rectangle overlap in the arrangement direction of the light receiving elements (CCDs) of the image reading device. It is preferable from the viewpoint of.
[0027]
Printheads arranged in an array may be any in which a plurality of recording elements are arranged in one or more rows at predetermined intervals in order to obtain a desired resolution. As a preferred example of a printhead arranged in an array, An array of LED light emitting elements and vacuum fluorescent tubes, a PLZT print head using an appropriate backlight, an optical shutter array such as a liquid crystal shutter array print head, an array of semiconductor lasers, a thermal head, an organic EL material And a light-emitting element utilizing the electroluminescence phenomenon. Further, an apparatus capable of forming an image of a plurality of gradations, such as an apparatus for recording on a silver halide photosensitive material using various recording element arrays and an apparatus for recording with a thermal head using sublimable ink, is particularly preferable.
[0028]
Here, the image may be an image in which pixel intervals of at least one recording element or more are formed in the recording element direction and pixels are discrete, but it is preferable that the image is a solid image with no pixel interval. . Further, any image may be used as long as it is solid, but it is preferable that the density be as uniform as possible in the recording element direction. Further, those used mainly for correcting density unevenness of the print head are preferable.
[0029]
In the case where the photosensitive material is recorded after cutting, regarding the size of the photosensitive material on which an image is recorded, the length (LV) in the direction perpendicular to the recording element arrangement direction of the print head is the length in the recording element arrangement direction of the print head. (L / LH) is preferably not too long, and from the viewpoints of transportability of photosensitive material, reduction of loss paper, and effects on development processing, LV / LH is preferably within 2.0 times, and 1.2 times or less. Is more preferably, and more preferably 0.9 times.
[0030]
The correction amount is for adjusting the light amount correction coefficient of each recording element so that each recording element can record on the photosensitive material with a uniform light emission amount.
[0031]
The light amount correction coefficient in the present invention is a coefficient for controlling the light emission amount of each recording element, and it is preferable to control the light emission amount by controlling the light emission time, for example. Here, each recording element may have an individual light amount correction coefficient.
[0032]
As a preferable purpose when using the light quantity correction coefficient, firstly, it is necessary to reduce a variation in light emission of individual recording elements to obtain a uniform light emission quantity. As a preferable means for obtaining a uniform light emission amount, adjustment may be made by comparing the average value of the light emission amounts of the recording elements within a desired range with the light emission amounts of the individual recording elements. Secondly, a preferable purpose of using the light amount correction coefficient is to adjust the color balance of each print head. A preferable means for adjusting the color balance is to adjust the average value of the light emission amounts of the recording elements within a desired range so as to obtain a desired density.
[0033]
The light quantity correction coefficient in the present invention may be used for purposes other than those described above, but is preferably used for the first purpose in order to perform accurate density unevenness correction.
[0034]
Further, it is preferable to correct the light amount correction coefficient using the correction amount corresponding to each recording element. It is preferable to sufficiently adjust the light quantity correction coefficient of the print head with an accurate correction amount, so that a uniform solid image can be obtained.
[0035]
The density unevenness correction of the above configuration is preferably performed simultaneously on the same image, and is preferably performed simultaneously using the same image for the purpose of density unevenness correction.
[0036]
Further, like the invention according to claim 2, in the invention according to claim 1,
It is preferable to calculate a statistic related to the read information and obtain the exposure amount information using the calculated statistic.
Like the invention according to claim 14, in the invention according to claim 13,
Preferably, a statistic related to the read information is calculated, and the exposure amount information is obtained using the calculated statistic.
[0037]
According to the above configuration, it is possible to easily obtain exposure amount information from density information (read information). Obtaining the exposure information by using the statistics of the density information indicating the properties of the entire density information eliminates the need to obtain the exposure information for each recording element of the print head, greatly reducing complicated processing. Become.
[0038]
Here, the statistic is preferably a numerical value that indicates the characteristics of the entire distribution with one numerical value, such as an average value, a median, a quartile deviation, a mode, and a root mean square.
[0039]
Further, like the invention according to claim 3, in the invention according to claim 1 or 2,
It is preferable to record on a photosensitive material using the light amount correction coefficient and the exposure amount information independently of each other,
Like the invention according to claim 15, in the invention according to claim 13 or 14,
It is preferable that recording is performed on a photosensitive material using the light amount correction coefficient and the exposure amount information independently of each other.
[0040]
With the above configuration, the light amount correction coefficient of the print head and the exposure amount information become mutually independent information, and it is possible to stably obtain a high-quality output image for a long period of time.
[0041]
Regarding the independence here, the light amount correction coefficient is used only for the purpose of reducing the density unevenness of each recording element of the array print head, and the exposure amount information is used only for the purpose of adjusting the color balance of each basic color. Is preferred.
[0042]
For example, a printhead that emits much more light than the average amount of light or a printhead that has a short life and a reduced amount of light is used. If the light amount correction coefficient and the exposure amount information are not independent when the processing is repeated many times, the average value of the light amount correction coefficient may be extremely large or small. In such a case, the desired light emission time cannot be obtained because, for example, it is not possible to transfer sufficiently accurate data, or it may not be possible to follow the response at the start of driving the print head. There is a possibility that a situation where the accuracy of the unevenness correction is reduced may occur. Therefore, in the present invention, it is preferable that the light amount correction coefficient and the exposure amount information be mutually independent information.
[0043]
Further, like the invention according to claim 4, in the invention according to any one of claims 1 to 3,
It is preferable that the value indicated by the read information obtained from the correction image is set in a linear portion of the characteristic curve of the photosensitive material,
Like the invention according to claim 16, in the invention according to any one of claims 13 to 15,
It is preferable that a value indicated by the read information acquired from the correction image is set in a linear portion of the characteristic curve of the photosensitive material.
[0044]
With the above configuration, density unevenness correction based on density information (read information) and setup accuracy are further improved. The use of the portion where the gradation characteristic changes to a high contrast (that is, the linear portion of the characteristic curve) makes it possible to express a relatively large change in the density of the image due to the variation in the exposure amount of the print head. Therefore, the grasp of the density information becomes accurate, and the accuracy of the density unevenness correction and the setup is remarkably improved.
[0045]
Here, the portion where the gradation characteristic changes to a high contrast corresponds to a straight line portion indicated by a reference symbol A in FIG.
[0046]
Further, like the invention according to claim 5, in the invention according to any one of claims 1 to 4,
The correction image is recorded in a plurality of different recording areas on the photosensitive material surface, read information is obtained from each of the correction images recorded in the plurality of recording areas, and the exposure is performed based on the obtained read information. It is preferable to obtain quantity information,
Like the invention according to claim 17, in the invention according to any one of claims 13 to 14,
The correction image is recorded in a plurality of different recording areas on the photosensitive material surface, read information is obtained from each of the correction images recorded in the plurality of recording areas, and the exposure is performed based on the obtained read information. Preferably, quantity information is obtained.
[0047]
With the above configuration, the obtained density information (read information) becomes more accurate, and density unevenness correction is dramatically improved. Since unevenness such as coating unevenness at a singular point of the photosensitive material can be eliminated, more accurate density information can be obtained without complicating the apparatus and increasing the cost.
[0048]
The image recorded in at least two areas is preferably an image recorded by emitting light from all recording elements, but may be an image divided into two or more locations and emitted by emitting all pixels. Further, the images recorded in at least two areas may be close to each other or may be separated from each other.
[0049]
Further, like the invention according to claim 6, in the invention according to claim 5,
For each of the plurality of recording areas, it is preferable to record correction images at different densities,
Like the invention of claim 18, in the invention of claim 17,
It is preferable to record correction images at different densities in each of the plurality of recording areas.
[0050]
With the above configuration, density information (read information) can be more accurately grasped, so that density unevenness correction and setup can be realized.
It is preferable that recording is performed on the photosensitive material for each of a plurality of areas by input or output signal values based on different image information so that the densities are different from each other.
[0051]
By using images recorded at different densities in at least two areas, it is possible to analyze the correlation between the images and the obtained density information, and to grasp the density information more accurately.
[0052]
Here, the signal value selected for the setup described in the description of the configuration of the first aspect is based on the output conversion LUT (Look Up) based on the basic image information of different densities recorded in the at least two areas. It is preferably included in the range of the output signal value after the conversion in Table).
[0053]
When recording images in three different areas, it is preferable to record three types of images separately for each of the three areas.
[0054]
When recording images in different N regions, it is preferable to record as many different images as possible separately for each N region, and it is more preferable to record N types of images separately for each N region. preferable.
[0055]
Further, it is preferable that the number of recording areas of an image based on different density information is larger. That is, it is preferable that images based on different density information be recorded in many areas. This increases the possibility that interpolation can be performed even when the density target value deviates significantly. If the target value is out of the density range of the recorded image, the signal value may be obtained by extrapolating the relationship of "Log (output value) -density information".
[0056]
Further, according to the configuration of the present invention, a simple set-up is possible even when a plurality of different types of photosensitive materials such as a different lot of photosensitive materials are used.
[0057]
If the photosensitive material to be used includes a substantially linear portion in the characteristic curve, accurate setup can be realized by using the substantially linear portion.
[0058]
Further, like the invention according to claim 7, in the invention according to any one of claims 1 to 6,
The image reading device preferably includes a pressing member for fixing the correction image to the image reading device,
Like the invention according to claim 19, in the invention according to any one of claims 13 to 18,
It is preferable that the correction image is held by using a pressing member in the image reading device.
[0059]
According to the above configuration, the edge determination with respect to the photosensitive material edge can be accurately performed, and the accuracy of density unevenness correction is greatly improved.
[0060]
Further, since floating and bending due to curling of the photosensitive material can be prevented, unevenness of density, particularly unevenness of low frequency components, is greatly reduced.
[0061]
The pressing member here is a member for pressing an image for correction. This pressing member is preferably, for example, black and has a substantially uniform density. Further, as a material of the pressing member, for example, it is preferable that the pressing member is a flexible member such as rubber or sponge. Further, it is preferable that the material is low in static electricity generation and low in chargeability so that dust and dust do not adhere to the pressing member.
[0062]
Further, like the invention according to claim 8, in the invention according to any one of claims 1 to 7,
Preferably, the correction image is recorded on a photosensitive material made of silver halide,
Like the invention according to claim 20, in the invention according to any one of claims 13 to 19,
It is preferable to record the correction image on a light-sensitive material made of silver halide.
[0063]
With the above configuration, the effects of the present invention can be further exhibited.
[0064]
Furthermore, as in the invention according to claim 9, in the invention according to any one of claims 1 to 8,
It is preferable to record the correction image on a photosensitive material having a reflective support,
Like the invention according to claim 21, in the invention according to any one of claims 13 to 20,
It is preferable to record the correction image on a photosensitive material having a reflective support.
[0065]
With the above configuration, the effects of the present invention can be further exhibited.
[0066]
Further, like the invention according to claim 10, in the invention according to any one of claims 1 to 9,
It is preferable to record the correction image on the photosensitive material by recording the number of lines within the range of 50 or more and 1000 or less on the photosensitive material,
Like the invention according to claim 22, in the invention according to any one of claims 13 to 21,
It is preferable that the correction image is recorded on the photosensitive material by recording the number of lines within the range of 50 or more and 1000 or less on the photosensitive material.
[0067]
According to the above configuration, the density unevenness of the high frequency component can be reduced.
[0068]
Further, like the invention according to claim 11, in the invention according to claim 10,
It is preferable that the correction processing unit obtains the read information from 10% or more of the lines constituting the correction image,
Like the invention according to claim 23, in the invention according to claim 22,
It is preferable to acquire read information from 10% or more of the lines constituting the correction image.
[0069]
Further, like the invention according to claim 12, in the invention according to any one of claims 1 to 11,
Preferably, the light amount correction coefficient is adjusted by the correction amount, and an output value conversion LUT is adjusted by the exposure amount information.
Like the invention according to claim 24, in the invention according to any one of claims 13 to 23,
It is preferable that the light amount correction coefficient is adjusted according to the correction amount, and an output value conversion LUT is adjusted according to the exposure amount information.
[0070]
With the above configuration, the light amount correction coefficient of the print head and the exposure amount information become mutually independent information, and it is possible to stably obtain a high-quality output image for a long period of time.
[0071]
In addition, the image reading device according to the present invention includes a line CCD, and a device that reads an image by scanning the line CCD is a preferable example, and various scanners such as a flatbed scanner and a drum scanner are included. Can be
[0072]
When the density of a correction image is measured using the image reading device, the resolution (for example, 1200 dpi) is higher than the resolution (for example, 300 dip) recorded on the photosensitive material using the array print head. It is preferable to read the correction image.
[0073]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the image forming apparatus 100 according to the present embodiment will be described.
[0074]
1 and 2 show a schematic configuration of the image forming apparatus 100. FIG.
As shown in FIG. 1, the image forming apparatus 100 includes a support drum 1, a red print head 30a, a green print head 30b, a blue print head 30c, a print head control unit 40, a correction processing unit 60, an image reading device 70, and the like. It is composed.
[0075]
A color photographic paper (hereinafter referred to as photographic paper 2), which is a silver halide photographic light-sensitive material, unwound from a roll of the support drum 1, is conveyed in the direction indicated by an arrow by the support drum 1 rotated by a drive source (not shown). Then, the red print head 30a, the green print head 30b, and the blue print head 30c sequentially expose a predetermined position of the photographic paper 2 based on the exposure control according to the image information for output by the print head control unit 40. 2, a latent image of a color image is formed. When the exposure process is completed, the printing paper 2 is transported by the support drum 1 to the developing process.
[0076]
Each of the red print head 30a, the green print head 30b, and the blue print head 30c has a light source as a recording element arranged in an array of one or more rows. An LED light source is used for the red print head 30a, and a vacuum fluorescent print head that can be easily separated by a color filter with relatively high luminance and high speed response is used for the green print head 30b and the blue print head 30c. The photographic paper 2 is not limited to roll paper, but may be cut paper, and the method of transporting the photographic paper 2 is not particularly limited.
[0077]
The red print head 30a includes a shift register 31, a latch circuit 32, a driver circuit 33, a recording element array 34, a selfoc lens array 35, and the like, as shown in FIG. The same applies to the green print head 30b and the blue print head 30c, not limited to the red print head 30a.
[0078]
In the red print head 30a (the same applies to the green print head 30b and the blue print head 30c), first, MSB (most significant bit) data is transmitted from the print head control unit 40 to the shift register 31 as image bit data for one line. Then, the set pulse signal is input from the print head control unit 40 to the latch circuit 32, and the data of the MSB is latched by the latch circuit 32 for one line in synchronization with the set pulse signal. Here, the image bit data means data of a specific bit in the output image information.
[0079]
When an enable signal corresponding to the gradation is input from the print head control unit 40 to the driver circuit 33, the red print head 30a drives and controls the recording element in accordance with the enable signal, and is latched by the latch circuit 32. Light is emitted according to the data of the MSB. That is, the driver circuit 33 selectively transmits the driving signal to the recording element array 34 for the recording element whose latched data is “1”, and emits light for the time width of the enable signal. The irradiation light forms an image on the photographic printing paper 2 via the SELFOC lens array 35 to form a latent image. Such processing is sequentially performed for all bits from the MSB to the LSB (least significant bit), thereby completing the recording of one line. The order of the bits may start from the LSB, but may be another order and is not limited.
[0080]
When 8-bit image information is input for each of red, green, and blue, the print head control unit 40 converts the input image information into 12-bit output image information based on an output value conversion LUT including exposure amount information. Convert to In this case, the output image information is one line of serial digital data for each recording element, and includes a set pulse signal for transmitting image bit data to the latch circuit 32 and a set pulse signal for controlling the light emission time. An enable signal is generated, and the image bit data, the set pulse signal, and the enable signal are output to each of the red print head 30a, the green print head 30b, and the blue print head 30c.
[0081]
The print head control unit 40 controls the enable signal based on the light amount correction coefficient for correcting the emission characteristics of the red print head 30a, the green print head 30b, and the blue print head 30c input from the correction processing unit 60, and The light emission characteristics of the print head 30a, the green print head 30b, and the blue print head 30c are adjusted.
[0082]
In the VFPH having the emission characteristics of the green and blue components, green and blue color separation filters (not shown) are arranged below the SELFOC lens array 35, so that the print head control unit 40 transmits each color. Recording control is performed while sequentially shifting the exposure timing of the red print head 30a, the green print head 30b, and the blue print head 30c so that the image information is recorded at a predetermined position on the photographic paper 2. Thus, a color image can be properly recorded on the photographic paper 2.
[0083]
The correction processing unit 60 calculates a light amount correction coefficient for correcting the light emission characteristics of the red print head 30a, the green print head 30b, and the blue print head 30c from the density information, and outputs the light amount correction coefficient to the print head control unit 40.
[0084]
Next, the correction image 2a used in the present embodiment will be described. The correction image 2a is recorded on the photographic paper 2 by the image forming apparatus 100, and is used when calculating a light amount correction coefficient and a correction amount for an exposure amount.
[0085]
As shown in FIG. 3, the correction image 2a is individually recorded by each of the red print head 30a, the green print head 30b, and the blue print head 30c, and the YMC dyes of the respective basic colors are individually formed. As shown in FIG. 4 (a), the recording is simultaneously performed by the red print head 30a, the green print head 30b, and the blue print head 30, and the dyes of the respective basic colors are formed at the same place. Is also good.
[0086]
As shown in FIG. 4A, the correction image 2a includes a red print head 30a, a green print head 30a, a green print head 30b, and a green print head 30c. It is preferable to clarify the arrangement order of the recording elements of the head 30b and the blue print head 30c, and to have a marker stage capable of individually specifying the recording elements.
[0087]
From the above-mentioned purpose of use, the marker interval of the marker step is a fine interval, for example, the interval is preferably within 10 pixels, more preferably within 5 pixels, and most preferably 1 pixel. Here, one pixel interval means repetition of ON, OFF, ON, OFF,... For each pixel.
[0088]
Further, since there is a concern that the mounting accuracy of the red print head 30a, the green print head 30b, and the blue print head 30c may include some errors, the correction image 2a includes the red print head 30a, the green print head 30b, Preferably, each blue printhead 30c has a marker step. As shown in FIG. 4B, the correction image 2a is, for each of the basic colors, that is, the red print head 30a and the green print, when the pigments of the respective basic colors are developed at the same place. More preferably, a marker step is provided for each of the head 30b and the blue print head 30c.
[0089]
In FIG. 4A, only one marker stage is present, but it may be present at a plurality of locations. In particular, in the case of being configured to be recorded at a plurality of locations, it is preferable that a marker step is present near the location where the information is recorded, and it is preferable that the marker is present at a plurality of locations, and the marker is recorded. It is preferred to be present between locations.
[0090]
When the correction image 2a includes a plurality of marker steps, it is preferable that the plurality of marker steps be recorded (that is, printed) by the same recording element.
[0091]
When the correction image 2a is recorded on the cut (sheet-shaped) photographic paper 2 instead of the roll, the correction image 2a is preferably recorded at the center of the photographic paper 2 as much as possible. Preferably, an unrecorded area is formed on the photographic paper 2 in the leading direction.
[0092]
When each of the basic colors of YMC is individually recorded on the photographic paper 2 by each of the red print head 30a, the green print head 30b, and the blue print head 30c as the correction image 2a, a portion composed of the Y dye is formed. It is preferable from the viewpoint of developability that the film is conveyed to the development processing machine so that it is processed last.
[0093]
The correction image 2a is preferably such that a plurality of image data are separately recorded in a plurality of different areas on the photographic paper 2, and image data recorded at a low density to image data recorded at a high density It is preferable from the viewpoint of simplification of the calculation process that the recording is performed in order, and it is preferable from the viewpoint of developability that the portion recorded at a lower density is conveyed to the developing processor so as to be processed earlier.
[0094]
The range and the place where the density measurement is performed on the correction image 2a are as wide as possible, and it is preferable that there are many places. The number of lines to be recorded is preferably in the range of 50 or more and 1000 or less, more preferably 50 or more and 200 or less, and even more preferably 60 or more and 100 or less. Further, it is preferable to perform density measurement for obtaining a light amount correction coefficient and a correction amount for an exposure amount for 10% or more and 90% or less of the number of recorded lines, and more preferably 20% or more and 80% or less.
[0095]
The density range of the image for correction is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, most preferably 0.5 to 0.7 in R (Red). (Green), preferably from 0.2 to 1.5, more preferably from 0.3 to 0.8, most preferably from 0.4 to 0.6, and in B (Blue), from 0.15 to 1 .5 is preferred, 0.3 to 1.0 is more preferred, and the range of 0.4 to 0.6 is most preferred.
[0096]
Next, the operation will be described.
An image forming process performed by the image forming apparatus 100 will be described with reference to a flowchart illustrated in FIG.
[0097]
When 8-bit image information is input for each of red, green, and blue (step S1), the print head control unit 40 converts the input image information into 12-bit data based on an output value conversion LUT including exposure amount information. (Step S2).
Here, an example of the output value conversion LUT used in the present embodiment is shown in FIG. According to the output value conversion LUT, the correlation between the input value and the output value is non-linear.
[0098]
Further, the print head control unit 40 controls the enable signal based on the light amount correction coefficient for correcting the emission characteristics of the red print head 30a, the green print head 30b, and the blue print head 30c input from the correction processing unit 60. The light emission characteristics of the red print head 30a, the green print head 30b, and the blue print head 30c are adjusted (step S3).
[0099]
Thereafter, the print head controller 40 transmits the output image information for each color to each of the red print head 30a, the green print head 30b, and the blue print head 30c (step S4), and records the information on the photographic paper 2 (step S4). S5).
[0100]
Thereafter, the photographic paper 2 on which the output image is recorded is subjected to a developing process (step S6), and when the development is completed (step S7), the image forming process is terminated (step S7).
[0101]
Next, Experimental Examples 1 to 9 performed using the image forming apparatus 100 having the above configuration will be described. In Experiments 1 to 4, the correction image 2a shown in FIG. 3 is used, and in Experiments 5 to 9, the correction image 2a shown in FIGS. 4A and 4B is used.
[0102]
(Experimental example 1)
First, Experimental Example 1 will be described. In Experimental Example 1, in the following two cases, (1) the required time and (2) the visual evaluation of a human image including a gray gradation were compared.
[0103]
Case 1: One correction image 2a is output, and both density unevenness correction (that is, calculation of a light amount correction coefficient) and setup (that is, change of exposure amount information) are performed based on the correction image 2a. The correction image 2a in this case may be the one shown in FIG. 3 or FIG. 4, but in this embodiment, the one shown in FIG. 3 was used. In this case, the density unevenness correction and the setup are executed by the correction processing unit 60 according to the flowchart shown in FIG.
Case 2: A different correction image 2a is output and used for density unevenness correction and setup. Here, the density unevenness correction is executed by the correction processing unit 60 according to the flowchart shown in FIG. 7A, and the setup is executed by the correction processing unit 60 according to the flowchart shown in FIG. 7B.
[0104]
Here, the processes shown in the flowcharts of FIGS. 6, 7A and 7B will be described. The respective processes are executed by the correction processing unit 60 for each of the red print head 30a, the green print head 30b, and the blue print head 30c.
[0105]
First, the processing shown in the flowchart of FIG. 6 will be described.
The correction processing unit 60 outputs, for example, a correction image 2a as shown in FIG. 3 or FIG. 4 (Step S11).
[0106]
Thereafter, when the image for correction 2a output in the processing of step S11 is scanned by the image reading device 70 and the image information obtained by the scanning is input (step S12), the correction processing unit 60 performs the input. From the obtained image information, the position of each recording element on the correction image 2a is specified based on the image information related to the marker stage of the correction image 2a (step S13).
[0107]
Thereafter, the correction processing unit 60 acquires the density corresponding to each recording element (Step S14), and calculates the density average value D of each density (Step S15).
[0108]
After that, the correction processing unit 60 performs the calculation of the light amount correction coefficient and the change of the exposure amount in parallel (step S16).
[0109]
First, the calculation of the light quantity correction coefficient will be described.
The correction processing unit 60 compares the density average value D with the density corresponding to each printing element (step S17), and calculates a light quantity correction coefficient for each printing element (step S18).
[0110]
Next, updating of the exposure amount will be described.
The correction processing unit 60 calculates log (S) corresponding to the density average value D based on the straight line of the slope (γ) of the characteristic curve of the photosensitive material as shown in FIG. 8 (step S19), and furthermore, From the logarithm (S0) corresponding to the prepared target density D0, a change amount ΔE of the exposure amount is calculated according to the following equation: ΔE = log (S) −log (S0) (step S20).
[0111]
Here, the horizontal axis “log (output value)” of the graph shown in FIG. 8 is a logarithm of the output value of the output image information converted by the output value conversion LUT, and the vertical axis is “density”. Is density information of the output image. In this case, an output conversion LUT in which the correlation between the input value and the output value is non-linear is used.
[0112]
Further, the slope (γ) of the characteristic curve of the photosensitive material as shown in FIG. 8 is known in advance depending on the type of the photosensitive material.
[0113]
Thereafter, the correction processing unit 60 updates the exposure amount information by adding the correction of ΔE to the currently set exposure amount E (that is, E + ΔE → E) (step S21).
[0114]
The correction processing unit 60 confirms that the calculation of the light amount correction coefficient and the update of the exposure amount have been completed (step S22), and ends the processing.
[0115]
Next, the processing shown in the flowchart of FIG. This process only calculates the light amount correction coefficient.
[0116]
The correction processing unit 60 outputs, for example, a correction image 2a as shown in FIG. 3 or FIG. 4 (Step S31).
[0117]
Thereafter, when the image for correction 2a output in the process of step S31 is scanned by the image reading device 70 and image information obtained by the scanning is input (step S32), the correction processing unit 60 determines that the input is correct. From the obtained image information, the position of each recording element on the correction image 2a is specified based on the image information on the marker stage of the correction image 2a (step S33).
[0118]
Thereafter, the correction processing unit 60 acquires the density corresponding to each recording element (Step S34), and calculates the density average value D of each density (Step S35).
[0119]
Thereafter, the correction processing unit 60 compares the density average value D with the density corresponding to each recording element (step S36), and calculates a light quantity correction coefficient for each recording element (step S37). Thus, the process shown in this flowchart is completed.
[0120]
Next, the processing shown in the flowchart of FIG. 7B will be described. This processing only updates the exposure amount.
[0121]
The correction processing unit 60 outputs, for example, a gray solid image for bitmap recorded with the output value S0 of the output image information corresponding to each print head (step S41).
[0122]
Thereafter, the correction processing unit 60 scans the gray solid image output in the process of step S31 by the image reading device 70, and inputs image information obtained by the scanning. From the information, the position of each recording element on the correction image 2a is specified based on the image information on the marker step of the correction image 2a.
[0123]
Thereafter, the correction processing unit 60 acquires the density corresponding to each recording element and calculates the average density value D of each density (step S42).
[0124]
The correction processing unit 60 calculates log (S) corresponding to the density average value D based on the straight line of the slope (γ) of the characteristic curve of the photosensitive material as shown in FIG. 13 (step S43), and furthermore, From the log (S0) corresponding to the prepared target density D0, a change amount ΔE of the exposure amount is calculated according to the following formula: ΔE = log (S) −log (S0) (step S44).
[0125]
Thereafter, the correction processing unit 60 adds the correction of ΔE to the currently set exposure amount E to update the exposure amount information (that is, E + ΔE → E.) (Step S45). Thus, the process shown in this flowchart is completed.
[0126]
According to the experimental results of Experimental Example 1, the required time in Case 1 was reduced by approximately 75% compared to Case 2. The output image in case 1 was extremely good.
[0127]
Further, if the exposure amount information is obtained by using the statistic, the required time is further reduced by approximately 70% from the result of the above-described case 1.
[0128]
(Experimental example 2)
Next, Experimental Example 2 will be described. In Experimental Example 2, the following two cases were performed.
[0129]
Case 1: The processing of Case 1 of Experimental Example 1 is sequentially repeated, and the finally obtained light amount correction coefficient is evaluated. In this case, the light amount correction coefficient and the exposure amount are calculated as independent correction amounts.
Case 2: The processing according to the flowchart shown in FIG. 9 is repeatedly performed, and the finally obtained light quantity correction coefficient is evaluated. In this case, only the light amount correction coefficient is calculated without changing the exposure amount information. In this case, the obtained light amount correction coefficient depends on the exposure amount.
[0130]
Here, the light amount correction coefficient used was a numerical value in the range of 0 to 4095. The image used in Experimental Example 2 was corrected by appropriately adjusting the exposure amount information and using the correction image 2a shown in FIG. 3 having a relatively low density.
[0131]
Here, the processing shown in the flowchart of FIG. 9 will be described. This processing is executed by the correction processing unit 60 for each of the red print head 30a, the green print head 30b, and the blue print head 30c.
[0132]
First, the correction processing unit 60 outputs, for example, a correction image 2a as shown in FIG. 3 or FIG. 4 (step S51).
[0133]
Thereafter, when the image for correction 2a output in the processing of step S51 is scanned by the image reading device 70 and image information obtained by the scanning is input (step S52), the correction processing unit 60 performs the input. Based on the obtained image information, the position of each recording element (hereinafter, for example, the i-th recording element is referred to as recording element (i)) on the correction image 2a based on the image information related to the marker stage of the correction image 2a. Is specified (step S53).
[0134]
Thereafter, the correction processing unit 60 acquires the density corresponding to each recording element (i) (Step S54), and calculates the density average value D of each density (Step S55).
[0135]
Thereafter, the correction processing unit 60 performs the calculation of the light amount correction coefficient C (i) corresponding to each recording element (i) and the processing related to the exposure amount in parallel (step S56).
[0136]
First, the processing related to the exposure amount will be described.
The correction processing section 60 calculates log (S) corresponding to the density average value D based on a straight line of the gradient (γ) of the characteristic curve of the photosensitive material as shown in FIG. 13 (step S57), and furthermore, From the log (S0) corresponding to the prepared target density D0, an amount S0 / S relating to the exposure amount is calculated (step S58).
[0137]
Next, the calculation of the light quantity correction coefficient C (i) will be described.
The correction processing unit 60 compares the density average value D with the density corresponding to each printing element (step S59), and calculates the correction amount of the printing characteristic for each printing element (i) (step S60).
[0138]
The correction processor 60 corrects the light amount correction coefficient C (i) corresponding to each of the currently set recording elements (i) with respect to the recording characteristic correction amount for each of the recording elements (i) and the recording element (i). ) Is multiplied by S0 / S, which is a common amount, to calculate a new light amount correction coefficient C (i) (step S61). Thus, the processing shown in the present flowchart ends.
[0139]
According to the experimental results of Experimental Example 2, the average value of the finally obtained light amount correction coefficient in case 1 is approximately 2050, and the average value of the finally obtained light amount correction coefficient in case 2 Was approximately 4000. Therefore, when the light amount correction coefficient becomes extremely large or small, pixel unevenness correction becomes insufficient in Case 2, and it is preferable that the light amount correction coefficient and the exposure amount information have independent functions.
[0140]
(Experimental example 3)
Next, Experimental Example 3 will be described. In Experimental Example 3, the density of the correction image 2a output in the process of step S11 in the flowchart of FIG. 6 is (1) light (a non-linear portion indicated by a symbol B in FIG. 17) and (2) intermediate. (Linear portion indicated by reference symbol A in FIG. 17) and (3) Dark (non-linear portion indicated by reference symbol C in FIG. 17) were performed in the same manner as in Case 1 of Experimental Example 1. .
[0141]
According to the experimental results of Experimental Example 3, the accuracy of the density unevenness correction and the setup was slightly lowered in cases other than (2).
[0142]
(Experimental example 4)
Next, Experimental Example 4 will be described. In Experimental Example 4, density unevenness correction and setup are both performed on the correction image 2a based on images recorded in two areas. In this case, the density unevenness correction and the setup are executed by the correction processing unit 60 according to the flowchart shown in FIG.
[0143]
Here, the processing shown in the flowchart of FIG. 10 will be described. This processing is executed by the correction processing unit 60 for each of the red print head 30a, the green print head 30b, and the blue print head 30c.
[0144]
First, the correction processing unit 60 outputs, for example, the correction image 2a shown in FIG. 4A (step S71).
[0145]
Thereafter, when the image for correction 2a output in the processing of step S71 is scanned by the image reading device 70 and image information obtained by the scanning is input (step S72), the correction processing unit 60 determines that the input is correct. From the obtained image information, the position of each recording element on the correction image 2a is specified based on the image information related to the marker stage of the correction image 2a (step S73). The correction image 2a in this case has two density steps as shown in FIG.
[0146]
Thereafter, the correction processing unit 60 acquires the density corresponding to each density step and each printing element, calculates the density average value of each density step for each printing element, and sets it as the density of each printing element (step S74). A density average value D obtained by further averaging the calculated density average values for each density step is calculated (step S75).
[0147]
Thereafter, the correction processing unit 60 performs the calculation of the light amount correction coefficient and the change of the exposure amount in parallel (step S76).
[0148]
First, the calculation of the light quantity correction coefficient will be described.
The correction processing unit 60 compares the density average value D with the density corresponding to each recording element (step S77), and calculates a light quantity correction coefficient for each recording element (step S78).
[0149]
Next, updating of the exposure amount will be described.
The correction processing unit 60 calculates log (S) corresponding to the density average value D based on a straight line of the slope (γ) of the characteristic curve of the photosensitive material as shown in FIG. 13 (step S79), and furthermore, From the log (S0) corresponding to the prepared target density D0, the change amount ΔE of the exposure amount is calculated according to the following formula: ΔE = log (S) −log (S0) (step S80).
[0150]
Thereafter, the correction processing unit 60 updates the exposure amount information by adding the above-described correction of ΔE to the currently set exposure amount E (that is, E + ΔE → E) (step S81).
[0151]
The correction processing unit 60 confirms that the calculation of the light amount correction coefficient and the update of the exposure amount have been completed (step S82), and ends the processing.
[0152]
According to the experimental result of Experimental Example 4, the accuracy of the density unevenness correction and the setup was improved.
[0153]
(Experimental example 5)
Next, Experimental Example 5 will be described. In Experimental Example 5, based on the images recorded in a plurality of areas of the correction image 4a, if the respective densities are (1) substantially the same, (2) different, (3) a different method not according to the present invention is used. In each of the three cases, the density unevenness correction and the setup are performed from the same inferior density unevenness and color balance for each of the three cases. Compared by number.
In this case, the density unevenness correction and the setup are executed by the correction processing unit 60 according to the flowchart of FIG.
[0154]
Here, the processing shown in the flowchart of FIG. 11 will be described. This processing is executed by the correction processing unit 60 for each of the red print head 30a, the green print head 30b, and the blue print head 30c.
[0155]
First, when 8-bit image information is input for each of red, green, and blue, the print head controller 40 outputs the input image information to a 12-bit output based on an output value conversion LUT including exposure amount information. (See steps S1 and S2 in FIG. 5). Here, in the output value conversion LUT, as shown in FIG. 13, the correlation between the input value and the output value is non-linear.
[0156]
Next, the correction processing unit 60 outputs the correction image 2a in which the four density steps shown in FIG. 12 are recorded, based on the above-described 12-bit output image information (step S91). The densities in the four density stages are different from each other.
[0157]
After that, when the image for correction 2a output in the process of step S91 is scanned by the image reading device 70 and the image information obtained by the scanning is input (step S92), the correction processing unit 60 performs the input. From the obtained image information, the position of each recording element (i) on the correction image 2a is specified based on the image information related to the marker stage of the correction image 2a (steps S93, S94).
[0158]
Thereafter, the correction processing unit 60 obtains the density corresponding to each recording element (i) (step S95), and averages the values (ave-1 to ave-1) of the density in each density step (see FIG. 12) of the correction image 2a. ave-4) and the average value (ave-all) of all the concentrations are calculated (step S96).
[0159]
Here, for example, ave-1 is obtained by averaging the densities corresponding to the respective recording elements (i) in the first stage of the density stage of the correction image 2a (see FIG. 12). The same applies to ave-2 to ave-4.
[0160]
After that, the correction processing unit 60 performs the calculation of the light amount correction coefficient and the change of the exposure amount in parallel (step S97).
[0161]
First, the calculation of the light quantity correction coefficient will be described.
The correction processing unit 60 calculates an average value ave-pix (i) of the density in the four density steps for each recording element (i), and calculates each recording element based on ave-all and ave-pix (i). The light amount correction coefficient of the element (i) is calculated (steps S98 and S99).
[0162]
Next, updating of the exposure amount will be described.
As illustrated in FIG. 14, the correction processing unit 60 specifies two density average values of the values closest to D0 while sandwiching the target density D0 from ave-1 to ave-4. For example, in the example illustrated in FIG. 14, the correction processing unit 60 specifies ave-2 and ave-3 as two density average values that sandwich D0 and are closest to D0.
Here, the horizontal axis “log (output value)” of the graph shown in FIG. 14 is obtained by taking the log of the output value of the image information for output converted by the output value conversion LUT shown in FIG. The axis “density” is density information of the output image.
[0163]
The correction processing unit 60 estimates log (S) at which the target density D0 is realized by interpolating the ave-2 and ave-3 from the regression line (step S100). Here, S-1 to S-4 and S shown in FIG. 14 are output values of image information such that the respective densities of ave-1 to ave-4 and D0 are realized with respect to the regression line.
[0164]
After step S100, the correction processing unit 60 calculates the change amount ΔE of the exposure amount based on the logarithm log (S0) of the output value S0 of the image information which is currently set in advance and the log (S), using a formula: It is calculated according to ΔE = log (S) −log (S0) (step S101).
[0165]
Thereafter, the correction processing unit 60 updates the exposure amount information by adding the above-described correction of ΔE to the currently set exposure amount E (that is, E + ΔE → E) (step S102).
[0166]
The correction processing unit 60 confirms that the calculation of the light amount correction coefficient and the update of the exposure amount are completed (step S103), and ends the processing.
[0167]
In the above description of the flowchart of FIG. 11, the LUT is non-linear as shown in FIG. In this case, as shown in FIG. 14, the characteristics of "log (S) -density information" are also assumed to be non-linear. However, the present invention is not limited to this, and a special example is a case where the LUT is linear as shown in FIG. 15 and the characteristic of “log (S) -density information” is a straight line. May be.
[0168]
In such a case, in step S100, the correction processing unit 60 estimates log (S) at which the target density D0 is realized from the regression line by interpolating ave-1 to ave-4 as shown in FIG. (Step S100). The processes after step S101 are the same as those described above.
[0169]
Although the number of concentration steps is four, the number is not limited to this and may be any number.
[0170]
According to the experimental results of Experimental Example 5, the case of (1) was 4 sheets, the case of (2) was 2 sheets, and the case of (3) was 12 sheets. That is, if two images having different densities are used, the time required for density unevenness correction and setup is reduced.
[0171]
(Experimental example 6)
Next, Experimental Example 6 will be described. In Experimental Example 6, the photographic paper 2 on which the correction image 2a was recorded was pressed by a reading unit (not shown) of the image reading device 70 by a black pressing member such as rubber. Thereby, the correction of the edge portion becomes good, and the floating and the bending of the paper are reduced. Therefore, unevenness of the low frequency component is reduced.
[0172]
(Experimental example 7)
Next, Experimental Example 7 will be described. In Experimental Example 7, density unevenness was evaluated based on the following evaluation criteria. FIG. 18 shows the result. As shown in FIG. 18, by setting the width of the photographic paper 2 on which the correction image 2a is recorded to be 10 to 1000, it is possible to reduce the density unevenness. In particular, by increasing the width of the photographic paper 2 by 10% or more, the correction image 2a can be reduced in size, which is preferable from the viewpoint of shortening the calculation time and reducing loss paper.
[0173]
Hereinafter, the evaluation criteria of the density unevenness evaluation shown in FIG. 18 will be described. “◎” indicates that there is no density unevenness and the image quality is extremely good, and “○” indicates that although the density unevenness is partially confirmed slightly, the image quality is very good. “Δ” indicates that the image quality was good, although the density unevenness was slightly confirmed, and “×” indicates that the image quality was unfavorable, and the density unevenness was confirmed.
[0174]
(Experimental example 8)
Next, Experimental Example 8 will be described. In Experimental Example 8, the photosensitive material of the photographic paper 2 on which the correction image 2a was recorded was used as a silver halide photosensitive material. Thereby, the effect of the present invention was further exhibited.
[0175]
(Experimental example 9)
Next, Experimental Example 9 will be described. In Experimental Example 9, the photosensitive material of the photographic paper 2 on which the correction image 2a was recorded was one having a reflective support. Thereby, the effect of the present invention was further exhibited.
[0176]
As described above, according to the image forming apparatus 100 of the present embodiment, two steps of density unevenness correction and setup can be performed in parallel.
[0177]
Therefore, it is possible to easily realize an image forming apparatus and an image forming method in which preliminary preparations for full-scale operation such as density unevenness correction and setup can be accurately performed in a short time.
[0178]
The description in the above embodiment shows a specific example of the image forming apparatus and the image forming method according to the present invention, and the present invention is not limited to this. The detailed configuration and detailed operation of the image forming apparatus 100 according to the present embodiment can be appropriately changed without departing from the spirit of the present invention.
[0179]
【The invention's effect】
According to the present invention, since the correction based on the exposure information and the correction based on the light amount correction coefficient can be performed in parallel, the image forming apparatus and the image forming apparatus can perform the preparation for the full operation such as the correction processing in a short time and accurately. A forming method can be realized.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of an image forming apparatus to which the present invention has been applied.
FIG. 2 is a block diagram illustrating the configuration of an image forming apparatus to which the present invention is applied in more detail.
FIG. 3 is an example of a correction image used by the image forming apparatus to which the present invention is applied.
FIG. 4A is an example of a correction image used by the image forming apparatus to which the present invention is applied, and FIG. 4B is an enlarged view of the marker stage shown in FIG.
FIG. 5 is a flowchart illustrating an image forming process performed by the image forming apparatus to which the present invention has been applied.
FIG. 6 is a flowchart illustrating processing performed in an experimental example for an image forming apparatus to which the present invention has been applied.
FIGS. 7A and 7B are flowcharts illustrating processing executed in an experimental example for an image forming apparatus to which the present invention is applied.
FIG. 8 is a diagram illustrating a correlation between an output value of image information and a density used in an experimental example of an image forming apparatus to which the present invention is applied.
FIG. 9 is a flowchart illustrating processing performed in an experimental example for an image forming apparatus to which the present invention has been applied.
FIG. 10 is a flowchart illustrating processing performed in an experimental example for an image forming apparatus to which the present invention has been applied.
FIG. 11 is a flowchart illustrating processing performed in an experimental example for an image forming apparatus to which the present invention has been applied.
FIG. 12 is an example of a correction image used when processing the flowchart shown in FIG. 11;
FIG. 13 is an example of an LUT used in an experimental example for an image forming apparatus to which the present invention is applied.
FIG. 14 is a diagram illustrating a correlation between an output value of image information and a density, which is used in an experimental example for an image forming apparatus to which the present invention is applied.
FIG. 15 is a diagram illustrating a correlation between an output value of image information and a density, which is used in an experimental example for an image forming apparatus to which the present invention is applied.
FIG. 16 is a diagram schematically showing a print head in which recording elements are arranged in an array.
FIG. 17 is a diagram illustrating an example of a characteristic curve of a photosensitive material.
FIG. 18 is a diagram illustrating density unevenness evaluation performed by the image forming apparatus to which the present invention is applied.
[Explanation of symbols]
1 Support drum
2 photographic paper
2a Correction image
30a red print head
30b green printhead
30c blue print head
31 shift register
32 Latch circuit
33 Driver Circuit
34 Recording element array
35 Selfoc lens array
40 Printhead control unit
60 Correction processing unit
70 Image reading device
100 Image forming apparatus

Claims (24)

A print head in which a plurality of recording elements each operating based on an individual light amount correction coefficient are arranged in an array,
An image reading device that reads an image recorded on a photosensitive material,
The correction image is recorded on the photosensitive material using the print head, the read information of the recorded correction image is obtained via the image reading device, and the recording of each of the recording elements is performed based on the obtained read information. A correction processing unit that obtains a correction amount for the characteristic, and corrects the light amount correction coefficient using the obtained correction amount;
With
In an image forming apparatus that records an image using each of the recording elements based on the light amount correction coefficient corrected by the correction processing unit,
An image forming apparatus for acquiring exposure amount information based on read information acquired from the correction image. The image forming apparatus according to claim 1, wherein a statistic related to the read information is calculated, and the exposure amount information is acquired using the calculated statistic. The image forming apparatus according to claim 1, wherein recording is performed on a photosensitive material using the light amount correction coefficient and the exposure amount information independently of each other. The image forming apparatus according to claim 1, wherein a value indicated by the read information acquired from the correction image is set in a linear portion of a characteristic curve of the photosensitive material. The correction image is recorded in a plurality of different recording areas on the photosensitive material surface, read information is obtained from each of the correction images recorded in the plurality of recording areas, and the exposure is performed based on the obtained read information. The image forming apparatus according to any one of claims 1 to 4, wherein the amount information is acquired. The image forming apparatus according to claim 5, wherein correction images are recorded at different densities in each of the plurality of recording areas. The image forming apparatus according to any one of claims 1 to 6, wherein the image reading device includes a pressing member for fixing the correction image to the image reading device. The image forming apparatus according to any one of claims 1 to 7, wherein the correction image is recorded on a photosensitive material made of silver halide. The image forming apparatus according to claim 1, wherein the correction image is recorded on a photosensitive material having a reflective support. 10. The image for correction is recorded on the photosensitive material by recording, on the photosensitive material, lines having a number of lines within a range of 50 or more and 1000 or less. An image forming apparatus according to claim 1. The image forming apparatus according to claim 10, wherein the correction processing unit acquires the read information from 10% or more of the lines configuring the correction image. The image forming apparatus according to claim 1, wherein the light amount correction coefficient is adjusted by the correction amount, and an output value conversion LUT is adjusted by the exposure amount information. A correction image recording step of recording a correction image on a photosensitive material using a print head in which a plurality of recording elements each operating based on an individual light amount correction coefficient are arranged in an array, and A read information acquisition step of acquiring read information via an image reading device; a correction amount acquisition step of acquiring a correction amount for a recording characteristic of each of the recording elements based on the acquired read information; and A correction step of correcting the light quantity correction coefficient using an image recording step of recording an image using each of the recording elements based on the corrected light quantity correction coefficient.
An image forming method, further comprising an exposure amount information acquiring step of acquiring exposure amount information based on read information acquired from the correction image. 14. The image forming method according to claim 13, wherein a statistic related to the read information is calculated, and the exposure amount information is obtained using the calculated statistic. 15. The image forming method according to claim 13, wherein recording is performed on a photosensitive material using the light amount correction coefficient and the exposure amount information independently of each other. The image forming method according to claim 13, wherein a value indicated by the read information acquired from the correction image is set in a linear portion of a characteristic curve of the photosensitive material. The correction image is recorded in a plurality of different recording areas on the photosensitive material surface, read information is obtained from each of the correction images recorded in the plurality of recording areas, and the exposure is performed based on the obtained read information. The image forming method according to claim 13, wherein the amount information is acquired. 18. The image forming method according to claim 17, wherein a correction image is recorded in each of the plurality of recording areas by different reading. 19. The image forming method according to claim 13, wherein the correction image is held by using a pressing member in the image reading device. The image forming method according to any one of claims 13 to 19, wherein the correction image is recorded on a photosensitive material made of silver halide. 21. The image forming method according to claim 13, wherein the correction image is recorded on a photosensitive material having a reflective support. 22. The image according to claim 13, wherein the correction image is recorded on the photosensitive material by recording the number of lines within the range of 50 or more and 1000 or less on the photosensitive material. 2. The image forming method according to 1., 23. The image forming method according to claim 22, wherein the read information is obtained from 10% or more of the lines constituting the correction image. 24. The image forming method according to claim 13, wherein the light amount correction coefficient is adjusted according to the correction amount, and an output value conversion LUT is adjusted according to the exposure amount information.

Images