JP2530703B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more specifically, it discriminates a color original from at least a photographic original and a print original.
The present invention relates to an image forming apparatus that forms an image according to the color original document.

<Prior Art> In recent years, various copying apparatuses capable of copying color originals and image forming apparatuses such as color image printers have become widespread.

In order to obtain a good color image in this color image forming apparatus, it is necessary to finish the color balance and the density balance well.

In such an image forming apparatus, especially in a color copying apparatus, a photograph or a printed matter is often used as a color original. However, the coloring material and the visual sensitivity and the spectral sensitivity of the copying material are different between the photograph and the printed matter, and the same. When copying was performed under the copying conditions, the copied image had a different color balance.

For example, in a color printed document, the spectral density distributions of magenta ink and cyan ink have a large overlap. for that reason,
The color printing original has a high magenta density, and the color copying apparatus adjusted so that the color printing original is finished well has a copying condition in which the formation of the magenta density is suppressed.

Therefore, when a color photographic original is copied under this image forming condition, a magenta color is insufficient and a green copy image is formed, which is greenish.

Further, since the gradations of original images are different between color printed originals and color photographic originals, in a copying machine using various photosensitive materials such as silver halide photographic photosensitive materials, for example, the optimum photosensitive material for copying color printed originals. When a color photographic original is copied using a material (a photosensitive material having a high contrast), a halftone is not reproduced well, and a hard image is obtained.

Therefore, in order to obtain a good image according to the type of color original in one image forming apparatus, the type of original is determined and the image forming condition (color filter adjustment amount, exposure amount, etc.) is determined according to the original type. It is necessary to select a photosensitive material.

However, not only is it troublesome for the operator to visually check the original type each time a copy is made, but for an operator who does not have specialized knowledge, due to the recent advances in printing technology, it is possible to distinguish between printed matter and photographs. Sometimes it was difficult to distinguish and lacked accuracy.

Therefore, the applicant of the present invention has proposed an image forming apparatus for automatically determining the document type in Japanese Patent Application No. 63-243603. This image forming apparatus has two sensors having sensitivity peaks at different wavelengths for one primary color light for each of the three primary colors, and at least a color printing original document is obtained by using a predetermined discriminant function from the measured values by the six types of sensors. A color photograph original is discriminated and an image is formed according to the original type. This apparatus is capable of sufficiently reading the information of a color original and automatically and accurately determining the original type.

<Problems to be Solved by the Invention> By the way, in the image forming apparatus proposed in Japanese Patent Application No. 63-243603, the size of the photosensitive material is the same as that of the photosensitive material for image formation at the time of prescanning or reading information of a color original. Scanning photometric area of length. A calculation is performed using all the data read in this way to determine the color document type.

For this reason, the size of the original to be copied, such as the copying of a small size color original, especially the enlargement copy of the E size color print or the copy of the non-standard size color original, is
If the size of the original placement surface (platen surface) of the copying machine is smaller than the photometric area that is equal to the size of the photosensitive material, or if it is not placed properly, the position outside the original is measured during the photometric scanning of the original surface. In some cases, the original irradiation light transmitted through the original holding surface is reflected by the white surface of the original pressing plate and directly enters the sensor.Since the white part of the original pressing plate was also read as the original image and calculated, In some cases, the accurate document type could not be determined, and the color photographic document was identified as a color print document or an intermediate type document.

Also, when copying a color original smaller than the size of the photosensitive material on which an image is formed, or a three-dimensional object such as a package or a product, with the original holding plate open, or when a thick original book is opened. And lay it down on the document surface,
In addition, when copying in this state, the following major drawbacks occur.

This is for documents whose image forming device is smaller than the photometric area,
In the case of such a thick original that has a large dent in the outer circumference or center folding portion in the area that should originally belong to the original area, the original irradiation light actually exists when copying. A region where almost no reflected light is generated in the part of the original region that was originally supposed to have some reflected light, while directly transmitting the photometric region and the region of the original placement surface corresponding to this recessed portion This will occur. That is, when this phenomenon occurs, the sensor reads these areas as a very large density area, and the discrimination calculation is performed based on this data, so that the exact document type may not be discriminated.

An object of the present invention is to solve the above-mentioned problems of the prior art and to perform a prescan of a length corresponding to the size of a photosensitive material, even when a color original smaller than the photometric range at the time of prescan is copied. In particular, when enlarging and copying a small size color original, for example, an E size print, copying an atypical size color original, and copying with the original holding plate open such as a thick book, package, or three-dimensional object, An object of the present invention is to provide an image forming apparatus capable of accurately discriminating at least a color photographic original from a color printed original and performing proper image formation according to the type of the original.

<Means for Solving the Problems> In order to achieve the above object, the present invention measures reflected light in a predetermined photometric area including a color original document, and at least the original type of a photographic original and a print original based on the obtained photometric value. In the image forming apparatus for forming an image according to the color original, the original type determination operation is performed by removing the photometric values below the predetermined low level and / or above the predetermined high level from the photometric values. An image forming apparatus is provided which is characterized in that it is performed.

<Operation> The operation of the present invention having the above-described configuration is performed under various conditions for forming an image according to a color original, for example, color filter conditions,
When determining the exposure conditions such as aperture conditions and the type of original required when deciding the selection of the photosensitive material, the photometry below the predetermined low level and / or above the predetermined high level from the photometric value in the photometric area including the color original. By performing the discrimination operation excluding the values, it is possible to accurately copy even small-sized color originals, non-standard-sized color originals, color originals such as thick books or three-dimensional objects that are copied with the original holding plate open. Being able to do classification.

<Embodiment> Hereinafter, an image forming apparatus of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

First, a method of discriminating a document type in the image forming apparatus of the present invention will be described.

In the image forming apparatus of the present invention, the reflected light in the predetermined photometric area of the document placement surface including the color document is, for example, red (hereinafter R), green (hereinafter G), and blue (hereinafter B). For each of the three primary color lights, two types of sensors having sensitivity peaks at different wavelengths within the respective wavelength regions are used for measurement, and the color original is at least determined by the discriminant function values using the six types of measured values as parameters. It distinguishes between color photo originals and color print originals, and when performing the discrimination calculation, the discrimination accuracy is further improved by removing a predetermined low level and / or high level from the photometric value measured by the sensor. It was done like this.

Here, the photometric area referred to in the present invention is the range of the document placement surface that the sensor receives when reading or prescanning the image information of the color document placed on the document placement surface.

For example, it may be an area set as the original placement surface or an area that matches the original having the largest area of the color originals to be copied, or an area that is suitable for the scanning length during photometry.

However, the photometric area in the present invention is preferably determined according to the photosensitive material on which an image is formed.

Further, in the case of discriminating the document type by the prescan, one prescan area may be set in advance and the area may be set as a photometric area, or the size of the selected photosensitive material, usually a standard size, for example, B5 , B4, A4, A3, or a region slightly larger than these regions may be used as the photometric region.

By the way, in the image forming apparatus in which a predetermined area of the document placing surface is used as the photometric area as described above, a color original having a size smaller than the photometric area or an atypical size is set on the document placing surface, and the pressing surface is set. When the document holding plate whose white is white is pressed and it is photometrically scanned with the slit-shaped irradiation light, a part of the irradiation light is emitted from the original mounting surface in the area where the original does not exist. And is reflected by the white pressing surface of the document pressing plate to enter the photometric means.

Therefore, in copying in a state where there are many areas where there are no originals, the frequency of appearance relating to the photometric density of each small portion in the areas where there are no originals appears in the range of the lowest density level.

If this is expressed as a histogram for each photometric density in each small portion of the document, for example, the form shown in FIG.

On the other hand, when copying a color document of a size smaller than the photometric area or an irregular size with the document holding plate open, or when a thick book, which is the document, is opened, the document is turned down on the document placement surface, and When copying with, since there is no document in the photometric area or there is a large recess in the area that should belong to the document area, the area where no document exists or the area of the document placement surface corresponding to this recessed portion This causes a phenomenon in which the irradiation light is transmitted as it is, and the reflected light from it does not enter the photometric means at all or almost. Therefore, the photometric density of the area where the original does not exist or the concave portion is very high.

Therefore, in such a document in which there are many regions where there are no documents or many dents, the appearance frequency relating to the photometric density of each small part of the region corresponding to the non-document region and the dents is within the range of the highest density level. Will appear in many.

When this is expressed as a histogram for each photometric density in each small portion of the document, for example, the form shown in FIG. 2 is obtained.

Further, in the case of a package, a three-dimensional object, etc., the same problem arises because the document holding plate is not used or is used in a state in which it is larger than the document mounting surface.

Therefore, in the present invention, in order to accurately determine the document type of the color document, as described above, six sensors are used to measure six photometric values of two wavelengths of each color, that is, photometric data.

These photometric data are used to determine and calculate the image density, contrast, image area, image area density, background area, background density, black background area and black background density, etc., in addition to the document type. For photometry, color originals
In a predetermined direction, for example, scanning exposure, the measurement is performed at a predetermined number of measurement points (or lines or images) by dividing the scanning direction into predetermined intervals. For example, in the case of performing slit scanning exposure, it is preferable to perform photometry at intervals at least smaller than the width of the slit in the scanning direction. The number of photometric points thus obtained is n
Then, since the data measured by the R, G, and B sensors measure two wavelengths for each color, r1 ₁ , ... r1 _n ,
r2 ₁ , …… r2 _n , g1 ₁ , …… g1 _n , g2 ₁ …… g2 _n , b1 ₁ , …… b
For each wavelength of 1 _n , b2 ₁ ... b2 _n , 6 n pieces of n pieces are obtained.

In the present invention, a certain measurement point i (i-th measurement point)
Concentrations r1 _i , r2 _i , g1 _i , g2 _i , b1 _i , b2 _i within a predetermined concentration range, and the concentration at each measurement point and the measurement point j (jth measurement point) adjacent to this measurement point i r1 _j , r2 _j , g1
Concentration difference with _j , g2 _j , b1 _j , b2 _j △ r1 _i = | r1 _j −r1 _i | △ r2 _i = | r2 _j −r2 _i | △ g1 _i = | g1 _j −g1 _i | △ g2 _i = | g2 _j −g2 _i | △ b1 _i = | b1 _j −b1 _i | △ b2 _i = | b2 _j −b2 _i | is within the specified range, and there is a specified concentration change, this measurement point i is If it is in the area, the average density of the entire image area is used as the image area density (DM) for density correction. That is, for example, Δr1 _i , Δr2 _i , Δg1 _i , Δg2 _i ,
From the color density distribution for the measurement points where Δb1 _i and Δb2 _i are within the predetermined range, the density distribution of the three-color average of each point is shown in FIGS.
Create a histogram as shown in the figure and set the specified density range D _min
Except for high density portion of the to D _min + low density part and the predetermined concentration range of α D _max ~D _max -β, has an image area density by calculating the average density. Therefore, there is no concentration change, or very small portion and, D as shown in FIG. 1 or FIG. 2 _min to D _min
The low density area of + α and the high density area of D _{max to} D _max −β are not regarded as image areas.

By the way, in the discrimination and calculation of the image area and the density of the image area, it is not necessary to use all the photometric values of the above-mentioned six sensors. For example, for each color of R, G and B, a certain combination of one wavelength, r1 _i , g1 _i , b2
The photometric data of _i (i = 1 to n) may be used.

Except for special cases, red is r1 _i , green is g1 _i , and blue is b2.
_i (i = 1 to n) will be described as a typical example.

In the present invention, if at least one of r1 _i , g1 _i , and b2 _i is less than the predetermined density D _min + α, the measurement point i is a background area (back background, background), and the average of the entire background area is determined. The density is the background density (DB). In the present invention, if the background density is less than a predetermined low level, the background area is not included in the original type determination calculation.

Further, in the present invention, if at least one of r1 _i , g1 _i , and b2 _i exceeds a predetermined density D _max −β, the measurement point i is a black background area, and the average density of the entire black background area is The black background density (DBB). In the present invention, if the black background density is higher than a predetermined high level, the black background area is not included in the original type determination calculation.

By the way, from the histograms shown in FIGS. 1 and 2, the density level D _min + α that separates the image area and the background area from each other.
And the density level D _max that separates the image area from the black background area
−β may be determined as follows.

First, the minimum density value D _min and the maximum density value D _max in the photometric area are determined. As the minimum density value D _min , in addition to the actual photometric value, for example, a white density value used on the pressing surface of the document pressing plate of the copying apparatus may be used. In addition to the actual photometric value, for example, the maximum density value D _max may be set to a predetermined value as a density value for black, or
The photometric density value or the like when the document and the document holding plate do not coexist on the document placement surface may be used.

Next, α is a density value of about 1 to 20, and β is about 5 to 50.

α may be set to include the density of the platen, or may be set to include the white background of a normal document.

Also, even if β is determined by the accuracy of the photometric sensor,
It may be determined by a maximum density of 150 to 200 in a usual reflection development.

Further, α and β are within a predetermined concentration range, for example, α <20, β <
At 50, the frequency 0 on the histogram or the minimum frequency density value ( _DL , _DH in FIGS. 1 and 2) may be detected and used as the image area.

In addition, D _max , D _min , α, and β may be set during photometry or may be set in advance.

Next, the discriminant function used for discriminating the document type in the present invention will be described.

As a discriminant function for discriminating whether the color original to be the color image forming object is a photo original or a print original,
A linear discriminant function is preferred.

The linear discriminant function is, for example, when a plurality of samples belonging to each group of A and B have p characteristic values x, as a discriminant rule, Z = a ₁ x ₁ + a ₂ x ₂ + … ＋ A _i x _i ＋… ＋ a _p x _p (i = 1,2, ..., p) is used to create a synthetic variable Z, and the samples to be discriminated by the size of this Z are group A and group B. Which of the two belongs to.

Here, the coefficients a ₁ , a ₂ , ..., A _p are set so that the A group or the B group can be surely discriminated from concrete data, that is, A
The ratio between the variation S _B (inter-class variation) between the groups and the group B and the variation S _W (intra-class variation) of each of the groups A and B is determined so that S _B / S _W is the largest. .

In the image forming apparatus of the present invention, for each of the three primary color lights, a discriminant function using two types of sensors having sensitivity peaks at different wavelengths in each wavelength region and using these six types of measured values as parameters, Although a linear discriminant function is produced in particular, the wavelength sensitivity peak of the sensor used and the discriminant function are not particularly limited, but the concentration distribution curve shown in FIG. 3 will be described as a representative example.

FIG. 3 shows the spectral reflection densities of a color photographic image and a color printed image having an average color distribution. Solid line 2
What is shown by is a color photographic image, and what is shown by the dotted line 3 is a color print image.

As is clear from FIG. 3, the color photographic images have high densities near 400 nm and 450 nm.

Also, the magenta dye used for color photographic images has a maximum density (maximum absorption wavelength) near 530 to 560 nm,
The cyan dye has a maximum density around 630 nm. Further, both the cyan dye and the magenta dye have a characteristic that the concentration decreases around the maximum absorption wavelength.

On the other hand, magenta ink used for color printing images has a maximum density around 570 nm, and cyan ink has a nearly flat density up to around 600 to 680 nm.
At wavelengths longer than 700 nm, a sharper decrease in density is seen than in color photographic images.

As described above, the color photographic image and the color print image have different density distributions in the respective wavelength regions of the three primary color lights.

Therefore, a large number of color printing originals and color photographic originals are illuminated by a constant light source, and the reflected light thereof has a sensitivity peak in the vicinity of the wavelengths at which the characteristic maximum densities of the printing originals and photographic originals of the respective wavelength regions of the three primary color lights are shown. With, for example, the fourth
The linear density for the document type determination, which measures the reflection density or the absorption density with six types of sensors having the sensitivity characteristics shown in the figure, and uses this measured value as a parameter according to the above determination rule based on the measurement data By creating a function, it is possible to easily and accurately discriminate the document type of the color document to be image-formed by one linear discriminant function for obtaining Z.

A sensor having the sensitivity characteristic shown in FIG. 4, that is,
Sensor 150b ₁ and sensor 150b ₂ having sensitivity peaks at 400 and 450 nm in the B light wavelength region; Sensor 150g ₁ and sensor 150g ₂ having sensitivity peaks at 540 and 570 nm in the G light wavelength region; Sensor 150r ₁ and sensor 150r ₂ having sensitivity peaks at 630 and 700 nm; the image sensor 150 shown in FIG.
It was measured using a reflection density of a large number of color photographic original and color print original of a predetermined size, the sensor 150 r _1, sensor 150 g _1, the output value r1 of the sensor 150b _2, g1, b2 and sensor 150 r _1, 150 r ₂ output difference g2-g1 sensor output difference r1-r2, sensor 150 g ₂ and the sensor 150 g ₁ and
Using the output difference b ₂ -b ₁ and 150b ₂ and the sensor 150b ₁ as a parameter, according to the above-described determination rule can be made linear discriminant function shown below Discriminant Function 1].

Discriminant Function _{1] Z = a 1 + a} 2 * r 1 + a 3 * g 1 + a 4 * b 2 + a 5 * R + a 6 * G + a 7
^* B where R, G, and B are R = r1-r2, G, respectively.
= G1-g1 and B = b2-b1.

Further, the coefficients a _{1 to} a ₇ are determined so that the above-mentioned S _B / S _W ratio becomes the maximum between the print document and the photo document.

In addition, the threshold value Lp for color photo
The threshold value L _I between the color printed original and the color intermediate original can be determined by measuring a large number of samples.

For example, a halogen lamp rated at 80V and 150W is used as the light source, and the sensors 150r ₁ , 150r ₂ , 150g ₁ , 150g ₂ , 150b _{1 of the} image sensor 150 shown in FIG. 5 are used as the sensors.
And 150b ₂ were used to measure the reflection densities of 300 samples of A4 size color photographic originals and color printed originals respectively, and from this photometric value, the coefficient of the discriminant function 1 was determined.
When a _{1 to} a ₇ and thresholds L _P and L _I are defined, the following is obtained.

As the measurement value of each sensor, the reflected light of each original is 10
In the slit size of 100 mm x 100 mm, 70 points reflection density is measured every 3 mm for 210 mm in A4 size, and the average value r1, r2, g
1, g2, b1 and b2 are used.

_{a 1 = -14.33 a 2 = -} 0.11 a 3 = - 0.37 a 4 = 0.45 a 5 = 1.19 a 6 = - 0.67 a 7 = - 0.96 L I = - 5 L P = 5 At this time, in the present invention, photometric The values of the background density DB and the black skin density DBB that are excluded from the values are DB <10 and DBB> 200.

That is, in the above [discriminant function 1], Z ≦ −5
, The color original is determined to be a print original, and Z ≧ 5.
In this case, the original is determined to be a photographic original, and if -5 <Z <5, it is determined to be an intermediate original.

In the image forming apparatus of the present invention, the parameters used for the discriminant function are not limited to those described above, and six output values of each sensor are used as they are, not the difference between the primary color light wavelength regions but the sum. Various types such as those using may be applied.

However, in order to accurately discriminate between a photographic original and a printed original by a simple discriminant function, at least one measured value in each of the three primary color light wavelength regions and each primary color light wavelength region as in the above [discriminant function 1]. It is preferable to use the difference between the measured values inside as a parameter.

FIG. 6 shows an example in which the image forming apparatus of the present invention is applied to a silver salt photographic copying apparatus.

As shown in the figure, the silver salt photocopier 10 (hereinafter,
The copying machine 10 is provided with a photosensitive material supply unit 16 on the right side thereof, an exposure unit 18 above and a processing unit 20 below.

The [discriminant function 1] described above is provided in the exposure unit 18.
5 for manufacturing the image sensor 150 and the document discriminating section 152 for discriminating whether the document 130 is a photographic document or a printed document based on the measured values of the image sensor 150 by the above [discrimination function 1]. Are placed.

The document discriminating unit 152 controls the conveyance roller of the photosensitive material supplying unit 16 in the lens unit 92 or the device having an automatic sensitive material type selecting function as shown in FIG. Send to the system.

In the copying apparatus 10 of the present invention, this image sensor
The color original 130 is discriminated into at least a color print original and a color photographic original by the [discrimination function 1] by the 150 and the original discriminating unit 152, and the lens unit 92 is determined according to the discrimination result.
The predetermined amount of light and color density are adjusted according to the document type, or the photosensitive material supply unit 16 supplies a predetermined photosensitive material according to the document type.

The photosensitive material supply unit 16 has a photosensitive material feed path in a photosensitive material supply frame 28, and a pair of upper and lower magazines 30, 32 are detachably attached to the photosensitive material supply unit frame 28. Are housed in rolls, respectively, and are taken out to the photosensitive material supply unit 16 from the tip. As an example, 34 is a photosensitive material (for high contrast) which is most suitable for copying a color printing original which is a reflective original, and 36 is a soft material for soft contrast which is most suitable for copying a color photographic original.

In front of the magazine 30, conveying rollers 42a and 42b for pulling out the photosensitive material 34, and a cutter 44 for cutting the photosensitive material 34 into a predetermined length are arranged. Here, the transport rollers 42a and 42b receive a signal from the document discriminating section 152, and pull out the photosensitive material 34 according to the signal from the document discriminating section 152.

Photosensitive material transport guides 48a, 48b, 48c and transport rollers 50, 52 are arranged between the cutter 44 and the exposure section 46,
The cut photosensitive material 34 is guided to the exposure section 46.

The exposure section 46 is a section that defines the exposure position 46a (exposure surface) of the photosensitive material 34.
A glass plate 54 is fixed facing the imaging optical system of 18, and a pressing plate 56 is pressure-bonded to the glass plate 54.

A pair of transport rollers 58a, 58b and transport rollers 60a, 60b are provided on the upstream side (upper side) and the downstream side (lower side) of the exposure unit 46, respectively.

A conveyance guide 62 for vertically guiding the exposed photosensitive material 34 downward is arranged below the exposure section 46, and a conveyance path for the photosensitive material 34 (36) is branched at a middle portion in the vertical direction of the conveyance guide 62.
A switching guide 64 for switching to the processing unit 20 is provided.

On the other hand, the conveyance rollers 68a, 68b and the cutter 70 are arranged corresponding to the photosensitive material 36 in the magazine 32 arranged below the magazine 30, and the conveyance guides 72a, 72b and the conveyance roller 74 are arranged in front of them. Conveying photosensitive material 36 Guide 48a
Carry to. Incidentally, the conveyance rollers 68a, 68b receive a signal from the document discriminating section 152 similarly to the conveyance rollers 42a, 42b,
It is configured to pull out the photosensitive material 36 in response to a signal from the document discrimination section 152.

The exposure unit 18 is the most characteristic part of the copying apparatus 10, and is usually a document table 80 made of a transparent glass plate or the like on which a reflective document is placed, and a color document placed on the document table 80. Document holding plate 15 for fixing 130 and document table 80
A light source moving type imaging optical system 82 for performing slit scanning exposure of the above image on the photosensitive material 34 (36) of the exposure unit 46, and reflected light of the original 130 (hereinafter referred to as reflected light) during the prescan as described above. Image sensor 15 for measuring the reflection density of
0 and the measurement value of the image sensor 150 are used to determine whether the original 130 is a printed original or a reflective original by the [discrimination function 1], and the original type signal is sent to the lens unit 92 or the automatic sensing material as shown in FIG. In the apparatus having the kind selecting function, the document discriminating section 152 for sending to the conveying roller of the photosensitive material supplying section unit 16 and the exposure section 46 side and the image sensor 150 acting on the optical path L of the reflected light.
And a shutter 96 for switching the optical path L with the side. Here, the light source moving type imaging optical system 82 is moved in the same direction as a light source unit having a light source 84 for scanning the lower surface of the original table 80 and a reflection mirror 86, and at a speed half that of the light source unit. A mirror that reflects the light from the light source 84 in a predetermined direction
It is composed of 88, 90 and a lens unit 92.

The lens unit 92 exposes the reflected light of the original 130 to the exposure position 46a.
A front group 154 and a rear group 156 of lenses for imaging
A cyan filter C, a yellow filter Y, and a magenta filter M corresponding to cyan, yellow, and magenta colors for correcting the color of reflected light, and diaphragm plates 158 and 160 as variable diaphragms for correcting the amount of reflected light. Have and.

Then, in the copying apparatus 10 of the present invention, this lens unit 92 is connected to the document discriminating section 152, and the document discriminating section 152 is connected.
In accordance with the original type signal, the light amount and color of the reflected light are adjusted by a predetermined amount according to the original type of the color original 130.

This correction of reflected light is performed, for example, when the user selects a high contrast photosensitive material and the color original 130 is a color printing original, copying is performed under the standard setting conditions for high contrast, but the color original 130 is a color photographic original. If it is, the yellow filter Y is removed and correction is performed to increase the light amount.

If the user selects a high contrast photosensitive material and the color original 130 is a color photographic original, copying is performed under the standard condition setting for soft adjustment, but if it is a color print original, the cyan filter C is used. Corrected to include.

The light source moving type imaging optical system 82 applied to the copying apparatus 10 is configured to be capable of zoom copying with a magnification of 0.5 to 2.0.

The shutter 96 is for changing the optical path L of the reflected light between the prescan and the exposure, and is in the closed state shown by the solid line in the figure during the prescan, and the optical path L of the reflected light is changed to the image sensor 150 side. At the time of exposure, the open state shown by the dotted line in the figure is set so that the reflected light exposes the photosensitive material 34 (36).

The image sensor 150 measures the density of the reflected light of the original 130 and is the same as the one used in the production of the [discriminant function 1] described above. The sensor 150b ₁ and the sensor 150b ₂ shown in FIG. , Sensor 150g ₁ , sensor 150g ₂ , sensor 150r ₁ and sensor 150r ₂ in total, and a condenser lens such as a Fresnel lens for condensing reflected light.

The measurement value of the image sensor 150 is sent to the document discriminating unit 152.

The document determination unit 152 uses the measurement value of the image sensor 150 to
In the above [discrimination function 1], it is determined whether the color original 130 is a color photographic original or a color printed original, and the original type signal is sent to the lens unit 92 or an apparatus having an automatic sensitive material type selecting function as shown in FIG. , To the photosensitive material supply unit 16. Such a document discriminating section 152 has the configuration shown in FIG.

The measurement value of the image sensor 150 is sent to the amplifier 170 as an output signal, amplified by the amplifier 170, and then A / D.
The converter 172 converts the density signal.

The two types of density signals obtained for each color are sent to the RAM 176 via the photometric data processing device 174.

After the pre-scan, the photometric data processing device 174 reads out two kinds of density signals of each color from the RAM 176 and sends them to the color document discriminating device 178, where the color document type is discriminated.

Then, the signal of this color original type is sent to the lens unit 92.
Alternatively, as shown in the figure, in an apparatus having an automatic sensitive material type selection function, the material is sent to the photosensitive material supply unit 16, and the lens unit 92 is set to a predetermined reflected light adjustment condition according to the type of the color original, or The photosensitive material supply unit 16 supplies a photosensitive material according to the type of color original document.

The processing unit 20 includes a processing unit 22 and a drying unit 24. A developing tank 102, a bleaching / fixing tank 104, and water washing tanks 106, 108 are continuously provided in the processing section 22, and a photosensitive material 34 (developed, bleached, fixed, washed with a processing solution filled in the inside thereof) ( 36) is sent to the drying section 24.

The drying section 24 is configured to dry the photosensitive material 34 (36) after washing with water and send it out onto the take-out tray 110.

In the copying apparatus 10 described above, the image sensor 150 is used for determining the original document type, but the present invention is not limited to this. The image sensor 150 measures various kinds of image information and the lens unit is used. It goes without saying that the correction of reflected light in accordance with this image information may be added at 92.

Further, the image forming apparatus of the present invention is not limited to the silver salt photographic copying apparatus as described above, but also a copying apparatus using various photosensitive materials such as a photosensitive pressure-sensitive photosensitive material and a photosensitive material resin material, and an electrophotographic type copying apparatus. The present invention can be suitably applied to various copying apparatuses such as copying apparatuses, and various printers.

The image forming apparatus according to the present invention is basically configured as described above, and its operation will be described below.

In the copying machine 10 shown in FIG. 6, the color original 130 is placed on the original table 80 and the original pressing plate 15 is closed.

Next, when a copy start button (not shown) of the copying apparatus 10 is pressed, the light source 84 is turned on to illuminate the color original 130, the light source unit starts scanning, and pre-scanning is started.

The reflected light of the color original 130 is incident on the mirror 86 of the light source unit that moves at the scanning speed, is reflected, and then is reflected by the mirrors 88 and 90 that move in the same direction as the light source unit at half the scanning speed. , The shutter which passes through the lens unit 92 and is arranged in the optical path L at the position shown by the solid line in FIG.
Image sensor 1 reflected by 96 and mirror 148
Incident on 50.

At this time, the filters and diaphragms of the lens unit 92 do not act on the optical path L, and are in a plain state.

The reflected light incident on the image sensor 150, the reflected light intensity at each wavelength is measured at six sensors of the sensor 150 r ₁ ~ sensor 150b _2.

The measurement value of the image sensor 150 is sent to the document discriminating unit 152. In the original discriminating unit 152, the measured value is processed by the above-mentioned [discrimination function 1] to discriminate the color original 130 into at least a color photographic original and a color printed original, and the original type signal is sent to the lens unit 92 or In an apparatus having an automatic sensitive material type selection function, the material is sent to the photosensitive material supply unit 16.

After the prescan, the light source unit and the mirror
8, 90 returns to the scanning start position.

On the other hand, in the lens unit 92, a predetermined light amount and color density correction are performed according to the document type in accordance with the above-mentioned document type signal, or in a device with an automatic sensitive material type selection function, a photosensitive material is used. In the supply unit 16, a photosensitive material is selected according to the document type.

As an example, if the color original 130 is a color photographic original when the user selects the high-sensitivity photosensitive material 34, the lens unit 92 removes 6 cc of the filter Y with respect to the standard condition for high-accuracy and changes the variable aperture. Adjusted to open about 9cc.

On the other hand, in the photosensitive material supply unit 16, when the high-contrast photosensitive material 34 is selected and the transport motor (not shown) is driven, the transport rollers 42a and 42b feed the photosensitive material 34 by a predetermined length, and the cutter 44 is used. The photosensitive material 34 is cut to the required length. After that, the conveying motor is driven again and the photosensitive material 34 is sent to the exposure section 46, and stands by immediately before the exposure position 46a.

When the shutter 96 rotates to the position shown by the dotted line in FIG. 6 to enable exposure and the light source unit starts the main scanning, at the same time, the transport rollers 58a, 58b and 60a, 60b of the exposure section 46 move to the photosensitive material 34. The scanning conveyance is started in synchronization with the scanning speed of the light source 84.

During the main scan, the reflected light that is incident on and reflected by the mirror 86 that moves at the scanning speed is reflected by the mirrors 88 and 90 that move in the same direction at half the speed of the mirror 86, and the color and diaphragm are different from each other. Passing through the lens unit 92, which is suitably adjusted according to
The photosensitive material 34, which is imaged at the exposure position 46a (exposure surface) and is synchronously scanned and conveyed, is exposed.

As the exposure progresses, the photosensitive material 34 is transferred to the transport roller 58a,
From between 58b and 60a, 60b, it is sent downward through the transport guide 62. In this case, the switching guide 64 does not act on the photosensitive material conveying path, and the photosensitive material 34 sent from the exposure unit 46 moves vertically downward in the conveying guide 62. Therefore, there is no slack in the intermediate portion of the photosensitive material 34 due to the speed difference between the photosensitive material supply unit 16 and the processing unit 22 due to the exposed photosensitive material 34 being sent to the processing unit 22 of the processing unit 20.

When all the exposure is completed, the shutter 96 is rotated to the position shown by the solid line in FIG. 4, each transport roller is temporarily rotated in the opposite direction, and the exposed photosensitive material 34 moves up the transport guide 62 and partially. Are sent into the transport guide 48c.

In the reverse conveyance, the tip of the photosensitive material 34 is used as a switching guide.
It will be stopped upstream of 64.

After that, the respective transport rollers are again rotated in the same direction as the initial transport direction. In this case, the switching guide 64 acts on the photosensitive material conveying path to branch the leading end of the photosensitive material 34 from the conveying guide 62 and send it to the branch conveying guide 66. Therefore, the leading end of the photosensitive material 34 is sent to the processing section 22 of the processing section unit 20 through the branch conveyance guide 66.

The exposed photosensitive material 34 sent into the processing section 22 is the developing tank 102.
Developed, then bleached / fixed in the bleaching / fixing tank 104, and sufficiently washed in the washing tanks 106 and 108, and then the drying section 2
4 and is taken out onto the take-out tray 110 after being dried.

In the copying apparatus 10 shown in FIG. 6 using the sensor 150 shown in FIG. 5, two types of E-size color photographic originals were placed on the original placing table and 200% enlarged copying was performed. The prescan was performed for A4 size.

It discriminates by the above-mentioned discriminant function 1 using the photometric values of the above-mentioned 6 sensors by the prescan. When the value Z of the discriminant function 1 is Z ≧ 5, it is determined that the color photo original, Z ≦ −5, the color print original, and −5 <Z <5, the intermediate type original.

In the example of the present invention, when the background density DB ≧ 10, it is determined using all image data information obtained by prescanning,
When DB <10, the image data in the background area was excluded from the calculation for determination.

In the comparative example, the discrimination operation was performed using all the image data without selecting the image data based on the background density.

 The results are shown in Table 1.

As described above, in the case of enlarging and copying a small color photo original such as E size, the pre-scanning is performed corresponding to the A4 size at 200% enlargement according to the photosensitive material. Although the reflected light from the white surface of the plate is also input to the sensor, in the present invention example, since the original type is determined by excluding the photometric value of the level corresponding to the reflected light from the white surface, the conventional intermediate type original or Even a small-sized photo original that was determined to be close to the printed original was correctly determined to be a photo original.

Next, in the same way, 100
The sample type and the color photographic document were used to determine the document type by the image forming apparatus of the present invention. The results are shown in FIG.

As is apparent from FIG. 8, among 100 samples of color printing originals, 7 samples were determined to be intermediate type originals, the rest were determined to be color printing originals, and none were determined to be color photographic originals.

On the other hand, out of the 50 samples of the color photographic originals, 7 were found to be the intermediate type originals, the rest were all correctly identified as the color photographic originals, and none were identified as the color printed originals.

As is clear from the above results, since the image forming apparatus of the present invention can correctly determine the document type, it is possible to improve the color tone and image quality of the formed image.

<Effects of the Invention> As described above in detail, according to the present invention, the reflected light from the photometric area including the color original is photometered to obtain a color photographic original and a color printed original based on the photometric value. At the time of the determination, the determination operation is performed by excluding the photometric values below a predetermined low level and / or above a predetermined high level from the photometric value. There is no dent or original to measure the white surface of the image as an image, a thick copy of a color original, or a large dent on the package or three-dimensional object, or to measure light using the original holding plate. Even if the area is metered, at least the color photographic original and the color printed original can be accurately determined, so that it is possible to form a high-quality image having a good color tone according to the type of the original.

Therefore, the image forming apparatus of the present invention is extremely effective at the time of enlargement copying.

Furthermore, by using the image forming apparatus of the present invention,
Even when a person who does not have specialized knowledge about the discrimination of the document type forms an image, regardless of the size of the document size, regardless of the form of the document, the exposure amount is automatically and appropriately corrected according to the document type. Since color correction can be performed and an image can be formed by selecting a suitable photosensitive material, good image formation can always be performed.

[Brief description of drawings]

FIG. 1 is a histogram of photometric density when a color original smaller than the photometric area is photometrically measured in the image forming apparatus of the present invention. FIG. 2 is a histogram of photometric densities obtained when photometry is performed on a color original having a photometric area dent or an area without an original in the image forming apparatus of the present invention. FIG. 3 is a graph showing the spectral reflection densities of a color photographic image and a color printed image. FIG. 4 is a graph showing the sensitivity characteristics of the sensor applicable to the image forming apparatus of the present invention. FIG. 5 is a schematic diagram of an example of an image reader applied to the present invention. FIG. 6 shows an embodiment in which the image forming apparatus of the present invention is applied to a silver salt photographic copying apparatus. FIG. 7 is a schematic diagram showing the configuration of the document discriminating section of the silver salt photographic copying apparatus shown in FIG. FIG. 8 is a graph showing the result of color document discrimination in the image forming apparatus of the present invention. Explanation of symbols 10 …… Copier, 15 …… Original plate, 16 …… Photosensitive material supply unit, 18 …… Exposure unit, 20 …… Processing unit, 22 …… Processing unit, 24 …… Drying unit , 26 …… Spare solution storage section, 28 …… Sensitive material supply section frame, 30,32 …… Magazine, 34,36 …… Sensitive material, 38 …… Opening / closing lid, 40,100 …… Pin, 46 …… Exposure section, 46a ... exposure position, 54 ... glass plate, 56 ... pressing plate, 58a, 58b, 60a, 60b ... conveying roller, 64 ... switching guide, 80 ... document table, 82 ... imaging optical system, 84 ... Light source, 86, 88, 90 ... Mirror, 92 ... Lens unit, 96 ... Shutter, 98 ... Exposure section frame, 102 ... Developing tank, 104 ... Bleaching / fixing tank, 106, 108 ... Washing with water Tank, 110 …… Tray, 130 …… Color original, 148 …… Mirror, 150 …… Image sensor, 152 …… Document discriminating section, 154 …… Lens front group, 156 …… Lens Group, 158, 160 ...... diaphragm plate, C ...... cyan filter, Y ...... yellow filter, M ...... magenta filter

Claims (1)

(57) [Claims] 1. A reflected light in a predetermined photometric area including a color original is measured, at least the original types of a photo original and a print original are discriminated from the obtained photometric value, and an image is formed according to the color original. An image forming apparatus, wherein in the image forming apparatus, an operation of discriminating a document type is performed by removing photometric values below a predetermined low level and / or above a predetermined high level from the photometric values.