JP2006261819A - Imaging apparatus, image forming apparatus, and reading method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology of capable of reading a region providing a metallic color in an object to be imaged and reproducing the read color. <P>SOLUTION: An image reading section 10 of an image forming apparatus 1 reads an image signal (color signal) on the basis of a diffusion reflection light of 45° incidence and 0° reflection, and an image signal (luster signal) on the basis of regular reflection of 45° incidence and 45° reflection. The image forming apparatus 1 compares the color signal with the luster signal to generate luster information denoting a region showing the luster on the object to be imaged, and provides the information to image data representing the object to be imaged. An image forming section 20 of the image forming apparatus 1 forms a toner image on recording paper on the basis of the image data. The image forming apparatus 1 in this case forms a toner image having the metallic color on the region denoting the luster information. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for reading a so-called metallic color such as gold or silver and reproducing it.

  In offices and general homes, there is an increasing demand for reproducing a metallic color included in a subject (object to be imaged) using a scanner or a printer. For example, there is such a request when an object to be imaged such as a fabric woven with gold yarn or silver yarn or an electronic device with metallic coating is read and printed by a scanner. Printing the metallic color itself is realized by using a metallic color material as a special color regardless of the recording method. However, a general scanner used in an office or a general household cannot faithfully scan an area showing a metallic color (hereinafter referred to as “metallic area”) in an object to be imaged. This is because the surface reflection light generated from the metallic region contains almost no diffuse reflection light, and most of it is regular reflection light.

  In general, a scanner acquires color information of an object to be imaged by reading diffuse reflected light. This is because if the specular reflection light is read when acquiring the color information of the object to be imaged, the contrast of the color information is lowered particularly when reading the object to be imaged with high glossiness, and accurate color information can be acquired. Because it disappears. For this reason, a scanner usually irradiates the object to be imaged with an incident angle of 45 °, and reads reflected light having a reflection angle of 0 ° from the object to be imaged. However, as described above, since the surface reflection light generated from the metallic region contains almost no diffuse reflection light, the color information of the metallic region obtained by the scanner is low regardless of the color of the region itself. Shows a light blackish color.

Therefore, in order to reproduce the metallic region of the object to be imaged, it is necessary to read not only the diffusely reflected light from the object to be imaged but also the specularly reflected light and detect the presence or absence of the gloss. A technique for detecting the gloss of an object to be imaged has been conventionally known. For example, Patent Document 1 discloses an example thereof.
JP-A-6-70097 (FIG. 1 etc.)

  However, the technique described in Patent Document 1 detects a region showing gloss by detecting a specularly reflected light component from a document as an object to be picked up by the optical sensor 17, and corrects this region. is there. In other words, since this is a technique for removing gloss, it is naturally impossible to know which area of the object to be imaged is glossy by using such a technique.

  In addition, when a close-contact optical system such as that disclosed in Patent Document 1 is employed in a scanner, the depth of focus becomes shallow, so the object to be imaged must have high flatness. However, the surface of the woven fabric or electronic device as described above often has unevenness due to the steps of the weave pattern, operation buttons, and the like. When such an object to be imaged is read by the contact optical system, blurring occurs, and there is a problem that an image of a certain quality cannot be obtained before the gloss is detected.

  Furthermore, even if image data read using such a technique is printed by an image forming apparatus such as a printer, this image forming apparatus is simply an area with a high reflectance (an area close to white) in the image data. ) And the metallic region cannot be distinguished from each other, and the metallic region is simply expressed by a color close to white. That is, after all, it is impossible to reproduce the metallic area of the object to be imaged with such image data.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a mechanism that makes it possible to read a region showing a metallic color on an object to be imaged and reproduce it.

In order to solve the above-described problems, the present invention provides an irradiating unit that irradiates light on an object to be imaged and an image of diffuse reflected light from the object to be imaged that is generated when the irradiating unit irradiates light. A first imaging unit; a second imaging unit that forms an image of specularly reflected light from the imaging object that is generated when the irradiation unit irradiates light; and the first or second imaging unit. From the first image signal generated by the imaging unit according to the diffused reflected light and the imaging unit that receives the formed light and generates an image signal according to the light, the object to be imaged Metallic information indicating a glossy region on the object to be imaged is generated from an image data generating unit that generates image data to be displayed and a second image signal generated by the imaging unit in response to the regular reflection light. Metallic information generation means The metallic information the metallic information generated by the generating means and applying the image data generated by the image data generating unit, an imaging device and an output means for outputting the image data.
According to this imaging apparatus, it is possible to acquire metallic information representing an area showing a metallic color and assign it to image data, so that an area showing a metallic color can be distinguished from other areas.

In the imaging apparatus, the metallic information generation unit calculates a gloss level for each pixel represented by the second image signal, and applies the metallic information to an area on the imaged object that exceeds the determined gloss level. It is good also as composition to generate.
By adopting such a configuration, it is possible to provide a level delimited for each gloss level in the area showing the metallic color, so that the area showing the metallic color can be expressed by changing the degree of gloss. It becomes.

Further, in this imaging apparatus, the first imaging means forms an image of diffuse reflection light having a reflection angle from the imaging object of −5 ° to 5 °, and the second imaging means includes: It is desirable that the regular reflected light having a reflection angle from the object to be imaged of 40 ° to 50 ° is imaged.
By adopting such a configuration, it becomes possible to read diffuse reflection light and regular reflection light well.

  The present invention includes an irradiating unit that irradiates light to an object to be imaged, a first image forming unit that forms an image of diffuse reflected light from the imaged object that is generated when the irradiating unit irradiates light, A second imaging unit that forms an image of specularly reflected light from the object to be imaged as a result of the irradiation unit irradiating light, and a light imaged by the first or second imaging unit, respectively. An image for generating image data indicating the object to be imaged from an imaging unit that receives light and generates an image signal corresponding to the light, and a first image signal generated by the imaging unit according to the diffuse reflection light Data generation means; metallic information generation means for generating metallic information indicating a glossy region on the object to be imaged from the second image signal generated by the imaging means in response to the specularly reflected light; and Metallic information student The metallic information generated by the image forming unit is attached to the image data generated by the image data generating unit, and the recording material is supplied with toner based on the image data supplied by the supplying unit and the image data supplied by the supplying unit. The image forming apparatus includes an image forming unit that forms an image.

In this image forming apparatus, the image forming unit may be configured to form a toner image with metallic toner in an area indicated by the metallic information.
With such a configuration, it is possible to form an image using a metallic toner in a region showing a metallic color, and it is possible to more faithfully represent the object to be imaged.

Further, in this image forming apparatus, the image forming unit can form a toner image with at least two or more metallic toners, and the toner color of the toner image formed in the area indicated by the metallic information is changed to the metallic color. The image data may be determined based on the color information of the area of the image data corresponding to the area indicated by the information.
With such a configuration, it is possible to color-code a region showing a metallic color with a metallic color.

In the image forming apparatus, the image forming unit may form a toner image using a transparent toner in an area indicated by the metallic information.
By adopting such a configuration, it is possible to reproduce a region showing a metallic color with higher gloss.

  In the present invention, the step of irradiating the object to be imaged to generate a first image signal corresponding to the diffusely reflected light, irradiating the object to be imaged with light, and corresponding to the specularly reflected light A step of generating a second image signal; a step of generating image data indicating the object to be imaged from the first image signal; and a gloss on the object to be imaged from the second image signal. It is also specified as a method for reading an object to be imaged comprising: generating metallic information indicating a region; and adding and outputting the metallic information to the image data.

  As described above, according to the present invention, it is possible to read a region showing a metallic color on an object to be imaged and reproduce it.

[1: Configuration]
FIG. 1 is a diagram showing a device configuration of an image forming apparatus 1 according to an embodiment of the present invention. The image forming apparatus 1 reads a non-imaging object such as paper, fabric, or metal to generate image data, and forms a toner image on a recording material such as recording paper based on the image data. The image forming unit 20 is roughly classified. The image reading unit 10 corresponds to a so-called scanner, and the image forming unit 20 corresponds to a so-called printer. That is, the image forming apparatus 1 is a so-called multi-function machine having functions of a scanner and a printer.
The image forming apparatus 1 according to the present embodiment has various characteristics for reading a metallic region in an object to be imaged and expressing it as a toner image. First, the configuration of the image forming apparatus 1 will be described in detail with the image reading unit 10 and the image forming unit 20 shown in the drawings. In addition, the functional configuration of the image forming apparatus 1 will be described.

Here, before describing the configuration of the image forming apparatus 1, the type of light read by the image forming apparatus 1 will be described.
FIG. 2 is a diagram conceptually showing a reflection state of light from the object to be imaged. In general, light incident on an object to be imaged at an incident angle θ ₁ is reflected at a reflection angle θ ₂ , and at this time, it is understood that the reflection angle θ ₂ is equal to the incident angle θ ₁ (reflection law). In practice, however, incident light is not reflected only at the reflection angle θ _2, but is often reflected at any angle. This is because when the reflecting surface is captured on the same order as the wavelength of light, the reflecting surface is not necessarily smooth and often has some unevenness. Of course, if the reflecting surface has irregularities, incident light is also reflected at various angles according to the irregularities.

Here, when the reflection surface is viewed macroscopically, the reflection reflected from the reflection surface at the same angle as the incident angle is called “Specular Reflection”, and this reflected light is referred to as “regular reflection”. It is called “light”. In addition, the reflection reflected from the reflection surface at any angle regardless of the incident angle of the incident light is called “diffuse reflection”, and the reflected light is called “diffuse reflected light”. In the drawings shown below, these are distinguished by attaching a symbol L _sr to an optical path representing regular reflected light and a symbol L _dr to an optical path representing diffusely reflected light, as necessary.

In the present embodiment, the “metallic region” is a region that has a lot of regular reflection components in the surface reflected light and has a glittering feeling in the object to be imaged. This glittering feeling is brought about by a glittering material such as metal powder contained in the paint if the surface of the object to be imaged is subjected to, for example, metallic coating. Similarly, a metal surface such as a gold thread, a silver thread, or a matte (matte) finish also brings a glittering feeling due to the surface properties of the material used as the material.
Although the color indicated by the metallic region is various, here, for convenience of explanation, the color indicated by the metallic region is limited to two types of “gold” and “silver”.

[1-1: Configuration of Image Reading Unit 10]
Here, the configuration of the image reading unit 10 will be described with reference to FIG. The image reading unit 10 includes a full rate carriage 110, a half rate carriage 120, an imaging lens 130, a line sensor 140, a platen glass 150, and a platen cover 160. The configuration of each part will be described below.

  FIG. 3 is a diagram showing the configuration of the full rate carriage 110 in detail. The full rate carriage 110 includes a light source 111, mirrors 112, 113 and 114, and a rotating reflector 115. The light source 111 is a single light source having a spectral energy distribution over the entire visible light region, such as a tungsten halogen lamp or a xenon arc lamp. The light source 111 irradiates the object to be imaged O with an incident angle of about 45 °. The mirrors 112, 113, and 114 reflect the reflected light from the object to be imaged O and guide this light to the half-rate carriage 120. The position of the mirror 112 is adjusted so that the reflected light having a reflection angle from the object to be imaged O of about 0 ° is incident, and the mirror 113 is the reflected light having a reflection angle from the object to be imaged of about 45 °. Is adjusted so as to be incident.

As described above, the incident light on the mirror 112 is reflected light of about 0 °, more specifically about 0 ± 5 °. Reflected light reflected at this angle does not include specularly reflected light, but only diffusely reflected light. Therefore, the diffuse reflection component of the reflected light from the object to be imaged O can be read from the optical path L _dr reflected by the mirror 112.
On the other hand, the incident light on the mirror 113 is reflected light of about 45 °, more specifically about 45 ± 5 °. Most of the reflected light reflected at this angle is specularly reflected light. Therefore, the regular reflection component of the reflected light from the imaging target O can be read from the optical path L _sr reflected by the mirror 113.

  Note that the optimum position of the mirror 113 differs depending on the material of the object to be imaged O to be read. If the object to be imaged O is mainly an object having a low glossiness, the reflection angle incident on the mirror 113 is preferably exactly 45 °, and if the object to be imaged O is an object having mainly a high glossiness, The incident reflection angle is desirably slightly deviated from 45 °. This is because the surface reflected light from an object with high glossiness is high in intensity, and there is a possibility that the input exceeds the dynamic range of a CCD (Charge Coupled Device) image sensor, that is, the reading limit of the line sensor 140.

  The rotating reflector 115 is a mirror 115m that reflects light on one side, and an optical trap 115t that absorbs light on the other side. The light trap 115t is, for example, a black and porous polyurethane sheet, and most of the light incident thereon is trapped (absorbed) on the surface and absorbed.

When the rotating reflector 115 is at the position shown in FIG. 3, the light from the mirror 112 is reflected and guided to the half-rate carriage 120, while the light from the mirror 114 is absorbed. Further, the rotating reflector 115 is rotated around the axis 115a by a driving unit (not shown), and can be moved to a position indicated by a dotted line (115 ′) in the drawing. When in this position, the rotating reflector 115 guides light from the mirrors 113 and 114 to the half-rate carriage 120 and absorbs light directed to the mirror 112.
The light reflected by the rotating reflector 115 has the same optical path as the light reflected by the mirror 114. By doing in this way, it becomes possible to receive two types of different reflected light with the same imaging means (line sensor 140).

  The configuration of the full rate carriage 110 is as described above. The full-rate carriage 110 is driven by a drive unit (not shown) and reads the object to be imaged O while being moved in the direction of arrow C in FIG. 1 at a speed v (hereinafter, this operation is referred to as “scanning operation”). ). Next, referring to FIG. 1 again, the other units of the image reading unit 10 will be described.

  The half-rate carriage 120 includes mirrors 121 and 122 and guides light from the full-rate carriage 110 to the imaging lens 130. The half-rate carriage 120 is driven by a drive unit (not shown) and is moved in the same direction as the full-rate carriage 110 at half the speed (ie, v / 2) of the full-rate carriage 110.

The imaging lens 130 is an imaging means including, for example, an fθ lens. The imaging lens 130 is provided on an optical path connecting the mirror 122 and the line sensor 140, and forms an image of light from the object to be imaged O at the position of the line sensor 140.
The imaging lens 130 is not limited to a single lens and may include various members. In the present embodiment, mirrors, lenses and the like existing on the optical path of the reflected light are collectively referred to as “imaging means (for imaging the reflected light)”. The mirror 112, the rotating reflector 115, the half-rate carriage 120, and the imaging lens 130 constitute imaging means for forming an image of diffusely reflected light. The mirrors 113, 114, the rotating reflector 115, the half-rate carriage 120, and the connection are formed. The image lens 130 forms image forming means for forming an image of the regular reflection light.

  The line sensor 140 generates and outputs an image signal corresponding to the intensity of the imaged light. The line sensor 140 is an image pickup unit that can simultaneously receive light of different wavelengths, and is, for example, a multi-line CCD image sensor (image pickup element array) including an on-chip color filter. This CCD image sensor images an object to be imaged with different spectral sensitivities for each line. In the present embodiment, an image sensor capable of imaging with three colors of R (red), G (green), and B (blue) is used. The line sensor 140 of this embodiment outputs the image signals of these three colors with 8 bits for each color.

  The platen glass 150 is a transparent and flat glass plate on which an object to be imaged O to be read is placed. A reflection suppressing layer such as a multilayer dielectric film is formed on both surfaces of the platen glass 150 so that reflection on the surface of the platen glass 150 is reduced. The platen cover 160 is provided so as to cover the platen glass 150 and blocks external light to facilitate reading of the object to be imaged O placed on the platen glass 150.

  With the above configuration, in the image reading unit 10, the light source 111 irradiates the object to be imaged O placed on the platen glass 150, and the reflected light is read by the line sensor 140. The line sensor 140 supplies image signals of four colors R, G, and B to the image processing unit 50 described later based on the read reflected light. The image processing unit 50 generates image data based on the image signal and supplies the image data to the image forming unit 20.

  The image reading unit 10 of the present embodiment is configured to output different image signals depending on the type of reflected light. Specifically, the image reading unit 10 includes diffuse reflected light (45 ° incidence, 0 ° reflection) due to light from the light source 111 and regular reflected light (45 ° incidence, 45 ° reflection) due to light from the light source 111. An image signal based on two types of reflected light is output. For this reason, the image reading unit 10 performs two scanning operations when reading the object to be imaged O.

[1-2: Configuration of Image Forming Unit 20]
Next, the configuration of the image forming unit 20 will be described. The image forming unit 20 includes developing mechanisms 210a, 210b, 210c, and 210d, an intermediate transfer belt 220, primary transfer rolls 230a, 230b, and 230c, a secondary transfer roll 240, a backup roll 250, and a paper feed mechanism 260. And a fixing mechanism 270.

FIG. 4 is a diagram showing the configuration of the developing mechanism 210a in more detail. The developing mechanism 210a is a so-called rotary developing device, and includes a photosensitive drum 211a, a charger 212a, an exposure device 213a, and developing units 214a, 215a, 216a, and 217a. The photosensitive drum 211a is an image carrier having a photoconductive layer made of OPC (Organic Photo Conductor) as a charge acceptor on the surface thereof, and is rotated in the direction of arrow A in the figure. The charger 212a includes, for example, a power source and a charging roller, and uniformly charges the surface of the photosensitive drum 211a. The exposure device 213a irradiates light to the photosensitive drum 211a with, for example, a laser diode, and forms an electrostatic latent image with a predetermined potential. The developing units 214a, 215a, 216a, and 217a store toners of different colors, and form toner images by attaching toner to the electrostatic latent image formed on the surface of the photosensitive drum 211a. The toners stored in the developing units 214a, 215a, 216a, and 217a are, for example, four color toners of Y (yellow), Au (gold), Ag (silver), and I (transparent). Here, the transparent toner is a toner that does not contain a color material. For example, a low molecular weight polyester resin is externally added with SiO ₂ (silicon dioxide) or TiO ₂ (titanium dioxide).

On the other hand, the developing mechanisms 210b, 210c, and 210d include single color developing devices 214b, 214c, and 214d. Since the photosensitive drums 211b, 211c, and 211d, the chargers 212b, 212c, and 212d, and the exposure devices 213b, 213c, and 213d have substantially the same configuration as the developing mechanism 210a described above, description thereof is omitted. To do. The developing mechanisms 210b, 210c, and 210d respectively create four color toner images, for example, M (magenta), C (cyan), and K (black).
The developing mechanisms 210a, 210b, 210c, and 210d may be stored in an arbitrary order in an arbitrary place regardless of the color of the toner to be stored.

  Here, with reference to FIG. 1 again, another configuration of the image forming unit 20 will be described. The intermediate transfer belt 220 is an endless belt member that is moved in the direction of arrow B in the drawing by a driving unit (not shown). The intermediate transfer belt 220 transfers the toner image (primary transfer) at a position facing the photosensitive drums 211a, 211b, 211c, and 211d, and moves the toner image to transfer the toner image onto the recording paper P (secondary transfer) again. The primary transfer rolls 230a, 230b, 230c, and 230d urge the intermediate transfer belt 220 with appropriate pressure at positions where the intermediate transfer belt 220 faces the photosensitive drums 211a, 211b, 211c, and 211d, and transfer the toner image to the intermediate transfer belt 220. . The secondary transfer roll 240 and the backup roll 250 are urged with an appropriate pressure at a position where the intermediate transfer belt 220 faces the recording paper P, and transfer the toner image onto the recording paper P. The paper feed mechanism 260 includes paper trays 261a and 261b that accommodate various recording papers P, and supplies the recording papers P during image formation. The fixing mechanism 270 includes a roll member for heating and pressurizing the recording paper P, and the toner image transferred onto the surface of the recording paper P is fixed by heat and pressure and then discharged.

  Based on the above configuration, the image forming unit 20 forms an image on the recording paper P using the above-described seven color toners based on the image data input from the image processing unit 50. At this time, the image forming unit 20 changes the image forming process in accordance with an instruction from the control unit 30 described later. Specifically, if the input image data is image data including a metallic area, the image forming unit 20 forms a toner image with gold toner or silver toner in that area.

[1-3: Functional Configuration of Image Forming Apparatus 1]
Subsequently, a functional configuration of the above-described image forming apparatus 1 will be described.
FIG. 5 is a block diagram functionally showing the configuration of the image forming apparatus 1. The image forming apparatus 1 includes a control unit 30, a storage unit 40, an image processing unit 50, an operation unit 60, and a data input / output unit 70 in addition to the image reading unit 10 and the image forming unit 20 described above. Yes.

  The control unit 30 is an arithmetic unit including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like (not shown), and executes various programs PRG stored in the storage unit 40. Thus, the operation of each part of the image forming apparatus 1 is controlled. The storage unit 40 is a large-capacity storage device such as an HDD (Hard Disk Drive), for example. In addition to the various programs PRG for operating each unit of the image forming apparatus 1 described above, the glossiness of the object to be imaged of various materials Is stored in the glossiness determination table TBL.

Here, the contents of the glossiness determination table TBL will be described.
FIG. 6 shows an example of the data structure of the glossiness determination table TBL. In the glossiness determination table TBL, there are data relating to the reflected light intensity of the diffusely reflected light of various objects and level values (hereinafter referred to as “glossiness level”) indicating the glossiness corresponding to the reflected light intensity. is described. This reflected light intensity is, for example, a metric brightness (L *) in the CIELAB color system, and is described here as an 8-bit value from “0” to “255”. Further, the gloss level indicates that the larger the value, the higher the glossiness of the object to be imaged. In this embodiment, the gloss level is divided into 10 levels from “1” to “10”. Yes. These data are experimentally specified and stored in advance. Note that the specific value of the gloss level may be arbitrarily determined by the operator of the image forming apparatus 1.

  Here, the description of the configuration of the image forming apparatus 1 will be continued with reference to FIG. The image processing unit 50 includes a plurality of image processing circuits such as ASIC (Application Specific Integrated Circuit) and LSI (Large Scale Integration), an image memory for temporarily storing image data, and the like. The image processing is executed. Image processing here refers to basic image processing such as AD conversion, shading correction, and gamma conversion, as well as various processing such as color space conversion, image rotation, image enlargement / reduction, background removal (UCR) processing, and screen processing. Furthermore, it includes processing for generating metallic information.

  The image processing unit 50 performs such image processing on the image signal generated by the image reading unit 10 to generate image data. The image processing unit 50 supplies the generated image data to the image forming unit 20. The operation unit 60 includes, for example, a touch panel display, various buttons, and the like, and receives an input instruction from an operator of the image forming apparatus 1. This input instruction is supplied to the control unit 30. The data input / output unit 70 is an interface device for exchanging data with an external device. The image forming apparatus 1 can also supply image data to be supplied to the image forming unit 20 to an external device such as a computer or a printer as necessary.

[2: Operation]
Next, processing performed by the image forming apparatus 1 having the above-described configuration will be described. In the image forming apparatus 1 of the present embodiment, the image reading unit 10 reads an object to be imaged to generate an image signal, and the image processing unit 50 performs image processing on the image signal to generate image data. The image forming unit 20 forms a toner image corresponding to the image data, and forms the image by transferring and fixing the toner image on a recording sheet. Hereinafter, each of the process in which the image reading unit 10 reads an image and generates image data and the image forming process by the image forming unit 20 will be described.

[2-1: Image data generation processing]
As already described, the image reading unit 10 performs two scanning operations and outputs different image signals to each. There are two types of image signals output at this time: diffusely reflected light (45 ° incident, 0 ° reflected) due to light from the light source 111 and regular reflected light (45 ° incident, 45 ° reflected) due to light from the light source 111. This is an image signal based on the reflected light. Among these, the image signal based on diffuse reflection light is an image signal for detecting color information of the object to be imaged, and the image signal based on regular reflection light is an image signal for detecting gloss information of the object to be imaged. . Therefore, in the following, an image signal based on diffusely reflected light is called a “color signal”, and an image signal based on regular reflected light is called a “gloss signal”.

Next, a scanning operation for obtaining these image signals will be described with reference to FIGS. 1 and 3 as appropriate. The order in which the two scanning operations are performed is not particularly limited, but here, the order of the color signal and the gloss signal will be described.
First, when outputting a color signal, the light source 111 irradiates the object to be imaged O with light. The rotating reflector 115 is adjusted to the position shown in FIG. 3 so as to prevent the reading of the diffuse reflected light _Ldr while preventing the regular reflected light L _sr from traveling. When the full-rate carriage 110 moves in the direction of arrow C in FIG. 1 in this state, light from the light source 111 is irradiated over the entire surface of the object to be imaged O, and the diffuse reflected light of the entire object to be imaged O is read by the line sensor 140. It is done. As a result, a color signal is generated and output to the image processing unit 50. The image processing unit 50 temporarily stores this color signal in the image memory.

Next, when obtaining the gloss signal, first, the rotating reflector 115 rotates and moves to a position indicated by 115 'in FIG. Thus the diffuse reflection light L _dr is absorbed by the light trap 115t. Thereafter, the light source 111 irradiates the object to be imaged O with light. By doing so, the light read by the line sensor 140 becomes specularly reflected light from the object to be imaged O. Therefore, when the full-rate carriage 110 moves in this state in the direction of arrow C in FIG. 1, the specularly reflected light of the entire object to be imaged O is read by the line sensor 140, and a gloss signal is generated. This gloss signal is also output to the image processing unit 50 and temporarily stored.

In this way, two types of image signals, color signals and gloss signals, are generated. These image signals are all output in three colors of R, G, and B. That is, the image reading unit 10 generates a total of six types of image signals and outputs them to the image processing unit 50.
Next, processing performed by the image processing unit 50 on the image signal generated as described above will be described.

  The image processing unit 50 generates image data based on the input image signal. Specifically, using the color signal among the image signals, the color signal is converted into a format in which the image forming unit 20 can form a toner image. When generating image data, the image processing unit 50 according to the present embodiment detects the gloss level of each pixel in the image area and performs processing for generating metallic information based on the gloss level. Hereinafter, these processes will be described.

  Note that image signals used in the image processing described below are subjected to basic image processing such as AD conversion, shading correction, and gamma conversion in advance. At this time, the R, G, B 3 color image signals are subjected to color system conversion processing and converted to CIELAB color system L *, a *, b * image signals. Here, L * is the metric brightness and represents the brightness of the color. Further, a * and b * are chromaticity coordinates, and represent color attributes based on hue and saturation.

  FIG. 7 is a flowchart showing image data generation processing performed by the image processing unit 50. Describing along the drawing, first, the image processing unit 50 generates image data representing an object to be imaged using a color signal (step Sa1). Subsequently, the image processing unit 50 calculates the glossiness for each pixel representing the image signal using the gloss signal (step Sa2). Specifically, the image processing unit 50 compares the metric brightness of the gloss signal with the gloss level determination table TBL stored in the storage unit 40, and sets the gloss level corresponding to the metric brightness as the gloss level of the pixel.

  The image processing unit 50 performs such processing for all the pixels represented by the gloss signal. That is, if there is a pixel for which the above-described processing has not yet been performed (step Sa3; NO), the image processing unit 50 repeats the process of calculating the gloss level for the pixel (step Sa2).

  Then, after calculating the glossiness of all the pixels (step Sa3; YES), the image processing unit 50 identifies a region that is highly glossy from the image regions represented by the image signal (step Sa4). The value of the glossiness level is given to each pixel by the processing of step Sa2, but it is arbitrary from which glossiness level the high glossiness is assumed. Here, a pixel having a gloss level of “8” or higher is assumed to be highly glossy. The image area identified as having high gloss in this way is hereinafter referred to as a “metallic area”.

When the metallic area is specified, the image processing unit 50 generates metallic information based on the metallic area (step Sa5). The metallic information is information indicating which image area of the image data is highly glossy, and is given as layer information to the image data, for example.
FIG. 8 shows an example of metallic information. This figure is an example when a mobile phone is imaged as an object to be imaged, and shows image data G and layer information L. In this mobile phone, the body (area a1) and the operation buttons (area a2) are painted metallic. In the layer information L in this case, an area a1 indicated by hatching and a filled area a2 indicate metallic areas. Here, the gloss areas may represent different gloss levels, for example, the gloss level of the area a2 is “8” and the gloss level of the area a1 is “9”.

  Then, the image processing unit 50 compares each region represented by the image data with the metallic information, and specifies a portion that becomes a metallic region in the image data (step Sa6). Referring to FIG. 8 as an example, the image processing unit 50 sequentially compares the image data G and the layer information L in predetermined area units (for example, pixel units), and which area of the image data G is an area in the layer information L It is specified whether it corresponds to a1 and area a2.

When the metallic area in the image data is specified, the image processing unit 50 specifies the color of the metallic area and determines whether the metallic area is gold or silver (step Sa7). This determination is performed, for example, in such a manner that if the chromaticity in the determination target region is close to yellow, the color is gold, and in other cases, the color is silver.
Note that when there is more metallic color toner that can be used by the image forming apparatus 1, it is not limited to the determination of whether it is gold or silver, but a detailed determination may be made according to the number of colors.

  After specifying the color of the metallic area, the image processing unit 50 subsequently performs color conversion processing for expressing the image data with toner (step Sa8). Specifically, the image processing unit 50 specifies a color for each pixel in the image area represented by the image data, and converts the color into a format that allows the image forming unit 20 to form a toner image. That is, here, the process of describing each part of the image area in Y, M, C (, K) is performed.

The image processing unit 50 performs screen processing on the image data (step Sa9). Specifically, the image processing unit 50 specifies the blending ratio and area ratio of each color toner for each part of the image region, and specifies the halftone dot shape. At this time, the image processing unit 50 specifies various conditions for forming Y, M, C, and K toners for the entire image data, and then applies Au or Ag toner to the metallic region in the image data. Identify the conditions for forming.
When the above processing is completed, the image processing unit 50 outputs the image data to the image forming unit 20 (step Sa10).

  As described above, the image data generation process is performed. By performing this process, it is possible to add metallic information to the image data. By performing the image forming process using the metallic information, the image forming apparatus 1 can reflect the gloss on the metallic region of the object to be imaged.

[2-2: Image formation processing]
Here, a process in which the image forming unit 20 forms an image on a recording sheet based on the image data generated by the image processing unit 50 will be described.
FIG. 9 is a flowchart illustrating image forming processing performed by the image forming unit 20. Describing along the drawing, first, when certain image data is input, the image forming unit 20 uniformly charges the photosensitive drum 211 with a predetermined charging voltage (step Sb1). Subsequently, the image forming unit 20 determines whether or not metallic information is added to the input image data (step Sb2). That is, the image forming unit 20 determines whether or not a metallic area exists for the image data.

  If the metallic area exists (step Sb2; YES), the image forming unit 20 creates a toner image using Au or Ag toner based on the metallic information (step Sb3). Here, “image formation” includes each process in which an electrostatic latent image is exposed, toner is attached to the electrostatic latent image, and primary transfer is performed on the intermediate transfer belt 220. In this case, if the level is divided into the metallic area indicated by the metallic information, the image forming unit 20 adjusts the exposure amount according to the level and changes the amount of toner. On the other hand, if the metallic region does not exist (step Sb2; NO), the image forming unit 20 skips the above-described processing for forming the Au or Ag toner image.

Subsequently, the image forming unit 20 sequentially forms Y, M, C, and K toner images in the same manner as in the case of the above-described Au or Ag toner (step Sb4). When a toner image of a necessary color is formed by the above processing, the image forming unit 20 conveys the toner image on the intermediate transfer belt 220 and performs secondary transfer onto the recording paper at the position of the secondary transfer roll 240 (step) Sb5). Then, the image forming unit 20 conveys the recording paper, fixes the toner image transferred to the recording paper in the fixing mechanism 270 (step Sb6), and discharges the recording paper (step Sb7).
By performing the operation described above, the image forming apparatus 1 according to the present embodiment can form an image in which the metallic region of the object to be captured is well reproduced.

[3: Modification]
Although one embodiment of the present invention has been described above, the present invention is not limited to such an aspect, and various modifications can be made in the implementation. In the following, modifications applicable to the present invention will be exemplified.

First, various configurations of image forming means such as a mirror are conceivable. An example is shown in FIGS.
The full rate carriage 310 in FIG. 10 is an example in which a liquid crystal shutter is provided. In the figure, a full rate carriage 310 includes a light source 311, mirrors 312, 313, 314, 315, a half mirror 316, and a liquid crystal shutter 317. The liquid crystal shutter 317 is a device that can vary the transmittance of light traveling inside by applying a voltage. Here, the region 317a where the diffuse reflected light L _dr travels and the regular reflected light L _sr are transmitted. It is possible to change the transmittance of the traveling region 317b independently. The half mirror 316 reflects the diffusely reflected light L _dr from the mirror 313 while transmitting the regular reflected light L _sr from the mirror 315. When reading the diffusely reflected light _Ldr using the full rate carriage 310, the transmittance of the region 317a is increased to nearly 100%, while the transmittance of the region 317b is decreased to nearly 0%. When the regular reflection light L _sr is read using the full rate carriage 310, the transmittance of the region 317a is reduced to near 0%, while the transmittance of the region 317b is increased to near 100%. Even if such a configuration is used, both the regular reflection light L _sr and the diffuse reflection light L _dr can be read by the full rate carriage. When this configuration is used, it is possible to adjust the light amount of the _regularly reflected light L _sr to be read, so that even a highly glossy object to be imaged that exceeds the reading limit of the line sensor is satisfactory. Can be read.

Further, the full rate carriage 410 in FIG. 11 is an example in which a prism mirror is provided. In the figure, the full rate carriage 410 includes a light source 411, a rotating light trap 412, and a prism mirror 413. The prism mirror 413 is formed by coating a mirror layer, a half mirror layer, an antireflection layer, or the like on the surface of a plurality of prisms formed of a low refractive index / low dispersion glass material such as BK7 manufactured by SCHOTT. It is a polygonal column obtained by bonding with an optical adhesive having substantially the same refractive index. The cross section of the prism mirror 413 is a heptagon with A, B, C, D, E, F, and G as vertices, and an aluminum thin film having a mirror function is vacuum-deposited on the surfaces AB, CD, and DE. Further, the surface CF forms a half mirror, and an antireflection layer similar to the light trap 115t is provided in a portion corresponding to 413t in the drawing of the surface DE. The turning light trap 412 is provided with an antireflection layer similar to the light trap 115t on both surfaces thereof, and is turned around 412a by a driving means (not shown). The rotating light trap 412 absorbs the diffuse reflected light _Ldr from the object to be imaged O when it is at a position along the surface EF of the prism mirror 413, and the object to be imaged O when it is at a position along the surface DE of the prism mirror 413. The specularly reflected light L _{sr from} is absorbed. Even if such a configuration is used, both the regular reflection light L _sr and the diffuse reflection light L _dr can be read by the full rate carriage.
Of course, in addition to the above-described example, various modifications can be applied by increasing the number of reflections of reflected light.

In any of the cases described above, it is desirable that the distances from the object to be imaged to the imaging means, that is, the optical path lengths, of the regular reflection light L _sr and the diffuse reflection light L _dr are equal to each other. In this way, it is not necessary to adjust the focal length each time the scanning operation is performed, and the processing efficiency can be improved. Furthermore, it is desirable that the number of reflections of the regular reflection light L _sr and the diffuse reflection light L _{dr by} the mirror is both odd or even. In this way, it is possible to make the image directions coincide when each reflected light forms an image.

  Subsequently, a modification of the line sensor will be described. In the above-described embodiment, the line sensor 140 is described as a multi-line CCD image sensor including an on-chip color filter. However, the present invention is not limited to such a configuration. For example, the image pickup unit may be a one-line image sensor and may include a slide type or rotary type color filter. With such a configuration, the line sensor can be configured at a lower cost.

  In the above-described embodiment, the glossiness is determined by the CIELAB color system. However, the present invention is not limited to such a mode, and the glossiness is determined while the image signal remains in the RGB color system. It is also possible to do. In this case, for the determination of the metallic color, for example, a weighted average of the color values of R, G, and B colors can be used.

Subsequently, a modification of the image forming unit will be described. In the above-described embodiment, the rotary developing mechanism 210a including the four developing units 214, 215, 216, and 217 and the developing mechanisms 210b, 210c, and 210d including the single color developing devices 214b, 214c, and 214d are given. However, other configurations may be used. For example, a tandem developing device in which all seven colors are arranged in series may be used, or a plurality of rotary developing mechanisms may be provided. At this time, of course, the number of toner colors may be increased or decreased.
Further, instead of the intermediate transfer belt, a paper conveyance belt may be provided, and the transfer from the photosensitive drum to the recording paper may be performed directly without performing the transfer to the intermediate transfer body (intermediate transfer belt).

  In the above-described embodiment, it has been described that the toner image of Au or Ag is formed in the metallic region. However, in addition to this processing, processing that increases the surface of the metallic region with, for example, transparent toner may be performed. In this way, it is possible to increase the glossiness of the metallic region, and a more preferable image can be obtained.

  In the above-described embodiment, the case where the present invention is applied to an image forming apparatus has been described. However, the present invention is not limited to such an embodiment. For example, according to the imaging apparatus (scanner) having a configuration corresponding to the image reading unit and the image processing unit of the present embodiment, it is possible to output an image signal that can identify the above-described metallic region. Even if no part is provided, certain effects can be achieved. That is, the present invention is also specified as such an imaging apparatus.

1 is a diagram illustrating an apparatus configuration of an image forming apparatus according to an embodiment of the present invention. It is the figure which showed notionally the reflection state of the light from a to-be-photographed object. It is the figure which showed the structure of the full rate carriage in the same embodiment in detail. It is the figure which showed the structure of the image development mechanism in the same embodiment in detail. 2 is a block diagram functionally showing the configuration of the image forming apparatus according to the embodiment. FIG. It is the figure which showed the data structure of the glossiness determination table in the embodiment. 3 is a flowchart illustrating image data generation processing performed by an image processing unit in the embodiment. It is the figure which showed an example of metallic information. 3 is a flowchart illustrating image forming processing performed by an image forming unit in the embodiment. It is the figure which showed the modification of the full rate carriage. It is the figure which showed the modification of the full rate carriage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 10 ... Image reading part, 110 ... Full-rate carriage, 120 ... Half-rate carriage, 130 ... Imaging lens, 140 ... Line sensor, 150 ... Platen glass, 160 ... Platen cover, 20 ... Image forming part, 210, 210a, 210b, 210c, 210d ... developing mechanism, 220 ... intermediate transfer belt, 230 ... primary transfer roll, 240 ... secondary transfer roll, 250 ... backup roll, 260 ... feed mechanism, 270 ... fixing mechanism, 30 ... Control unit, 40 ... storage unit, 50 ... image processing unit, 60 ... operation unit, 70 ... data input / output unit.

Claims (8)

Irradiating means for irradiating the imaged object with light;
First imaging means for forming an image of diffusely reflected light from the imaging object that is generated when the irradiation means irradiates light;
Second imaging means for imaging regular reflection light from the imaged object generated by the irradiation means irradiating light;
Imaging means for receiving light imaged by the first or second imaging means and generating an image signal corresponding to the light;
Image data generating means for generating image data indicating the object to be picked up from a first image signal generated by the imaging means in response to the diffuse reflected light;
Metallic information generating means for generating metallic information indicating a glossy region on the object to be picked up from a second image signal generated by the imaging means in response to the regular reflection light;
An imaging apparatus comprising: output means for adding the metallic information generated by the metallic information generating means to the image data generated by the image data generating means and outputting the image data. The metallic information generation means calculates a glossiness for each pixel represented by the second image signal, and generates the metallic information in an area on the imaged object that exceeds a determined glossiness. Imaging device. The first imaging means forms an image of diffuse reflection light having a reflection angle from the imaging object of -5 ° to 5 °,
The imaging apparatus according to claim 1, wherein the second imaging means forms an image of specularly reflected light having a reflection angle of 40 ° to 50 ° from the object to be imaged. Irradiating means for irradiating the imaged object with light;
First imaging means for forming an image of diffusely reflected light from the imaging object that is generated when the irradiation means irradiates light;
Second imaging means for imaging regular reflection light from the imaged object generated by the irradiation means irradiating light;
Imaging means for receiving light imaged by the first or second imaging means and generating an image signal corresponding to the light;
Image data generating means for generating image data indicating the object to be picked up from a first image signal generated by the imaging means in response to the diffuse reflected light;
Metallic information generating means for generating metallic information indicating a glossy region on the object to be picked up from a second image signal generated by the imaging means in response to the regular reflection light;
Supplying means for supplying the image data generated by adding the metallic information generated by the metallic information generating means to the image data generated by the image data generating means;
An image forming apparatus comprising: an image forming unit that forms a toner image on a recording material based on the image data supplied by the supply unit. The image forming apparatus according to claim 4, wherein the image forming unit forms a toner image with metallic toner in an area indicated by the metallic information. The image forming unit includes:
A toner image can be formed with at least two or more metallic toners;
The image forming apparatus according to claim 5, wherein a toner color of a toner image formed in an area indicated by the metallic information is determined based on color information of an area of the image data corresponding to the area indicated by the metallic information. The image forming apparatus according to claim 4, wherein the image forming unit forms a toner image using a transparent toner in an area indicated by the metallic information. Irradiating the imaged object with light and generating a first image signal corresponding to the diffusely reflected light; and
Irradiating the imaged object with light and generating a second image signal corresponding to the specularly reflected light;
Generating image data indicating the object to be imaged from the first image signal;
Generating metallic information indicating a glossy region on the object to be imaged from the second image signal;
A method for reading an object to be imaged comprising: adding the metallic information to the image data and outputting the image data.

Images