Printed matter, printed matter manufacturing method, and image forming apparatus

A printed matter includes a recording medium; a chromatic color layer formed, with a chromatic colorant, on the recording medium; a plurality of first regions formed with a transparent material and arranged at intervals on the chromatic color layer; and a plurality of second regions each of which is disposed between adjacent two of the plurality of first region. A first unit material amount calculated by dividing an amount of the transparent material in the plurality of first regions with an area of the plurality of first regions is different from a second unit material amount calculated by dividing an amount of the transparent material in the plurality of second regions with an area of the plurality of second regions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application Nos. 2017-236288, filed on Dec. 8, 2017, and 2018-221135, file on Nov. 27, 2018, in the Japan Patent Office, the entire disclosure of each of which is hereby incorporated by reference herein.

BACKGROUND

Technical Field

The present disclosure relates to a printed matter, a method for manufacturing a printed matter, and an image forming apparatus.

Description of the Related Art

Attempts have been made to print metallic color patterns on recording media using an image forming apparatus employing, for example, an electrophotographic method or an inkjet method. For example, printing using a metallic color material for, such as, gold color in addition to color materials of four colors of cyan (C), magenta (M), yellow (Y), and black (K), which is also referred to as CMYK, has been tried. However, metallic luster attained with the metallic color material may be insufficient.

In order to attain metallic luster in a pseudo manner, attempts are also made to perform printing using a glossy transparent material. The transparent material is also referred to as “clear material”. The glossy transparent material enhances smoothness of the surface of the printed matter and enhances the gloss level of the printed matter. For example, a proposed approach involves referring to red, green, and blue (RGB) data of a target pixel and a color separation look-up table (LUT), acquiring CMYK values of the target pixel and a value of the glossy transparent material, and printing an image in which the hue of diffused light coincides with the hue of specularly reflected light.

SUMMARY

According to an embodiment of the present disclosure, a printed matter includes a recording medium; a chromatic color layer formed, with a chromatic colorant, on the recording medium; a plurality of first regions formed with a transparent material and arranged at intervals on the chromatic color layer; and a plurality of second regions each of which is disposed between adjacent two of the plurality of first region. A first unit material amount calculated by dividing an amount of the transparent material in the plurality of first regions with an area of the plurality of first regions is different from a second unit material amount calculated by dividing an amount of the transparent material in the plurality of second regions with an area of the plurality of second regions.

According to another embodiment, an image forming apparatus includes a printer configured to form an image on a recording medium, and circuitry configured to acquire input data indicating an area and a color of a metallic luster area expressing metallic luster of a chromatic color on the recording medium, and generate print data from the input data, The print data includes chromatic color layer data representing data of a chromatic color layer formed with a chromatic colorant, and transparent material layer data representing data of a transparent material layer, The transparent material layer includes a plurality of first regions arranged at intervals and a plurality of second regions each of which is disposed between adjacent two of the plurality of first regions. The transparent material layer data indicates that a first unit material amount calculated by dividing an amount of the transparent material in the plurality of first regions with an area of the plurality of first regions is different from a second unit material amount calculated by dividing an amount of the transparent material in the plurality of second regions with an area of the plurality of second regions. The circuitry is further configured to form, with the printer, the chromatic color layer on the recording medium based on the chromatic color layer data; and form, with the printer, the transparent material layer on the chromatic color layer based on the transparent material layer data.

Another embodiment provides a printed matter manufacturing method. The method includes designating an area and a color of a metallic luster area expressing chromatic metallic luster on a recording medium and generating print data based on the area and the color designated. The print data includes chromatic color layer data representing data of a chromatic color layer formed with a chromatic colorant, and transparent material layer data representing data of a transparent material layer formed with a transparent material. The transparent material layer includes a plurality of first regions arranged at intervals and a plurality of second regions each of which is disposed between adjacent two of the plurality of first regions. The transparent material layer data indicates that a first unit material amount calculated by dividing an amount of the transparent material in the plurality of first regions with an area of the plurality of first regions is different from a second unit material amount calculated by dividing an amount of the transparent material in the plurality of second regions with an area of the plurality of second regions. The method further includes forming the chromatic color layer on the recording medium based on the chromatic color layer data, and forming the transparent material layer on the chromatic color layer based on the transparent material layer data.

DETAILED DESCRIPTION

As a result of intensive studies to express the texture of metal color, the inventor has found that chromatic color saturation is insufficient in an attempt of artificially expressing metallic luster of chromatic color using such a glossy transparent material. The inventor has also found that insufficient saturation is caused because specularly reflected light by a glossy transparent material layer is excessive and specularly reflected light by a chromatic material layer is insufficient. Further, according to the study of the inventor, when the amount per unit area of the transparent material (the amount of the transparent material divided by the area of the glossy transparent material layer) in the glossy transparent material layer is changed, excessive specular reflection by the glossy transparent material is suppressed, and the specularly reflected light by the chromatic material layer is strengthened, thereby remarkably improving the saturation.

Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views thereof, embodiments of this disclosure are described. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

In the following description, a clear toner (i.e., transparent toner) is used as an example of glossy transparent material, and a chromatic color toner is used as an example of chromatic colorant. However, embodiments according to the present disclosure are not limited to toner, but can adapt to configurations using ink or the like.

Embodiment 1 is described. Embodiment 1 relates to a printed matter.FIG. 1Ais a schematic plan view illustrating a configuration of a printed matter100according to Embodiment 1, andFIG. 1Bis a schematic cross-sectional view taken along a line I-I inFIG. 1A.

The printed matter100according to Embodiment 1 includes a recording medium110, a chromatic toner layer120(i.e., a chromatic material layer) on the recording medium110, and a clear toner layer130(i.e., a glossy transparent material layer) on the chromatic toner layer120. The chromatic toner layer120includes a plurality of first chromatic regions121and a plurality of second chromatic regions122. In the plan view ofFIG. 1A, the first chromatic region121and the second chromatic region122alternate, for example, at regular intervals. In the present embodiment, a saturation S2of the second chromatic region122is higher than a saturation S1of the first chromatic region121. The clear toner layer130(a transparent material layer) formed with clear toner (transparent material) includes a plurality of first regions131(transparent material regions) respectively overlapping with the first chromatic regions121in the cross-sectional view and a plurality of second regions132respectively overlapping with the second chromatic regions122in the cross-sectional view. The second regions132are disposed between adjacent two of the plurality of first regions131. In the present embodiment, the amount per unit area of clear toner of the second region132(the amount of clear toner of the second region132divided by the area of the second region132, hereinafter “amount t2”) is smaller than the amount per unit area of clear toner of the first region131(the amount of clear toner of the first region131divided by the area of the first region131, hereinafter “amount t1”).

The amount t1 (first unit material amount) can be calculated by either dividing the amount of clear toner (transparent material) in the plurality of the first regions131with the area of the plurality of first regions131or dividing the amount of clear toner in one of the plurality of the first regions131with the area of that first region131. Alternatively, the amount t1 can be calculated by dividing the amount of clear toner in a given area of the first region131with the given area. The same applies to the amount t2 (second unit material amount).

Preferably, the amount t2 per unit area of clear toner of the second region132is zero. In other words, inFIG. 1B, the clear toner layer130is formed on only the first chromatic regions121. The recording medium110is high-quality paper, gloss coated paper, matte coated paper, overhead projector (OHP) film, plastic film, or the like.

The chromatic toner layer120includes cyan (C) toner, magenta (M) toner, or yellow (Y) toner, or any combination thereof, and can further includes black (K) toner. The clear toner layer130is a layer of clear toner. Generally, the clear toner is a colorless toner without a colorant such as a pigment. However, the clear toner is not necessarily completely colorless as long as the total light transmittance is equal to or greater than 30%. The total light transmittance is measured in accordance with the total light transmittance test methods of Japanese Industrial Standards (JIS) K7361-1 and International Organization for Standardization (ISO) 13468-1. A sample (prepared toner) is irradiated with visible light emitted from a halogen lamp being a light source, to measure the total light transmittance.

Here, an effect of the printed matter100according to Embodiment 1 will be described.FIG. 2is a schematic diagram illustrating the effect of the printed matter100according to Embodiment 1. When the printed matter100is irradiated with light10, in the first region131, a part of the light10is reflected by the clear toner layer130(specularly reflected light31), and another part is reflected by the first chromatic region121under the first region131(specularly reflected light21). Yet another part is reflected by the second chromatic region122(specularly reflected light22). InFIGS. 1B and 2, since the amount t2 per unit area of the clear toner of the second region132is zero, the light10is not reflected by the second region132. Therefore, most of the light incident on the first region131is reflected by the first region131and the first chromatic region121although the manner of reflection depends on the incident angle. The specularly reflected light21from the first chromatic region121contains the chromatic color of the first chromatic region121. The specularly reflected light31from the first area131has the same brightness as the light10. Therefore, this configuration can obtain the specularly reflected light having the chromatic color of the first chromatic region121with a high gloss level. On the other hand, the light incident on the second region132is not reflected by the clear toner layer130. Most of the light incident on the second region132is reflected by the second chromatic region122although the manner of reflection depends on the incident angle. The specularly reflected light22from the second chromatic region122includes the chromatic color of the second chromatic region122. In the present embodiment, the saturation S2of the second chromatic region122is higher than the saturation S1of the first chromatic region121covered with the clear toner. Therefore, the specularly reflected light including the high-saturation chromatic color of the second chromatic region122can be obtained.

In this embodiment, the first chromatic region121and the second chromatic region122are adjacent to each other, and the first region131and the second region132are adjacent to each other, corresponding to the first chromatic region121and the second chromatic region122. Accordingly, in human vision, specularly reflected light40reflected from the printed matter100attains both of high gloss and high saturation.

With such an effect of the printed matter100, a high saturation can be obtained while obtaining high gloss, thereby satisfactory expressing the texture of the metallic color in a pseudo manner.

In the present embodiment, the second region132is a region where the amount t2 per unit area of the clear toner is zero. Alternatively, when the amount t2 per unit area of clear toner of the second region132is smaller than the amount t1 per unit area of clear toner of the first region131, the amount t2 is not necessarily zero. For example, the amount t2 per unit area of the second region132can be equal to or smaller than 10% of the amount t1 per unit area of the first region131. Even when the amount t2 of the second region132is not zero, the reflection by the second region132is weaker than the reflection by the first region131, and the reflection by the second chromatic region122is stronger than the reflection by the first chromatic region121. Accordingly, high saturation can be obtained.

In the present embodiment, the saturation S2of the second chromatic region122is higher than the saturation S1of the first chromatic region121. Alternatively, the saturation S2can be equal to the saturation S1. Even when the saturations S1and S2are equivalent, high saturation can be obtained since the reflection by the second chromatic region122is stronger than the reflection by the first chromatic region121.

Preferably, the first region131and the second region132are arranged at regular intervals to make color unevenness less perceptible to human eyes.

The area of the first region131is preferably larger than the area of the second region132to enhance the gloss level, which is one feature of metallic luster. Although not particularly limited, the area ratio between the first region131and the second region132is, for example, 2:1. The area ratio can be 3:1, 3:2, 1:1, or the like.

Although not particularly limited, the resolution of the printed matter100is preferably equal to or greater than 300 dots per inch (dpi), and more preferably equal to or greater than 600 dpi. Such resolution can make specularly reflected light from each region less distinguishable in human perception. According to an aspect of the present disclosure, a printed matter includes a recording medium, a chromatic material layer on the recording medium, a glossy transparent material layer on the chromatic material layer. The transparent material layer includes a first region having a first colorant amount per unit area and a second region having a second colorant amount per unit area different from the first colorant amount. According to an aspect, a bottom of each of the plurality of recesses is defined by the chromatic material layer.

Next, Embodiment 2 is described. Embodiment 2 relates to a method for manufacturing a printed matter.FIG. 3is a schematic diagram illustrating a printed matter to be manufactured according to Embodiment 2.FIG. 4is a flowchart of a printed matter manufacturing method according to Embodiment 2.FIGS. 5A to 5Fare schematic diagrams illustrating the method for manufacturing the printed matter according to Embodiment 2 in the order of processes. For example, the method is executed by a processor of an image forming apparatus or a computer.

As illustrated inFIG. 3, the printed matter to be manufactured according to Embodiment 2 is a certificate200(e.g., certificate of commendation) printed on a recording medium250, and the certificate200includes a text area210and a peripheral area220around the text area210. In the peripheral area220, a decoration pattern including, for example, animals and plants, is drawn in gold color. Here, as an example, the printed matter is manufactured with a resolution of 600 dpi.FIGS. 5A to 5Fillustrate a rectangular range included in the decoration pattern in the peripheral area220, as an example of a metallic luster area.

In Embodiment 2, first, as illustrated inFIG. 5A, the area and the color of a metallic luster area expressing the metallic luster of chromatic color on the recording medium250are designated (S210). For example, as the metallic luster area, a decoration pattern area251(e.g., the metallic luster area) is designated and gold color is designated as the color thereof. To draw a pattern in gold, values of cyan, magenta, yellow, black, and transparent color are set, for example, as “C: 0%, M: 12%, Y: 57%, K: 6%, CL: 100%”, where CL represents “transparent color”.

Next, print data is generated (S220).

In preparation of print data, initially, of the chromatic color components (cyan, magenta, and yellow) of the gold color, yellow is selected (S221). Although a chromatic color component other than yellow can be selected, selecting yellow, which is closest to the glossy gold color among cyan, magenta, and yellow, is preferable. Since black is an achromatic color, black is excluded from the selection. As illustrated inFIG. 5B, a yellow pattern260matches the decoration pattern area251.

Next, the gradation value of the yellow pattern260is binarized (S222). Here, as illustrated inFIG. 5C, on the premise that the area ratio between a first portion261assigned with a yellow gradation value being 0% and a second portion262assigned with a yellow gradation value being 100% is 2:1, provisionally, the yellow gradation value is changed to 33%, and binarization processing is performed to generate a binarized pattern263of yellow. The yellow gradation value being 0% is an example first binarized value, and the yellow gradation value being 100% is an example second binarized value. Alternatively, the area ratio between the first portion261and the second portion262can be 3:1, 3:2, 1:1, or the like.

Next, as illustrated inFIG. 5D, the transparent (clear or CL) gradation value of a portion272(a second transparent portion) overlapping with the second portion262(yellow gradation value is 100%) is changed from 100% to 0%, and the transparent gradation value of a portion271(a first transparent portion) overlapping with the first portion261(yellow gradation value is 0%) is kept at 100%. Such operation generates clear toner layer data (transparent material layer data) in which a transparent gradation value of 100% is set in the portion271overlapping with the first portion261and a transparent gradation value of 0% is set in the portion272overlapping with the second portion262(S223).

Next, as illustrated inFIG. 5E, the yellow gradation value in the first portion261is changed from 0% to 36%. In a planar view, two thirds (⅔) of the chromatic toner layer120is made the first chromatic region121, and one third (⅓) of the chromatic toner layer120is made the second chromatic region122. This operation is to approximate the average of the yellow gradation values in the whole metallic luster area to the gradation value before binarization, while setting the yellow gradation value of the second chromatic region122at 100%. That is, if the binarized values are used as is, the average of the yellow gradation values in the entire metallic luster area is 33%. However, when the gradation value is changed to 36%, the average of the yellow gradation values can be about 57%. Such operation can generate chromatic toner layer data (chromatic material layer data) in which the average of the yellow gradation values in the entire metallic luster area is changed to be closer to the gradation value before binarization (S224). Only to make the average value close to the gradation value before binarization, alternatively, the gradation value of the second portion262can be changed without changing the gradation value of the first portion261. Yet alternatively, the gradation values of both the first portion261and the second portion262can be changed. However, in order to bring the average value closer to the gradation value before binarization while obtaining high saturation, preferably, the gradation value of only the first portion261, in which the gradation value is provisionally set to 0%, is changed.

In this manner, the print data is generated (S220). For the colors (cyan, magenta, and black) other than yellow selected in S221, the gradation value designated in S210is used as is. Therefore, in this print data, the gradation values of the first chromatic region121are expressed as “C: 0%, M: 12%, Y: 36%, and K: 6%”, and the gradation values of the second chromatic region122are expressed as “C: 0%, M: 12%, Y: 100%, and K: 6%”. Further, the gradation value of the first region131is expressed as “CL: 100%”, and the gradation value of the second region132is expressed as “CL: 0%”.

After generating the print data, using the image forming apparatus, printing is performed (S230). Specifically, a chromatic toner layer is formed on the recording medium250according to the print data (S231). Then, a clear toner layer is formed on the chromatic toner layer (S232). A pattern283printed on the recording medium250as the result of the above-described process includes, as illustrated inFIG. 5F, an area281in which the first chromatic region121overlaps the first region131and an area282in which the second chromatic region122overlaps the second region132.

In this way, a printed matter can be produced. The pattern283formed on the recording medium250can express the golden metallic luster in a pseudo manner.

Note that the binarized pattern is not limited to a pattern in which two types of regions are arranged in one direction but can be a pattern in which two types of regions are arranged in two directions orthogonal to each other. That is, the binarized pattern can be a grid pattern.

Hereinafter, a description is given of Embodiment 3 of the present disclosure. Embodiment 3 relates to an image forming apparatus suitable for implementing the printed matter manufacturing method according to Embodiment 2.FIG. 6is a block diagram illustrating a hardware configuration of an image forming apparatus300according to Embodiment 3.

The image forming apparatus300according to Embodiment 3 includes, for example, a central processing unit (CPU)301, a random access memory (RAM)302, a read only memory (ROM)303, a memory304, a network interface (I/F)305, an operation unit306, a scanner307, a printer308, an image memory309, a wireless communication device310, and a bus311.

The CPU301is a processor that reads out programs and data stored in, for example, the ROM303and the memory304to the RAM302and executes processing to implement functions of the image forming apparatus300. The RAM302is a volatile memory to be used as a work area for the CPU301. The ROM303is a non-volatile memory that can hold the programs and the data even after power is turned off and back on.

The memory304is a mass storage, such as a hard disk drive (HDD) and a solid state drive (SSD), and stores, for example, an operating system (OS), an application program, and various types of data. The network interface I/F305is an interface that connects the image forming apparatus300to a network. The operation unit306is a display and input device, such as a touch panel, for displaying and inputting. The operation unit306doubles as an input device to accept an operation and input from a user and a display device such as a liquid crystal display (LCD).

The scanner307is a reading device that reads an image on a document and converts the read image into image data. The printer308is an image forming device that performs printing according to the image data. The image memory309is a memory used as a work area in image processing in reading, printing, copying, and the like of images.

The wireless communication device310is a communication device that communicates with a computer, a mobile phone, or the like by wireless communication such as a wireless local area network (LAN), a wireless personal area network (PAN), infrared communication, or acoustic communication. The bus311is connected to each of the above-described elements and transmits address signals, data signals, and various types of control signals.

Hereinafter, a description is given of a functional configuration of the image forming apparatus300. As described above, the CPU301reads out programs and data stored in the ROM303or the memory304to the RAM302and executes processing to implement functions of the image forming apparatus300.FIG. 7is a functional block diagram of the image forming apparatus300according to Embodiment 3. As illustrated inFIG. 7, the image forming apparatus300includes an acquisition unit351, a print data generation unit352, and a printing unit353.

The acquisition unit351acquires input data indicating the area and color of the metallic luster area expressing metallic luster of the chromatic color on the recording medium. The input data can be acquired via the network I/F305or the wireless communication device310. The image forming apparatus300can further include a slot for an external recording medium so that input data can be acquired from the external recording medium such as an integrated circuit (IC) card, a flexible disk, a compact disc (CD), a digital versatile disc (DVD), a secure digital (SD) memory card, a universal serial bus (USB) memory, or the like. The print data generation unit352generates print data using the image memory309or the like, as in S220. The printing unit353performs printing using the printer308or the like, as in S230.

When the input data is acquired by the acquisition unit351, the image forming apparatus300performs the same processing as the printed matter manufacturing method according to Embodiment 2, to produce a printed matter that expresses the metallic color texture in a pseudo manner.

The color of the metallic luster area is not limited to gold color but can be copper color, bronze color, or the like. For example, since the copper color is reddish, to express the copper color texture in a pseudo manner, the proportion of magenta in the base color is increased, and the chromatic color component whose gradation value is to be binarized is magenta. Depending on the color to be expressed, gradation values of two or more chromatic color components can be binarized.

In addition, the clear toner layer can contain three or more regions which are different in amount per unit area of clear toner, and the chromatic toner layer can include three or more regions different in saturation. In this case, preferably, the amount per unit area of clear toner in the clear toner layer is smaller in the region overlapping the region of the chromatic toner layer having a higher saturation, and similar to Embodiment 1, preferably, the amount per unit area of clear toner in the region overlapping with the highest saturation region is zero to expose the highest saturation region thereunder. Note that the amount per unit area of clear toner in the description above is the amount obtained by dividing the amount of clear toner of the corresponding region by the area of the corresponding region.

In these embodiments, a clear toner is used as a glossy transparent color material and a chromatic toner is used as a chromatic color material, but the color material according to the present disclosure is not limited to toner. For example, aspects of the present disclosure can adapt to configurations in which the color material is ink or the like.