JP6119115B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  In recent years, in order to bring the image quality of electrophotographic technology closer to offset printing, in addition to conventional colored toners such as Y, M, C, K (yellow, magenta, cyan, black), transparent toner (hereinafter referred to as glossy) The toner having no color such as clear toner) has been used.

  As one of the methods using clear toner, a clear toner overlay method is known. First, clear toner form data for instructing a clear toner application position is transmitted and registered in advance from a printer driver such as a personal computer to the image forming apparatus, and the pre-registered clear toner form data is specified at the time of job transmission. This is a method of forming an image with clear toner by combining image data of a job with designated clear toner form data in an image forming apparatus.

In such a clear toner overlay technique, a technique for an operator to preview an actual application position of the clear toner has been proposed.
For example, Patent Document 1 describes a print control apparatus that assigns specific colors to a clear toner application position on which clear toner is placed and a portion on which clear toner is not placed, and displays a preview superimposed on a colored image of a document. ing. In the printing apparatus, even in an area designated as the clear toner application position, the clear toner may not be applied in an area where the density of the colored toner is equal to or less than a threshold value.

  Patent Document 2 describes an image forming apparatus that displays a clear toner image area in a highlighted manner as compared with a colored toner image area.

JP 2010-33419 A JP2011-59445A

  Here, with reference to FIGS. 13A to 13C, an example of the preview display according to the technique of Patent Document 1 in the case where the clear toner is placed only on the character area of the document image will be described. FIG. 13A is a diagram illustrating an image based on input document image data (color toner image data). FIG. 13B shows the clear toner application position indicated by the clear toner form data. The shaded area is the clear toner application position. FIG. 13C is a diagram showing an example of a preview image displayed using the technique of Patent Document 1 based on the image data of FIG. 13A and the clear toner form data of FIG. 13B. In FIG. 13C, the area where the clear toner is placed is shown in the first specific color (indicated by dots in FIG. 13C), and the area where the clear toner is not placed is shown in the second specific color (FIG. 13C). (Shown in white).

  The clear toner is originally colorless, but as shown in FIG. 13C, if a specific color is assigned as a marker indicating the application position, there is a problem that the image of the finished image becomes difficult to understand.

Also, referring to FIGS. 14A to 14D, an example of preview display by the techniques of Patent Document 1 and Patent Document 2 when an instruction to apply clear toner larger than the character area of the document image is given. explain.
FIG. 14A shows a document image based on the input document image data. FIG. 14B shows the clear toner application position indicated by the clear toner form data. The shaded area is the clear toner application position. The area of the toner application position is slightly larger than the character area of the image data shown in FIG. FIG. 14C is a diagram showing an example of a preview image displayed using the technique of Patent Document 1 based on the image data of FIG. 14A and the clear toner form data of FIG. 14B. In FIG. 14C, the area where the clear toner is placed is indicated by a first specific color (indicated by dots in FIG. 14C), and the area where the clear toner is not placed is shown in a second specific color (FIG. 14C). (Shown in white). FIG. 14D is a diagram showing an example of a preview display displayed using the technique of Patent Document 2 based on the image data in FIG. 14A and the clear toner form data in FIG. 14B. Here, the clear toner only region is indicated by black, and the clear toner and character overlapping region are indicated by dots.

As shown in FIG. 14C, in the preview display by the technique described in Patent Document 1, there is a problem that the image of the finished image is difficult to understand as described above. In addition, there is a problem that it is difficult to grasp the size relationship and positional relationship between the colored toner image region and the clear toner image region, and the user cannot grasp the fine overlapping state of the clear toner with respect to the colored toner image. For example, although the toner application position in this example is slightly larger than the character area of the colored toner, it is difficult to recognize it if only the image shown in FIG. 14C is displayed.
As shown in FIG. 14D, the preview display according to the technique described in Patent Document 2 shows the size relationship and the positional relationship between the colored toner image region and the clear toner image region, but there are subtle differences. If it is, it is still difficult to grasp. In addition, since the colored toner area and the clear toner area are superimposed with a color different from the finished image, there is a problem that it is difficult to grasp the image of the finished image.

  An object of the present invention is to enable a user to surely recognize a fine clear toner application position while imaging a finished image formed on a sheet.

In order to solve the above-mentioned problem, the invention described in claim 1
Based on the image data for color toner and the image data for clear toner, an image forming unit for forming an image composed of a color toner image and a clear toner image on a sheet, and a preview image of the image formed by the image forming unit An image forming apparatus including a display unit for displaying,
A timer unit that outputs an ON / OFF switching signal at a constant cycle;
An operation unit for a user to set a clear toner usage amount of the image forming unit with respect to a reference based on a clear toner usage amount based on clear toner form data indicating a clear toner application position in the color toner image data When,
The image data for the clear toner is generated based on the image data for the color toner, the clear toner form data, and the setting from the operation unit, and the color toner for the color toner is generated according to a switching signal from the timer unit. And a clear toner confirmation image in which the color of the pixel at the clear toner application position in the generated clear toner image data is displayed in a color different from the color of the pixel in the color toner image. And a control unit that alternately switches and displays the preview image on the display unit,
Is provided.

The invention according to claim 2 is the invention according to claim 1,
The control unit displays the color of the pixel at the clear toner application position in the generated clear toner image data in a color obtained by inverting the pixel value at the clear toner application position in the colored toner image. Display an image.

The invention according to claim 3 is the invention according to claim 1 or 2 ,
The timer unit increases or decreases the ON time or OFF time of the switching signal according to the difference between the clear toner usage amount based on the clear toner form data and the clear toner usage amount based on the clear toner image data.

The invention according to claim 4 is the invention according to any one of claims 1 to 3 ,
When the setting of the clear toner usage amount is changed by the operation unit, the control unit regenerates the image data for the clear toner based on the changed setting of the clear toner usage amount, and the color toner The color toner image based on the image data for use and the clear toner confirmation image based on the regenerated image data for clear toner are alternately switched and displayed as a preview image on the display unit.

The invention according to claim 5 is the invention according to any one of claims 1 to 4 ,
The operation unit can be set to increase the clear toner usage amount of the image forming unit on the basis of the clear toner usage amount based on the clear toner form data.

The invention according to claim 6 is the invention according to any one of claims 1 to 4 ,
The operation unit can be set to decrease the clear toner usage amount of the image forming unit based on the clear toner usage amount based on the clear toner form data.

  According to the present invention, it is possible for a user to reliably recognize a fine clear toner application position while imaging a finished image formed on a sheet.

2 is a block diagram illustrating a functional configuration of the image forming apparatus. FIG. FIG. 2 is a diagram illustrating a schematic configuration of an image forming unit in FIG. 1. 6 is a graph showing output image data and clear toner image data when the clear toner usage amount setting is standard. 6 is a graph showing output image data and clear toner image data when the clear toner usage amount setting is cost priority. 10 is a graph showing output image data and clear toner image data when the clear toner usage amount setting is gloss priority. 6 is a graph showing output image data and clear toner image data when the clear toner usage amount setting is color reproduction priority. 6 is a graph showing output image data and clear toner image data when the clear toner usage amount setting is paper type priority. It is a flowchart which shows the preview display process performed by the control part of FIG. It is a figure which shows the process for displaying a preview image on a display part. 6 is a timing chart showing switching of a switching signal output by a timer unit and display of a preview image. FIG. 10 is a diagram illustrating a preview display example when a character area of a color toner image matches a clear toner application position. FIG. 10 is a diagram illustrating a preview display example when a clear toner application position is slightly larger than a character area of a color toner image. FIG. 10 is a diagram for explaining a preview display according to the related art when a character area of a color toner image matches a clear toner application position. FIG. 10 is a diagram for explaining a preview display according to a conventional technique when a clear toner application position is slightly larger than a character area of a colored toner image.

  The configuration and operation of the image forming apparatus in this embodiment will be described in detail with reference to the drawings. In the present embodiment, a color image forming apparatus will be described as an example. However, the present invention is not limited to this, and the present invention can be realized by, for example, a monochrome image forming apparatus.

(Configuration of image forming apparatus 1)
FIG. 1 shows a functional block diagram of the image forming apparatus 1.
As shown in FIG. 1, the image forming apparatus 1 includes an image reading unit 101, an input image processing unit 102, an image memory unit 103, an output image processing unit 104, an image forming unit 105, an HDD 107, a communication unit 108, a control unit 110, The storage unit 111, the timer unit 112, the operation unit 113, and the display unit 114 are configured, and each unit is connected via the bus 106.

  The image reading unit 101 includes a light source, an optical system, an image sensor, and the like. An image reading unit 101 scans a document to read an image of the document, generates R, G, B (red, green, blue) digital image data from the obtained analog image signal, and inputs an image processing unit 102. Output to.

  The input image processing unit 102 performs image processing such as shading correction and MTF correction on the input image data and outputs the processed image data to the image memory unit 103.

  The image memory unit 103 is configured by a semiconductor memory or the like. The image memory unit 103 stores the image data input from the input image processing unit 102, reads out the stored image data, and outputs it to the output image processing unit 104 at the time of image formation. If the free space is equal to or less than a predetermined threshold, the image data is temporarily saved in the HDD 107, and the image data is read from the HDD 107 and output to the output image processing unit 104 when necessary.

  The output image processing unit 104 converts the image data for three colors R, G, and B input from the image memory unit 103 into image data for four colors Y, M, C, and K (yellow, magenta, cyan, and black). The image data for clear toner created by the control unit 110 is output to the dedicated interface of the image forming unit 105. Note that color toner image data such as R, G, B, Y, M, C, and K is referred to as color toner image data. The clear toner image data is referred to as clear toner image data.

The image forming unit 105 forms an image on a sheet by electrophotography based on the color toner image data for four colors Y, M, C, and K and the clear toner image data.
The image forming unit 105 includes a color image forming unit that forms an image using four color toners of yellow, magenta, cyan, and black, and a transparent image forming unit that forms an image using a clear toner. have. The clear toner is a toner for adjusting the glossiness of an image and contains at least a binder resin. The clear toner is preferably colorless and transparent, but also includes a toner whose transparency is slightly lowered due to the components contained therein.

FIG. 2 shows a schematic configuration of the image forming unit 105.
As shown in FIG. 2, the image forming unit 105 includes exposure units 41CLR, 41Y, 41M, 41C, and 41K, developing units 42CLR, 42Y, 42M, 42C, and 42K, and photosensitive drums 43CLR, 43Y, 43M, and 43C. 43K, charging units 44CLR, 44Y, 44M, 44C, 44K, cleaning units 45CLR, 45Y, 45M, 45C, 45K, primary transfer rollers 46CLR, 46Y, 46M, 46C, 46K as transfer members, and intermediate transfer members As an intermediate transfer belt 47, a cleaning unit 48, a secondary transfer roller 49, a paper feeding unit 403, a conveying unit 404, and a fixing unit 405. The symbols CLR, Y, M, C, and K of the respective parts represent the toner colors handled in the respective parts, and represent transparent, yellow, magenta, cyan, and black, respectively.

The exposure units 41CLR, 41Y, 41M, 41C, 41K are LDs (Laser Diodes).
And the like, a polygon mirror, a plurality of lenses, and the like. The exposure units 41CLR, 41Y, 41M, 41C, and 41K scan and expose the surfaces of the photosensitive drums 43CLR, 43Y, 43M, 43C, and 43K with a laser beam based on the image data sent from the output image processing unit 104. By this laser beam scanning exposure, latent images are formed on the photosensitive drums 43CLR, 43Y, 43M, 43C, and 43K charged by the charging units 44CLR, 44Y, 44M, 44C, and 44K, that is, images are written.

  The latent images formed on the photoconductive drums 43CLR, 43Y, 43M, 43C, and 43K are visualized by attaching the toners of the respective color components by the corresponding developing units 42CLR, 42Y, 42M, 42C, and 42K. A toner image of each color component is formed on each photosensitive drum 43CLR, 43Y, 43M, 43C, 43K.

  The toner images formed and carried on the photosensitive drums 43CLR, 43Y, 43M, 43C, and 43K are intermediated by primary transfer rollers 46CLR, 46Y, 46M, 46C, and 46K to which a constant voltage is applied from a power source (not shown). The image is sequentially transferred to a predetermined position on the transfer belt 47 and is primarily transferred. Residual toner is removed from the surfaces of the photosensitive drums 43CLR, 43Y, 43M, 43C, and 43K after the transfer of the toner image by the cleaning units 45CLR, 45Y, 45M, 45C, and 45K.

The intermediate transfer belt 47 is a semiconductive endless belt that is suspended and supported rotatably by a plurality of rollers, and is driven to rotate as the rollers rotate.
The intermediate transfer belt 47 is pressure-bonded to the respective photosensitive drums 43CLR, 43Y, 43M, 43C, and 43K by the primary transfer rollers 46CLR, 46Y, 46M, 46C, and 46K. A transfer current corresponding to the applied voltage flows through each of the primary transfer rollers 46CLR, 46Y, 46M, 46C, and 46K. As a result, the toner images developed on the surfaces of the photosensitive drums 43CLR, 43Y, 43M, 43C, and 43K are sequentially transferred to the intermediate transfer belt 47 (primary) by the primary transfer rollers 46CLR, 46Y, 46M, 46C, and 46K, respectively. Transferred).
On the other hand, in the paper feeding unit 403, the type of paper instructed by the control unit 110 is fed and conveyed to the transfer position by the secondary transfer roller 49 by each unit of the conveyance unit 404. The toner image of the color image is transferred (secondary transfer) to the conveyed paper by the secondary transfer roller 49. After the transfer, the sheet is conveyed to the fixing unit 405, and the toner image transferred to the sheet is thermally fixed. Residual toner on the intermediate transfer belt 47 is removed by a belt cleaning unit 48.

Returning to FIG. 1, the HDD (Hard Disk Drive) 107 includes digital image data read by the image reading unit 101, color toner image data developed by the control unit 110, clear toner form data corresponding thereto, and a control unit. The clear toner image data generated in 110 and attribute data related thereto are stored in association with each job.
The communication unit 108 is connected to an external PC (Personal Computer) 109 via a LAN (Local Area Network) such as Ethernet (registered trademark), and transmits and receives various data.

The control unit 110 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The CPU of the control unit 110 reads out system programs and various processing programs stored in the ROM, expands them in the RAM, executes various processes according to the expanded programs, and centrally controls the operations of the respective units of the image forming apparatus 1.
For example, the control unit 110 converts image data (color toner image data) of a job input by the communication unit 108 from a page description language format such as a PDL (Page Description Page) format or a Tiff format to an image forming unit such as a bitmap. Raster image processing (RIP) processing that expands to an image format usable in 105 is performed.
The control unit 110 generates clear toner image data based on the clear toner form data input by the communication unit 108 and the color toner image data developed by the RIP process, and outputs the clear toner image data to the HDD 107.
Here, the clear toner form data is data input from the PC 109, and is binary data for instructing whether or not the clear toner is placed on each pixel of the color toner image data.
In addition, the control unit 110 executes a preview display process shown in FIG.

The storage unit 111 is configured by a semiconductor nonvolatile memory and stores various types of information. For example, the setting information input from the operation unit 113 is stored.
The timer unit 112 includes a time counting unit based on a crystal oscillator or the like, generates a switching signal that repeats ON / OFF at a constant period, and outputs the switching signal to the control unit 110.

The operation unit 113 includes various keys such as a numeric keypad, a start key for starting a job, and a preview display key for instructing a preview display. The operation unit 113 receives a key operation by the user and outputs an operation signal to the control unit 110. To do. Further, the operation unit 113 has a pressure-sensitive (resistance film pressure type) touch panel in which transparent electrodes are arranged in a grid pattern so as to cover the upper surface of the LCD of the display unit 114, and XY of a power point pressed with a finger or a touch pen The coordinates are detected by a voltage value, and the detected position signal is output to the control unit 110 as an operation signal. Note that the touch panel is not limited to a pressure-sensitive type, and may be another electrostatic type, an optical type, or the like.
The display unit 114 is configured by an LCD (Liquid Crystal Display) or the like, and displays various setting screens, job list screens, apparatus status displays, and image formations on the display screen in accordance with display signal instructions input from the control unit 110. A preview image for confirming in advance the finished image in the apparatus 1 is displayed.

In the present embodiment, the setting screen displayed by the display unit 114 includes a clear toner usage amount setting screen (not shown) for setting the clear toner usage amount by the operation unit 113.
The clear toner usage amount setting screen is provided with five operation buttons including a standard button, a cost priority button, a gloss priority button, a color reproduction priority button, and a paper type priority button. When any one of the operation buttons is pressed from the clear toner usage amount setting screen, the control unit 110 stores setting information corresponding to the pressed button in the storage unit 111.

Here, referring to FIG. 3 to FIG. 7, the color toner image data and the control unit 110 when the above-mentioned standard, cost priority, gloss priority, color reproduction priority, and paper type priority are set. The relationship of the clear toner image data will be described.
3 to 7, (a) is a diagram showing output image data (color toner image data + clear toner image data), and (b) is a diagram showing clear toner image data. The horizontal axis represents the pixel position, and the vertical axis represents the toner adhesion amount (toner usage amount).
In FIGS. 3 to 7, it is assumed that the clear toner form data instructs to apply the clear toner to a position where the colored toner exists.

  FIG. 3 is a diagram illustrating output image data and clear toner image data when a standard is set as the clear toner usage amount. The standard setting is a setting for applying a preset amount of clear toner to the clear toner application position instructed by the clear toner form data transmitted from the PC 109. The clear toner usage amount based on the clear toner form data is actually set. The amount of clear toner used by the image forming unit 105 is equal. For example, as shown in FIG. 3A, when the pixel positions where the colored toner is applied are X1, X3, and X5, as shown in FIG. 3B, clear toner is placed at the positions X1, X3, and X5. Applied.

FIG. 4 is a diagram illustrating output image data and clear toner image data when cost priority is set as the clear toner usage amount. In the cost priority setting, even if the clear toner application position is instructed by the clear toner form data transmitted from the PC 109, the clear toner is applied to the position where the toner adhesion amount based on the color toner image data is less than a predetermined threshold. Is set to not apply. If the amount of colored toner attached is less than a certain standard, the effect of clear toner will be reduced. Therefore, from the viewpoint of cost performance, the clear toner application to that part is cut, and the purpose is to reduce the amount of clear toner used. Yes.
For example, as shown in FIG. 4A, when the color toner adhesion amount at X1 is smaller than the threshold among the pixel positions X1, X3, and X5 to which the color toner is applied, as shown in FIG. 4B. Clear toner is not applied to the position X1.

FIG. 5 is a diagram illustrating output image data and clear toner image data when gloss priority is set as the clear toner usage amount. The gloss priority setting is a setting in which clear toner is applied to a position where there is no clear toner application instruction so that the difference in the total adhesion amount between the color toner and the clear toner is reduced between adjacent pixels. This is because when the difference in the toner adhesion amount between adjacent pixels is reduced, the smoothness of the image formed on the paper is increased and the glossiness is improved. In the case of the gloss priority setting, the clear toner usage amount is equal to or increased when the instruction according to the clear toner form data is followed.
For example, as shown in FIG. 5A, when the pixel positions to which the colored toner is applied are X1, X3, and X5, as shown in FIG. In addition to X3 and X5, clear toner is also applied to X0, X2, X4, and X6 for which clear toner application is not instructed.

FIG. 6 is a diagram illustrating output image data and clear toner image data when color reproduction priority is set as the clear toner usage amount. Even if the color reproduction priority setting is the clear toner application position indicated by the clear toner form data transmitted from the PC 109, the color toner and clear toner determined based on the color toner image data and the clear toner form data are used. When the total adhesion amount exceeds the maximum toner adhesion amount of the image forming unit 105, the clear toner is not applied to the position. The maximum toner adhesion amount is set so that an amount of toner exceeding the limit of the fixing performance in the image forming unit 105 is not adhered, and the total adhesion amount of the colored toner and the clear toner is the maximum toner adhesion amount. This is because the clear toner is not applied when the amount is exceeded, so that the color reproduction of the color toner image data is not affected. In the case of the color reproduction priority setting, the clear toner usage amount is equal to or decreased as in the case of following the instruction by the clear toner form data.
For example, as shown in FIG. 6A, the pixel positions to which the colored toner is applied are X1, X3, and X5, and when the clear toner is superimposed on the colored toner of X5, the total toner adhesion amount exceeds the maximum toner adhesion amount. In this case, as shown in FIG. 6B, the clear toner is not applied to the position X5.

FIG. 7 is a diagram illustrating output image data and clear toner image data when paper type priority is set as the clear toner usage amount. The paper type priority setting is a setting in which clear toner is applied even if there is no clear toner application instruction for pixels near the color toner. This is because a paper type having low smoothness, such as embossed paper, is improved in appearance when a clear toner is applied to improve the smoothness. In the case of the paper type priority setting, the clear toner usage amount is equal to or increased when the clear toner form data is followed.
For example, as shown in FIG. 7A, when the pixel positions to which the colored toner is applied are X1, X3, and X5, as shown in FIG. 7B, the clear toner application is instructed X1, In addition to X3 and X5, clear toner is also applied to X0, X2, X4, and X6 for which toner application is not instructed.

(Operation of Image Forming Apparatus 1)
Next, the operation of the image forming apparatus 1 will be described.
FIG. 8 shows a flowchart of the preview display process. The preview display process is executed by the control unit 110 when a preview display target job is selected by the operation unit 113 and a preview display is instructed.

  First, it is determined whether or not the clear toner image data for the selected job has been generated (step S1). If it is determined that the clear toner image data for the selected job has already been generated (step S1; YES), the process proceeds to step S3. If it is determined that clear toner image data for the selected job has not been created (step S1; NO), clear toner image data is generated (step S2), and the process proceeds to step S3.

  In step S2, first, the clear toner usage amount setting information in the storage unit 111 is referred to, and the color toner image data of the target job input from the PC 109 via the communication unit 108 and developed by the RIP process, and the communication unit Based on the clear toner form data input from the PC 109 via 108, clear toner image data corresponding to the clear toner usage amount setting is generated.

  For example, when the clear toner usage amount setting is standard, the clear toner image data is generated so that a predetermined amount of clear toner is applied to the application position designated by the clear toner form data.

  When the clear toner usage amount setting is a cost priority, out of the pixel positions where application is instructed by the clear toner form data, the pixel values of the color toner image data are excluded in advance from positions that are lower than a predetermined threshold. Clear toner image data is generated so that a predetermined amount of clear toner is applied.

  When the clear toner usage amount setting is glossy priority, based on the clear toner form data and the color toner image data, the clear toner image data is set so that the difference in the total adhesion amount between the color toner and the clear toner is reduced between adjacent pixels. Is generated. For example, as shown in FIG. 5, when there is a pixel for which application of clear toner is not instructed between pixels for which application of clear toner is instructed, the position where the adjacent pixel is not instructed for application of clear toner application Clear toner image data is generated such that an amount of clear toner corresponding to the difference in total adhesion amount is applied.

  When the clear toner usage setting is color reproduction priority, the total adhesion amount of the color toner and the clear toner of each pixel is calculated based on the clear toner form data and the color toner image data, and the calculated total adhesion amount is The clear toner image data is generated so that the clear toner is not applied to the position where the image forming unit 105 is larger than the maximum toner adhesion amount even if the clear toner application is instructed.

  When clear toner usage setting is paper type priority, based on clear toner form data and color toner image data, in addition to the position where clear toner application is instructed in clear toner form data, the position where clear toner application is not instructed Even so, the clear toner image data is generated so that the clear toner is applied to the pixels in the vicinity of the application position of the colored toner.

  Returning to FIG. 8, in step S3, a preview image is displayed on the display unit 114 (step S3).

FIG. 9 shows a block diagram of processing steps for displaying a preview image on the display unit 114.
In step S3, first, in the image forming unit 105 based on the clear toner form data and the clear toner image data, the clear toner usage amount instructed to be applied by the clear toner form data, and the clear toner image data. A difference from the amount of clear toner actually used is calculated (step T1).

  The difference amount calculated in step T1 is input to the timer unit 112, and the timer unit 112 generates a switching signal based on the difference amount of the clear toner usage amount (step T2). The switching signal is a signal that repeats OFF / ON at a constant cycle with OFF to ON as one cycle. When the difference amount of the clear toner use amount is zero, that is, when the clear toner use amount instructed to be applied by the clear toner form data is equal to the actually used clear toner use amount, a switching signal with the same OFF period and ON period is displayed as a timer. Generated by the unit 112. When the clear toner usage amount is negative, that is, when the clear toner usage amount actually used is larger than the clear toner usage amount instructed to be applied by the clear toner form data, the ON period is longer than the OFF period of the switching signal. A switching signal is generated by the timer unit 112. When the clear toner usage amount is positive, that is, when the clear toner usage amount actually used is smaller than the clear toner usage amount specified by the clear toner form data, the switching signal OFF period is longer than the ON period. A switching signal is generated by the timer unit 112.

In step T3, preview image data is generated based on the switching signal output from the timer unit 112 (step T3).
In step T3, a preview image is generated based on the color toner image data (RGB) and the clear toner image data. When the switching signal output from the timer unit 112 is OFF, the color toner image data is output as preview image data. When the switching signal output from the timer unit 112 is ON, the pixel value at the clear toner application position based on the clear toner image data in the color toner image data is inverted and output as preview image data. Here, to invert a pixel value means to convert a pixel value represented by a binary number from 1 to 0 and from 0 to 1. For example, in the case of decimal 0-255 image data, the pixel value 0 is converted to 255, and the pixel value 100 is converted to 155.

  In step T4, the resolution conversion process is performed on the preview image data based on the enlargement / reduction instruction input from the operation unit 113 (step T4). Then, the resolution-converted preview image data is output to the display unit 114 and displayed on the display unit 114 (step T5).

FIG. 10 is a timing chart of the switching signal output by the timer unit 112 and the display switching of the preview image.
FIG. 10A is a timing chart in the case where the clear toner usage amount based on the clear toner form data and the clear toner usage amount actually used in the image forming unit 105 are equal. For example, when one cycle of the switching signal is 1.0 [second], the switching signal is OFF during 0 to 0.5 [second], and during this time, it is based on the color toner image data that is not processed. A colored toner image is displayed as a preview image. When the switching signal is turned ON after 0.5 seconds, the preview display is switched, and the color toner image data is changed until the switching signal is subsequently turned OFF (between 0.5 seconds and 1.0 second). A clear toner confirmation image obtained by inverting the pixel value at the clear toner application position is displayed as a preview image. Thereafter, the color toner image and the clear toner confirmation image are alternately and repeatedly displayed by this display cycle.

  FIG. 10B is a timing chart when the clear toner usage amount actually used in the image forming unit 105 is increased from the clear toner usage amount based on the clear toner form data. In this case, the switching signal is OFF during 0 to 0.3 [seconds], and a color toner image based on the color toner image data that is not processed is displayed as a preview image. When 0.3 seconds elapses and the switching signal is switched ON, the preview image is switched, and the color toner image is switched until the switching signal is subsequently turned OFF (between 0.3 seconds and 1.0 second). A clear toner confirmation image obtained by reversing the pixel value of the clear toner application position in the data is switched and displayed on the display unit 114 as a preview image. Thereafter, the color toner image and the clear toner confirmation image are alternately and repeatedly displayed by this display cycle.

  FIG. 10C is a timing chart when the clear toner usage amount actually used in the image forming unit 105 is reduced from the clear toner usage amount based on the clear toner form data. In this case, the switching signal is OFF during 0 to 0.7 [seconds], and the color toner image is displayed as a preview image based on the color toner image data that is not processed. When 0.7 seconds elapses and the switching signal is turned ON, the preview image is switched, and the color toner image is changed until the switching signal is subsequently turned OFF (between 0.7 seconds and 1.0 seconds). A preview image obtained by inverting the pixel value of the clear toner application position in the data is switched and displayed on the display unit 114. Thereafter, the color toner image and the clear toner confirmation image are alternately and repeatedly displayed by this display cycle.

As shown in FIGS. 10A to 10C, whether the clear toner usage amount actually used in the image forming unit 105 is equal to, increases, or decreases as the clear toner usage amount based on the clear toner form data. Thus, the display time of the color toner image and the display time of the clear toner confirmation image are controlled. Specifically, when the clear toner usage amount actually used in the image forming unit 105 is equal to the clear toner usage amount based on the clear toner form data, the display time of the clear toner confirmation image and the display time of the color toner image are displayed. Are controlled to be equal to each other. When the clear toner usage amount actually used in the image forming unit 105 is larger than the clear toner usage amount based on the clear toner form data, the display time of the clear toner confirmation image is controlled to be longer than the display time of the colored toner image. Is done. When the clear toner usage amount actually used in the image forming unit 105 is smaller than the clear toner usage amount based on the clear toner form data, the display time of the clear toner confirmation image is controlled to be shorter than the display time of the colored toner image. Is done.
Therefore, the user intuitively determines the clear toner usage amount in the image forming unit 105 depending on whether the display time of the clear toner confirmation image is equal to, longer, or shorter than the display time of the color toner image. It is possible to recognize whether it is equivalent to that instructed by, whether it increases or decreases.

FIGS. 11 to 12 show display examples of preview images on the display unit 114.
FIG. 11 shows a display example when the clear toner application position matches the position of the character ABCDE by the colored toner image. The upper part of FIG. 11 is a preview image (colored toner image) displayed when the switching signal of the timer unit 112 is OFF. The lower part of FIG. 11 is a preview image (clear toner confirmation image) displayed when the switching signal of the timer unit 112 is ON.
When the switching signal is OFF, first, the colored toner image shown in the upper part of FIG. Thereby, the user can confirm the finished image of the image formed on the paper. Next, the clear toner confirmation image shown in the lower part of FIG. 11 is displayed on the display unit 114 in response to the switching signal being switched ON. In the clear toner confirmation image, the color at the clear toner application position is different from that of the color toner image, specifically, a color obtained by inverting the pixel value at the clear toner application position in the color toner image. The upper and lower images in FIG. 11 are repeatedly displayed alternately on the same screen of the display unit 114.

FIG. 12 shows a display example in the case where the clear toner application position is in a range slightly larger than the character ABCDE by the colored toner image. The upper part of FIG. 12 is a preview image (colored toner image) displayed when the switching signal of the timer unit 112 is OFF. The lower part of FIG. 12 is a preview image (clear toner confirmation image) displayed when the switching signal of the timer unit 112 is ON.
When the switching signal is OFF, first, the colored toner image shown in the upper part of FIG. Thereby, the user can confirm the finished image of the image formed on the paper. Next, the clear toner confirmation image shown in the lower part of FIG. 12 is displayed on the display unit 114 in response to the switching signal being switched ON. In the clear toner confirmation image, the color of the clear toner application position is different from that of the color toner image. Specifically, the clear toner application position protruding from the characters ABCDE by the color toner image is the pixel value (density) of the color toner image. Value) expressed by 255 colors obtained by reversing 0, and the clear toner application position overlapping the characters ABCD is represented by colors obtained by reversing the pixel values of the colored toner image. The upper and lower images in FIG. 12 are alternately and repeatedly displayed on the same screen of the display unit 114.

As shown in FIGS. 11 to 12, in the preview display according to the present embodiment, a color toner image and a clear toner confirmation image obtained by inverting the pixel value of the clear toner application position in the color toner image are displayed on the display unit. 114 are alternately switched and displayed at the same position on the same screen, so that the user can easily recognize the clear toner application position while imaging the finished image. In particular, when the clear toner application position is slightly larger or slightly smaller than the position of an object such as a character in a colored toner image, there is a problem that it is difficult for the user to grasp the difference in the conventional technology. In the embodiment, the clear toner application position appears as a color change of the colored toner image, so that the user can surely grasp the fine clear toner application position.
Further, when the clear toner usage amount actually used is equal to the clear toner usage amount instructed to be applied by the clear toner form data, the color toner image and the clear toner confirmation image are switched and displayed at the same time, When the clear toner usage amount actually used increases with respect to the clear toner usage amount instructed to be applied by the clear toner form data, the clear toner confirmation image is displayed for a longer time, and the clear toner form data is applied. When the clear toner usage amount actually used decreases with respect to the clear toner usage amount instructed, the clear toner confirmation image is displayed in a shorter time. Whether clear toner usage increases or decreases from the indication depending on the length, or It is equivalent to or a user is able to easily grasp on the screen of the preview image.

Returning to FIG. 8, in step S <b> 4, it is determined whether the end of preview display is instructed by the operation unit 113. If it is determined that the end of the preview display is not instructed (step S4; NO), it is determined whether or not the operation unit 113 has instructed to change the clear toner usage amount setting (step S5). If it is determined that the change of the clear toner usage amount setting is not instructed by the operation unit 113 (step S5; NO), the process returns to step S3. If it is determined that the change of the clear toner usage amount is instructed by the operation unit 113 (step S5; YES), the clear toner image data is regenerated based on the instructed clear toner usage amount setting (step S6). The process returns to step S3, and a preview image is displayed on the display unit 114 based on the newly generated clear toner image data, color toner image data, and clear toner form data.
When it is determined that the end of the preview display is instructed by the operation unit 113 (step SS4; YES), the preview display process ends.

As described above, according to the image forming apparatus 1, the control unit 110 generates clear toner image data based on the color toner image data and the clear toner form data, and responds to the switching signal from the timer unit 112. For clear toner confirmation, the color toner image based on the color toner image data and the color of the pixel at the clear toner application position in the generated clear toner image data are displayed in a color different from the color of the pixel in the color toner image. The images are alternately switched and displayed on the display unit 114 as a preview image. For example, a clear toner confirmation image is displayed in which the color of the pixel at the clear toner application position in the clear toner image data is displayed by inverting the pixel value at the clear toner application position in the colored toner image.
Therefore, the color toner image and the clear toner confirmation image in which the color of the clear toner application position in the color toner image is displayed in a different color are alternately displayed at the same position on the same screen of the display unit 114. Makes it possible to reliably recognize the delicate clear toner application position while imagining the finished image formed on the paper.

Further, the image forming apparatus 1 includes an operation unit 113 for the user to set the clear toner usage amount of the image forming unit 105 with respect to the clear toner usage amount based on the clear toner form data. Generates the color toner image data based on the color toner image data, the clear toner form data, and the setting from the operation unit 113, the color toner image based on the color toner image data, and the generated clear toner image A clear toner confirmation image in which the color of the pixel at the clear toner application position in the data is displayed in a color different from the color of the pixel in the colored toner image is alternately switched and displayed on the display unit 114 as a preview image.
Therefore, the user can easily recognize the clear toner application position according to the setting of the clear toner usage amount.

  In addition, the timer unit 112 increases or decreases the ON time or OFF time of the switching signal according to the difference between the clear toner usage amount based on the clear toner form data and the clear toner usage amount based on the clear toner image data. Accordingly, since the display length of each of the color toner image and the clear toner confirmation image varies depending on the difference, the user actually uses the clear toner usage amount instructed by the clear toner form data in the image forming unit 105. It is possible to easily recognize whether the clear toner usage amount increases or decreases.

  In addition, when the setting of the clear toner usage amount is changed by the operation unit 113, the control unit 110 regenerates the clear toner image data based on the changed setting of the clear toner usage amount, and the color toner image The color toner image based on the data and the clear toner confirmation image based on the regenerated clear toner image data are alternately switched and displayed on the display unit 114 as a preview image. Therefore, the user can confirm the change in the setting of the clear toner usage amount in real time.

  Note that the description in the above embodiment shows a preferred example of the image forming apparatus according to the present invention, and the present invention is not limited to this.

  For example, the control unit 110 performs various processes such as RIP processing, clear toner image data generation, clear toner usage difference calculation, preview image generation, resolution conversion, and the like by software processing in cooperation with the CPU and the program. Although described as performing, it is good also as a structure provided with the hardware which performs each of these processes.

  In the above description, an example in which a ROM, a nonvolatile memory, a hard disk, or the like is used as a computer-readable medium for the program according to the present invention is disclosed, but the present invention is not limited to this example. As another computer-readable medium, a portable recording medium such as a CD-ROM can be applied. A carrier wave is also applied as a medium for providing program data according to the present invention via a communication line.

  In addition, the detailed configuration and detailed operation of each device can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 101 Image reading part 102 Input image processing part 103 Image memory part 104 Output image processing part 105 Image forming part 106 Bus 107 HDD
108 Communication unit 109 PC
110 Control unit 111 Storage unit 112 Timer unit 113 Operation unit 114 Display unit

Claims (6)

Based on the image data for color toner and the image data for clear toner, an image forming unit for forming an image composed of a color toner image and a clear toner image on a sheet, and a preview image of the image formed by the image forming unit An image forming apparatus including a display unit for displaying,
A timer unit that outputs an ON / OFF switching signal at a constant cycle;
An operation unit for a user to set a clear toner usage amount of the image forming unit with respect to a reference based on a clear toner usage amount based on clear toner form data indicating a clear toner application position in the color toner image data When,
The image data for the clear toner is generated based on the image data for the color toner, the clear toner form data, and the setting from the operation unit, and the color toner for the color toner is generated according to a switching signal from the timer unit. And a clear toner confirmation image in which the color of the pixel at the clear toner application position in the generated clear toner image data is displayed in a color different from the color of the pixel in the color toner image. And a control unit that alternately switches and displays the preview image on the display unit,
An image forming apparatus comprising:   The control unit displays the color of the pixel at the clear toner application position in the generated clear toner image data in a color obtained by inverting the pixel value at the clear toner application position in the colored toner image. The image forming apparatus according to claim 1, wherein an image is displayed. The timer unit increases or decreases an ON time or an OFF time of the switching signal according to a difference between a clear toner usage amount based on the clear toner form data and a clear toner usage amount based on the clear toner image data. Item 3. The image forming apparatus according to Item 1 or 2 . When the setting of the clear toner usage amount is changed by the operation unit, the control unit regenerates the image data for the clear toner based on the changed setting of the clear toner usage amount, and the color toner The color toner image based on the image data for use and the clear toner confirmation image based on the regenerated image data for the clear toner are alternately switched and displayed on the display unit as a preview image . the image forming apparatus according to any one of 3. The image according to any one of claims 1 to 4 , wherein the operation unit can be set to increase a clear toner usage amount of the image forming unit based on a clear toner usage amount based on the clear toner form data. Forming equipment. The image according to any one of claims 1 to 4 , wherein the operation unit can be set to decrease the clear toner usage amount of the image forming unit with reference to the clear toner usage amount based on the clear toner form data. Forming equipment.

Images