Patent Publication Number: US-10310404-B2

Title: Image forming apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a Continuation of application Ser. No. 15/257,065 filed on Sep. 6, 2016, the entire contents of which are incorporated herein by reference. 
    
    
     FIELD 
     Embodiments described herein relate generally to an image forming apparatus. 
     BACKGROUND 
     Conventionally, there is an image forming apparatus such as a multi-function peripheral (hereinafter, referred to as an “MFP”) and a printer. The image forming apparatus is equipped with an image forming section for forming an image on an image receiving medium. The image forming apparatus is equipped with an ordinary light source for emitting visible light to the image receiving medium discharged from the image forming section. 
     In some instances, there is an image on the image receiving medium such as a barcode for sorting postcards which is desired not to be visually recognized through irradiation of the visible light. In this case, an image that is visually recognizable through irradiation of a specific light such as UV light is formed on the image receiving medium. However, in a case in which the image on the image receiving medium is visually recognizable through the irradiation of the specific light, when the discharged image receiving medium is irradiated with the visible light, there is a possibility that whether the image is normally printed on the image receiving medium cannot be confirmed. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an external view illustrating an example of an image forming apparatus according to an embodiment; 
         FIG. 2  is a diagram illustrating an example of the schematic configuration of the image forming apparatus according to the embodiment; 
         FIG. 3  is a block diagram illustrating an example of the schematic configuration of functional blocks of the image forming apparatus according to the embodiment; 
         FIG. 4  is a diagram illustrating an example of a back surface of a sheet discharged to a discharge tray according to the embodiment; and 
         FIG. 5  is a diagram illustrating an example of a front surface of the sheet discharged to the discharge tray according to the embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In accordance with an embodiment, an image forming apparatus comprises an image forming section and a specific light source. The image forming section forms an image on an image receiving medium with specific material which emits visible light through irradiation by specific light. The specific light source emits the specific light to the image receiving medium at a downstream side of the image forming section in a conveyance direction of the image receiving medium. 
     In accordance with another embodiment, an image forming method involving forming an image on an image receiving medium with a specific material which emits visible light through irradiation by specific light; and emitting the specific light to the image receiving medium at a downstream position in a conveyance direction of the image receiving medium. 
     Hereinafter, an image forming apparatus  1  of an embodiment is described with reference to the accompanying drawings. Further, the same component is assigned with the same mark in each diagram. 
       FIG. 1  is an external view illustrating an example of the image forming apparatus  1  according to the embodiment. For example, the image forming apparatus  1  is an MFP (Multi-Function Peripheral). The image forming apparatus  1  reads an image formed on a sheet-like image receiving medium (hereinafter, referred to as a “sheet”) such as a paper to generate digital data (image file). The image forming apparatus  1  forms an image on the sheet with toner based on the digital data. 
       FIG. 2  is a diagram illustrating an example of the schematic configuration of the image forming apparatus  1  according to the embodiment. The image forming apparatus  1  is an electrophotographic type image forming apparatus. 
     The image forming apparatus  1  is equipped with an image reading section  10 , a control panel  20 , a sheet housing section  30 , a conveyance section  40 , an image forming section  50 , a fixing section  60 , a reversing unit  70 , a discharge tray  80 , an irradiation section  90  and a control section  100 . 
     First, the image reading section  10  is described. 
     The image reading section  10  reads an image formed on the sheet with a sensor to generate digital data. For example, the image reading section  10  is a color scanner. The color scanner includes a CIS (Contact Image Sensor), a CCD (Charge Coupled Device) and the like. 
     Next, the control panel  20  is described. 
     As shown in  FIG. 1 , the control panel  20  is equipped with a display section  21  and an operation section  22 . 
     The display section  21  operates as an output interface to display characters or images. The display section  21  displays various information relating to the image forming apparatus  1 . For example, the display section  21  is a display device such as a liquid crystal display and an organic EL (Electro Luminescence) display. 
     The operation section  22  operates as an input interface to receive an instruction from a user. The operation section  22  outputs a signal corresponding to an operation executed by the user to the control section  100  (refer to  FIG. 2 ). Further, the display section  21  and the operation section  22  may be constituted as an integrated touch panel. 
     Next, the sheet housing section  30  is described. 
     The sheet housing section  30  is equipped with a plurality of (for example, two in the present embodiment) sheet feed cassettes  31  and  32 . 
     As shown in  FIG. 2 , the sheet feed cassettes  31  and  32  respectively house sheets S with prescribed sizes and categories. The sheet feed cassettes  31  and  32  are equipped with pickup rollers  31   a  and  32   a , respectively. The pickup rollers  31   a  and  32   a  respectively pick out the sheets S from the sheet feed cassettes  31  and  32  one by one. The pickup rollers  31   a  and  32   a  supplies the sheet S picked out to the conveyance section  40 . 
     Next, the conveyance section  40  is described. 
     The conveyance section  40  conveys the sheet S between the sheet housing section  30  and the image forming section  50 . the conveyance section  40  is equipped with sheet feed rollers  41  and  42 , a conveyance roller  43  and a resist roller  44 . The sheet feed rollers  41  and  42  respectively convey the sheet S supplied by the pickup rollers  31   a  and  32   a  to the resist roller  44 . The resist roller  44  supplies the sheet S to the image forming section  50 . In detail, the resist roller  44  conveys the sheet S to a transfer roller  54  side according to timing at which the transfer roller  54  of the image forming section  50  transfers a toner image onto the sheet S. The resist roller  44  conveys the sheet S to the transfer roller  54  side after front end of the sheet S is aligned at a nip N. 
     Next, the image forming section  50  is described. 
     The image forming section  50  forms an image on the sheet S with the toner. The image forming section  50  forms an image based on image data read by the image reading section  10  or image data received from an external device. For example, the image formed on the sheet S is an output image referred to as a hard copy, print out and the like. 
     Next, the toner is described. 
     In the present embodiment, the toner includes UV toner (specific material) and ordinary toner (ordinary material). 
     The UV toner has a characteristic of emitting visible light through irradiation by UV light (specific light). In other words, the UV toner is the toner that is visually non-recognizable through irradiation by visible light and is visually recognizable through irradiation by UV light. The UV toner may be optional toner as long as the toner has the characteristic described above. UV light (specific light in this disclosure) has a wavelength from 10 to 380 nm. Visible light has a wavelength from 400 to 700 nm. 
     The ordinary toner is visually recognizable toner through irradiation by visible light. For example, the ordinary toner is yellow (Y), magenta (M), cyan (C), black (K) toner. 
     Next, the configuration of the image forming section  50  is described. 
     The image forming section  50  is equipped with an exposure section  51 , a toner cartridge  52 , an image forming section  53  and the transfer roller  54 . 
     The exposure section  51  irradiates (exposes) a photoconductive drum  53   b  of the image forming section  53  with the light. The exposure section  51  is equipped with an exposure light source such as a laser or an LED. 
     The toner cartridge  52  houses toner with the category thereof corresponding to the toner to be handled. In the present embodiment, the toner cartridge  52  houses the UV toner and the ordinary toner. 
     The image forming section  53  forms the image with the toner. 
     The image forming section  53  is equipped with a developing device  53   a , the photoconductive drum  53   b , a charger  53   c  and a cleaning blade  53   d.    
     The developing device  53   a  houses developing agent. The toner is contained in the developing agent. The developing device  53   a  attaches the toner to the photoconductive drum  53   b.    
     The photoconductive drum  53   b  is one of concrete examples of an image carrier (image bearing module). The photoconductive drum  53   b  has a photoconductor (photoconductive area) on the outer peripheral surface thereof. For example, the photoconductor is an OPC (organic photoconductor). 
     The charger  53   c  uniformly charges the surface of the photoconductive drum  53   b.    
     The cleaning blade  53   d  removes the toner attached to the photoconductive drum  53   b.    
     Next, operations of the image forming section  53  are schematically described. 
     The photoconductive drum  53   b  is charged to a predetermined electric potential by the charger  53   c . Next, the light from the exposure section  51  is emitted to the photoconductive drum  53   b . In this way, the electric potential of the area which is irradiated with the light in the photoconductive drum  53   b  changes. Through the change, an electrostatic latent image is formed on the surface of the photoconductive drum  53   b . The electrostatic latent image formed on the surface of the photoconductive drum  53   b  is developed through the developing agent in the developing device  53   a . In other words, the image developed by the toner (hereinafter, referred to as a “developed image”) is formed on the surface of the photoconductive drum  53   b.    
     The transfer roller  54  faces the photoconductive drum  53   b . The transfer roller  54  transfers the developed image formed on the surface of the photoconductive drum  53   b  onto the sheet S. 
     Next, the fixing section  60  is described. 
     The fixing section  60  applies heat and pressure to the sheet S. The fixing section  60  fixes the toner image transferred onto the sheet S through the heat and the pressure. The sheet S on which the image is fixed through the fixing section  60  is discharged to the discharge tray  80 . Alternatively, the sheet S on which the image is fixed through the fixing section  60  is conveyed to the reversing unit  70 . 
     Next, the reversing unit  70  (discharge mechanism) is described. 
     The reversing unit  70  reverses the sheet S conveyed from the fixing section  60  through switchback. The reversing unit  70  conveys the reversed sheet S to the front of the resist roller  44  again. The reversing unit  70  reverses the sheet S to form a toner image on the back surface of the sheet S to which the fixing processing is executed. Alternatively, the reversing unit  70  discharges the sheet S to the discharge tray  80  so as to irradiate a printing surface of the sheet S with the UV light. 
     Next, the discharge tray  80  is described. 
     The discharge tray  80  is positioned at the downstream side of the image forming section  50  in the conveyance direction of the sheet S. Herein, the “downstream side” refers to the downstream side of the fixing section  60  in the conveyance direction of the sheet S in a case in which the sheet S passing the fixing section  60  is discharged to the discharge tray  80 . 
     The discharge tray  80  is a discharge tray in a body. In other words, the discharge tray  80  is positioned at the inside of a casing (inside of a main body) of the image forming apparatus  1 . An outlet  80   a  of the sheet S discharged to the discharge tray  80  is formed in the image forming apparatus  1 . The outlet  80   a  is opened at a lateral side of the casing of the image forming apparatus  1  in a manner of facing the discharge tray  80 . 
     Next, the irradiation section  90  is described. 
     The irradiation section  90  is equipped with a specific light source  91  and an ordinary light source  92 . 
     The specific light source  91  irradiates the sheet S with the UV light at the downstream side of the image forming section  50  in the conveyance direction of the sheet S. The specific light source  91  irradiates the sheet S discharged to the discharge tray  80  with the UV light. The specific light source  91  is a UV light (otherwise known as black light). 
     The specific light source  91  emits the UV light towards the sheet S from the outlet  80   a . In other words, the irradiation section of the UV light in the specific light source  91  faces an opposite side to the outlet  80   a . The whole sheet S discharged to the discharge tray  80  is irradiated with the UV light from the specific light source  91 . 
     The ordinary light source  92  emits the visible light to the sheet S at the downstream side of the image forming section  50  in the conveyance direction of the sheet S. The ordinary light source  92  emits the visible light to the sheet S discharged to the discharge tray  80 . For example, the ordinary light source  92  is an LED. 
     The ordinary light source  92  emits the visible light towards the sheet S from the reversing unit  70  side. In other words, the irradiation section of the visible light in the ordinary light source  92  faces the outlet  80   a  side. The whole sheet S discharged to the discharge tray  80  is irradiated with the visible light from the ordinary light source  92 . 
       FIG. 3  is a block diagram illustrating an example of the schematic configuration of functional blocks of the image forming apparatus  1  according to the embodiment. 
     The control section  100  is connected with each functional section via a system bus  2  in a data communicable manner. The control section  100  controls each functional section. The functional sections include the image reading section  10 , the control panel  20 , the image forming section  50 , a discharge control section  101 , an irradiation timing control section  102 , a ROM (Read Only Memory)  110  and a DRAM (Dynamic Random Access Memory)  120 . 
     Hereinafter, an example of the processing of the control section  100  is described. 
     The control section  100  controls each functional section based on an output signal from the control panel  20 . 
     For example, the control section  100  controls the pickup rollers  31   a  and  32   a  (refer to  FIG. 2 ) to convey the sheet S from the sheet feed cassettes  31  and  32  in response to the instruction from the user. 
     For example, the control section  100  controls to switch a print mode. Hereinafter, as categories of the print mode, a mode in which the image is formed on the sheet S with the UV toner is referred to as a “UV print mode (specific print mode)”, and a mode in which the image is formed on the sheet S with the ordinary toner is referred to as an “ordinary print mode”. 
     The operation section  22  is equipped with a mode selection section  22   a  capable of selecting the UV print mode and the ordinary print mode. For example, the mode selection section  22   a  is a button arranged on the operation section  22 . Through pressing the button to select the “UV print mode” at the time of selecting the print mode by the user, the control section  100  controls the image forming section  50  to form the image on the sheet S with the UV toner. on the other hand, through pressing a button to select the “ordinary print mode” at the time of selecting the print mode by the user, the control section  100  controls the image forming section  50  to form the image on the sheet S with the ordinary toner image. 
     For example, the control section  100  controls to switch the irradiation section  90  (refer to  FIG. 2 ). 
     The operation section  22  is equipped with a light source switching section  22   b  capable of switching the specific light source  91  and the ordinary light source  92 . For example, the light source switching section  22   b  is a button arranged on the operation section  22 . Through pressing the button to select the “UV light” by the user, the control section  100  controls the irradiation section  90  to enable the specific light source  91  to emit the UV light. On the other hand, through pressing the button to select the “visible light” by the user, the control section  100  controls the irradiation section  90  to enable the ordinary light source  92  to emit the visible light. 
     For example, the control section  100  controls the reversing unit  70  to discharge the sheet S to the discharge tray  80  (refer to  FIG. 2 ) so that the printing surface of the sheet S is irradiated with the UV light. In other words, the control section  100  controls the reversing unit  70  to reverse the sheet S to which the fixing processing is executed to the discharge tray  80 . 
     Herein, an example of the function of the reversing unit  70  is described. 
       FIG. 4  is a diagram illustrating an example of the back surface of the sheet S discharged to a discharge tray according to the embodiment. 
     Hereinafter, a case in which UV printing is carried out to one surface (front surface) of the sheet S, and the UV printing is not carried out to the other surface (back surface) of the sheet S is referred to as “UV simplex printing”. In a case of the UV simplex printing, if the sheet S to which the fixing processing is executed is not reversed, the sheet S is discharged to the discharge tray  80  in a state of the back surface. Therefore, even the UV light from the specific light source  91  is emitted to the sheet S, the UV light is blocked by the back surface of the sheet S. Therefore, the printing surface (front surface) of the sheet S is not irradiated with the UV light. 
       FIG. 5  is a diagram illustrating an example of the front surface of the sheet S discharged to the discharge tray  80  according to the embodiment. 
     In the present embodiment, through the control of the reversing unit  70 , the sheet S to which the fixing processing is executed is reversed to be discharged to the discharge tray  80 . Therefore, the sheet S is discharged to the discharge tray  80  in the state of the front surface. Therefore, the UV light from the specific light source  91  is emitted to the printing surface (front surface) of the sheet S. 
     Next, the discharge control section  101  is described. 
     As shown in  FIG. 3 , the control section  100  controls the discharge control section  101  at the time a plurality of the sheets S is discharged. The discharge control section  101  controls the printing and discharge operation executed to a plurality of the sheets S in such a manner that the sheets S are discharged to the discharge tray  80  in order starting from the final sheet S at the time a plurality of the sheets S is discharged. 
     Next, the irradiation timing control section  102  is described. 
     The control section  100  controls the irradiation timing control section  102  at the time the UV light is emitted to the sheet S. The irradiation timing control section  102  controls the timing at which the UV light is emitted to the sheet S immediately after the sheet S is discharged to the discharge tray  80 . The irradiation timing control section  102  controls the specific light source  91  to emit the UV light to the sheet S immediately after the sheet S is discharged to the discharge tray  80 . 
     The ROM  110  stores various control programs necessary for the control section  100  to operate. 
     The DRAM  120  is used as a temporary storage area of data at the time the control section  100  executes the program. 
     Incidentally, there is an image on the image receiving medium such as a barcode for sorting postcards which is desired to be not visually recognized through irradiation of the visible light. In this case, an image that is visually recognizable through irradiation of the specific light such as UV light is formed on the image receiving medium. However, in a case in which the image on the image receiving medium is visually recognizable through the irradiation of the specific light, even the discharged image receiving medium is irradiated with the visible light, there is a possibility that whether the image is normally printed on the image receiving medium cannot be confirmed. 
     According to the embodiment, the image forming apparatus is equipped with the image forming section  50  and the specific light source  91 . The image forming section  50  forms the image on the sheet S with the UV toner which emits the visible light through the irradiation of the UV light. The specific light source  91  emits the UV light to the sheet S at the downstream side of the image forming section  50  in the conveyance direction of the sheet S. With the foregoing configuration, the following effect is achieved. In a case in which the image on the sheet S is visually recognizable through the irradiation of the UV light, through emitting the UV light to the discharged sheet S, the image on the sheet S can be visually recognized. Thus, whether the image is normally printed on the sheet S can be confirmed. 
     The specific light source  91  emits the UV light to the sheet S discharged to the discharge tray  80 , and thus, the following effect is achieved. As the UV light can be emitted to the sheet S in a state in which the sheet S is still, whether the image is normally printed on the sheet S is easily confirmed. In addition, compared with a case in which the UV light is emitted to the sheet S when the sheet S is being conveyed, the UV light is easily emitted to the sheet S. 
     The image forming apparatus  1  is equipped with the reversing unit  70  configured to discharge the sheet S to the discharge tray  80  so as to irradiate the printing surface of the sheet S with the UV light, and thus, the following effect is achieved. As the UV light from the specific light source  91  is emitted to the printing surface of the sheet S, the image on the sheet S can be easily visually recognized. 
     The image forming apparatus  1  is equipped with the discharge control section  101  configured to control the printing and the discharge operation executed to a plurality of the sheets S in such a manner that the sheets S are discharged to the discharge tray  80  in order starting from the final sheet S at the time a plurality of the sheets S is discharged. With the foregoing configuration, the following effect is achieved. Even in a case in which a plurality of the sheets S is discharged to the discharge tray  80  in such a manner that the printing surfaces of the sheets S are irradiated with the UV light, the order of the pages is prevented from being reversed. 
     The specific material is the UV toner, and the specific light source  91  is the UV light, and thus, the following effect is achieved. Whether the image is normally printed on the sheet S can be confirmed with a simple configuration using the UV toner and the UV light. 
     The image forming apparatus  1  is equipped with the mode selection section  22   a  capable of selecting the UV print mode and the ordinary print mode, and thus, the following effect is achieved. The print mode can be easily selected matching with needs of the user. 
     The image forming apparatus  1  is equipped with the light source switching section  22   b  capable of switching the specific light source  91  and the ordinary light source  92 , and thus, the following effect is achieved. The light emitted to the sheet S can be easily switched to at least one of the UV light and the visible light matching with needs of the user. 
     The discharge tray  80  is the discharge tray in the body, and thus, the following effect is achieved. As the discharge tray  80  is positioned at the inside of the casing (inside of the main body) of the image forming apparatus  1 , the compactification of the image forming apparatus  1  can be realized. 
     The image forming apparatus  1  is equipped with the irradiation timing control section  102  configured to control the timing at which the UV light is emitted to the sheet S immediately after the sheet S is discharged to the discharge tray  80 , and thus, the following effect is achieved. Compared with a case in which the UV light is emitted to the sheet S after prescribed time elapses from the moment the sheet S is discharged to the discharge tray  80 , as the UV light is emitted to the sheet S for a long time, the image on the sheet S can be easily visually recognized. 
     The specific light source  91  emits the UV light towards the sheet S from the outlet  80   a  of the sheet S, and thus, the following effect is achieved. In a case of taking out the sheet S from the outlet  80   a  by the user, it can be prevented that the user looks at the UV light directly. Thus, the image on the sheet S can be easily visually recognized from the outlet  80   a.    
     Hereinafter, modifications are described. 
     The specific light source  91  is not limited to emitting the UV light to the sheet S discharged to the discharge tray  80 . For example, the specific light source  91  may emit the UV light to the sheet S when the sheet S is being conveyed. In this case, the interval between the sheets S or the conveyance speed of the sheet S may be changeable so as to easily visually recognize the sheet S that is being conveyed. 
     The discharge tray  80  is not limited to the discharge tray in the body. For example, the discharge tray may protrude towards the outside of the casing (outside of the main body) of the image forming apparatus  1 . 
     The ordinary light source  92  is not limited to emitting the visible light towards the sheet S from the reversing unit  70  side. For example, the ordinary light source  92  may emit the visible light towards the sheet S from the outlet  80   a.    
     According to at least one embodiment described above, the image forming apparatus is equipped with the image forming section  50  and the specific light source  91 . The image forming section  50  forms the image on the sheet S with the UV toner which emits the visible light through the irradiation of the UV light. The specific light source  91  emits the UV light to the sheet S at the downstream side of the image forming section  50  in the conveyance direction of the sheet S. With the foregoing configuration, the following effect is achieved. In a case in which the image on the sheet S is visually recognizable through the irradiation of the UV light, through emitting the UV light to the discharged sheet S, the image on the sheet S can be visually recognized. Thus, whether the image is normally printed on the sheet S can be confirmed. 
     Other than in the operating examples, or where otherwise indicated, all numbers, values and/or expressions referring to quantities of ingredients, reaction conditions, etc., used in the specification and claims are to be understood as modified in all instances by the term “about.” 
     While certain embodiments have been described these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms: furthermore various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and there equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.