JP2005335869A - Medium determination device, and method for determination of medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To correctly determine the kind of a medium (the medium to be printed next) positioned on top even when thin media are stacked on each other. <P>SOLUTION: This medium determination device is provided with a light source to radiate light to the medium, and a detection part to detect light generated from fluorescent agent when light from the light source is radiated to the media including the fluorescent agent. Based on result of detection by the detection part, the kind of the medium is determined. The incidence angle of the light radiated from the light source to be incident to the medium is varied based on the thickness of the medium. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a medium determination device and a medium determination method.

There is a medium discriminating apparatus that discriminates the type of a medium based on the amount of the fluorescent agent contained in the medium by paying attention to the fluorescent agent contained in the medium. In such a medium discrimination device, the amount of the fluorescent agent contained in the medium is detected by irradiating the medium with light and detecting the light emitted from the fluorescent agent. Then, based on the detected amount of the fluorescent agent, the type of the medium is determined.
JP 2002-167082 A

  In this way, in the medium discriminating apparatus that discriminates the type of the medium based on the amount of the fluorescent agent contained in the medium, the light that reaches the inside of the medium is smaller when the incident angle of the light irradiated on the medium is smaller. A large amount of the fluorescent agent contained in the medium can be excited. Therefore, in order to determine the type of the medium based on the amount of the fluorescent agent contained in the medium, it is preferable that the incident angle of the light irradiated on the medium is small.

  However, when thin media are stacked, if the incident angle of light is small, the light passes through the medium positioned at the top and reaches the medium stacked below it. In this case, the light also excites the fluorescent agent contained in the medium stacked below. Therefore, the medium discriminating apparatus cannot accurately detect the amount of the fluorescent agent contained in the medium positioned at the top, and cannot accurately determine the type of medium positioned at the top. was there.

  The present invention has been made in view of such circumstances, and even when thin media are stacked, the type of the medium positioned next (the medium to be printed next) is accurately determined. Is to be able to.

  A main invention for achieving the object is to detect light emitted from the fluorescent agent when the medium including the fluorescent agent is irradiated with light from the light source and the medium containing the fluorescent agent is irradiated with light from the light source. A medium discriminating apparatus that discriminates the type of the medium based on a detection result of the detection section, and the light emitted from the light source is based on the thickness of the medium. It is a medium discrimination | determination apparatus characterized by changing the incident angle which injects into this.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  At least the following matters will become apparent from the description of this specification and the accompanying drawings.

A light source that irradiates light to the medium, and a detection unit that detects light emitted from the fluorescent agent when the medium containing the fluorescent agent is irradiated with light from the light source. A medium discriminating apparatus that discriminates the type of the medium based on a detection result, wherein an incident angle at which light emitted from the light source is incident on the medium is changed based on a thickness of the medium. Media discrimination device.
In such a medium discriminating apparatus, it is possible to accurately discriminate the type of the medium positioned next (the medium to be printed next) even when thin media are stacked. Become.

The light source preferably irradiates the stacked medium with light.
In such a medium discriminating apparatus, the light source can irradiate the laminated medium with light.

The light source preferably irradiates the medium with ultraviolet rays.
In such a medium discriminating apparatus, more light can be emitted from the fluorescent agent by irradiating the medium with ultraviolet rays.

In addition, when the medium having different thickness is irradiated with light from the light source, the incident angle of the light irradiated to the thicker medium should be smaller than the incident angle of the light irradiated to the thinner medium. preferable.
In such a medium discriminating apparatus, when the medium having different thickness is irradiated with light from the light source, the incident angle of the light irradiated to the thicker medium is the light irradiated to the thinner medium. Therefore, the light can reach the inside of the medium and light can be emitted from the fluorescent agent inside the medium.

The light source is preferably movable so that the incident angle changes.
In such a medium discriminating apparatus, the light source is movable so that the incident angle changes.

Moreover, it is preferable that a plurality of light sources are provided, and each of the light sources is provided at a position where the incident angle is different.
In such a medium discriminating apparatus, it is possible to irradiate the medium with light from positions having different incident angles by a plurality of light sources.

And an infrared light source that irradiates the medium with infrared light, and a reflected light detection unit that detects infrared light reflected from the medium different from the detection unit. It is preferable to determine the type of the medium based on the detection result and the detection result of the reflected light detection unit.
In such a medium determination device, the type of the medium can be determined based on the detection result of the detection unit and the detection result of the reflected light detection unit.

And a light source for irradiating the medium with light, and a detection unit for detecting light emitted from the fluorescent agent when the medium containing the fluorescent agent is irradiated with light from the light source. A medium discriminating apparatus that discriminates a type of the medium based on a detection result of a portion, and changes an incident angle at which light emitted from the light source is incident on the medium based on a thickness of the medium; The light source irradiates the stacked medium with light, the light source irradiates the medium with ultraviolet light, and the medium having a different thickness is irradiated with light from the light source. The incident angle of the light applied to the light is smaller than the incident angle of the light applied to the thinner medium, and includes a plurality of light sources, and each of the light sources is provided at a position where the incident angles are different. It is also possible to realize a medium discrimination device characterized by
In this way, the effects of the present invention can be achieved most effectively because all the effects described above can be achieved.

Further, there is provided a medium determining method for determining the type of the medium based on a result of detecting light emitted from the fluorescent agent by irradiating the medium containing the fluorescent agent from a light source that irradiates the medium with light. Thus, it is possible to realize a medium discrimination method characterized by changing the incident angle at which the light emitted from the light source is incident on the medium based on the thickness of the medium.
The medium discrimination method realized in this way is a better method than the conventional method.

=== Overview of Printing Apparatus ===
As an embodiment of a printing apparatus that can use the medium discrimination apparatus according to the present invention, an outline of a printing system including a printer 1 and a computer 1100 will be described as an example.

  FIG. 1 is an explanatory diagram showing an external configuration of the printing system 1000. The printing system 1000 includes a printer 1 and a computer 1100. The computer 1100 includes a display device 1200, an input device 1300, and a recording / reproducing device 1400. The printer 1 is a printing apparatus that prints an image on a medium such as paper, cloth, or film. The computer 1100 is electrically connected to the printer 1 and outputs print data corresponding to the image to be printed to the printer 1 in order to cause the printer 1 to print an image. The display device 1200 includes a display and displays a user interface such as an application program or a printer driver. The input device 1300 is, for example, a keyboard 1300A or a mouse 1300B, and is used for operating an application program, setting a printer driver, or the like along a user interface displayed on the display device 1200. As the recording / reproducing apparatus 1400, for example, a flexible disk drive apparatus 1400A or a CD-ROM drive apparatus 1400B is used.

  A printer driver is installed in the computer 1100. The printer driver is a program for realizing a function of displaying a user interface on the display device 1200 and a function of converting image data output from an application program into print data. This printer driver is recorded on a recording medium (computer-readable recording medium) such as a flexible disk FD or a CD-ROM. Alternatively, the printer driver can be downloaded to the computer 1100 via the Internet. In addition, this program is comprised from the code | cord | chord for implement | achieving various functions.

=== Printer driver ===
<About the printer driver>
FIG. 2 is an explanatory diagram of a user interface of the printer driver. The user interface of the printer driver is displayed on the display device via the video driver. The user can make various settings of the printer driver using the input device 1300.

  The user can select a printing method from this screen. For example, the user can select a high-speed printing method or a fine printing method as the printing method. Then, the printer driver converts the image data into print data so that the format corresponds to the selected printing method.

  Further, the user can select the printing resolution (dot interval when printing) from this screen. For example, the user can select 180 dpi or 360 dpi as the print resolution from this screen. Then, the printer driver performs resolution conversion processing according to the selected resolution, and converts the image data into print data.

  Further, the user can select the type of printing paper used for printing from this screen. For example, the user can select plain paper or glossy paper as print paper.

  If the type of printing paper is different, the method of ink bleeding and drying is also different, so the amount of ink suitable for printing also differs. Therefore, the printer driver converts the image data into print data in accordance with the selected type of printing paper.

  As described above, the printer driver converts image data into print data in accordance with conditions set via the user interface. The user can make various settings of the printer driver from this screen, and can also know the remaining amount of ink in the cartridge.

=== Configuration of Printing Apparatus ===
<About the configuration of the printing device>
Next, the configuration of the printing apparatus will be described with reference to FIG. 3 and FIG. FIG. 3 is a block diagram of the overall configuration of the printer. FIG. 4 is a cross-sectional view of the overall configuration of the printer.

  Hereinafter, the basic configuration of the printer of this embodiment will be described. As shown in FIG. 3, the printer 1 of this embodiment includes a transport unit 20, a carriage unit 30, a head unit 40, a sensor group 50, and a controller 60. The printer 1 that has received the print data from the computer 1100 as an external device controls each unit (conveyance unit 20, carriage unit 30, head unit 40) by the controller 60. The controller 60 controls each unit based on the print data received from the computer 1100 and forms an image on a medium. The situation in the printer 1 is monitored by a sensor group 50, and the sensor group 50 outputs a detection result to the controller 60. The controller that receives the detection result from the sensor controls each unit based on the detection result.

  The transport unit 20 is for sending a medium (for example, paper) to a printable position and transporting the medium in a predetermined direction (hereinafter referred to as a transport direction) by a predetermined transport amount during printing. That is, the transport unit 20 functions as a transport mechanism that transports the medium. As shown in FIG. 4, the transport unit 20 includes a paper feed roller 21, a transport motor (also referred to as a PF motor), a transport roller 23, a platen 24, and a paper discharge roller 25. However, in order for the transport unit 20 to function as a transport mechanism, all of these components are not necessarily required. The paper feed roller 21 is a roller for automatically feeding the medium inserted into the paper insertion slot into the printer 1. The paper is inserted into the paper insertion slot in a stacked state, and the paper feed roller 21 feeds the paper located on the top of the stacked paper. The paper feed roller 21 has a D-shaped cross-sectional shape, and the length of the circumferential portion is set to be longer than the transport distance to the transport roller 23, and the medium is transported using this circumferential portion. 23 can be conveyed. The transport motor is a motor for transporting the medium in the transport direction, and is configured by a DC motor. The transport roller 23 is a roller that transports the medium fed by the paper feed roller 21 to a printable area, and is driven by a transport motor. The platen 24 supports the medium being printed. The paper discharge roller 25 is a roller that discharges the printed medium to the outside of the printer 1. The paper discharge roller 25 rotates in synchronization with the transport roller 23.

  The carriage unit 30 is for moving the head in a predetermined direction (hereinafter referred to as a carriage movement direction). The carriage unit 30 includes a carriage 31 and a carriage motor (also referred to as a CR motor). The carriage 31 can reciprocate. (Thus, the head moves along the carriage movement direction.) The carriage 31 detachably holds an ink cartridge that contains ink. The carriage motor is a motor for moving the carriage 31 in the carriage movement direction, and is constituted by a DC motor.

  The head unit 40 is for ejecting ink onto a medium. The head unit 40 has a head 41. The head 41 has a plurality of nozzles as ink discharge portions, and discharges ink intermittently from each nozzle. The head 41 is provided on the carriage 31. Therefore, when the carriage 31 moves in the carriage movement direction, the head 41 also moves in the carriage movement direction. Then, when the head 41 is intermittently ejected while moving in the carriage movement direction, dot lines (raster lines) along the carriage movement direction are formed on the medium.

  The sensor group 50 includes a linear encoder, a light emitting element 51, a light emitting element 52, a light receiving element 53, a rotary encoder 54 (see FIG. 4), a paper detection sensor 55 (see FIG. 4), and the like.

  The linear encoder is for detecting the position of the carriage 31 in the carriage movement direction. The rotary encoder 54 is for detecting the rotation amount of the transport roller 23. The paper detection sensor 55 is for detecting the position of the leading edge of the medium to be printed. The paper detection sensor 55 is provided at a position where the front end of the medium can be detected while the paper supply roller 21 is feeding the medium toward the transport roller 23. The paper detection sensor 55 is a mechanical sensor that detects the leading edge of the medium by a mechanical mechanism. More specifically, the paper detection sensor 55 has a lever that can rotate in the paper transport direction, and this lever is disposed so as to protrude into the medium transport path. Therefore, the leading edge of the medium comes into contact with the lever, and the lever is rotated. Therefore, the paper detection sensor 55 detects the position of the leading edge of the medium by detecting the movement of the lever. The light emitting element 51, the light emitting element 52, and the light receiving element 53 are provided in front of the sheet feeding roller 21 in the medium conveying direction. The light emitting element 51, the light emitting element 52, and the light receiving element 53 will be described in detail later with reference to FIG.

  The controller 60 is a control unit for controlling the printer 1. The controller 60 includes an interface unit 61, a CPU 62, a memory 63, and a unit control circuit 64. The interface unit 61 is for transmitting and receiving data between the computer 1100 as an external device and the printer 1. The CPU 62 is an arithmetic processing unit for controlling the entire printer 1. The memory 63 is used to secure an area for storing a program of the CPU 62, a work area, and the like, and includes a storage unit such as a RAM and an EEPROM. The CPU 62 controls each unit via the unit control circuit 64 in accordance with a program stored in the memory 63.

=== Medium Discriminating Device ===
<About the media discrimination device>
Next, the medium discrimination device will be described with reference to FIG. FIG. 5 is an explanatory diagram for describing the light-emitting element 51, the light-emitting element 52, and the light-receiving element 53 that constitute the medium discrimination device.

  First, with reference to FIG. 5, the light emitting element 51, the light emitting element 52, and the light receiving element 53 which comprise a medium discrimination | determination apparatus are demonstrated. The light emitting element 51 and the light emitting element 52 are, for example, ultraviolet LEDs having a peak emission wavelength of 370 nm. The light receiving element 53 is, for example, a silicon phototransistor.

  The light emitting element 51, the light emitting element 52, and the light receiving element 53 are provided in front of the sheet feeding roller 21 in the medium conveying direction in FIG. Therefore, light is emitted from the light emitting element 51 and the light emitting element 52 toward the stacked medium before being conveyed by the paper feed roller 21. The light emitting element 51 emits light having a large incident angle (an angle formed by the direction in which light enters and the normal of the surface at the point where the light enters) toward the medium. Light having a small incident angle is emitted from the light emitting element 52 toward the medium.

  The light incident on the medium excites the fluorescent whitening agent contained in the medium. The fluorescent whitening agent is for increasing the whiteness by adding blue to the yellowish state of the medium by absorbing the ultraviolet rays contained in natural light and fluorescent lamps and emitting blue visible light. When the optical brightener is contained in the medium, the yellowish state of the medium is imparted with a bluish color that is a complementary color of yellow, thereby enhancing the achromatic white. The fluorescent whitening agent is, for example, a substance that absorbs ultraviolet rays at a maximum absorption wavelength of 375 nm and emits visible light at a maximum emission wavelength of 435 nm.

  Light emitted from the fluorescent whitening agent excited by the light emitted from the light emitting element 51 and the light emitting element 52 is detected by the light receiving element 53.

<Relationship between the incident angle of light and the amount of light emitted by the excited fluorescent brightener>
Next, the relationship between the incident angle of light and the amount of light emitted by the excited fluorescent brightener will be described with reference to FIGS. 6A and 6B. FIG. 6A is an explanatory diagram for explaining the amount of light emitted by the excited fluorescent whitening agent when the incident angle of light is large. FIG. 6B is an explanatory diagram for explaining the amount of light emitted by the excited fluorescent brightener when the incident angle of light is small. 6A and 6B, ◯ represents that the fluorescent whitening agent has been excited, and x represents that the fluorescent whitening agent has not been excited.

  As shown in FIG. 6A, when the incident angle of light is large, the light is irradiated only on the surface of the medium. Thus, only the fluorescent brightener present on the surface of the medium is excited. On the other hand, as shown in FIG. 6B, when the incident angle of light is small, the light reaches the inside of the medium. Therefore, the fluorescent brightener present inside the medium is also excited. As described above, the amount of the fluorescent brightening agent to be excited is larger when the incident angle of light is smaller than when the incident angle of light is large. Therefore, the output of the light receiving element is larger when the incident angle of light is smaller than when the incident angle of light is large. Therefore, in order to distinguish the medium based on the amount of the optical brightener contained in the medium, it is preferable that the incident angle of light is small when the medium is thick.

<Problem when light with a small incident angle is irradiated while thin media are stacked>
However, when light with a small incident angle is irradiated in a state where thin media are stacked, it is impossible to accurately determine the amount of the fluorescent whitening agent contained in the medium positioned at the top There is. Such a case will be described with reference to FIGS. 7A, 7B, 8A, and 8B. In FIG. 7A and FIG. 7B, a medium in which “O” and “X” are not written is a medium that does not contain a fluorescent brightening agent.

  Note that in this embodiment mode, a thick medium is a medium in which light irradiated by the light emitting element almost perpendicularly to the medium does not pass through the medium. A thin medium is a medium through which light irradiated by the light emitting element substantially perpendicularly to the medium passes through the medium.

  As shown in FIG. 7A, when a medium that does not contain a fluorescent whitening agent is located at the top and a medium that contains a fluorescent whitening agent is located therebelow, light with a small incident angle is irradiated. Then, the light reaches the medium located below. Then, the fluorescent whitening agent contained in the medium located below is excited, and light is emitted from the fluorescent whitening agent. The light receiving element detects light emitted from the fluorescent brightening agent. In this case, there is a possibility that the medium positioned at the top is erroneously determined as containing the fluorescent brightening agent.

  On the other hand, as shown in FIG. 7B, when a medium containing no optical brightener is positioned at the top and a medium containing the optical brightener is positioned therebelow, light having a large incident angle is emitted. When irradiated, the light is only irradiated to the medium located at the top. In this case, the light receiving element does not detect light. Therefore, it is accurately determined that the medium located at the top does not contain the fluorescent brightener.

  In addition, as shown in FIG. 8A, when a medium containing a fluorescent brightening agent is positioned at the top and a medium containing a fluorescent brightening agent is positioned therebelow, light with a small incident angle is irradiated. Then, the light reaches the medium located below. Then, the fluorescent whitening agent contained in the medium located below is excited, and light is emitted from the fluorescent whitening agent. And a light receiving element detects the light emitted from the fluorescent whitening agent contained in the medium located in the lower part with the light emitted from the fluorescent whitening agent contained in the medium located in the top. In this case, it is erroneously determined that the amount of the fluorescent brightening agent contained in the medium located at the top is larger than the original amount.

  On the other hand, as shown in FIG. 8B, light having a large incident angle is irradiated when a medium containing a fluorescent whitening agent is positioned at the top and a medium containing a fluorescent whitening agent is positioned therebelow. Then, the light is irradiated only to the medium located at the top. In this case, the light receiving element detects only the light emitted from the fluorescent brightener contained in the medium positioned at the top. Accordingly, the amount of the fluorescent brightener contained in the medium located at the top is accurately determined.

  Thus, in order to distinguish the medium based on the amount of the optical brightener contained in the medium, it is preferable that the incident angle of light is small when the medium is thick, and when the thin medium is laminated. A larger incident angle of light is preferable.

<About the media identification method>
Next, a method for determining the type of medium will be described with reference to FIG. 9, FIG. 10, and FIG. FIG. 9 is an explanatory diagram for explaining a method of determining the type of medium. FIG. 10 is experimental data showing output values when light emitted from fluorescent whitening agents contained in various media is detected when various media are irradiated with light having a large incident angle. FIG. 11 is experimental data showing output values when light emitted from fluorescent brighteners contained in various media is detected when various media are irradiated with light having a small incident angle.

In step S101, the controller 60 determines whether a thin medium (for example, plain paper) has been selected as the medium to be printed. The case where the thin medium is selected is a case where the user selects the thin medium on the user interface shown in FIG. 2 and sets the stacked thin medium on the paper feed tray. The case where the thick medium is selected is a case where the user selects the thick medium on the user interface shown in FIG. 2 and sets the stacked thick medium on the paper feed tray.
If the controller 60 determines in step S101 that the medium to be printed is thin, the process proceeds to step S102.

  In step S102, the controller 60 irradiates the medium from the light emitting element 51 with light having a large incident angle. The reason for irradiating the medium with light having a large incident angle from the light emitting element 51 is to accurately determine the type of the medium positioned on the top of the stacked thin media.

  In step S103, the controller 60 determines whether or not the output of the light receiving element 53 is greater than 100 mV. If the controller 60 determines in step S103 that the output of the light receiving element 53 is greater than 100 mV, the process proceeds to step S104. In the steps so far, the thin medium candidates are plain paper (with fluorescent whitening agent), plain paper (without fluorescent whitening agent), and coated paper (thin paper) shown in FIG.

  In step S104, the controller 60 determines whether or not the output of the light receiving element 53 is greater than 500 mV. The case where the output of the light receiving element 53 is larger than 500 mV is a case where the optical brightener is contained in the medium. If the controller 60 determines in step S104 that the output of the light receiving element 53 is greater than 500 mV, the process proceeds to step S105. In the steps so far, the candidates for the thin medium are the plain paper (with the fluorescent whitening agent) and the coated paper (thin paper) shown in FIG.

  In step S105, the controller 60 determines whether or not the output of the light receiving element 53 is greater than 750 mV. If the controller 60 determines in step S105 that the output of the light receiving element 53 is greater than 750 mV, the process proceeds to step S106. In step S106, the controller 60 determines that the medium is plain paper (with a fluorescent brightener).

If the controller 60 determines in step S105 that the output of the light receiving element 53 is smaller than 750 mV, the process proceeds to step S107. In step S107, the controller 60 determines that the medium is coated paper (thin paper).
If the controller 60 determines in step S104 that the output of the light receiving element 53 is smaller than 500 mV, the process proceeds to step S108. In step S108, the controller 60 determines that the medium is plain paper (no optical brightener).
If the controller 60 determines in step S103 that the output of the light receiving element 53 is smaller than 100 mV, the process proceeds to step S109. In step S109, the controller 60 determines that the medium is OHP.

  As described above, in the processing from step S102 to step S109, the type of the thin medium is determined.

If the controller 60 determines in step S101 that the medium to be printed is thick, the process proceeds to step S110.
In step S110, the controller 60 irradiates the medium from the light emitting element 52 with light having a small incident angle. The reason for irradiating the medium with light having a small incident angle from the light emitting element 52 is that the fluorescent whitening agent contained in the thick medium is excited by causing the light to reach the inside of the thick medium, and the fluorescence contained in the medium. This is because the type of the medium is more accurately determined based on the amount of the brightener. Also, in the case of a thick medium, unlike the case of a thin medium, even if light with a small incident angle is irradiated, the light passes through the medium and excites the fluorescent whitening agent contained in the medium located below the medium. There is no.

In step S111, the controller 60 determines whether or not the output of the light receiving element 53 is larger than 600 mV. When the output of the light receiving element 53 is larger than 600 mV, the candidate medium contains a fluorescent brightening agent. If the controller 60 determines in step S111 that the output of the light receiving element 53 is greater than 600 mV, the process proceeds to step S112.
In step S112, the controller 60 determines that the medium is either coated paper (thick paper) or glossy paper (with fluorescent brightener).
If the controller 60 determines in step S111 that the output of the light receiving element 53 is smaller than 600 mV, the process proceeds to step S113. In step S113, the controller 60 determines that the medium is glossy paper (no optical brightener).

  As described above, the type of the thick medium is determined in the processing from step S110 to step S113.

=== Other Embodiments ===
Although a printer has been described as an example of a printing apparatus that can use the medium discrimination device according to the present invention, the above embodiment is for facilitating the understanding of the present invention. It is not intended to limit the invention. The present invention can be changed or improved without departing from the gist thereof, and needless to say, the present invention includes equivalents thereof.

  In the present embodiment, part or all of the configuration realized by hardware may be replaced by software, and conversely, part of the configuration realized by software may be replaced by hardware.

  In the medium discrimination process according to the present embodiment, the user selects a thin medium or a thick medium on the user interface shown in FIG. Set. And the controller 60 discriminate | determined the kind of a thin medium or a thick medium, respectively. For example, it is assumed that the user selects a thin medium (plain paper) on the user interface shown in FIG. 2 and sets the stacked thin medium in the paper feed tray. Then, it is assumed that the thin medium is coated paper (thin paper) as a result of determining the type of the thin medium by the medium determination processing. In this case, the controller 60 can display a warning screen on the user interface.

  Further, in the medium determination process of the present embodiment, the type of medium is determined in a state where the media are stacked. This is because stacked media are set in the paper feed tray. However, when only one medium is set in the paper feed tray, the controller 60 can determine the type of the medium by irradiating light with a small incident angle from the light emitting element 52 toward the medium. it can. This is because, in a state where only one medium is set, the light receiving element is not affected by light other than light emitted from the fluorescent whitening agent included in the set medium.

  In the present embodiment, the light emitting element 51 and the light emitting element 52 are irradiated with ultraviolet rays. However, the light emitting element 51 and the light emitting element 52 may be irradiated with other light including ultraviolet rays.

  Further, in the present embodiment, the light emitting element 51 is provided at a position where the incident angle of light applied to the medium is increased, and the light emitting element 52 is provided at a position where the incident angle of light applied to the medium is reduced. . However, the light-emitting element can be provided so as to be movable in accordance with the incident angle of light applied to the medium. By doing so, light with a small incident angle and light with a large incident angle can be irradiated from one light emitting element toward the medium.

  Further, in the medium determination process of the present embodiment, the user has selected either a thin medium or a thick medium, but the controller 60 determines whether the selected medium is a thin medium or a thick medium. You may make it discriminate | determine.

  In the present embodiment, the controller 60 discriminates the type of the medium based on the amount of the fluorescent brightener contained in the medium. However, the controller 60 can combine a medium determination method based on other characteristics of the medium with the medium determination method of the present embodiment. For example, the controller 60 can determine the type of the medium more finely based on the glossiness of the medium and the amount of the fluorescent brightening agent contained in the medium.

  The controller 60 can determine the glossiness of the medium by irradiating the medium with infrared rays and receiving the infrared rays reflected from the medium. In the medium determination process shown in FIG. 9, the controller 60 determines in step S112 that the medium to be printed is either thick coated paper or glossy paper containing a fluorescent brightening agent. In this case, the controller 60 cannot specify one type of medium to be printed in step S112.

  However, the controller 60 determines whether the medium to be printed is thick coated paper or glossy paper containing a fluorescent brightening agent by determining the glossiness of the medium after the process of step S112. It becomes possible to do.

  As described above, the controller 60 determines the type of the medium based on the result of detecting the light emitted from the fluorescent brightener contained in the medium and the result of detecting the infrared light reflected from the medium. Can do. Therefore, the controller 60 can determine the type of the medium more finely by combining the medium determination method based on other characteristics (glossiness) of the medium with the medium determination method of the present embodiment.

It is explanatory drawing which showed the external appearance structure of the printing system. 3 is an explanatory diagram of a user interface of a printer driver. FIG. 1 is a block diagram of an overall configuration of a printer. 1 is a cross-sectional view of the overall configuration of a printer. It is explanatory drawing for demonstrating the light emitting element and light receiving element which comprise a medium discrimination | determination apparatus. FIG. 6A is an explanatory diagram for explaining the amount of light emitted by the excited fluorescent whitening agent when the incident angle of light is large. FIG. 6B is an explanatory diagram for explaining the amount of light emitted by the excited fluorescent brightener when the incident angle of light is small. FIG. 7A illustrates a state in which light having a small incident angle is irradiated when a medium containing no fluorescent brightening agent is positioned at the top and a medium including a fluorescent brightening agent is positioned therebelow. It is explanatory drawing to do. FIG. 7B illustrates a state in which light having a large incident angle is irradiated when a medium containing no fluorescent brightening agent is positioned at the top and a medium including the fluorescent brightening agent is positioned therebelow. It is explanatory drawing to do. FIG. 8A illustrates a state in which light having a small incident angle is irradiated when a medium containing a fluorescent whitening agent is positioned at the top and a medium including a fluorescent whitening agent is positioned therebelow. It is explanatory drawing. FIG. 8B illustrates a state in which light having a large incident angle is irradiated when a medium containing a fluorescent brightening agent is positioned at the top and a medium including a fluorescent brightening agent is positioned therebelow. It is explanatory drawing. It is explanatory drawing for demonstrating the method to discriminate | determine the kind of medium. It is experimental data which shows the output value when detecting the light emitted from the fluorescent whitening agent contained in various media when irradiating light with a large incident angle to various media. FIG. 11 is experimental data showing output values when light emitted from fluorescent brighteners contained in various media is detected when various media are irradiated with light having a small incident angle.

Explanation of symbols

1 printer,
20 transport unit, 21 paper feed roller, 22 transport motor, 23 transport roller,
24 platen, 25 paper discharge roller,
30 Carriage unit, 31 Carriage,
40 head units, 41 heads,
50 sensor groups, 51 light emitting elements, 52 light emitting elements, 53 light receiving elements,
54 Rotary encoder, 55 Paper detection sensor,
60 controller, 61 interface unit, 62 CPU, 63 memory,
64 unit control circuit,
1000 printing system, 1100 computer, 1200 display device,
1300 input device, 1300A keyboard, 1300B mouse,
1400 recording / reproducing apparatus, 1400A flexible disk drive apparatus,
1400B CD-ROM drive device,
S Medium

Claims (9)

A light source that irradiates the medium with light;
A detection unit that detects light emitted from the fluorescent agent when the medium containing the fluorescent agent is irradiated with light from the light source; and
A medium determination device that determines the type of the medium based on the detection result of the detection unit,
The medium discrimination device characterized in that, based on the thickness of the medium, an incident angle at which light emitted from the light source enters the medium is changed. The medium discrimination device according to claim 1,
The light source irradiates light to the stacked medium. A medium determination device. In the medium discrimination device according to claim 1 or 2,
The light source irradiates the medium with ultraviolet rays. In the medium discriminating device according to any one of claims 1 to 3,
When irradiating light from the light source to a medium having a different thickness, the incident angle of light irradiated to the thicker medium is smaller than the incident angle of light irradiated to the thinner medium. Media discrimination device. The medium determination device according to claim 1, wherein:
The medium determination device, wherein the light source is movable so that the incident angle changes. The medium determination device according to claim 1, wherein:
With multiple light sources,
Each said light source is each provided in the position from which the said incident angle differs. The medium discrimination | determination apparatus characterized by the above-mentioned. The medium discrimination device according to any one of claims 1 to 6,
An infrared light source for irradiating the medium with infrared light;
A reflected light detection unit for detecting infrared light reflected from the medium different from the detection unit;
Further comprising
A medium discrimination device that discriminates the type of the medium based on a detection result of the detection unit and a detection result of the reflected light detection unit. A light source that irradiates the medium with light;
A detection unit that detects light emitted from the fluorescent agent when the medium containing the fluorescent agent is irradiated with light from the light source; and
A medium determination device that determines the type of the medium based on the detection result of the detection unit,
Based on the thickness of the medium, the incident angle at which the light emitted from the light source is incident on the medium is changed,
The light source irradiates the stacked medium with light,
The light source irradiates the medium with ultraviolet rays,
When the medium having different thickness is irradiated with light from the light source, the incident angle of the light irradiated to the thicker medium is smaller than the incident angle of the light irradiated to the thinner medium,
With multiple light sources,
Each said light source is each provided in the position from which the said incident angle differs. The medium discrimination | determination apparatus characterized by the above-mentioned. A medium determining method for determining the type of the medium based on a result of irradiating a medium containing a fluorescent agent with light from a light source that irradiates light to the medium and detecting light emitted from the fluorescent agent,
A medium determination method, wherein an incident angle at which light emitted from the light source enters the medium is changed based on a thickness of the medium.

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