Patent Description:
When printing is performed with a printing apparatus, it is known that printing is performed by using controlled parameters appropriate for a type of printing medium. <CIT> describes that, in order to perform printing by using appropriate controlled parameters, a plurality of characteristic values of a printing medium to be printed is measured and the type of the printing medium is identified by making a comparison with reference values. <CIT> discloses a recording apparatus capable of changing the kind of sheet on which printing occurs, includes a discrimination circuit for discriminating the kind of sheet on which printing is to occur specified in input data, and a memory for storing data representing the kind of sheet set in the apparatus. A control circuit then controls the apparatus based on outputs from the discrimination circuit and the memory.

However, errors in a sensor that measures the characteristic values of a printing medium, individual differences among printing media, differences in measurement environment, and the like, influence measured values, so the type of printing medium may not be identified with sufficient accuracy when references prepared in advance are used.

The present invention provides accurate identification of the type of a printing medium by increasing the opportunity to improve the accuracy of determining the type of a printing medium based on measurement results.

The present invention in its first aspect provides an information processing apparatus as specified in claims <NUM> to <NUM>.

The present invention in its second aspect provides an information processing method as specified in claims <NUM> to <NUM>.

The present invention in its third aspect provides a program as specified in claim <NUM> and <NUM>.

Each of the embodiments of the present invention described below can be implemented solely or as a combination of a plurality of the embodiments. Also, features from different embodiments can be combined where necessary or where the combination of elements or features from individual embodiments in a single embodiment is beneficial.

<FIG> are perspective views showing the configuration of a printing apparatus <NUM> equipped with casters and a basket for sheet discharge. <FIG> shows the overall outer appearance. <FIG> shows an internal structure with a top cover open. The printing apparatus <NUM> in the present embodiment prints by applying ink droplets as a printing material onto a printing medium with an ink jet printing method. A printing medium is conveyed in a conveyance direction set to a Y direction. An ink jet printing apparatus including a so-called serial printing head will be described. With the serial printing head, a carriage <NUM> on which a printing head <NUM> is mounted prints while reciprocally moving in an X direction that intersects with the Y direction. Alternatively, an ink jet printing apparatus including a so-called line printing head may be used. With the line printing head, an array of nozzles is provided over a print swath in a direction to convey a printing medium. Alternatively, a multifunctional peripheral apparatus (MFP) that integrates not only a printing function but also a scanning function, a facsimile function, a sending function, or the like, may be used. Alternatively, an electrophotographic printing apparatus that uses powder toner as a printing material may be used. In the present embodiment, the function of an information processing apparatus for executing a process of determining a printing medium to be used (described later) is equipped for the printing apparatus <NUM>.

The printing apparatus <NUM> has an input/output unit <NUM> at its top. The input/output unit <NUM> is an operation panel and shows an ink level and candidates for a type of printing medium on a display. When a user operates keys on the input/output unit <NUM>, the user is able to select a type of printing medium or configure the settings for printing.

The carriage <NUM> includes an optical sensor <NUM> (<FIG>) and the printing head <NUM>. The printing head <NUM> has a discharge port face at which discharge ports for discharging ink are provided. The carriage <NUM> is configured to be reciprocally movable in the X direction (carriage moving direction) along a shaft <NUM> via a carriage belt <NUM> by being driven by a carriage motor <NUM> (<FIG>). In the present embodiment, the printing apparatus <NUM> is able to acquire a diffused reflection characteristic value or a specular reflection characteristic value and measure a distance between the carriage <NUM> and a printing medium <NUM> with the use of the optical sensor <NUM>.

The printing medium <NUM>, such as rolled paper, is conveyed on a platen <NUM> in the Y direction by a conveyor roller (not shown). While the carriage <NUM> is moving in the X direction above the printing medium <NUM> conveyed on the platen <NUM> by the conveyor roller, ink droplets are discharged from the printing head <NUM>. Thus, printing operation is performed. As the carriage <NUM> moves to an end of printing area on the printing medium <NUM>, the conveyor roller conveys the printing medium <NUM> by a certain amount and moves the carriage <NUM> to a position at which the printing head <NUM> is able to print on an area to be subjected to the next scanning and printing. Through a repetition of the above-described operations, an image is printed.

<FIG> is a view that shows the configuration of the carriage <NUM>. The carriage <NUM> includes a translator <NUM> and a head holder <NUM>. The head holder <NUM> holds the printing head <NUM> and the optical sensor <NUM> that is a reflection sensor. As shown in <FIG>, the optical sensor <NUM> is arranged such that a bottom face is equal to or higher in level than the bottom face of the printing head <NUM>.

<FIG> is a schematic cross-sectional view showing the configuration of the optical sensor <NUM>. The optical sensor <NUM> includes a first LED <NUM>, a second LED <NUM>, a third LED <NUM>, a first photodiode <NUM>, a second photodiode <NUM>, and a third photodiode <NUM> as optical elements. The first LED <NUM> is a light source having an angle of irradiation of a normal line (<NUM>°) to the surface (measurement surface) of the printing medium <NUM>. The first photodiode <NUM> receives light irradiated from the first LED <NUM> and reflected from the printing medium <NUM> at an angle of <NUM>° with respect to the Z direction. In other words, an optical system that detects a so-called diffused reflection component of reflected light from the printing medium <NUM> is formed.

The second LED <NUM> is a light source having an angle of irradiation of <NUM>° to the surface (measurement surface) of the printing medium <NUM> with respect to the Z direction. The first photodiode <NUM> receives light irradiated from the second LED <NUM> and reflected from the printing medium <NUM> at an angle of <NUM>° with respect to the Z direction. In other words, an angle of emitting light and an angle of receiving light are equal to each other, and an optical system that detects a so-called specular reflection component of reflected light from the printing medium <NUM> is formed.

The third LED <NUM> is a light source having an angle of irradiation of a normal line (<NUM>°) to the surface (measurement surface) of the printing medium <NUM>. The second photodiode <NUM> and the third photodiode <NUM> each receive light irradiated from the third LED <NUM> and reflected from the printing medium <NUM>. The second photodiode <NUM> and the third photodiode <NUM> measure a distance between the optical sensor <NUM> and the printing medium <NUM> because the amount of light received changes with a distance between the optical sensor <NUM> and the printing medium <NUM>.

In the present embodiment, the optical sensor <NUM> is installed on the carriage <NUM>. An optical sensor may be provided in another mode. For example, an optical sensor may be fixed to the printing apparatus <NUM> or may be a measurement device for measuring a characteristic value, such as a diffused reflection value and a specular reflection value, of a printing medium, separated from the printing apparatus <NUM>, and may be in a mode to send a characteristic value measured by the measurement device to the printing apparatus <NUM>.

<FIG> is a diagram showing the block configuration of a control system of the printing apparatus <NUM>. A ROM <NUM> is a non-volatile memory. For example, a control program for controlling the printing apparatus <NUM> or a program for implementing the operations of the present embodiment are stored in the ROM <NUM>. The operations of the present embodiment are, for example, implemented when the CPU <NUM> reads the program stored in the ROM <NUM> and runs the program by loading the program onto the RAM <NUM>. The RAM <NUM> is also used as a working memory of the CPU <NUM>. The EEPROM <NUM> stores data to be held even when the power of the printing apparatus <NUM> is turned off. At least the CPU <NUM> and the ROM <NUM> implement the function of the information processing apparatus for executing a printing medium determination process (described later). The EEPROM <NUM> stores characteristic values of each of printing media, which are used as predetermined references, and categories of the printing media. Categories are those roughly classified from types of printing media. In the present embodiment, five categories, that is, glossy paper, plain paper, coated paper, photo paper, and special, are set. For example, types of printing media are classified into a glossy paper category when a printing medium is standard glossy paper, and are classified into a plain paper category when a printing medium is premium plain paper. Printing media also include a medium that is not a paper medium; however, in the present embodiment, the word "paper" is used and provided to a user. Characteristic values of printing media may be stored in not a storage medium in the printing apparatus <NUM> but an external memory, such as a ROM of a host computer and a server.

An interface (I/F) circuit <NUM> connects the printing apparatus <NUM> and a network, such as an external LAN. The printing apparatus <NUM> sends or receives various jobs, data, and the like, to or from an apparatus, such as an external host computer, through the I/F circuit <NUM>.

The input/output unit <NUM> includes an input unit and an output unit. The input unit functioning as input means receives an instruction to turn on the power from a user, an instruction to perform printing, and an instruction to set various functions. The output unit functioning as notification means displays various device information, such as power-saving mode, or a settings screen for various functions that the printing apparatus <NUM> is able to execute. In the present embodiment, the input/output unit <NUM> is the operation panel provided in the printing apparatus <NUM>, and the input/output unit <NUM> is connected to a system bus <NUM> via an input/output control circuit <NUM> so as to be able to send or receive data to or from the system bus <NUM>. In the present embodiment, the CPU <NUM> executes control to provide information about the output unit.

Alternatively, the input unit may be a keyboard of an external host computer and may be configured to be able to receive an instruction of a user from the external host computer. The output unit may be a display connected to an LED display, an LCD display, or a host apparatus. Alternatively, when the input/output unit <NUM> is a touch panel, the input/output unit <NUM> is able to receive an instruction from a user with a software key. Alternatively, the input/output unit <NUM> may be a speaker and a microphone, may use input from a user as voice input, and may use information to be provided to a user as voice output.

An information processing apparatus that includes a CPU and a ROM having similar functions to those of the CPU <NUM> and the ROM <NUM> and that is externally connected to the printing apparatus <NUM> may execute a printing medium determination process (described later) and determine a printing medium to be used in the printing apparatus <NUM>.

When a measurement is performed with the optical sensor <NUM>, an LED control circuit <NUM> is driven by the CPU <NUM>, and a predetermined LED in the optical sensor <NUM> is controlled so as to light up. Each of the photodiodes of the optical sensor <NUM> outputs a signal commensurate with received light. The output signal is converted to a digital signal by an A/D conversion circuit <NUM> and is once saved in the RAM <NUM>. Data to be saved is stored in the EEPROM <NUM> when the power of the printing apparatus <NUM> is turned off.

The printing head control circuit <NUM> supplies a drive signal commensurate with printing data to a nozzle drive circuit including a selector and a switch mounted on the printing head <NUM> and controls the printing operation of the printing head <NUM>, such as the driving sequence of nozzles. For example, when data to be printed is sent from the outside to the I/F circuit <NUM>, the data to be printed is once saved in the RAM <NUM>. The printing head control circuit <NUM> drives the printing head <NUM> based on printing data converted from the data to be printed to printing data for printing. After that, an LF (line feed) motor drive circuit <NUM> drives an LF motor <NUM> based on the bandwidth of printing data, and the like, and the conveyor roller connected to the LF motor <NUM> rotates to convey a printing medium. A CR (carriage) motor drive circuit <NUM> causes the carriage <NUM> to scan via the carriage belt <NUM> by driving the CR (carriage) motor <NUM>.

Data that is sent from the I/F circuit <NUM> contains not only data to be printed but also data of details set by a printer driver. Data to be printed can be, for example, received from the outside via the I/F circuit <NUM> and stored in a storage unit or stored in advance in a storage unit, such as a hard disk. The CPU <NUM> reads image data from the storage unit, controls an image processing circuit <NUM>, and converts (binarizing process) the image data into printing data to use the printing head <NUM>. The image processing circuit <NUM>, other than the binarizing process, executes various image processing, color space conversion, HV conversion, gamma correction, and rotation of image.

By identifying the type of the printing medium <NUM> to be printed, parameters such as the maximum amount of ink usage, the level of the printing head <NUM>, a force attracting the printing medium <NUM> to the platen <NUM>, the degree of correction in the amount of conveyance of the printing medium <NUM> are set. Another control parameter that affects the characteristics of the printing medium <NUM> may be used.

In the present embodiment, there are five modes in selecting a type of printing medium. The five modes are a fixed mode, a manual mode, an estimated manual mode, an estimated automatic mode, and a bar code mode. Of these modes, the estimated manual mode and the estimated automatic mode are measurement modes for estimating a type of printing medium from measurement results. The manual mode, the fixed mode, and the bar code mode are designation modes for designating a type of printing medium by a user or determining a type of printing medium through designation of mode without using a measurement result.

In the fixed mode, a type of printing medium set in advance by the user is automatically determined as the type of the printing medium to be printed.

In the manual mode, the categories of printing media are displayed on the input/output unit <NUM>, and the user selects a category and further selects a type of printing medium from the selected category to determine the type of the printing medium to be printed.

In the estimated manual mode, the characteristics of the printing medium <NUM> to be printed are measured with the optical sensor <NUM>, and candidates for the type of the printing medium are displayed on the input/output unit <NUM> based on the measurement results. When the user selects a type of printing medium from the input/output unit <NUM>, the type of the printing medium to be printed is determined.

In the estimated automatic mode, the characteristics of the printing medium <NUM> to be printed are measured with the optical sensor <NUM>, and candidates for the type of printing medium are displayed on the input/output unit <NUM> based on the measurement results. When no operation has been performed by the user for a predetermined time, the top one of the candidates displayed for the type of printing medium is determined as the type of the printing medium to be printed. When a type of printing medium has been selected by the user, the selected type is determined as the type of the printing medium to be printed.

In the bar code mode, information that indicates a type of printing medium is printed in advance on a printing medium as a bar code, and the type of the printing medium to be printed is determined by reading the bar code.

The above five modes can be switched by the user. <FIG> shows a home screen displayed on the input/output unit <NUM>. <FIG> shows a state when "MAIN SETTINGS" is selected from among the items displayed on the home screen. When an item is selected, the selected item is highlighted, and the next screen is displayed. In <FIG>, the item is highlighted such that the background of the item is varied in color from the other items and the frame of the item is widened.

When "MAIN SETTINGS" is selected on the home screen, a main settings screen as shown in <FIG> is displayed. When a button <NUM> displayed in <FIG> is touched, display of the screen can be scrolled downward. When "STOP" is touched, display of <FIG> is switched to display of the home screen of <FIG>. When "PAPER-RELATED SETTINGS" is selected on the main settings screen, "PAPER-RELATED SETTINGS" is highlighted as shown in <FIG>, and a paper-related settings screen as shown in <FIG> is displayed. <FIG> shows a state when "PAPER TYPE SELECTING METHOD" is selected on the settings screen. On the paper-related settings screen, items for setting printing medium information in the printing apparatus <NUM> are displayed. The items include, for example, an item for setting the level of the printing head <NUM> at the time of printing and an item for setting a cut speed at the time of cutting rolled paper. When "PAPER TYPE SELECTING METHOD" is selected on the paper-related settings screen of <FIG>, a paper type selecting method settings screen as shown in <FIG> is displayed. The user is able to set the above-described mode for selecting a type of printing medium on this screen. When "AUTOMATICALLY SELECT FROM ESTIMATED RESULTS" shown in <FIG> is selected, the estimated automatic mode is executed. When "MANUALLY SELECT FROM ESTIMATED RESULTS" is selected, the estimated manual mode is executed. Common Flow among Modes.

<FIG> is a flowchart showing a printing medium determination process of determining a type of a printing medium <NUM> to be printed. The printing medium determination process is a process that is executed after a mode in selecting a type of printing medium is set.

In the following printing medium determination process, measured values are obtained as new information for characteristic values of a type of printing medium, selected by a user, and the predetermined characteristic values are changed based on the measured values so as to be brought close to the measured values. Through such learning, characteristic values with which a type of a printing medium can be more accurately selected are obtained.

For the fixed mode, the manual mode, and the bar code mode, when information is displayed on the input/output unit <NUM>, measurement results of the characteristics of a printing medium, measured with the optical sensor <NUM>, are not used. However, in any mode, a measurement of the characteristics of a printing medium with the optical sensor <NUM> and learning based on the measurement are performed. A measurement is performed even in modes other than the modes in which measured values are used, and learning is performed, with the result that characteristic values that can make it possible to accurately identify a type of printing medium are more likely to be obtained. In the present embodiment, the characteristic values of a printing medium are learned in all the modes. Alternatively, for example, learning may be performed only in the bar code mode in which the probability that a correct printing medium is selected is high.

The processes of step S101 to step S107 of <FIG> are implemented, for example, when the CPU <NUM> shown in <FIG> reads the program stored in the ROM <NUM> onto the RAM <NUM> and runs the program. The printing medium determination process may be executed by software on the host apparatus. In the present embodiment, since the input/output unit <NUM> is the operation panel provided in the printing apparatus <NUM>, candidates for a printing medium are informed by displaying the names of printing media on the operation panel. The input/output unit <NUM> may be a combination of the host apparatus and the display connected to the host apparatus. When the input/output unit <NUM> is a speaker that has a microphone function and that is able to input or output voice, candidates for a printing medium are informed through the speaker, and a printing medium is selected by a user inputting the name of the printing medium or an associated reference sign by voice to the microphone.

As the CPU <NUM> receives an instruction to start sheet feed from a user through the operation panel that is the input/output unit <NUM>, the CPU <NUM> executes a process of feeding the printing medium <NUM>. <FIG> is an example of display on the operation panel to wait for input of an instruction to start the sheet feed process. The operation panel is a touch panel with which a user is able to make touch input. When "YES" is touched, sheet feed is started.

When "YES" is selected in <FIG> and sheet feed is started, the printing medium <NUM> is conveyed by the conveyor roller to a position where the optical sensor <NUM> is able to detect the printing medium <NUM> on the platen <NUM>. After the printing medium <NUM> is conveyed, the carriage <NUM> moves in the X direction above the printing medium <NUM>, and the diffused reflection value, specular reflection value, and thickness (hereinafter, paper thickness) of the printing medium <NUM> are acquired with the optical sensor <NUM> (step S101). A diffused reflection value corresponds to the whiteness of a printing medium. A specular reflection value corresponds to the glossiness of a printing medium. The printing medium determination process may be executed by using the width of a printing medium in the X direction as one of the characteristics of the printing medium. A position where the characteristics of a printing medium are measured may be one, or an average of measurement results at multiple points may be used. A measurement of the characteristics may be performed in a state where the optical sensor <NUM> is stopped or may be performed while the optical sensor <NUM> is being moved. Measured values are once stored in a memory such as the RAM <NUM>.

Subsequently, the CPU <NUM> checks the mode in determining the set printing medium in step S102. The mode is stored in the ROM <NUM>. The CPU <NUM> executes a process appropriate for the set mode. The process proceeds to step S103 in the estimated manual mode. The process proceeds to step S104 in the estimated automatic mode. The process proceeds to step S105 in the manual mode. The process proceeds to step S106 in the fixed mode. The process proceeds to step S107 in the bar code mode. A type of a printing medium to be printed is determined in step S103 to step S107, and the printing medium determination process is ended.

Hereinafter, a process appropriate for each of the modes in step S103 to step S107 will be described.

In the estimated manual mode, measured values are obtained as new information for characteristic values of a type of printing medium, selected by a user, and the predetermined characteristic values are changed based on the measured values so as to be brought close to the measured values. Through such learning, characteristic values with which a type of a printing medium can be more accurately selected are obtained.

<FIG> is a flowchart showing the estimated manual mode of step S103.

In step S201, the CPU <NUM> reads out the measured values acquired in step S101 of <FIG> from the memory, compares the measured values with the predetermined characteristic values of each printing medium, stored in the EEPROM <NUM>, and extracts candidates for the type of printing medium. <FIG> is a flowchart of a process of extracting a type of printing medium in step S201.

Types of printing media of which a degree to which the characteristic values fall under the characteristics indicated by the measured values is higher than a predetermined degree are extracted. Details will be described below. <FIG> shows the characteristic values of each of the types of printing media, stored in the EEPROM <NUM>. The characteristic values = T<NUM> when the characteristic values are initial values at the present. These values are set for reference values, and the type of the printing medium is identified by comparing the measured values with the reference values. The ranges of the reference values are defined as extraction ranges. Diffused reflection values and specular reflection values are values obtained by converting an output voltage from analog to digital with <NUM> bits. The output voltage is a voltage that the optical sensor <NUM> outputs upon receiving light. Each extraction range is a range from a minimum value (min value) to a maximum value (max value) with a center set to a middle value of each of characteristic values of a printing medium.

In step S701, a type of printing medium of which the acquired paper thickness falls within the extraction range of paper thickness, stored in the storage unit (EEPROM) <NUM>, is extracted. In the present embodiment, the extraction range of paper thickness is ±<NUM> from the central value.

It is determined whether there is any type of printing medium extracted (step S702).

When no type of printing medium is extracted, information indicating that there is no extracted type of printing medium is stored in the RAM <NUM>, and the printing medium extraction process is ended.

When there is a type of printing medium extracted in step S702, a type of printing medium of which the acquired diffused reflection value falls within the extraction range of diffused reflection value, stored in the storage unit (EEPROM) <NUM>, is extracted (step S703). As shown in <FIG>, the extraction range of diffused reflection value is a range of ±<NUM> from the central value. Here, it is determined whether there is a type of printing medium extracted (step S704). When there is no applicable type of printing medium, information indicating that there is no extracted type of printing medium is stored in the RAM <NUM>, and the printing medium extraction process is ended.

When there is a type of printing medium extracted in step S704, a type of printing medium of which the acquired specular reflection value falls within the extraction range of specular reflection value, stored in the storage unit (EEPROM) <NUM>, is extracted (step S705). As shown in <FIG>, the extraction range of specular reflection value is a range of ±<NUM> from the central value. Here, it is determined whether there is a type of printing medium extracted (step S706). When there is no applicable type of printing medium, information indicating that there is no extracted type of printing medium is stored in the RAM <NUM>, and the printing medium extraction process is ended.

When there is a type of printing medium extracted in step S706, information indicating that the extracted type of printing medium is stored in the RAM <NUM>, and the printing medium extraction process is ended.

When the printing medium extraction process is ended in step S201, it is determined in step S202 whether there is any extracted printing medium. The determination is performed by the CPU <NUM> reading out the information stored in the RAM <NUM> in the printing medium extraction process of <FIG>.

When there is a type of printing medium extracted in step S202, the type of printing medium is assigned with a priority in order of closeness of the characteristic values of an extracted type of printing medium to the measured values (step S203). A method of determining the order of display will be described in detail later.

As shown in <FIG>, the names of the types of printing media are displayed from the top in descending order of priority determined in step S203 (step S204).

<FIG> shows the names of printing media in descending order of priority with reference numerals <NUM> to <NUM> prefixed to the names of printing media. Selection of a type of printing medium is made by touching any one of the names of printing media displayed. Here, the priority of standard half-glossy paper to which number <NUM> is assigned is the highest. Codes may be any codes as long as the codes can indicate the level of priority, and may be codes other than numerals. A display method is not limited thereto and may be any method as long as a user can recognize the order of priority.

In <FIG>, candidates for a printing medium can be displayed up to three from the top; however, since the number of the extracted types of printing media is two, only two printing media are displayed in <FIG>. A user is informed that there is no third candidate by displaying "NO AVAILABLE CHOICE" in the third field in light color (or dark color) so as to be less attractive than the names of the above-described two printing media. For example, when the background color of the operation panel is black, two printing media are displayed in white color and the text "NO AVAILABLE CHOICE" is displayed in gray color lower in brightness than white color. Categories of paper are displayed below the text "NO AVAILABLE CHOICE". In this way, when a printing medium that a user desires is not included in printing media displayed on the input/output unit <NUM>, an individual printing medium is allowed to be selected in order to select a printing medium of another type. In the present embodiment, the category to which a type of printing medium in the first place belongs is displayed at the top. By displaying categories having close characteristics at higher levels to make it easy to select those categories, even when a printing medium that a user desires is not included in candidates for a printing medium, time and effort that take until the category of a desired printing medium is selected can be reduced.

<FIG> show methods of displaying candidates for a type of printing medium on the input/output unit <NUM> in other modes. As shown in <FIG>, when not all the extracted candidates for a type of printing medium can be displayed on the operation panel, the input/output unit <NUM> may be configured such that a lower-level candidate can be displayed through scroll operation, or the like. Alternatively, candidates do not need to be displayed in order from higher level as long as a user can recognize the order of priority. The name of the top printing medium may be displayed at the center of the operation panel. Alternatively, as shown in <FIG>, the level of priority may be indicated by increasing the size of characters representing the name of a printing medium having a higher level of priority or displaying the characters in boldface. Categories are displayed below the text "PAPER CATEGORY"; however, categories may be displayed without any text meaning "PAPER CATEGORY". Alternatively, not categories but types of printing media other than candidates for a printing medium may be displayed below the candidates.

Alternatively, as shown in <FIG>, only a printing medium having a priority in the first place may be displayed. When a user desires to select another one of extracted printing media, the user can select a portion of the item of the printing medium displayed as standard plain paper in <FIG>. A display method may be configured such that, when the selection is input, the screen appears as shown in <FIG> and another printing medium can be selected.

When it is determined in step S202 that there is no extracted type of printing medium, categories are displayed on the operation panel as shown in <FIG> (step S205). When a category selected by a user is input, the types of printing media in the category are displayed as shown in <FIG>. Then, of the types of printing media displayed, the input of the selected type of printing medium is received. The input is made by touching the name of the printing medium displayed. <FIG> shows "ALL" at the bottom in addition to the categories of printing media. When "ALL" is selected, all the printing media are displayed in a predetermined order. Printing media may be displayed in recent order, that is, in order from the latest used printing medium.

When a user selects a type of printing medium on the input/output unit <NUM> in step S206, it is determined in step S207 whether the measured values fall within the learning ranges of the selected printing medium. The learning ranges will be described here. By changing the characteristic values of a type of printing medium, selected by a user, based on measured values, the characteristic values that further increase the accuracy of extraction can be obtained. However, if learning is performed based on a measured value significantly different from a characteristic value set in advance (or changed through a learning process), a wrong value is learned, so a learning range that is the range of a measured value to be learned is set. A learning range is twice as large as an extraction range in the present embodiment. A learning range is a range for changing a characteristic value. When a measured value falls within the learning range of a selected printing medium, the characteristic value is changed based on the measured value. In the present embodiment, a learning range is a range of a predetermined value from the central value of a characteristic value and is a range of a value twice as large as the difference between the central value and the minimum value or the difference between the central value and the maximum value. For example, the extraction range of specular reflection value of standard glossy paper in <FIG> is from <NUM> to <NUM>, that is, ±<NUM> from the central value. Since the learning range takes on a range of ±<NUM> from the central value, that is, twice as large as ±<NUM>, the learning range is from <NUM> to <NUM>. Similarly, a diffused reflection value and a paper thickness each also take on a range twice as wide as the extraction range, so the learning range of diffused reflection value of standard glossy paper is from <NUM> to <NUM>, and the learning range of paper thickness is from <NUM> to <NUM>. The learning range is not limited thereto and may take on, for example, the same range as the extraction range or may be set to a learning range that varies among characteristics or types of printing media. When the measured values fall within the learning ranges of the selected type of printing medium, the process proceeds to step S208. In step S208, the characteristic values of the type of printing medium, selected in step S206, are updated with values changed based on the measured values, and the changed values are stored in the EEPROM <NUM>. Thus, the printing medium determination process in the estimated manual mode ends. When the measured values do not fall within the learning ranges, the printing medium determination process in the estimated manual mode is ended without updating the characteristic values of the selected type of printing medium. An update of characteristic values will be described in detail later.

When the printing medium determination process ends and a printing preparation completes, the CPU <NUM> is in a state of waiting for a printing job from a user, and, upon receiving a printing job, starts printing. The CPU <NUM> may be configured to receive a printing job and store the printing job in the RAM <NUM> before the printing preparation completes, and start printing when the printing preparation completes. When the type of printing medium selected and input by a user from the input/output unit <NUM> is different from the type of printing medium in a job sent from a host computer to the printing apparatus <NUM>, the CPU <NUM> may be configured not to update the characteristic values of the printing medium, stored in the EEPROM <NUM>.

In the printing medium extraction process of <FIG>, a type of printing medium having an appropriate paper thickness is extracted in step S701, a type of printing medium having an appropriate diffused reflection value is extracted in step S703, and a type of printing medium having an appropriate specular reflection value is extracted in step S705. The sequence to be extracted is not limited thereto, and, for example, a type of printing medium having an appropriate diffused reflection value may be extracted first.

When the optical sensor <NUM> is provided in a measurement device separated from the printing apparatus <NUM>, the following mode is applicable. The characteristics of a printing medium set in the measurement device are measured first. Then, the acquired measured values are sent to the printing apparatus <NUM>, a printing medium is extracted by the CPU <NUM> of the printing apparatus <NUM>, and a candidate is provided to the input/output unit <NUM>.

A method of determining the order of display of step S203 of the printing medium determination process and an update of the characteristic values of step S208 will be described below by way of a specific example. As shown in <FIG>, the characteristics of the printing medium acquired in step S101 are (diffused reflection value, specular reflection value, paper thickness) = (<NUM>, <NUM>, <NUM>). <FIG> is a table showing determination results of the process of step S201. "APPLICABLE" represents a printing medium of which the measured value falls within the extraction range. "NOT APPLICABLE" represents a printing medium of which the measured value does not fall within the extraction range. A printing medium of which at least one of characteristic values does not fall within the extraction range is not subjected to determination in the next process. This is shown in <FIG> as "NOT DETERMINED".

In step S701, standard glossy paper, standard half-glossy paper, premium glossy paper, and thick glossy paper, which are the types of printing media of which the acquired paper thickness, that is, <NUM>, falls within the extraction range of paper thickness shown in <FIG>, are extracted. Since there are the extracted types of printing media, affirmative determination is made in step S702, and the process proceeds to step S703.

In step S703, from among the printing media extracted in step S701, standard glossy paper, standard half-glossy paper, and thick glossy paper, which are the types of printing media of which the measured diffused reflection value, that is, <NUM>, falls within the extraction range of diffused reflection value shown in <FIG>, are extracted. Since there are the extracted types of printing media, affirmative determination is made in step S704, and the process proceeds to step S705.

In step S705, from among the printing media extracted in step S703, printing media of which the measured specular reflection value falls within the extraction range of specular reflection value shown in <FIG>, are extracted. Here, standard glossy paper, standard half-glossy paper, and thick glossy paper are extracted. Since there are the extracted printing media, affirmative determination is made in step S706, and the process proceeds to step S707. In step S707. information indicating the extracted types of printing media is stored in the RAM <NUM>.

Since there are the extracted types of printing media in step S202, the process proceeds to step S203. In step S203, the printing media are assigned with priorities such that the printing medium of which the characteristic values are closer to the measured values has a higher order of priority. Then, in step S204, the names of the extracted types of printing media are displayed from the top in order from the printing medium having a higher order of priority.

<FIG> and <FIG> are tables for illustrating a method of determining the order in step S203. In the present embodiment, the closeness between the central value and measured value of each characteristic is calculated with the following calculation method. <MAT> A minimum value may be used instead of the maximum value of the characteristic.

For example, when the specular reflection value of standard glossy paper is calculated, |(<NUM> - <NUM>)/(<NUM> - <NUM>)| = <NUM>. The above-described calculation is performed for the types of printing media extracted in step S201, and the values of closeness to the measured values of the characteristics are added. A printing medium having a less total value has characteristic values closer to the measured values. It is determined that a printing medium having a less total value is a type of a higher-level printing medium, and display is performed on the input/output unit <NUM> accordingly. Here, as shown in <FIG>. display is performed in order of standard glossy paper, thick glossy paper, and standard half-glossy paper.

The process of step S206 in the case where standard half-glossy paper that is displayed in the third place is selected by a user in step S207 will be described.

In step S207, it is determined whether the measured values acquired in step S101 fall within the learning ranges of standard half-glossy paper that is the selected type of printing medium. When the measured values fall within the learning ranges of all the characteristics, that is, diffused reflection value, specular reflection value, and paper thickness, it is determined that the measured values fall within the learning ranges of standard half-glossy paper. As shown in <FIG>, the extraction range of specular reflection value of standard half-glossy paper is from <NUM> to <NUM> that is a range of ±<NUM> from the central value (middle) set to <NUM>. As described above, the learning range takes on a range twice as wide as the extraction range from the same central value as the extraction range. The learning range of specular reflection value of standard half-glossy paper is from <NUM> to <NUM> that is a range of ±<NUM> from the central value set to <NUM>. Similarly, the learning range of diffused reflection value of standard half-glossy paper is from <NUM> to <NUM>, and the learning range of paper thickness is from <NUM> to <NUM>. Since all the measured values (diffused reflection value, specular reflection value, paper thickness) = (<NUM>, <NUM>, <NUM>) fall within the above-described learning ranges, the process proceeds to step S208.

In step S208, the characteristic values of the type of printing medium selected are updated based on the measured values. The characteristic values shown in <FIG> are characteristic values before update. <FIG> shows measured values. In the present embodiment, the characteristic values of the type of printing medium are brought close to the measured values by a set percentage. Because the measured values contain measurement errors, the characteristic values may be rather changed such that the differences between the measured values and the characteristic values are reduced in a stepwise manner through learning multiple times, that is, the differences reduce by a set percentage, than the characteristic values are directly replaced with the measured values at a time. One example of that is expressed by a generalized formula as follows. Updated characteristic values (Tn+<NUM>) = (Measured values (R) - Characteristic values (Tn)) × α + Pre-updated characteristic values (Tn)
Here, α is a value that indicates a percentage by which characteristic values are brought close to measured values. When the percentage of reduction in difference is set to <NUM>%, the central value of specular reflection value is as follows. For example, when Tn = T<NUM> (initial value), Ti is found through the first update.

When R = <NUM> and Tn = T<NUM> = <NUM>, T<NUM> is found as follows.

Similarly, the characteristic values of diffused reflection value and paper thickness are updated. The updated results are shown in <FIG>. The fact that the extraction ranges of specular reflection value and diffused reflection value each are ±<NUM> from the central value and the extraction range of paper thickness is ±<NUM> from the central value remains unchanged, and minimum values and maximum values are also updated according to central values. The original characteristic values are overwritten with the updated characteristic values. The updated characteristic values are stored as the characteristic values of standard half-glossy paper in the EEPROM <NUM>, and used in subsequent printing medium determination processes. Thus, the printing medium determination process ends.

In the above-described example, when the characteristic values are updated, the characteristic values are bought close to the measured values by <NUM>%; however, the percentage of reduction in difference is not limited thereto and may be a percentage higher than <NUM>% and lower than or equal to <NUM>%. The percentage of reduction in difference may be set for each type of printing medium or may be set for each characteristic.

In a state where the characteristic values are updated as shown in <FIG>, standard half-glossy paper of which the characteristics of a printing medium are (diffused reflection value, specular reflection value, paper thickness) = (<NUM>, <NUM>, <NUM>) is measured again. The results of priority assignment in order of closeness of the characteristic values to the measured values are shown in <FIG>. As a result of the update of the characteristic values of standard half-glossy paper, standard half-glossy paper is ordered in the first place. Therefore, in step S204, standard half-glossy paper that is the measured printing medium is displayed on the input/output unit <NUM> as the top printing medium, and a user can more easily select the printing medium.

Information is provided in order of closeness of the characteristic values to the measured values; however, another method may be employed. When the usage history information of printing media used is stored in the EEPROM <NUM>, or the like, the history information may be used. For example, the types of printing media extracted through the printing medium extraction process of <FIG> are displayed such that a more recently used printing medium, indicated by the history information, is a printing medium having a higher order of priority and the name of printing medium having a higher order of priority is displayed in order from the top.

Alternatively, as another method of incorporating measured values into characteristic values of a type of printing medium, an average value of last N measured values may be set as each characteristic value. <FIG> are tables for illustrating a method of setting a characteristic value by using last three measured values. Here, the specular reflection value of standard half-glossy paper will be described as an example. <FIG> shows the case where standard half-glossy paper is not selected even once in step S206. In <FIG>, <NUM> that is an initially set value is input as last three values, and the average value is also <NUM>, so the characteristic value is <NUM>. In <FIG>, when standard half-glossy paper is selected, the measured value <NUM> is input as the last measured value. The average value <NUM> at the time when the measured value <NUM> is input is set as the characteristic value that is used subsequently. <FIG> shows the case where standard half-glossy paper is further selected, and <NUM> is input as the last measured value. The average value at this time, that is, <NUM>, is set as the characteristic value to be used subsequently. <FIG> shows the case where standard half-glossy paper is further selected in the state of <FIG>, and <NUM> is input as the last measured value. The average value <NUM> at this time is set as the characteristic value to be used subsequently.

<FIG> is a flowchart showing the estimated automatic mode of step S104.

Similar processes are executed in step S301 to step S303, and step S305 to those of step S201 to step S205 of the estimated manual mode shown in <FIG>.

In step S304, as shown in <FIG>, the names of the types of printing media are displayed from the top in descending order of priority determined in step S303. Together with candidates for a type of printing medium, "AUTOMATICALLY FEED PAPER <NUM>. " is displayed in order to inform that no operation is not required when a type of printing medium of which the order of priority is the highest is selected. In addition, "SELECTABLE FROM LIST" is displayed in order to inform that a type of printing medium other than the type of printing medium of which the order of priority is the highest is selectable.

When the user has not operated the input/output unit <NUM> within a predetermined time in step S306, the type of printing medium of which the priority is the highest of the types of printing media shown in step S304 is determined as the type of the printing medium <NUM> to be printed. The process proceeds to step S310.

When the user has operated the input/output unit <NUM> within the predetermined time in step S306, a type of printing medium, selected by the user, is determined as the type of the printing medium <NUM> to be printed in step S308. When a type of printing medium is selected in step S308, it is determined in step S309 whether the measured values fall within the learning ranges of the selected printing medium. Similar processes are executed in step S309 and step S310 to those of step S207 and step S208 in <FIG>. When the measured values do not fall within the learning ranges, the printing medium determination process in the estimated automatic mode is ended without updating the characteristic values. When the measured values fall within the learning ranges, the process proceeds to step S310.

In step S310, the characteristic values of the selected type of printing medium are updated with changed values based on the measured values, and the changed values are stored in the EEPROM <NUM>. Thus, the printing medium determination process in the estimated automatic mode ends.

<FIG> is a flowchart showing the manual mode of step S105.

In step S401, categories of printing media as shown in <FIG> are displayed on the input/output unit <NUM>. In the present embodiment, the categories are displayed in a predetermined order. Alternatively, when the usage history information of printing media used is stored in the EEPROM <NUM>, or the like, categories to which recently used printing media indicated by the history information belong may be displayed at higher levels. Alternatively, recently used types of printing media, indicated by the history information, may be displayed at higher levels, and categories may be displayed below those types of printing media. Alternatively, not categories but all the types of printing media may be displayed.

When the user selects a category, types of printing media that belong to the category selected by the user as shown in <FIG> are displayed. When the user selects a printing medium from among the displayed types of printing media (step S402), it is determined in step S403 whether the measured values fall within the learning ranges of the selected printing medium. Similar processes are executed in step S403 and step S404 to those of step S207 and step S208 in <FIG>. When the measured values do not fall within the learning ranges, the printing medium determination process in the manual mode is ended without updating the characteristic values. When the measured values fall within the learning ranges, the characteristic values of the type of printing medium, selected in step S402, are updated with values changed based on the measured values in step S404, and the changed values are stored in the EEPROM <NUM>. Thus, the printing medium determination process in the manual mode ends.

When the fixed mode is used, the user selects the fixed mode and sets in advance a type of printing medium to be fixedly used before the printing medium determination process is started. The set type of printing medium is stored in the EEPROM <NUM>. Here, description will be made on the assumption that standard glossy paper is set in advance.

<FIG> is a flowchart showing the fixed mode of step S106.

In step S501, the name of the type of printing medium set in advance is displayed on the input/output unit <NUM> as shown in <FIG>.

When the user has not operated the input/output unit <NUM> within a predetermined time or selects "OK" in <FIG> in step S502, standard glossy paper set in advance is determined as the printing medium <NUM> to be printed, and the process proceeds to step S504.

When "PAPER TYPE" is selected within the predetermined time in step S502, the categories of printing media are displayed as shown in <FIG>, and the user is able to select a type of printing medium not set in advance. When a type of printing medium is selected in step <NUM>, the process proceeds to step S504.

Similar processes are executed in step S504 and step S505 to those of step S207 and step S208 in <FIG>. In step S504, it is determined whether the measured values fall within the learning ranges of the selected printing medium. When the measured values do not fall within the learning ranges, the printing medium determination process in the fixed mode is ended without updating the characteristic values. When the measured values fall within the learning ranges, the characteristic values of the selected type of printing medium are updated with values changed based on the measured values in step S505, and the changed values are stored in the EEPROM <NUM>. Thus, the printing medium determination process in the fixed mode ends.

The bar code mode is mainly used for rolled paper. Hereinafter, description will be made on the assumption that a printing medium to be printed is rolled paper. The printing medium is set in the printing apparatus <NUM> and used when subjected to printing. When the printing medium is removed from the printing apparatus <NUM> or usage of the printing medium is stopped and a different printing medium is used while the bar code mode is designated by the user, a bar code as shown in <FIG> is printed on the printing medium. The type of the printing medium shown in <FIG> is standard plain paper. The bar code is divided into an area A1, an area A2, and an area A3. In the area A1, a pattern for adjusting a reading position is printed. In the area A2, information about the type of printing medium is printed as a bar code. In the area A3, the name of the type of printing medium is printed. Not a bar code but any mode in which a type of printing medium can be identified from information printed on the printing medium may be employed. For example, a QR code (registered trademark), or the like, may be employed.

<FIG> is a flowchart showing the bar code mode of step S107.

In step S601, the bar code printed on the printing medium <NUM> to be printed as shown in <FIG> is read with the optical sensor <NUM>. <FIG> is a schematic view showing a state of being read. While the carriage <NUM> is moving, the first LED of the optical sensor <NUM> is irradiated to the printing medium, and a diffused reflection component is detected with the first photodiode <NUM>. Thus, the bar code is read, and a result of having read bar code is input in CPU401.

In step S602, it is determined whether the bar code is readable. When the bar code is readable, the printing medium <NUM> to be printed is determined to the read type of printing medium in step S604. When the bar code is not readable, the manual mode of <FIG> is executed in step S603.

When the type of printing medium is determined in step S604, similar processes are executed in step S605 and step S606 to those of step S207 and step S208 in <FIG>. In step S605, it is determined whether the measured values fall within the learning ranges of the selected printing medium. When the measured values do not fall within the learning ranges, the printing medium determination process in the bar code mode is ended without updating the characteristic values. When the measured values fall within the learning ranges, the characteristic values of the selected type of printing medium are updated with values changed based on the measured values in step S606, and the changed values are stored in the EEPROM <NUM>. Thus, the printing medium determination process in the bar code mode ends.

As described above, even in a mode in which a type of printing medium to be printed is determined without using measurement results, the characteristics of a printing medium are measured, and the characteristic values of the type of printing medium, determined based on the measured values, are learned. Therefore, as compared to the case where learning is performed in modes in which only measurement results are used, characteristic values that make it possible to further accurately identify a type of printing medium are more likely to be obtained.

Claim 1:
An information processing apparatus comprising:
first acquisition means (<NUM>) configured to acquire a measurement result obtained by measuring a characteristic value of a printing medium (<NUM>) to be printed;
second acquisition means configured to acquire reference characteristic values set in advance for each of types of printing medium to identify a type of the printing medium;
input means (<NUM>, <NUM>, <NUM>) configured to input information indicating a type of the printing medium to be printed; and
control means (<NUM>) configured to control an operation to determine a type of the printing medium to be printed,
change means (<NUM>) configured, based on the measurement result acquired by the first acquisition means, to change a reference characteristic value set in advance for the type of printing medium indicated by the information input by the input means, wherein
the control means is configured to determine the type of printing medium indicated by the information input by the input means as the type of the printing medium to be printed,
the control means is configured to be capable of executing a measurement mode and a designation mode, wherein
in the measurement mode, the type of the printing medium to be printed is determined by using the measurement result acquired by the first acquisition means and the reference characteristic values set in advance and acquired by the second acquisition means, and
in the designation mode, the type of the printing medium to be printed is determined without using the measurement result acquired by the first acquisition means, and
the control means is configured to, even in the designation mode, cause the first acquisition means to acquire the measurement result and cause the change means to change the reference characteristic value set in advance for the type of printing medium indicated by the information input by the input means based on the measurement result acquired by the first acquisition means.