Printing apparatus

Abstract

In a printing device, the transport volume is measured accurately according to the type of recording medium. [Solution] A printing apparatus comprising: a transport unit that transports a recording medium along a transport path; a first measuring unit provided in the transport path that measures the amount of the recording medium transported based on light from the recording medium; a second measuring unit provided in the transport path that measures the amount of the recording medium transported based on the drive amount of the transport unit; a recording unit that records an image on the recording medium; and a control unit that controls recording by the recording unit based on the measurement result of the first measuring unit when the recording medium is of a first type, and controls recording by the recording unit based on the measurement result of the second measuring unit when the recording medium is of a second type different from the first type.

Description

Technical Field

[0001] The present invention relates to a printing apparatus.

Background Art

[0002] In a printing apparatus such as a printer that conveys a loaded recording medium to perform printing, there is known one having a function of measuring the conveyance amount of the recording medium by a sensor.

[0003] Patent Document 1 discloses a technique for measuring the conveyance amount using a sensor in a printing apparatus in which roll paper is loaded as a recording medium. This printing apparatus measures the conveyance amount of the roll paper and corrects the measured value using an encoder sensor and an optical sensor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Since various types of recording media can be loaded in a printing apparatus, it is required to accurately measure the conveyance amount according to the type of the recording medium.

[0006] The present invention is for solving the above problems, and an object thereof is to accurately measure the conveyance amount according to the type of a recording medium in a printing apparatus.

Means for Solving the Problems

[0007] The present invention employs the following configuration. That is, a conveyance unit that conveys a recording medium along a conveyance path, and a first measurement unit that is provided in the conveyance path and measures the conveyance amount of the recording medium based on light from the recording medium A second measuring unit is provided in the transport path and measures the amount of a recording medium transported based on the drive amount of the transport unit, A recording unit that records images onto a recording medium, A printing apparatus comprising: a control unit that controls recording by the recording unit based on the measurement result of the first measuring unit when the recording medium is of a first type; and a control unit that controls recording by the recording unit based on the measurement result of the second measuring unit when the recording medium is of a second type different from the first type. [Effects of the Invention]

[0008] According to the present invention, the amount of material transported can be accurately measured in a printing apparatus according to the type of recording medium. [Brief explanation of the drawing]

[0009] [Figure 1] Block diagram showing the configuration of the printing device [Figure 2A] Perspective view showing the overall configuration of the printing apparatus. [Figure 2B] Perspective view showing the internal structure of the printing device with the top cover removed. [Figure 2C] Perspective view showing the configuration of the sensors in the printing device. [Figure 3] A schematic diagram showing a cross-section of the storage medium transport configuration. [Figure 4] Flowchart showing the process when measuring the amount of material being transported. [Figure 5] Flowchart showing the process during transport volume measurement in Example 1 [Figure 6] Flowchart showing the process during transport volume measurement in Example 2 [Figure 7] A flowchart illustrating the process for measuring the transport volume when performing band adjustment. [Figure 8] UI display screen example [Modes for carrying out the invention]

[0010] Embodiments of this invention will be described below with reference to the drawings. Note that the components, control methods, dimensions, materials, shapes, and arrangements of the components described in these embodiments should be appropriately modified depending on the configuration and various conditions of the device to which the invention is applied. In other words, the scope of this invention is not intended to be limited to the following embodiments.

[0011] In the following description, the recording medium used in the printing device is typically a roll of paper wound into a roll. However, materials other than paper, such as film, may be used as the recording medium. Furthermore, even when using paper, it is not limited to ordinary paper; special papers such as glossy paper may be used. Also, the recording medium is not limited to a roll; cut sheets such as cut paper may be used.

[0012] Here, we consider the challenges of applying various materials to recording media in printing equipment that uses sensors to measure and correct the amount of media being transported. As mentioned above, optical sensors that measure the optical properties of the recording media and encoder sensors that measure the drive amount of the transport mechanism can be used as transport amount sensors, but optical sensors are generally considered to be more accurate. Optical sensors calculate the transport amount by irradiating light such as infrared light, receiving and analyzing the light reflected from the surface of the recording media. However, if the recording media is a special paper such as film paper, the light will pass through, which may reduce the accuracy of the transport amount measurement. Therefore, it is necessary to perform measurements with the transport amount sensor with high accuracy depending on the type of recording media.

[0013] [Embodiment] Figure 1 is a block diagram showing the configuration of the printing apparatus 050 in this embodiment. The printing apparatus 050 includes a CPU 005 that controls the entire apparatus, a printing unit 010 that performs printing, and a sensor unit 011.

[0014] The printing unit 010 includes a recording unit 100, a fixing device 108, an input / output unit 109, and conveying rollers 205 and 206. The recording unit 100 performs printing on a recording medium. The fixing device 108 dries the ink on the printed recording medium. The input / output unit 109 has a user interface such as an LCD, an LED, keys, and a touch panel, accepts inputs such as user operations and instructions, and displays information to the user. The input / output unit 109 can also be considered as an input unit that accepts user inputs and an output unit that outputs information to the user. The conveying rollers 205 and 206 are a conveying unit that conveys the recording medium in the conveying direction F from the mounting unit through the recording unit toward the discharging unit along the conveying path P.

[0015] The sensor unit 011 includes a paper type identification sensor 212 (identification unit), a multi-sensor 213, an optical sensor 214 (first measurement unit), and an encoder sensor 215 (second measurement unit). The paper type identification sensor 212 identifies the paper type from at least one of the surface characteristics and basis weight of the paper. For example, as the paper type identification sensor 212, a sensor combining an ultrasonic sensor and a CIS (Contact Image Sensor) can be used. In this case, the paper type identification sensor 212 estimates the paper type from the basis weight of the paper detected by the ultrasonic sensor and the surface information of the paper detected by the CIS. The multi-sensor 213 estimates the paper type from the thickness of the paper and the illuminance of the reflected light. The optical sensor 214 measures the conveyance amount of the paper from the change in the surface characteristics of the paper (first measurement value). The encoder sensor 215 measures the conveyance amount of the paper from the rotation speed of the conveying roller 205 (second measurement value).

[0016] Here, as shown in FIG. 2C, the optical sensor 214 is arranged on the platen 106, and the encoder sensor 215 is arranged so as to sandwich the conveying roller 205.

[0017] The printing device 050 has a control configuration that operates in conjunction with the CPU 005, which includes ROM 006, RAM 007, NVRAM 008, HDD (hard disk drive) 009, network driver 013, and LAN unit 014. These control configurations function as a control unit. ROM 006 stores the control execution code (program) for the printing device 050. RAM 007 stores print image data as temporary storage during the control execution of the printing device 050. NVRAM 008 is a non-volatile memory that stores various data necessary for the maintenance of the printing device 050 and information related to images for printing. HDD 009 stores image data to be printed by the printing unit 010.

[0018] The network driver 013 and LAN unit 014 constitute an interface for connecting the printer 050 to external devices such as a server. The printer 050 exchanges execution commands and data with the external devices via the network driver 013 and LAN unit 014. For example, image data used for printing by the printer unit 010 is transferred from the external device via the network driver 013 and LAN unit 014.

[0019] Figure 2A is a perspective view showing the entire printing apparatus 050, particularly the external appearance of the recording unit 100. Figure 2B is a perspective view showing the recording unit 100 with its upper cover 110 open, revealing its internal structure. Figure 2C is a magnified perspective view of the area around the platen 106 of the recording unit 100, illustrating the sensor structure.

[0020] The recording unit 100 of this embodiment is an inkjet recording device that performs recording by applying ink droplets to a recording medium. The recording medium is transported with the Y direction as the transport direction. The recording unit 100 is an inkjet recording device equipped with a so-called serial type recording head, in which a carriage 101 equipped with a recording head 102 moves back and forth in the X direction intersecting the Y direction to perform recording. However, the recording method is not limited to this. For example, it may be an inkjet recording device equipped with a so-called line type recording head in which the nozzle row is configured to span the recording width in the Y direction. It may also be a multifunction peripheral device (MFP) that integrates not only recording functions but also scanning functions, fax functions, transmission functions, etc. It may also be an electrophotographic recording device that uses powder toner instead of liquid ink.

[0021] An input / output unit 109 is provided above the recording unit 100. The input / output unit 109 is an operation panel that displays the ink level and a list of recording media types on its display. The user can select the type of recording media and configure recording settings by operating the keys on the input / output unit 109.

[0022] The carriage 101 has a recording head 102 on the surface facing the transport path P of the recording medium, which includes a nozzle for ejecting ink supplied from the ink tank 111. The carriage 101 is configured to reciprocate along the shaft 104 via the carriage belt 103 in the X direction (direction of carriage movement) by the drive of a motor.

[0023] In this embodiment, paper 105 such as roll paper or cut paper is used as the recording medium, but the recording medium is not limited to paper. The paper 105 is transported in the Y direction on the platen 106 by transport rollers 205 and 206. When multiple jobs are printed on roll paper, printing is done continuously on the paper, so printing and drying are repeated continuously. On the other hand, when using cut paper, one job is printed on each sheet of cut paper, so printing and drying are performed only once each. It can be done.

[0024] On the paper 105, which has been transported onto the platen 106 by the transport rollers 205 and 206, the carriage 101 moves the recording head 102 in the X direction. The recording operation is performed by ejecting ink droplets as the recording head 102 moves. When the carriage 101 moves to the edge of the recording area on the paper 105, the transport rollers 205 and 206 transport a certain amount of the paper 105 in the transport direction (a direction intersecting the reciprocating direction), moving the area for the next recording scan to a position where the recording head 102 can record. By repeating the above operations, an image is recorded.

[0025] In this embodiment, a latex recording device that records images with latex ink is used as the recording unit 100. In contrast, in a typical inkjet recording device using water-based ink, an ink-receiving layer is required on the recording medium to catch the ink and prevent bleeding. On the other hand, in a latex recording device, when heat is applied to the latex ink, the water evaporates, the latex resin melts and mixes with the pigment, and a film is formed on the surface of the paper and hardens. Therefore, a latex recording device can record images even on a recording medium that does not have an ink-receiving layer.

[0026] In this embodiment, the recording medium after image recording is transported to the fuser 108. Heat is then applied to the recording medium in the fuser 108, causing the ink to harden and fix (finished state), and the paper is discharged from the fuser 108. After being discharged from the fuser 108, the paper is cut by the cutter 112 as needed.

[0027] Figure 3 is a schematic cross-sectional view showing the transport configuration of the recording medium. Paper 105 wound into a roll is attached to the paper feed section 209 of the printing device 050 as the recording medium. The paper 105 fed from the paper feed section 209 is held at the top and bottom by transport rollers 205 and 206 and transported in the transport direction F as the transport rollers 205 and 206 rotate.

[0028] An encoder sensor 215 is mounted so as to sandwich the upper transport roller 205 of the paper 105. A general-purpose encoder capable of measuring the amount of paper transported from the rotation speed of the roller can be used as the encoder sensor 215.

[0029] When measuring the transport volume using the encoder sensor 215, depending on the weight and surface characteristics of the attached paper 105, the transport roller 205 may slip, potentially preventing accurate measurement of the transport volume. To prevent this, the user may perform band adjustment from the input / output unit 109. There are two band adjustment methods: "automatic" and "manual". In "automatic" mode, a specific pattern is recorded in the main scanning direction (the direction intersecting the transport direction of the recording medium), and the density of that specific pattern is read multiple times by the multi-sensor. The transport volume is then corrected based on the density difference. In "manual" mode, a scale with inch or centimeter intervals is recorded, and the user manually inputs the correction amount percentage into the input / output unit 109 based on their visual judgment, thereby correcting the transport volume. This helps maintain the accuracy of the transport volume measurement.

[0030] Furthermore, a paper type identification sensor 212 is mounted near the transport roller 206. The paper type identification sensor 212 estimates the type of paper 105 by detecting at least one of the surface characteristics and basis weight of the paper 105.

[0031] In this embodiment, the side of the transport path P closest to the paper feeding unit 209 is called the upstream side, and the side closest to the winding unit 210 is called the downstream side. The paper 105 is supported from below by the platen 106, and an optical sensor 214 is mounted near the platen 106.

[0032] In this embodiment, an optical sensor 214 similar to those used in PC mice is used as the optical sensor 214. The optical sensor 214 has an illumination unit that emits light such as infrared light, and a paper 105 The optical sensor 214 has a light-receiving section that receives reflected light from the surface, and calculates the transport amount by detecting changes in surface characteristics caused by the transport of the paper 105. The optical sensor 214 can generally calculate the transport amount with higher accuracy than the encoder sensor 215.

[0033] The optical sensor 214 is not limited to the above configuration. For example, the optical sensor 214 could be a CMOS image sensor that detects the amount of displacement incurred during paper transport based on a surface image acquired by capturing an image of the paper surface.

[0034] In Embodiment 1 of this disclosure, an optical sensor 214 is used as the main device for measuring the amount of paper being transported. On the other hand, in Embodiment 2, an encoder sensor 215 is used as the main device for measuring the amount of paper being transported, and an optical sensor 214 is used as a sub-device for correcting the measured values.

[0035] As described above, the carriage 101 of the recording unit 100 is equipped with a recording head 102 that performs recording by ejecting ink from nozzles. Here, the nozzle furthest upstream of the nozzles of the recording head 102 is called the upstream nozzle 204, and the nozzle furthest downstream is called the downstream nozzle 202. It is also preferable to mount a multi-sensor 213 on the carriage 101. The multi-sensor 213 can estimate the type of paper from the thickness of the paper 105 and the illuminance of the reflected light from the paper 105.

[0036] The paper 105, on which the image has been recorded by the recording head 102, is further transported in the transport direction F and arrives at the fuser 108. The fuser 108 fixes the ink onto the paper using heat. After that, the paper 105 is transported further and wound onto the winding unit 210. If the paper needs to be cut, the cutter 112 performs the cutting process.

[0037] Figure 4 is a flowchart illustrating an example of basic operation in this embodiment, showing the basic flow from the start of paper feeding to the end of printing. This flow starts with a user's print start command. Each step of this flow is executed by the operation of each component of the printing device 050 under the control of the CPU 005. First, in step S400, a roll of paper 105 is unwound from the paper feed unit 209 and paper feeding begins. Next, in step S410, the paper 105 is transported by the transport rollers 205 and 206.

[0038] Next, in step S420, the paper type identification sensor 212 estimates the type of paper 105. Then, in step S430, the transport rollers 205 and 206 transport the leading edge of the paper 105 toward the position of the optical sensor 214. While the transport rollers 205 and 206 are driving, the CPU 005 can measure the amount of paper being transported based on the output signal of the encoder sensor 215.

[0039] Next, in step S435, the CPU 005 determines whether the leading edge of the paper 105 has reached the optical sensor 214 based on the output signal of the optical sensor 214. If it has reached the optical sensor 214 (S435=Yes), the process proceeds to step S440, where the CPU 005 switches the transport amount measurement method from the encoder sensor 215 to the optical sensor 214. The transport amount of the paper 105 until it reaches the optical sensor 214 is calculated based on the output of the encoder sensor 215, and the transport amount after it reaches the optical sensor 214 is calculated based on the output of the optical sensor 214, thereby enabling seamless calculation of the transport amount from the start of paper feeding.

[0040] On the other hand, if the paper 105 has not reached the position of the optical sensor 214 (S435=No), step S430 is repeated.

[0041] Next, in step S450, the transport rollers 205 and 206 transport the recording area of ​​the paper 105 to the recording position directly below the recording head of the recording unit 100. The recording area is in the transport direction. It could be the leading edge area of ​​paper 105, or an area set a distance from the leading edge of the paper.

[0042] Next, in step S455, the CPU 005 determines whether the leading edge of the recording area has been transported to the recording position based on the transport amount. If it has reached the position (S455=Yes), the process proceeds to step S460, and the recording head 102 begins image recording. On the other hand, if the leading edge of the recording area has not reached the recording position (S455=No), step S450 is repeated. During image recording, the transport amount of the paper 105 is instructed by the CPU 005 each time the recording head 102 mounted on the carriage 101 makes one round trip. Then, while continuing to measure with the encoder sensor 215 or optical sensor 214, the instructed transport amount is transported by the transport rollers 205 and 206.

[0043] Next, in step S465, the CPU 005 determines whether recording has been completed up to the end of the recording area. If it is completed (S465=Yes), the process proceeds to step S470. On the other hand, if recording is not completed (S465=No), recording continues. In step S470, the transport rollers 205 and 206 transport the paper 105 to the cut position. Next, in step S480, the cutter 112 cuts the paper 105. Once the above is complete, the recording is completed in step S490.

[0044] Furthermore, if the image recording output is wound up by the winding unit 210, or if the user performs the cutting manually, steps S470 to S480 do not need to be performed.

[0045] The basic method for measuring the transport volume according to the embodiment has been explained above using Figure 4. With this method, measurement is performed by the encoder sensor 215 until the paper 105 reaches the area where the optical sensor 214 can be used. Therefore, by performing highly accurate measurements with the optical sensor 214 as far as possible while also using the encoder sensor 215, seamless transport volume measurement becomes possible. However, as mentioned above, depending on the type of recording medium, the accuracy of the optical sensor 214 may decrease or measurement may become impossible. Therefore, in the following description, a transport volume measurement method adapted to various recording media will be explained with reference to several embodiments.

[0046] <Example 1> Figure 5 is a flowchart of the paper transport operation in Example 1. The main device used for measuring the amount of paper 105 transported is an optical sensor 214, which is generally considered to have high accuracy. The amount of paper transported is mainly measured when the paper 105 is fed into the recording unit 100 and when the recording operation is performed, but Example 1 shows the measurement of the amount of paper transported during paper feeding as an example. In Figure 4, the devices were switched in the order of encoder sensor 215 to optical sensor 214 as the transport progressed, but in this example, the measurement is performed in a partially different flow.

[0047] In step S500, the transport of the paper 105 begins as the transport rollers 205 and 206 rotate. This corresponds to step S410 in Figure 4. Next, in step S420, the paper type is estimated by the paper type identification sensor 212, as in Figure 4.

[0048] Next, in step S505, the CPU 005 determines, based on the estimated paper type, whether the paper 105 is of a type that is difficult to measure the transport amount of with the optical sensor 214. For example, if the type of recording medium is a recording medium that easily transmits light, such as film (a recording medium whose light transmittance is above a predetermined value), measurement by the optical sensor 214 is considered difficult. If measurement is difficult (S505=Yes), the process proceeds to step S510. On the other hand, if the type of recording medium is not difficult to measure, such as plain paper or glossy paper (S505=No), the process proceeds to step S520. Here, the predetermined value of transmittance, which serves as the standard for how easily the recording medium transmits light, can be determined based on the performance of the optical sensor 214 and the required level for recording control.

[0049] Here, a recording medium employing an optical sensor 214 during measurement is designated as the first type, and a recording medium employing an encoder sensor 215 is designated as the second type, which is different from the first type. In other words, in this embodiment, the measurement method may differ when two different types of recording media are used. A typical first type of recording medium is plain paper. Other possible first types of recording media include glossy paper, cardboard, and cloth. A typical second type of recording medium is film.

[0050] Furthermore, classifications other than the first and second types may be established. For example, glossy paper may be designated as the third type of recording medium, cardboard as the fourth type, and cloth as the fifth type, and measurement methods suitable for each type may be stored in ROM006 in advance.

[0051] In step S510, the CPU 005 measures the transport amount using the encoder sensor 215 instead of the optical sensor 214. In addition to the estimation results from the paper type identification sensor 212, the CPU 005 may also determine whether it is difficult to measure the transport amount using the optical sensor 214 based on the measurement results from the optical sensor 214 itself. For example, if the optical sensor 214 cannot read a certain number of feature quantities on the paper surface, it can be determined that measurement is difficult.

[0052] On the other hand, if the process proceeds to step S520, the CPU 005 is set to measure the transport amount using the optical sensor 214. As in the case of Figure 4, the measurement value from the encoder sensor 215 is used until the paper 105 reaches the optical sensor 214, and thereafter the paper reaches the optical sensor 214, thereby enabling seamless measurement. Furthermore, if the same type of paper is set again thereafter, the transport amount estimation method used at this time may be used again. After that, the process proceeds to step S530, and the transport of the paper 105 to the recording position is completed. From there, the process merges with Figure 4 to perform image recording and post-processing.

[0053] (modified version) Even if the determination in step S505 results in the adoption of measuring the transport volume using the encoder sensor 215 (leading to step S510), the measurement of the transport volume using the optical sensor 214 may be continued. If the difference between the measurement results of the optical sensor 214 and the encoder sensor 215 is greater than or equal to a predetermined range (for example, ±10 mm), the user may be prompted to perform band adjustment. Figure 7 shows the flowchart for this case, and Figure 8 shows an example of the display screen when prompting the user to perform band adjustment. The flow in Figure 7 will be described later.

[0054] The method for determining the paper type is not limited to the paper type identification sensor 212. For example, the user may input the type of recording medium installed using the input / output unit 109. If the user inputs that the paper type is film, the CPU 005 will use the measurement value from the encoder sensor 215.

[0055] Furthermore, the CPU005 may adopt the prediction result from the paper type identification sensor 212 only if there are no user input settings. Alternatively, the CPU005 may prioritize the use of user settings, but may also determine whether the prediction result from the paper type identification sensor 212 matches the user settings, and notify the user if they do not match.

[0056] Alternatively, paper type information may be stored on an identification medium attached to the recording medium and read by the printing device 050. The identification medium may be, for example, an IC tag or barcode attached to the core of a roll of paper.

[0057] According to this embodiment, the optical sensor 214 determines whether the recording medium is usable and if it is usable. When possible, highly accurate measurements are performed using the optical sensor 214; when it is unavailable, reliable measurements are performed using the encoder sensor 215. This increases the availability of conveyance volume measurement while achieving the highest possible accuracy.

[0058] <Example 2> Figure 6 is a flowchart showing the paper transport operation in Example 2. In Example 2, an encoder sensor 215 is used as the main device for measuring the transport amount. An optical sensor 214 is used for correcting the measured values. As in Example 1, Example 2 also shows the paper transport operation in the paper feeding operation as an example.

[0059] Steps S500 to S420 proceed in the same manner as in Example 1 (Figure 5). In this example, the measurement by the encoder sensor 215 in step S510 and the measurement by the optical sensor 214 in step S520 are performed in parallel.

[0060] The process then proceeds to step S600, where the CPU 005 adopts the measurement value from the encoder sensor 215 as the transport amount. However, in the next step S605, the CPU 005 determines whether there is a difference between the measurement value from the encoder sensor 215 and the measurement value from the optical sensor 214. The CPU 005 may also determine whether the difference in the measurement values ​​is within a predetermined range. If the difference is greater than the predetermined range (S605=Yes), the process proceeds to step S610. In step S610, the CPU 005 corrects the measurement value from the encoder sensor 215 with the measurement value from the optical sensor 214. The process then proceeds to step S530, and the transport of the paper to the recording position is completed. On the other hand, if there is no difference in the measurement values ​​(S605=No), the process is completed as is.

[0061] (modified version) Figure 7 is a flowchart of a modified example. Steps S500 to S520 proceed as in Figure 6. Next, in step S700, the CPU 005 compares the measurement results of the optical sensor 214 and the encoder sensor 215. Next, in step S705, the CPU 005 determines whether the comparison result is greater than or equal to a predetermined value (here, ±10 mm). If the comparison result is greater than or equal to the predetermined value (S705=Yes), the process proceeds to step S710, prompting the user to perform band adjustment. On the other hand, if the comparison result is less than the predetermined value (S705=No), the process proceeds to step S530 to complete the process.

[0062] Figure 8 shows an example of a screen displayed on the input / output unit 109 to prompt band adjustment. Window 800 displays a message prompting band adjustment, along with a "Yes" button 805 and a "No" button 810. If the user selects the "Yes" button 805 (S715=Yes), the CPU 005 performs the band adjustment.

[0063] On the other hand, if the user selects the "No" button (S715=No), the process proceeds to step S730, where the transport volume measurement result from the encoder sensor 215 is adopted without any adjustments. Subsequently, the process proceeds to step S530, and the transport is completed.

[0064] Furthermore, even if transport volume measurement by the encoder sensor 215 is employed in step S510, if a paper type that is difficult to correct the transport volume by band adjustment is set, band adjustment may be performed each time the winding diameter of the paper 105 decreases by a certain amount. Paper types that are difficult to correct the transport volume by band adjustment may be determined from the size, weight, and surface characteristics of the paper. Also, paper types that are difficult to measure the transport volume with the optical sensor 214 or correct the transport volume by band adjustment may be stored in NVRAM 008 in advance. In addition, as described above, both manual and automatic band adjustment can be employed. Furthermore, instead of a message prompting band adjustment, or together with a message prompting band adjustment, a message prompting the user to check the status of the paper 105 may be notified.

[0065] As described above, while the optical sensor 214 can measure the amount of paper 105 being transported with high accuracy, accuracy may decrease or measurement may become difficult if the paper type is film or similar. Therefore, in this invention, the system estimates whether the paper 105 is a type of paper for which measurement by the optical sensor 214 is difficult, based on the identification result of the paper type identification sensor 212 or user settings. If it is determined that measurement is difficult, the system switches to measuring the amount of paper being transported using the encoder sensor 215. This makes it possible to measure the amount of paper being transported regardless of the type of paper. As a result, the printing device can accurately measure the amount of paper being transported according to the type of recording medium.

[0066] [Configuration 1] A transport unit that transports recording media along a transport path, A first measuring unit is provided in the transport path and measures the amount of a recording medium being transported based on light from the recording medium, A second measuring unit is provided in the transport path and measures the amount of a recording medium transported based on the drive amount of the transport unit, A recording unit that records images onto a recording medium, A printing apparatus comprising: a control unit that controls recording by the recording unit based on the measurement result of the first measuring unit when the recording medium is of a first type, and controls recording by the recording unit based on the measurement result of the second measuring unit when the recording medium is of a second type different from the first type. [Configuration 2] The printing apparatus according to configuration 1, characterized in that the first measuring unit is an optical sensor having an irradiating unit that irradiates light onto a recording medium and a light receiving unit that receives reflected light from the recording medium. [Configuration 3] The printing apparatus according to configuration 1, characterized in that the first measuring unit measures the transport amount by acquiring a surface image of the recording medium. [Structure 4] The printing apparatus according to any one of configurations 1 to 3, characterized in that the second measuring unit is an encoder sensor provided on a transport roller of the transport unit. [Composition 5] The printing apparatus according to any one of configurations 1 to 4, characterized in that the control unit performs the control based on the measurement result of the second measurement unit when the light transmittance of the recording medium is greater than or equal to a predetermined value. [Composition 6] The printing apparatus according to any one of configurations 1 to 5, characterized in that the control unit performs the control based on the measurement result of the second measuring unit when the recording medium is a film. [Composition 7] The printing apparatus according to any one of configurations 1 to 6, further comprising an identification unit provided in the transport path for identifying the type of recording medium. [Structure 8] The printing apparatus according to configuration 7, characterized in that the identification unit performs identification by detecting at least one of the surface characteristics of the recording medium and the basis weight. [Composition 9] The printing apparatus according to configuration 7, characterized in that the identification unit performs identification by reading an identification medium attached to the recording medium. [Configuration 10] It further has an input section that accepts input from the user, The printing apparatus according to any one of configurations 1 to 9, characterized in that the control unit determines the type of recording medium based on the input from the input unit. [Composition 11] In the aforementioned transport path, the first measuring unit is located downstream of the second measuring unit. The printing apparatus according to any one of configurations 1 to 10, characterized in that the control unit performs control using the measurement value of the second measurement unit, at least until the recording medium reaches the first measurement unit. [Composition 12] The printing apparatus according to any one of configurations 1 to 11, characterized in that the control unit corrects the measurement result of the second measuring unit with the measurement result of the first measuring unit. [Composition 13] The printing apparatus according to configuration 12, characterized in that the control unit performs the correction when the difference between the measurement result of the second measurement unit and the measurement result of the first measurement unit is greater than or equal to a predetermined range. [Composition 14] It also includes an output unit that outputs information to the user, The printing apparatus according to configuration 12, characterized in that the control unit outputs a message to the output unit prompting the user to make a correction if the difference between the measurement result of the second measurement unit and the measurement result of the first measurement unit is greater than or equal to a predetermined range. [Composition 15] The printing apparatus according to any one of configurations 1 to 3, characterized in that the recording medium is wound in a roll shape. [Explanation of Symbols]

[0067] 005: CPU, 050: Printing device, 100: Recording unit, 105: Paper 205, 206: Transport rollers, 212: Paper type identification sensor, 214: Optical sensor, 215: Encoder sensor

Claims

1. A transport unit that transports recording media along a transport path, A first measuring unit is provided in the transport path and measures the amount of a recording medium being transported based on light from the recording medium, A second measuring unit is provided in the transport path and measures the amount of storage medium transported based on the drive amount of the transport unit, A recording unit that records images onto a recording medium, A printing apparatus comprising: a control unit that controls recording by the recording unit based on the measurement result of the first measuring unit when the recording medium is of a first type; and a control unit that controls recording by the recording unit based on the measurement result of the second measuring unit when the recording medium is of a second type different from the first type.

2. The printing apparatus according to claim 1, characterized in that the first measuring unit is an optical sensor having an irradiating unit that irradiates light onto a recording medium and a light receiving unit that receives reflected light from the recording medium.

3. The printing apparatus according to claim 1, characterized in that the first measuring unit measures the transport amount by acquiring a surface image of the recording medium.

4. The printing apparatus according to any one of claims 1 to 3, characterized in that the second measuring unit is an encoder sensor provided on a transport roller of the transport unit.

5. The printing apparatus according to any one of claims 1 to 3, characterized in that the control unit performs the control based on the measurement result of the second measurement unit when the light transmittance of the recording medium is greater than or equal to a predetermined value.

6. The printing apparatus according to any one of claims 1 to 3, characterized in that the control unit performs the control based on the measurement result of the second measuring unit when the recording medium is a film.

7. The printing apparatus according to any one of claims 1 to 3, further comprising an identification unit provided in the transport path for identifying the type of recording medium.

8. The printing apparatus according to claim 7, characterized in that the identification unit performs identification by detecting at least one of the surface characteristics of the recording medium and the basis weight.

9. The printing apparatus according to claim 7, characterized in that the identification unit performs identification by reading an identification medium attached to the recording medium.

10. It further has an input section that accepts input from the user, The printing apparatus according to any one of claims 1 to 3, characterized in that the control unit determines the type of recording medium based on the input from the input unit.

11. In the aforementioned transport path, the first measuring unit is located downstream of the second measuring unit. The printing apparatus according to any one of claims 1 to 3, characterized in that the control unit performs control using the measurement value of the second measurement unit, at least until the recording medium reaches the first measurement unit.

12. The printing apparatus according to any one of claims 1 to 3, characterized in that the control unit corrects the measurement result of the second measuring unit with the measurement result of the first measuring unit.

13. The printing apparatus according to claim 12, characterized in that the control unit performs the correction when the difference between the measurement result of the second measurement unit and the measurement result of the first measurement unit is greater than or equal to a predetermined range.

14. It also includes an output unit that outputs information to the user, The printing apparatus according to claim 12, characterized in that the control unit outputs a message to the output unit prompting the user to make a correction if the difference between the measurement result of the second measurement unit and the measurement result of the first measurement unit is greater than or equal to a predetermined range.

15. The printing apparatus according to any one of claims 1 to 3, characterized in that the recording medium is wound in a roll shape.

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