Recording device and control method

Abstract

This technology provides the ability to accurately detect the position of a recording medium, regardless of the type of recording medium used. [Solution] The device includes a recording head mounted on a recording medium, a carriage movable in the width direction of the recording medium intersecting the transport direction of the recording medium, a detection means for detecting the recording medium by having one or more of the multiple light-receiving elements provided on the carriage function as a light-receiving unit, an acquisition means for acquiring information about the type of the recording medium, and a setting means for setting the light-receiving elements to function as the light-receiving unit based on the information acquired by the acquisition means.

Description

Technical Field

[0001] The present disclosure relates to a recording apparatus and a control method.

Background Art

[0002] Patent Document 1 discloses a technique for detecting the position (end portion) of a recording medium by adjusting the amount of light of a light-emitting element according to the type of the recording medium and the variation in the output value of components. Further, Patent Document 2 discloses a technique for detecting the end portion of a recording medium by setting a detection threshold by multiplying a value greater than zero and less than one by the difference between the amount of reflected light of a reference reflecting plate (platen) and the amount of reflected light of the recording medium.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a reflection type photoelectric sensor is used as a sensor for detecting the position of a recording medium, the detection voltage changes because the reflectance of light differs depending on the type of the recording medium. For example, in the case of a recording medium with a low reflectance, a sufficient detection voltage may not be obtained and the position of the recording medium may not be detected because the detection threshold is not exceeded. In this case, if the amount of light of the light-emitting element is increased by the technique of Patent Document 1, a large current flows through the light-emitting element, and the life of the light-emitting element is shortened. Further, if the detection threshold is changed according to the detection voltage by the technique of Patent Document 2, in a recording medium with a low reflectance, the difference between the detection voltage and the detection threshold is small and the detection margin is reduced, and it becomes easy to be affected by noise or the like.

[0005] This disclosure has been made in view of the above-mentioned problems, and aims to provide a technology that can accurately detect the position of a recording medium regardless of the type of recording medium. [Means for solving the problem]

[0006] To achieve the above objective, one embodiment of the recording device according to the present disclosure is characterized by comprising: a carriage mounted on a recording head for recording on a recording medium and movable in the width direction of the recording medium intersecting the transport direction of the recording medium; a detection means for detecting the recording medium by having one or more of the photodetectors provided on the carriage function as a light-receiving unit; an acquisition means for acquiring information about the type of the recording medium; and a setting means for setting the photodetectors to function as the light-receiving unit based on the information acquired by the acquisition means. [Effects of the Invention]

[0007] According to this disclosure, the position of a recording medium can be detected with high accuracy, regardless of the type of recording medium. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic diagram of the recording mechanism. [Figure 2] A schematic diagram of the sensor configuration. [Figure 3] A diagram showing an example of the arrangement of light-receiving elements that form the light-receiving section of the first sensor. [Figure 4] A block diagram showing the functional configuration of the recording device. [Figure 5] A flowchart illustrating the processing routine for recording data. [Figure 6] A diagram illustrating the identification of the recording medium type by the second sensor. [Figure 7] This diagram shows the two light-receiving sections of the first sensor used to detect both ends of the recording medium in the width direction. [Figure 8] This diagram shows the two light-receiving sections of the first sensor used to detect the leading and trailing ends of the recording medium. [Figure 9]Figure showing a detection circuit connected to the first sensor. [Figure 10] Figure explaining the output waveform showing the change in the differential signal during tip detection. [Figure 11] Figure showing the positional relationship between the two light-receiving parts and the recording medium during tip detection. [Figure 12] Figure showing the output waveform of the differential signal according to the type of recording medium during tip detection. [Figure 13] Figure explaining the output waveform showing the change in the differential signal during rear-end detection. [Figure 14] Figure showing the positional relationship between the two light-receiving parts and the recording medium during rear-end detection. [Figure 15] Figure explaining the output waveform showing the change in the differential signal during detection of one end. [Figure 16] Figure showing the positional relationship between the two light-receiving parts and the recording medium during detection of one end. [Figure 17] Figure explaining the output waveform showing the change in the differential signal during detection of the other end. [Figure 18] Figure showing the positional relationship between the two light-receiving parts and the recording medium during detection of the other end. [Figure 19] Figure showing an example of a patch for position detection. [Figure 20] Figure explaining the output waveform showing the change in the differential signal during detection of the patch for position detection. [Figure 21] Figure explaining the change in the size of the spot area according to the thickness of the recording medium. [Figure 22] Figure showing the two light-receiving parts of the first sensor when detecting both ends in the width direction of cardboard. [Figure 23] Flowchart showing the processing routine of the recording process according to another embodiment.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, an example of an embodiment of a recording apparatus and a control method will be described in detail while referring to the attached drawings. Note that the following embodiments do not limit the present disclosure, and not all combinations of the features described in the present embodiment are essential for the solution means of the present disclosure. Also, the positions, shapes, etc. of the components described in the embodiment are merely examples, and are not intended to limit the scope of this disclosure only to them.

[0010] (First Embodiment) First, a recording apparatus according to the first embodiment will be described in detail while referring to FIGS. 1 to 20. In the present embodiment, as the recording apparatus, a multifunction printer having a reading function, a FAX function, etc. together with a recording function will be described as an example. Note that the apparatus to which the technology of the present disclosure is applicable may be any apparatus as long as it has a recording function capable of executing recording on a recording medium. In the description of the configuration of the recording apparatus, the configuration of the recording mechanism for recording on the recording medium will be mainly described.

[0011] <Configuration of Recording Apparatus> FIG. 1 is a schematic configuration diagram of a recording mechanism in a recording apparatus, (a) is a perspective view of the recording mechanism, and (b) is a schematic configuration diagram of a recording unit in the recording mechanism. FIG. 2 is a schematic configuration diagram of a sensor provided on a carriage. FIG. 3 is a diagram showing an example of the arrangement of light receiving elements forming a light receiving unit in a first sensor. In this specification, when facing the side where the recording medium after recording is discharged, the direction from the right side to the left side of the recording apparatus is defined as the X direction, the direction from the back side (rear side) to the front side (front side) of the recording apparatus is defined as the Y direction, and the direction from the lower side to the upper side of the recording apparatus is defined as the Z direction. Thus, the X direction, the Y direction, and the Z direction are directions from one side to the other side and are orthogonal to each other. In this specification, each direction is represented with a “+(plus)” when going from one side to the other side as appropriate, and is represented with a “-(minus)” when going from the other side to one side.

[0012] The recording device 10 includes a recording mechanism 11 comprising a transport unit 12 for transporting the recording medium M, and a recording unit 14 for ejecting ink onto the recording medium M transported by the transport unit 12 to record data (see Figure 1(a)).

[0013] The transport unit 12 includes a tray 16 on which the recording medium M is placed, a cassette (not shown) containing the recording medium M, and a transport roller 18 (see Figure 1(b)) that transports the recording medium M fed from the tray 16 and cassette in the Y direction. The transport roller 18 includes a drive roller 18a that rotates by the drive of a transport motor (not shown), and a driven roller 18b that is pressed against and driven by the drive roller 18a. The recording medium M fed from the tray 16 and cassette is nipped by the drive roller 18a and the driven roller 18b, and transported in the Y direction by the drive of the drive roller 18a.

[0014] The recording unit 14 includes a recording head 20 that ejects ink, and a carriage 22 on which the recording head 20 is mounted and which is movable in the X direction. The carriage 22 is slidably mounted on a guide rail 26 that extends in the X direction, and is configured to move from one side to the other in the X direction (+X direction) and from the other side to the one side (-X direction) via a belt 30 driven by a carriage motor 28. Therefore, in the recording unit 14, the recording head 20 mounted on the carriage 22 is also capable of reciprocating movement in the X direction via the carriage 22.

[0015] The recording unit 14 includes a platen 24 that supports the recording medium M transported by the transport unit 12, at a position opposite to the recording head 20 which moves via the carriage 22. In the recording unit 14, the recording head 20 ejects ink from the recording medium M, which is transported in the +Y direction (transport direction) and supported by the platen 24, while moving in the width direction (±X direction) of the recording medium M via the carriage 22. In this embodiment, the platen 24 has the characteristic of absorbing irradiated light and not reflecting, or reflecting, said light. The recording head 20 has a nozzle row formed on the surface opposite to the platen 24, in which multiple nozzles for ejecting ink are arranged side by side. This nozzle row extends in the Y direction, which intersects (orthogonal in this embodiment) with the direction of movement of the recording head 20 (X direction).

[0016] In the recording mechanism 11, a recording operation is performed on the recording medium M, which has been transported to the recording start position by the transport unit 12, by ejecting ink while moving (scanning) the recording head 20 in the X direction based on the recording data. Next, the transport unit 12 performs a transport operation to transport the recording medium M by a predetermined amount, and then performs the recording operation again. In this way, the recording mechanism 11 performs recording on the recording medium M based on the recording data by repeatedly and alternately executing the recording operation and the transport operation.

[0017] In the recording mechanism 11, the carriage 22 is provided with a first sensor 202 and a second sensor 204 capable of detecting the recording medium M (see Figure 2). The first sensor 202 is located upstream of the recording head 20 in the +Y direction (transport direction) in the carriage 22, and the second sensor 204 is located upstream of the first sensor 202 in the +Y direction in the carriage 22.

[0018] The first sensor 202 includes a light-emitting member 212 capable of irradiating light onto a recording medium M supported by a platen 24, and a light-receiving member 214 capable of receiving reflected light from the recording medium M irradiated by the light-emitting member 212. In this embodiment, the light-emitting member 212 is located upstream of the light-receiving member 214 in the +Y direction, but is not limited to this. The light emitted from the light-emitting member 212 is irradiated onto the platen 24 and the recording medium M supported by the platen 24 through an aperture 216 provided in the carriage 22. The reflected light from the recording medium M is received by the light-receiving member 214 through the aperture 218.

[0019] The light-receiving member 214 is equipped with multiple photo-receiving elements 300 so as to be able to receive reflected light incident through the opening 218 (see Figure 3). Specifically, the light-receiving member 214 has multiple photodiode arrays (PD arrays) 302, each consisting of multiple photo-receiving elements 300 arranged along the X direction, arranged in parallel along the Y direction. In this embodiment, four PD arrays 302, each formed by 16 photo-receiving elements 300, are arranged in parallel along the Y direction. More specifically, in the +Y direction, PD arrays 302a, 302b, 302c, and 302d are arranged in this order. PD arrays 302a and 302b are adjacent without any gaps, and PD arrays 302c and 302d are adjacent without any gaps. A gap G is provided between PD array 302b and PD array 302c.

[0020] The arrangement of the light-receiving elements 300 provided on the light-receiving member 214 is not limited to the arrangement shown in Figure 3. For example, a group of PD arrays 302 provided on one side of a gap G in the Y direction may be formed from three or more PD arrays 302. Similarly, a group of PD arrays 302 provided on the other side of a gap G in the Y direction may be formed from three or more PD arrays 302. Furthermore, the number of light-receiving elements 300 forming one PD array 302 may be more than 16 or less than 16. Moreover, the number of PD arrays 302 provided on the light-receiving member 214 may be five or more, two or three. Alternatively, multiple PD arrays 302 may be arranged side by side in the Y direction without any gap G. In this case, for example, multiple light-receiving elements 300 may be arranged in a matrix in the X and Y directions. Furthermore, although the PD array 302 is designed so that adjacent photodetectors 300 are arranged without any gaps between them, they may also be arranged with a certain distance between them.

[0021] The second sensor 204 includes a light-emitting member 222 capable of irradiating light onto a recording medium M supported by a platen 24, and a light-receiving member 224 capable of receiving reflected light from the recording medium M irradiated by the light-emitting member 222 (see Figure 2). In this embodiment, the light-emitting member 222 is located upstream of the light-receiving member 224 in the +Y direction, but is not limited to this. The second sensor 204 is a so-called reflective photosensor, a photoelectric conversion member incorporating a light-emitting member 222 and a light-receiving member 224, and the light-emitting surface of the light-emitting member 222 and the light-receiving surface of the light-receiving member 224 are arranged to face the recording medium M supported by the platen 24.

[0022] <Functional configuration of the recording device> Next, the functional configuration of the recording device 10 will be described. Figure 4 is a block diagram showing the functional configuration of the recording device 10.

[0023] The recording device 10 includes a control unit 400 that controls the entire recording device 10, and an operation unit 402 that displays various information about the recording device 10 and accepts input from the user.

[0024] The control unit 400 includes a central processing unit (CPU) 404, a ROM 406, and a RAM 408. The CPU 404 loads various control programs stored in the ROM 406 into the RAM 408 to control the various configurations of the recording device 10, which will be described later. The RAM 408 is a read / write memory composed of DRAM, and in addition to the area for loading control programs, it has an area for temporarily storing various types of data. For example, the RAM 408 stores image data read by the reading unit 418 (described later) and obtained via the image processing unit 420 (described later), as well as recording data used for recording in the recording unit 14. The RAM 408 can also store binarized facsimile data transmitted and received to and from subscriber lines by the facsimile (FAX) unit 426 (described later).

[0025] The control unit 402 includes operation buttons (not shown) such as a power key, operation start key, operation stop key, and home position key, as well as a display unit (not shown) equipped with a touch sensor. The control unit 402 is a user interface for performing various operations and settings of the recording device 10.

[0026] The recording device 10 includes a power supply unit 410 controlled by a CPU 404. The power supply unit 410 includes, for example, a switching power supply that outputs DC +24V / +32V voltage from commercial AC voltage. The power supply unit 410 also includes a DC / DC converter that outputs DC +1.0V / 1.5V / +3.3V / +5.0V for use in the logic unit from the DC +32V from the switching power supply.

[0027] The recording device 10 includes a USB interface (I / F) unit 412 controlled by the CPU 404. The USB I / F 412 is connected to a host computer (HostPC) (not shown) via a USB cable. It transfers recording data from the HostPC, scan data read by the reading unit 418, and read / write data to the memory connected to the memory I / F unit 428 (described later).

[0028] The recording device 10 includes a wired LAN interface 414 controlled by the CPU 404. The wired LAN interface 414 is, for example, equipped with an RJ-45 connector and is a 10Base-T / 100Base-TX compliant LAN interface that transmits and receives data with a Host PC connected to the network via a switching hub.

[0029] The recording device 10 includes a wireless LAN interface unit 416 controlled by the CPU 404. The wireless LAN interface unit 416 is, for example, a wireless LAN interface compliant with IEEE 802.11n / 11g / 11b, and transmits and receives data with a Host PC connected to the network via a wireless LAN router. It is also possible to transmit and receive data by directly connecting to mobile devices such as smartphones and tablets without a wireless LAN router.

[0030] The recording device 10 includes a reading unit 418 controlled by a CPU 404. The reading unit 418 includes a photoelectric conversion unit such as a contact image sensor (CIS) or a CCD, and sequentially transmits the image data of the original document read via the CIS or CCD based on the control of the CPU 404 to the image processing unit 420.

[0031] The recording device 10 includes an image processing unit 420 controlled by the CPU 404. The image processing unit 420 includes a clock supply circuit for controlling the reading unit 418, a peak hold circuit, a shading correction circuit, an A / D conversion circuit, and a DMA controller. The image processing unit 420 converts the image data read by the reading unit 418 into digital data, performs image processing, and transfers the processed data to the RAM 408.

[0032] The recording device 10 includes a recording unit 14 controlled by a CPU 404. The recording unit 14 includes a DMA controller, a head control logic circuit, a recording head 20, and an ink cartridge. Under the control of the CPU 404, the recording unit 14 can retrieve the recorded data stored in the RAM 408 and print it out as a hard copy.

[0033] The recording device 10 includes a drive unit 422 controlled by a CPU 404. The drive unit 422 includes various motors for driving the drive mechanisms of various components in the recording device 10. Specifically, the drive unit 422 includes a scanner motor for automatically reading documents placed on the document glass of the reading unit 418, an automatic document feeder (ADF) motor for automatically transporting multiple documents, and a transport motor for driving the drive roller 18a (see Figure 1(b)). The drive unit 422 also includes a feed motor for driving the feed mechanism for feeding the recording medium M from the tray 16 and cassette, and an ejection motor for driving the ejection mechanism for ejecting the recording medium M after recording. In addition, the drive unit 422 includes a carriage motor 28 (see Figure 1(a)) for moving the carriage 22, and so on. Furthermore, the drive unit 422 includes a recovery motor for driving a cleaning mechanism for cleaning the recording head 20 and the ink supply unit (not shown) that supplies ink to the recording head 20. The drive unit 422 includes a belt and gears that transmit driving force to the motors provided in the recording device 10, which includes the various motors described above, as well as a driver circuit that drives the motors.

[0034] The recording device 10 includes a sensor unit 424 controlled by a CPU 404. The sensor unit 424 includes various detection units for detecting the positions of various components in the recording device 10, the position of the transported recording medium M, the amount of motor drive, etc. Specifically, the sensor unit 424 includes a sensor for detecting the presence or absence of a document on the document glass of the reading unit 418, and sensors for detecting the presence or absence of the recording medium M in the tray 16 and cassette. The sensor unit 424 also includes sensors (first sensor 202, second sensor 204) for detecting the position of the recording medium M transported by the transport unit 12, and encoder sensors for detecting the amount of motor drive, etc. The CPU 404 monitors the detection results from the various sensors (detection units) and performs control according to the various detection results.

[0035] The recording device 10 includes a fax unit 426 controlled by a CPU 404. The fax unit 426 includes, for example, a V.34 / V.32 / V.32bis / V.17 / V.29 / V.27ter / V.23 / V.21(H / L) modem and a line control unit (NCU) that connects the subscriber circuit (PSTN) and the modem. The NCU is a subscriber line interface circuit conforming to the telephone line standards of each country, and performs line locking / delocking, call initiation / reception, impedance matching, and ensures isolation between the subscriber line and the modem for signal transmission. The modem receives analog signals from the subscriber line via the NCU, demodulates them, and stores the binarized data in the RAM 408. Alternatively, it modulates the transmission data stored in the RAM 408 and transmits it to the subscriber line via the NCU.

[0036] The recording device 10 is capable of receiving USB memory sticks, memory cards, etc., and includes a memory I / F unit 428 controlled by the CPU 404. The memory I / F unit 428 includes, for example, a USB Type A connector, various card slots, and a card controller IC. The memory I / F unit 428 reads data stored on connected USB memory sticks and various memory cards for recording in the recording unit 14, stores data scanned by the reading unit 418, and reads / writes data from the Host PC.

[0037] <Recording process> In the above configuration, the recording device 10 performs a recording process to record data onto the recording medium M based on the input job. Figure 5 is a flowchart detailing the recording process performed by the recording device 10 according to this embodiment. The series of processes shown in the flowchart of Figure 5 are performed by the CPU 404 expanding the program code stored in the ROM 406 into the RAM 408 and executing it. Alternatively, some or all of the functions of the steps in Figure 5 may be performed by hardware such as an ASIC or electrical circuit. In this specification, the symbol S in the description of each process in the flowchart means a step in that flowchart.

[0038] When the recording process begins, in S502, the CPU 404 first starts feeding the recording medium M placed on the tray 16 or the recording medium M contained in the cassette and transporting the fed recording medium M to the recording unit 14. Also in S504, the CPU 404 lights up the light-emitting member 222 of the second sensor 204. At this time, the carriage 22 is moved in the X direction to a position where the recording medium M can be detected by the second sensor 204. Then, in S506, the CPU 404 determines whether or not the recording medium M has been detected by the second sensor 204. In S506, the determination is made based on the detection result of the second sensor 204. For example, if the amount of light received by the light-receiving member 224 remains constant for a predetermined period of time or longer, it is determined that the recording medium M has been detected. Note that the method for detecting the recording medium M by the second sensor 204 is not limited to this, and various known technologies can be used. If it is determined in S506 that the recording medium M has been detected, the process proceeds to S508, where the CPU 404 determines, based on the detection result of the second sensor 204, whether or not the type of recording medium M is glossy paper.

[0039] Here, the determination of the type of recording medium M based on the detection results of the second sensor 204 will be explained with reference to Figure 6. Figure 6(a) shows a determination circuit 600 connected to the second sensor 204 for determining the type of recording medium M. Figure 6(b) shows a table in which data b1 / b0, the type of recording medium, and the selection pattern (described later) are associated.

[0040] In the second sensor 204, when reflected light from the recording medium M is received by the light-receiving member 224, a photocurrent IL flows. This photocurrent IL is converted into a voltage value VL in the current-voltage (IV) conversion circuit 602. The converted voltage value VL is input to the A / D conversion circuit 604, where it is compared with a preset threshold and converted into 2-bit data b1 / b0. The CPU 404 determines the type of recording medium M based on the converted data b1 / b0.

[0041] In this embodiment, the recording medium M can be of four types: glossy paper, plain paper, gray paper, and other. The light reflectance of these materials is highest for glossy paper, followed by plain paper, gray paper, and then other. Hereinafter, "light reflectance" will be simply referred to as "reflectance" as appropriate. The threshold used in the A / D conversion circuit 604 is set to decrease as the reflectance decreases. A storage area such as the ROM 406 stores a table that associates, for example, data b1 / b0, the type of recording medium, and the selected pattern (see Figure 6(b)). The CPU 404 refers to this table and determines the type of recording medium based on the data b1 / b0.

[0042] In this embodiment, when data b1 / b0 is "1 / 1", it is determined that the recording medium M is glossy paper; when it is "1 / 0", it is determined that the recording medium M is plain paper; when it is "0 / 1", it is determined that the recording medium M is gray paper; and when it is "0 / 0", it is determined that the recording medium M is something else. Therefore, in S508, the CPU 404 determines whether the data b1 / b0 output from the discrimination circuit 600 is "1 / 1" or not. Thus, in this embodiment, the CPU 404 functions as an acquisition unit that acquires data b1 / b0, to which the type of recording medium is associated, as information about the type of recording medium.

[0043] Returning to Figure 5, if it is determined in S508 that the type of recording medium M is glossy paper, the process proceeds to S510. In S510, the CPU 404 selects selection pattern 1 as the combination of photodetectors 300 that form the two light-receiving sections of the first sensor 202 used to detect the edges of the recording medium in the width direction, as described later, and proceeds to S522, which will be described later. In S510, selection pattern 1, which corresponds to "1 / 1" in the data b1 / b0 in the table in Figure 6(b), is selected. The combinations of photodetectors 300 selected by selection pattern 1 and selection patterns 2 to 4, which will be described later, will be described later.

[0044] In S508, if it is determined that the type of recording medium M is not glossy paper, the process proceeds to S512, where the CPU 404 determines whether or not the type of recording medium M is plain paper. In S512, the CPU 404 determines whether or not the data b1 / b0 output from the discrimination circuit 600 is "1 / 0". In S512, if it is determined that the type of recording medium M is plain paper, the process proceeds to S514, where the CPU 404 selects selection pattern 2 as the selection pattern described above, and proceeds to S522, which will be described later. In S514, in the table in Figure 6(b), selection pattern 2, which corresponds to "1 / 0" for data b1 / b0, is selected.

[0045] In S512, if it is determined that the type of recording medium M is not plain paper, the process proceeds to S516, where the CPU 404 determines whether or not the type of recording medium M is gray paper. In S516, the CPU 404 determines whether or not the data b1 / b0 output from the discrimination circuit 600 is "0 / 1". In S516, if it is determined that the type of recording medium M is gray paper, the process proceeds to S518, where the CPU 404 selects selection pattern 3 as the selection pattern described above, and proceeds to S522, which will be described later. In S518, in the table in Figure 6(b), selection pattern 3, which corresponds to "0 / 1" for data b1 / b0, is selected.

[0046] In S516, if it is determined that the type of recording medium M is not gray paper, the process proceeds to S520, where the CPU 404 determines that the type of recording medium M is "other," selects selection pattern 4 as the selection pattern described above, and proceeds to S522, which will be described later. In S520, in the table in Figure 6(b), selection pattern 4, which corresponds to "0 / 0" in data b1 / b0, is selected. Thus, in this embodiment, the CPU 404 functions as a setting unit that sets the light-receiving element to function as a light-receiving unit from among a plurality of light-receiving elements.

[0047] Here, we will describe the selection patterns for the combination of photodetectors 300 that form the two light-receiving sections of the first sensor 202 used to detect the widthwise edge of the recording medium M, that is, to detect the position of the recording medium M in the widthwise direction. Figure 7 shows the combination of photodetectors 300 that form the two light-receiving sections in each selection pattern, where (a) shows selection pattern 1, (b) shows selection pattern 2, (c) shows selection pattern 3, and (d) shows selection pattern 4. As will be described in detail later, the first sensor 202 is configured to detect the position of the edge of the recording medium M based on the output from two different light-receiving sections in the light-receiving member 214. Therefore, in each selection pattern, a group of photodetectors 300 to function as the first light-receiving section 702 and a group of photodetectors 300 to function as the second light-receiving section 704 are selected from among the photodetectors 300 in the light-receiving member 214.

[0048] In selection pattern 1, which is selected when the type of recording medium M is glossy paper with the highest reflectivity, two photodetectors located adjacent to each other at the center in the X direction of the PD array 302c are selected as the first photodetector 702 and the second photodetector 704, one element each. Specifically, in selection pattern 1, one photodetector located on the other side of the center in the X direction is selected as the first photodetector 702a, and one photodetector located on the one side of the center is selected as the second photodetector 704a (see Figure 7(a)).

[0049] In selection pattern 2, which is selected when the recording medium M is plain paper, which has the second highest reflectivity after glossy paper, four light-receiving elements located adjacent to each other at the center of the PD array 302c in the X direction are selected as two elements each for the first light-receiving section 702 and the second light-receiving section 704. Specifically, in selection pattern 2, two adjacent light-receiving elements located on the other side of the center in the X direction are selected as the first light-receiving section 702b, and two adjacent light-receiving elements located on one side of the center are selected as the second light-receiving section 704b (see Figure 7(b)).

[0050] In selection pattern 3, which is selected when the type of recording medium M is gray paper, which has the second highest reflectivity after plain paper, six photodetectors located adjacent to each other at the center of the PD array 302c in the X direction are selected as the first photodetector 702 and three as the second photodetector 704. Specifically, in selection pattern 3, three adjacent photodetectors located on the other side of the center in the X direction are selected as the first photodetector 702c, and three adjacent photodetectors located on one side of the center are selected as the second photodetector 704c (see Figure 7(c)).

[0051] In selection pattern 4, which is selected when the type of recording medium M is "other" with the lowest reflectivity, eight photodetectors located adjacent to each other at the center of the PD array 302c in the X direction are selected as the first photodetector 702 and the second photodetector 704, with four elements selected for each. Specifically, in selection pattern 4, four adjacent photodetectors located on the other side of the center in the X direction are selected as the first photodetector 702d, and four adjacent photodetectors located on one side of the center are selected as the second photodetector 704d (see Figure 7(d)).

[0052] Thus, in selection patterns 1 to 4, the number of photodetectors 300 forming one light-receiving section differs depending on the type of recording medium M. More specifically, in selection patterns 1 to 4, the number of photodetectors 300 forming one light-receiving section increases as the reflectivity of the type of recording medium M decreases. The above-described selection patterns 1 to 4 are stored in a memory area such as ROM 406.

[0053] The number of photodetectors 300 forming one light-receiving section in each of the above selection patterns is merely an example. In each selection pattern, the number of photodetectors 300 can be any number, as long as the recording medium has a lower reflectivity and the number of photodetectors 300 increases accordingly. When increasing the number of photodetectors 300, it is preferable to increase the number of photodetectors 300 along the direction of movement of the first sensor 202 relative to the recording medium M, i.e., the X direction, but it is also possible to increase the number of photodetectors 300 in the Y direction. Furthermore, in each of the above selection patterns, the photodetectors of the PD array 302c are selected as the photodetectors forming one light-receiving section, but this is not the only option. The photodetectors of the PD array 302a, PD array 302b, or PD array 302d may be selected as the photodetectors forming one light-receiving section. Alternatively, the photodetectors of multiple PD arrays 302 may be selected. Furthermore, in each of the above-described selection patterns, the first light-receiving unit 702 and the second light-receiving unit 704 are adjacent to each other without any gap between them, but the selection is not limited to this. In each selection pattern, the first light-receiving unit 702 and the second light-receiving unit 704 may be formed with a gap of one or more light-receiving elements between them.

[0054] Returning to Figure 5, once the selection pattern is determined, in S522, the CPU 404 detects the leading edge of the recording medium M. In S522, the leading edge of the recording medium M is detected by the first sensor 202. Specifically, in S522, the carriage 22 is moved to a position where the leading edge of the transported recording medium M can be detected by the first sensor 202, and the light-emitting member 212 of the first sensor 202 is illuminated. Thereafter, the position of the leading edge of the recording medium M is detected while transporting the recording medium M in the +Y direction. Note that in S522, the position of the Y-direction end of the recording medium M is detected not by the selection pattern determined immediately before, but by two light-receiving units that are pre-set to detect the leading and trailing ends of the recording medium M. Details of the detection of the leading edge of the recording medium M by the first sensor 202 performed in S522 will be described later.

[0055] When the leading edge of the recording medium M is detected, the process proceeds to S524, where the CPU 404 detects the edges of the recording medium M in the width direction (X direction). In S524, the first sensor 202 detects the edges ER on one side (right side) and EL on the other side (left side) of the recording medium M in the X direction. Specifically, in S524, the first sensor 202, moving in the X direction via the carriage 22, transports the recording medium M to a position where both ends of the recording medium M in the X direction can be detected. If the light-emitting member 212 was turned off at the end of S522, it is turned on here. Subsequently, while moving the carriage 22 in the X direction, the positions of the edges ER and EL of the recording medium M in the X direction are detected by the first sensor 202. In S524, the two light-receiving units (first light-receiving unit 702 and second light-receiving unit 704) in the light-receiving member 214 are set based on the selection pattern set in S510, S514, S518, or S520. Details of the detection of the edges ER and EL of the recording medium M by the first sensor 202, which is performed in S524, will be described later.

[0056] After detecting the ends ER and EL of the recording medium M, the process proceeds to S526, where the CPU 404 detects the rear end of the recording medium M. In S526, the first sensor 202 detects the rear end of the recording medium M. Specifically, in S526, the carriage 22 is moved to a position where the rear end of the conveyed recording medium can be detected by the first sensor 202. If the light-emitting member 212 was turned off at the end of S524, it is turned on here. Subsequently, the position of the rear end of the recording medium M is detected while conveying the recording medium M in the +Y direction. Details of the detection of the rear end of the recording medium M by the first sensor 202 performed in S526 will be described later.

[0057] Then, in S528, the CPU 404 controls the drive unit 422 and the recording unit 14, etc., based on the position information of the leading edge, trailing edge, end ER, and end EL of the recording medium M stored in the memory area, and performs recording on the recording medium M based on various setting information. In S528, after detecting the trailing edge of the recording medium M, it is transported in the -Y direction to the recording start position, and then recording to the recording medium M is started. By using the position information of the ends of the recording medium M detected in this way, for example, micro-margin recording can be performed with high accuracy, recording right up to the edges of all four sides of the recording medium M to obtain a visual effect equivalent to borderless recording. After that, in S530, the CPU 404 determines whether or not to perform recording on the next recording medium M. If it is determined in S530 to perform recording on the next recording medium M, the process returns to S502. If it is determined in S530 not to perform recording on the next recording medium, this recording process is terminated.

[0058] <Detection of the Y-direction edge of the recording medium> Next, we will describe the detection of the leading and trailing ends of the recording medium M by the first sensor 202.

[0059] =First light-receiving section and second light-receiving section= First, the first and second light-receiving sections of the light-receiving member 214, used for detecting the leading and trailing ends of the recording medium M, will be described. Figure 8 shows an example of the light-receiving elements 300 in the light-receiving member 214, which are selected as the first light-receiving section 802 and the second light-receiving section 804 when detecting the leading and trailing ends of the recording medium M.

[0060] For the first and second light-receiving units 802 and 804, which detect the leading and trailing ends of the recording medium M, the same light-receiving elements 300 are selected regardless of the type of recording medium M. Specifically, the first light-receiving unit 802 is selected to have four light-receiving elements: two adjacent light-receiving elements 300 at the center position in the X direction of the PD array 302a, and two adjacent light-receiving elements 300 at the center position in the X direction of the PD array 302b. The second light-receiving unit 804 is selected to have four light-receiving elements: two adjacent light-receiving elements 300 at the center position in the X direction of the PD array 302c, and two adjacent light-receiving elements 300 at the center position in the X direction of the PD array 302d. Furthermore, the photodetectors 300 selected as the first light-receiving unit 802 and the second light-receiving unit 804 are not limited to those described above, and may be offset to one side or the other side from the center position in the X direction in each PD array 302. Also, while it is preferable that the first light-receiving unit 802 and the second light-receiving unit 804 are located at positions that overlap in the X direction, they may be located such that one light-receiving unit is positioned to one side of the center position and the other light-receiving unit is positioned to the other side of the center position in the X direction. Moreover, the first light-receiving unit 802 and the second light-receiving unit 804 are located at positions that do not overlap with each other in the Y direction. In addition, the number of photodetectors constituting the first light-receiving unit 802 and the second light-receiving unit 804 is constant regardless of the type of recording medium M, but is not limited to this, and may be changed according to the type of recording medium M. In this case, the lower the reflectivity of the recording medium M, the greater the number of photodetectors constituting the light-receiving unit. The first light-receiving unit 802 and the second light-receiving unit 804 are of equal number.

[0061] =Detection Circuit= Next, a detection circuit for detecting the edge of the recording medium M will be described. Figure 9 shows a detection circuit connected to the first sensor 202 for detecting the edge of the recording medium M.

[0062] In the detection circuit 900, the selector 902 sets the photodetector 300 to be used for detection under the control of the CPU 404. When detecting the leading and trailing ends of the recording medium M, the CPU 404, via the selector 902, sets the four photodetectors of PD arrays 302a and 302b, as described in Figure 8, to function as the first photodetector 802. It also sets the four photodetectors of PD arrays 302c and 302d, as described in Figure 8, to function as the second photodetector 804.

[0063] When the CPU 404 lights up the light-emitting member 212 and reflected light from the recording medium M is input to each of the set photodetectors, a photocurrent Id flows in one photodetector and a photocurrent Id' flows in the other photodetector. In this embodiment, the photocurrent Id flowing through the photodetector 300, which functions as the first photodetector 802, is converted to a positive voltage value VA by the IV conversion circuit 904. The photocurrent Id' flowing through the photodetector 300, which functions as the second photodetector 804, is converted to a negative voltage value V / A by the IV conversion circuit 906. Note that the photocurrents Id and Id' are the sum of the currents flowing through each photodetector. Therefore, the photocurrents Id and Id' change depending on the number of photodetectors used.

[0064] The voltage value VA converted by the IV conversion circuit 904 and the voltage value V / A converted by the IV conversion circuit 906 are input to the differential amplifier 908. In this embodiment, the differential amplifier 908 outputs a differential signal Vout, which is the sum of the voltage values ​​VA and V / A amplified. The differential signal Vout output from the differential amplifier 908 is input to the A / D converter built into the CPU 404.

[0065] =Detection of the tip of recording medium M= Next, the detection of the leading edge of the recording medium M, performed in S522, will be described. In S522, while the recording medium M is transported in the +Y direction, the change in the differential signal Vout based on the output voltages of the first light receiving unit 802 and the second light receiving unit 804 is acquired, and the leading edge position of the recording medium M is detected based on this change.

[0066] • Changes in output voltage VA, output voltage V / A, and differential signal Vout This section describes the changes in output voltage VA, output voltage V / A, and differential signal Vout in the detection circuit 900 when detecting the leading edge of the recording medium M. Figure 10 illustrates the changes in output voltage by the two light-receiving units and the changes in the differential signal by the differential amplifier when detecting the leading edge of the recording medium M. Figure 10(a) is an output waveform showing the change in output voltage VA according to the amount of light received by the first light-receiving unit 802. Figure 10(b) is an output waveform showing the change in output voltage V / A according to the amount of light received by the second light-receiving unit 804. Figure 10(c) is an output waveform showing the change in the differential signal Vout. Figure 11 is a diagram showing the position of the light-receiving member 214 relative to the recording medium M being transported. Note that in Figure 11, some of the components of the recording unit 14 are omitted for ease of understanding. Also, in Figure 11, the leading edge of the recording medium M is indicated as "EF".

[0067] First, let's explain the change in output voltage VA. In the first sensor 202, the recording medium M being transported in the transport direction first enters the light-receiving area of ​​the first light-receiving unit 802, which is located upstream in the transport direction (+Y direction). The light-receiving area refers to the area in the light-receiving unit that can receive reflected light from the recording medium M. When the recording medium M enters the light-receiving area of ​​the first light-receiving unit 802, a photocurrent Id begins to flow in the detection circuit 900. As the transport of the recording medium M increases the proportion of the recording medium M that occupies the light-receiving area, the amount of light received by the first light-receiving unit 802 increases, and in accordance with this increase, the photocurrent Id increases, causing the output voltage VA from the IV conversion circuit 904 to rise (see Figure 10(a)). Subsequently, when only the recording medium M is located in the light-receiving area of ​​the first light-receiving unit 802, the output voltage VA maintains its positive electrode peak value. Therefore, the change in output voltage VA when detecting the tip of the recording medium M is as shown in output waveform 1002.

[0068] Next, the change in output voltage V / A will be explained. When the recording medium M is positioned across the entire light-receiving area of ​​the first light-receiving unit 802, and the recording medium M is further transported in the transport direction, the transported recording medium M enters the light-receiving area of ​​the second light-receiving unit 804. When the recording medium M enters the light-receiving area of ​​the second light-receiving unit 804, a photocurrent Id' begins to flow in the detection circuit 900. As the recording medium M is transported further, the proportion of the recording medium M that occupies the light-receiving area increases, and the amount of light received by the second light-receiving unit 804 increases. In response to this increase, the photocurrent Id' increases, and the output voltage V / A from the IV conversion circuit 906 decreases (see Figure 10(b)). Subsequently, when only the recording medium M is positioned within the light-receiving area of ​​the second light-receiving unit 804, the output voltage V / A maintains its negative peak value. Therefore, the change in output voltage V / A when detecting the tip of the recording medium M is as shown in output waveform 1004.

[0069] Next, the change in the differential signal Vout will be explained. The output voltage VA and output voltage V / A are input to the differential amplifier 908, and the differential amplifier 908 outputs a differential signal Vout, which is the amplified sum of the output voltage VA and output voltage V / A. Here, the output voltage VA increases from 0V in accordance with the increase in the amount of light received by the first light receiving unit 802 (see Figure 10(a)). On the other hand, the output voltage V / A decreases from 0V in accordance with the increase in the amount of light received by the second light receiving unit 804 (see Figure 10(b)).

[0070] Therefore, when the recording medium M is not located in the light-receiving area of ​​the first light-receiving unit 802 or the light-receiving area of ​​the second light-receiving unit 804 (see Figure 11(a)), the first light-receiving unit 802 and the second light-receiving unit 804 do not receive reflected light, or receive very little light. Consequently, in this case, both the output voltage VA and the output voltage V / A become 0V, and the differential signal Vout also becomes 0V (see region S1 in Figure 10(c)).

[0071] As the transport of the recording medium M progresses and the recording medium M begins to enter the light-receiving area of ​​the first light-receiving unit 802, and the proportion of the recording medium M in that light-receiving area increases (see Figure 11(b)), in the second light-receiving unit 804, only the platen 24 is located in its light-receiving area. Therefore, at this time, the output voltage VA rises from 0V, the output voltage V / A remains at 0V, and the differential signal Vout rises in accordance with the rise in output voltage VA (see area S2 in Figure 10(c)).

[0072] As the transport of the recording medium M progresses further, when the leading edge EF of the recording medium M is positioned between the light-receiving area of ​​the first light-receiving unit 802 and the light-receiving area of ​​the second light-receiving unit 804 in the Y direction (see Figure 11(c)), the recording medium M is positioned within the entire light-receiving area of ​​the first light-receiving unit 802. Also, the platen 24 is positioned within the entire light-receiving area of ​​the second light-receiving unit 804. Therefore, at this time, the output voltage VA maintains the peak value of the positive electrode, the output voltage V / A maintains 0V, and the differential signal Vout maintains the peak value of the positive electrode (see area S3 in Figure 10(c)).

[0073] As the transport of the recording medium M progresses further, and the recording medium M begins to enter the light-receiving area of ​​the second light-receiving unit 804, and the proportion of the recording medium M in that light-receiving area increases (see Figure 11(d)), the first light-receiving unit 802 has only the recording medium M located in its light-receiving area. Therefore, at this time, the output voltage VA maintains the peak value of the positive electrode, the output voltage V / A decreases from 0V, and the differential signal Vout decreases in accordance with the decrease in output voltage V / A (see area S4 in Figure 10(c)).

[0074] As the transport of the recording medium M progresses further, and the recording medium M is positioned within the entire light-receiving area of ​​the second light-receiving unit 804 (see Figure 11(e)), the recording medium M is also positioned within the entire light-receiving area of ​​the first light-receiving unit 802. Therefore, at this time, the output voltage VA maintains the peak value of the positive terminal, the output voltage V / A maintains the peak value of the negative terminal, and the differential signal Vout becomes 0V. Consequently, the change in the differential signal Vout when detecting the leading edge of the recording medium M is as shown in output waveform 1006.

[0075] Method for detecting the leading edge position of recording medium M Next, a method for detecting the leading edge position of a recording medium M based on the differential signal Vout will be described. Figure 12 shows the output waveform 1006 of the differential signal Vout when detecting the leading edges of different types of recording media.

[0076] When detecting the leading edge of a recording medium M, the peak value of the differential signal Vout depends on the output voltage VA, and therefore changes depending on the reflectivity of the recording medium M (type of recording medium M). For example, when detecting the leading edge of glossy paper with high reflectivity, the output waveform 1202 shows the change in the differential signal Vout. In this output waveform 1202, the peak value is higher than that of output waveform 1204, which shows the change in the differential signal Vout when detecting the leading edge of plain paper, and output waveform 1206, which shows the change in the differential signal Vout when detecting the leading edge of gray paper.

[0077] However, in these output waveforms, even if the peak value changes depending on the type of recording medium M, the width of the peak waveform remains almost unchanged, and the center position Pc in the width direction of the peak waveform also remains almost unchanged. Therefore, regardless of the type of recording medium M, the center position Pc of the peak waveform in the output waveform showing the change in the differential signal Vout corresponds to the tip of the recording medium M.

[0078] Therefore, in S522, the CPU 404 converts the differential signal Vout input to the A / D converter into digital data and generates an output waveform that shows the change in the differential signal Vout. The CPU then detects the center position Pc of the peak waveform of the generated output waveform as the position of the leading edge of the recording medium M. The detected position information is stored in a memory area such as the RAM 408 as position information of the leading edge of the recording medium M. Thus, in this embodiment, the first sensor 202 and the CPU 404 function as a detection unit that detects the recording medium M and, based on the results of the detection, detects the position of the recording medium M.

[0079] =Detection of the rear end of recording medium M= Next, the detection of the rear end of the recording medium M, performed in S526, will be described. In S526, while the recording medium M is transported in the +Y direction, the change in the differential signal Vout based on the output voltages of the first light receiving unit 802 and the second light receiving unit 804 is acquired, and the position of the rear end of the recording medium M is detected based on this change.

[0080] • Changes in output voltage VA, output voltage V / A, and differential signal Vout This section describes the changes in output voltage VA, output voltage V / A, and differential signal Vout in the detection circuit 900 when detecting the rear end of the recording medium M. Figure 13 illustrates the changes in output voltage by the two light-receiving units and the changes in the differential signal by the differential amplifier when detecting the rear end of the recording medium M. Figure 13(a) is an output waveform showing the change in output voltage VA according to the amount of light received by the first light-receiving unit 802. Figure 13(b) is an output waveform showing the change in output voltage V / A according to the amount of light received by the second light-receiving unit 804. Figure 13(c) is an output waveform showing the change in the differential signal Vout. Figure 14 is a diagram showing the position of the light-receiving member 214 relative to the recording medium M being transported. Note that in Figure 14, some of the components of the recording unit 14 are omitted for ease of understanding. Also, in Figure 14, the rear end of the recording medium M is indicated as "EB".

[0081] First, let's explain the change in output voltage VA. In the first sensor 202, the recording medium M being transported in the transport direction gradually moves away from the light-receiving area of ​​the first light-receiving unit 802, which is located upstream in the transport direction (+Y direction). As the proportion of the light-receiving area of ​​the first light-receiving unit 802 decreases, the amount of light received by the first light-receiving unit 802 decreases, and in accordance with this decrease, the photocurrent Id decreases, causing the output voltage VA from the IV conversion circuit 904 to drop (see Figure 13(a)). Subsequently, when the recording medium M has completely moved away from the light-receiving area of ​​the first light-receiving unit 802, and only the platen 24 is located in that light-receiving area, the photocurrent Id stops flowing in the detection circuit 900, and the output voltage VA maintains its minimum value, i.e., 0V. Therefore, the change in output voltage VA when detecting the trailing end of the recording medium M is as shown in the output waveform 1302.

[0082] Next, the change in the output waveform V / A will be explained. After the recording medium M has completely moved away from the light-receiving area of ​​the first light-receiving unit 802, as the recording medium M is further transported in the transport direction, the recording medium M gradually moves away from the light-receiving area of ​​the second light-receiving unit 804. As the proportion of the recording medium M in the light-receiving area of ​​the second light-receiving unit 804 decreases, the amount of light received by the first light-receiving unit 802 decreases, and in accordance with this decrease, the photocurrent Id' decreases, and the output voltage V / A from the IV conversion circuit 906 increases (see Figure 13(b)). Subsequently, when the recording medium M has completely moved away from the light-receiving area of ​​the second light-receiving unit 804, and only the platen 24 is located in that light-receiving area, the photocurrent Id' stops flowing in the detection circuit 900, and the output voltage V / A maintains its maximum value, i.e., 0V. Therefore, the change in the output voltage V / A when detecting the trailing end of the recording medium M is as shown in the output waveform 1304.

[0083] Next, the change in the differential signal Vout will be explained. When the trailing end of the recording medium M is detected, the output voltage VA decreases from the peak value of the positive electrode in accordance with the decrease in the amount of light received by the first light receiving unit 802 (see Figure 13(a)). On the other hand, the output voltage V / A increases from the peak value of the negative electrode in accordance with the decrease in the amount of light received by the first light receiving unit 802 (see Figure 13(b)).

[0084] Therefore, when only the recording medium M is located in the light-receiving area of ​​the first light-receiving unit 802 and the light-receiving area of ​​the second light-receiving unit 804 (see Figure 14(a)), the output voltage VA becomes the peak value of the positive electrode, and the output voltage V / A becomes the peak value of the negative electrode. As a result, the differential signal Vout becomes the sum of the peak value of the positive electrode and the peak value of the negative electrode, resulting in 0V (see area S6 in Figure 13(c)).

[0085] As the transport of the recording medium M progresses and the recording medium M begins to recede from the light-receiving area of ​​the first light-receiving unit 802, and the proportion of the light-receiving area occupied by the recording medium M decreases (see Figure 14(b)), the second light-receiving unit 804 has only the recording medium M located in its light-receiving area. Therefore, at this time, the output voltage VA decreases from the peak value of the positive electrode, and the output voltage V / A maintains the peak value of the negative electrode, decreasing in accordance with the decrease in the differential signal Voutha and output voltage VA (see area S7 in Figure 13(c)).

[0086] As the transport of the recording medium M progresses further, and the rear end of the recording medium M is positioned between the light-receiving area of ​​the first light-receiving unit 802 and the light-receiving area of ​​the second light-receiving unit 804 in the Y direction (see Figure 14(c)), the platen 24 is positioned over the entire light-receiving area of ​​the first light-receiving unit 802. Also, the recording medium M is positioned over the entire light-receiving area of ​​the second light-receiving unit 804. Therefore, at this time, the output voltage VA maintains 0V, the output voltage V / A maintains the peak value of the negative terminal, and the differential signal Vout maintains the peak value of the negative terminal (see area S8 in Figure 13(c)).

[0087] As the transport of the recording medium M progresses further, and the recording medium M begins to recede from the light-receiving area of ​​the second light-receiving unit 804, and the proportion of the light-receiving area occupied by the recording medium M decreases (see Figure 14(d)), only the platen 24 is located in the light-receiving area of ​​the first light-receiving unit 802. Therefore, at this time, the output voltage VA remains at 0V, the output voltage V / A rises from the peak value of the negative terminal, and the differential signal Vout rises in accordance with the rise in output voltage V / A (see area S9 in Figure 13(c)).

[0088] As the transport of the recording medium M progresses further, and the recording medium M is completely removed from the light-receiving area of ​​the second light-receiving unit 804 (see Figure 14(e)), the recording medium M is also completely removed from the light-receiving area of ​​the first light-receiving unit 802. Therefore, at this time, both the output voltage VA and the output voltage V / A become 0V, and the differential signal Vout becomes 0V. Consequently, the change in the differential signal Vout when detecting the trailing end of the recording medium M is as shown in output waveform 1306.

[0089] • Method for detecting the rear end position of recording medium M Next, a method for detecting the rear end position of the recording medium M based on the differential signal Vout will be described. When detecting the rear end of the recording medium M, the peak value of the differential signal Vout will be a value corresponding to the output voltage V / A, and therefore will change depending on the reflectivity of the recording medium M (type of recording medium M). Although not shown in the diagram, for example, the peak value of the differential signal Vout when detecting the rear end of glossy paper with high reflectivity will be larger (larger towards the negative terminal) than the peak value of the differential signal Vout when detecting the rear end of plain paper, gray paper, and other types of paper.

[0090] However, the output waveform of the differential signal Vout, similar to when detecting the leading edge of the recording medium M, shows that even if the peak value changes depending on the type of recording medium M, the width of the peak waveform remains almost unchanged, and the center position Pc of the peak waveform is approximately It does not change. Therefore, regardless of the type of recording medium M, the center position Pc of the peak waveform in the output waveform showing the change in the differential signal Vout corresponds to the rear end of the recording medium M.

[0091] Therefore, in S526, the CPU 404 converts the differential signal Vout input to the A / D converter into digital data and generates an output waveform that shows the change in the differential signal Vout. Then, the center position Pc of the peak waveform of the generated output waveform is detected as the position of the rear end of the recording medium M. The detected center position Pc is stored in a memory area such as RAM 408 as the position information of the rear end of the recording medium M.

[0092] <Detection of the X-direction edge of recording medium M> Next, the detection of the end ER and end EL of the recording medium M by the first sensor 202 will be described.

[0093] =First light-receiving section and second light-receiving section= The first light-receiving unit 702 and the second light-receiving unit 704, which detect the edges ER and EL of the recording medium M, are set based on the selection pattern selected in S510, S514, S518, or S520.

[0094] For example, suppose selection pattern 2 is selected in S514. In this case, the CPU 404, via the selector 902 in the detection circuit 900, sets two adjacent photodetectors 300 located on the other side of the center position in the X direction of the PD array 302c to function as the first photodetector 702. The CPU 404 also, via the selector 902 in the detection circuit 900, sets two adjacent photodetectors 300 located on one side of the center position in the X direction of the PD array 302c to function as the second photodetector 704 (see Figure 7(b)).

[0095] =Detection of the end ER of the recording medium M= Next, the detection of the edge ER of the recording medium M, which is performed in S524, will be described. In S524, with the recording medium M positioned so that its edges ER and EL can be detected by the first sensor 202 moving in the X direction via the carriage 22, the edge ER of the recording medium M is detected while the first sensor 202 is moved in the +X direction. Specifically, while moving the first sensor 202 in the +X direction, the change in the differential signal Vout based on the output voltages of the first light receiving unit 702 and the second light receiving unit 704 is acquired, and the position information of one side of the edge ER of the recording medium M is detected based on this change.

[0096] • Changes in output voltage VA, output voltage V / A, and differential signal Vout This section describes the changes in the output voltage VA, output voltage V / A, and differential signal Vout in the detection circuit 900 when detecting the end ER of the recording medium M. Figure 15 illustrates the changes in the output voltage by the two light receiving units and the changes in the differential signal by the differential amplifier when detecting the end ER of the recording medium M. Figure 15(a) shows the output waveform showing the change in output voltage VA by the first light receiving unit 702, the output waveform showing the change in output waveform V / A by the second light receiving unit 704, and the output waveform showing the change in differential signal Vout, based on selection pattern 1. Figure 15(b) shows the output waveform showing the change in output voltage VA by the first light receiving unit 702, the output waveform showing the change in output waveform V / A by the second light receiving unit 704, and the output waveform showing the change in differential signal Vout, based on selection pattern 2. Figure 15(c) shows the output waveform showing the change in output voltage VA by the first light receiving unit 702, the output waveform showing the change in output waveform V / A by the second light receiving unit 704, and the output waveform showing the change in differential signal Vout, based on selection pattern 3. Figure 15(d) shows the output waveforms indicating the change in output voltage VA by the first light receiving unit 702, the output waveform indicating the change in output waveform V / A by the second light receiving unit 704, and the output waveform indicating the change in the differential signal Vout, based on selection pattern 4.

[0097] Figure 16 shows the position of the light-receiving member 214 relative to the recording medium M. Note that in Figure 16, some of the components of the recording unit 14 are omitted for ease of understanding. Also, since Figures 15(a) to 15(d) show the case where the edge ER of the same type of recording medium M is detected, the peak waveform in each output waveform becomes larger as the number of light-receiving elements in the light-receiving unit increases. Note that in Figure 15, the arrows shown above the light-receiving units 702 and 704 indicate the relative direction of movement of the recording medium M with respect to the first sensor 202.

[0098] First, let's explain the change in output voltage VA. In the first sensor 202, when the recording medium M enters the light-receiving area of ​​the first light-receiving unit 702 located downstream in the direction of movement (+X direction), a photocurrent Id begins to flow in the detection circuit 900. As the first sensor 202 moves, the proportion of the recording medium M that occupies the light-receiving area increases, the amount of light received by the first light-receiving unit 702 increases, and in accordance with this increase, the photocurrent Id increases, causing the output voltage VA from the IV conversion circuit 904 to rise. Subsequently, when only the recording medium M is located in the light-receiving area of ​​the first light-receiving unit 702, the output voltage VA maintains its positive electrode peak value. Therefore, the change in output voltage VA when detecting the edge ER of the recording medium M is as shown in the output waveform OW1 (see Figures 15(a) to (d)).

[0099] Next, the change in output voltage V / A will be explained. When the recording medium M is positioned within the entire light-receiving area of ​​the first light-receiving unit 702, and the first sensor 202 is moved further in the direction of movement, the recording medium M enters the light-receiving area of ​​the second light-receiving unit 704. When the recording medium M enters the light-receiving area of ​​the second light-receiving unit 704, a photocurrent Id' begins to flow in the detection circuit 900. As the proportion of the recording medium M that occupies the light-receiving area increases due to further movement of the first sensor 202, the amount of light received by the second light-receiving unit 704 increases, and in accordance with this increase, the photocurrent Id' increases, and the output voltage V / A from the IV conversion circuit 906 decreases. Subsequently, when only the recording medium M is positioned within the light-receiving area of ​​the second light-receiving unit 704, the output voltage V / A maintains the peak value of the negative electrode. Therefore, the change in output voltage V / A when detecting the edge ER of the recording medium M is as shown in the output waveform OW2 (see Figures 15(a) to (d)).

[0100] Next, we will explain the change in the differential signal Vout. When detecting the edge ER of the recording medium M, the output voltage VA increases from 0V in accordance with the increase in the amount of light received by the first light receiving unit 702 (see output waveform OW1 in Figure 15). On the other hand, the output voltage V / A decreases from 0V in accordance with the increase in the amount of light received by the second light receiving unit 704 (see output waveform OW2 in Figure 15).

[0101] Therefore, when the recording medium M is not located in the light-receiving area of ​​the first light-receiving unit 702 or the light-receiving area of ​​the second light-receiving unit 704 (see Figure 16(a)), the first light-receiving unit 702 and the second light-receiving unit 704 do not receive reflected light, or receive very little light. Consequently, in this case, both the output voltage VA and the output voltage V / A become 0V, and the differential signal Vout becomes 0V (see area A1 in Figure 15).

[0102] As the first sensor 202 moves, the recording medium M begins to enter the light-receiving area of ​​the first light-receiving unit 702, and the proportion of the light-receiving area occupied by the recording medium M increases (see Figure 16(b)). At this time, the platen 24 of the second light-receiving unit 704 is positioned in that light-receiving area. Consequently, at this time, the output voltage VA rises from 0V, the output voltage V / A remains at 0V, and the differential signal Vout rises in accordance with the rise in output voltage VA (see area A2 in Figure 15).

[0103] As the movement of the first sensor 202 progresses further, and the recording medium M begins to enter the light-receiving area of ​​the second light-receiving unit 704, and the proportion of the light-receiving area occupied by the recording medium M increases (see Figure 16(c)), the first light-receiving unit 702 will have only the recording medium M located in its light-receiving area. Therefore, at this time, the output voltage VA maintains the peak value of the positive electrode, the output voltage V / A decreases from 0V, and the differential signal Vout decreases in accordance with the decrease in output voltage V / A (see area A3 in Figure 15).

[0104] As the first sensor 202 moves further, and the recording medium M is positioned within the entire light-receiving area of ​​the second light-receiving unit 704 (see Figure 16(d)), the recording medium M is also positioned within the entire light-receiving area of ​​the first light-receiving unit 702. Therefore, at this time, the output voltage VA maintains the peak value of the positive terminal, the output voltage V / A maintains the peak value of the negative terminal, and the differential signal Vout becomes 0V (see area A4 in Figure 15). Consequently, the change in the differential signal Vout when detecting the end ER of the recording medium M is as shown in the output waveform OW3 (see Figures 15(a) to (d)).

[0105] • Detection of the position of the end ER of the recording medium M Next, a method for detecting the position of the edge ER of the recording medium M based on the differential signal Vout will be described. Similar to the detection of the tip position, the center position Pc of the width of the peak waveform of the output waveform is detected. The position information of the detected center position Pc is then stored in the memory area as the position information of the edge EL of the recording medium M. Note that the method for detecting the center position Pc is not limited to this. When detecting the edge ER of the recording medium M, the number of photodetectors constituting the first photodetector 702 and the second photodetector 704 is selected according to the type of recording medium M. Therefore, the peak value of the differential signal Vout becomes larger than a predetermined value. That is, the number of photodetectors constituting the first photodetector 702 and the second photodetector 704 is adjusted so that the peak value of the differential signal Vout becomes larger than a predetermined value. Accordingly, when detecting the center position Pc, the position where the value of the differential signal Vout exceeds a preset threshold (a value smaller than the predetermined value) and the position where it falls below the threshold may be obtained, and the position between these two may be detected as the center position Pc.

[0106] =Detection of the edge EL of the recording medium M= Next, the detection of the end EL of the recording medium M, performed in S524, will be described. In S524, with the recording medium M positioned so that its ends ER and EL can be detected by the first sensor 202 moving in the X direction via the carriage 22, the end EL of the recording medium M is detected while the first sensor 202 is moved in the -X direction. Specifically, while moving the first sensor 202 in the -X direction, the change in the differential signal Vout based on the output voltages of the first light receiving unit 702 and the second light receiving unit 704 is acquired, and the position information of the other end EL of the recording medium M is acquired based on this change. Note that in S524, the execution order of the detection of the end ER and the end EL of the recording medium M may be either the detection of the end ER followed by the detection of the end EL, or vice versa.

[0107] • Changes in output voltage VA, output voltage V / A, and differential signal Vout This section describes the changes in output voltage VA, output voltage V / A, and differential signal Vout in the detection circuit 900 when detecting the edge EL of the recording medium M. Figure 17 illustrates the changes in output voltage by the two light-receiving units and the changes in the differential signal by the differential amplifier when detecting the edge EL of the recording medium M. Figure 17(a) shows the output waveforms showing the change in output voltage VA by the first light-receiving unit 702, the output waveform showing the change in output voltage V / A by the second light-receiving unit 704, and the output waveform showing the change in differential signal Vout, based on selection pattern 1. Figure 17(b) shows the output waveforms showing the change in output voltage VA by the first light-receiving unit 702, the output waveform showing the change in output voltage V / A by the second light-receiving unit 704, and the output waveform showing the change in differential signal Vout, based on selection pattern 2. Figure 17(c) shows the output waveforms showing the change in output voltage VA by the first light-receiving unit 702, the output waveform showing the change in output voltage V / A by the second light-receiving unit 704, and the output waveform showing the change in differential signal Vout, based on selection pattern 3. Figure 17(d) shows the output waveforms indicating the change in output voltage VA by the first light receiving unit 702, the output waveform indicating the change in output voltage V / A by the second light receiving unit 704, and the output waveform indicating the change in the differential signal Vout, based on selection pattern 4.

[0108] Figure 18 shows the position of the light-receiving member 214 relative to the recording medium M. Note that in Figure 18, some of the components of the recording unit 14 are omitted for ease of understanding. Also, since Figures 17(a) to 17(d) show the case of detecting the edge EL of the same type of recording medium M, the peak waveform in each output waveform becomes larger as the number of light-receiving elements in the light-receiving unit increases. Note that in Figure 17, the arrows shown above the light-receiving units 702 and 704 indicate the relative direction of movement of the recording medium M with respect to the first sensor 202.

[0109] First, let's explain the change in output voltage V / A. In the first sensor 202, when the recording medium M enters the light-receiving area of ​​the second light-receiving unit 704, which is located downstream in the direction of movement (-X direction), a photocurrent Id' begins to flow in the detection circuit 900. As the first sensor 202 moves, the proportion of the recording medium M that occupies the light-receiving area increases, the amount of light received by the second light-receiving unit 704 increases, and in accordance with this increase, the photocurrent Id' increases, causing the output voltage V / A from the IV conversion circuit 906 to decrease. Subsequently, when only the recording medium M is located in the light-receiving area of ​​the second light-receiving unit 704, the change in output voltage V / A maintains the peak value of the negative electrode. Therefore, the output voltage V / A when detecting the edge EL of the recording medium M will be as shown in the output waveform OW4 (see Figures 17(a) to (d)).

[0110] Next, the change in output voltage VA will be explained. When the recording medium M is positioned within the entire light-receiving area of ​​the second light-receiving unit 704, and the first sensor 202 is moved further in the moving direction, the recording medium M enters the light-receiving area of ​​the first light-receiving unit 702. When the recording medium M enters the light-receiving area of ​​the first light-receiving unit 702, a photocurrent Id begins to flow in the detection circuit 900. As the first sensor 202 moves further, the proportion of the recording medium M that occupies the light-receiving area increases, the amount of light received by the first light-receiving unit 702 increases, and in accordance with this increase, the photocurrent Id increases, and the output voltage VA from the IV conversion circuit 904 increases. Subsequently, when only the recording medium M is positioned within the light-receiving area of ​​the first light-receiving unit 702, the output voltage VA maintains the peak value of the positive electrode. Therefore, the change in output voltage VA when detecting the edge EL of the recording medium M is as shown in the output waveform OW5. (See Figures 17(a) to (d)).

[0111] Next, we will explain the change in the differential signal Vout. When detecting the edge EL of the recording medium M, the output voltage V / A decreases from 0V in accordance with the increase in the amount of light received by the second light receiving unit 704 (see output waveform OW4 in Figure 15). On the other hand, the output voltage VA increases from 0V in accordance with the increase in the amount of light received by the first light receiving unit 702 (see output waveform OW5 in Figure 15).

[0112] Therefore, when the recording medium M is not located in the light-receiving area of ​​the first light-receiving unit 702 or the light-receiving area of ​​the second light-receiving unit 704 (see Figure 18(a)), the first light-receiving unit 702 and the second light-receiving unit 704 do not receive reflected light, or receive very little light. Consequently, in this case, both the output voltage V / A and the output voltage VA become 0V, and the differential signal Vout becomes 0V (see area A5 in Figure 17).

[0113] As the first sensor 202 moves, the recording medium M begins to enter the light-receiving area of ​​the second light-receiving unit 704, and the proportion of the light-receiving area occupied by the recording medium M increases (see Figure 18(b)). At this time, the platen 24 of the first light-receiving unit 702 is positioned in that light-receiving area. Consequently, at this time, the output voltage V / A decreases from 0V, the output voltage VA remains at 0V, and the differential signal Vout decreases in accordance with the decrease in output voltage V / A (see area A6 in Figure 17).

[0114] As the movement of the first sensor 202 progresses further, and the recording medium M begins to enter the light-receiving area of ​​the first light-receiving unit 702, and the proportion of the light-receiving area occupied by the recording medium M increases (see Figure 18(c)), the second light-receiving unit 704 will have only the recording medium M located in its light-receiving area. Therefore, at this time, the output voltage V / A maintains its negative peak value, the output voltage VA rises from 0V, and the differential signal Vout rises in accordance with the rise in output voltage VA (see area A7 in Figure 17).

[0115] As the first sensor 202 moves further, and the recording medium M is positioned across the entire light-receiving area of ​​the first light-receiving unit 702 (see Figure 18(d)), the recording medium M is also positioned across the entire light-receiving area of ​​the second light-receiving unit 704. Therefore, at this time, the output voltage V / A maintains its negative peak value, the output voltage VA maintains its positive peak value, and the differential signal Vout becomes 0V (see area A8 in Figure 17). Consequently, the change in the differential signal Vout when detecting the edge EL of the recording medium M is as shown in the output waveform OW6.

[0116] • Detection of the position of the end EL of the recording medium M Next, a method for detecting the position of the edge EL of the recording medium M based on the differential signal Vout will be described. Similar to detecting the tip position, the center position Pc of the width of the peak waveform of the output waveform is detected. The position information of the detected center position Pc is then stored in a storage area such as RAM 408 as the position information of the edge EL of the recording medium M. Note that the method for detecting the center position Pc is not limited to this. When detecting the edge EL of the recording medium M, the number of photodetectors constituting the first photodetector 702 and the second photodetector 704 is selected according to the type of recording medium M. For this reason, the peak value of the differential signal Vout becomes larger than a predetermined value. Therefore, when detecting the center position Pc, the position where the value of the differential signal Vout exceeds a preset threshold (a value smaller than the predetermined value) and the position where it falls below the threshold may be obtained, and the intermediate position between these may be detected as the center position Pc.

[0117] <Cash register adjustment> Next, the detection of the position detection patch during register adjustment will be explained. The recording device 10 is equipped with a register adjustment function to adjust for any misalignment of the ink landing position by the recording head 20. During register adjustment, a register adjustment pattern (register adjustment pattern) is recorded on the recording medium, then the recording medium is pulled back (transported in the -Y direction), and then transported again in the transport direction (+Y direction), and the register adjustment pattern is read by the second sensor 204. In some cases, the register adjustment pattern is recorded on both sides of the recording medium, and the transport and pull-back of the recording medium are repeatedly performed. As a result, when the second sensor 204 detects (reads) the register adjustment pattern, the position of the recording medium may shift in the X direction, and in this case, accurate register adjustment cannot be performed.

[0118] Therefore, in this embodiment, when recording the register adjustment pattern, multiple position detection patches are recorded on the downstream side of the transport direction in the recording medium when the register adjustment pattern is read by the second sensor 204. Then, during register adjustment, the first sensor 202 detects the position detection patches.

[0119] =Position detection patch= Figure 19 shows a position detection patch according to this embodiment. The position detection patch 1902 in Figure 19 is recorded on the recording medium M downstream in the transport direction (+Y direction) relative to the register adjustment pattern 1904. In this embodiment, three position detection patches 1902a, 1902b, and 1902c are arranged along the X direction, and each position detection patch 1902 is arranged with a predetermined interval between adjacent position detection patches. The predetermined interval is, for example, longer than the length of the position detection patch 1902 in the X direction. Also, each position detection patch 1902 is, for example, a solid black square.

[0120] If the register adjustment pattern 1904 does not fit on one side of the recording medium M during register adjustment, the portion of the register adjustment pattern 1904 that could not be recorded on one side is recorded on the other side of the recording medium M. At this time, a position detection patch 1902 is recorded on the other side, downstream of the register adjustment pattern 1904 in the transport direction. The position detection patch 1902 is used to read the position of the recording medium M before reading the register adjustment pattern 1904 recorded on the recording medium M. The position detection patch 1902 is also used as a reference position for understanding the contents of each patch of the register adjustment pattern 1904. Note that the number of position detection patches 1902 is not limited to three, but may be two or four or more. Also, although the position detection patch 1902 is shown as solid black, it is not limited to this, and may be other colors or patterns as long as the difference in reflectivity with the unrecorded recording medium M is large.

[0121] =Detection of position detection patch= Next, the detection of the position detection patch will be described. When recording the position detection pattern together with the register adjustment pattern, as a pre-processing step for the recording, the light-receiving elements 300 that form the first light-receiving section 702 and the second light-receiving section 704 in the first sensor 202 are set based on the type of recording medium M. The setting of the light-receiving elements 300 of the first light-receiving section 702 and the second light-receiving section 704 based on the type of recording medium M is the same as described in the recording process above, so that explanation will be omitted.

[0122] In this embodiment, the recording medium M is positioned so that the recorded position detection patch 1902 can be detected by the first sensor 202 which moves in the X direction via the carriage 22. The position detection patch 1902 is detected while the first sensor 202 is moved in the +X direction. Specifically, while the first sensor 202 is moved in the +X direction, the change in the differential signal Vout based on the output voltages of the first light receiving unit 702 and the second light receiving unit 704 is acquired, and the position detection patch 1902 is detected based on this change.

[0123] • Changes in output voltage VA, output voltage V / A, and differential signal Vout This section describes the output voltage VA, output voltage V / A, and differential signal Vout in the detection circuit 900 when detecting the position detection patch 1902. Figure 20 illustrates the changes in output voltage by the two light receiving units and the changes in the differential signal by the differential amplifier when detecting the position detection patch 1902. Figure 20(a) shows the output waveform showing the change in output voltage VA by the first light receiving unit 702. Figure 20(b) shows the output waveform showing the change in output voltage V / A by the second light receiving unit 704. Figure 20(c) shows the output waveform showing the change in the differential signal Vout. In Figure 20, the arrows above the light receiving units 702 and 704 indicate the relative direction of movement of the recording medium M with respect to the first sensor 202.

[0124] First, let's explain the change in output voltage VA. In the first sensor 202, the position detection patch 1902 enters the light-receiving area of ​​the first light-receiving unit 702, which is located downstream in the direction of movement (+X direction). As the proportion of the light-receiving area occupied by the position detection patch 1902 increases, the amount of light received by the first light-receiving unit 702 decreases. In accordance with this decrease in the amount of light received, the photocurrent Id decreases, and the output voltage VA from the IV conversion circuit 904 decreases from the peak value of the positive electrode. Then, as the first sensor 202 moves further in the direction of movement, when only the position detection patch 1902 is located in the light-receiving area of ​​the first light-receiving unit 702, the output voltage VA will remain at 0V.

[0125] Subsequently, further movement of the first sensor 202 in the direction of movement causes the position detection patch 1902 to recede from the light-receiving area of ​​the first light-receiving unit 702, and the blank area of ​​the recording medium M enters. As the proportion of the blank area in the light-receiving area increases, the amount of light received by the first light-receiving unit 702 increases. In response to this increase in the amount of light received, the photocurrent Id increases, and the output voltage VA rises. When only the blank area of ​​the recording medium M is located in the light-receiving area, the output voltage VA maintains its peak value at the positive electrode. Therefore, the change in output voltage VA when detecting the position detection patch is as shown in the output waveform 2002 (see Figure 20(a)).

[0126] Next, the change in output voltage V / A will be explained. In the first sensor 202, the position detection patch 1902 enters the light-receiving area of ​​the second light-receiving unit 704, which is located upstream in the direction of movement. As the proportion of the light-receiving area occupied by the position detection patch 1902 increases, the amount of light received by the second light-receiving unit 704 decreases. In accordance with this decrease in the amount of light received, the photocurrent Id' decreases, and the output voltage V / A from the IV conversion circuit 906 rises from the peak value of the negative terminal. Then, as the first sensor 202 moves further in the direction of movement, when only the position detection patch 1902 is located in the light-receiving area of ​​the second light-receiving unit 704, the output voltage V / A will remain at 0V.

[0127] Subsequently, as the first sensor 202 moves further in the direction of movement, the position detection patch 1902 retracts from the light-receiving area of ​​the second light-receiving unit 704, and a blank area of ​​the recording medium M enters. As the proportion of the blank area in the light-receiving area increases, the amount of light received by the second light-receiving unit 704 increases. In response to this increase in the amount of light received, the photocurrent Id' increases, and the output voltage V / A decreases. When only the blank area of ​​the recording medium M is located in the light-receiving area, the output voltage V / A maintains its negative peak value. Therefore, the change in output voltage V / A when detecting the position detection patch is as shown in the output waveform 2004 (see Figure 20(b)).

[0128] Next, the change in the differential signal Vout will be explained. When detecting the position detection patch 1902, the output voltage VA decreases from the peak value of the positive electrode in accordance with the decrease in the amount of light received by the first light receiving unit 702, reaches 0V, and then increases in accordance with the increase in the amount of light received by the first light receiving unit 702 (see Figure 20(a)). On the other hand, the output voltage V / A increases from the peak value of the negative electrode in accordance with the decrease in the amount of light received by the second light receiving unit 704, reaches 0V, and then decreases in accordance with the increase in the amount of light received by the second light receiving unit 704 (see Figure 20(b)). The change in the differential signal Vout is as shown in the output waveform 2006.

[0129] More specifically, when the position detection patch 1902 is not located in the light-receiving area of ​​the first light-receiving unit 702 or the light-receiving area of ​​the second light-receiving unit 704, that is, when only a blank area of ​​the recording medium M is located there, the first light-receiving unit 702 and the second light-receiving unit 704 receive a lot of reflected light. Therefore, in this case, the output voltage VA becomes the peak value of the positive electrode, the output voltage V / A becomes the peak value of the negative electrode, and the differential signal Vout becomes 0V (see area PA in Figure 20(c)).

[0130] When the first sensor 202 moves and the position detection patch 1902 begins to enter the light-receiving area of ​​the first light-receiving unit 702, and the proportion occupied by the position detection patch 1902 in that light-receiving area increases, the blank area of ​​the recording medium M is located in the light-receiving area of ​​the second light-receiving unit 704. Therefore, at this time, the output voltage VA decreases from the peak value of the positive terminal, the output voltage V / A maintains the peak value of the negative terminal, and the differential signal Vout decreases in accordance with the decrease in output voltage VA. Furthermore, when the first sensor 202 moves further and the position detection patch 1902 begins to enter the light-receiving area of ​​the second light-receiving unit 704, and the proportion occupied by the position detection patch in that light-receiving area increases, only the position detection patch is located in the light-receiving area of ​​the first light-receiving unit 702. Therefore, at this time, the output voltage VA remains at 0V, the output voltage V / A rises from the peak value of the negative terminal, and the differential signal Vout rises in accordance with the rise in output voltage V / A. In this way, when detecting one end of the position detection patch 1902, the change in the differential signal Vout forms a downward convex peak waveform (see region PB in Figure 20(c)).

[0131] Then, when the first sensor 202 moves and only the position detection patch 1902 is located in the light-receiving area of ​​the first light-receiving unit 702, and only the position detection patch 1902 is located in the light-receiving area of ​​the second light-receiving unit 704, the output voltage VA and output voltage V / A become 0V. Therefore, the differential signal Vout becomes 0V (see area PC in Figure 20(c)).

[0132] Furthermore, when the first sensor 202 moves and the position detection patch 1902 begins to retract from the light-receiving area of ​​the first light-receiving unit 702, and the proportion of the blank area of ​​the recording medium M in that light-receiving area increases, the position detection patch is located in the light-receiving area of ​​the second light-receiving unit 704. Therefore, at this time, the output voltage VA rises from 0V, the output voltage V / A remains at 0V, and the differential signal Vout rises in accordance with the rise in output voltage VA. Also, when the first sensor 202 moves further and the position detection patch 1902 begins to retract from the light-receiving area of ​​the second light-receiving unit 704, and the proportion of the blank area of ​​the recording medium M in that light-receiving area increases, only the blank area is located in the light-receiving area of ​​the first light-receiving unit 702. Therefore, at this time, the output voltage VA maintains the peak value of the positive electrode, the output voltage V / A falls from 0V, and the differential signal Vout falls in accordance with the fall in output voltage V / A. Thus, when detecting the other end of the position detection patch 1902, the change in the differential signal Vout forms an upward-convex peak waveform (see region PD in Figure 20(d)).

[0133] • Detection of the position of the position detection pattern Next, a method for detecting the position of the position detection patch 1902 based on the differential signal Vout will be described. Similar to detecting the position of the leading edge of the recording medium M, the center position Pc of the widths of the downward-convex peak waveform and the upward-convex peak waveform of the output waveform 2006 are detected as position information for both ends of the position detection patch 1902 in the X direction. The detected position information of the center position Pc is then stored in a storage area such as RAM 408 as position information for both ends of the position detection patch 1902. Since the length of the position detection patch 1902 in the X direction is set to be shorter than the distance between adjacent position detection patches, the downward-convex peak waveform and the upward-convex peak waveform corresponding to one position detection patch 1902 can be determined according to their respective lengths.

[0134] Furthermore, the center position Pc of the upward-convex peak waveform and the center position Pc of the downward-convex peak waveform The detection method is not limited to this. When detecting a position detection patch, the number of photodetectors 300 forming the first photodetector 702 and the second photodetector 704 is set according to the type of recording medium M. As a result, the peak value of the differential signal Vout is larger than a predetermined value (the difference from 0V is large). Therefore, when detecting the center position Pc, the position where the value of the differential signal Vout exceeds a preset threshold (a value where the difference from 0V is smaller than a predetermined value) and the position where it falls below that threshold are obtained, and the position midway between these is detected as the center position.

[0135] After detecting the position detection patch 1902, the drive unit 422 is controlled based on the position information of the detected position detection patch 1902 to transport the recording medium, while the register adjustment pattern 1904 is read by the second sensor 204 and register adjustment is performed.

[0136] <Effects and Effects> As described above, in this embodiment, the sensor for detecting the widthwise edge of the recording medium is equipped with two light-receiving units that receive reflected light from the recording medium M. The number of light-receiving elements constituting each light-receiving unit can be changed according to the type of recording medium M based on its light reflectivity, thereby changing the light-receiving area of ​​each light-receiving unit. As a result, when the reflectivity of the recording medium M is low, the amount of light received in each light-receiving unit can be increased by increasing the number of light-receiving elements constituting each light-receiving unit, thereby enabling accurate detection of the edge of the recording medium M.

[0137] Furthermore, the edges of the recording medium M and the edges of the position detection patch are detected based on the change in the differential signal generated by summing and amplifying the output voltage from one light-receiving unit and the output voltage from the other light-receiving unit. Therefore, it is possible to detect the positions of these edges without setting a threshold. Even if a threshold is set, by changing the light-receiving area according to the type of recording medium based on its reflectivity, the margin between the peak value and the threshold can be increased, thereby suppressing the effects of noise.

[0138] (Second Embodiment) Next, a recording device according to the second embodiment will be described with reference to Figures 21 to 23. In the following description, components that are the same as or equivalent to those in the recording device according to the first embodiment described above will be referred to with the same reference numerals as those used in the first embodiment described above, and their detailed explanation will be omitted.

[0139] The second embodiment differs from the first embodiment described above in that the number of light-receiving elements constituting the two light-receiving sections in the first sensor 202 is changed according to the distance between the recording medium M and the carriage 22. This will be explained in detail below.

[0140] Figure 21 illustrates the change in the spot area formed on the recording medium M by light emitted from the light-emitting member 212, depending on the thickness of the recording medium M. When cardboard CA is used as the recording medium M, the distance L1 between the bottom surface 22a of the carriage 22 facing the platen 24 and the recording medium M becomes shorter than the distance L2 between the bottom surface 22a and the recording medium M when ordinary paper RE is used as the recording medium M (see Figure 21). In this embodiment, ordinary paper is, for example, a recording medium with a thickness of about 0.09 mm, and cardboard is a recording medium that is thicker than ordinary paper by a predetermined range.

[0141] As a result, the spot area based on the light emitted from the light-emitting element 212 is larger on the regular paper RE, which is farther from the bottom surface 22a, than on the cardboard CA, which is closer to the bottom surface 22a. Therefore, the spot area 2102 based on the light emitted from the light-emitting element 212 on the cardboard CA, which is closer to the bottom surface 22a, is smaller than the spot area 2104 on the regular paper RE, which is further from the bottom surface 22a.

[0142] Therefore, when cardboard CA, which results in a relatively smaller spot area 2102, is used as the recording medium M, the area where reflected light is generated becomes smaller than when ordinary paper RE, which results in a relatively larger spot area 2104, is used as the recording medium M. For this reason, when cardboard CA is used as the recording medium M, there is a risk that the amount of light received by the two light-receiving parts of the light-receiving member 214 will be less than when ordinary paper RE is used as the recording medium M.

[0143] Therefore, in this embodiment, the number of photodetectors 300 in the two light-receiving sections is changed according to the type of recording medium M based on the distance from the bottom surface 22a to the recording medium M, that is, the thickness, which changes the size of the spot area. Specifically, the number of photodetectors 300 in each of the two light-receiving sections increases as the distance decreases, so that reflected light is received by more photodetectors in each light-receiving section, and the photocurrent generated by the reception of light in each light-receiving section is increased.

[0144] <Selection Pattern> This section describes the selection patterns associated with the types of recording media M based on reflectivity when using thick paper CA. Even with thick paper CA, there are different types of recording media M based on reflectivity. These types are classified into glossy paper (which has the highest reflectivity on the recording surface where ink is applied), plain paper (which has the next highest reflectivity after glossy paper), gray paper (which has the next highest reflectivity after plain paper), and others (which have the lowest reflectivity). Note that the selection patterns associated with the types of recording media M based on reflectivity when using regular paper RE are the same as in the first embodiment, so their explanation is omitted.

[0145] Figure 22 shows the combinations of photodetectors 300 that form the two light-receiving sections in each selectable selection pattern when using cardboard CA. Figure 22(a) shows selection pattern A, Figure 22(b) shows selection pattern B, Figure 22(c) shows selection pattern C, and Figure 22(d) shows selection pattern D.

[0146] In selection pattern A, which is selected when the type of recording medium M based on reflectivity is glossy paper, four photodetectors 300 located adjacent to each other at the center in the X direction of the PD arrays 302c and 302d are selected as two photodetectors each for the photodetector section. Specifically, in selection pattern A, two photodetectors are selected as the first photodetector section 702a: one photodetector located on the other side of the center in the X direction of the PD array 302c and one photodetector located on the other side of the center in the X direction of the PD array 302d. In addition, two photodetectors are selected as the second photodetector section 704a: one photodetector located on one side of the center in the X direction of the PD array 302c and one photodetector located on one side of the center in the X direction of the PD array 302d (see Figure 22(a)).

[0147] In selection pattern B, which is selected when the type of recording medium M based on reflectivity is plain paper, eight photodetectors 300 located adjacent to each other at the center in the X direction of the PD array 302c and PD array 302d are selected as four photodetectors each for the photodetector section. Specifically, in selection pattern B, four photodetectors—two located on the other side of the center position in the X direction of the PD array 302c and two located on the other side of the center position in the X direction of the PD array 302d—are selected as the first photodetector section 702b. In addition, four photodetectors—two located on one side of the center position in the X direction of the PD array 302c and two located on one side of the center position in the X direction of the PD array 302d—are selected as the second photodetector section 704b (see Figure 22(b)).

[0148] In selection pattern C, which is selected when the type of recording medium M based on reflectivity is gray paper, 12 photodetectors 300 located adjacent to each other at the center in the X direction of PD arrays 302c and 302d are selected as 6 elements each for the photodetector section. Specifically, in selection pattern C, 6 photodetectors are selected as the first photodetector section 702b, consisting of 3 photodetectors located on the other side of the center in the X direction of PD array 302c and 3 photodetectors located on the other side of the center in the X direction of PD array 302d. In addition, 6 photodetectors are selected as the second photodetector section 704b, consisting of 3 photodetectors located on one side of the center in the X direction of PD array 302c and 3 photodetectors located on one side of the center in the X direction of PD array 302d (see Figure 22(c)).

[0149] In selection pattern D, which is selected when the type of recording medium M based on reflectivity is "other," 16 photodetectors 300 located adjacent to each other at the center in the X direction of PD arrays 302c and 302d are selected, with 8 elements selected for each photodetector. Specifically, in selection pattern D, 8 photodetectors—four located on the other side of the center in the X direction of PD array 302c and four located on the other side of the center in the X direction of PD array 302d—are selected as the first photodetector 702b. Additionally, 8 photodetectors—four located on one side of the center in the X direction of PD array 302c and four located on one side of the center in the X direction of PD array 302d—are selected as the second photodetector 704b (see Figure 22(d)).

[0150] Thus, in selection patterns A to D, the number of photodetectors forming one light-receiving section differs depending on the type of recording medium M based on its reflectivity. More specifically, in selection patterns A to D, the number of photodetectors 300 forming one light-receiving section increases as the reflectivity of the recording medium decreases. The above-mentioned selection patterns A to D are stored in a memory area such as ROM 406, along with the above-mentioned selection patterns 1 to 4.

[0151] The number of photodetectors 300 forming one light-receiving section in each of the above selection patterns is merely an example. In each selection pattern, the number of photodetectors 300 can be any number, as long as the number of photodetectors 300 increases as the reflectivity of the recording medium decreases. When increasing the number of photodetectors 300, it is preferable to increase the number of photodetectors 300 along the direction of movement of the first sensor 202 relative to the recording bath medium, i.e., the X direction, but it is also possible to increase the number of photodetectors 300 in the Y direction. Furthermore, in each of the above selection patterns, the photodetectors of PD array 302c and PD array 302d are selected as the photodetectors forming one light-receiving section, but this is not the only option. As the photodetectors forming one light-receiving section, it is also possible to use photodetectors 300 from any two of the four PD arrays, such as PD array 302a and PD array 302b. Alternatively, it is also possible to use photodetectors 300 from three or more PD arrays. Furthermore, in each of the above-described selection patterns, the first light-receiving section 702 and the second light-receiving section 704 are formed without any gap between them, but the design is not limited to this. In each selection pattern, a gap of one or more light-receiving elements may be provided between the first light-receiving section 702 and the second light-receiving section 704.

[0152] <Recording process> In the above configuration, the recording device 10 performs a recording process to record data onto the recording medium M based on the input job. Figure 23 is a flowchart detailing the recording process performed by the recording device 10 according to this embodiment. The series of processes shown in the flowchart of Figure 23 are performed by the CPU 404 loading the program code stored in the ROM 406 into the RAM 408 and executing it. Alternatively, some or all of the functions of the steps in Figure 23 may be performed by hardware such as an ASIC or electrical circuit.

[0153] When the recording process begins, in S2302, the CPU 404 first determines whether or not the recording is to be done on cardboard. Specifically, the information set for the job includes the recording medium to be recorded on, and in S2302, based on this set information about the recording medium, the CPU 404 determines whether or not the recording medium to be recorded on is cardboard. If it is determined in S2302 that the recording is not to be done on cardboard, the process proceeds to S2304, where the CPU 404 executes the recording process for regular paper and then terminates this recording process. Note that the recording process for regular paper executed in S2304 is the same as the recording process described in the first embodiment above, so a detailed explanation is omitted.

[0154] In S2302, if it is determined that the recording is on cardboard, the process proceeds to S2306, where the CPU 404 feeds the recording medium M from the tray 16 or cassette and begins transporting it to the recording unit 14. In S2308, the CPU 404 lights up the light-emitting element 222 of the second sensor 204. Then, in S2310, the CPU 404 determines whether or not the second sensor 204 has detected the recording medium M. The specific processing content from S2304 to S2310 is the same as that described in S502 to S506 above, so a detailed explanation is omitted.

[0155] In S2310, if it is determined that the recording medium M has been detected, the process proceeds to S2312, where the CPU 404 determines, based on the detection result of the second sensor 204, whether or not the type of recording medium M is glossy paper. In S2312, if it is determined that the type of recording medium M is glossy paper, the process proceeds to S2314, where the CPU 404 selects selection pattern A as the selection pattern for the combination of light-receiving elements in the first light-receiving unit 702 and the second light-receiving unit 704, and proceeds to S2326, which will be described later. Here, although not shown in the diagram, a table is stored in a storage area such as the ROM 406, which associates the type of recording medium M and the selection pattern with the values ​​of data b1 / b0. Specifically, in this table, "1 / 1" in data b1 / b0 is associated with glossy paper and selection pattern A, and "1 / 0" in data b1 / b0 is associated with plain paper and selection pattern B. Furthermore, in the table, the "0 / 1" in data b1 / b0 is associated with gray paper and selection pattern C, and the "0 / 0" in data b1 / b0 is associated with other and selection pattern D.

[0156] Therefore, in S2312 and S2314, the determination is made by referring to this table based on the values ​​of the data b1 / b0 output from the discrimination circuit 600. That is, in S2312, the CPU 404 determines whether the data b1 / b0 output from the discrimination circuit 600 is "1 / 1". If the data b1 / b0 output from the discrimination circuit 600 is "1 / 1", the CPU 404 determines that the detected recording medium M is glossy paper. Also, in S2314, the CPU 404 selects selection pattern A, which corresponds to "1 / 1" in the data b1 / b0, in the table mentioned above.

[0157] Furthermore, in S2312, if it is determined that the type of recording medium M is not glossy paper, the process proceeds to S2316, where the CPU 404 determines whether or not the type of recording medium M is plain paper. In S2316, if it is determined that the type of recording medium M is plain paper, the process proceeds to S2318, where the CPU 404 selects selection pattern B as the selection pattern described above, and proceeds to S2326, which will be described later. That is, in S2316, it is determined whether or not the data b1 / b0 output from the discrimination circuit 600 is "1 / 0". If the data b1 / b0 output from the discrimination circuit 600 is "1 / 0", it is determined that it is plain paper. Also, in S2318, the CPU 404 selects selection pattern B, which is associated with "1 / 0" in the data b1 / b0 in the table described above.

[0158] Furthermore, in S2316, if it is determined that the type of recording medium M is not plain paper, the process proceeds to S2320, where the CPU 404 determines whether or not the type of recording medium M is gray paper. In S2320, if it is determined that the type of recording medium M is gray paper, the process proceeds to S2322, where the CPU 404 selects selection pattern C as the selection pattern described above, and proceeds to S2326, which will be described later. That is, in S2320, it is determined whether or not the data b1 / b0 output from the discrimination circuit 600 is "0 / 1". If the data b1 / b0 output from the discrimination circuit 600 is "0 / 1", it is determined that it is gray paper. Also, in S2322, the CPU 404 selects selection pattern C, which corresponds to the "0 / 1" of data b1 / b0 in the table described above.

[0159] Furthermore, if it is determined in S2320 that the type of recording medium M is not gray paper, the process proceeds to S2324, where the CPU 404 selects selection pattern D as the selection pattern described above, and proceeds to S2326, which will be described later. That is, in S2324, the CPU 404 selects selection pattern D, which corresponds to "0 / 0" in data b1 / b0 in the table described above.

[0160] Once the selection pattern is determined, in S2326, the CPU 404 detects the leading edge of the recording medium M. Next, in S2328, the CPU 404 detects the ends ER and EL in the width direction (X direction) of the recording medium M. Then, in S2330, the CPU 404 detects the trailing edge of the recording medium M. Finally, in S2332, the CPU 404 performs recording on the recording medium M. Once recording to the recording medium M is complete, in S2334, the CPU 404 determines whether or not to record on the next recording medium. If it is determined in S2334 to record on the next recording medium, the process returns to S2306. If it is determined in S2334 not to record on the next recording medium, this recording process ends. Note that the specific processing content from S2326 to S2334 is the same as that from S522 to S530 described above, so a detailed explanation is omitted.

[0161] <Effects and Effects> As described above, in this embodiment, the sensor for detecting the edge of the recording medium in the width direction is provided with two light-receiving units that receive reflected light from the recording medium M. Furthermore, the number of light-receiving elements constituting each light-receiving unit can be changed according to the type of recording medium M based on the reflectivity of light, thereby allowing the light-receiving area of ​​each light-receiving unit to be changed. In addition, the number of light-receiving elements constituting each light-receiving unit can be changed according to the type of recording medium M based on its thickness, thereby allowing the light-receiving area of ​​each light-receiving unit to be changed. As a result, in this embodiment, in addition to the effects of the first embodiment described above, even when using cardboard in the recording medium M, which results in a smaller spot area of ​​light from the light-emitting member, the amount of light received in each light-receiving unit can be secured, and the edge of the recording medium M can be accurately detected.

[0162] (Other embodiments) The embodiments described above may be modified as shown in (1) to (8) below.

[0163] (1) Although not specifically described in the above embodiment, the two sensors in the carriage 22 only need to be located upstream of the recording medium M in the transport direction (+Y direction) relative to the recording head 20, and their position in the width direction of the recording medium M is not limited. For example, in the carriage 22, one sensor may be provided on one side in the X direction and the other sensor may be provided on the other side in the X direction.

[0164] (2) In the above embodiment, the light-receiving elements constituting the first light-receiving unit 702 and the second light-receiving unit 704 are determined based on a selection pattern selected according to the type of recording medium M detected by the second sensor 204, but the embodiment is not limited to this. For example, the light-receiving elements may be determined according to the type of recording medium M set in the printer driver or the like. In this case, if the set type of recording medium M is glossy paper, selection pattern 1 is selected; if it is plain paper, selection pattern 2 is selected; if it is gray paper, selection pattern 3 is selected; and if it is anything else, selection pattern 4 is selected.

[0165] (3) In the first embodiment described above, the direction of movement of the first sensor 202 is different when detecting end ER and when detecting end EL, but the embodiment is not limited to this. For example, the first sensor 202 may be moved in the +X direction or the -X direction to detect the positions of both end ER and end EL. Also, in the first embodiment described above, end ER and EL are detected when the first sensor 202 enters the recording medium M, but the embodiment is not limited to this. End ER and EL may be detected when the first sensor 202 retracts from the recording medium M. Specifically in this case, end EL is detected while the first sensor 202 is moved in the +X direction, and end ER is detected while the first sensor 202 is moved in the -X direction.

[0166] (4) In the above embodiment, the detection circuit 900 is configured such that the positive voltage value VA based on the light received by the first light receiving unit 702 and the negative voltage value V / A based on the light received by the second light receiving unit 704 are input to the differential amplifier 908, but it is not limited to this. For example, the differential amplifier 908 may be configured such that the positive voltage value VA based on the light received by the first light receiving unit 702 is input, and the positive voltage value VA based on the light received by the second light receiving unit 704 is input. Alternatively, the differential amplifier 908 may be configured such that the negative voltage value V / A based on the light received by the first light receiving unit 702 is input, and the negative voltage value V / A based on the light received by the second light receiving unit 704 is input. In these cases, the differential amplifier 908 amplifies the difference between the two input voltage values ​​and outputs a differential signal Vout. Furthermore, in these cases, in order to increase the width of the peak waveform of the output waveform based on the change in the differential signal Vout, it is preferable to leave a gap between the photodetector constituting the first photodetector 702 and the photodetector constituting the second photodetector 704 in the X direction.

[0167] (5) In the second embodiment described above, the recording device 10 was described in which recording was performed on two types of recording media M based on thickness: thick paper CA and ordinary paper RE. However, the recording media M that can be recorded on by the recording device 10 are not limited to the two types described above. The recording device 10 may be configured to be able to record on three or more types of recording media M based on thickness. In this case, a selection pattern will be set for each type based on thickness, according to the type of recording media M based on reflectivity.

[0168] (6) In the above embodiment, the first sensor 202 is provided with a light-emitting member 212, but the invention is not limited thereto, and the light-emitting member 212 may be provided separately from the first sensor 202. Also, in the above embodiment, the recording device 10 is configured to record on the recording medium using a recording method that ejects ink, but the invention is not limited thereto, and various known technologies may be used as the recording method for the recording medium.

[0169] (7) The disclosure can also be implemented by supplying a program that implements one or more of the above embodiments to a system or device via a network or recording medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be implemented by a circuit (e.g., an ASIC) that implements one or more of the functions.

[0170] (8) The above embodiments and the various forms shown in (1) to (7) above may be combined as appropriate.

[0171] The above disclosure of embodiments includes the following configurations and methods. (Composition 1) A carriage is equipped with a recording head for recording onto a recording medium, and is movable in the width direction of the recording medium intersecting the transport direction of the recording medium, A detection means for detecting the recording medium by having one or more of the multiple light-receiving elements provided on the carriage function as a light-receiving unit, An acquisition means for acquiring information about the type of recording medium, A recording device characterized by having a setting means for setting a light-receiving element to function as a light-receiving unit based on the information acquired by the acquisition means. (Configuration 2) The recording device according to configuration 1, characterized in that the acquisition means acquires the information based on the amount of reflected light received from the recording medium from light irradiated onto the recording medium. (Composition 3) The recording device according to configuration 1, characterized in that the acquisition means acquires the input information. (Composition 4) The detection means comprises two light-receiving units, A recording device according to any one of configurations 1 to 3, characterized in that it acquires a change in signal based on the sum or difference of the outputs from the two light receiving units when the recording medium moves relative to the carriage. (Composition 5) The recording device according to configuration 1, characterized in that the information is information relating to the type of the recording medium based on its light reflectivity. (Composition 6) The recording apparatus according to configuration 5, characterized in that the setting means sets the light-receiving elements to function as light-receiving units such that the number of light-receiving elements to function as light-receiving units for the first recording medium is greater than the number of light-receiving elements to function as light-receiving units for the second recording medium having a higher reflectivity than the first recording medium. (Composition 7) The recording apparatus according to configuration 1, characterized in that the information is information relating to the type based on the thickness of the recording medium. (Composition 8) The recording apparatus according to configuration 7, characterized in that the setting means sets the light-receiving elements to function as light-receiving units such that the number of light-receiving elements to function as light-receiving units for the first recording medium is greater than the number of light-receiving elements to function as light-receiving units for the second recording medium which is thinner than the first recording medium. (Composition 9) The recording device according to configuration 4, characterized in that the detection means detects the position of the recording medium based on the change in the signal when it moves relative to the recording medium. (Composition 10) The recording device according to configuration 4, characterized in that the detection means detects the position of the patch based on the change in the signal when moving relative to the patch recorded on the recording medium. (Composition 11) The recording device according to configuration 10, further comprising means for reading patterns recorded in places other than the patch by the recording head, based on the position of the patch. (Composition 12) When detecting the end of the recording medium in the transport direction, the setting means: The light-receiving elements are configured such that the two light-receiving sections are formed at different positions in the transport direction. A recording device according to any one of configurations 4, 9, 10, and 11, characterized in that the two light-receiving elements that function as the two light-receiving units are the same regardless of the information. (Composition 13) When detecting the edge of the recording medium in the width direction or a patch recorded on the recording medium, the setting means: The light-receiving elements are configured such that the two light-receiving portions are formed at different positions in the width direction. A recording device according to any one of configurations 4, 9, 10, 11, and 12, characterized in that the number of light-receiving elements that function as light-receiving units for the first recording medium and the number of light-receiving elements that function as light-receiving units for the second recording medium are made different in the width direction based on the information. (Composition 14) The recording device according to any one of configurations 1 to 13, characterized in that the setting means sets the light-receiving elements based on a plurality of patterns in which the number of light-receiving elements to function as the light-receiving unit is different. (Composition 15) The recording device according to any one of configurations 4, 9, 10, 11, 12, and 13, characterized in that the detection means acquires positional information of the center position of the peak waveform in the output waveform showing the change in the signal. (Composition 16) A carriage is equipped with a recording head for recording onto a recording medium, and is movable in the width direction of the recording medium intersecting the transport direction of the recording medium, A control method for a recording device having detection means for detecting the recording medium by causing one or more of the multiple light-receiving elements provided on the carriage to function as a light-receiving unit, An acquisition step to acquire information regarding the type of recording medium, A control method characterized by comprising: a setting step of setting a light-receiving element to function as a light-receiving unit based on the information acquired in the acquisition step. [Explanation of Symbols]

[0172] 10 Recording device 20 Recording heads 22 Carriage 202 First Sensor 702, 704 Light receiving section 404 CPU

Claims

1. A carriage is equipped with a recording head for recording onto a recording medium, and is movable in the width direction of the recording medium intersecting the transport direction of the recording medium, A detection means for detecting the recording medium by having one or more of the multiple light-receiving elements provided on the carriage function as a light-receiving unit, An acquisition means for acquiring information about the type of recording medium, A recording device characterized by having a setting means for setting a light-receiving element to function as a light-receiving unit based on the information acquired by the acquisition means.

2. The recording apparatus according to claim 1, characterized in that the acquisition means acquires the information based on the amount of reflected light received from the recording medium from light irradiated onto the recording medium.

3. The recording device according to claim 1, characterized in that the acquisition means acquires the input information.

4. The detection means comprises two light-receiving units, The recording apparatus according to claim 1, characterized in that it acquires a change in signal based on the sum or difference of the outputs from the two light receiving units when the recording medium moves relative to the carriage.

5. The recording apparatus according to claim 1, characterized in that the information is information relating to the type of the recording medium based on its light reflectance.

6. The recording apparatus according to claim 5, characterized in that the setting means sets the light-receiving elements to function as light-receiving units such that the number of light-receiving elements to function as light-receiving units for the first recording medium is greater than the number of light-receiving elements to function as light-receiving units for the second recording medium having a higher reflectivity than the first recording medium.

7. The recording apparatus according to claim 1, characterized in that the information is information relating to the type based on the thickness of the recording medium.

8. The recording apparatus according to claim 7, characterized in that the setting means sets the light-receiving elements to function as light-receiving units such that the number of light-receiving elements to function as light-receiving units for the first recording medium is greater than the number of light-receiving elements to function as light-receiving units for the second recording medium which has a smaller thickness than the first recording medium.

9. The recording device according to claim 4, characterized in that the detection means detects the position of the recording medium based on the change in the signal when it moves relative to the recording medium.

10. The recording device according to claim 4, characterized in that the detection means detects the position of the patch based on the change in the signal when moving relative to the patch recorded on the recording medium.

11. The recording device according to claim 10, further comprising means for reading a pattern recorded in a location other than the patch by the recording head, based on the position of the patch.

12. When detecting the end of the recording medium in the transport direction, the setting means: The light-receiving elements are configured such that the two light-receiving sections are formed at different positions in the transport direction. The recording device according to claim 4, characterized in that the two light-receiving elements that function as the two light-receiving units are the same regardless of the information.

13. When detecting the edge of the recording medium in the width direction or a patch recorded on the recording medium, the setting means: The light-receiving elements are configured such that the two light-receiving portions are formed at different positions in the width direction. The recording apparatus according to claim 4, characterized in that the number of light-receiving elements that function as light-receiving units for the first recording medium and the number of light-receiving elements that function as light-receiving units for the second recording medium are made different in the width direction based on the information.

14. The recording device according to claim 1, characterized in that the setting means sets the light-receiving elements based on a plurality of patterns in which the number of light-receiving elements to function as the light-receiving unit is different.

15. The recording device according to claim 4, characterized in that the detection means acquires positional information of the center position of the peak waveform in the output waveform showing the change in the signal.

16. A carriage is equipped with a recording head for recording onto a recording medium, and is movable in the width direction of the recording medium intersecting the transport direction of the recording medium, A control method for a recording device having detection means for detecting the recording medium by causing one or more of the multiple light-receiving elements provided on the carriage to function as a light-receiving unit, An acquisition step to acquire information regarding the type of recording medium, A control method characterized by comprising: a setting step of setting a light-receiving element to function as a light-receiving unit based on the information acquired in the acquisition step.

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