Printing apparatus, method of controlling the same, and storage medium

Abstract

To provide a technique advantageous for improving detection accuracy of a position of a recording medium in a recording device.SOLUTION: According to an aspect of the present disclosure, a recording apparatus includes a recording unit configured to perform recording on a recording medium, a conveyance unit configured to convey the recording medium, and a position detection unit configured to detect a position of the recording medium. The position detector includes a light emitter that emits light to a conveyance path of the recording medium, a first light receiver that detects reflected light from the conveyance path, and a second light receiver that detects reflected light from the conveyance path and is arranged side by side with the first light receiver in a conveyance direction of the recording medium, and the position of the recording medium is identified based on a difference signal between a signal of the first light receiver and a signal of the second light receiver.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates primarily to a recording device. [Background technology]

[0002] Patent Document 1 describes a technology for detecting a recording medium using a light-emitting element and a light-receiving element in a recording device such as an inkjet printer. According to Patent Document 1, the light-emitting element irradiates light onto a transport path of the recording medium, and the reflected light is detected by the light-receiving element, thereby detecting the recording medium. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-182361 Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration of Patent Document 1, the signal value of the light receiving element may fluctuate depending on the state of the recording medium, such as its posture, and the environment, such as external light on the transport path, and there is room for improvement in terms of improving detection accuracy.

[0005] The present invention was made in response to the inventor's recognition of the above-mentioned problems, and has an object to provide a technique that is advantageous for improving the accuracy of detecting the position of a recording medium in a recording device. [Means for solving the problem]

[0006] One aspect of the present invention relates to a recording device, the recording device comprising: A recording apparatus comprising a recording unit for recording on a recording medium, a transport unit for transporting the recording medium, and a position detection unit for detecting the position of the recording medium, The position detection means a light emitting unit that irradiates light onto a transport path of the recording medium; a first light receiving unit that detects reflected light from the transport path; a second light receiving unit that detects reflected light from the transport path, the second light receiving unit being arranged alongside the first light receiving unit in the transport direction of the recording medium; the position of the recording medium is identified based on a differential signal between the signal from the first light receiving unit and the signal from the second light receiving unit. It is characterized by: [Effects of the Invention]

[0007] According to the present invention, it is possible to improve the accuracy of detecting the position of the recording medium. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing an example of the system configuration of a recording apparatus according to an embodiment. [Figure 2] FIG. 2 is a diagram showing a part of the internal structure of the recording apparatus. [Figure 3] FIG. 2 is a diagram for explaining an example of the configuration of a position detection unit. [Figure 4] 5A and 5B are diagrams for explaining the reflection mode of emitted light. [Figure 5] FIG. 4 is a diagram for explaining an example of a detection signal. [Figure 6] FIG. 2 is a diagram showing a configuration example of a differential signal output unit. [Figure 7] FIG. 4 is a diagram for explaining an example of a detection signal. [Figure 8] FIG. 4 is a diagram for explaining details of a detection signal. [Figure 9] FIG. 10 is a diagram for explaining an example of a configuration capable of generating an interrupt job. [Figure 10] FIG. 4 is a diagram for explaining a mode of generating an interrupt job. [Figure 11] 10 is a flowchart illustrating an example of a method for detecting the position of a recording medium. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the claimed invention. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0010] (Example of recording device configuration) 1 is a block diagram showing the system configuration of a recording apparatus 100 according to an embodiment. In this embodiment, the recording apparatus 100 includes a transport motor 104, a motor driver 105, a carriage motor 106, two or more encoder sensors 107, a head driver 108, and a recording head 109.

[0011] The recording device 100 further includes a differential signal output section 113 and a position detection unit 114. As will be described in detail later, the position detection unit 114 includes a light emitting section 110, a first light receiving section 111, and a second light receiving section 112, and the differential signal output section 113 is capable of outputting a signal corresponding to the difference between the signal from the light receiving section 111 and the signal from the light receiving section 112.

[0012] The recording device 100 further includes a main controller 101, a RAM (Random Access Memory) 102, and a ROM (Read Only Memory) 103. As will be described in detail later, the main controller 101 includes an input port 115, which can receive signals from the light receiving units 111 and 112.

[0013] 2 is a diagram showing a part of the internal structure of the recording apparatus 100. The recording apparatus 100 further includes an ink tank 1, an ink tank holder 2, a supply tube 6, a carriage 8, a transport roller 9, and a recovery unit .

[0014] A motor driver 105 controls the driving of the transport motor 104 and the carriage motor 106 individually. The transport roller 9 rotates upon receiving power from the transport motor 104 and transports the recording medium 11 in a predetermined direction (direction A in the figure). The carriage 8 is slidably installed along a guide rail extending in a direction substantially perpendicular to the transport direction of the recording medium 11, and receives power from the carriage motor 106 to move back and forth in one direction. A recording head 109 is detachably mounted on the carriage 8, and a position detection unit 114 is also attached to the carriage 8.

[0015] The two or more encoder sensors 107 are installed at corresponding positions within the recording device 100 . An encoder sensor 107a detects the amount of movement of the carriage 8. For example, a linear scale is provided on the guide rail, and the encoder sensor 107a outputs a signal for specifying the amount of movement of the carriage 8 based on this linear scale, thereby making it possible to specify the position of the carriage 8 and further the position of the print head 109. Another encoder sensor 107b detects the amount of rotation of the transport roller 9. For example, a rotary scale is provided on the transport roller 8, and the encoder sensor 107b outputs a signal for specifying the amount of rotation of the transport roller 9 based on this rotary scale, thereby making it possible to specify the transport amount of the recording medium 11 and further its position.

[0016] The print head 109 is provided with a plurality of nozzles (ink ejection ports), and ejects ink supplied from the ink tank 1 via the supply tube 6 from each nozzle based on a signal from a head driver 108. The print head 109 scans in one direction by the reciprocating movement of the carriage 8, and during this scan, performs printing by ejecting ink from each nozzle onto the print medium 11.

[0017] Recording here refers to forming an image using ink ejected onto the recording medium 11, and the concept of an image includes letters, numbers, symbols, figures, photographs, etc., as well as the blank space formed around them.

[0018] The ink tank 1 is replaceably attached to the ink tank holder 2, and when the remaining amount of ink falls below a certain level, the user can replace the ink tank 1 with another ink tank 1.

[0019] The main controller 101 is a system control unit that controls the entire system of the recording device 100. In this embodiment, the main controller 101 includes a CPU (Central Processing Unit) 702, which performs arithmetic processing for controlling the drive of the above-mentioned elements. A DRAM (Dynamic RAM) or the like is typically used for the RAM 102. A SSD (Solid State Drive) or the like is typically used for the ROM 103. For example, the CPU 702 reads a predetermined program from the ROM 103, and generates signals or data for implementing the functions of the recording device 100 while expanding the program and temporary data obtained by executing the program on the RAM 102.

[0020] The main controller 101 drives the transport motor 104 using the motor driver 105, thereby driving the transport roller 9 to transport the recording medium 11. The main controller 101 also drives the carriage motor 106 using the motor driver 105, thereby reciprocating the carriage 8 and causing the recording head 109 to scan. During the scanning of the recording head 109, the main controller 101 drives the recording head 109 using the head driver 108.

[0021] In this configuration, intermittent conveyance, in which the recording medium 11 is conveyed a predetermined distance and then the conveyance is suppressed, and scan recording, in which the recording head 109 is scanned while the conveyance is suppressed, are repeated to perform recording on the recording medium 11. Such a recording head 109 is referred to as a serial head. Because recording on the recording medium 11 is achieved by both the recording head 109 and the carriage 8, they may be collectively referred to as a recording unit.

[0022] The recovery unit 10 performs a recovery operation to restore the function of the recording head 109. For example, when the recording device 100 is started up or when a recording operation on the recording medium 11 is completed, the carriage 8 moves to the position where the recovery unit 10 is located, and the recording head 109 faces the recovery unit 10, and the recovery operation is performed accordingly.

[0023] (Example of a method for detecting recording media) As described above, the position detection unit 114 includes the light-emitting unit 110, the light-receiving unit 111, and the light-receiving unit 112. The light-emitting unit 110 can irradiate light (emitted light) onto the transport path of the recording medium 11. Furthermore, the light-receiving unit 111 and the light-receiving unit 112 can each detect light reflected by the transport path of the recording medium 11 (reflected light).

[0024] 3 is a diagram illustrating the configuration of the position detection unit 114. For ease of viewing, the light-emitting unit 110 is not shown. The light-receiving units 111 and 112 are arranged side by side along the transport direction of the recording medium 11. In other words, in a top view, the direction in which the light-receiving units 111 and 112 are arranged side by side and the direction in which the medium end surface 201 of the recording medium 11 extends are substantially perpendicular to each other.

[0025] For example, the light receiving unit 111 may include two or more light receiving elements in order to improve the detection accuracy of the reflected light from the transport path of the recording medium 11. Any known element may be used for each light receiving element, such as a photoelectric conversion element.

[0026] The light receiving unit 111 and the light receiving unit 112 are configured to achieve substantially the same performance. For example, if the light receiving unit 111 has two or more light receiving elements arranged at a predetermined interval in a predetermined direction, the light receiving unit 112 also has the same number of light receiving elements arranged at the same interval in the same direction. The two or more light receiving elements are arranged, for example, along the transport direction of the recording medium 11.

[0027] 4(a) and 4(b) are diagrams for explaining the reflection mode of the emitted light 301 of the light-emitting unit 110. As shown in Fig. 4(a), when the recording medium 11 is present at the irradiation destination of the emitted light 301, the reflected light is substantially light reflected by the recording medium 11. On the other hand, as shown in Fig. 4(b), when the recording medium 11 is not present at the irradiation destination of the emitted light 301, the reflected light is substantially light reflected by a platen 302 for supporting the recording medium 11 from the opposite side during recording by the recording head 109.

[0028] Since the recording medium 11 and the platen 302 have different optical reflectances, the amount of light reflected from the recording medium 11 differs from the amount of light reflected from the platen 302. In this embodiment, the amount of light reflected from the recording medium 11 is greater than the amount of light reflected from the platen 302.

[0029] 5(a1) to 5(c2), the detection signal of the light receiving section 111 will be described. The light receiving section 111 outputs a current of an amount corresponding to the amount of reflected light as a detection signal.

[0030] Fig. 5(a1) is a schematic side view of the light receiving unit 111 when no recording medium 11 is located in the detection area 403. Fig. 5(a2) shows the value of the detection signal of the light receiving unit 111 in the case of Fig. 5(a1). Since there is substantially no reflected light in Fig. 5(a1), the value of the detection signal of the light receiving unit 111 is substantially zero, as shown in Fig. 5(a2).

[0031] Fig. 5(b1) is a schematic side view of the recording medium 11 when a portion of the recording medium 11 is located in the detection area 403. Fig. 5(b2) shows the value of the detection signal of the light receiving unit 111 in the case of Fig. 5(b1). In Fig. 5(b1), reflected light 404 is generated, so the value of the detection signal of the light receiving unit 111 increases, as shown by waveform 406 in Fig. 5(b2).

[0032] Fig. 5(c1) is a schematic side view of the recording medium 11 when the entire recording medium 11 is positioned in the detection area 403. Fig. 5(c2) shows the value of the detection signal of the light receiving unit 111 in the case of Fig. 5(c1). In Fig. 5(c1), reflected light 405 is generated, which has a greater amount of light than reflected light 404, so the value of the detection signal of the light receiving unit 111 becomes even larger and then substantially reaches its maximum value, as shown by waveform 407 in Fig. 5(c2).

[0033] 5(a2), 5(b2), and 5(c2), as the recording medium 11 is conveyed by the conveying roller 9 and the overlapping area between the recording medium 11 and the detection area 403 increases, the value of the detection signal from the light receiving unit 111 increases. The same applies to the light receiving unit 112.

[0034] 6 is a diagram showing the configuration of the differential signal output unit 113. In this embodiment, the differential signal output unit 113 includes a differential amplifier circuit 502, a current-voltage conversion circuit 503, and a current-voltage conversion circuit 504. The current-voltage conversion circuit 503 performs current-voltage conversion on the current Id output from the light receiving unit 111, and outputs a voltage V A Similarly, the current-voltage conversion circuit 504 performs current-voltage conversion on the current Id′ output from the light receiving unit 112, and outputs the voltage V B The output voltage is V A and V B is input to the differential amplifier circuit 502.

[0035] The differential amplifier circuit 502 outputs a voltage V A and V B In this way, the differential signal output unit 113 outputs a differential signal between the detection signal of the light receiving unit 111 and the detection signal of the light receiving unit 112 as a voltage Vout.

[0036] The amplification factor of the differential amplifier circuit 502 may be a fixed value, or may be a variable value that can be adjusted by the main controller 101.

[0037] Figures 7(a1), 7(b1), and 7(c1) respectively show the light receiving units 111 and 112 for Figures 5(a1), 5(b1), and 5(c1). Figures 7(a2), 7(b2), and 7(c2) respectively show the detection signals of the light receiving units 111 and 112 in Figures 7(a1), 7(b1), and 7(c1), and the voltage Vout which is their differential signal.

[0038] FIG. 7(a1) shows a state when the recording medium 11 is not positioned in the detection area 601 of the light receiving unit 111 and a part of the recording medium 11 is positioned in the detection area 602 of the light receiving unit 112. In FIG. 7(a1), there is substantially no reflected light detected by the light receiving unit 111, but there is reflected light detected by the light receiving unit 112. Therefore, as shown in FIG. 7(a2), the value of the detection signal of the light receiving unit 111 (voltage V A ) is substantially zero, but the value of the detection signal of the light receiving unit 112 (voltage V B ) increases as shown by the waveform 603 in FIG. 7(a2). Accordingly, the voltage Vout, which is the differential signal, increases as shown by the waveform 604 in FIG. 7(a2).

[0039] FIG. 7(b1) shows a state when a portion of the recording medium 11 is located in the detection area 601 and the entire recording medium 11 is located in the detection area 602. In FIG. 7(b1), reflected light is generated and detected by the light receiving unit 111, and the amount of reflected light detected by the light receiving unit 112 further increases before reaching a substantially maximum value. Therefore, the value of the detection signal from the light receiving unit 111 increases as shown by waveform 606 in FIG. 7(b2), and the value of the detection signal from the light receiving unit 112 further increases as shown by waveform 605 in FIG. 7(b2) before reaching a substantially maximum value. Accordingly, the voltage Vout further increases, reaches a substantially maximum value, and then decreases as shown by waveform 607 in FIG. 7(b2).

[0040] FIG. 7(c1) shows a state when the entire recording medium 11 is positioned in each of the detection areas 601 and 602. In FIG. 7(c1), the amount of reflected light detected by the light receiving unit 112 has already reached substantially its maximum value, and the amount of reflected light detected by the light receiving unit 111 reaches substantially its maximum value later than the amount of reflected light detected by the light receiving unit 112. Therefore, the value of the detection signal from the light receiving unit 112 remains substantially at its maximum value as shown by waveform 608 in FIG. 7(c2), and the value of the detection signal from the light receiving unit 111 increases further before reaching substantially its maximum value as shown by waveform 609 in FIG. 7(c2). Accordingly, the voltage Vout decreases further to substantially zero as shown by waveform 610 in FIG. 7(c2).

[0041] Fig. 8 is a diagram for explaining the processing results of the detection signal, and is an enlarged diagram based on the waveform 610 of Fig. 7(c2). The horizontal axis in the diagram represents the time axis, and the vertical axis in the diagram represents the value of the voltage Vout. Time t10 corresponds to the timing when the voltage Vout starts to change from L level (low level) to H level (high level), and time t12 corresponds to the timing when the change is completed. Time t11 is any timing between times t10 and t12, and is the timing when the voltage Vout becomes the reference voltage Vref, as will be described in detail later. Time t20 corresponds to the timing when the voltage Vout starts to change from H level to L level, and time t22 corresponds to the timing when the change is completed. Time t21 is any timing between times t20 and t22, and is the timing when the voltage Vout becomes the reference voltage Vref, as will be described in detail later.

[0042] In this embodiment, the timing at which the position detection unit 114 detects the media end surface 201 of the recording medium 11 corresponds to time t15, which is the midpoint between times t11 and t21, thereby identifying the position of the recording medium 11. Here, the timing at which the position detection unit 114 should detect the medium end surface 201 may be determined based on the voltage Vout, which is a differential signal. Therefore, this timing may correspond to an intermediate timing between the time when the voltage Vout passes a predetermined value when changing from an L level to an H level and the time when the voltage Vout passes the same value when changing from an H level to an L level. Therefore, in other embodiments, this timing may correspond to an intermediate timing between times t10 and t22, or an intermediate timing between times t12 and t20.

[0043] With this configuration, the position detection unit 114 can detect the medium end surface 201 of the recording medium 11, and accordingly, the position of the recording medium 11 can also be identified.

[0044] It should be noted that the logic levels exemplified here are not limited to this example. For example, in this embodiment, the voltage Vout is set to an L level before the recording medium 11 passes through the light receiving units 111 and 112 and after the recording medium 11 passes through the light receiving units 111 and 112, and the voltage Vout is set to an H level after the recording medium 11 passes through the light receiving unit 112 and before the recording medium passes through the light receiving unit 111, but these may be set to an H level and an L level, respectively.

[0045] (About generating interrupt jobs) Based on the result of identifying the position of the recording medium 11 by the position detection unit 114, the main controller 101 controls the intermittent conveyance of the recording medium 11 by the conveyance rollers 9 and the scanning and recording by the recording head 109. Therefore, a configuration and control are required that can generate a predetermined interrupt job based on the identification result, interrupt the conveyance of the recording medium 11 by the conveyance rollers 9, and start the scanning and recording by the recording head 109.

[0046] Figure 9 is a diagram for explaining a configuration capable of generating an interrupt job in the main controller 101. In this embodiment, the input port 115 includes a rising edge detection unit 115' and a falling edge detection unit 115", each of which receives the voltage Vout. The rising edge detection unit 115' detects the rising edge (change from L level to H level) of the voltage Vout. The falling edge detection unit 115" detects the falling edge (change from H level to L level) of the voltage Vout. Details will be described later, but the rising edge detection unit 115' and the falling edge detection unit 115" each generate detection signals SigR and SigF based on the voltage Vout and provide them to the CPU 702 as an interrupt job.

[0047] Figure 10 is a diagram for explaining the generation mode of an interrupt job, and is an enlarged view based on the waveform 610 of Figure 7(c2). The rising edge detection unit 115' detects that the voltage Vout changing from L level to H level has become greater than the reference voltage Vref, and generates a detection signal SigR accordingly. The falling edge detection unit 115" detects that the voltage Vout changing from H level to L level has become smaller than the reference voltage Vref, and generates a detection signal SigF accordingly. Note that the reference voltage Vref can be set to any voltage value between the L level and the H level as a reference value, and for example, the median value between the L level and the H level is set. The rising edge detection unit 115' and the falling edge detection unit 115" typically use a comparator that compares the magnitude of the reference voltage Vref and the voltage Vout.

[0048] FIG. 11 is a flowchart showing an example of a method for detecting the position of the recording medium 11 according to this embodiment. This flowchart is mainly executed by the CPU 702, and the outline thereof is that an interrupt job is generated based on the detection results of the rising edge detection unit 115′ and the falling edge detection unit 115″, and the position of the recording medium 11 at that time is identified.

[0049] In step S803 (hereinafter simply referred to as "S803," and the same applies to other steps described below), the CPU 702 determines whether or not there is a rising edge in the output voltage Vout of the differential signal output unit 113. This determination is made using the detection signal SigR of the rising edge detection unit 115'. If a rising edge of the voltage Vout is detected, the process proceeds to S805; otherwise, the process returns to S803.

[0050] In S805, in response to receiving the detection signal SigR, the CPU 702 acquires the detection result of the encoder sensor 107b at that time (the rotation amount of the conveying roller 9, ie, the conveying amount of the recording medium 11), and then proceeds to S809.

[0051] In S809, the CPU 702 determines whether or not it has received both the detection signals SigR and SigF. If it has received both the detection signals SigR and SigF, it proceeds to S810, and if not (i.e., it has not received the detection signal SigF), it proceeds to S804.

[0052] In S804, the CPU 702 determines whether or not there is a fall edge in the output voltage Vout of the differential signal output unit 113. This determination is made by the detection signal SigF of the fall edge detection unit 115". If a fall edge in the voltage Vout is detected, proceed to S806; if not, return to S804.

[0053] In S806, in response to receiving the detection signal SigF, the CPU 702 acquires the detection result of the encoder sensor 107b at that time in the same procedure as in S805, and then proceeds to S809.

[0054] In S810, the CPU 702 performs arithmetic processing on the detection results of the encoder sensor 107b acquired in S805 and S806.

[0055] As described above, the detection signal SigR is generated in response to the voltage Vout changing from L level to H level becoming greater than the reference value Vref. In this embodiment, this occurs at time t11 (see FIG. 10), which corresponds to the timing when the recording medium 11 is not located in the detection area 601 of the light receiving unit 111 and a part of the recording medium 11 is located in the detection area 602 of the light receiving unit 112, as can be seen from FIGS. 7(a1) and 7(a2). Similarly, the detection signal SigF is generated in response to the voltage Vout changing from H level to L level becoming smaller than the reference value Vref. In this embodiment, this occurs at time t21 (see FIG. 10), which corresponds to the timing when a part of the recording medium 11 is located in the detection area 601 and the entire recording medium 11 is located in the detection area 602, as can be seen from FIGS. 7(c1) and 7(c2).

[0056] The position of the recording medium 11 can be calculated based on the timing of generation of the detection signals SigR and SigF and the associated detection result of the encoder sensor 107b (the conveyance amount of the recording medium 11). In this embodiment, it is assumed that the medium end surface 201 of the recording medium 11 is detected at time t15, which is the intermediate timing between times t11 and t21, and further, the position of the recording medium 11 can be identified based on the detection result of the encoder sensor 107b.

[0057] In another embodiment, the position of the recording medium 11 may be calculated based on position information that can be associated with times t11 and t21 (or times t10 and t22, or times t12 and t20). For example, the positions of the medium end surface 201 that correspond to times t11 and t21 may be set in advance, and in that case, the position of the recording medium 11 can be identified in response to the calculation of time t15.

[0058] According to this type of control, an interrupt job is generated based on the result of the position detection unit 114 identifying the position of the recording medium 11, thereby interrupting the transport of the recording medium 11 by the transport roller 9 and allowing the recording head 109 to start scanning and recording. Furthermore, by configuring the rising edge and falling edge of the voltage Vout to be individually detectable by the rising edge detection unit 115' and the falling edge detection unit 115", respectively, the circuit operation is not switched during signal processing. Therefore, the generation of the interrupt job can be achieved more quickly and reliably with a relatively simple configuration.

[0059] As described above, according to this embodiment, the position of the recording medium 11 is detected based on the differential signal between the light receiving sections 111 and 112 of the position detection unit 114, and the effects of the state of the recording medium and the environment of the conveyance path are reduced in the calculation processing at that time. Therefore, this embodiment is advantageous in improving the accuracy of detecting the position of the recording medium 11. Furthermore, based on the detected position of the recording medium 11, it is possible to appropriately generate an interrupt job for performing intermittent conveyance of the recording medium 11 by the conveyance roller 9 and scanning and recording by the print head 109.

[0060] (program) The present invention may be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in a computer of the system or device read and execute the program. For example, the present invention may be realized by a circuit (e.g., an ASIC) that realizes one or more functions.

[0061] (others) In the embodiments, individual elements are named based on their main functions, but the functions described in the embodiments may be sub-functions and are not strictly limited to these expressions. Furthermore, these expressions can be replaced with other similar expressions. For the same purpose, the expression "unit" can be replaced with "tool," "component," "member," "structure," "assembly," etc. Alternatively, these terms may be omitted or added. In addition, the ink is not limited to a colored liquid containing a dye or pigment, but may be a colorless, transparent liquid, i.e., the ink is a liquid in a broad sense. From this perspective, the recording device 100 may be referred to as a liquid ejection device, and the recording head 109 may be referred to as a liquid ejection head.

[0062] Furthermore, two or more selectable elements exemplified in the embodiments are not strictly limited to the examples and may be arbitrarily combined, for example, each of the two or more selectable elements may be additionally or alternatively selected. For example, when two elements A and B are arbitrarily combined, they may be expressed as "A and / or B" or "at least one of A and B" to indicate either A only, B only, or both A and B.

[0063] (Summary of the embodiment) [1] A recording apparatus comprising a recording unit for recording on a recording medium, a transport unit for transporting the recording medium, and a position detection unit for detecting the position of the recording medium, The position detection means a light emitting unit that irradiates light onto a transport path of the recording medium; a first light receiving unit that detects reflected light from the transport path; a second light receiving unit that detects reflected light from the transport path, the second light receiving unit being arranged alongside the first light receiving unit in the transport direction of the recording medium; the position of the recording medium is identified based on a differential signal between the signal from the first light receiving unit and the signal from the second light receiving unit. A recording device characterized by: [2] further comprising a control unit for controlling the driving of the recording unit and the conveying unit, The control means Identifying the position of the recording medium based on the differential signal; Based on the result of the determination, the drive control of the recording means and the conveying means is performed. The recording device according to [1]. [3] a value of the differential signal before the recording medium passes through the first light receiving unit and the second light receiving unit and after the recording medium passes through the first light receiving unit and the second light receiving unit is set as a first signal value; a value of the differential signal after the recording medium has passed through the first light receiving unit and before the recording medium has passed through the second light receiving unit is set as a second signal value; a timing at which the differential signal changes from the first signal value to the second signal value is defined as a first time; When the timing at which the differential signal changes from the second signal value to the first signal value is defined as a second time, The control means performs the identification based on the first time and the second time. The recording device according to [2]. [4] The control means interrupts the conveyance of the recording medium by the conveyance means based on the result of the determination, and controls the driving of the recording means. The recording device according to [2] or [3], [5] The differential signal output unit outputs the differential signal. The recording device according to any one of [1] to [4], [6] The differential signal output unit includes a differential amplifier circuit. The recording device according to [5]. [7] Each of the first light receiving section and the second light receiving section is configured by arranging two or more light receiving elements. The recording device according to any one of [1] to [6], characterized in that: [8] The recording means A recording head; a carriage on which the recording head is mounted and which moves back and forth in one direction to cause the recording head to scan; Including, The light emitting unit, the first light receiving unit, and the second light receiving unit are attached to the carriage. The recording device according to any one of [1] to [7], characterized in that: [9] A control method for a recording device including a recording unit that records on a recording medium, a transport unit that transports the recording medium, and a position detection unit that detects the position of the recording medium, comprising: The position detection means a light emitting unit that irradiates light onto a transport path of the recording medium; a first light receiving unit that detects reflected light from the transport path; a second light receiving unit that detects reflected light from the transport path, the second light receiving unit being arranged alongside the first light receiving unit in the transport direction of the recording medium; Including, The control method includes: outputting a differential signal between the signal from the first light receiving unit and the signal from the second light receiving unit; determining the position of the recording medium based on the differential signal; a step of controlling the driving of the recording means based on the result of the identification; Contains A control method comprising:

[10] A program for causing a computer to execute each step of the control method described in [9]. The program can be stored in a computer-readable non-volatile storage medium.

[0064] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0065] 100: recording device, 110: light emitting unit, 111: light receiving unit, 112: light receiving unit, 113: differential signal output unit, 114: position detection unit.

Claims

1. A recording apparatus comprising a recording unit for recording on a recording medium, a transport unit for transporting the recording medium, and a position detection unit for detecting the position of the recording medium, The position detection means a light emitting unit that irradiates light onto a transport path of the recording medium; a first light receiving unit that detects reflected light from the transport path; a second light receiving unit that detects reflected light from the transport path, the second light receiving unit being arranged alongside the first light receiving unit in the transport direction of the recording medium; the position of the recording medium is identified based on a differential signal between the signal from the first light receiving unit and the signal from the second light receiving unit. A recording device characterized by:

2. further comprising a control unit for controlling the driving of the recording unit and the conveying unit, The control means Identifying the position of the recording medium based on the differential signal; Based on the result of the determination, the drive control of the recording means and the conveying means is performed.

2. The recording apparatus according to claim 1.

3. a value of the differential signal before the recording medium passes through the first light receiving unit and the second light receiving unit and a value of the differential signal after the recording medium passes through the first light receiving unit and the second light receiving unit are defined as a first signal value; a value of the differential signal after the recording medium has passed through the first light receiving unit and before the recording medium has passed through the second light receiving unit is set as a second signal value; a timing at which the differential signal changes from the first signal value to the second signal value is defined as a first time; When the timing at which the differential signal changes from the second signal value to the first signal value is defined as a second time, The control means performs the determination based on the first time and the second time.

3. The recording apparatus according to claim 2.

4. The control means interrupts the conveyance of the recording medium by the conveyance means based on the result of the determination, and controls the driving of the recording means.

4. The recording apparatus according to claim 2 or 3.

5. The differential signal output unit outputs the differential signal.

2. The recording apparatus according to claim 1.

6. The differential signal output unit includes a differential amplifier circuit.

6. The recording apparatus according to claim 5.

7. Each of the first light receiving section and the second light receiving section is configured by arranging two or more light receiving elements.

2. The recording apparatus according to claim 1.

8. The recording means A recording head; a carriage on which the recording head is mounted and which moves back and forth in one direction to cause the recording head to scan; Including, The light emitting unit, the first light receiving unit, and the second light receiving unit are attached to the carriage.

2. The recording apparatus according to claim 1.

9. A control method for a recording device including a recording unit that records on a recording medium, a transport unit that transports the recording medium, and a position detection unit that detects the position of the recording medium, comprising: The position detection means a light emitting unit that irradiates light onto a transport path of the recording medium; a first light receiving unit that detects reflected light from the transport path; a second light receiving unit that detects reflected light from the transport path, the second light receiving unit being arranged alongside the first light receiving unit in the transport direction of the recording medium; Including, The control method includes: outputting a differential signal between the signal from the first light receiving unit and the signal from the second light receiving unit; determining the position of the recording medium based on the differential signal; a step of controlling the driving of the recording means based on the result of the identification; Contains A control method comprising:

10. A program for causing a computer to execute each step of the control method according to claim 9.

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