Liquid dispensing device

Abstract

To provide a liquid discharge device that can suppress deterioration in detection accuracy of a sensor.SOLUTION: A liquid discharge device 14 includes: a head 39 including a nozzle 44B for discharging liquid; a sensor 110 for detecting a medium to be discharged 12; a structure 51 to which the head 39 and the sensor 110 are fixed; and a carriage 23 reciprocating in a specific direction relative to the medium to be discharged 12. The structure 51 is detachably fitted to the carriage 23.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a liquid ejection device that ejects liquid from a nozzle of a head onto a discharged medium.

Background Art

[0002] As a liquid ejection device that ejects liquid from a nozzle of a head onto a discharged medium, for example, an inkjet recording device of Patent Document 1 is known. The recording device of Patent Document 1 includes a recording head, a sensor that detects a recording material, and a carriage on which the recording head and the sensor are mounted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the recording device of Patent Document 1, for example, when ink is ejected from the recording head, ink mist generated may adhere to the sensor, resulting in a decrease in the detection accuracy of the sensor. However, in the above recording device, since the sensor cannot be replaced, there is a problem that the device is likely to malfunction due to contamination of the sensor.

[0005] An object of the present invention is to provide a liquid ejection device capable of suppressing a decrease in the detection accuracy of a sensor.

Means for Solving the Problems

[0006] (1) The liquid dispensing device according to the present invention comprises a head having a nozzle for dispensing liquid, a sensor for detecting the medium to be dispensed, a structure to which the head and the sensor are fixed, and a carriage that reciprocates in a predetermined direction relative to the medium to be dispensed. The structure is detachably attached to the carriage.

[0007] According to the present invention, since the structure to which the head and sensor are fixed can be removed from the carriage, the sensor can be replaced. This makes it possible to suppress the decrease in detection accuracy due to sensor contamination. Furthermore, this allows the liquid dispensing device to be used for a longer period of time.

[0008] (2) The above sensor may be a reflective type optical sensor.

[0009] Because reflective optical sensors are small, the carriage and structure can be made smaller. Furthermore, because reflective optical sensors are lightweight, users can easily remove the structure.

[0010] (3) The above-mentioned light sensor may have a light generating unit that generates light corresponding to an input signal, and a light receiving unit that converts the received light into a voltage.

[0011] Because the optical sensor, fixed to the structure, includes both a light generating unit and a light receiving unit, there is no need to place sensor-related components on the carriage. By simply replacing the structure to which the head and sensor are fixed, the decrease in detection accuracy due to sensor contamination can be suppressed. In addition, the liquid dispensing device can be used for a longer period of time.

[0012] (4) The liquid dispensing device may further include an amplifier that amplifies the signal from the sensor and a carriage substrate fixed to the carriage. The amplifier may be located on the carriage substrate.

[0013] The amplifier used to more accurately detect the sensor's output signal is less susceptible to ink mist. Since the amplifier is not fixed to the structure, it does not need to be replaced when the structure is replaced, minimizing the number of parts that need replacing. This allows for lower replacement costs.

[0014] (5) The head may have a piezoelectric element that is driven in response to a discharge signal and discharges liquid from the nozzle. The liquid discharge device may further include a head board that is fixed to the structure and sends a discharge signal to the piezoelectric element. The head board may be electrically connected to a carriage board fixed to the carriage such that the contact state and non-contact state change depending on the attachment and detachment of the structure. The sensor may be electrically connected to the head board.

[0015] If the sensor were electrically connected to the carriage board without going through the head board, the connection structure for the sensor would become complex because the contact state between the head board and the carriage board, and the contact state between the sensor and the carriage board, would change depending on whether the structure is attached or detached. With the above configuration, the sensor is electrically connected to the carriage board via the head board, so the electrical connection structure between the sensor and the carriage board is simplified.

[0016] (6) The head may have a first head equipped with a plurality of nozzles for discharging a first color, and a second head equipped with a plurality of nozzles for discharging a second color. The structure may have a first structure to which the first head is fixed, and a second structure to which the second head is fixed. The first structure and the second structure may be separately and detachably attached to the carriage.

[0017] Since only one of the first or second structure can be removed from the carriage, sensor replacement becomes easier.

[0018] (7) The above sensor may be fixed to only one of the above first structure and the above second structure.

[0019] Only the one of the first structure and the second structure to which the sensor is fixed can be removed from the carriage. Therefore, when the detection accuracy of the sensor decreases, only the structure to which the sensor is fixed needs to be replaced, preventing the unnecessary head from being replaced. Also, for example, when only the head fixed to the structure to which the sensor is not fixed needs to be replaced between the first head and the second head, it is possible to select not to replace the sensor.

[0020] (8) The above first color may be black, and the above second color may be a color.

[0021] For example, when frequently performing monochrome printing, only the first head having nozzles that eject black will be used more often. Therefore, the degrees of wear of the color and black nozzles often vary, and by separating them, unnecessary replacements can be prevented.

[0022] (9) The liquid ejection device may further include a cap that receives the liquid ejected from the above nozzle. The carriage may reciprocate in a first direction approaching the above cap in the above predetermined direction and a second direction away from the above cap. The above sensor may be fixed to the structure arranged in the above second direction among the above first structure and the above second structure.

[0023] When the carriage moves in the direction from the position away from the cap to the capping position where the cap covers the nozzles, the sensor no longer passes through the cap in the predetermined direction, making it less likely to get dirty. Therefore, a decrease in detection accuracy due to dirt on the sensor is suppressed.

[0024] (10) The distance between the above sensor and the ejected medium may be greater than the distance between the above head and the ejected medium.

[0025] Since the sensor is disposed above the nozzle surface of the head, mist generated when discharging liquid from the nozzle to the discharged medium is less likely to contact the sensor. For this reason, the sensor is less likely to get dirty, and thus a decrease in detection accuracy due to dirt on the sensor is suppressed.

[0026] (11) The liquid discharge apparatus according to the present invention includes a head having a nozzle that discharges liquid, a sensor having a light emitting unit that emits light for detecting the discharged medium and a light receiving unit that receives the light emitted from the light emitting unit, a transparent body that covers the light emitting unit and the light receiving unit, a structure to which the head and the transparent body are fixed, and a carriage to which the sensor is fixed and that reciprocates in a predetermined direction with respect to the discharged medium. The structure is detachably attached to the carriage.

[0027] According to the present invention, adhesion of mist generated when liquid is discharged from the nozzle to the sensor is suppressed by the transparent body. Since the structure to which the head and the transparent body are fixed can be removed from the carriage, the transparent body can be replaced. For this reason, a decrease in detection accuracy of the sensor due to dirt on the transparent body can be suppressed.

[0028] (12) The transparent body may be a lens that condenses the light emitted by the light emitting unit.

[0029] It is possible to suppress a decrease in detection accuracy of the sensor due to dirt on the lens while improving the detection accuracy of the sensor.

[0030] (13) The liquid discharge apparatus according to the present invention includes a head having a nozzle that discharges liquid, a sensor having a light emitting unit that emits light for detecting the discharged medium and a light receiving unit that receives the light emitted from the light emitting unit, a mirror that reflects the light emitted by the light emitting unit, a structure to which the head and the mirror are fixed, and a carriage to which the sensor is fixed and that reciprocates in a predetermined direction with respect to the discharged medium. The structure is detachably attached to the carriage.

[0031] According to the present invention, the structure to which the head and mirror are fixed can be removed from the carriage, making it possible to replace the mirror. Therefore, it is possible to suppress the decrease in the detection accuracy of the sensor due to dirt on the mirror. [Effects of the Invention]

[0032] The liquid dispensing device according to the present invention can suppress a decrease in the detection accuracy of the sensor. [Brief explanation of the drawing]

[0033] [Figure 1] Figure 1 is an external perspective view of the multifunction printer 10. [Figure 2] Figure 2 is a schematic longitudinal cross-sectional view showing the internal structure of the printer unit 11. [Figure 3] Figure 3 shows the state in which the first cap 70A and the second cap 70B are positioned to the right of the platen 42. [Figure 4] Figure 4 is a simplified diagram showing the electrical connection between the media sensor 110 and the control unit 130. [Figure 5] Figure 5 is a block diagram showing the configuration of the control unit 130 and the storage unit 140. [Figure 6] Figure 6 shows the state in which the carriage 23 has moved to a position where it faces the first cap 70A and the second cap 70B in the vertical direction 7. [Figure 7] Figure 7 shows the state in which the first cap 70A and the second cap 70B are in contact with the lower surface 43C of the first head 43 and the lower surface 44C of the second head 44. [Figure 8] Figure 8 is a simplified diagram of the recording unit 24 according to a modified example. [Figure 9] Figure 9 is another simplified configuration diagram of the recording unit 24 according to a modified example. [Modes for carrying out the invention]

[0034] Embodiments of the present invention will be described below. It goes without saying that the embodiments described below are merely examples of the present invention, and the embodiments of the present invention can be modified as appropriate without changing the gist of the invention. Furthermore, in the following description, the vertical direction 7 is defined based on the state in which the multifunction printer 10 is installed for use (the state in Figure 1), the front-to-back direction 8 is defined with the surface in which the opening 13 is formed as the front, and the left-to-right direction 9 (an example of the width direction) is defined when viewing the multifunction printer 10 from the front. In this embodiment, when the multifunction printer 10 is installed for use, the vertical direction 7 corresponds to the vertical direction, and the front-to-back direction 8 and left-to-right direction 9 correspond to the horizontal direction. The front-to-back direction 8 and left-to-right direction 9 are orthogonal.

[0035] [Overall configuration of the 10-function printer] As shown in Figure 1, the multifunction device 10 is generally shaped like a rectangular parallelepiped. The multifunction device 10 is equipped with a printer unit 11 (an example of an image recording device) at the bottom that records images onto paper 12 (see Figure 2) using an inkjet recording method. The multifunction device 10 has various functions such as facsimile and printing functions.

[0036] As shown in Figure 2, the printer unit 11 includes a liquid ejection device equipped with a recording unit 24 and a transport device. The transport device includes a feed tray 20, an output tray 21, a feed unit 15, a pair of transport rollers 49, and a pair of output rollers 50.

[0037] [Feed / Delivery Tray 20] As shown in Figure 1, the printer unit 11 has an opening 13 on its front. The feed tray 20 can be inserted and removed from the opening 13 in the front-to-back direction 8. The feed tray 20 can support paper 12 of various sizes.

[0038] The feeding tray 20 is box-shaped with an open top. The feeding tray 20 is equipped with a bottom plate 32. The bottom plate 32 can support multiple standard sizes of paper 12, such as A4, B5, legal size, and postcard size.

[0039] [Discharge Tray 21] As shown in Figure 1, the output tray 21 is located above the feed tray 20. The output tray 21 supports the paper 12 that has been printed with images by the recording unit 24 and then ejected.

[0040] [Feeding section 15] As shown in Figure 2, the feeding unit 15 is positioned above the bottom plate 32 of the feeding tray 20 when it is inserted into the printer unit 11. The feeding unit 15 comprises a feeding roller 25, a feeding arm 26, and a shaft 27.

[0041] The feed roller 25 is rotatably supported at the tip of the feed arm 26. The feed roller 25 rotates when driven by a feed motor 105 (see Figure 5). Alternatively, the feed roller 25 may also rotate when driven by a transport motor 106, which will be described later.

[0042] The base end of the feeding arm 26 is rotatably supported on a shaft 27. The shaft 27 is supported on the frame of the printer unit 11. The feeding arm 26 is biased to rotate toward the bottom plate 32 by its own weight or by an elastic force such as a spring. The feeding roller 25 rotates while in contact with the paper 12 supported on the bottom plate 32, thereby picking up the paper 12 supported on the bottom plate 32 and feeding it to the transport path 65, which will be described later.

[0043] [Transport path 65] As shown in Figure 2, the transport path 65 refers to the space within the printer unit 11 that is partitioned by an outer guide member 18 and an inner guide member 19 that are facing each other at a predetermined interval. The transport path 65 extends rearward from the rear end of the feed tray 20, makes a U-turn while extending upward from below at the rear of the printer unit 11, and is a passage that goes through the recording unit 24 to the output tray 21. The transport path 65 leads to the output tray 21 via the gripping position by the transport roller pair 49, between the recording unit 24 and the platen 42, and the gripping position by the output roller pair 50. The transport direction 16 of the paper 12 within the transport path 65 is indicated by the dashed arrow in Figure 2.

[0044] [Conveyor roller pair 49 and discharge roller pair 50] As shown in Figure 2, the conveyor roller pair 49 is located in the conveyor path 65. The conveyor roller pair 49 comprises a conveyor roller 60 and a pinch roller 61. The discharge roller pair 50 is located downstream of the conveyor roller pair 49 in the conveyor path 65. The discharge roller pair 50 comprises a discharge roller 62 and a spur 63.

[0045] The transport roller 60 and the pinch roller 61 are in contact with each other. The discharge roller 62 and the spur 63 are in contact with each other. The transport roller 60 and the discharge roller 62 rotate when power is transmitted from the transport motor 106 (see Figure 5). As a result, the transport roller pair 49 and the discharge roller pair 50 grip the paper 12 and transport it in the transport direction 16.

[0046] [Platen 42] As shown in Figure 2, the platen 42 is positioned between the transport roller pair 49 and the discharge roller pair 50 in the transport path 65. The platen 42 is positioned opposite the recording unit 24 in the vertical direction 7. The platen 42 supports the paper 12 being transported along the transport path 65 from below.

[0047] [First cap 70A and second cap 70B] As shown in Figure 3, a first cap 70A and a second cap 70B are provided to the right of the platen 42, spaced apart in the left-right direction 9. The first cap 70A is located to the right of the second cap 70B. The left-right distance 9 between the first cap 70A and the second cap 70B corresponds to the left-right distance 9 between the first head 43 and the second head 44, which will be described later.

[0048] The first cap 70A and the second cap 70B are box-shaped members with an open top. The first cap 70A and the second cap 70B are made of an elastic material such as rubber. The first cap 70A and the second cap 70B are supported on the frame 46 via a movable mechanism 71, and can move up and down by the movable mechanism 71, which is driven by a cap drive motor 104 (see Figure 5). The frame 46 is located to the right of the platen 42 and is a plate-shaped member that extends in the front-rear direction 8 and the left-right direction 9. The movable mechanism 71 can be, for example, a mechanism using a ball screw, a link mechanism, or a mechanism using a cam.

[0049] Through holes 72 are provided in the bottom surfaces of the first cap 70A and the second cap 70B, respectively. A tube 73 is connected to each through hole 72. The tube 73 is a flexible resin tube. The tubes 73 extend from each through hole 72, merge together, and then connect to the waste ink tank 78. A switching valve 80 is located at the merging point of the tubes 73. The switching valve 80 is configured to switch between a first path connecting the first cap 70A and the waste ink tank 78, and a second path connecting the second cap 70B and the waste ink tank 78. The switching of the switching valve 80 is controlled by the control unit 130. A suction pump 77 is located between the switching valve 80 and the waste ink tank 78 in the tube 73. The drive of the suction pump 77 is controlled by the control unit 130. This allows the control unit 130 to individually suction the first cap 70A and the second cap 70B using the suction pump 77.

[0050] [Record Section 24] The recording unit 24 will be described with reference to Figures 2 to 4. The recording unit 24 is positioned between the transport roller pair 49 and the discharge roller pair 50 in the transport path 65. The recording unit 24 is positioned above the transport path 65, facing the platen 42. The recording unit 24 comprises a carriage 23, a structure 51, a recording head 39 (an example of a head), and a media sensor 110 (an example of a sensor).

[0051] The carriage 23 is positioned above the transport path 65, facing the platen 42. With the structure 51, recording head 39, and media sensor 110 mounted on it, the carriage 23 reciprocates in the scanning direction (left-right direction 9) perpendicular to the transport direction 16. The carriage 23 is supported by guide rails (not shown) that are spaced apart in the front-rear direction 8 of the platen 42. A known belt mechanism (not shown) is provided on at least one of the guide rails. The carriage 23 is connected to the belt mechanism. The belt mechanism is driven by a carriage drive motor 103 (see Figure 5). This allows the carriage 23 to reciprocate in the left-right direction 9 (an example of a predetermined direction). In other words, the carriage 23 can reciprocate to the right (an example of a first direction) towards the first cap 70A and the second cap 70B, and to the left (an example of a second direction) away from the first cap 70A and the second cap 70B (see Figure 3).

[0052] A carriage board 52 is fixed to the carriage 23. The carriage board 52 has an electrical circuit (not shown) connected to the control unit 130 (see Figure 5), described later, by a first electrical wiring 101. The electrical circuit has a first connection terminal 52A and a second connection terminal 52B that are exposed to the outside from the carriage board 52. An amplifier 53 is located on the carriage board 52. The amplifier 53 is electrically connected to the electrical circuit of the carriage board 52. The amplifier 53 amplifies the signal from the media sensor 110 and outputs it to the control unit 130.

[0053] The structure 51 is detachably attached to the carriage 23. The structure 51 is attached to the carriage 23 by fastening means that can be easily attached and detached by the user, such as hooks. The structure 51 has a first structure 51A and a second structure 51B (see Figure 3). The first structure 51A is located to the right of the second structure 51B (an example of a first direction). In other words, the second structure 51B is located to the left of the first structure 51A (an example of a second direction). The first structure 51A and the second structure 51B are substantially flat plates that extend in the front-to-back direction 8 and the left-to-right direction 9. The first structure 51A and the second structure 51B are detachably attached to the carriage 23 separately.

[0054] A first head board 54 (an example of a head board) is fixed to the first structure 51A (see Figure 4). The first head board 54 has an electrical circuit including a third connection terminal 54A that can be electrically connected to the first connection terminal 52A. The third connection terminal 54A is exposed to the outside of the first structure 51A so as to be in contact with the first connection terminal 52A when the first structure 51A is attached to the carriage 23. The third connection terminal 54A is configured to be in a non-contact state with the first connection terminal 52A when the first structure 51A is removed from the carriage 23.

[0055] The first head board 54 has a first driver IC 56. The first driver IC 56 drives the first piezoelectric element 43A, described later, by applying a voltage to the first piezoelectric element 43A in response to an ejection signal from the control unit 130.

[0056] A second head board 55 (an example of a head board) is fixed to the second structure 51B. The second head board 55 has an electrical circuit including a fourth connection terminal 55A that can be electrically connected to the second connection terminal 52B. The fourth connection terminal 55A is exposed to the outside of the second structure 51B so as to be in contact with the second connection terminal 52B when the second structure 51B is attached to the carriage 23. The fourth connection terminal 55A is configured to be in a non-contact state with the second connection terminal 52B when the second structure 51B is removed from the carriage 23.

[0057] The second head board 55 has a second driver IC 57. The second driver IC 57 drives the second piezoelectric element 44A, described later, by applying a voltage to the second piezoelectric element 44A in response to an output signal from the control unit 130.

[0058] The recording head 39 is fixed to the structure 51. Specifically, the recording head 39 has a first head 43 fixed to the first structure 51A and a second head 44 fixed to the second structure 51B.

[0059] The first head 43 has a plurality of first nozzles 43B for ejecting ink. Each first nozzle 43B is formed on the lower surface 43C of the first head 43. Each first nozzle 43B ejects black ink (an example of a first color). A first piezoelectric element 43A (see Figure 5) is provided inside each first nozzle 43B. The first piezoelectric element 43A is electrically connected to the first driver IC 56 of the first head substrate 54. The first piezoelectric element 43A is an element that deforms when a DC voltage is supplied from the first driver IC 56. By deforming, the first piezoelectric element 43A applies pressure to the ink inside the first nozzle 43B, causing the ink to be ejected from the first nozzle 43B. For example, lead zirconate titanate (PZT) can be used as the first piezoelectric element 43A.

[0060] The second head 44 has a plurality of second nozzles 44B for ejecting ink. Each first nozzle 44B is formed on the lower surface 44C of the second head 44. Each second nozzle 44B ejects color ink (an example of a second color). A second piezoelectric element 44A (see Figure 5) is provided inside each second nozzle 44B. The second piezoelectric element 44A is electrically connected to the second driver IC 57 of the second head substrate 55. The second piezoelectric element 44A is an element that deforms when a DC voltage is supplied from the second driver IC 57. By deforming, the second piezoelectric element 44A applies pressure to the ink inside the second nozzle 44B, causing the ink to be ejected from the second nozzle 44B. For example, lead zirconate titanate (PZT) can be used as the second piezoelectric element 44A.

[0061] The first head 43 and the second head 44 are supplied with ink from an ink cartridge (not shown). The first head 43 and the second head 44 eject ink as tiny ink droplets from the first nozzle 43B and the second nozzle 44B, respectively. As the carriage 23 moves back and forth in the left-right direction 9, ink droplets are ejected from the first nozzle 43B and the second nozzle 44B toward the platen 42. As a result, the ink droplets land on the paper 12 supported by the platen 42, and an image is recorded on the paper 12.

[0062] The media sensor 110 is fixed to the second structure 51B. The media sensor 110 is located upstream of the second head 44 in the transport direction 16. The media sensor 110 is located above the lower surface 44C of the second head 44. The vertical distance L1 between the media sensor 110 and the paper 12 is greater than the vertical distance L2 between the lower surface 44C of the second head 44 and the paper 12. The media sensor 110 detects the paper 12 supported by the platen 42.

[0063] Furthermore, the media sensor 110 is positioned to the left of the second head 44. In other words, when the cap 70B, which will be described later, moves to a position that covers the second head 44, the media sensor 110 is positioned so that it does not need to pass over the cap 70B in the left-right direction 9.

[0064] The media sensor 110 is a reflective light sensor. The media sensor 110 is connected to the second head board 55 by a second electrical wiring 102. Thus, the media sensor 110 is electrically connected to the control unit 130 via the second head board 55 and the carriage board 52. The media sensor 110 includes a light-emitting unit 111 (an example of a light-generating unit) consisting of a light-emitting diode and the like, and a light-receiving unit 112 consisting of an optical sensor and the like. The light-emitting unit 111 irradiates light onto the platen 42 with an amount of light corresponding to an input signal instructed by the control unit 130 (see Figure 5), which will be described later. The light irradiated onto the platen 42 is reflected by the platen 42 or the paper 12 supported by the platen 42. The reflected light is received by the light-receiving unit 112. The light-receiving unit 112 converts the received light into a voltage corresponding to the amount of light received, and outputs an electrical signal corresponding to the amount of light received to the control unit 130. For example, the media sensor 110 outputs an electrical signal with a higher level to the control unit 130 as the amount of light received increases.

[0065] [Control unit 130 and storage unit 140] The configurations of the control unit 130 and the storage unit 140 will be explained below with reference to Figure 5.

[0066] As shown in Figure 5, the control unit 130 includes a CPU 131 and an ASIC 135. The storage unit 140 includes a ROM 132, a RAM 133, and an EEPROM 134. The CPU 131, ASIC 135, ROM 132, RAM 133, and EEPROM 134 are connected by an internal bus 137.

[0067] ROM132 stores programs that the CPU131 uses to control various operations. RAM133 is used as a temporary storage area for data and signals used by the CPU131 when executing the above programs, or as a working area for data processing. EEPROM134 stores settings and flags that should be retained even after the power is turned off.

[0068] The ASIC135 is connected to a feeding motor 105, a transport motor 106, and a carriage drive motor 103. The ASIC135 incorporates drive circuits to control each motor. The CPU 131 outputs drive signals to the corresponding drive circuits (not shown) for each motor to rotate them. The drive circuits output a drive current to the corresponding motor according to the drive signals received from the CPU 131. This causes the corresponding motor to rotate. In other words, the control unit 130 controls the feeding motor 105 to feed the paper 12 to the feeding unit 15. The control unit 130 also controls the transport motor 106 to transport the paper 12 to the transport roller pair 49 and the discharge roller pair 50. The control unit 130 also controls the carriage drive motor 103 to move the carriage 23. The control unit 130 recognizes the amount of reflected light received based on the level of the electrical signal obtained from the media sensor 110. Furthermore, the control unit 130 controls the drive of the pump motor 107 to drive the suction pump 77.

[0069] The control unit 130 outputs an ejection signal to the first driver IC 56 on the first head board 54 via the carriage board 52. The first driver IC drives the first piezoelectric element 43A by applying a voltage to the first piezoelectric element 43A in response to the received ejection signal. When voltage is applied to the first piezoelectric element 43A, it deforms, thereby applying pressure to the ink in the first nozzle 43B and ejecting the ink from the first nozzle 43B.

[0070] The control unit 130 outputs an ejection signal to the second driver IC 57 on the second head board 55 via the carriage board 52. The second driver IC 57 drives the second piezoelectric element 44A by applying a voltage to the second piezoelectric element 44A in response to the received ejection signal. When voltage is applied to the second piezoelectric element 44A, it deforms, thereby applying pressure to the ink in the second nozzle 44B and ejecting the ink from the second nozzle 44B.

[0071] The control unit 130 outputs an input signal to the light-emitting unit 111 of the media sensor 110 via the carriage board 52 and the second head board 55. The light-emitting unit 111 irradiates light toward the platen 42 with an amount of light corresponding to the received input signal. When the light-receiving unit 112 receives reflected light from the platen 42 or the paper 12 that was irradiated from the light-emitting unit 111, it outputs an electrical signal corresponding to the amount of light received to the control unit 130 via the second head board 55 and the carriage board 52. The control unit 130 detects the left and right edge positions of the paper 12 based on the electrical signal from the light-emitting unit 111.

[0072] [Image recording operation] Next, we will explain the operation of the multifunction printer 10 when an image is recorded on paper 12.

[0073] The image recording operation is initiated when a print command to the paper 12 is sent to the control unit 130 from the operation unit 17 of the multifunction printer 10 (see Figure 1) or from an external device connected to the multifunction printer 10.

[0074] When a print command is sent to the control unit 130, the control unit 130 drives the feed motor 105. This causes the feed roller 25 to rotate, and the paper 12 supported in the feed tray 20 is fed into the transport path 65.

[0075] When the paper 12 reaches the position where the transport roller pair 49 is positioned, the control unit 130 drives the transport motor 106. This causes the transport roller 60 and the discharge roller 62 to rotate, and the paper 12 is transported by the transport roller pair 49 in the transport direction 16 to a position where the paper 12 can face the media sensor 110.

[0076] Next, the control unit 130 drives the carriage drive motor 103 to move the carriage 23 to the paper detection start position. The paper detection start position is located outward (to the right or left) of the paper 12 supported by the platen 42 in the left-right direction 9. In this embodiment, the paper detection start position is located to the right of the paper 12 supported by the platen 42.

[0077] The control unit 130 drives the carriage drive motor 103 to move the carriage 23 from the paper detection start position to a position to the left of the paper 12. In parallel with the movement of the carriage 23, the control unit 130 outputs an electrical signal of a predetermined level to the media sensor 110. As a result, the light-emitting part 111 of the media sensor 110 irradiates the paper 12 below with light of an amount corresponding to the predetermined level. Then, an electrical signal corresponding to the amount of reflected light received from the paper 12 is output from the light-receiving part 112 to the control unit 130. At this time, the electrical signal is amplified by the amplifier 53. The control unit 130 detects the left and right edge positions of the paper 12 based on the difference between the position of the moved carriage 23 and the received electrical signals from the platen 42 and the paper 12.

[0078] When the left and right edges of the paper 12 are detected, the carriage 23 moves to a position opposite the paper 12 in the vertical direction 7. Then, black ink is ejected from multiple first nozzles 43B of the first head 43, and color ink is ejected from multiple second nozzles 44B of the second head 44. As a result, an image is recorded on the paper 12. At this time, even if ink mist is generated by the ejection of ink from the first nozzles 43B and the second nozzles 44B, the media sensor 110 is positioned above the lower surface 44C of the second head 44, so the ink mist is unlikely to come into contact with the media sensor 110.

[0079] When an image is recorded on the paper 12, the control unit 130 rotates the transport roller 60 and the discharge roller 62. As a result, the paper 12 is gripped by the discharge roller 62 and the spur 63 of the transport roller pair 49 and transported in the transport direction 16. The paper 12 that has been transported in the transport direction 16 by the transport roller pair 49 is discharged into the discharge tray 21.

[0080] [Movement of the first cap 70A and the second cap 70B] Before starting maintenance to clean the first nozzle 43B and the second nozzle 44B, the control unit 130 moves the carriage 23 to the right from a position where the first head 43 and the second head 44 face the platen 42 in the vertical direction 7 (see Figure 3) to a separated position where the first head 43 and the second head 44 face the first cap 70A and the second cap 70B in the vertical direction 7 (see Figure 6). Then, the control unit 130 moves the first cap 70A and the second cap 70B upward from the separated position to the covering position shown in Figure 7. In the covering position, the upper end of the first cap 70A and the second cap 70B are in contact with the lower surface 43C of the first head 43, and the upper end of the second cap 70B is in contact with the lower surface 44C of the second head 44. In other words, the first cap 70A and the second cap 70B cover the multiple first nozzles 43B and the multiple second nozzles 44B from below, respectively. The control unit 130 starts maintenance when the first cap 70A and the second cap 70B are in the covering position.

[0081] When performing maintenance on the first head 43, the control unit 130 switches the path of the tube 73 to the first path and drives the suction pump 77. This generates negative pressure inside the first cap 70A, and when this negative pressure reaches a predetermined pressure, ink is discharged from the multiple first nozzles 43B into the cap 70A. At this time, any foreign matter that was clogging the first nozzles 43B is also discharged. The first cap 70A receives the ink and foreign matter. The ink and foreign matter received by the first cap 70A are sucked into the tube 73 and discharged through the tube 73 to the waste ink tank 78 (see Figure 3).

[0082] When performing maintenance on the second head 44, the control unit 130 switches the path of the tube 73 to the second path and drives the suction pump 77. This generates negative pressure inside the second cap 70B, and when this negative pressure reaches a predetermined pressure, ink is discharged from the multiple second nozzles 44B into the cap 70B. At this time, any foreign matter that was clogging the second nozzles 44B is also discharged. The second cap 70B receives the ink and foreign matter. The ink and foreign matter received by the second cap 70B are sucked into the tube 73 and discharged through the tube 73 to the waste ink tank 78 (see Figure 3).

[0083] [Effects of the Embodiment] In the multifunction printer 10, the structure 51 to which the recording head 39 and media sensor 110 are fixed can be removed from the carriage 23, making it possible to replace the media sensor 110. This suppresses the decrease in detection accuracy due to dirt on the media sensor 110. In addition, this allows the multifunction printer 10 to be used for a longer period of time.

[0084] In the multifunction printer 10, the media sensor 110 is a reflective optical sensor, and therefore is small. This allows the carriage 23 and the structure 51 to be made smaller. Also, because the reflective optical sensor is lightweight, the user can easily remove the structure 51.

[0085] In the multifunction printer 10, the media sensor 110 fixed to the structure 51 includes a light-emitting section 111 and a light-receiving section 112. Therefore, there is no need to place components related to the media sensor 110 on the carriage 23. By simply replacing the structure 51 to which the recording head 39 and the media sensor 110 are fixed, the decrease in detection accuracy due to dirt on the media sensor 110 can be suppressed. In addition, the multifunction printer 10 can be used for a longer period of time.

[0086] In the multifunction printer 10, the amplifier 53, used to more accurately detect the output signal of the media sensor 110, is less susceptible to ink mist. Since the amplifier 53 is not fixed to the structure 51, it does not need to be replaced when the structure 51 is replaced, minimizing the number of parts that need to be replaced. This makes it possible to reduce the cost of replacements.

[0087] If the media sensor 110 were electrically connected to the carriage board 52 without going through the second head board 55, the connection structure of the media sensor 110 would become complex because the contact state between the second head board 55 and the carriage board 52, and the contact state between the media sensor 110 and the carriage board 52 would change depending on whether the second structure 51B is attached or detached. In the multifunction printer 10, the media sensor 110 is electrically connected to the carriage board 52 via the second head board 55, so the electrical connection structure between the media sensor 110 and the carriage board 52 is simple.

[0088] In the multifunction printer 10, the first structure 51A and the second structure 51B are separately and detachably attached to the carriage 23, so that only one of the first structure 51A or the second structure 51B can be removed from the carriage 23. This makes it easy to replace the media sensor 110.

[0089] In the multifunction printer 10, if the detection accuracy of the media sensor 110 deteriorates, only the second structure 51B to which the media sensor 110 is fixed needs to be removed from the carriage 23, thus avoiding the need to replace the first head 43, which does not require replacement. On the other hand, if only the first head 43 fixed to the first structure 51A needs to be replaced, the option of not replacing the media sensor 110 is available.

[0090] In the multifunction printer 10, the ink ejected from the first nozzle 43B of the first head 43 is black ink, and the ink ejected from the second nozzle 44B of the second head 44 is color ink. Therefore, for example, when monochrome printing is performed frequently, only the first head 43 will be used more, so the wear rate of the first nozzle 43B will be greater than that of the second nozzle 44B. In this case, by replacing only the first structure 51A to which the first head 43 is fixed, it is possible to prevent the unnecessary replacement of the second head 44.

[0091] In the multifunction printer 10, the media sensor 110 is fixed to the left of the second structure 51B. Therefore, when the carriage 23 moves to the right from a position to the left of the first cap 70A and the second cap 70B toward the capping position where the first cap and the second cap 70B cover the first nozzle 43B and the second nozzle 44B, the media sensor 110 does not pass the first cap 70A and the second cap 70B toward the right, and is therefore less likely to become soiled. As a result, a decrease in detection accuracy due to soiling of the media sensor 110 is suppressed.

[0092] In the multifunction printer 10, the vertical distance L1 between the media sensor 110 and the paper 12 (platen 42) is greater than the vertical distance L2 between the lower surface 44C of the second head 44 and the paper 12 (platen 42). Therefore, mist generated when ink is ejected downward from the first nozzle 43B and the second nozzle 44B is less likely to come into contact with the media sensor 110. As a result, contamination of the media sensor 110 is suppressed, and the decrease in detection accuracy due to contamination of the media sensor 110 is suppressed.

[0093] [Differentiation] In the multifunction printer 10, the media sensor 110 is fixed to the second structure 51B, but as shown in Figure 8, it may also be fixed to the carriage 23. In this case, the media sensor 110 is connected to the carriage substrate 52 by the second electrical wiring 102. A lens 121 (an example of a transparent body) that focuses the light emitted by the light-emitting unit 111 is fixed to the second structure 51B. In this way, the media sensor 110 is covered from below by the lens 121, so that the ink mist generated when ink is ejected downward from the second nozzle 44B does not come into contact with the media sensor 110. Therefore, the detection accuracy of the media sensor 110 can be improved by the lens 121, while suppressing a decrease in the detection accuracy of the media sensor 110 due to dirt on the lens 121.

[0094] In the multifunction printer 10, the media sensor 110 is fixed to the second structure 51B, but as shown in Figure 9, it may also be fixed to the carriage 23. In this case, the media sensor 110 is connected to the carriage substrate 52 by the second electrical wiring 102. A mirror 122 that reflects the light emitted by the light-emitting unit 111 is fixed to the second structure 51B. The mirror 122 reflects the reflected light downward toward the platen 42. The mirror 122 also reflects the light reflected by the platen 42 or the paper 12 toward the light-receiving unit 112. In this way, the second structure 51B to which the mirror 122 is fixed can be removed from the carriage 23, making it possible to replace the mirror 122. This makes it possible to suppress a decrease in the detection accuracy of the media sensor 110 due to dirt on the mirror 122.

[0095] In the multifunction printer 10, the first structure 51A and the second structure 51B were separately detachably attached to the carriage 23, but they may also be detachably attached to the carriage 23 as a single unit.

[0096] In the multifunction printer 10, the structure 51 was attached to the carriage 23 by fastening means that can be easily attached and detached by the user, such as hooks. However, the fastening means is not particularly limited as long as it is detachably attached to the carriage 23. For example, the structure 51 may be attached to the carriage 23 by bolts, or it may be attached to the carriage 23 by press-fitting a part of the structure 51 into the carriage 23.

[0097] In the multifunction printer 10, the recording head 39 has a first head 43 and a second head 44, but it may also have a third head. In this case, in addition to the first cap 70A and the second cap 70B, a third cap that can contact the third head may be provided.

[0098] In the multifunction printer 10, the media sensor 110 was a reflective light sensor, but it may also be a transmissive light sensor. In this case, one of the light-emitting unit 111 and the light-receiving unit 112 may be fixed to the second structure 51B. The media sensor 110 may also be an ultrasonic sensor or an electrostatic sensor.

[0099] In the multifunction printer 10, the media sensor 110 is fixed to the second structure 51B, but it may also be fixed to the first structure 51A. [Explanation of symbols]

[0100] 14...Liquid discharge device 23.. Carriage 39... Recording head 43...1st Head 43A...First piezoelectric element 43B...First Nozzle 44...2nd Head 44A...Second piezoelectric element 44B...Second nozzle 51...Structure 51A...1st structure 51B...Second structure 52...Carriage board 53... Amplifier 55... Head board 70A...1st cap 70B...Second cap 110...Media Sensor 111...Light-emitting part 112... Light receiving section 121...Lens 122...Mirror

Claims

1. A head having a nozzle for dispensing liquid, A sensor that detects the medium being dispensed, A structure to which the above head and the above sensor are fixed, It comprises a carriage that reciprocates in a predetermined direction relative to the medium to be discharged, The above structure is detachably attached to the above carriage. An amplifier that amplifies the signal from the above sensor, The carriage further comprises a carriage substrate fixed to the above carriage, The above amplifier is a liquid dispensing device located on the carriage substrate.

2. The head described above has a piezoelectric element that is driven in response to a discharge signal and discharges liquid from the nozzle, The structure further comprises a head board fixed to the above structure and sending an ejection signal to the piezoelectric element, The head board is electrically connected to the carriage board, which is fixed to the carriage, such that the contact state and non-contact state change depending on the attachment and detachment of the structure. The liquid dispensing device according to claim 1, wherein the above sensor is electrically connected to the above head board.

3. A head having a nozzle for discharging liquid, A sensor that detects the medium being dispensed, A structure to which the above head and the above sensor are fixed, It comprises a carriage that reciprocates in a predetermined direction relative to the medium to be discharged, The above structure is detachably attached to the above carriage. The head described above has a piezoelectric element that is driven in response to a discharge signal and discharges liquid from the nozzle, The structure further comprises a head board fixed to the above structure and sending an ejection signal to the piezoelectric element, The head board is electrically connected to the carriage board, which is fixed to the carriage, such that the contact state and non-contact state change depending on the attachment and detachment of the structure. The above sensor is a liquid dispensing device electrically connected to the above head board.

4. The liquid dispensing device according to any one of claims 1 to 3, wherein the distance between the sensor and the dispensing medium is greater than the distance between the head and the dispensing medium.

5. A head having a nozzle for discharging liquid, A sensor that detects the medium being dispensed, A structure to which the above head and the above sensor are fixed, It comprises a carriage that reciprocates in a predetermined direction relative to the medium to be discharged, The above structure is detachably attached to the above carriage. A liquid dispensing device in which the distance between the sensor and the dispensing medium is greater than the distance between the head and the dispensing medium.

6. The above head comprises a first head having a plurality of nozzles for discharging a first color, and a second head having a plurality of nozzles for discharging a second color. The above structure comprises a first structure to which the first head is fixed, and a second structure to which the second head is fixed. The liquid dispensing device according to any one of claims 1 to 5, wherein the first structure and the second structure are separately and detachably attached to the carriage.

7. A head having a nozzle for discharging liquid, A sensor that detects the medium being dispensed, A structure to which the above head and the above sensor are fixed, It comprises a carriage that reciprocates in a predetermined direction relative to the medium to be discharged, The above structure is detachably attached to the above carriage. The above head comprises a first head having a plurality of nozzles for discharging a first color, and a second head having a plurality of nozzles for discharging a second color. The above structure comprises a first structure to which the first head is fixed, and a second structure to which the second head is fixed. The first structure and the second structure described above are liquid dispensing devices that are separately and detachably attached to the carriage.

8. The liquid dispensing device according to claim 6 or 7, wherein the sensor is fixed to only one of the first structure and the second structure.

9. The liquid dispensing device according to any one of claims 6 to 8, wherein the first color is black and the second color is color.

10. The system further includes a cap for receiving the liquid discharged from the nozzle mentioned above. The carriage moves back and forth in a first direction approaching the cap, which is the predetermined direction, and in a second direction away from the cap. The liquid dispensing device according to any one of claims 6 to 9, wherein the sensor is fixed to the first structure and the second structure which is arranged in the second direction.

11. The liquid dispensing device according to any one of claims 1 to 10, wherein the sensor is a reflective type optical sensor.

12. The liquid dispensing device according to claim 11, wherein the light sensor comprises a light generating unit that generates light corresponding to an input signal and a light receiving unit that converts the received light into a voltage.

13. A head having a nozzle for dispensing liquid, A sensor having a light-emitting unit that emits light to detect the medium to be dispensed and a light-receiving unit that receives the light emitted from the light-emitting unit, A transparent body covering the above-mentioned light-emitting part and the above-mentioned light-receiving part, A structure to which the above head and the above transparent body are fixed, The above sensor is fixed to a carriage that reciprocates in a predetermined direction relative to the medium to be dispensed, The above structure is a liquid dispensing device that is detachably attached to the carriage.

14. The liquid dispensing device according to claim 13, wherein the transparent body is a lens that collects the light emitted by the light-emitting part.

15. A head having a nozzle for dispensing liquid, A sensor having a light-emitting unit that emits light to detect the medium to be dispensed and a light-receiving unit that receives the light emitted from the light-emitting unit, The above-mentioned light-emitting part includes a mirror that reflects the light emitted, A structure to which the above head and the above mirror are fixed, The above sensor is fixed to a carriage that reciprocates in a predetermined direction relative to the medium to be dispensed, The above structure is a liquid dispensing device that is detachably attached to the carriage.

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