Media holding member and printing apparatus

Abstract

To provide a media holding member and a printing apparatus that suppress the occurrence of false detections. [Solution] The media holding member 100 includes a media holding portion 113 that holds the end of the media M in the direction intersecting the transport direction with the support surface 50a, with respect to the media M being transported in the transport direction along the support surface 50a of the media support portion 50, by sandwiching it with the support surface 50a, and a main body portion 101 that supports the media holding portion 113 and is engageable with the media support portion 50. The media holding portion 113 or the main body portion 101 has light-transmitting portions 114a, 114b, and the irradiated light for detecting an object to be detected on the support surface 50a, which is irradiated from an optical sensor 70 that is scanned in the direction intersecting, passes through the light-transmitting portions 114a, 114b.

Description

Technical Field

[0001] The present invention relates to a media pressing member and a printing apparatus.

Background Art

[0002] Conventionally, a media pressing member for holding roll paper or the like on a platen has been known. For such a member, various devices have been made to facilitate the detection of the position by an optical sensor or the like. For example, Patent Document 1 discloses a printing apparatus provided with a media clamp having a recognition pattern.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] [[ID=�4]] However, the media clamp described in Patent Document 1 has a problem that it is difficult to correctly detect the recognition pattern. Specifically, dust derived from the installation environment of the printing apparatus or ink mist generated from the print head may adhere to the recognition pattern. The contamination of the recognition pattern makes optical detection difficult and may induce false detection. That is, a media pressing member that suppresses the occurrence of false detection has been demanded.

Means for Solving the Problems

[0005] The media holding member comprises a media holding portion that holds the end of the media in an intersecting direction intersecting the conveying direction with the support surface of the media support portion as the media is conveyed in the conveying direction along the support surface of the media support portion, and a main body portion that supports the media holding portion and is engageable with the media support portion, wherein the media holding portion or the main body portion has a light-transmitting portion, and the irradiated light for detecting an object to be detected on the support surface, which is irradiated from an optical sensor scanned in the intersecting direction, passes through the light-transmitting portion.

[0006] The printing apparatus comprises a media support section that supports a medium being transported in the transport direction on a support surface; a head that discharges liquid onto the medium supported on the support surface; a head carriage that moves the head in a direction intersecting the transport direction; an optical sensor mounted on the head carriage and scanned in the intersecting direction to detect an object to be detected on the support surface; a media holding section that presses the end of the medium in the intersecting direction between itself and the support surface; and a media holding member comprising a main body that supports the media holding section and is engageable with the media support section, wherein the media holding section or the main body has a light-transmitting section that allows light from the optical sensor to pass through. [Brief explanation of the drawing]

[0007] [Figure 1] A schematic diagram showing the configuration of a printing apparatus according to the first embodiment. [Figure 2] A perspective view showing the arrangement of media holding members and optical sensors. [Figure 3] A side view showing the arrangement of the media holding member and optical sensor, etc. [Figure 4] A perspective view showing the configuration of the media holding member. [Figure 5] A perspective view showing the configuration of the media holding member. [Figure 6] A schematic diagram showing another form of the light-transmitting section. [Figure 7] An enlarged plan view showing the detailed arrangement and dimensions of the light-transmitting section. [Figure 8] A schematic diagram of the output signal of an optical sensor. [Figure 9] A perspective view showing the configuration of the media holding member according to the second embodiment. [Figure 10] A side view showing the configuration of the media holding member. [Figure 11] A schematic diagram of the output signal of the optical sensor related to the comparative example. [Modes for carrying out the invention]

[0008] In the embodiments described below, a media-holding member and a printing apparatus 1 equipped with the media-holding member will be illustrated with reference to the drawings. The printing apparatus 1 is a large-format printer that prints on continuous form sheets. The media-holding member of the present invention is not limited to being provided in a printing apparatus, and the printing apparatus of the present invention is not limited to the following configuration.

[0009] In the following diagrams, the X, Y, and Z axes are shown as mutually orthogonal coordinate axes, with the direction indicated by each arrow being the + direction and the opposite direction being the - direction. When the printing device 1 is placed on a horizontal plane, the -Z direction is the vertical direction. In the following explanation, the +Z direction may also be referred to as upward, and the -Z direction as downward. In the following diagrams, the sizes of the components are different from those in reality for illustrative purposes.

[0010] 1. First Embodiment As shown in Figure 1, the printing apparatus 1 according to this embodiment comprises a structural member 10, a feeding unit 20, a media sliding member 30, a media support unit 50, a transport roller pair 40, a printing unit 60, a blower unit 80, and a media transport unit 90. Although not shown, the printing apparatus 1 also comprises a control unit and a housing.

[0011] In Figure 1, for illustrative purposes, the housing containing the printing unit 60 and other components is omitted. In the following description of Figure 1, unless otherwise specified, the view from the -X direction is described.

[0012] The printing apparatus 1 produces a printed matter by attaching ink to a medium M which is a continuous sheet-like ticket. In the printing apparatus 1, the medium M is fed out from a roll body R1 which is a web, becomes a printed matter, and the printed matter is wound up to become a roll body R2.

[0013] The control unit is electrically connected to each component of the printing apparatus 1 and integrally controls the operation of each component. The control unit includes hardware such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The control unit controls the printing apparatus 1 by executing a predetermined control program by the CPU. The ROM is a non-volatile storage device and stores the control program executed by the CPU and the data processed by the control program. The RAM constitutes the work area of the CPU. The CPU expands the control program read from the ROM or the like into the RAM, and executes the expanded control program to control the printing apparatus 1.

[0014] The conveyance path is defined as the movement path of the medium M from when it is fed out from the roll body R1 until it is wound up as the roll body R2. In FIG. 1, the conveyance path is indicated by a dashed line. In the conveyance path, the web side of the medium M is also referred to as the upstream, and the side where the medium M and the printed matter advance is also referred to as the downstream. In the conveyance path, in the order from upstream to downstream, a feeding unit 20, a medium sliding member 30, a pair of conveyance rollers 40, a medium support unit 50, a printing unit 60, a medium conveyance unit 90, and a blower unit 80 are arranged in the above order. In the conveyance path, the direction in which the medium M travels from upstream to downstream is also referred to as the conveyance direction, and the direction intersecting the conveyance direction is also referred to as the intersecting direction.

[0015] The structural member 10 is a frame that supports each of the above components of the printing apparatus 1. The structural member 10 is formed by assembling a plurality of sheet metal members, tubular members, and the like. In the structural member 10, casters, installation members, or the like may be arranged at a portion that contacts the lower floor.

[0016] The feeding section 20 includes a roll body holding section 21. The feeding section 20 is arranged in the -Y direction below the printing apparatus 1. The roll body holding section 21 supports the roll body R1 so as to be rotatable about an axis along the X-axis. The medium M is pulled by the pair of conveying rollers 40, fed downstream from the roll body R1, and supplied. The roll body R1 is detachable from the printing apparatus 1. The medium M is conveyed substantially upward from the roll body holding section 21 by the pair of conveying rollers 40 and proceeds to the medium sliding member 30.

[0017] The medium M is appropriately selected according to the type of ink to be attached to the medium M, the use of the printed matter, etc. In the printing apparatus 1, for example, so-called soft solvent ink is applied as the ink. In this case, a sheet made of polyvinyl chloride or the like is used as the medium M.

[0018] The medium sliding member 30 has a substantially arc-shaped curved surface and supports the conveyed medium M. The conveying direction of the medium M is changed from substantially upward to substantially the +Y direction by the above-mentioned curved surface of the medium sliding member 30. The medium M is conveyed while sliding in contact with the above-mentioned curved surface of the medium sliding member 30. The medium M proceeds from the medium sliding member 30 to the pair of conveying rollers 40.

[0019] Although not shown, the medium sliding member 30 incorporates a heating heater for heating the medium M. The heating heater pre-heats the medium M before the ink is attached. Thereby, the fixing property and solubility of the ink with respect to the medium M are improved.

[0020] The pair of conveying rollers 40 includes conveying rollers 41 and 42. The conveying rollers 41 and 42 form a pair and their sides are in contact with each other. The conveying roller 41 is arranged below the conveying path, and the conveying roller 4 is arranged above the conveying path. The conveying rollers 41 and each rotate about an axis along the X-axis.

[0021] The conveyor roller 41 is driven by a drive motor (not shown) and rotates. The conveyor roller 42 is a driven roller and rotates in the opposite direction to the conveyor roller 41 as the conveyor roller 41 rotates. When the conveyor roller 41 rotates counterclockwise, the conveyor roller 42 rotates clockwise. As a result, the medium M is trapped between the conveyor rollers 41 and 42 and conveyed downstream. The medium M then proceeds to the medium support section 50.

[0022] The media support section 50 includes a support surface (not shown). The media support section 50 is a component that constitutes a so-called platen. The length of the media support section 50 along the X-axis is longer than the length of the media M along the X-axis. The support surface is the surface of the media support section 50 that faces upward and aligns with the XY plane. The media support section 50 supports the media M as it is being transported in the transport direction with its support surface. The media M is transported along the support surface of the media support section 50 in the transport direction, which is the +Y direction. In the media support section 50, the surface of the media M that faces upward becomes the printing surface.

[0023] The printing apparatus 1 includes a media holding member 100. The media holding member 100 holds both ends of the media M in the direction along the X-axis, which is the intersecting direction. Two media holding members 100 are arranged in the media support section 50, corresponding to the +X direction end and the -X direction end of the media M. The media M is held in place by the media holding members 100 in the media support section 50 and transported in the +Y direction, which is the transport direction in the media support section 50. Details of the media holding member 100 will be described later.

[0024] Although not shown in the diagram, the media support section 50 incorporates an electric heater for heating the media M. The electric heater heats the media M when the ink is applied. This improves the adhesion and solubility of the ink to the media M, and also makes it easier for volatile components such as solvents contained in the ink to evaporate.

[0025] The printing unit 60 prints on the medium M. The printing unit 60 includes a head 61, a head carriage 62, and an optical sensor (not shown). The printing unit 60 is positioned above the medium support unit 50.

[0026] The head carriage 62 is supported above the structural member 10 so as to be able to reciprocate along the X-axis. The movement of the head carriage 62 is driven by a motor for the head carriage (not shown). The head carriage 62 supports the head 61 above the media support section 50 and reciprocates in a direction along the X-axis, which is the intersecting direction. The optical sensor is located on the head carriage 62. Details of the optical sensor will be described later.

[0027] The print head 61 ejects liquid ink onto the printing surface of the media M, which is supported on the support surface of the media support unit 50. The print head 61, together with the print carriage 62, reciprocates along the X-axis within a range that includes the area facing the media support unit 50 in the vertical direction.

[0028] Although not shown in the diagram, a nozzle surface is located on the downward-facing surface of the head 61. Multiple nozzle rows are provided on the nozzle surface. Each nozzle row consists of multiple nozzles that eject ink. Each nozzle row is supplied with ink of various colors, such as black, cyan, yellow, and magenta, individually from an ink container (not shown). Each color of ink is ejected from each nozzle row toward the printing surface of the medium M.

[0029] The ink applied to the printing device 1 is a soft solvent ink, as described above. A soft solvent ink is, for example, a solvent ink that does not contain intentionally added water and contains glycol ether-based solvents or lactone-based solvents as the main solvent. The liquid ejected by the head 61 may also include a processing solution and a clear ink that does not contain colorants.

[0030] In the media support unit 50, the media M is transported in the +Y direction while the head 61 is moved back and forth along the X axis together with the head carriage 62. At this time, ink is applied to the printing surface of the media M at any desired timing, thereby printing images such as pictures, photographs, text, and patterns onto the media M. The printed media M then proceeds to the downstream media transport unit 90 and blower unit 80.

[0031] The media transport unit 90 includes a media sliding unit 91, a heating unit 92, a tension bar 93, an arm unit 95, a rotating unit 97, and a winding unit 99.

[0032] Each component of the media transport unit 90 is supported by the structural member 10 and is arranged in the +Y direction of the printing device 1. In the media transport unit 90, the media sliding unit 91, tension bar 93, and winding unit 99 are arranged in the above order in the direction of transport.

[0033] The media sliding section 91 has a curved surface that supports the media M, and supports the media M being conveyed. The curved surface of the media sliding section 91 faces approximately upward on the media sliding section 91. The media M is conveyed by sliding in contact with the curved surface of the media sliding section 91. In the direction along the X axis, the length of the curved surface of the media sliding section 91 is longer than the length of the media M. The conveying direction of the media M is changed by the curved surface of the media sliding section 91 from the +Y direction to the +Y direction and slightly downward.

[0034] The media sliding portion 91 has a pair of side walls 91p. The side walls 91p are positioned at the +X end and the -X end of the media sliding portion 91, respectively. Each side wall 91p is a substantially plate-shaped member, formed, for example, from sheet metal. Each side wall 91p includes a surface that aligns with the YZ plane and intersects with the curved surface of the media sliding portion 91.

[0035] The media sliding section 91 has a heating section 92. The heating section 92 is an electric heater that heats the media M. The heating section 92 is positioned inside the curved surface of the media sliding section 91. The heating section 92 promotes the volatilization of volatile components contained in the ink adhering to the media M. This prevents ink components from adhering to other parts when the media M is wound onto the roll body R2 in the winding section 99.

[0036] The air blower 80 blows air onto the printed surface of the medium M to assist in the volatilization of the volatile components. The air blower 80 is supported by the structural member 10 above the transport path of the medium sliding part 91. The air blower 80 blows air over the entire area along the X-axis of the medium M.

[0037] Heating by the heating unit 92 and air blowing by the air blowing unit 80 accelerate the drying of the ink adhering to the medium M. This makes it possible to wind the medium M in the downstream winding unit 99. The medium M is pulled by the winding unit 99 and transported to the tension bar 93.

[0038] The tension bar 93 applies tension to the medium M between the medium sliding portion 91 and the winding portion 99. The tension bar 93 is a substantially cylindrical member, with its longitudinal direction aligned with the X-axis. The -X end and the +X end of the tension bar 93 are each supported by arm portions 95. Supported by a pair of arm portions 95, the tension bar 93 protrudes slightly downward in the +Y direction from the medium sliding portion 91.

[0039] In the printing apparatus 1, the tension bar 93 protrudes downward and slightly in the +Y direction from the media sliding section 91, so the media M is conveyed while being pushed approximately in the +Y direction by the tension bar 93. As a result, the media M is wound onto the winding section 99 while tension is applied.

[0040] The surface corresponding to the cylindrical side of the tension bar 93 is formed to be relatively smooth with low frictional resistance. Therefore, the medium M slides along the side of the tension bar 93 even while tension is applied. The cylindrical side of the tension bar 93 may be covered with a sheet-like material that contacts the medium M. Note that the tension bar 93 does not rotate relative to the arm portion 95.

[0041] Each arm portion 95 is a roughly rod-shaped member. When the tension bar 93 is functioning, each arm portion 95 supports the tension bar 93 at one end in the roughly +Y direction. The other end of each arm portion 95 in the roughly -Y direction is rotatably supported by the pivot portion 97.

[0042] In a plan view from above, the length of each arm section 95, which is the distance between one end and the other end, is shorter than the length of the media sliding section 91 along the conveying direction. As a result, the arm sections 95 and other components are relatively small, allowing the media conveying section 90 to be further miniaturized.

[0043] The rotating parts 97 are arranged in accordance with each arm part 95. More specifically, the rotating parts 97 are provided on the side wall 91p in the +X direction and the side wall 91p in the -X direction of the media sliding part 91. The pair of rotating parts 97 rotate clockwise and counterclockwise around the vicinity of the other end of each arm part 95 as the center of rotation, driven by a drive unit (not shown).

[0044] Therefore, one end of each arm 95 rotates clockwise and counterclockwise while supporting the tension bar 93. This changes the position of the tension bar 93, particularly its protrusion distance in the +Y direction, and adjusts the strength of the tension applied to the medium M. Specifically, when the tension bar 93 rotates clockwise, its protrusion distance from the medium sliding part 91 in the +Y direction increases, pushing the medium M in the +Y direction and applying strong tension. Conversely, when the tension bar 93 rotates counterclockwise, its protrusion distance from the medium sliding part 91 in the +Y direction decreases, weakening the force pushing the medium M in the +Y direction and reducing the applied tension.

[0045] Each rotating part 97 is positioned closer to the downstream end (+Y direction) of the media sliding part 91 than to the upstream end (-Y direction) of the media sliding part 91, with respect to the media M transport direction. As a result, the length of the arm part 95 is shortened compared to when each rotating part 97 is positioned closer to the upstream end of the media sliding part 91. Therefore, it becomes easier to further miniaturize the media transport part 90, and the weight and cost of the device are further reduced.

[0046] The tension bar 93 changes the transport direction of the medium M from downward in the +Y direction to downward in the -Y direction. The medium M proceeds to the winding section 99 via the tension bar 93.

[0047] The winding unit 99 winds the medium M onto a roll body R2. The winding unit 99 includes a roll body holding unit 99a. The winding unit 99 is positioned in the +Y direction below the printing device 1. The roll body holding unit 99a rotates counterclockwise by the rotational drive of a drive motor (not shown) to wind the medium M into a roll body R2. At this time, the roll body R2 rotates around an axis along the X axis.

[0048] When winding the medium M onto the roll body R2, the tension applied by the tension bar 93 improves the winding accuracy. As a result, misalignment of both ends of the medium M along the X-axis is reduced, resulting in a roll body R2 with relatively aligned ends. In addition, the applied tension reduces the gaps between the stacked medium Ms, resulting in a dense roll body R2. There is an appropriate range for the strength of the tension applied to the medium M. The tension is set appropriately according to the type and dimensions of the medium M.

[0049] As a result, the printed medium M becomes a roll R2. The roll R2 can be removed from the printing device 1 in approximately the +Y direction. The printed material from the printing device 1 is used for signage and other applications.

[0050] As shown in Figure 2, an optical sensor 70 is mounted on the +X side of the head carriage 62. The optical sensor 70 is also supported by the head carriage 62 and moves back and forth along the X axis. The nozzle surface of the optical sensor 70 and the head 61 face the support surface 50a of the media support section 50 in the vertical direction. Note that some components of the printing apparatus 1 are not shown in Figure 2.

[0051] The optical sensor 70 scans in a direction along the X-axis, which is the intersecting direction, to detect an object to be detected on the support surface 50a. The object to be detected here refers to a medium M (not shown) and a medium holding member 100 supported on the support surface 50a. The optical sensor 70 is, for example, a reflective sensor and has a light-emitting part and a light-receiving part, which will be described later. The reflective sensor emits light from the light-emitting part in the -Z direction. If an object to be detected is present on the support surface 50a, the light-receiving part receives the reflected light that travels in the +Z direction, which is generated by the reflection of the light. The reflective sensor detects the presence or absence of an object to be detected from the change in the intensity of the reflected light and outputs the detection result to the control unit. A commercially available product may be used as the reflective sensor.

[0052] The optical sensor 70 detects the presence or absence of an object while moving back and forth along the X-axis. The control unit then identifies the printable area of ​​the medium M in the direction along the X-axis. This allows for adjustment of the printable area of ​​the medium M in the direction along the X-axis.

[0053] As described above, the media holding member 100 holds both ends of the media M in the direction along the X-axis. Therefore, the media holding member 100 is installed near the +X end and the -X end within the scanning range of the head carriage 62. Figure 2 shows the media holding member 100 on the -X end side of the two media holding members 100. The media holding member 100 has a configuration and shape that is substantially symmetrical with respect to a straight line along the Y-axis, so that it can be used without distinction on both sides in the direction along the X-axis.

[0054] As preparation for printing, the user of the printing device 1 places the media holding member 100 on top of the +X and -X sides of the media M. This positions the media M along the X-axis, suppressing meandering and misalignment of the media M. It also prevents the X-axis end of the media M from lifting up, thus preventing contact between the media M and the head 61. Therefore, it is preferable that the length in the Y-axis direction over which the media holding member 100 holds the media M is greater than or equal to the length in the Y-axis direction of the head 61.

[0055] As shown in Figure 3, the media holding member 100 comprises a main body portion 101, a first engaging portion 106, a second engaging portion 109, and a media holding portion (not shown). The first engaging portion 106 and the second engaging portion 109 are formed on the main body portion 101. The media holding portion is provided so as to extend from the main body portion 101 in the +X and -X directions. In other words, the media holding member 100 is composed of the main body portion 101 and the media holding portion, etc. The main body portion 101 or the media holding portion has a light-passing portion, which will be described later, that allows the light irradiated by the optical sensor 70 to pass through. When viewed from the +X direction, the light-emitting portion 71 and the light-receiving portion and the light-passing portion are arranged opposite each other in the vertical direction. In the following description of Figure 3, unless otherwise specified, the view from the +X direction will be described.

[0056] The optical sensor 70 has a light-emitting unit 71 and a light-receiving unit 72. The light-emitting unit 71 emits light in the -Z direction, and the light-receiving unit 72 receives light incident from the -Z direction. During the reciprocating movement of the optical sensor 70 along the X-axis, when the light-emitting unit 71 is positioned opposite the light-passing unit in the vertical direction, the light emitted by the light-emitting unit 71 passes through the light-passing unit and travels in the -Z direction. Conversely, when the light-emitting unit 71 is positioned opposite the area of ​​the medium-holding member 100 other than the light-passing unit, and the medium M in the vertical direction, the light emitted by the light-emitting unit 71 is reflected by the area other than the light-passing unit and the medium M, becoming reflected light that travels towards the optical sensor 70. The reflected light travels in the +Z direction and is received by the light-receiving unit 72. Hereinafter, in the following description, the state in which there is no object to be detected in the -Z direction of the light-emitting unit 71 includes the case in which the light-passing region is located in the -Z direction of the light-emitting unit 71. The light-passing region is the region in which the light emitted from the optical sensor 70, which is irradiated in the -Z direction, passes through the support surface 50a in the -Z direction.

[0057] The media support section 50 has a support surface 50a and a recess 51. The recess 51 is positioned to overlap the light-emitting section 71 and the light-receiving section 72 in the vertical direction. The light emitted from the optical sensor 70 passes through the recess 51 in the -Z direction more easily than through the support surface 50a. In other words, the area where the recess 51 is formed becomes a light-passing region.

[0058] The recess 51 extends along the X-axis. In the direction along the X-axis, the length of the recess 51 is longer than the length of the medium M and approximately equal to the length of the support surface 50a. In other words, the recess 51 is a groove along the direction of the X-axis, which is the intersecting direction. As the head carriage 62 moves back and forth along the X-axis, the light-emitting part 71 and the light-receiving part 72 of the optical sensor 70 are scanned along the recess 51.

[0059] The groove, or recess 51, described above is recessed in the -Z direction relative to the support surface 50a and is composed of a surface 51a. Surface 51a has a downward angle when viewed from the +Y direction. The portion of surface 51a that is illuminated by the light extends in a direction intersecting the -Z direction, which is the direction of illumination of the light. Surface 51a faces the light-emitting unit 71 and the light-receiving unit 72 in the vertical direction, but does not reflect the light emitted from the light-emitting unit 71 to the light-receiving unit 72. In other words, the reflected light from surface 51a relative to the light emitted from the light-emitting unit 71 does not enter the light-receiving unit 72. In this invention, reflected light refers to specular reflection and does not include diffuse reflection. Therefore, even if diffuse reflection reaches the light-receiving unit 72, it is preferable that the amount of light is below a level that the optical sensor 70 does not detect.

[0060] Here, the support surface 50a is not limited to having a recess 51. For example, instead of a recess 51, the area of ​​the support surface 50a where the recess 51 is located may be treated to make it difficult to reflect the irradiated light. Since the reflected light does not enter the light receiving unit 72, just as when the irradiated light passes through the support surface 50a in the -Z direction, the area of ​​the support surface 50a that is treated to make it difficult to reflect the irradiated light will also be treated as a light-passing area. In other words, an area in which the irradiated light emitted from the light-emitting unit 71 is not reflected to the light receiving unit 72 can be called a light-passing area.

[0061] When there is no object to be detected in the -Z direction of the light-emitting unit 71, the light emitted from the light-emitting unit 71 passes through the media holding member 100 and the support surface 50a in the -Z direction. The emitted light is then reflected by the surface 51a of the recess 51 and proceeds to a location other than the light-receiving unit 72. At this time, the light-receiving unit 72 either does not detect the reflected light or the intensity of the reflected light decreases. Therefore, it is determined that there is no object to be detected on the support surface 50a. Because the recess 51 does not reflect the emitted light to the light-receiving unit 72, the optical sensor 70 can detect the object to be detected with high sensitivity.

[0062] The first engaging portion 106 and the second engaging portion 109 are provided protruding in the -Z direction and engage with the media support portion 50. In other words, the main body portion 101 can engage with the media support portion 50. The first engaging portion 106 is located at the -Y direction end of the media holding member 100. The second engaging portion 109 is located near the +Y direction end of the media holding member 100. The media holding member 100 is restricted from moving along the Y axis relative to the media support portion 50, but its movement along the X axis is not restricted. The first engaging portion 106 and the second engaging portion 109 suppress the positioning of the media holding member 100 along the Y axis and prevent it from lifting away from the support surface 50a.

[0063] As shown in Figures 4 and 5, the media holder member 100 comprises a main body 101, a guide hole 103, a release part 105, and a media holding part 113. The main body 101 has a first metal sheet 111 and a second metal sheet 112, and a resin operating part 101a attached to the first metal sheet 111 and the second metal sheet 112. The main body 101 supports the media holding part 113.

[0064] The first sheet metal 111 and the second sheet metal 112 are substantially rectangular when viewed from the +Z direction, with their longitudinal direction aligned with the Y axis. The first sheet metal 111 and the second sheet metal 112 are metal plates having a metallic luster and reflect the light emitted from the light-emitting part 71. The first sheet metal 111 and the second sheet metal 112 are made of a metal such as stainless steel or aluminum.

[0065] The first sheet metal 111 and the second sheet metal 112 overlap in the direction along the Z-axis, with the second sheet metal 112 superimposed on the first sheet metal 111 in the -Z direction. Because the first sheet metal 111 and the second sheet metal 112 are superimposed, the mechanical strength of the media holding member 100 is improved.

[0066] -Viewed from the Z direction, the second sheet metal 112 is smaller than the first sheet metal 111. More specifically, in the direction along the Y axis, the length of the first sheet metal 111 and the length of the second sheet metal 112 are approximately equal. In the direction along the X axis, which is the intersecting direction, the width of the second sheet metal 112 is shorter than the width of the first sheet metal 111.

[0067] Viewed from the -Z direction, there are regions near the -X direction edge and the +X direction edge of the first sheet metal 111 that do not overlap with the second sheet metal 112. These regions are the media holding portions 113. In other words, the media holding member 100 has one media holding portion 113 on each side in the direction along the X axis. Viewed from the -Z direction, the media holding portion 113 is an elongated trapezoid in the direction along the Y axis. The media holding portion 113 in the -X direction and the media holding portion 113 in the +X direction are symmetrical with respect to a straight line along the Y axis.

[0068] Furthermore, the width of the first sheet metal 111 and the width of the second sheet metal 112 in the direction along the X-axis do not need to be in the same relationship as described above throughout the entire area along the Y-axis. Specifically, it is sufficient that the above relationship holds true at least in the area opposite to the scanning range of the head 61 in the vertical direction. In addition, outside of the above-mentioned opposing area, there may be places in the direction along the X-axis where the width of the second sheet metal 112 is longer than the width of the first sheet metal 111.

[0069] The media holding portion 113 is formed from the first sheet metal 111. The media holding portion 113 holds the end of the media M in the direction along the X axis by pressing it against the media M and the support surface 50a. Specifically, in the media holding portion 113, since the second sheet metal 112 is not overlapped with the first sheet metal 111, the gap between the support surface 50a and the media holding portion 113 is wider than the gap where the first sheet metal 111 and the second sheet metal 112 overlap, by the thickness of the second sheet metal 112. The media M is sandwiched in this gap and held down by the support surface 50a and the media holding portion 113. In other words, the main body portion 101 is composed of the overlapping portion of the first sheet metal 111 and the second sheet metal 112, and the media holding portion 113 is composed of the first sheet metal 111 that protrudes from the main body portion 101 without overlapping with the second sheet metal 112. The media holding section 113 may be composed of parts different from those that make up the main body section 101.

[0070] The second sheet metal 112 guides the end face of the medium M in the direction along the X-axis. Specifically, when the medium holding portion 113 holds the medium M, the edge of the second sheet metal 112 in the direction along the X-axis comes into contact with the edge of the end of the medium M in the direction along the X-axis, thereby preventing a part of the medium M from entering an area other than the medium holding portion 113, that is, an area where the first sheet metal 111 and the second sheet metal 112 overlap. This makes it easy and reliable to position the medium holding member 100 relative to the medium M in the direction along the X-axis. Note that when the medium holding portion 113 holds the medium M, the aforementioned edge of the medium M and the aforementioned edge of the second sheet metal 112 do not necessarily have to come into contact.

[0071] As described above, the media holding member 100 is installed at both ends of the media M supported on the support surface 50a in the direction along the X axis. Therefore, the media holding member 100 installed in the -X direction of the support surface 50a holds the media M with the media holding portion 113 on the +X direction side. The media holding member 100 installed in the +X direction of the support surface 50a holds the media M with the media holding portion 113 on the -X direction side.

[0072] The media holding member 100 restricts the movement of the media M along the X-axis, but does not restrict its movement along the Y-axis. The media M can be transported in the direction along the Y-axis while being held down by the media holding member 100.

[0073] The main body 101 has light-transmitting sections 114a and 114b. The light-transmitting sections 114a and 114b are arranged in a region that can face the light-emitting section 71 and the light-receiving section 72 in the vertical direction along the Y-axis. The light-transmitting sections 114a and 114b are arranged in a region where the first sheet metal 111 and the second sheet metal 112 are superimposed along the X-axis. This arrangement suppresses a decrease in strength compared to the case where the light-transmitting sections 114a and 114b are arranged in a region where the first sheet metal 111 and the second sheet metal 112 are not superimposed.

[0074] The arrangement of the light-transmitting portions 114a and 114b in the direction along the X-axis is not limited to the above. The light-transmitting portions 114a and 114b may be arranged in the medium-holding portion 113, or they may be arranged across the region where the medium-holding portion 113 and the first sheet metal 111 and the second sheet metal 112 are superimposed. However, if part or all of the light-transmitting portions 114a and 114b are arranged in the medium-holding portion 113, the medium M must be held so as not to overlap with the light-transmitting portions 114a and 114b.

[0075] The light-transmitting sections 114a and 114b are openings that penetrate the first sheet metal 111 and the second sheet metal 112, and are rectangular when viewed from the +Z direction. The light-transmitting sections 114a and 114b are positioned to overlap with the recess 51 in the vertical direction. In other words, the light-transmitting sections 114a and 114b are positioned to overlap with the light-transmitting region in the vertical direction, and allow the illumination light irradiated from the light-emitting section 71 to pass through the light-transmitting region, so that the reflected light is not reflected to the light-receiving section 72. Multiple light-transmitting sections 114a and 114b, which are openings, are provided along the direction of the X-axis, which is the intersecting direction. Irradiated light from the optical sensor 70, which is scanned in the direction of the X-axis, which is the intersecting direction, for detecting the object to be detected on the support surface 50a, passes through the light-transmitting sections 114a and 114b and proceeds in the -Z direction. This makes it easier to recognize the location where the media holding member 100 is positioned compared to a configuration with a single opening, and allows for accurate detection of the position of the media holding portion 113. The configuration and number of light-transmitting portions 114a and 114b are not limited to those described above.

[0076] Here, as shown in Figure 6, light-transmitting portions 116a and 116b may be used instead of light-transmitting portions 114a and 114b. The light-transmitting portions 116a and 116b may be openings formed by bending a part of the first sheet metal 111 or the second sheet metal 112. Specifically, the light-transmitting portions 116a and 116b are rectangular openings similar to the light-transmitting portions 114a and 114b when viewed from the +Z direction, but they are not through holes like the light-transmitting portions 114a and 114b. The light-transmitting portions 116a and 116b are formed by bending one side of the first sheet metal 111 or the second sheet metal 112 along the X axis in the -Z direction. When viewed from the -X direction, the light emitted from the light-emitting portion 71 passes through the light-transmitting portions 116a and 116b, is reflected by the bent part of the first sheet metal 111 or the second sheet metal 112, and proceeds to a location other than the light-receiving portion 72. The light-transmitting sections 116a and 116b eliminate the need for through-holes, thus reducing the effort required for processing.

[0077] Returning to Figures 4 and 5, each media holding section 113 has a reference section 115. The reference section 115 is a notch provided in the first sheet metal 111. The reference section 115 serves as the starting point when the light-emitting section 71 and light-receiving section 72 are scanned along the X-axis to detect the media holding section 113. One reference section 115 is formed in the first sheet metal 111 that constitutes the media holding section 113, one on the edge at the +X direction end and one on the edge at the -X direction end.

[0078] More specifically, the reference section 115 is provided in the media holding section 113 at a location corresponding to the scanning range of the light-emitting section 71 and light-receiving section 72 of the optical sensor 70. In other words, the two reference sections 115 and the light-transmitting sections 114a and 114b are in overlapping positions in the direction along the X-axis, which is the intersecting direction.

[0079] Since the reference portion 115 serves as the starting point for detecting the media holding portion 113, by accurately forming the reference portion 115 in the media holding portion 113, the position of the media holding portion 113 in the direction along the X axis can be accurately determined. In other words, in the media holding portion 113, areas other than the reference portion 115, such as areas outside the scanning range of the light-emitting portion 71 and the light-receiving portion 72, the precision of processing and molding can be made relatively low, thereby reducing the manufacturing cost of the media holding member 100.

[0080] The operating section 101a is located at the +Y end of the main body 101. The operating section 101a is substantially rectangular parallelepiped in shape. The operating section 101a has two release sections 105.

[0081] The main body 101 can engage with the media support 50 by a first engaging portion 106 and two second engaging portions 109. The first engaging portion 106 engages with the media support 50, but its movement along the X-axis is not restricted. The two second engaging portions 109 engage with the media support 50, and their movement along the X-axis is restricted.

[0082] The two release parts 105 release the engagement of the two second engagement parts 109 with the media support part 50. Specifically, the release parts 105 are positioned on the side of the operating part 101a facing the +X direction and the side facing the -X direction, respectively. Each release part 105 is connected to a second engagement part 109 that protrudes from the second sheet metal 112 in the -Z direction. By grasping the two release parts 105 by hand and pushing them against the aforementioned side, the two second engagement parts 109 are displaced, and the engagement between the two second engagement parts 109 and the media support part 50 is released. With the engagement released, the media holding member 100 can be moved in the +X direction or the -X direction relative to the support surface 50a of the media support part 50. This allows adjustment of the position in which the media M is held by the media holding member 100 along the X axis.

[0083] The first sheet metal 111 has four guide holes 103 and a bent portion 108. The four guide holes 103 are triangular through holes. The guide holes 103 serve as a guide for positioning the end of the medium M relative to the medium holding portion 113 when the end of the medium M is sandwiched between the medium holding portion 113 and the support surface 50a. Two of the four guide holes 103 are located in the medium holding portion 113 in the +X direction, and the other two are located in the medium holding portion 113 in the -X direction. The two pairs of guide holes 103 are each provided facing each other in the direction along the Y axis.

[0084] The bent portion 108 has a shape in which the end of the first sheet metal 111 in the -Y direction is bent in the +Z direction, widening the gap with the support surface 50a. The bent portion 108 makes it easier for the medium M to enter the gap between the medium holding portion 113 and the support surface 50a when the leading end of the medium M in the transport direction is sandwiched in the gap between the medium holding portion 113 and the support surface 50a.

[0085] As shown in Figure 7, the light-transmitting sections 114a and 114b have shapes that are symmetrical with respect to the center line CA along the X-axis of the first sheet metal 111, and are arranged symmetrically. In the following description of Figure 7, unless otherwise specified, the view from the +Z direction will be described. Note that the following forms and arrangements of the light-transmitting sections 114a and 114b are examples only and are not limited thereto.

[0086] The width of the light-transmitting apertures 114a and 114b in the direction along the X-axis is larger than the spot diameter of the irradiated light at the detection position of the optical sensor 70. This ensures sufficient detection accuracy even when considering the movement speed of the optical sensor 70 and the machining accuracy of the light-transmitting apertures 114a and 114b.

[0087] Specifically, the light-transmitting sections 114a and 114b are square, with two opposing sides aligned with the X-axis and the other two opposing sides aligned with the Y-axis. In the light-transmitting sections 114a and 114b, the length L1 of each side is 5.0 mm. In this embodiment, the spot diameter of the light emitted from the light-emitting section 71 relative to the first sheet metal 111 is 3.0 mm. The center of the circle of light emitted onto the first sheet metal 111 can coincide with the intersection of the diagonals of the respective light-transmitting sections 114a and 114b.

[0088] The center line CA and the light-transmitting sections 114a and 114b are separated by a length L3. The length L3 is 5.9 mm, and the light-transmitting sections 114a and 114b are separated by 11.8 mm. As a result, the optical sensor 70 can sufficiently detect the light-transmitting sections 114a and 114b in relation to the sampling period of the optical sensor 70 and the movement speed of the head carriage 62.

[0089] In the direction along the Y-axis, the light-transmitting sections 114a and 114b are each spaced L4 apart from the -Y end of the reference section 115. The length L4 is 4.5 mm.

[0090] Here, as a comparative example, the detection state of the optical sensor 70 with respect to a conventional media holding member 300 will be described. The conventional media holding member 300 has a shape substantially similar to that of the media holding member 100, but does not have light-transmitting parts 114a and 114b, and does not have metallic luster. A metal part that does not have metallic luster is, for example, a painted metal part.

[0091] As shown in Figure 11, when the medium M is held down by the medium holding member 300 and the optical sensor 70 detects the object to be detected relative to the scan line SL, an output signal Od3 is obtained. Although not shown in the figure, the recess 51 described above is provided on the support surface 50a at a position corresponding to the scan line SL. Note that with the optical sensor 70, the greater the intensity of the reflected light received by the light receiving unit 72, the lower the signal output to the control unit, and the smaller the intensity of the reflected light, the higher the signal output to the control unit.

[0092] The output signal Od3 is lower in the medium M and higher in the medium holding member 300 and the support surface 50a. This is because the medium M strongly reflects the light emitted from the light-emitting unit 71, while the recess 51 of the support surface 50a and the medium holding member 300 either do not reflect the light or reflect it weakly.

[0093] The output signal Od3 has only one change point, raising concerns about false detections and detection errors. While placing the recognition pattern on the scan line SL of the media holder 300 allows for obtaining multiple change points, ink mist and dust may adhere to the pattern, making it difficult to read. Furthermore, depending on the type of ink, it may degrade the coating on the recognition pattern or media holder 300, potentially inducing false detections by the optical sensor 70.

[0094] In contrast, as shown in Figure 8, the media holding member 100 of this embodiment provides an output signal Od1. The output signal Od1 is low in areas other than the media M and the light-transmitting portions 114a and 114b of the media holding member 100, and high in the light-transmitting portions 114a and 114b and the support surface 50a.

[0095] This is because the irradiated light is less likely to be reflected toward the light-receiving section 72 in the light-transmitting sections 114a and 114b, while the reflectivity is higher in the media-holding member 100. Specifically, the first sheet metal 111 of the media-holding member 100 has a metallic luster and therefore has a high reflectivity. On the other hand, the recess 51 is less likely to generate reflected light toward the light-receiving section 72, regardless of the color or presence of paint on the support surface 50a. Therefore, the difference in reflectivity between the media-holding member 100 and the support surface 50a is stably increased, suppressing the occurrence of false detections. In addition, since the metallic luster of the first sheet metal 111 is derived from the material, it is less prone to deterioration such as paint peeling, contributing to a reduction in painting costs.

[0096] Since there are two light-transmitting sections 114a and 114b, there are five points where the output signal Od1 changes. This allows, for example, the threshold to be set midway between the high and low output values, and the presence or absence of the media holding member 100 to be determined from the number of times the threshold is exceeded. Furthermore, the printable area of ​​the media M can be easily identified from the positions of the light-transmitting sections 114a and 114b.

[0097] Here, Figures 8 and 11 describe the case where the optical sensor 70 is scanned from the +X end of the support surface 50a in the -X direction. This identifies the boundary of the printable area on the +X side of the medium M. When identifying the boundary of the printable area on the -X side of the medium M, the optical sensor 70 is scanned from the -X end of the support surface 50a in the +X direction. Specifically, for example, the optical sensor 70 is moved from the -X end of the support surface 50a in the +X direction, and then the optical sensor 70 is moved back in the -X direction at the +X end of the support surface 50a. Although not particularly limited, the optical sensor 70 may be moved back and forth as described above to detect both boundaries of the printable area.

[0098] According to this embodiment, the following effects can be obtained.

[0099] This makes it possible to suppress the occurrence of false detections in the optical sensor 70. Specifically, within the scanning range of the optical sensor 70, the optical sensor 70 detects the presence of areas other than the medium M, which is the object to be detected, and the light-transmitting portions 114a and 114b of the medium holding member 100. In other words, when an object to be detected is present in the scanning range, the optical sensor 70 receives reflected light from the object that reflects the irradiated light. In contrast, since there is no object to be detected on the support surface 50a in the light-transmitting portions 114a and 114b, the optical sensor 70 has difficulty receiving reflected light from the object to be detected, and the intensity of the reflected light changes. In other words, the optical sensor 70 identifies the presence and location of the object to be detected from the change in the intensity of the reflected light. Therefore, it is less susceptible to the effects of dirt compared to conventional configurations that detect a recognition pattern. Thus, it is possible to provide a medium holding member 100 and a printing apparatus 1 that suppress the occurrence of false detections in the optical sensor 70.

[0100] 2. Second Embodiment In this embodiment, a media retaining member 200 is provided as an example instead of the media retaining member 100 in the above embodiment. In the media retaining member 200, the shape of the light-transmitting portions 114a and 114b is changed compared to the media retaining member 100 in the above embodiment. Components similar to those in the media retaining member 100 are given the same reference numerals, and redundant explanations are omitted.

[0101] As shown in Figures 9 and 10, the media holder member 200 comprises a main body portion 201, a guide hole 103, an engagement release portion 105, and a media holding portion 213. The main body portion 201 has a third sheet metal 211 and a fourth sheet metal 212 made of metal, and an operating portion 101a attached to the third sheet metal 211 and the fourth sheet metal 212. The main body portion 201 supports the media holding portion 213. The media holding portion 213 or the main body portion 201 has a light-transmitting portion 214. In this embodiment, the light-transmitting portion 214 is included in the main body portion 201.

[0102] The third sheet metal 211 and the fourth sheet metal 212 have an elongated shape in the direction along the Y axis when viewed from the +Z direction. The third sheet metal 211 and the fourth sheet metal 212 are metal plates with a metallic luster and reflect the light emitted from the light-emitting part 71. The third sheet metal 211 and the fourth sheet metal 212 are made of a metal such as stainless steel or aluminum.

[0103] The third sheet metal 211 and the fourth sheet metal 212 overlap in the direction along the Z-axis, with the fourth sheet metal 212 superimposed on the third sheet metal 211 in the -Z direction. Because the third sheet metal 211 and the fourth sheet metal 212 are superimposed, the mechanical strength of the media holding member 200 is improved.

[0104] Viewed from the +Z direction, the fourth sheet metal 212 is smaller than the third sheet metal 211. More specifically, in the direction along the Y axis, the length of the third sheet metal 211 and the length of the fourth sheet metal 212 are approximately equal. In the direction along the X axis, which is the intersecting direction, the width of the fourth sheet metal 212 is shorter than the width of the third sheet metal 211.

[0105] Therefore, when viewed from the -Z direction, there are regions near the -X direction edge and the +X direction edge of the third sheet metal 211 that do not overlap with the fourth sheet metal 212. These regions are the media holding portions 213. In other words, the media holding member 200 has media holding portions 213 on both sides in the direction along the X axis. The media holding portion 213 in the -X direction and the media holding portion 213 in the +X direction are symmetrical with respect to a straight line along the Y axis.

[0106] The media holding portion 213 is not provided on either side of the light passing portion 214, which will be described later, in the direction along the X axis. In other words, with the media holding member 200, the light emitted from the optical sensor 70 does not irradiate the media holding portion 213, and the object to be detected is only the media M.

[0107] Furthermore, the width of the third sheet metal 211 and the width of the fourth sheet metal 212 in the direction along the X-axis do not need to be in the same relationship as described above throughout the entire area along the Y-axis. Specifically, it is sufficient that the above relationship holds true at least in the area opposite to the scanning range of the head 61 in the vertical direction. In addition, outside of the above-mentioned opposing area, there may be places where the width of the fourth sheet metal 212 in the direction along the X-axis is longer than the width of the third sheet metal 211.

[0108] The media holding portion 213 is formed from the third sheet metal 211. The media holding portion 213 holds the end of the media M in the direction along the X axis by pressing it against the media M and the support surface 50a. Specifically, in the media holding portion 213, since the fourth sheet metal 212 is not overlapped with the third sheet metal 211, the gap between the support surface 50a and the media holding portion 213 is wider than the gap where the third sheet metal 211 and the fourth sheet metal 212 overlap, by the thickness of the fourth sheet metal 212. The media M is sandwiched in this gap and held down by the support surface 50a and the media holding portion 213. In other words, the media M is held by being sandwiched between the third sheet metal 211 and the support surface 50a. Therefore, it is possible to securely hold the media M with a relatively simple configuration.

[0109] The fourth sheet metal 212 guides the end face of the medium M in the direction along the X-axis. Specifically, when the medium holding portion 213 holds the medium M, the edge of the fourth sheet metal 212 in the direction along the X-axis comes into contact with the edge of the end of the medium M in the direction along the X-axis, thereby preventing a part of the medium M from entering an area other than the medium holding portion 213, i.e., the area where the third sheet metal 211 and the fourth sheet metal 212 overlap. This makes it easy and reliable to position the medium holding member 200 relative to the medium M in the direction along the X-axis. Note that when the medium holding portion 213 holds the medium M, the aforementioned edge of the medium M and the aforementioned edge of the fourth sheet metal 212 do not necessarily have to come into contact.

[0110] The media holding member 200 is installed near both ends of the support surface 50a in the direction along the X axis. Therefore, in the case of the media holding member 200 installed in the -X direction of the support surface 50a, the media M is held in place by the media holding portion 213 on the +X direction side.

[0111] The media holding member 200 restricts the movement of the media M along the X-axis, but does not restrict its movement along the Y-axis. In other words, the media M can be transported in the direction along the Y-axis while being held down by the media holding member 200.

[0112] The light-transmitting portion 214 is provided in the third sheet metal 211 at a position facing the light-emitting portion 71 and the light-receiving portion 72 in the vertical direction. The light-transmitting portion 214 is made of sheet metal and is bent to conform to the shape of the support surface 50a (not shown) so as to avoid the light emitted from the optical sensor 70. Specifically, when viewed from the +X direction, the light-transmitting portion 214 is bent to conform to the shape of the recess 51 described above. As a result, in the light-transmitting portion 214, the light emitted from the optical sensor 70 passes through the support surface 50a in the -Z direction, and the emitted light is not reflected to the light-receiving portion 72.

[0113] In the light-transmitting portion 214, the dimension in the direction along the Z-axis is formed to be thicker than that of the fourth sheet metal 212 and the third sheet metal 211 in areas other than the light-transmitting portion 214. This ensures that the light-transmitting portion 214 has the mechanical strength to connect the fourth sheet metal 212 and the third sheet metal 211 in areas other than the light-transmitting portion 214 in the -Y and +Y directions. Note that the light-transmitting portion 214 is not limited to being formed as part of the third sheet metal 211, but may also be formed as part of the fourth sheet metal 212, or may be a separate component from the third sheet metal 211 and the fourth sheet metal 212.

[0114] In the media holding member 200, the fourth sheet metal 212 may be omitted. In this case, the ends of the third sheet metal 211 in the +X and -X directions are bent in the +Z direction away from the support surface 50a. That is, the third sheet metal 211 is formed so that the media M can be sandwiched between the media holding portion 213 and the support surface 50a. As a result, even if the fourth sheet metal 212 is omitted, it becomes easier to sandwich the media M between the support surface 50a and the media holding portion 213, and the setting of the media holding member 200 with respect to the media M becomes simpler.

[0115] Reference sections 215 are provided in the +X and -X directions of the light-transmitting section 214. The reference section 215 is shorter in length along the X axis than the reference section 115 in the above embodiment in order to avoid interference with the medium M when pressing down on the medium M.

[0116] According to this embodiment, the same effects as those of the above embodiment can be obtained. [Explanation of Symbols]

[0117] 1...Printing device, 50...Media support part, 50a...Support surface, 51...Recess, 51a...Surface, 61...Head, 62...Head carriage, 70...Optical sensor, 100, 200...Media holding member, 101, 201...Main body, 111...First sheet metal, 112...Second sheet metal, 113, 213...Media holding part, 114a, 114b, 116a, 116b, 214...Light passing part, 115, 215...Reference part, 211...Third sheet metal, 212...Fourth sheet metal, M...Media.

Claims

1. A media holding part holds the end of a medium in an intersecting direction that intersects the conveying direction with the support surface of the media support part, so as to be conveyed in the conveying direction along the support surface of the media support part. It comprises a main body that supports the media holding portion and is engageable with the media support portion, The media holding portion or the main body portion has a light-transmitting portion, A media holding member characterized in that the light emitted from an optical sensor scanned in the aforementioned cross direction for detecting an object to be detected on the support surface passes through the light-transmitting portion.

2. The media holding portion is formed from a first sheet metal, The main body comprises the first sheet metal and the second sheet metal which is superimposed on the first sheet metal. The media holding member according to claim 1, wherein the light-transmitting portion is an opening that penetrates the first sheet metal and the second sheet metal.

3. In the aforementioned intersecting direction, the width of the second sheet metal is shorter than the width of the first sheet metal. The medium holding member according to claim 2, wherein the second sheet metal guides the end face of the medium.

4. The light-transmitting portion is formed by bending a part of the first sheet metal or the second sheet metal, as described in claim 2.

5. The media holding unit has a reference unit provided at a location corresponding to the scanning range of the optical sensor, In the aforementioned intersection direction The reference portion and the light-transmitting portion are located in overlapping positions. The media holding member according to claim 1, wherein the reference portion is formed at the end of the media holding portion.

6. The media holding member according to claim 1, wherein the light-transmitting portion is made of sheet metal and is bent to conform to the shape of the support surface to avoid the irradiated light.

7. The media holding portion is formed from a third sheet metal, The main body portion has the third sheet metal and the fourth sheet metal which is superimposed on the third sheet metal. The media holding member according to claim 6, wherein the media is held between the third sheet metal and the support surface.

8. The media holding portion is formed by bending the sheet metal in a direction away from the support surface so that the media can be sandwiched between it and the support surface, as described in claim 6.

9. A media support section that supports the medium being transported in the transport direction on a support surface, A head for dispensing liquid into the medium supported on the support surface, A head carriage that moves the head in a direction intersecting the conveying direction, An optical sensor mounted on the head carriage and scanned in the intersecting direction for detecting an object to be detected on the support surface, The media holding member comprises a media holding portion that presses the ends of the media in the intersecting direction between itself and the support surface, and a main body portion that supports the media holding portion and is engageable with the media support portion. The printing apparatus is characterized in that the media holding portion or the main body portion has a light-transmitting portion that allows light from the optical sensor to pass through.

10. The printing apparatus according to claim 9, wherein the media support portion has a recess with respect to a position overlapping with the light-transmitting portion.

11. The recess is a groove along the intersecting direction, The printing apparatus according to claim 10, wherein the optical sensor scans along the recess.

12. The printing apparatus according to claim 11, wherein the groove is composed of a surface that extends in a direction intersecting the direction of irradiation of the light at the portion irradiated by the light.

13. The printing apparatus according to claim 9, wherein the light-transmitting portion is an opening.

14. The printing apparatus according to claim 13, wherein the aperture is formed with a width larger than the spot diameter of the irradiated light at the detection position of the optical sensor.

15. The printing apparatus according to claim 13, wherein a plurality of openings are provided along the intersecting direction.

Images