JP6179284B2 - A liquid detection member, a liquid ejection device, and a method for manufacturing the liquid detection member. - Google Patents

Description

  The present invention relates to a liquid detection member for detecting a liquid, a liquid ejection apparatus including the liquid detection member, and a method for manufacturing the liquid detection member.

  Patent Document 1 discloses an image recording apparatus including a plurality of recording heads that discharge a plurality of types of ink including transparent ink. This image recording apparatus has a detection base material for detecting a discharge failure of a recording head, particularly a nozzle for discharging transparent ink. The substrate for detection is ground glass having fine irregularities (rough surface portions) on the surface. Therefore, the light irradiated to the detection substrate is refracted and scattered in various directions by the rough surface portion of the surface of the detection substrate.

  When inspecting the ejection failure of the nozzle that ejects the transparent ink, first, with the recording head and the detection base material facing each other, the nozzle faces the surface on which the rough surface portion of the detection base material is formed. Ink is ejected toward. When ink adheres to the rough surface portion of the detection substrate, the interface between the substrate (ink) and air is smoothed at the portion where the ink is adhered, and light passes straight through the detection substrate. . Therefore, after the transparent ink is ejected from the nozzle toward the detection substrate, the ink is normally ejected from the nozzle by visually checking whether light is transmitted in the area where the ink lands. It can be determined whether or not.

Japanese Patent Application Laid-Open No. 2005-224989

  In the above-mentioned Patent Document 1, on the surface of the base material for detection on which a rough surface portion composed of minute irregularities is formed, most of the light irradiated from the back side of the base material for detection is refracted and scattered in various directions. In a part of the rough surface portion, light passes in the direction in which the eyes of the person who is viewing are located. In other words, even when no ink is attached to the detection base material, a part of the light reaches the human eye, and in some cases, it may be erroneously determined that the ink is attached. is there.

It is an object of the present invention to block light traveling in a predetermined direction through a rough surface portion in a state where no liquid adheres to the rough surface portion in liquid detection using a detection base material having a rough surface portion formed on the surface. It is to prevent false detection.

The liquid detection member according to the first aspect of the present invention is provided with a detection base material made of a light-transmitting material and having a rough surface portion that scatters irradiated light formed on one surface thereof, and the detection base material. And a light shielding portion that blocks light that passes through the rough surface portion and proceeds in a predetermined direction in a state where no liquid adheres to the rough surface portion.

In the present invention, the light passing through the rough surface portion in the predetermined direction is blocked by the light shielding portion provided on the detection base material in a state where no liquid is attached to the rough surface portion of the detection base material. Therefore, it is possible to prevent erroneous detection when detecting light from the predetermined direction to detect the presence or absence of liquid adhering to the detection base material.

  The liquid detection member according to a second aspect of the present invention is the liquid detection member according to the first aspect, wherein the detection base is formed in a plate shape, and the surface opposite to the one surface of the detection base is from the rough surface portion. The surface roughness of the surface of the detection substrate opposite to the one surface, the portion of the rough surface portion in the thickness direction of the detection substrate through which light traveling in the predetermined direction passes, The light shielding portion is formed in the overlapping portion.

  In the present invention, since the light shielding portion is formed on a surface having a surface roughness smaller than that of the rough surface portion on the opposite side to the surface on which the rough surface portion of the base material for detection is formed, it is easy to form the light shielding portion. .

  The liquid detection member according to a third aspect of the present invention is the liquid detection member according to the first aspect, wherein the one surface of the detection base material covers the portion of the rough surface portion through which light traveling in the predetermined direction passes. A portion is formed.

  In the present invention, since the light shielding portion directly covers the portion of the rough surface portion of the detection base material through which the light traveling in the predetermined direction passes, such light is reliably shielded.

According to a fourth aspect of the present invention, there is provided a liquid ejection device including a liquid ejection head having a liquid ejection surface on which a nozzle for ejecting liquid is formed, and an inspection device that detects ejection failure of the nozzle of the liquid ejection head,
The inspection apparatus includes a liquid detection member that is disposed to face the liquid discharge surface of the liquid discharge head and that receives the liquid discharged from the nozzle, and a light emitting unit that emits light toward the liquid detection member. A light receiving unit that detects light emitted from the light emitting unit and transmitted through the liquid detection member and traveling in a predetermined direction,
The liquid detection member is made of a translucent material, and the base material for detection in which a rough surface portion that scatters light emitted from the light emitting portion is formed on a surface facing the liquid discharge surface; A light-shielding portion that is provided on the detection base material and blocks light traveling through the rough surface portion and traveling in the predetermined direction in a state where no liquid is attached to the rough surface portion.

In the present invention, the light passing through the rough surface portion toward the light receiving portion is blocked by the light shielding portion provided on the detection base material in a state where no liquid adheres to the rough surface portion of the detection base material. Thereby, the erroneous detection at the time of detecting the light from the said predetermined direction and detecting whether the liquid discharged from the nozzle has adhered to the base material for a detection can be prevented.

  The manufacturing method of the liquid detection member of 5th invention is a manufacturing method of the liquid detection member of the said 1st invention, Comprising: Light irradiation which irradiates light with respect to the said base material for detection in which the said rough surface part was formed And a light shielding portion forming step of forming the light shielding portion on the detection base material so as to block light that is irradiated to the detection base material and passes through the rough surface portion and proceeds in a predetermined direction. It is characterized by that.

  In the present invention, the detection base material on which the rough surface portion is formed is irradiated with light, and the detection base material is shielded so as to block light traveling through the rough surface portion and traveling in a predetermined direction out of the irradiated light. A light shielding portion is formed on the substrate.

According to a sixth aspect of the present invention, there is provided the method for producing a liquid detection member according to the fifth aspect, further comprising a mask formation step of forming a mask around a portion of the detection base material through which the light traveling in the predetermined direction is transmitted. In the light shielding part forming step, the light shielding part is formed on the surface of the portion of the base material for detection that is not covered with the mask.

  In the present invention, the light shielding portion can be easily formed by forming a mask around a portion of the detection base material through which the light traveling in the predetermined direction is transmitted.

  According to a seventh aspect of the present invention, in the fifth or sixth aspect of the invention, the detection base is formed in a plate shape, and the surface of the detection base opposite to the one surface is The surface roughness is smaller than the rough surface portion, and in the light shielding portion forming step, of the rough surface portion in the thickness direction of the detection base material on the surface opposite to the one surface of the detection base material. The light shielding portion is formed in a portion overlapping with a portion through which light traveling in the predetermined direction passes.

  In the present invention, since the light shielding portion is formed on a surface having a surface roughness smaller than that of the rough surface portion on the side opposite to the surface on which the rough surface portion is formed, the light shielding portion can be easily formed.

  According to an eighth aspect of the present invention, there is provided the method for producing a liquid detection member according to the fifth or sixth aspect, in the light shielding portion forming step, the predetermined direction of the rough surface portion on the one surface of the detection base material. The light-shielding portion is formed so as to cover a portion through which the light traveling to the passage passes.

  In the present invention, since the light shielding portion is formed so as to directly cover the portion of the rough surface portion through which the light traveling in the predetermined direction passes, such light can be reliably shielded by the light shielding portion.

According to the present invention, the light passing through the rough surface portion in a predetermined direction is blocked by the light shielding portion provided on the detection base material in a state where no liquid is attached to the rough surface portion of the detection base material. Therefore, it is possible to prevent erroneous detection when detecting light from the predetermined direction to detect the presence or absence of liquid adhering to the detection base material.

1 is a schematic plan view of a printer according to an embodiment. It is the II-II sectional view taken on the line of the printer of FIG. FIG. 2 is a block diagram schematically illustrating an electrical configuration of a printer. FIG. 3 is a cross-sectional view corresponding to FIG. 2 of the printer at the time of ejection inspection. It is a figure explaining the principle of the ejection defect detection by an inspection apparatus. It is a partial expanded sectional view of an ink detection member. It is a flowchart of a discharge inspection. It is a figure which shows the manufacturing process of an ink detection member. It is a partially expanded sectional view of the ink detection member which concerns on a change form. It is a figure which shows the structural example for removing ink from the base material for a detection based on another modification. It is a schematic plan view of the printer which concerns on another modification. It is a figure which shows the ink tank which concerns on another modification, (a) is a side view of an ink tank, (b) is the BB sectional drawing of (a).

  Next, an embodiment of the present invention will be described. The present embodiment is an example in which the present invention is applied to an ink jet printer that records an image or the like by ejecting ink onto a recording sheet conveyed in a predetermined conveyance direction. FIG. 1 is a schematic plan view of the printer according to the present embodiment. 2 is a cross-sectional view taken along the line II-II of the printer of FIG. 1, and FIG. 3 is a block diagram schematically showing the electrical configuration of the printer. 1 is defined as the front-rear direction of the printer 1, the left-right direction in FIG. 1 is defined as the left-right direction of the printer 1, and the vertical direction in FIG. 1 is defined as the up-down direction of the printer 1 (the front side of the page is upward). In the following, description will be made using direction words such as front and rear, left and right, and up and down as appropriate.

(Printer configuration)
As shown in FIGS. 1 to 3, the printer 1 includes a platen 2, an inkjet head 3, two transport rollers 4 and 5, a purge pump 6, an inspection device 7, a control device 8, and the like. .

  The platen 2 has two plate-like members 2a and 2b arranged in the front-rear direction. The two plate-like members 2a and 2b are respectively driven by an opening / closing mechanism (not shown) so as to be able to take a horizontal posture and a turning posture that is rotated downward with respect to the horizontal posture such as a double opening. It is configured. As shown in FIGS. 1 and 2, when the two plate-like members 2a and 2b are in the horizontal posture, the recording paper 100 is placed on the upper surfaces of the two plate-like members 2a and 2b. Note that an inspection device 7 described later is accommodated in a space below the platen 2.

  The inkjet head 3 is a line-type head that is long in the paper width direction. The ink jet head 3 is connected to an ink tank (not shown), and ink is supplied from the ink tank. A plurality of nozzles 10 arranged in two rows along the longitudinal direction (paper width direction) are formed on the lower surface of the inkjet head 3. Hereinafter, the lower surface of the inkjet head 3 on which the plurality of nozzles 10 are formed is referred to as an ink ejection surface 3a.

  The two transport rollers 4 and 5 are arranged so as to sandwich the ink jet head 3 in a direction (transport direction) orthogonal to the longitudinal direction of the ink jet head 3. These two transport rollers 4 and 5 are rotationally driven in synchronization by a transport motor 12 (see FIG. 3), and transport the recording paper 100 in the transport direction.

  The inkjet head 3 ejects ink from the plurality of nozzles 10 on the ink ejection surface 3a to the recording paper 100 conveyed in the conveyance direction by the two conveyance rollers 4 and 5, respectively. Print text and images.

  As shown in FIG. 2, the purge pump 6 is disposed between the inkjet head 3 and an ink tank (not shown). The purge pump 6 pressurizes the ink from the ink tank and supplies it to the inkjet head 3, thereby forcibly discharging the ink by pushing it out from the plurality of nozzles 10 of the inkjet head 3. The ink discharging operation from the nozzle by the purge pump 6 is hereinafter referred to as “purge”. By the above purging, foreign matter and air mixed in the ink jet head 3 or ink thickened by drying are discharged from the nozzle 10, and the ejection failure of the nozzle 10 can be solved. Note that the ink discharged from the plurality of nozzles 10 by the purge is collected by an ink receiving member (not shown) disposed opposite to the ink ejection surface 3a of the inkjet head 3.

  The inspection device 7 detects whether or not ejection failure has occurred for each nozzle 10 of the inkjet head 3. FIG. 4 is a cross-sectional view corresponding to FIG. 2 of the printer during the ejection inspection. As shown in FIGS. 2 and 4, the inspection device 7 includes an ink detection member 13 and a transmissive photosensor 14.

  As shown in FIG. 2, the inspection device 7 stands by in a space below the platen 2 when the two plate-like members 2 a and 2 b of the platen 2 are in a horizontal posture. On the other hand, when inspecting the ejection failure of the inkjet head 3, the two plate-like members 2 a and 2 b of the platen 2 rotate in a double-opening manner, and the inspection device 7 is exposed. From this state, the inspection apparatus 7 is further driven by an elevating mechanism (not shown) and ascends to a height position substantially the same as the platen 2 in the closed state, as shown in FIG. As a result, the distance from the ink ejection surface 3a of the inkjet head 3 to the ink detection member 13 is substantially the same as the distance from the ink ejection surface 3a to the recording paper 100 during printing in FIG.

  The ink detection member 13 includes a plate-shaped detection base material 15 made of a light-transmitting material such as glass and having an upper surface and a lower surface that are parallel to each other. The plate-shaped detection substrate 15 is arranged in a horizontal posture so as to be parallel to the ink ejection surface of the inkjet head. As shown in FIG. 4, at the time of ejection inspection, ink ejected from each of the plurality of nozzles 10 of the inkjet head lands on the upper surface of the detection base material 15.

  The photosensor 14 detects ink that has landed on the upper surface of the detection base material 15, and is attached to the detection base material 15 so as to be movable in the left-right direction. More specifically, the photosensor 14 is driven by a sensor drive motor 20 (see FIG. 3) and scans in the left-right direction, that is, the nozzle arrangement direction. Thereby, the presence or absence of ink is detected in order for the plurality of landing areas 21 on the upper surface of the detection substrate 15 where the ink ejected from the plurality of nozzles 10 lands, respectively.

  The photosensor 14 includes a light emitting unit 16 and a light receiving unit 17 held by a holder 18. As shown in FIG. 1, two sets of the light emitting unit 16 and the light receiving unit 17 are provided corresponding to the two nozzle rows, respectively. The light emitting unit 16 is positioned below the detection base material 15. The light emitting unit 16 irradiates light on the lower surface of the detection base material 15 in a direction orthogonal to the lower surface (that is, the thickness direction of the detection base material 15). The light source of the light emitting unit 16 is not particularly limited. For example, the wavelength of light irradiated on the light emitting unit 16 is not particularly limited, and may be light in any range of ultraviolet light, visible light, and infrared light. However, a laser light source with high light directivity can be suitably used so that each landing region 21 of the ink detection member 13 can be irradiated locally. The light receiving unit 17 is disposed on the upper side of the detection base material 15 at a position facing the light emitting unit 16 with the detection base material 15 interposed therebetween. The light receiving unit 17 receives the light transmitted upward from the light emitting unit 16 through the detection base material 15 and travels upward, and outputs an output signal corresponding to the intensity of the received light. Output to the control unit.

  The ink detection member 13 will be described in detail. FIG. 5 is a diagram for explaining the principle of ejection failure detection by the inspection device 7. 5A shows a state in which ink is not ejected to the ink detection member 13, and FIG. 5B shows a state in which ink is ejected to the ink detection member 13. 5A and 5B, a perspective view of the inspection device 7 is shown on the upper side, and a partially enlarged sectional view of the ink detection member 13 is shown on the lower side.

  As shown in FIG. 5, a rough surface portion made of minute irregularities is formed on the upper surface of the plate-shaped detection base material 15 of the ink detection member 13 that faces the ink ejection surface 3 a by roughening. 15a is formed. The rough surface portion 15a may be formed over the entire upper surface of the ink detection member 13, or may be locally formed only in the landing region 21 where a part of the upper surface of the ink ejected from the nozzle 10 is landed. Good.

  In FIG. 5A, a part of the detection substrate 15 from the light emitting unit 16 disposed below the detection substrate 15 in a state where the ink I is not attached to the upper surface of the detection substrate 15. Light is radiated at right angles to a region (a region sandwiched between two two-dot chain lines in the figure below). Here, the upper surface of the detection base material 15 is formed with a rough surface portion 15a made of minute irregularities, so that the upper surface is inclined in various directions with respect to the direction orthogonal to the light traveling direction. There are countless minute inclined surfaces. Accordingly, the light irradiated from below and transmitted through the detection base material 15 is refracted and scattered in various directions on the rough surface portion 15 a on the upper surface of the detection base material 15. Accordingly, the intensity of light reaching the light receiving unit 17 is reduced.

  On the other hand, in FIG. 5B, light is emitted from the light emitting unit 16 to the detection base material 15 with the ink I attached to the upper surface of the detection base material 15. In general, comparing the refractive index of ink with the refractive index of air, the ink is much closer to the refractive index of a transparent material such as glass forming the detection substrate 15. For example, taking water-based ink as an example, the refractive index of water, which is the main component of the ink, is 1.3330, the refractive index of air is 1.0003, and the refractive index of glass is 1.4585. . Therefore, when the ink I adheres to the rough surface portion 15a of the detection base material 15, the light travels straight without being refracted at the interface between the detection base material 15 and the ink. When the ink is a colored ink, the light adhering to the rough surface portion 15a is somewhat blocked by the ink adhering to the rough surface portion 15a. However, even in the case of colored ink, the light shielding property is not so high in a state containing a large amount of moisture (state before drying). Therefore, the influence of the colored ink on the passage of light in the detection base material 15 is considerably smaller than the light scattering in the rough surface portion 15a. Therefore, even if the ink adhering to the rough surface portion 15a is a colored ink, the intensity of light detected by the light receiving unit 17 is higher than that in a state where no ink is adhering.

  On the other hand, at the interface between the detection substrate 15 (ink I) and the air, the refractive indexes of the two are greatly different. Therefore, if light is incident on the direction orthogonal to the interface, Light is refracted. However, as shown in FIG. 5B, the interface between the detection substrate 15 (ink I) and air is smoothed by the ink I attached to the detection substrate 15. For this reason, the light emitted from the light emitting unit 16 enters the interface almost perpendicularly, and proceeds straight without being refracted at the interface. As described above, the ink I adheres to the rough surface portion 15a, so that light is hardly scattered by the rough surface portion 15a, and most of the light that has passed through the rough surface portion 15a travels toward the upper light receiving portion 17. Thereby, the intensity of the light detected in the light receiving unit 17 becomes stronger than that in FIG.

  By the way, although the light irradiated from the light emission part 16 is scattered in the upper surface of the base material 15 for detection in which the rough surface part 15a was formed as mentioned above, the light which passed the rough surface part 15a does not reach the light-receiving part 17 at all. That's not to say. FIG. 6 is a partially enlarged cross-sectional view of the ink detection member 13. As shown in FIG. 6A, the rough surface portion 15a locally has a surface substantially orthogonal to the light traveling direction. Therefore, even when the detection base material 15 is not attached with ink, a part of the light irradiated from below passes straight through the rough surface portion 15a and proceeds upward. When such a light is received by the light receiving unit 17 located immediately above the light emitting unit 16, there is a possibility that the ink is erroneously detected when the ink is attached to the detection base material 15 although the ink is not present. There is.

In this regard, the ink detection member 13 of the present embodiment includes the light shielding portion 19 that blocks the light that passes through the rough surface portion 15 a and travels toward the light receiving portion 17. As shown in FIG. 6B, the lower surface of the detection substrate 15 is a smooth surface having a smaller surface roughness than the upper surface on which the rough surface portion 15a is formed. In the thickness direction of the detection base material 15 in the lower surface of the detection base material 15, the light shielding portion 19 is overlapped with a region that overlaps a portion of the rough surface portion 15 a through which light toward the upper light receiving portion 17 passes. Is formed. The material of the light shielding portion 19 is not particularly limited as long as it can block light, but can be formed of, for example, metal, colored resin, or the like. As described above, the light that passes through the rough surface portion 15a toward the light receiving portion 17 is blocked by the light shielding portion 19 provided on the detection base material 15 in a state where the ink is not attached to the rough surface portion 15a.

  Returning to FIGS. 1 and 2, a wiper 22 for wiping off ink adhering to the upper surface of the base material 15 for detection is disposed in the space below the platen 2 on the right side of the ink detection member 13. . The wiper 22 includes a wiper blade 23 made of a flexible material such as rubber, and a holder 24 that holds the wiper blade 23. The wiper 22 is driven in the left-right direction by a wiper drive motor 25 (see FIG. 3). As shown in FIG. 2, the ink that has landed on the upper surface of the detection substrate 15 is wiped by moving the wiper 22 to the left and right in a state where the ink detection member 13 is positioned below the platen 2. It is wiped off by the blade 23.

  As shown in FIG. 3, the control device 8 includes a CPU (Central Processing Unit) 30, a ROM (Read Only Memory) 31, a RAM (Random Access Memory) 32, and an ASIC (Application Specific Integrated Circuit) including various control circuits. 33 and the like. The control device 8 is connected to the inkjet head 3, the conveyance motor 12, the purge pump 6, the photo sensor 14 of the inspection device 7, the sensor drive motor 20, the wiper drive motor 25, and the like. The control device 8 is also connected to an operation panel 26, a PC 27 that is an external device, and the like.

  The control device 8 causes the CPU 30 and the ASIC 33 to execute various processes according to the program stored in the ROM 31. For example, the control device 8 controls the inkjet head 3 and the transport motor 12 based on a print command transmitted from the PC 27 to print an image or the like on the recording paper 100. In addition, the inkjet head 3 and the inspection device 7 are controlled to perform ejection inspection on each nozzle 10 of the inkjet head 3. Further, when a discharge failure of the nozzle 10 is detected, the purge pump 6 is controlled to perform maintenance for eliminating or preventing the discharge failure of the inkjet head 3. Although not shown, the control device 8 operates a motor or the like for each of an opening / closing mechanism that rotates the plate-like members 2a and 2b (see FIG. 1) of the platen 2 and an elevating mechanism that elevates and lowers the inspection device 7. The operation of the unit is also controlled.

  In the above description, an example in which the control device 8 performs various processes by the CPU and the ASIC has been described. However, the present invention is not limited to this, and the control device 8 can be realized by any hardware configuration. Good. For example, the processing may be shared by two or more ICs such as a CPU and an ASIC. Further, the operation of the printer 1 based on the above-described program may be controlled with only one IC chip.

(Discharge inspection)
Next, the discharge inspection by the inspection apparatus 7 will be described in detail. FIG. 7 is a flowchart of the discharge inspection. In FIG. 7, Si (i = 10, 11, 12,...) Indicates a step number.

  When a signal for requesting a discharge inspection of the inkjet head 3 is input to the control device 8 by operating the operation panel 26 or the like, the control device 8 executes the following discharge inspection process. Note that the timing for performing the ejection inspection is not limited to a request from the user. For example, the discharge inspection may be periodically performed by inputting a request signal every certain period of time.

  First, when performing the ejection inspection, the control device 8 controls the opening / closing mechanism of the platen 2, the lifting mechanism of the inspection device 7, and the like, as shown in FIG. 4, raises the inspection device 7 to the ink ejection surface 3a. Move closer. In this state, the control device 8 controls the inkjet head 3 to eject ink from the plurality of nozzles 10 toward the ink detection member 13 of the inspection device 7 (S10).

  When ink is ejected to the ink detection member 13, the control device 8 controls the opening / closing mechanism of the platen 2, the lifting mechanism of the inspection device 7, and the like, as shown in FIG. Keep away from 3a. In this state, the control device 8 controls the sensor drive motor 20 to move the photosensor 14 in the left-right direction while irradiating light from the light emitting unit 16 toward the detection base material 15. At this time, the light receiving unit 17 linearly moves the detection base material 15 from the light emitting unit 16 in each of the plurality of landing areas 21 on the upper surface of the detection base material 15 where the inks from the plurality of nozzles 10 respectively land. Light that passes through and travels upward is received. Thereby, the ink adhering to the landing area 21 is detected (S11).

  A signal corresponding to the intensity of the received light is output from the light receiving unit 17 to the control device 8. The control device 8 determines the presence or absence of ejection failure for each of the plurality of nozzles 10 based on the output from the light receiving unit 17 (S12). Specifically, if the intensity of light received by the light receiving unit 17 is greater than or equal to a certain landing area 21, light adheres to the detection base material 15 because ink has adhered to the landing area 21. It is determined that the nozzle 10 corresponding to the landing region 21 is ejecting ink normally, assuming that it is transmitted in a straight line. On the other hand, when the intensity of light received by the light receiving unit 17 is less than a certain value for a certain landing region 21, light is scattered on the rough surface portion 15a of the detection base material 15 because no ink is attached. As a result, it is determined that a discharge failure has occurred in the nozzle 10 corresponding to the landing area 21.

  Here, in the present embodiment, as described above, the light shielding portion 19 is provided on the detection base material 15. Therefore, when ink does not adhere to the landing area 21, the light that passes straight through the rough surface portion 15 a and travels toward the light receiving portion 17 is blocked by the light shielding portion 19. Therefore, light that is received by the light receiving unit 17 even though no ink is attached can be reduced, and erroneous detection can be prevented.

  If the ink is left on the ink detection member 13, the ink adheres and remains, which may cause a false detection or the like in the next ejection inspection. Therefore, when the ink detection (S11) by the photosensor 14 is completed, the control device 8 controls the wiper drive motor 25 to move the wiper 22 in the left-right direction so that the ink attached to the ink detection member 13 is wiped off. (S13).

  Note that the above-described ejection inspection need not be performed for all the nozzles 10 of the inkjet head 3 at a time. For example, all the nozzles 10 of the inkjet head 3 may be divided into several groups, and the ejection inspection may be performed for each group. Alternatively, the discharge inspection may be performed only for some of the nozzles 10.

  When it is detected by the above-described discharge inspection that a discharge failure has occurred in any of the nozzles 10, the control device 8 controls the purge pump 6 to execute the purge, thereby causing the discharge failure of the nozzle 10. To eliminate. Further, in order to eliminate the ejection failure, flushing may be performed in which the ink is continuously ejected a plurality of times from the nozzle 10 instead of the purge.

(Method for manufacturing ink detection member)
Next, a method for manufacturing the above-described ink detection member 13 will be described. Below, the process of forming the light shielding part 19 will be mainly described. In the present embodiment, the light shielding portion 19 is formed using a mask. The type of the mask is not particularly limited, but here, an example in which a method of forming a mask using a resist is employed. That is, after forming a mask with a resist around a portion of the detection base material 15 where light passing through the rough surface portion 15a and transmitting upward is transmitted, the light shielding portion 19 is provided on the surface of the portion not covered with the mask. Then, the resist is peeled off.

  Hereinafter, specific description will be given with reference to the drawings. FIG. 7 is a diagram illustrating a manufacturing process of the ink detection member 13. First, as shown in FIG. 7A, a resist film 40 is formed on a smooth surface opposite to the surface on which the rough surface portion 15a is formed of the base material 15 for detection. In addition, the resist includes a positive type in which the solubility in the solution is increased by exposure, and conversely, a negative type in which the solubility is decreased by the exposure. Here, any type of resist may be used. Now, a case where a positive resist is used will be described as an example.

  Next, as shown in FIG. 7 (b), a light emission source (not shown) is arranged on the surface side (lower side in the figure) where the rough surface portion 15a is formed with respect to the base material 15 for detection to emit light. Light is irradiated from the source to the rough surface portion 15 a of the detection base material 15 in the thickness direction of the detection base material 15. At this time, the light emitted from the light source is scattered by the rough surface portion 15a, but a part of the light passes straight through the rough surface portion 15a and further passes through the inside of the detection base material 15 to be on the opposite side. The resist film 40 formed on the surface is reached. Thereby, with respect to the thickness direction of the base material 15 for detection, the resist film 40 is locally exposed in a portion of the rough surface portion 15a that overlaps a portion through which upward light passes.

  Next, as shown in FIG. 7C, the exposed portion 40a of the resist film 40 is removed by dissolving it with a dedicated solution. Then, as shown in FIG. 7D, the entire surface of the detection base material 15, that is, the entire surface including the surface of the resist film 40 and the region not covered with the resist film 40 of the detection base material 15. Then, a light shielding film 41 made of a light shielding material is formed. The material of the light shielding film 41 and the film forming method thereof can be appropriately selected from known ones. For example, when a metal is used as a film forming material, the film can be formed by sputtering or vapor deposition. Finally, as shown in FIG. 7E, by removing the resist film 40, only the portion of the light shielding film 41 that is not covered with the resist film 40 remains, and this remaining film portion Becomes the light shielding portion 19.

  In addition, when the light directivity of the light emitting source used when forming the light shielding portion 19 and the light directivity of the light emitting portion 16 of the photosensor 14 are greatly different, the light source is irradiated. The position where light passes straight through the rough surface portion 15a differs depending on whether the light is emitted from the light emitting portion 16 of the photosensor 14. That is, there is a possibility that the light shielding portion 19 is not formed at a position where it is desired to block light. For this reason, it is preferable to use a light emitting source having a light directivity of approximately the same level as that of the light emitting portion 16 of the photosensor 14.

  In the present embodiment, the light shielding portion 19 is formed on a surface having a smaller surface roughness than the rough surface portion 15a on the side opposite to the surface on which the rough surface portion 15a of the detection base material 15 is formed. As compared with the case where the light shielding portion 19 is formed on the surface on which the surface portion 15a is formed, the light shielding portion 19 can be easily formed. For example, as described above, when the method of forming a mask with the resist film 40 is adopted, it is easy to form the layer of the resist film 40 on the surface of the detection base material 15 with a uniform thickness, Removal of the exposed portion 40a and peeling of the resist film 40 are easy.

  In the embodiment described above, the printer 1 corresponds to the liquid ejection apparatus of the present invention. The ink jet head 3 corresponds to the liquid discharge head of the present invention. The ink discharge surface 3a corresponds to the liquid discharge surface of the present invention. The ink detection member 13 corresponds to the liquid detection member of the present invention.

  Next, modified embodiments in which various modifications are made to the embodiment will be described. However, components having the same configuration as in the above embodiment are given the same reference numerals and description thereof is omitted as appropriate.

1] The light shielding portion 19 provided on the detection base material 15 is not limited to that of the above embodiment. For example, as shown in FIG. 9, the light shielding portion covers the portion of the rough surface portion 15a through which the light toward the upper light receiving portion 17 passes on the surface where the rough surface portion 15a of the detection base material 15 is formed. 19 may be formed. Thus, since the light shielding portion 19 directly covers the portion of the rough surface portion 15a of the detection base material 15 through which the light toward the light receiving portion 17 passes, such light is reliably blocked. However, as shown in FIG. 6 of the above-described embodiment, compared to the case where the light shielding portion 19 is formed on a smooth surface having a small surface roughness, the light shielding portion 15a having a large surface roughness is shielded. The process of forming the part 19 is somewhat difficult.

  Further, the light shielding portion 19 may be provided inside the detection base material 15 instead of the surface of the detection base material 15. For example, the detection base material 15 has a translucent plate having a rough surface portion formed on one surface thereof, and a smooth translucent plate on both surfaces thereof, and these two plates are the rough plate. It is assumed that the structures are superposed on each other so that the surface portions are located outside. In such a structure, the light shielding portion 19 may be disposed between the two plates.

2] In the above embodiment, the light emitting unit 16 of the photosensor 14 irradiates light in a direction orthogonal to the detection base material 15, but the light emitting unit 16 applies the light to the detection base material 15. Light may be irradiated in a direction inclined with respect to the orthogonal direction. In this embodiment, similarly to the above-described embodiment, when the light shielding portion 19 is formed using a resist mask, the light for exposing the resist is also in the orthogonal direction as in the light emitting portion 16 of the photosensor 14. Irradiate in a direction inclined with respect to. Moreover, in the said embodiment, although the base material 15 for a detection of the ink detection member 13 was a plate-shaped member, the shape of the base material 15 for a detection is not specifically limited. For example, even if the thickness of the base material for detection 15 is not constant and the surface on which the light from the light emitting portion 16 is incident and the surface on which the light transmitted through the detection base material 15 is emitted are not parallel to each other Good.

  In the above embodiment, the surface on which the rough surface portion 15 a of the detection base material 15 is formed may not be orthogonal to the traveling direction of light transmitted through the detection base material 15. In this case, when the ink adheres to the rough surface portion 15a, the light does not pass straight through the rough surface portion 15a, but at the incident angle of light to this interface at the interface between the ink and air. Refraction occurs at an appropriate angle. Even in such a case, if the light receiving unit 17 is disposed ahead of the direction in which the light after refraction travels, it is possible to detect the transmitted light when the ink is attached. Further, the light is scattered when the ink does not adhere to the rough surface portion 15a, but the light shielding portion 19 is the direction in which the light receiving portion 17 is arranged in the light passing through the rough surface portion 15a. It is provided so as to block light traveling in the direction of refraction when ink is attached.

3] In the above-described embodiment, the inspection device 7 inspects whether or not the nozzle 10 is not ejected as an ejection failure of the nozzle 10, but the ejection direction is tilted with respect to the normal direction and the ejection direction is tilted or not. It is also possible to inspect.

  If the ejection direction of the nozzle 10 is inclined, the landing position of the ink discharged from the nozzle 10 on the detection base material 15 is shifted from the landing position when the discharge direction is normal. Therefore, when the photosensor 14 is moved in the left-right direction with respect to the detection base material 15 by the sensor drive motor 20 while irradiating light from the light emitting unit 16, the ink lands on the upper surface of the detection base material 15. In addition to detecting whether or not the ink has landed, the ejection direction inclination in the left-right direction can be detected. If the photosensor 14 is moved in the front-rear direction with respect to the detection base material 15, it is possible to detect the ejection direction inclination in the front-rear direction.

4] Since the rough surface portion 15a is formed on the upper surface of the detection base material 15, the ink adhering to the detection base material 15 is difficult to remove. Therefore, the following configuration can also be adopted so that the ink can be removed more reliably.

  As shown in FIG. 10A, a plurality of grooves 15 b may be formed on the upper surface of the detection base material 15. In this case, when the upper surface of the substrate for detection 15 is wiped with the wiper blade 23, the ink flows along the groove 15b, so that the wipe can be more reliably wiped off.

  Instead of the wiper blade 23, as shown in FIG. 10B, the rotating body 42 having a large number of blades 42a may be removed by blowing off the ink on the upper surface of the detection substrate 15. In this case, it is preferable that a scattering prevention member 43 for preventing the blown-off ink from being scattered around is provided around the detection base material 15. Further, as shown in FIG. 10C, the ink may be wiped off by moving the sponge 44 having high absorbency with respect to the base material 15 for detection.

  As shown in FIG. 10 (d), the air may be blown off by blowing air onto the upper surface of the detection substrate 15 by the air blowing device 45. The air blowing device 45 moves in the surface direction with respect to the detection base material 15. Further, it is preferable to provide a scatter preventing member 46 that prevents the ink blown off with air from being scattered around. In particular, in order to prevent the blown-off ink from adhering to the ink ejection surface 3 a of the inkjet head 3, the scattering prevention member 46 is desirably provided above the detection base material 15. Further, warm air may be blown against the detection base material 15. It is preferable in terms of energy efficiency that the warm air is generated using heat generated inside the printer 1.

4] The printer 1 of the above embodiment has a line-type inkjet head having a plurality of nozzles 10 arranged in the width direction of the recording paper. However, the printer 1 has a serial-type inkjet head. Also, the present invention can be applied.

As shown in FIG. 11, the printer 51 includes a carriage 52, an inkjet head 53, conveyance rollers 54 and 55, an inspection device 57, a control device 58, and the like. The carriage 52 is driven via a belt 61 by a carriage drive motor 59 and reciprocates in the scanning direction (left-right direction). The inkjet head 53 is mounted on the carriage 52. This ink jet head 53, the tube four ink from the ink tank 6 2 connected with (not shown) is supplied. The inkjet head 53 ejects ink from the plurality of nozzles 60 to the recording paper 100 placed on the platen 56 while moving in the scanning direction together with the carriage 52.

  The inspection device 57 includes an ink detection member 63 disposed on the right side of the platen 56 and a photosensor (not shown). Although not shown, the ink detection member 63 includes a detection base material having a rough surface portion and a light shielding portion, similarly to the ink detection member 13 (see FIGS. 5 and 6) of the above-described embodiment. . As the carriage 52 moves in the scanning direction, the ink ejection surface of the inkjet head 53 faces the ink detection member 63 and the plurality of nozzles 60 of the inkjet head 53 face the detection substrate of the ink detection member 63. Ink is ejected. Then, the presence or absence of ejection failure can be detected for each of the plurality of nozzles 60 by detecting the ink adhering to the detection base material by the photosensor.

5] In the above embodiment, the printer 1 is provided with the ink detection member 13 for inspecting the ejection failure of the nozzles 10. However, this is not always necessary. For example, before the printer is shipped, an ink detection member is temporarily attached to each printer, ink is ejected to the ink detection member, the ink detection member is removed, and an ejection failure is detected by a device other than the printer. You may go. Further, it is not necessary to set an ink detection member from which ink has been ejected to a special device to determine ejection failure. That is, for example, a person can irradiate the ink detection member with light from a portable light source and visually check the transmitted light from the opposite side of the light source to determine the presence or absence of ejection failure. it can.

6] In the above-described embodiment, the ink detection member is used to detect nozzle ejection defects, but can be used for inspections other than ejection defects. Any other inspection can be used as long as it can utilize the fact that the ink adheres to the detection substrate.

  For example, it can be used for detecting the remaining amount of ink in the ink tank. 12A is a side view of the ink tank, and FIG. 12B is a cross-sectional view taken along line BB in FIG. The ink tank 70 has a tank body 71 made of a synthetic resin material having translucency. Ink I is stored in the tank body 71. The ink tank 70 is detachably attached to a printer-side holder (not shown). The holder has a transmissive photosensor 72 for detecting the remaining amount of ink in the ink tank 70. When the ink tank 70 is attached to the holder, the tank body 71 is inserted between the light emitting unit 73 and the light receiving unit 74 of the photosensor 72.

  As shown in FIG. 12B, a rough surface portion 76 a is formed on the inner surface of the irradiated portion 76 that is irradiated with light from the light emitting portion 73 in the side wall portion 75 of the tank body 71. In this modified embodiment, the side wall portion 75 corresponds to the liquid detection member of the present invention, and the irradiated portion 76 corresponds to the detection base material of the present invention. As shown in FIG. 12B, in a state where the ink I is sufficiently stored in the tank main body 71, the ink I is in contact with the rough surface portion 76 a on the inner surface of the irradiated portion 76. Further, on the outer surface of the irradiated portion 76, a light shielding portion 77 is provided that blocks light that passes straight through the rough surface portion 76a in a state where the ink I is not in contact with the inner surface of the irradiated portion 76. In addition, the light-shielding part 77 may be provided in the side wall part 78 which does not have a rough surface part by the light-receiving part 74 side (left side in FIG.12 (b)).

In a state where the ink I is sufficiently in the tank main body 71 and the ink I is in contact with the rough surface portion 76a, most of the light irradiated to the irradiated portion 76 passes straight through the rough surface portion 76a, and the light receiving portion 74. Is received. On the other hand, when the ink I in the tank body 71 decreases and the ink I does not contact the rough surface portion 76a, most of the light irradiated to the irradiated portion 76 is scattered by the rough surface portion 76a. The intensity of the emitted light is low. Further, the light shielding portion 77 provided on the outer surface of the irradiated portion 76 blocks light traveling straight through the rough surface portion 76a toward the light receiving portion 74 in a state where ink is not attached to the rough surface portion 76a. This reliably prevents erroneous detection that ink I is in contact with ink I that is not in contact with the inner surface of the irradiated portion 76.

DESCRIPTION OF SYMBOLS 1 Printer 3 Inkjet head 3a Ink ejection surface 7 Inspection apparatus 10 Nozzle 13 Ink detection member 14 Photo sensor 15a Rough surface part 15 Detection base material 16 Light emission part 17 Light reception part 19 Light-shielding part 51 Printer 53 Inkjet head 57 Inspection apparatus 60 Nozzle 63 Ink Detection member 70 Ink tank 72 Photo sensor 73 Light emitting part 74 Light receiving part 75 Side wall part 76 Irradiated part 76a Rough surface part 77 Light shielding part

Claims (8)

A detection base material made of a translucent material and having a rough surface portion for scattering irradiated light on one surface thereof;
A light-shielding portion that is provided on the base material for detection and blocks light traveling through the rough surface portion and traveling in a predetermined direction in a state where no liquid is attached to the rough surface portion;
A liquid detection member comprising: The detection substrate is formed in a plate shape,
The surface opposite to the one surface of the substrate for detection has a smaller surface roughness than the rough surface portion,
The light shielding portion is formed on a portion of the surface opposite to the one surface of the detection base material that overlaps a portion of the rough surface portion where light traveling in the predetermined direction passes in the thickness direction of the detection base material. The liquid detection member according to claim 1, wherein the liquid detection member is formed.   The said light-shielding part is formed in the said one surface of the said base material for a detection so that the part through which the light which goes to the said predetermined direction among the said rough surface parts passes may be formed. Liquid detection member. A liquid ejection head having a liquid ejection surface on which nozzles for ejecting liquid are formed, and an inspection device for inspecting ejection failure of the nozzles of the liquid ejection head,
The inspection device includes:
A liquid detection member disposed opposite to the liquid discharge surface of the liquid discharge head and landed by the liquid discharged from the nozzle; a light emitting unit that emits light toward the liquid detection member; and the light emitting unit A light receiving portion that detects light that is irradiated and passes through the liquid detection member and travels in a predetermined direction, and
The liquid detection member is
A detection base material made of a translucent material and having a rough surface portion that scatters light emitted from the light emitting portion formed on a surface facing the liquid ejection surface;
A liquid ejecting apparatus, comprising: a light shielding portion that is provided on the detection base material and blocks light traveling through the rough surface portion and traveling in the predetermined direction in a state where no liquid is attached to the rough surface portion. . It is a manufacturing method of the liquid detection member according to claim 1,
A light irradiation step of irradiating light to the detection base material on which the rough surface portion is formed;
A light-shielding part forming step for forming the light-shielding part on the detection base material so as to block the light that is irradiated to the detection base material and passes through the rough surface part and proceeds in a predetermined direction;
A method for producing a liquid detection member, comprising: Further comprising a mask forming step of forming a mask around a portion of the detection base material through which light traveling in the predetermined direction passes,
The method for producing a liquid detection member according to claim 5, wherein, in the light shielding portion forming step, the light shielding portion is formed on a surface of a portion of the detection base material that is not covered with the mask. The detection substrate is formed in a plate shape, and the surface opposite to the one surface of the detection substrate has a smaller surface roughness than the rough surface portion,
In the light shielding portion forming step, a portion of the surface opposite to the one surface of the detection base material through which light traveling in the predetermined direction in the rough surface portion in the thickness direction of the detection base material passes. The method for manufacturing a liquid detection member according to claim 5, wherein the light shielding portion is formed in an overlapping portion.   The light shielding portion is formed in the light shielding portion forming step so as to cover a portion of the rough surface portion through which light traveling in the predetermined direction passes on the one surface of the detection base material. Item 7. A method for producing a liquid detection member according to Item 5 or 6.

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