JP2005313449A - Liquid storing member and liquid consuming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a liquid quantity at a plurality of detection positions in a liquid storing member by a simple constitution. <P>SOLUTION: A prism part 66 consists of an incidence waveguide 66a for guiding light brought in nearly parallel to an axial direction from an incidence part 67 to the downstream side, and an emission waveguide 66b for guiding the light from the incidence waveguide 66a side to an emission part 68 side. At the same time, the prism part 66 has a plurality of detecting parts 70 halfway each as an inclined face inclined to the axial direction of the incidence waveguide 66a. Each detecting part 70 is arranged at the detection position made different in the height in an ink storage part 58, and is set in a state to pass a large part of the light entering from the incidence waveguide 66a to the ink side when in a soak state in which the detecting part 70 soaks in the ink, and to reflect the large part of the entering light as a liquid quantity detection light to the emission waveguide 66b side when in a non soak state in which the detecting part 70 does not soak in the ink. An emitting quantity of light of the emission part 68 is made to change according to the soak state or the non soak state of each detecting part 70. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid storage member that stores a liquid such as ink, and a liquid consuming device such as an ink jet printer. In particular, the liquid amount can be detected using an optical sensor including a light emitting element and a light receiving element. The present invention relates to a liquid storage member and a liquid consumption device.

  As a liquid consuming device that consumes liquid, for example, a liquid ejecting head capable of ejecting liquid as droplets is provided, and liquid ink is ejected from the liquid ejecting head as ink droplets onto an ejection target such as recording paper. An image recording apparatus such as an ink jet printer that performs recording by landing can be used.

  In general, this type of liquid consuming apparatus is configured to detachably mount a liquid storage member that stores liquid, and discharge the liquid in the liquid storage member as droplets from a liquid ejecting head. is there. When the remaining amount of the liquid in the liquid storage member becomes small (hereinafter referred to as near end), the user can grasp the replacement timing of the liquid storage member so that the user can grasp the replacement timing. It is desirable to adopt a configuration for notifying the user of the remaining amount of liquid.

  Various means have been proposed as means for detecting the remaining amount of liquid in the liquid storage member. For example, a transparent light transmission window is provided on each of the opposing walls of the ink tank as a liquid storage member, a light emitting element that emits light into the ink tank through the light transmission window, and an ink that is emitted from the light emitting element An optical system (light sensor) that includes a light receiving element that receives light passing through the tank and that detects the remaining amount of ink in the ink tank based on a change in the amount of light received by the light receiving element has been proposed. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 62-156963

In the configuration disclosed in Patent Document 1, the position (detection position) where the remaining amount of ink can be detected is limited to one location. That is, the remaining amount of ink can be detected only in the portion where the light from the light emitting element is emitted.
Further, in order to enable detection of the remaining amount of ink at a plurality of positions, a configuration in which the light emitting element and the light receiving element can be moved in the change direction of the liquid surface, and a plurality of sets of light emitting elements and light receiving elements are provided, Some proposals have been made in which these sets are arranged at different detection positions. However, all of these sets have a problem in that the configuration becomes large and the cost is disadvantageous.

  The present invention has been made in view of such circumstances, and an object thereof is a liquid storage member capable of detecting a liquid amount at a plurality of detection positions in the liquid storage member with a simple configuration, and a liquid consuming device. Is to provide.

The liquid storage member of the present invention has been proposed in order to achieve the above-described object, and includes a storage empty portion that stores liquid, and a liquid communication portion that communicates the storage empty portion with the outside.
A liquid storage member that is mounted on a liquid consumption device that consumes liquid and is configured to be able to communicate the liquid flow path on the liquid consumption device side and the storage space through the liquid communication portion,
It has an incident part on the upstream end side and an emission part on the downstream end side. Light from the light emitting element on the liquid consumption apparatus side is incident on the incident part, and is directed from the emission part to the light receiving element on the liquid consumption apparatus side. An optical waveguide that can be emitted,
The optical waveguide includes an incident waveguide that guides light incident substantially parallel to the axial direction from the incident portion to the downstream side, and an output waveguide that guides light from the incident waveguide side to the emission portion side. And having a plurality of detectors as inclined surfaces inclined with respect to the axial direction of the incident waveguide,
Each detection unit is disposed at a detection position having a different height in the storage unit, and in the immersion state immersed in the liquid, most of the light incident from the incident waveguide side is transmitted to the liquid side and immersed in the liquid. In a non-immersed state, it is provided in a state in which most of the incident light is reflected to the exit waveguide side as liquid amount detection light,
The present invention is characterized in that the amount of light emitted from the light emitting portion changes according to the immersion state or non-immersion state of each detection unit.
Note that the phrase “substantially parallel to the axial direction of the incident waveguide” includes a state slightly inclined with respect to the axial direction.

  According to the above configuration, the amount of light emitted from the emission unit changes between the immersion state and the non-immersion state of the plurality of detection units arranged at the detection positions with different heights in the storage empty portion. It becomes possible to detect the liquid amount of the storage member stepwise at a plurality of detection positions.

In the above configuration, the optical waveguide has an independent output waveguide for each of the detection units, and an output unit is provided for each of these output waveguides,
It is also possible to adopt a configuration in which each output waveguide guides the light reflected by the corresponding detection unit to the output unit side.

  Further, each of the detection units is configured such that at least a part of the light passing through the inside of the optical waveguide is smaller than the critical angle of total reflection at the boundary with the liquid, and the critical angle of total reflection at the boundary with air. It is desirable to be provided in a state where it is incident at a larger liquid amount detection angle.

In each of the above configurations, a configuration in which the liquid amount detection angle is set to about 45 ° can be employed.
Note that “approximately 45 °” means to include a state slightly deviated back and forth from 45 °.

  In each of the above-described configurations, it is desirable that the area of each detection unit excluding the detection unit at the lowest detection position is set to be narrower than the cross-sectional area in the direction orthogonal to the axis of the incident waveguide.

And in each said structure, it is desirable for the said optical waveguide to be comprised so that an internal light may let it pass in a single direction toward the said output part from the said incident part.
The term “single direction” means that the direction of the overall flow of light passing through the optical waveguide is single, and is used in the sense that the reflection direction in the middle is not considered.

  According to this configuration, since it is sufficient for the optical waveguide to be able to pass light in a single direction, for example, compared to the optical waveguide that transmits bidirectional light such as forward light and backward light, The cross-sectional area in the direction orthogonal to the axis can be reduced. As a result, the proportion of the volume of the optical waveguide in the storage space can be made as small as possible, and the degree of freedom of the shape of the optical waveguide can be ensured. Therefore, the present invention can be applied to a relatively small liquid storage member.

The liquid consuming apparatus of the present invention is equipped with the liquid storage member having the above-described configurations,
A light sensor that emits light to the incident portion; and a light sensor that has a light receiving element that receives light emitted from the light emitting portion; and A liquid amount detecting means for detecting the liquid amount is provided.

  According to the above configuration, since the configuration is such that the amount of light emitted from the emission unit changes between the immersion state and the non-immersion state of the plurality of detection units arranged at the detection positions with different heights in the storage space, With this configuration, the liquid amount of the liquid storage member can be detected at a plurality of detection positions.

  Furthermore, by applying the liquid storage member of the present invention to a liquid consuming apparatus provided with a liquid ejecting head capable of discharging liquid as liquid droplets, it is possible to detect a state in which the amount of liquid in the storage empty portion has become small. Since it is possible, the structure which notifies that to a user can also be taken. And according to this, the user can grasp | ascertain the more suitable replacement | exchange timing of a liquid storage member. Accordingly, it is possible to prevent problems such as damage to the liquid ejecting head due to the operation of the liquid ejecting head being continued in a state where the liquid is empty.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. In the following, as a type of liquid consuming device of the present invention, an ink jet recording head capable of ejecting ink in an ink cartridge corresponding to the liquid storage member of the present invention as ink droplets (a type of liquid ejecting head: An ink jet printer (hereinafter abbreviated as a printer) provided with a recording head) is taken as an example.

  FIG. 1 is a perspective view showing the configuration of the printer 1. The printer 1 has a recording head 2 attached thereto, a carriage 4 to which an ink cartridge 3 is detachably attached, a platen 5 disposed below the recording head 2, and the recording head 2 (carriage 4) as recording paper. 6 (a kind of ejected object), a carriage movement mechanism 7 that moves in the paper width direction, and a paper feed mechanism 8 that conveys the recording paper 6 in a paper feed direction that is a direction orthogonal to the head movement direction. ing. Here, the paper width direction is the main scanning direction, and the paper feeding direction is the sub-scanning direction.

The carriage 4 is attached while being supported by a guide rod 9 installed in the main scanning direction, and is configured to move in the main scanning direction along the guide rod 9 by the operation of the carriage moving mechanism 7. ing. The position of the carriage 4 in the main scanning direction is detected by the linear encoder 10, and a detection signal is transmitted as position information to the control unit 42 (see FIG. 3) of the printer controller. Thus, the control unit 42 can control the recording operation (ejection operation) by the recording head 2 while recognizing the scanning position of the carriage 4 (recording head 2) based on the position information from the linear encoder 10. .
Further, the carriage 4 is provided with an optical sensor 37 (see FIG. 3) used for detecting the remaining amount of ink in each ink cartridge 3 (corresponding to the amount of liquid in the present invention). The detection of the remaining amount of ink using the optical sensor 37 will be described later.

  FIG. 2 is a partial cross-sectional view illustrating the configuration of the recording head 2. The recording head 2 includes a case 12, a vibrator unit 13 housed in the case 12, a flow path unit 14 joined to the bottom surface (tip surface) of the case 12, and the like. The case 12 is made of, for example, an epoxy resin, and a housing empty portion 15 for housing the vibrator unit 13 is formed therein. The vibrator unit 13 includes a piezoelectric vibrator 16 that functions as a kind of pressure generating element, a fixing plate 17 to which the piezoelectric vibrator 16 is joined, and a flexible cable 18 for supplying a drive signal and the like to the piezoelectric vibrator 16. And. The piezoelectric vibrator 16 is a laminated type produced by cutting a piezoelectric plate in which piezoelectric layers and electrode layers are alternately laminated into a comb-like shape, and can extend and contract in a direction perpendicular to the lamination direction. This is a piezoelectric vibrator.

  The channel unit 14 is configured by joining a nozzle plate 20 to one surface of a channel forming substrate 19 and an elastic plate 21 to the other surface of the channel forming substrate 19. The flow path unit 14 is provided with a reservoir 22, an ink supply port 23, a pressure chamber 24, a nozzle communication port 25, and a nozzle opening 26. A series of ink flow paths from the ink supply port 23 to the nozzle opening 26 via the pressure chamber 24 and the nozzle communication port 25 are formed corresponding to each nozzle opening 26. An ink supply needle 62 (see FIG. 4) is connected to the reservoir 22 via an ink supply path 22 ′ (corresponding to a liquid flow path in the present invention).

  The nozzle plate 20 is a thin plate made of metal such as stainless steel in which a plurality of nozzle openings 26 are formed in a row at a pitch (for example, 180 dpi) corresponding to the dot formation density. The nozzle plate 20 is provided with a plurality of nozzle openings 26 (nozzle arrays), and one nozzle array is composed of, for example, 180 nozzle openings 26. The recording head 2 in the present embodiment has different colors of ink (one type of liquid in the present invention), specifically cyan (C), magenta (M), yellow (Y), and black (K). Four ink cartridges 3 storing a total of four colors of ink can be mounted, and a total of four nozzle rows are formed on the nozzle plate 20 corresponding to these colors. Details of the ink cartridge 3 will be described later.

  The elastic plate 21 has a double structure in which an elastic film 28 is laminated on the surface of a support plate 27. In the present embodiment, the elastic plate 21 is manufactured using a composite plate material in which a stainless plate, which is a kind of metal plate, is used as the support plate 27 and a resin film is laminated on the surface of the support plate 27 as an elastic film 28. The elastic plate 21 is provided with a diaphragm portion 29 that changes the volume of the pressure chamber 24. The elastic plate 21 is provided with a compliance portion 30 that seals a part of the reservoir 22.

  The diaphragm portion 29 is produced by partially removing the support plate 27 by etching or the like. That is, the diaphragm portion 29 includes an island portion 31 to which the distal end surface of the piezoelectric vibrator 16 is joined, and a thin elastic portion 32 surrounding the island portion 31. The compliance unit 30 is produced by removing the support plate 27 in the region facing the opening surface of the reservoir 22 by etching processing or the like in the same manner as the diaphragm unit 29, and reduces the pressure fluctuation of the liquid stored in the reservoir 22. Functions as a damper to absorb.

  Since the tip end surface of the piezoelectric vibrator 16 is joined to the island portion 31, the volume of the pressure chamber 24 can be changed by expanding and contracting the free end portion of the piezoelectric vibrator 16. As the volume changes, pressure fluctuations occur in the ink in the pressure chamber 24. The recording head 2 uses this pressure fluctuation to eject ink droplets from the nozzle openings 26.

  FIG. 3 is a block diagram showing an electrical configuration of the printer 1. The printer 1 is roughly composed of a printer controller 35, a print engine 36, and an optical sensor 37. The printer controller 35 includes an external interface (external I / F) 39 for receiving print data from an external device such as a host computer, a RAM 40 functioning as a work area for storing various data, and the like for various data processing. ROM 41 storing a control routine, a control unit 42 that controls each unit, an oscillation circuit 43 that generates a clock signal CK, a drive signal generation circuit 44 that generates a drive signal to be supplied to the recording head 2, and printing An internal interface (internal I / F) 45 for outputting ejection data, drive signals, and the like obtained by developing the data into a dot pattern to the recording head 2 is provided.

  The print engine 36 includes the recording head 2, a carriage moving mechanism 7, and a paper feeding mechanism 8. The recording head 2 has a shift register (SR) 49 in which ejection data is set, a latch circuit 50 that latches ejection data set in the shift register 49, a level shifter 51 that functions as a voltage amplifier, and the piezoelectric vibrator 16. A switch circuit 52 that controls the supply of drive signals and the piezoelectric vibrator 16 are provided.

  The optical sensor 37 includes a light emitting element 55 configured by a light emitting diode that emits diffused light and a light receiving element 56 configured by a photodiode or the like, and corresponds to four ink cartridges 3 in the present embodiment. Thus, a total of four sets of light emitting elements 55 and light receiving elements 56 are provided (light emitting elements 55a to 55d and light receiving elements 56a to 56d). The optical sensor 37 is electrically connected to the control unit 42, the light emission from the light emitting element 55 is controlled by the control unit 42, and according to the amount of light (the amount of received light) received by the light receiving element 56. A light reception signal is output to the control unit 42.

  Next, the ink cartridge 3 will be described. FIG. 4 is a cross-sectional view illustrating the configuration of the ink cartridge 3. The ink cartridge 3 in the present embodiment includes a hollow box-shaped case 59 in which an ink storage space (a kind of storage space in the present invention) 58 is formed, a lid member 60, and an ink storage space 58. An ink lead-out portion 61 (corresponding to a liquid communication portion in the present invention) that communicates with the outside of the ink cartridge 3 is configured. The case 59 is a box-shaped member whose upper surface is open, and the lid member 60 is a plate-shaped member that closes the open upper surface of the case 59. The case 59 and the lid member 60 are both members made of a synthetic resin such as polypropylene, and are integrated in a liquid-tight state by welding or adhesion. The ink lead-out portion 61 is formed at the bottom of the case 59 and is a portion into which the ink supply needle 62 provided on the recording head 2 side is inserted. In the ink lead-out portion 61, a packing 63 made of an elastic material such as an elastomer is disposed. Due to its elasticity, the packing 63 contacts the inserted ink supply needle 62 to ensure a liquid-tight state.

  A filter 64 that filters out foreign matter in the ink is disposed at the end of the ink outlet 61 on the ink storage space 58 side. For this reason, the ink in the ink reservoir 58 is led out to the ink supply needle 62 side after being filtered by the filter 64. When the ink supply needle 62 is inserted into the ink outlet 61, the ink reservoir 58 and the ink supply path 22 '(through the ink introduction hole (not shown) of the ink supply needle 62 and the needle flow path 62' are provided. 2) in a liquid-tight state, and ink is supplied to the reservoir 22 side of the recording head 2.

In the ink storage space 58 of the ink cartridge 3, for example, a prism portion 66 (corresponding to a kind of optical waveguide in the present invention) formed of a light transmissive member such as acrylic or glass is disposed. In the present embodiment, the prism portion 66 is made of a rod having a rectangular cross section made of polycarbonate. An incident portion 67 into which light from the light emitting element 55 is incident is formed, and the incident portion 67 extends in the axial direction. An incident waveguide 66a that guides light incident substantially in parallel to the downstream side and an output portion 68 capable of emitting light that has passed through the light receiving element 56 are formed, and the incident waveguide is provided on the output portion 68 side. An output waveguide 66b that guides light from the 66a side and a connecting waveguide 66c that connects these waveguides 66a and 66b in series are formed in a substantially U shape.
That is, the prism part 66 has an incident part 67 on the upstream end side and an emission part 68 on the downstream end side. Light from the light emitting element 55 enters from the incident part 67 and passes through the inside in a single direction. The light can be emitted from 68 toward the light receiving element 56.

The incident waveguide 66a includes a first incident waveguide 66a ′ and a second incident waveguide 66a ″. Between these incident waveguides 66a ′ and 66a ″, the first incident waveguide 66a ′. The first detection unit 70a as an inclined surface of 45 ° with respect to the axial direction of the first detection unit 70, and a surface parallel to the first detection unit 70a, the light from the first detection unit 70a side downstream (detection unit 70b A slope 69 having a first reflecting surface 71 that can be reflected is provided on the side), and the incident waveguides 66a ′ and 66a ″ are connected in a substantially crank shape by the slope 69.
Further, at the lower end of the second incident waveguide 66a ″, in other words, at the intersection of the second incident waveguide 66a ″ and the coupling waveguide 66c, the angle is 45 ° with respect to the axial direction of the second incident waveguide 66a ″. A second detection unit 70b formed as an inclined surface is provided, that is, in the middle of the prism unit 66, a plurality of detection units 70 used for detecting the remaining amount of ink are located at different positions (second detection unit 70b). Is provided at a position lower than the first detector 70a.

  A second reflecting surface 72 having an angle of 45 ° with respect to the axial direction of the waveguides 66b and 66c is formed at the intersection between the coupling waveguide 66c and the output waveguide 66b. The two reflection surfaces 72 are configured to be able to reflect light from the second detection unit 70b side toward the emission unit 68 side.

  With respect to the shape of the prism portion 66, it is sufficient that light can be passed through in a single direction. For example, the axis of the prism portion 66 can be compared with that in which bidirectional light such as forward light and backward light is allowed to pass. The cross-sectional area in the direction orthogonal to can be reduced. Thereby, the proportion of the volume of the prism portion 66 in the ink storage space 58 can be made as small as possible, and the degree of freedom of the shape of the prism portion 66 can be ensured. Therefore, the prism portion 66 can be applied to a relatively small liquid storage member such as the ink cartridge 3.

The first reflection surface 71 of the prism portion 66, the region A which is a projection region of the first reflection surface 71 and formed continuously to the detection portion 70b, and each surface of the second reflection surface 72 are provided on each surface. Mirror surface processing is performed by forming a metal film by vapor deposition or sputtering of a metal such as chromium or aluminum (the bold line portion in the figure). The thickness of the metal film is set to a thickness equal to or greater than the wavelength of light or infrared, specifically, a thickness of 1 μm or more, and the light incident on the mirror surface region is substantially totally reflected. Regarding this mirror processing, by further laminating a dielectric film such as SiO ₂ (silicon dioxide), Al ₂ O ₃ (alumina), ZrO ₂ (zirconia), Ta ₂ O ₅ (tantalum pentoxide) on the metal film, It is possible to form a mirror surface with less light loss than when only a metal film is used. Further, by forming the dielectric film as a protective film on the entire prism portion 66, the mirrored portion and the entire prism portion 66 are prevented from being eroded by the stored liquid, that is, the ink in the present embodiment. be able to.

  In the prism portion 66, the detection portions 70 a and 70 b are arranged at detection positions having different heights in the ink reservoir space 58, and the incident portion 67 and the emission portion 68 protrude outward (upward) from the lid member 60. The ink cartridge 3 is fixed in a state. The first detection unit 70a is arranged at a detection position that can detect a substantially central position in the liquid level change direction, that is, a state in which the remaining amount of ink in the ink storage empty portion 58 is about half, and the second detection unit 70a. 70b is arranged at a detection position where the lower side in the liquid level change direction (near the bottom of the ink cartridge 3), that is, the state where the remaining amount of ink in the ink storage space 58 is small (near end) can be detected. Yes.

  In a state where the ink cartridge 3 is properly mounted at an appropriate position of the printer 1 (carriage 4), the incident portion 67 and the emission portion 68 are opposed to the light emitting element 55 and the light receiving element 56 of the optical sensor 37, respectively. Yes. The incident portion 67 is a plane orthogonal to the axial direction of the incident waveguide 66a, and is configured such that light from the light emitting element 67 is incident substantially perpendicularly. That is, the light emitted from the light emitting element 55 enters the prism portion 66 (in the first incident waveguide 66a ′) substantially parallel to the axial direction of the incident waveguide 66a.

  In the present embodiment, the area of the detection unit 70 excluding the second detection unit 70b arranged at the lowest detection position, that is, the direction in which the area of the first detection unit 70a is orthogonal to the axis of the incident waveguide 66a. It is set narrower than the cross-sectional area. Therefore, a part of the light from the incident part 67 side enters the first detection part 70a at an incident angle of about 45 °, and the rest passes through the gap between the first detection part 70a and the first reflection surface 71, and passes through the second. The light is incident on the second detection unit 70b provided at the downstream end of the incident waveguide 66a "at an incident angle of about 45 °. Further, the surface including the second detection unit 70b and the mirror surface region A is The area where most of the light from the upstream side can enter is set, and the light (liquid level detection light) reflected by the first detection unit 70a is reflected by the first reflecting surface 71, 2 Reflected downstream in the mirror surface area A adjacent to the detector 70b.

  Here, with respect to the light emitted from the light emitting element 55 in the present embodiment, the refractive index of polycarbonate, which is the material of the prism portion 66, is about 1.59, and the refractive index of the water-based ink is about 1.33. Therefore, the detection unit in a state where the position of the ink liquid surface is above the detection position of the detection unit 70 (on the lid member 60 side) and the detection unit 70 is immersed in ink (hereinafter referred to as an immersion state). The critical angle of total reflection at the boundary between 70 and ink is approximately 57 °. On the other hand, in a state where the ink liquid level is below the detection position of the detection unit 70 (on the bottom side of the ink cartridge 3) and the detection unit 70 is in contact with air (hereinafter referred to as a non-immersion state). The critical angle of total reflection at the boundary between the detector 70 and air (refractive index 1) is approximately 39 °. That is, each detection unit 70 is an angle smaller than the critical angle at the boundary with the ink and larger than the critical angle of the total reflection angle at the boundary with the air (hereinafter referred to as a liquid amount detection angle θd). Light from the incident portion 67 is made incident. Therefore, most of the light incident on each detection unit 70 is transmitted to the ink side (ink storage space 58 side) in the immersed state, but most of the light is reflected downstream as liquid amount detection light in the non-immersed state. It is like that.

  Note that the detection unit 70 in this embodiment is subjected to a water repellent treatment by applying a water repellent material, thereby allowing ink droplets to adhere in a non-immersed state that is not immersed in ink. As a result, it is possible to prevent the detection accuracy from being lowered due to light scattering at the portion where the ink droplets are attached. A fluorine-based coating material can be used as the water repellent material. Note that this water repellent treatment may be applied to the entire prism portion 66.

  In the prism unit 66 configured as described above, the amount of light emitted from the emission unit 68 changes stepwise according to the immersion state or non-immersion state of each detection unit 70. In other words, the amount of light emitted from the light emitting portion 68 changes stepwise in accordance with the position of the ink level in the ink storage space 58. In the printer 1 configured as described above, the prism unit 66, the control unit 42, and the optical sensor 37 function as the liquid amount detection means in the present invention, and the change in the amount of light emitted from the emission unit 68, that is, the amount of light received by the light receiving element 56. Based on the change in the (light reception signal), the remaining amount of ink in the ink storage space 58 is detected.

  Hereinafter, detection of the remaining amount of ink will be described with reference to FIGS. FIG. 4 shows a state in which the ink in the ink storage empty portion 58 is full (the immersion state of the detection units 70a and 70b). FIG. 5 shows a state in which the ink level is below the detection position of the first detection unit 70a and the ink remaining amount is substantially halved (the non-immersion state of the first detection unit 70a and the second detection unit 70b). FIG. 6 shows a state in which the ink level is below the detection position of the second detection unit 70b and the ink remaining amount is slightly (near end) (the detection units 70a and 70b are not immersed). State).

  In the state of FIG. 4, part of the light emitted from the light emitting element 55 and incident into the prism part 66 in parallel to the axial direction of the incident waveguide 66 a from the incident part 67 is directed to the first detection part 70 a, and the rest The light enters the second detection unit 70b at the liquid amount detection angle θd. In the state shown in FIG. 4, both of the detection units 70 a and 70 b are in an immersed state, and most of the light incident on each detection unit 70 is transmitted to the ink side (ink storage space 58 side). Therefore, in the state shown in FIG.

  Light emitted from the light emitting portion 68 is received by the light receiving element 56, and a light receiving signal having a level corresponding to the amount of light received is output to the light receiving element 56 control unit 42. In the present embodiment, the storage means such as the ROM 41 stores a table indicating the relationship between the amount of light emitted from the light emitting portion 68, that is, the level of the light receiving signal of the light receiving element 56 and the ink remaining amount. Referring to this table, the remaining amount of ink corresponding to the level of the received light signal is determined (detected). The control unit 42 determines that the remaining amount of ink in the ink reservoir 58 is sufficient (more than half) at the level of the light reception signal in the state of FIG.

  Next, in the state of FIG. 5, since the ink level in the ink reservoir 58 is located between the first detector 70a and the second detector 70b, the first detector 70a is not in use. It is in an immersion state, and the second detection unit 70b is in an immersion state. For this reason, most of the light incident on the first detection unit 70a is reflected on the downstream side (first reflection surface 71 side) as liquid amount detection light, while most of the light incident on the second detection unit 70b is on the ink side. To penetrate.

  The light reflected as the liquid amount detection light in the first detection unit 70a is reflected by the first reflection surface 71 toward the second detection unit 70b. The light reflected by the first reflecting surface 71 is reflected downstream by the mirror region A through the second incident waveguide 66a ″, and further reflected by the second reflecting surface 72 through the connecting waveguide 66c. The light reflected by the two reflecting surfaces 72 passes through the output waveguide 66b and is output from the output unit 68 and received by the light receiving element 56. Therefore, in the state shown in FIG. The amount of light emitted from the section 68 increases, and a light reception signal corresponding to this is output from the light receiving element 56 to the control section 42. Then, the control section 42 in the ink reservoir 58 according to the level of this light reception signal. It is determined that the remaining amount of ink is approximately half.

  In the state of FIG. 6, that is, in a state where the remaining amount of ink in the ink storage chamber 58 is small and the ink level is below the detection position of the second detection unit 70 b, both the detection units 70 a and 70 b. Becomes a non-immersed state. Therefore, most of the light incident on these detection units 70 a and 70 b is reflected downstream as liquid amount detection light and is emitted from the emission unit 68. As a result, the amount of light emitted from the emitting portion 68 is further increased and maximized as compared with the state of FIG. 5, and a light receiving signal at a level corresponding to the amount of received light is output from the light receiving element 56 to the control portion 42. When the light reception signal from the light receiving element 56 exceeds the level corresponding to the near end based on the above table, the control unit 42 determines that the remaining amount of ink in the ink storage chamber 58 has become the near end. That is, a state where the ink remaining amount is near-end is detected.

  When the control unit 42 detects the remaining amount of ink in the ink storage chamber 58 as described above, the control unit 42 performs processing for notifying the user of the remaining amount of ink in the ink cartridge 3. For example, the control unit 42 outputs information indicating the remaining ink amount to an external device such as a host computer via the external I / F 39. In response to this, the external device can display the remaining amount of ink in each ink cartridge 3 on the display device based on the information on the remaining amount of ink. For example, a bar whose length changes according to the remaining amount of ink can be displayed so that the user can easily visually recognize the remaining amount of ink in the ink cartridge 3, or printing with the remaining ink is possible The number of images can be displayed.

  In addition, when the ink remaining amount becomes near end, the control unit 42 displays a lamp indicating that the near end has been displayed on a display device provided on the outer surface of the housing of the printer 1 or a display device of an external device. By performing control of lighting or blinking (not shown) or the like, the user is notified that the remaining amount of ink in the ink cartridge 3 has become small. As a result, the user can grasp the more appropriate replacement timing of the ink cartridge 3, so that the ink can be used without waste, and the running cost burden on the user can be reduced. Further, it is possible to prevent problems such as damage to the recording head 2 caused by continuing the recording operation in a state where the ink in the ink cartridge 3 is empty.

  As described above, the amount of light emitted from the light emitting portion 68 is stepwise in the immersion state and the non-immersion state of the plurality of detection portions 70 in which the prism portion 66 is disposed at the detection positions at different heights in the ink reservoir space 58. Since it is configured to change, it is possible to detect the remaining ink amount (liquid amount) of the ink cartridge 3 at a plurality of detection positions with a simple configuration.

  In this embodiment, the case where the remaining amount of ink is detected at two detection positions using the two detection units 70, that is, the first detection unit 70a and the second detection unit 70b, is illustrated. However, by providing three or more detection units 70 and disposing these detection units 70 at detection positions with different heights in the ink storage space 58, the remaining ink level at more detection positions. Detection is possible.

  Further, the surface of the prism part 66 excluding the incident part 67, the detection part 70, and the emission part 68 may be mirror-finished. According to this configuration, unnecessary leakage of light at portions other than the detection unit 70 can be prevented, so that detection accuracy can be improved.

  Further, by performing semi-mirror surface processing on all the detection units 70 so that light is always emitted from the emission unit 68 regardless of the non-immersed state or the non-immersed state, the mounted state of the ink cartridge 3 can be achieved. Appropriateness and the operating state of the optical sensor 37 can be detected. For example, in a state in which outgoing light is obtained from the light emitting unit 68, that is, in a state in which a light reception signal is output from the light receiving element 56, the control unit 42 determines whether the ink cartridge 3 is mounted or the optical sensor 37 is operating. Judge that it is normal. On the other hand, when the positions of the incident part 67 and the emission part 68 with respect to the light emitting element 55 and the light receiving element 56 are shifted, or when a malfunction such as the optical sensor 37 not operating due to a lifetime or failure occurs, the emission part. No light is emitted from 68, and no light reception signal is output from the light receiving element 56. In this case, the control unit 42 determines that the mounting state of the ink cartridge 3 and the operation state of the optical sensor 37 are abnormal. The control unit 42 performs a process of notifying the user that the ink cartridge 3 or the optical sensor 37 is in an abnormal state, so that the user can confirm the mounting state of the ink cartridge 3 or the optical sensor 37. Measures such as replacement of the light emitting element 55 or the light receiving element 56 can be performed.

Next, a second embodiment of the present invention will be described.
FIG. 7 is a cross-sectional view illustrating the configuration of the ink cartridge 3 in the second embodiment. In addition, the same code | symbol is attached | subjected to the part same as the said 1st Embodiment, The description is abbreviate | omitted suitably. The prism portion 75 in this embodiment is characterized in that a branched waveguide is provided between the first incident waveguide 66a ′ and the second incident waveguide 66a ″. The second coupling waveguide 66c ′ that intersects the incident waveguide 66a ′ at a right angle and guides the light reflected as the liquid quantity detection light by the first detection unit 70a, and the second coupling waveguide 66c ′ is bent upward by 90 °. A second output waveguide 66b 'is provided, and a second output portion 68' is formed in the second output waveguide 66b'.The second connection waveguide 66c 'and the second output guide are formed. A third reflecting surface 72 ′ having an angle of 45 ° with respect to the axial direction of the waveguides 66 b ′ and 66 c ′ is formed at the intersection with the waveguide 66 b ′. The third reflecting surface 72 ′ is formed. The light from the first detection unit 70a side is directed to the second emission unit 68 ′ side. It is configured to be reflective.

  That is, the prism portion 75 in the present embodiment has independent output waveguides 66b and 66b ′ for each of the detection portions 70a and 70b, and the output portions 68 and 68 ′ for each of these output waveguides 66b and 66b ′. Each of the output waveguides 66b and 66b ′ guides the light reflected as the liquid amount detection light by the corresponding detection units 70a and 70b to the output units 68 and 68 ′, respectively. The optical sensor 37 is provided with a second light receiving element 56 'corresponding to the second emitting portion 68'.

  Accordingly, the amount of light emitted from the emission units 56 and 56 'varies independently depending on whether the detection units 70a and 70b are immersed or not. That is, when the ink level is above the detection position of the first detection unit 70a, the light incident on each detection unit 70 is transmitted to the ink side. Although both are slight, when the ink liquid level is located between the first detection unit 70a and the second detection unit 70b, most of the light incident on the first detection unit 70a is liquid amount detection light. Since most of the light incident on the second detection unit 70b is transmitted to the ink side while being reflected to the downstream side (the second output waveguide 66b ′ side), only the amount of light emitted from the second output unit 68 ′ is abrupt. To increase. When the ink level falls below the detection position of the second detection unit 70b, the light incident on the second detection unit 70b is also downstream as the liquid amount detection light. Increases rapidly.

  Therefore, when only the amount of light emitted from the second light emitting portion 68 'increases, that is, when only the level of the light reception signal of the second light receiving element 56' increases rapidly, the control unit 42 determines that the ink reservoir 58 In the case where it is determined that the remaining amount of ink is substantially halved and the amount of light emitted from the light emitting portion 68 is further increased, that is, when the level of the light receiving signal of the light receiving element 56 is rapidly increased, the ink reservoir empty space 58 It is determined that the remaining amount of ink is near-end.

By the way, the present invention is not limited to the above-described embodiments, and various modifications can be made based on the description of the scope of claims.
For example, with respect to the liquid amount detection angle θd, in the above-described embodiment, an example in which the liquid amount detection angle is set to 45 ° has been described. However, the present invention is not limited to this. Any angle can be adopted as long as it is larger than the critical angle of the total reflection angle at the boundary with air.

  Moreover, in each said embodiment, although the ink cartridge 3 was illustrated as a liquid storage member in which the liquid in a storage empty part reduces, it is not restricted to this. For example, the present invention is also applied to a liquid storage member in which the liquid in the storage empty space increases, such as a waste ink tank that stores waste ink generated by a cleaning operation or a flushing operation (ink droplet discarding) in a printer. Is also possible. In this case, it is also possible to detect the state in which the light emitted from the emission unit is no longer obtained as a state immediately before the full amount by disposing the detection unit at the detection position corresponding to the liquid in the storage empty portion immediately before the full amount.

  Regarding the optical sensor 37, in the above description, an example in which four sets of the light emitting element 55 and the light receiving element 56 (56 ′) are provided corresponding to the four ink cartridges 3 is shown, but the present invention is not limited thereto. For example, only one set of the light emitting element 55 and the light receiving element 56 (56 ′) is provided, and the incident portion 67 and the emitting portion 68 (68 ′) of the ink cartridge 3 to be detected are respectively the light emitting element 55 and the light receiving element 56 (56 ′). Alternatively, the carriage 4 may be configured to move so as to face the surface.

  Regarding the shape of the prism part 66 (prism part 75), it is not restricted to what was illustrated in said each embodiment. For example, like a prism portion 76 shown in FIG. 8, a rod having a circular cross section is formed in a substantially U shape, and a relatively gentle bent portion 77 is formed on the incident waveguide 66a (or the output waveguide 66b). A plurality of them may be provided. The bent portion 77 is formed by bending the incident waveguide 66a at an angle of 45 ° or less with respect to its axial direction. By configuring the prism portion 76 in this way, the light incident from the incident portion 67 is reflected by the bent portion 77 and the like, and a component incident on the wall surface of the prism portion 76 at the liquid surface incident angle θd can be generated. . Therefore, also by this modification, the liquid amount can be detected at a plurality of locations as in the above embodiments.

  In the above embodiment, the so-called longitudinal vibration mode piezoelectric vibrator 16 is exemplified as the pressure generating element of the present invention, but the present invention is not limited to this. For example, a piezoelectric vibrator that can vibrate in the electric field direction (the stacking direction of the piezoelectric body and the internal electrode) may be used. In addition, the nozzles are not limited to being unitized, but may be provided for each pressure chamber 24 as in a so-called flexural vibration mode piezoelectric vibrator. Further, not only the piezoelectric vibrator but also other pressure generating elements such as a heating element can be used.

  The present invention can also be applied to a liquid consuming device other than the printer as long as it is equipped with a liquid storage member that stores liquid. For example, it can be applied to a display manufacturing apparatus, an electrode manufacturing apparatus, a chip manufacturing apparatus, a micropipette, and the like.

FIG. 2 is a perspective view illustrating a configuration of a printer. FIG. 3 is a cross-sectional view of a main part illustrating the configuration of a recording head. 2 is a block diagram illustrating an electrical configuration of a printer. FIG. FIG. 5 is a cross-sectional view illustrating the configuration of the ink cartridge, and is a diagram illustrating a state where the ink in the ink storage space is full. FIG. 4 is a cross-sectional view illustrating the configuration of the ink cartridge, and is a diagram illustrating a state in which the remaining amount of ink in the ink storage space is substantially halved. FIG. 5 is a cross-sectional view illustrating the configuration of the ink cartridge, and is a diagram illustrating a state in which the remaining amount of ink in the ink storage space is near end. It is sectional drawing explaining the structure of the ink cartridge in 2nd Embodiment. It is an enlarged view explaining the modification of a prism part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer, 2 Recording head, 3 Ink cartridge, 4 Carriage, 5 Platen, 6 Recording paper, 7 Carriage moving mechanism, 8 Paper feed mechanism, 9 Guide rod, 10 Linear encoder, 12 Case, 13 Vibrator unit, 14 Flow path Unit, 15 Storage space, 16 Piezoelectric vibrator, 17 Fixed plate, 18 Flexible cable, 19 Flow path forming substrate, 20 Nozzle plate, 21 Elastic plate, 22 Reservoir, 22 'Ink flow path, 23 Ink supply port, 24 Pressure Chamber, 25 Nozzle communication port, 26 Nozzle opening, 27 Support plate, 28 Elastic membrane, 29 Diaphragm part, 30 Compliance part, 31 Island part, 32 Thin elastic part, 35 Printer controller, 36 Print engine, 37 Light sensor, 39 External interface, 40 RAM, 41 ROM, 42 control unit, 3 Oscillation circuit, 44 Drive signal generation circuit, 45 Internal interface, 47 Paper feed motor, 49 Shift register, 50 Latch circuit, 51 Level shifter, 52 Switch circuit, 55 Light emitting element, 56 Light receiving element, 58 Ink storage space, 59 Case , 60 Lid member, 61 Ink lead-out part, 62 Ink supply needle, 63 Packing, 64 Filter, 66 Prism part, 67 Incidence part, 68 Emission part, 69 Inclination part, 70 Detection part, 71, 72 Reflecting surface, 75 Prism part

Claims (8)

A storage space for storing liquid, and a liquid communication portion for communicating the storage space with the outside,
A liquid storage member that is mounted on a liquid consumption device that consumes liquid and is configured to be able to communicate the liquid flow path on the liquid consumption device side and the storage space through the liquid communication portion,
It has an incident part on the upstream end side and an emission part on the downstream end side. Light from the light emitting element on the liquid consumption apparatus side is incident on the incident part, and is directed from the emission part to the light receiving element on the liquid consumption apparatus side. An optical waveguide that can be emitted,
The optical waveguide includes an incident waveguide that guides light incident substantially parallel to the axial direction from the incident portion to the downstream side, and an output waveguide that guides light from the incident waveguide side to the emission portion side. And having a plurality of detectors as inclined surfaces inclined with respect to the axial direction of the incident waveguide,
Each detection unit is disposed at a detection position having a different height in the storage unit, and in the immersion state immersed in the liquid, most of the light incident from the incident waveguide side is transmitted to the liquid side and immersed in the liquid. In a non-immersed state, it is provided in a state in which most of the incident light is reflected to the exit waveguide side as liquid amount detection light,
A liquid storage member configured to change the amount of light emitted from the light emitting portion according to an immersion state or a non-immersion state of each detection unit. The optical waveguide has an independent output waveguide for each detection unit, and an output unit is provided for each of these output waveguides,
The liquid storage member according to claim 1, wherein each of the output waveguides guides the light reflected by the corresponding detection unit to the output unit side.   In each of the detection units, at least a part of the light passing through the inside of the optical waveguide is smaller than the critical angle of total reflection at the boundary with the liquid, and more than the critical angle of total reflection at the boundary with air. 3. The liquid storage member according to claim 1, wherein the liquid storage member is provided so as to be incident at a larger liquid amount detection angle.   The liquid storage member according to claim 3, wherein the liquid amount detection angle is set to approximately 45 °.   The area of each detection part except the detection part of the lowest detection position is set narrower than the cross-sectional area in the direction orthogonal to the axis of the incident waveguide. The liquid storage member according to any one of the above.   The liquid storage member according to any one of claims 1 to 5, wherein the optical waveguide passes light in a single direction from the incident part toward the emission part. The liquid storage member according to any one of claims 1 to 6 is mounted,
A light sensor that emits light to the incident portion; and a light sensor that has a light receiving element that receives light emitted from the light emitting portion; and A liquid consumption apparatus comprising a liquid amount detection means for detecting a liquid amount.   The liquid consuming apparatus according to claim 7, further comprising a liquid ejecting head capable of ejecting liquid as droplets.

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