JP2018058263A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer having a high degree of freedom of arrangement positions of ink tanks and being capable of accurately determining a liquid level reduction of ink.SOLUTION: A printer 110 comprises: a plurality of ink tanks 10 being disposed in a predetermined direction and storing ink IK; prisms 24 disposed for each ink tank 10 on surfaces of the same side of a direction intersecting with the predetermined direction in the ink tanks 10; detection substrates 25 disposed so as to face the prisms 24; detection sections 23 being disposed for each ink tank 10 on surfaces of sides facing the prisms 24 of the detection substrates 25, and having light emission sections 26a applying light and light reception sections 26b outputting detection signals according to received light amounts of reflected light; control sections 40 causing the light emission sections 26a to apply the light, and determining whether or not the ink IK exists at predetermined positions in the ink tanks 10 based on the detection signals output from the light receiving sections 26b; and a carriage 20 disposed with a print head 22 injecting the ink IK.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a printing apparatus.

  As an example of a printing apparatus, an ink jet printer (hereinafter simply referred to as a printer) is known. In a printer, ink, which is an example of liquid, is stored in an ink cartridge or an ink tank, which is an example of a liquid container, and printing can be performed by ejecting ink from a print head onto a print medium such as print paper. . In such a printer, if ink is consumed and there is no ink to be ejected, the printer becomes idle. In order to avoid this, a printer that detects the remaining amount of ink with an optical sensor has been proposed (see, for example, Patent Document 1).

  In the printer described in Patent Document 1, an optical sensor is arranged on a carriage on which a print head is arranged. The ink cartridges are arranged so as to be aligned along the carriage moving direction. Each ink cartridge is provided with a light-transmitting prism-like reflecting member at a position facing an optical sensor that moves with the carriage in the carriage movement path. The optical sensor moves to a position facing the reflecting member, emits light from the light emitting element of the optical sensor, and ink in the ink cartridge is based on the detection value of the reflected light from the reflecting member received by the light receiving element of the optical sensor. The remaining amount of is detected.

JP 2004-1480 A

  However, in the printer described in Patent Document 1, when detecting the remaining amount of ink in the ink cartridge, the optical sensor arranged on the carriage is moved with respect to the plurality of ink cartridges. Therefore, unless the ink cartridges are arranged in a line along the carriage movement direction, the optical sensor cannot be opposed to the reflecting member of each ink cartridge. Accordingly, the arrangement direction of the ink cartridge is limited to the carriage movement direction. In other words, there is a problem that the arrangement position of the ink cartridge is limited in the device design of the printer.

  Further, when detecting the remaining amount of ink in the ink cartridge, the relative positional relationship between the reflecting member of each ink cartridge and the optical sensor changes. Therefore, there is a problem that the reflected light received by the light receiving element of the optical sensor includes reflected light (noise component) other than the reflected light that should be received, and the detection accuracy may be lowered.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A printing apparatus according to this application example includes a plurality of liquid containers that are arranged along a predetermined direction and that store liquids on the same side in a direction that intersects the predetermined direction of the liquid containers. A reflection portion disposed on each surface of the liquid container; a detection substrate disposed to face the reflection portion of the liquid container; and the liquid on a surface of the detection substrate facing the reflection portion. A light-emitting unit that emits light, and a light-receiving unit that outputs a detection signal according to the amount of reflected light of the light emitted from the light-emitting unit, the light-emitting unit disposed for each container; A controller for irradiating the light with the light, and determining whether the liquid is present at a predetermined position in the liquid container based on the detection signal output from the light receiving unit; and printing for ejecting the liquid And a carriage on which the head is arranged. To.

  According to the configuration of the printing apparatus of this application example, the light emission of the detection unit is performed so as to face the reflection unit disposed for each liquid container on the same side surface of the plurality of liquid containers disposed along the predetermined direction. And a light receiving portion are arranged for each liquid container. That is, when the control unit determines whether or not the liquid is present at a predetermined position in the liquid container, it is not necessary to move the carriage, and the reflection unit, the light emitting unit, and the light receiving unit of each liquid container face each other. The positional relationship does not change. Accordingly, the arrangement position of the liquid container in the apparatus design of the printing apparatus can be determined without being restricted by the movement direction of the carriage. In addition, when determining whether or not there is a liquid at a predetermined position, the influence of reflected light (noise component) that occurs when the relative positional relationship between the reflective portion of the liquid container, the light emitting portion, and the light receiving portion changes. Can be suppressed. Therefore, it can be accurately determined whether or not there is a liquid at a predetermined position in the liquid container.

  Application Example 2 In the printing apparatus according to the application example described above, the detection unit further includes a selection circuit disposed on the detection substrate, and the control unit includes one of the plurality of liquid containers. A selection signal for selecting the detection unit of the liquid container is transmitted to the selection circuit, and the selection circuit receives the detection signal from the light receiving unit of the selected detection unit based on the selection signal. It is preferable to transmit to the control unit.

  According to the configuration of the application example, for a liquid container selected based on a selection signal from the control unit among the plurality of liquid containers, the selection circuit arranged on the detection substrate of the detection unit outputs the detection signal from the light receiving unit. Send to the control unit. Therefore, the number of input / output ports for connecting the control unit and the detection board and the number of signal lines for electrically connecting the control unit and the detection board can be reduced as compared with the case where the selection circuit is not provided. .

  Application Example 3 In the printing apparatus according to the application example described above, it is preferable that the liquid container includes a replenishing port through which a user can replenish the liquid.

  According to the configuration of this application example, since the refill port is provided in the liquid container, the user can refill the liquid container from the refill port when the remaining amount of the liquid in the liquid container decreases.

  Application Example 4 In the printing apparatus according to the application example described above, it is preferable that the main scanning direction of the carriage is a direction that intersects the predetermined direction.

  According to the configuration of this application example, since the main scanning direction of the carriage intersects the predetermined direction, a plurality of liquid containers can be arranged without being restricted by the main scanning direction of the carriage. Further, by arranging the plurality of liquid containers so as to be aligned in a direction intersecting with the main scanning direction of the carriage, the liquid containers are arranged along the main scanning direction of the carriage as compared with the case where they are aligned in parallel with the main scanning direction of the carriage. It is possible to reduce the length of the printing apparatus in the selected direction.

  Application Example 5 In the printing apparatus according to the application example, it is preferable that the reflection unit is a prism disposed on the detection unit side in the liquid container.

  According to the configuration of this application example, when the liquid in the liquid container is present at a position where the light emitted from the light emitting unit is incident on the prism, the light emitted from the light emitting unit is refracted at the interface between the prism and the liquid. Then proceed in the liquid. On the other hand, if the liquid in the liquid container does not exist at the position where the light emitted from the light emitting part is incident on the prism, the light emitted from the light emitting part is reflected by the interface between the prism and air and received by the light receiving part. Is done. Therefore, it can be determined whether or not there is liquid at a predetermined position in the liquid container based on the amount of light received by the light receiving unit.

  Application Example 6 In the printing apparatus according to the application example, the reflection unit is a reflection plate facing the detection unit via the liquid when the liquid container is filled with the liquid. Preferably there is.

  According to the configuration of this application example, when the liquid in the liquid container is present at a position where the light emitted from the light emitting unit enters the liquid container, the liquid is interposed between the detection unit and the reflection plate. The light emitted from the light emitting part attenuates in the liquid. On the other hand, the liquid in the liquid container is irradiated from the light emitting unit because the liquid does not intervene between the detection unit and the reflecting plate when the light irradiated from the light emitting unit is not present at the position where the light enters the liquid container. The reflected light is reflected by the reflecting plate and received by the light receiving unit. Therefore, it can be determined whether or not there is liquid at a predetermined position in the liquid container based on the amount of light received by the light receiving unit.

1 is a perspective view illustrating a basic configuration of a printer system according to a first embodiment. 1 is a schematic configuration diagram of a printer according to a first embodiment. FIG. 3 is a perspective view illustrating a schematic configuration of an ink supply unit according to the first embodiment. FIG. 3 is a cross-sectional view of the ink tank according to the first embodiment. FIG. 3 is a cross-sectional view of the ink tank according to the first embodiment. The figure which shows the electrical structure of the detection part which concerns on 1st Embodiment. FIG. 3 is a cross-sectional view of the ink tank according to the first embodiment. FIG. 3 is a cross-sectional view of the ink tank according to the first embodiment. Sectional drawing of the ink tank which concerns on 2nd Embodiment. Sectional drawing of the ink tank which concerns on 2nd Embodiment. Sectional drawing of the ink tank which concerns on 2nd Embodiment. Sectional drawing of the ink tank which concerns on 2nd Embodiment.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. The drawings to be used are appropriately enlarged, reduced or exaggerated so that the part to be described can be recognized. In addition, illustrations of components other than those necessary for the description may be omitted.

(First embodiment)
<Basic configuration of printer system>
A basic configuration of a printer system including an inkjet printer (hereinafter simply referred to as a printer) as a printing apparatus according to the first embodiment will be described with reference to FIG. FIG. 1 is a perspective view illustrating a basic configuration of the printer system according to the first embodiment. The printer system 100 according to the first embodiment is a multifunction machine including a printer 110 as a printing apparatus and a scanner 120.

  FIG. 1 shows a Y axis, an X axis orthogonal to the Y axis, and a Z axis orthogonal to the X axis and the Y axis. In each of the XYZ axes, the direction of the arrow indicates the + direction (positive direction), and the direction opposite to the direction of the arrow indicates the − direction (negative direction). In the use state, the printer system 100 is arranged on a horizontal plane defined by the X axis and the Y axis, and the + Y direction is the front of the printer system 100. The Z axis is an axis orthogonal to a horizontal plane, and the −Z direction is a vertically downward direction.

  As shown in FIG. 1, the printer system 100 includes a printer 110, a scanner 120, and an ink supply unit 1. The printer system 100 has an operation panel 111 as a user interface unit on the front side.

  On the operation panel 111, for example, buttons for performing operations such as power ON / OFF of the printer system 100, printing by the printer 110, reading of an original by the scanner 120, operation states and messages of the printer system 100, and the like are displayed. A display unit 47 for displaying is arranged. The operation panel 111 is also provided with a reset button that is pressed when the user refills the ink tank 10 with ink.

  The printer 110 can print on a printing medium P such as printing paper by ejecting ink as a liquid. The printer 110 has a case unit 112. The case part 112 constitutes the outer shell of the printer 110. An opening 113 is provided on the front side of the case portion 112. A paper cassette 114 is detachably attached to the case portion 112 in the opening 113. Above the paper cassette 114 (+ Z direction), a paper discharge tray 115 is provided to be extendable in the front-rear direction (+ Y direction and −Y direction).

  Although details will be described later, the X-axis direction (+ X direction and −X direction) is the main scanning direction HD of the print head 22 (see FIG. 2) of the printer 110, that is, the movement direction of the carriage 20 (see FIG. 2). The Y-axis direction (+ Y direction and −Y direction) is the sub-scanning direction VD of the printer 110. A plurality of print media P are stacked on the paper cassette 114. The print medium P placed on the paper cassette 114 is supplied to the inside of the case unit 112 one by one along the sub-scanning direction VD, printed by the printer 110, and then discharged along the sub-scanning direction VD. The paper is discharged from 116 and placed on a paper discharge tray 115.

  The scanner 120 is placed on the printer 110. The scanner 120 has a case unit 121. The case part 121 constitutes the outer shell of the scanner 120. The scanner 120 is a flat bed type, and includes a document table (not shown) formed of a transparent plate member such as glass, and an image sensor (not shown) such as an image sensor. The scanner 120 can read an image or the like recorded on a medium such as paper as image data via an image sensor.

  The scanner 120 includes an auto document feeder 122 at the upper end. The auto document feeder 122 can sequentially feed and read a plurality of stacked originals (sheets on which images and the like are recorded) one by one. The scanner 120 is configured to be rotatable with respect to the printer 110 and also has a function as a lid of the printer 110. The user can rotate the scanner 120 with respect to the printer 110 by inserting a finger into the handle portion 123 and lifting the scanner 120 upward. Thereby, the scanner 120 can be opened with respect to the printer 110.

  The ink supply unit 1 is disposed on the side of the printer 110 in the + X axis direction. The ink supply unit 1 has a function of supplying ink IK (see FIG. 5) as a liquid to the printer 110. The ink supply unit 1 has a case unit 101. A plurality of ink tanks 10 as a plurality of liquid containers are arranged in the case portion 101, and a plurality of different types of ink IK are individually stored in the plurality of ink tanks 10. That is, different types of ink IK are stored in the plurality of ink tanks 10 for each ink tank 10.

  In the present embodiment, four ink tanks 10 (10a, 10b, 10c, 10d) are provided. In the present embodiment, four types of ink, black ink and color (yellow, magenta, and cyan) ink, are employed. The ink tank 10a contains black ink IK, and the ink tanks 10b, 10c, 10d contain color (yellow, magenta, cyan) ink IK.

  The ink tanks 10 a, 10 b, 10 c, and 10 d are arranged so as to be aligned along a direction that intersects the main scanning direction HD (X-axis direction), and are fixed in the case portion 101. In the present embodiment, the ink tanks 10a, 10b, 10c, and 10d are arranged so as to be aligned along a predetermined direction (Y-axis direction) from the front side of the printer 110. Hereinafter, when the four ink tanks 10a, 10b, 10c, and 10d are not distinguished, they are simply referred to as the ink tank 10.

  In the present embodiment, each of the four ink tanks 10 is configured to be able to inject ink IK into the ink tank 10 from the outside of the printer system 100. Therefore, the user of the printer system 100 can refill the ink tank 10 with the ink IK stored in another container. The detailed configuration of the ink tank 10 will be described later.

  The case portion 101 is provided with a window portion 102 corresponding to each of the four ink tanks 10. The window part 102 has optical transparency. Therefore, the user can visually recognize the four ink tanks 10 through the window portion 102. The window part 102 may be provided as an opening part formed in the case part 101, and may be comprised with the member which has a light transmittance.

  The portion of each ink tank 10 that faces the window portion 102 has light transmittance. Therefore, the user can visually recognize the amount of ink IK in the four ink tanks 10 through the window portion 102. Each ink tank 10 is provided with an upper limit mark 3 at a portion facing the window portion 102. The upper limit mark 3 indicates the upper limit of the liquid level of the ink IK as a guide so as not to overflow from the ink tank 10 when the user injects the ink IK. Further, the user can grasp the amount of ink IK in each ink tank 10 by using the upper limit mark 3 as a mark.

  In the present embodiment, the capacity of the ink tank 10a is larger than the capacity of the ink tanks 10b, 10c, and 10d. The capacities of the ink tanks 10b, 10c, and 10d are the same. It is assumed that the printer 110 consumes more black ink IK than the color ink IK. Therefore, among the four ink tanks 10, the capacity of the ink tank 10a containing the black ink IK is larger than the capacity of the ink tanks 10b, 10c and 10d containing the color ink IK. The ink tank 10a containing the black ink IK is arranged on the front side of the printer 110 so that the user can easily grasp the remaining amount.

  The arrangement order from the front side of the ink tanks 10b, 10c, 10d in which the color ink IK is accommodated is not particularly limited. Further, when any of the color ink IK is consumed more than the black ink IK, the ink IK may be accommodated in the ink tank 10a having a large capacity.

  A cover 103 is provided on the upper portion of the case portion 101. The cover 103 is rotatably engaged with the case unit 101 via the hinge unit 104. When the cover 103 is opened, the four ink tanks 10 are exposed. For example, when the user injects ink IK into the ink tank 10, the ink tank 10 can be accessed by rotating the cover 103 and opening it upward.

<Printer configuration>
Next, the configuration of the printer according to the first embodiment will be described with reference to FIG. FIG. 2 is a schematic configuration diagram of the printer according to the first embodiment. As shown in FIG. 2, the printer 110 according to the first embodiment includes a carriage 20, a paper feed motor 30, a carriage motor 33, a paper feed roller 34, a control unit 40, and a storage unit 50. ing. In FIG. 2, the scanner 120 is omitted.

  A print head 22 is mounted on the carriage 20. The print head 22 has a plurality of nozzles that eject ink IK on the lower surface side (−Z-axis direction side) of the carriage 20. A tube 21 is provided between the print head 22 and each ink tank 10. Each ink IK in the ink tank 10 is sent to the print head 22 via the tube 21. The print head 22 ejects each ink IK sent from the ink tank 10 to the print medium P from a plurality of nozzles as ink droplets.

  The carriage 20 is connected to the control unit 40 by a cable (not shown). The carriage 20 reciprocates on the print medium P along the main scanning direction HD by being driven by the carriage motor 33. The paper feed motor 30 rotates the paper feed roller 34 and transports the print medium P in the sub-scanning direction VD. The ejection control of the print head 22 is performed by the control unit 40 via a cable.

  That is, in the printer 110, the control unit 40 controls the paper feed motor 30, the carriage motor 33, and the print head 22, so that the carriage 20 is conveyed in the sub-scanning direction VD while moving along the main scanning direction HD. Printing on the print medium P is performed by ejecting ink IK from the plurality of nozzles of the print head 22 to the print medium P to be printed.

  One end of the carriage 20 in the main scanning direction HD is a home position area in which the carriage 20 stands by. In the home position area, for example, a cap (not shown) for performing maintenance such as cleaning of the nozzles of the print head 22 is disposed. FIG. 2 shows a state where the carriage 20 is located at the home position.

  In addition, waste ink for receiving waste ink when flushing or cleaning the print head 22 is disposed at the other end portion in the main scanning direction HD in the movement region of the carriage 20 (end portion opposite to the home position). A box (not shown) or the like is arranged. Note that flushing means that ink IK is ejected from each nozzle of the print head 22 during printing of the print medium P regardless of printing. Cleaning refers to cleaning the inside of the print head 22 by sucking the print head 22 with a pump or the like provided in the waste ink box without driving the print head 22.

  An operation panel 111 including a display unit 47 is connected to the control unit 40. When the user operates the operation panel 111, the printer 110 and the scanner 120 can be operated by the control unit 40.

  For example, in FIG. 1, after setting a document on the auto document feeder 122 of the scanner 120, the user operates the operation panel 111 to start the operation of the printer system 100. Then, the original is read by the scanner 120. Subsequently, based on the read image data of the original, the printing medium P is fed from the paper cassette 114 into the printer 110 (case unit 112), and printing is performed on the printing medium P by the printer 110.

  As shown in FIG. 2, a computer 49 can be connected to the control unit 40 via an interface (I / F) 48. The control unit 40 receives image data from the computer 49 via the interface 48, and controls the printer 110 (print head 22) to print the image on the print medium P. The control unit 40 controls the scanner 120 to read a document and transmit the image data to the computer 49 via the interface 48 or to print the read image.

  The control unit 40 is connected to the detection substrate 25 of the detection unit 23 disposed in the ink tank 10 via the flexible flat cable 31. The flexible flat cable 31 includes a signal line that electrically connects the control unit 40 and the detection board 25. The detection unit 23 includes a detection substrate 25 and an optical sensor unit 26 (see FIG. 4). The configuration of the detection unit 23 will be described later.

  The control unit 40 includes a drive control unit 41, a consumption amount calculation unit 42, a liquid level decrease determination unit 43, and an ink remaining amount determination unit 44. The control unit 40 includes a CPU, a ROM, a RAM, and the like (not shown). For example, the control unit 40 operates as each unit of the control unit 40 when the control program stored in the ROM is expanded in the RAM and the CPU executes the control program expanded in the RAM. Alternatively, the control unit 40 may be configured by hardware such as an ASIC (Application Specific IC) that realizes the same function as the function executed by the CPU and the control program, instead of including the CPU. Both may be comprised.

  The drive control unit 41 controls the carriage motor 33 to move the carriage 20. As a result, the carriage motor 33 drives to move the print head 22 included in the carriage 20.

  The consumption calculation unit 42 calculates the ink consumption consumed by ejecting the ink IK from each nozzle of the print head 22. The consumption calculation unit 42 starts calculating the ink consumption based on the state (initial value) where each ink tank 10 is filled with the ink IK.

  The ink consumption amount calculated by the consumption amount calculation unit 42 is the ink consumption amount used for the maintenance of the print head 22 by cleaning the nozzles of the print head 22 and the flushing in addition to the ink consumption amount by printing on the print medium P. Including. The ink consumption is a count value by a so-called dot count method. That is, the integrated ink consumption is calculated by integrating the design ink consumption consumed for each dot by the number of dots required by the image data to be printed based on the image data to be printed. .

  In the present embodiment, the ink consumption amount is the amount of each ink IK ejected from the nozzles of the print head 22 for each pass in which the carriage 20 performs one scan (the amount of ink IK per dot × the number of ejected dots). ). The calculated ink consumption amount is added to the used ink consumption amount every time a predetermined amount of ink IK is consumed during printing, every discharge, and stored in the latest consumption amount storage unit 51 of the storage unit 50. . Further, the amount of ink consumed when performing cleaning and flushing is calculated as the amount of ink IK used each time it is performed, and is stored in the latest consumption amount storage unit 51 each time.

  The liquid level lowering determination unit 43 determines whether or not the liquid level of the ink IK has decreased for each ink tank 10, that is, whether or not the ink IK is present at a predetermined position in the ink tank 10 (hereinafter, (Also referred to as “decrease in liquid level”). In the ink tank 10, a prism 24 (see FIG. 5) serving as a reflecting portion described later is arranged for each ink tank 10. And the optical sensor part 26 (refer FIG. 5) which has the light emission part 26a and the light-receiving part 26b is arrange | positioned so that the prism 24 may be opposed.

  The liquid level lowering determination unit 43 causes the light emitting unit 26a to emit light. The light receiving unit 26b outputs a detection signal according to the amount of light received from the light emitting unit 26a and reflected by the prism 24. The liquid level lowering determination unit 43 determines whether or not the ink IK is present at a predetermined position in the ink tank 10 based on the detection signal output from the light receiving unit 26b.

  A state where the liquid level lowering determination unit 43 determines that there is no ink IK at a predetermined position in the ink tank 10 is referred to as “sensor end”. Once the sensor end is determined, the consumption calculation unit 42 starts calculating the ink consumption after the sensor end for the ink tank 10 determined to be the sensor end. The count value of the ink consumption after the sensor end is updated every time a predetermined amount of ink IK is consumed, and stored in the post-detection consumption storage unit 52 of the storage unit 50.

  The liquid level decrease determination by the liquid level decrease determination unit 43 is repeatedly executed at a predetermined timing such as when the printer 110 (printer system 100) is turned on or when a print job is received. Further, the liquid level decrease determination by the liquid level decrease determination unit 43 is executed every time the unit consumption amount of ink IK is consumed during printing.

  The remaining ink level determination unit 44 is stored in the post-detection consumption storage unit 52 after the liquid level decrease determination unit 43 determines that there is no ink IK at a predetermined position in the ink tank 10 for each ink tank 10. The remaining state of the ink IK in each ink tank 10 is determined based on the ink consumption after the sensor end and the determination information set for each ink tank 10.

  As the determination of the remaining state of the ink IK, “ink low” indicating a state in which the amount of ink IK in the ink tank 10 is low, and “ink end” indicating a state in which the consumable amount of the ink IK in the ink tank 10 is exhausted. There is. The determination of the remaining state of the ink IK is performed based on the determination information stored in the determination information storage unit 53 of the storage unit 50. The determination information includes a predetermined value (hereinafter referred to as a predetermined value A) set for each ink tank 10 and a predetermined value (hereinafter referred to as a predetermined value B) for determining ink end. ).

  The ink remaining amount determination unit 44 determines that the ink level after the sensor end of the ink tank 10 is greater than or equal to the predetermined value A after the liquid level decrease determination unit 43 determines that any of the ink tanks 10 is at the sensor end. When it is determined that the ink is low.

  For the ink tank 10 determined to be in-claw, the control unit 40 generates data for displaying an “ink low notification” for notifying the user of a decrease in the remaining amount of the ink IK and prompting the user to replenish the ink IK. Output to 47. The display unit 47 displays an ink low notification based on the data.

  The remaining ink level determination unit 44 determines that the ink level when the ink level in the ink tank 10 is equal to or greater than a predetermined value B (predetermined amount A <predetermined amount B) after the liquid level lowering determination unit 43 determines that the sensor end. It is determined that the end. If it is determined that the ink end is reached, the control unit 40 stops the printing operation of the printer 110 in order to avoid an idle state in which the ejected ink IK is lost. Then, the control unit 40 generates and displays data for displaying an “ink end notification” that informs the ink tank 10 determined to be the ink end that the ink IK has run out and prompts the ink IK to be replenished. To the unit 47. The display unit 47 displays an ink end notification based on the data.

  After the printing operation is stopped due to the ink end, the user refills the ink tank 10 determined to be the ink end, presses the reset button, and the control unit 40 refills the ink IK via the operation panel 111. When the input to that effect is received, the liquid level lowering determination by the liquid level lowering determination unit 43 is executed. When it is determined that the ink IK is present at a predetermined height in the ink tank 10, a reset process is executed, and the printer 110 is ready for a printing operation.

  The storage unit 50 stores information in a nonvolatile manner and rewritable. The storage unit 50 is configured by a nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory), for example. The storage unit 50 includes a latest consumption storage unit 51, a post-detection consumption storage unit 52, and a determination information storage unit 53. The latest consumption storage unit 51, the post-detection consumption storage unit 52, and the determination information storage unit 53 may each be configured by individual nonvolatile memories, or may be divided into the same nonvolatile memory. It may be configured as a separate area. In addition, the ROM provided in the control unit 40 may serve as the function of the storage unit 50.

  The latest consumption amount storage unit 51 stores the latest value of the cumulative value of the consumption amount of each ink IK calculated by the consumption amount calculation unit 42 for each ink tank 10. The ink consumption amount stored in the consumption amount storage unit 51 is appropriately updated based on the ink consumption amount calculated by the consumption amount calculation unit 42 for each ink tank 10. When the user performs a reset process by refilling the ink tank 10 with the ink IK and pressing the reset button, the ink consumption amount stored in the latest consumption amount storage unit 51 for that ink tank 10 is cleared and initialized. Return to value.

  The post-detection consumption amount storage unit 52 stores the latest value of the cumulative value of the consumption amount of each ink IK calculated for each ink tank 10 by the consumption amount calculation unit 42 for the ink tank 10 determined to be the sensor end. It is remembered. The ink consumption amount stored in the post-detection consumption amount storage unit 52 is appropriately updated based on the calculation of the ink consumption amount by the consumption amount calculation unit 42. The user refills the ink tank 10 with the ink IK and presses the reset button. As a result of the liquid level lowering determination by the liquid level lowering determination unit 43, it is determined that the ink IK is at a predetermined height in the ink tank 10 and reset processing is performed. Is executed, the ink consumption amount stored in the post-detection consumption amount storage unit 52 for the ink tank 10 is cleared and returns to the initial value.

  The determination information storage unit 53 stores determination information for the ink remaining amount determination unit 44 to determine ink low and ink end for the ink tank 10. The determination information includes the predetermined value A and the predetermined value B described above. The predetermined value A and the predetermined value B are values set for each ink tank 10, that is, for each type of ink IK.

  The reset process is a process for replenishing the ink tank 10 determined to be ink low or ink end and initializing the ink consumption count value (returning to the initial value). The reset process is executed when the user presses the reset button on the operation panel 111. When the reset process is executed by the user's manual operation and the liquid level lowering determination unit 43 determines that the ink IK is at a predetermined height in the ink tank 10, the latest consumption storage unit 51 and the post-detection consumption storage unit 52 are detected. The ink consumption stored in is returned to the initial value, and calculation of the ink consumption is started.

<Configuration of ink supply unit>
Next, the configuration of the ink supply unit according to the first embodiment will be described with reference to FIGS. 3, 4, and 5. FIG. 3 is a perspective view illustrating a schematic configuration of the ink supply unit according to the first embodiment. FIG. 3 shows a state in which the case unit 101 is removed from the ink supply unit 1 shown in FIG. 4 and 5 are cross-sectional views of the ink tank according to the first embodiment. Specifically, FIG. 4 is a side sectional view taken along the line AA ′ in FIG. 3, and FIG. 5 is a plan sectional view taken along the line BB ′ in FIG.

  As shown in FIG. 3, the ink supply unit 1 includes four ink tanks 10a, 10b, 10c, and 10d. The ink tanks 10a, 10b, 10c, and 10d are arranged in a line along a predetermined direction (Y-axis direction). The ink tank 10 is made of, for example, a synthetic resin such as nylon or polypropylene. Each of the four ink tanks 10 may be configured separately or may be configured integrally. When the ink tank 10 is configured integrally, the ink tank 10 may be formed integrally, or four ink tanks 10 formed separately may be bundled or connected together.

  In this embodiment, the upper surface of the front (+ X direction) side portion of the ink tank 10 is lower than the upper surface of the rear (−X direction) side portion. A replenishing port 2 for injecting ink IK from the outside of the printer 110 is provided on the upper surface of the front side portion of the ink tank 10. Although not shown, the ink supply unit 1 has a cap that is detachably attached to the replenishing port 2 and prevents the ink IK from leaking out. When the user removes the cap and injects ink IK from the replenishing port 2, the ink tank 10 can be replenished with ink IK of each color. An upper limit mark 3 is provided on the front (+ X direction) side of the ink tank 10 to indicate the upper limit of the liquid level of the ink IK as a guide.

  In the ink tank 10, the Z-axis direction, the Y-axis direction, and the X-axis direction are also referred to as a height direction, a width direction, and a depth direction, respectively. As described above, the capacity of the ink tank 10a containing the black ink IK is larger than the capacity of the ink tanks 10b, 10c, and 10d containing the color ink IK. Comparing the ink tank 10a with the ink tanks 10b, 10c, 10d, the height and depth are the same, and the width of the ink tank 10a (the length in the Y-axis direction) is larger than the width of the ink tanks 10b, 10c, 10d. It is getting bigger.

  The ink IK for the user to refill the ink tank 10 is provided in a separate refill container (not shown, also referred to as a refill bottle below). In this embodiment, the capacities of the refill bottles that store the refill color ink IK are the same, but the refill bottles that store the refill black ink IK store the color ink IK. Larger than the capacity of the refill bottle.

  A detection substrate 25 is disposed on the rear (−X direction) side opposite to the replenishing port 2 of the ink tank 10. The detection board 25 extends along the Y-axis direction, which is the width direction of the ink tank 10 and the direction in which the ink tanks 10a, 10b, 10c, and 10d are arranged. The detection substrate 25 is disposed so as to face the rear surface of the ink tanks 10a, 10b, 10c, and 10d.

  In the present embodiment, four ink tanks 10 are arranged in a line, but when the number of ink tanks 10 is large, the ink tanks 10 may be arranged in a plurality of lines. In such a case, a plurality of detection substrates 25 may be arranged for each row of the ink tanks 10.

  As shown in FIG. 4, a prism 24 as a reflecting portion is disposed on the rear (−X direction) side surface in the ink tank 10. Although one ink tank 10 is shown in FIG. 4, a prism 24 is arranged on the inner surface of the same side (−X direction) of each of the four ink tanks 10a, 10b, 10c, and 10d. The prism 24 is disposed on the lower side (−Z direction) in the ink tank 10. The prism 24 is formed of a member such as polypropylene that transmits the irradiation light from the light emitting unit 26a of the optical sensor unit 26. The prism 24 is fixed by being inserted into a hole provided in a wall constituting the ink tank 10.

  The detection substrate 25 of the detection unit 23 is disposed so as to face the prism 24. On the surface (+ X direction side) facing the prism 24 of the detection substrate 25, the optical sensor unit 26 is arranged for each ink tank 10 (10a, 10b, 10c, 10d). The optical sensor unit 26 is an optical sensor, and includes a light emitting unit 26a that emits light, a light receiving unit 26b that receives reflected light of the light emitted from the light emitting unit 26a, and outputs a detection signal according to the amount of received light. Have In the present embodiment, the light emitting unit 26 a and the light receiving unit 26 b are disposed at the same position in the depth direction (X-axis direction) and the height direction (Z-axis direction) of the ink tank 10.

  The position of the light emitting unit 26 a of the optical sensor unit 26 in the height direction of the ink tank 10 is a “predetermined position” when determining a decrease in the liquid level of the ink IK in the ink tank 10. A B-B ′ line in FIG. 4 is a line that passes through the position of the light emitting unit 26 a of the optical sensor unit 26 and is parallel to the X-axis direction. Therefore, FIG. 5 is a cross-sectional plan view of FIG. 4 taken at “predetermined positions”.

  The “predetermined position” is appropriately set from the viewpoint of preventing the ink IK from running out and causing the ink to run idle. For example, assuming a predetermined lead time (for example, one week) for the user to arrange the refilling ink IK, the consumption amount for each ink IK consumed during that period is estimated. A predetermined amount of ink IK corresponding to the estimated consumption amount remains at the time when the liquid level lowering determination unit 43 determines that the liquid level is lower and the remaining ink level determining unit 44 determines that the ink level is low and the ink low notification is displayed. Is set.

  As shown in FIG. 5, the planar cross section (XY cross section) of the prism 24 viewed from the + Z direction side is a right isosceles triangle shape. The prism 24 has an inclined surface 24a, an inclined surface 24b, and a bottom surface 24c. The inclined surface 24a and the inclined surface 24b are, for example, surfaces orthogonal to each other, and the inclined surface 24a and the inclined surface 24b form an apex angle of a right isosceles triangle. The inclined surface 24a and the inclined surface 24b are disposed so as to be symmetric with respect to the XZ plane. The bottom surface 24c is a surface parallel to the YZ plane and faces the optical sensor unit 26 (the light emitting unit 26a and the light receiving unit 26b).

  In the present embodiment, the light emitting unit 26 a and the light receiving unit 26 b are arranged so as to be aligned along the width direction of the ink tank 10, that is, the extending direction (Y-axis direction) of the detection substrate 25. The light emitting portion 26a is disposed so as to face the bottom surface 24c and the inclined surface 24a of the prism 24 in the X-axis direction. The light receiving portion 26b is disposed so as to face the bottom surface 24c and the inclined surface 24b of the prism 24 in the X-axis direction.

  The side cross section (XZ cross section) of the prism 24 is a right isosceles triangle, and the light emitting portion 26a and the light receiving portion 26b intersect the height direction of the ink tank 10, that is, the extending direction of the detection substrate 25. It is good also as a structure arrange | positioned so that it may line up along the direction (Z-axis direction) to do.

<Configuration related to determination of liquid level drop using detection unit>
Next, a configuration related to determination of liquid level reduction using the detection unit according to the first embodiment will be described with reference to FIG. FIG. 6 is a diagram illustrating an electrical configuration of the detection unit according to the first embodiment. As shown in FIG. 6, the detection unit 23 according to the present embodiment includes a detection substrate 25, an optical sensor unit 26, and a multiplexer 27 as a selection circuit. The detection unit 23 includes four optical sensor units 26 corresponding to the four ink tanks 10 (see FIG. 3). Each optical sensor unit 26 includes a light emitting unit 26a and a light receiving unit 26b. The four optical sensor units 26 and the multiplexer 27 are arranged on the detection substrate 25.

  The light emitting unit 26a is configured by a light emitting element such as an LED (Light Emitting Diode), for example. The light emitting section 26a in each of the four ink tanks 10 (10a, 10b, 10c, 10d) emits light when the transistor TR1 is on and the power supply potential Vcc is connected to the light emitting section 26a. On / off of the transistor TR1 is controlled by a PWM (Pulse Width Modulation) signal input to the transistor TR1. The amount of light emitted from the light emitting unit 26a is set by adjusting the duty ratio of the PWM signal (ratio between on time and off time) by the control unit 40.

  For example, the light receiving unit 26b includes a light receiving element such as a phototransistor. The emitter terminal of the light receiving unit 26b is connected to the ground potential VSS. The collector terminal of the light receiving unit 26b is connected to the multiplexer 27, and is connected to the power supply potential Vcc through the resistance element R1. When the light emitted from the light emitting unit 26a is reflected by the prism 24 (see FIG. 5) in the ink cartridge 10 and the reflected light is received by the light receiving unit 26b, the light receiving unit 26b outputs an output voltage corresponding to the amount of light received. Is output as a detection signal.

  The multiplexer 27 is connected to the collector terminals of the light receiving portions 26b of the four photosensor portions 26. The control unit 40 sends a selection signal for selecting the optical sensor unit 26 of one ink tank 10 out of the four ink tanks 10 via a signal line arranged on the flexible flat cable 31 (see FIG. 2). Transmit to the multiplexer 27. Based on the selection signal from the control unit 40, the multiplexer 27 sends the detection signal from the light receiving unit 26 b of the selected optical sensor unit 26 to the control unit 40 (liquid level lowering determination) via the A / D conversion unit 28. Part 43). The A / D converter 28 is provided in the controller 40.

  The potential between the collector terminal of the light receiving unit 26b selected by the multiplexer 27 and the resistance element R1 is input to the A / D conversion unit 28 as the output voltage of the light receiving unit 26b. The A / D converted output voltage of the light receiving unit 26 b is input to the liquid level lowering determination unit 43. As a result, the detection signal of the light receiving unit 26 b of one ink tank 10 selected based on the selection signal from the control unit 40 among the four ink tanks 10 is input to the liquid level lowering determination unit 43.

  Thus, in this embodiment, the detection signal from the light receiving unit 26b of the ink tank 10 selected by the multiplexer 27 based on the selection signal from the control unit 40 among the four ink tanks 10 is the liquid level lowering determination unit. 43. Therefore, as compared with the case where the multiplexer 27 is not provided, the number of ports of the control unit 40 and the detection board 25 and the number of signal lines that electrically connect the control unit 40 and the detection board 25 can be reduced.

  For example, when the number of the ink tanks 10 is four and the number of the optical sensor units 26 is four corresponding to the number of the ink tanks 10, if there is no multiplexer 27, the detection board 25 of the control unit 40 has Each of the number of ports to be connected and the number of ports on the detection board 25 requires a total of five, one output port for the light emitting unit 26a and four input ports for the light receiving unit 26b. The number of signal lines connecting these ports of the control unit 40 and the detection board 25 is also five. On the other hand, when there is the multiplexer 27 as in this embodiment, the number of ports in the control unit 40 is one output port for the light emitting unit 26a and two output ports for the multiplexer 27 (this is The multiplexer 27 corresponds to two signals for selecting one of the four ink tanks 10) and one input port for the multiplexer 27, and the number of signal lines is also four. Become one.

  When there are eight ink tanks 10 and the number of light sensor units 26 is eight corresponding to the number of ink tanks 10, if there is no multiplexer 27, the number of ports in the control unit 40 is for the light emitting unit 26a. 9 in total, one output port and eight input ports for the light receiving unit 26b are required. The number of signal lines connecting these ports of the control unit 40 and the detection board 25 is also nine. On the other hand, when there is the multiplexer 27 as in this embodiment, the number of ports in the control unit 40 is one output port for the light emitting unit 26a and three output ports for the multiplexer 27 (eight inks). Corresponding to three signals for selecting one of the tanks 10) and one input port for the multiplexer 27, and the number of signal lines is also five.

  Thus, by providing the multiplexer 27, the number of ports of the control unit 40, the number of ports of the detection board 25, and the number of signal lines connecting the ports of the control unit 40 and the detection board 25 are as follows. Less. As the number of ink tanks 10 increases, the effect of reducing the number of ports and the number of signal lines of the control unit 40 can be increased.

  In the present embodiment, the light emitting unit 26a in each of the four ink tanks 10 emits light, the light receiving unit 26b that receives the reflected light outputs a detection signal, and the light receiving unit 26b of the selected one ink tank 10 Although only the detection signal is configured to be input to the liquid level decrease determination unit 43, the present invention is not limited to such a form. Only the light emitting part 26a of the selected one of the four ink tanks 10 emits light, and the detection signal of the light receiving part 26b of the selected ink tank 10 is input to the liquid level lowering determination part 43. Also good.

<Method for determining liquid level drop>
Next, a method for determining the decrease in the liquid level of the ink IK in the ink tank 10 by the optical sensor unit 26 of the detection unit 23 according to the first embodiment will be described with reference to FIGS. 4, 5, 7, and 8. The description will be given with reference. 7 and 8 are cross-sectional views of the ink tank according to the first embodiment. Specifically, FIG. 7 is a side sectional view taken along the line AA ′ in FIG. 3, and FIG. 8 is a plan sectional view taken along the line BB ′ in FIG. 4 and 5 show the case where the liquid level of the ink IK is higher than the predetermined position, and FIGS. 7 and 8 show the case where the liquid level of the ink IK is lower than the predetermined position.

  In FIG. 4, the liquid level of the ink IK in the ink tank 10 is higher than the height at which the prism 24 is immersed, and is higher than a predetermined position where the light emitting part 26a is disposed. Therefore, as shown in FIG. 5, the inclined surface 24a and the inclined surface 24b of the prism 24 are in contact with the ink IK. In this state, the light emitted from the light emitting unit 26a and incident on the prism 24 enters the ink IK from the inclined surface 24a.

  For example, assuming that the refractive index of the ink IK is 1.5, which is substantially the same as the refractive index of water, and the prism 24 is made of polypropylene, the critical angle of total reflection at the inclined surfaces 24a and 24b is about 64 degrees. It becomes. Since the incident angle of the light emitted from the light emitting unit 26a is 45 degrees, the light incident on the prism 24 enters the ink IK without being totally reflected by the inclined surface 24a and the inclined surface 24b. Accordingly, since the light reflected by the inclined surfaces 24a and 24b is very small, almost no detection voltage is output when the light receiving unit 26b receives the reflected light reflected by the inclined surfaces 24a and 24b. Not.

  Next, consider a case where the ink IK in the ink tank 10 is consumed for printing and the liquid level of the ink IK is lowered. In FIG. 7, the liquid level of the ink IK in the ink tank 10 is lower than a predetermined position where the light emitting unit 26a is disposed. Therefore, as shown in FIG. 8, at a predetermined position in the ink tank 10, the inclined surface 24a and the inclined surface 24b of the prism 24 are in contact with air. In this state, light emitted from the light emitting unit 26a and incident on the prism 24 is totally reflected by the inclined surface 24a and the inclined surface 24b, and the reflected light is emitted to the outside of the prism 24 (on the light receiving unit 26b side). Light is received by the light receiving unit 26b.

  For example, when the refractive index of air is 1 and the prism 24 is made of polypropylene, the critical angle of total reflection on the inclined surface 24a and the inclined surface 24b is about 43 degrees. Since the incident angle of the light emitted from the light emitting unit 26a is 45 degrees, the light incident on the prism 24 is totally reflected by the inclined surface 24a and the inclined surface 24b. Therefore, since the light receiving unit 26b receives the reflected light totally reflected by the inclined surfaces 24a and 24b, a large detection voltage is output from the light receiving unit 26b.

  As described above, whether or not the liquid level of the ink IK has decreased based on the detection signal (the magnitude of the detection voltage) output from the light receiving unit 26b of the optical sensor unit 26 to the liquid level decrease determination unit 43 of the control unit 40. That is, it can be determined whether or not the ink IK is present at a predetermined position in the ink tank 10.

  In the height direction (Z-axis direction) of the ink tank 10 in FIGS. 4 and 7, it is preferable that the position of the central portion of the prism 24 is the same as the predetermined position where the light emitting portion 26a is disposed. 5 and 8, the apex angle of the prism 24 having a right isosceles triangle in the width direction (Y-axis direction) of the ink tank 10 is the center of the light sensor unit 26 (the light emitting unit 26a and the light receiving unit 26b). It is preferable that the position is the same as the position of the central portion.

  Here, the effects of the configuration of the printer 110 according to the present embodiment will be described in comparison with the configuration of a conventional printer. For example, in the printer described in Patent Document 1, an optical sensor is disposed on a carriage on which a print head is disposed (see FIG. 1 of Patent Document 1). Each of the plurality of ink cartridges is provided with a prism-like reflecting member (hereinafter referred to as a prism) at a position facing an optical sensor that moves with the carriage in the movement path of the carriage.

  In the printer described in Patent Document 1, when detecting the remaining amount of ink in the ink cartridge, the optical sensor arranged on the carriage is moved with respect to the plurality of ink cartridges. Therefore, unless the ink cartridges are arranged in a line along the moving direction of the carriage, the optical sensor cannot face the prism of each ink cartridge. Accordingly, the arrangement direction of the ink cartridge is limited to the carriage movement direction. That is, there are restrictions on the position of the ink cartridge in the printer device design.

  Further, since the optical sensor disposed on the carriage is moved when detecting the remaining amount of ink, the relative positional relationship between the prism of each ink cartridge and the optical sensor changes. For this reason, the light from the light emitting element of the optical sensor is also applied to the part other than the inclined surface of the prism, and the reflected light received by the light receiving element of the optical sensor is totally reflected by the two inclined surfaces of the prism. In addition to light, for example, noise components such as reflected light reflected from the bottom surface of the ink cartridge or the bottom surface of the prism may be included. If the response speed of the light receiving element (such as a phototransistor) cannot follow the moving speed of the carriage, the detection voltage from the light receiving element becomes small. In these cases, the detection accuracy of the remaining amount of ink is lowered.

  Furthermore, when detecting the remaining amount of ink, it is necessary to move the carriage on which the print head is mounted. For this reason, there are restrictions on the timing for detecting the remaining amount of ink, and if the remaining amount of ink is frequently detected, the throughput of printing is reduced.

  On the other hand, according to the configuration of the printer 110 according to the first embodiment, the same side (−X direction side) surface of the plurality of ink tanks 10 arranged along a predetermined direction (Y-axis direction). An optical sensor unit 26 having a light emitting unit 26 a and a light receiving unit 26 b is arranged for each ink tank 10 so as to face the prism 24 arranged for each ink tank 10. That is, when the control unit 40 determines the liquid level drop of the ink IK, it is not necessary to move the carriage 20, and the positional relationship between the prism 24 and the optical sensor unit 26 of each ink tank 10 does not change.

  Therefore, the arrangement position of the ink tank 10 in the device design of the printer 110 can be determined without being restricted by the movement direction (X-axis direction) of the carriage 20. Then, by optimizing the arrangement position of the ink tank 10 in the printer 110, the length of the printer 110 in the movement direction of the carriage 20 can be made smaller than in the case where the ink tank 10 is arranged along the movement direction of the carriage 20. It is possible to reduce the outer shape of the printer 110.

  When the number of ink tanks 10 is large, the ink tanks 10 may be arranged in a plurality of rows. In this way, as compared with the case where the ink tanks 10 are arranged in a line, the degree of freedom of the arrangement position of the ink tank 10 in the device design of the printer 110 is increased, and the outer shape of the printer 110 can be further downsized. It becomes.

  Further, according to the configuration of the printer 110 according to the first embodiment, the relative positional relationship between the prism 24 of the ink tank 10 and the optical sensor unit 26 does not change when the liquid level reduction determination of the ink IK is performed. Therefore, the light from the light emitting unit 26 a is irradiated to a specific position on the inclined surface 24 a of the prism 24. Thereby, it is possible to prevent the reflected light received by the light receiving unit 26b from including reflected light (noise component) other than the reflected light totally reflected by the inclined surfaces 24a and 24b of the prism 24. Since the positional relationship between the prism 24 and the light receiving unit 26b does not change, the response speed of the phototransistor constituting the light receiving unit 26b does not affect the detection voltage.

  Furthermore, according to the configuration of the printer 110 according to the first embodiment, it is not necessary to move the carriage 20 on which the print head 22 is mounted when the liquid level reduction determination of the ink IK is performed. Therefore, the timing at which the ink level decrease determination of the ink IK is not restricted, and a decrease in printing throughput due to the ink level decrease determination of the ink IK can be suppressed.

(Second Embodiment)
Next, a second embodiment will be described. In the second embodiment, the basic configuration of the printer and the printer system is the same as that of the first embodiment, but a reflection plate is provided instead of the prism as the reflection unit arranged in the ink tank. Is different. Hereinafter, the configuration of the ink tank and the method for determining the decrease in the ink level according to the second embodiment will be described with reference to FIGS. 9, 10, 11, and 12. Here, differences from the first embodiment will be described, and the same components as those in the first embodiment will be denoted by the same reference numerals and description thereof will be omitted.

  9, FIG. 10, FIG. 11, and FIG. 12 are cross-sectional views of ink tanks according to the second embodiment. Specifically, FIG. 9 corresponds to a side sectional view taken along the line A-A ′ in FIG. 3, and FIG. 10 is a plan sectional view taken along the line B-B ′ in FIG. 9. 11 corresponds to a side sectional view taken along the line A-A ′ of FIG. 3, and FIG. 12 is a plan sectional view taken along the line B-B ′ of FIG. 11. 9 and 10 show the case where the liquid level of the ink IK is higher than the predetermined position, and FIGS. 11 and 12 show the case where the liquid level of the ink IK is lower than the predetermined position.

<Configuration of ink tank>
As shown in FIG. 9, a reflection plate 29 as a reflection portion is disposed on the front (+ X direction) side of the ink tank 60 as a liquid container according to the second embodiment. In the present embodiment, the reflection plate 29 is disposed outside the ink tank 60 so as to face the optical sensor unit 26 via the ink tank 60. The reflecting plate 29 is composed of, for example, a base material and a metal film having a high reflectance such as aluminum formed on the base material. Note that the portion of the ink tank 60 facing the optical sensor unit 26 and the portion where the reflecting plate 29 is disposed have light transmittance.

<Method for determining liquid level drop>
As shown in FIGS. 9 and 10, the ink IK is interposed between the optical sensor unit 26 (light emitting unit 26 a) and the reflection plate 29 in a state where the liquid level of the ink IK is higher than a predetermined position. That is, the reflecting plate 29 is opposed to the light emitting unit 26a via the ink IK. In this state, as shown in FIG. 10, the light emitted from the light emitting unit 26 a toward the reflecting plate 29 enters the ink tank 60. The light that has entered the ink tank 60 is attenuated by the ink IK and does not reach the reflection plate 29. Even if a part of the light incident in the ink tank 60 reaches the reflection plate 29, the reflected light reflected by the reflection plate 29 is further attenuated by the ink IK, so that the light receiving unit 26b receives the reflected light. Therefore, almost no detection voltage is output.

  As shown in FIGS. 11 and 12, the ink IK is not interposed between the optical sensor unit 26 (light emitting unit 26 a) and the reflection plate 29 in a state where the liquid level of the ink IK is lower than a predetermined position. In this state, as shown in FIG. 12, the light emitted from the light emitting unit 26 a toward the reflecting plate 29 is transmitted through the ink tank 60 and reflected by the reflecting plate 29. Then, since the reflected light reflected by the reflecting plate 29 passes through the ink tank 60 again and enters the light receiving unit 26b, a large detection voltage is output from the light receiving unit 26b. Accordingly, also in the second embodiment, the ink IK is detected based on the detection signal (the magnitude of the detection voltage) output from the light receiving unit 26b of the optical sensor unit 26 to the liquid level lowering determination unit 43 of the control unit 40. It can be determined whether or not the liquid level has dropped, that is, whether or not the ink IK is present at a predetermined position in the ink tank 60.

  Also in the second embodiment, the carriage 20 does not move when the liquid level reduction determination of the ink IK is performed, and the positional relationship between the reflection plate 29 and the optical sensor unit 26 does not change. Therefore, also in the second embodiment, the same effect as in the first embodiment can be obtained.

  In the above-described example, the reflection plate 29 is arranged outside the ink tank 60. However, the reflection plate 29 may be arranged inside the ink tank 60. However, in the configuration in which the reflecting plate 29 is disposed inside the ink tank 60, when the material of the reflecting plate 29 and the ink IK cause a chemical reaction, the reflectance of the reflecting plate 29 is lowered and the ink IK is contaminated. There is a fear. Therefore, when the reflecting plate 29 is disposed inside the ink tank 60, it is preferable to use a material that hardly causes a chemical reaction with the ink IK for the reflecting plate 29.

  The above-described embodiments merely show one aspect of the present invention, and can be arbitrarily modified and applied within the scope of the present invention. As modifications, for example, the following can be considered.

(Modification 1)
In the above-described embodiment, the optical sensor unit 26 determines whether the liquid level of the ink IK in the ink tank 10 is lowered. However, the present invention is not limited to such a form. For example, the optical sensor unit 26 may determine whether or not the ink IK is present at a certain position in the ink tank 10. According to such a configuration, for example, when the user refills the ink IK into the ink tank 10 from the replenishing port 2, the optical sensor unit 26 determines whether or not the liquid level of the ink IK has reached the upper limit. be able to.

(Modification 2)
In the above embodiment, the prism 24 is inserted into the hole provided in the wall constituting the ink tank 10, but the present invention is not limited to such a form. For example, the prism 24 and the wall constituting the ink tank 10 may be integrally molded.

(Modification 3)
In the above embodiment, the ink tanks 10 and 60 are arranged in the main body of the printer 110, but the present invention is not limited to such a form. For example, the present invention can be applied even if the ink tanks 10 and 60 are arranged on the carriage 20.

(Modification 4)
In the above-described embodiment, the liquid container has the ink tanks 10 and 60 fixed to the printer 110, and the user can replenish the ink IK from the replenishing port 2. It is not limited to such a form. For example, the present invention can be applied even when the liquid container includes an ink cartridge that is detachably attached to a printer.

(Modification 5)
In the above embodiment, the upper limit mark 3 is provided in the ink tanks 10 and 60, but the present invention is not limited to such a form. For example, instead of the upper limit mark 3 or in addition to the upper limit mark 3, a lower limit mark indicating a level at which the ink tanks 10 and 60 need to be replenished with ink IK may be provided. When the lower limit mark is provided, the user checks the remaining amount of the ink IK in each of the ink tanks 10 and 60 with the lower limit mark as a mark, and grasps whether or not the ink IK needs to be replenished. Can do.

(Modification 6)
In the above embodiment, the printer system 100 that is a multifunction machine including the printer 110 and the scanner 120 as a printing apparatus has been described as an example. However, the present invention is not limited to such a form. The printing apparatus may be a single-function printer 110 that does not include the scanner 120.

(Modification 7)
In the above embodiment, an example in which the present invention is applied to a printer and an ink tank has been described, but the present invention is not limited to such a form. The present invention may be used, for example, in a printing apparatus that ejects or discharges liquid other than ink, and is also applicable to a liquid container that contains such liquid.

  2 ... replenishment port 10, 10a, 10b, 10c, 10d, 60 ... ink tank (liquid container), 20 ... carriage, 22 ... print head, 23 ... detection unit, 24 ... prism (reflection unit), 25 ... detection substrate , 26 ... optical sensor part, 26 a ... light emitting part, 26 b ... light receiving part, 27 ... multiplexer (selection circuit), 29 ... reflector (reflecting part), 40 ... control part, 43 ... liquid level lowering determination part, 110 ... Printer (printing device), IK ... ink (liquid).

Claims (6)

A plurality of liquid containers arranged in a predetermined direction and containing a liquid;
A reflective portion disposed for each liquid container on the same side surface in a direction intersecting the predetermined direction of the liquid container;
A detection substrate disposed so as to face the reflection portion of the liquid container, and a light emitting portion for irradiating light disposed on the surface of the detection substrate facing the reflection portion for each liquid container; A light receiving unit that outputs a detection signal according to the amount of received reflected light of the light emitted from the light emitting unit;
A control unit that irradiates the light to the light emitting unit and determines whether or not the liquid is present at a predetermined position in the liquid container based on the detection signal output from the light receiving unit;
A carriage on which a print head for ejecting the liquid is disposed;
A printing apparatus comprising: The printing apparatus according to claim 1,
The detection unit further includes a selection circuit disposed on the detection board,
The control unit transmits a selection signal for selecting the detection unit of one of the plurality of liquid containers to the selection circuit,
The selection circuit transmits the detection signal from the light receiving unit of the selected detection unit to the control unit based on the selection signal. The printing apparatus according to claim 1, wherein:
The printing apparatus according to claim 1, wherein the liquid container includes a refill port through which a user can refill the liquid. The printing apparatus according to any one of claims 1 to 3,
The main scanning direction of the carriage is a direction crossing the predetermined direction. The printing apparatus according to any one of claims 1 to 4,
The printing apparatus according to claim 1, wherein the reflection unit is a prism disposed on the detection unit side in the liquid container. The printing apparatus according to any one of claims 1 to 4,
The printing apparatus according to claim 1, wherein the reflection unit is a reflection plate facing the detection unit via the liquid when the liquid container is filled with the liquid.

Images