JP2021030486A - Printing device - Google Patents

Abstract

To provide a printing device that can execute notification processing using a light source that is used for ink amount detection processing.SOLUTION: A printing device includes: an ink tank 310; a print head 107 for performing printing using ink IK stored in the ink tank; a light source 323 for emitting light into the ink tank; a sensor 190 for outputting pixel data by detecting incident light from an ink tank side in the period where the light source 323 emits light; a processing part 120 for determining an ink amount depending on output from the sensor 190; and a light guide body 112 for guiding light from the light source 323 to the outside of a housing.SELECTED DRAWING: Figure 40

Description

The present invention relates to a printing apparatus or the like.

Conventionally, in a printing apparatus that prints using ink, a method of determining the presence or absence of ink in an ink container has been known. For example, Patent Document 1 discloses an ink supply device that detects the liquid level of ink by receiving light emitted from a light emitter and passing through an ink bottle by using a light receiver.

Japanese Unexamined Patent Publication No. 2001-105627

Further improvement of the printing apparatus was required.

One aspect of the present disclosure is an ink tank, a print head that prints using the ink in the ink tank, a light source that irradiates the ink tank with light, and the ink tank side during a period in which the light source emits light. The present invention relates to a printing apparatus including a sensor that detects light incident from the printer, a processing unit that determines the amount of ink based on the output of the sensor, and a light guide that guides the light from the light source to the outside of the housing.

The perspective view which shows the structure of an electronic device. The figure explaining the arrangement of the ink tank in an electronic device. A perspective view of an electronic device with the lid of the ink tank unit opened. The perspective view which shows the structure of the ink tank. Configuration example of printer unit and ink tank unit. Exploded view of the sensor unit. The figure which shows the positional relationship of a substrate, a photoelectric conversion device, and a light source. Sectional view of the sensor unit. The figure explaining the positional relationship of an ink tank, a light source, and a photoelectric conversion device. The figure explaining the positional relationship between a light source and a light guide body. The figure explaining the positional relationship between a light source and a light guide body. The figure explaining the positional relationship between a light source and a light guide body. Configuration example of sensor unit and processing unit. Configuration example of photoelectric conversion device. The figure explaining the pitch of a lens, the pixel pitch, and the unevenness of light amount. Other configuration examples of photoelectric conversion devices. An example of pixel data that is the output of the sensor. A flowchart illustrating an ink amount detection process. The figure explaining the positional relationship between an ink tank and a photoelectric conversion device. An explanatory diagram of a process of acquiring low-resolution pixel data by thinning out pixels. Explanatory drawing of the process of acquiring high-resolution pixel data in a reading area. The flowchart explaining the two-step ink amount detection process. Setting example of the first area to the third area. Setting example of the first read area and the second read area. Setting example of the first read area and the second read area. Setting example of the first read area and the second read area. Examples of the spectral emission characteristics of the light source and the spectral reflection characteristics of the ink. Example of pixel data of pigment black ink. Example of pixel data of pigment cyan ink. An example of pixel data for pigment magenta ink. Example of pixel data of pigment yellow ink. Example of pixel data of pigment white ink. Example of pixel data of pigment clear ink. The flowchart explaining the ink type determination process based on the predicted ink color. The flowchart explaining the ink type determination process. An example of a combination pattern of light intensity characteristics. The flowchart explaining the ink type determination process. An explanatory diagram of the positional relationship between the sensor unit and the light guide body that guides light to the outside of the housing. An explanatory diagram of the positional relationship between the sensor unit and the light guide body that guides light to the outside of the housing. The explanatory view of the positional relationship between the sensor unit and the light guide body in the on-carriage type printing apparatus. The figure explaining the control method of a plurality of light sources. A perspective view of an electronic device when using a scanner unit.

Hereinafter, this embodiment will be described. The present embodiment described below does not unreasonably limit the contents described in the claims. Moreover, not all of the configurations described in the present embodiment are essential configuration requirements. The plurality of embodiments described below may be combined with each other or interchanged.

1. 1. Configuration Example of Electronic Device 1.1 Basic Configuration of Electronic Device FIG. 1 is a perspective view of the electronic device 10 according to the present embodiment. The electronic device 10 is a multifunction device (MFP: Multifunction Peripheral) including a printer unit 100 and a scanner unit 200. Further, the electronic device 10 may have other functions such as a facsimile function in addition to the printing function and the scanning function. Alternatively, it may have only a printing function. The electronic device 10 also includes an ink tank unit 300 that houses the ink tank 310. The printer unit 100 is an inkjet printer that executes printing using the ink supplied from the ink tank 310. Hereinafter, the description of the electronic device 10 can be appropriately read as a printing device.

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 a positive direction, and the direction opposite to the direction of the arrow indicates a negative direction. Hereinafter, the positive direction of the X-axis is referred to as + X direction, and the negative direction is referred to as −X direction. The same applies to the Y-axis and the Z-axis. The electronic device 10 is arranged on a horizontal plane defined by the X-axis and the Y-axis in its used state, and the + Y direction is the front surface of the electronic device 10. The Z axis is an axis orthogonal to a horizontal plane, and the −Z direction is the vertical downward direction.

The electronic device 10 has an operation panel 101 as a user interface unit. On the operation panel 101, for example, buttons for turning on / off the power of the electronic device 10, an operation related to printing using the printing function, and an operation related to reading a document using the scanning function are arranged. Further, on the operation panel 101, a display unit 150 for displaying an operating state of the electronic device 10 and a message and the like is arranged. Further, the display unit 150 displays the amount of ink detected by the method described later. Further, the operation panel 101 may be provided with a reset button for the user to replenish the ink tank 310 with ink and execute the reset process.

1.2 Printer Unit and Scanner Unit The printer unit 100 prints on a printing medium P such as printing paper by injecting ink. The printer unit 100 has a case portion 102 which is an outer shell of the printer unit 100. A front cover 104 is provided on the front side of the case portion 102. The front surface here represents a surface on which the operation panel 101 is provided, and represents a surface of the electronic device 10 in the + Y direction. The operation panel 101 and the front cover 104 are rotatable about the X-axis with respect to the case portion 102. The electronic device 10 includes a paper cassette (not shown), and the paper cassette is provided in the −Y direction with respect to the front cover 104. The paper cassette is connected to the front cover 104 and is detachably attached to the case portion 102. An output tray (not shown) is provided in the + Z direction of the paper cassette, and the output tray can be expanded and contracted in the + Y direction and the −Y direction. The output tray is provided in the −Y direction with respect to the operation panel 101 in the state of FIG. 1, and is exposed to the outside by rotating the operation panel 101.

The X-axis is the main scanning axis HD of the print head 107, and the Y-axis is the sub-scanning axis VD of the printer unit 100. A plurality of print media P are placed on the paper cassette in a laminated state. The print media P placed on the paper cassette are supplied one by one to the inside of the case portion 102 along the sub-scanning axis VD, printed by the printer unit 100, and then discharged along the sub-scanning axis VD. It is placed on the output tray.

The scanner unit 200 is mounted on the printer unit 100. The scanner unit 200 has a case portion 201. The case portion 201 constitutes the outer shell of the scanner unit 200. The scanner unit 200 is a flatbed type and has a platen formed of a transparent plate-like member such as glass and an image sensor. The scanner unit 200 reads an image or the like recorded on a medium such as paper as image data via an image sensor. Further, the electronic device 10 may include an auto document feeder (not shown). The scanner unit 200 sequentially feeds a plurality of stacked documents while inverting them one by one by an auto document feeder, and reads them using an image sensor.

1.3 Ink tank unit and ink tank The ink tank unit 300 has a function of supplying ink IK to the print head 107 included in the printer unit 100. The ink tank unit 300 includes a case portion 301, and the case portion 301 has a lid portion 302. A plurality of ink tanks 310 are housed in the case portion 301.

FIG. 2 is a diagram showing an accommodation state of the ink tank 310. The portion shown by the solid line in FIG. 2 represents the ink tank 310. A plurality of ink IKs of different types are individually housed in the plurality of ink tanks 310. That is, the plurality of ink tanks 310 contain different types of ink IK for each ink tank 310.

In the example of FIG. 2, the ink tank unit 300 accommodates five ink tanks 310a, 310b, 310c, 310d, 310e. Further, in the present embodiment, five types of ink, two types of black ink and five types of yellow, magenta, and cyan color inks are adopted. The two types of black ink are pigment ink and dye ink. Ink IKa, which is a black pigment ink, is housed in the ink tank 310a. The ink tanks 310b, 310c, and 310d contain yellow, magenta, and cyan color inks IKb, IKc, and IKd. Ink IKe, which is a black dye ink, is housed in the ink tank 310e.

The ink tanks 310a, 310b, 310c, 310d, and 310e are arranged so as to be arranged along the + X direction in this order, and are fixed in the case portion 301. In the following, when the five ink tanks 310a, 310b, 310c, 310d, 310e and the five types of inks IKa, IKb, IKc, IKd, and IKe are not distinguished, they are simply referred to as ink tanks 310 and ink IK.

In the present embodiment, each of the five ink tanks 310 has a configuration in which ink IK can be injected into the ink tank 310 from the outside of the electronic device 10. Specifically, the user of the electronic device 10 injects ink IK contained in another container into the ink tank 310 to replenish the ink.

In the present embodiment, the capacity of the ink tank 310a is larger than the capacity of the ink tanks 310b, 310c, 310d, 310e. The capacities of the ink tanks 310b, 310c, 310d, and 310e are the same. In the printer unit 100, it is assumed that the pigment black ink IKa is consumed more than the color inks IKb, IKc, IKd and the dye black ink IKe. The ink tank 310a containing the pigment black ink IKa is arranged at a position close to the central portion of the electronic device 10 on the X-axis. In this way, for example, when the case portion 301 has a window portion for allowing the user to visually recognize the side surface of the ink tank 310, it becomes easy to check the remaining amount of frequently used ink. However, the arrangement order of the five ink tanks 310a, 310b, 310c, 310d, and 310e is not particularly limited. Further, when any of the other inks IKb, IKc, IKd, and IKe is consumed more than the black pigment ink IKa, the ink IK may be stored in the ink tank 310a having a large capacity.

FIG. 3 is a perspective view of the electronic device 10 in a state where the lid 302 of the ink tank unit 300 is opened. The lid portion 302 is rotatable with respect to the case portion 301 via the hinge portion 303. When the lid 302 is opened, the five ink tanks 310 are exposed. More specifically, opening the lid 302 exposes five caps corresponding to each ink tank 310, and opening the cap exposes a part of the ink tank 310 in the + Z direction. A part of the ink tank 310 in the + Z direction is an area including the ink injection port 311 of the ink tank 310. When injecting ink IK into the ink tank 310, the user accesses the ink tank 310 by rotating the lid 302 and opening it upward.

FIG. 4 is a diagram showing the configuration of the ink tank 310. The axes X, Y, and Z in FIG. 4 represent axes in a state where the electronic device 10 is used in a normal posture and the ink tank 310 is appropriately fixed to the case portion 301. Specifically, the X-axis and the Y-axis are axes along the horizontal direction, and the Z-axis is an axis along the vertical direction. Unless otherwise specified, the same applies to each axis of XYZ in the following drawings. The ink tank 310 is a three-dimensional object in which the ± X direction is the short side direction and the ± Y direction is the longitudinal direction. Hereinafter, among the surfaces of the ink tank 310, the surface in the + Z direction is referred to as the upper surface, the surface in the −Z direction is referred to as the bottom surface, and the surfaces in the ± X direction and the ± Y direction are referred to as side surfaces. The ink tank 310 is made of, for example, a synthetic resin such as nylon or polypropylene.

When the ink tank unit 300 includes a plurality of ink tanks 310 as described above, the plurality of ink tanks 310 may be formed separately or integrally. When the ink tanks 310 are integrally formed, the ink tanks 310 may be integrally molded, or a plurality of separately molded ink tanks 310 may be integrally bundled or connected.

The ink tank 310 includes an injection port 311 into which ink IK is injected by a user and an discharge port 312 in which ink IK is discharged toward the print head 107. In the present embodiment, the upper surface of the portion on the + Y direction side, which is the front of the ink tank 310, is higher than the upper surface of the portion on the −Y direction side, which is the rear surface. An injection port 311 for injecting ink IK from the outside is provided on the upper surface of the front portion of the ink tank 310. As described above with reference to FIG. 3, the injection port 311 is exposed by opening the lid 302 and the cap. By injecting ink IK from the injection port 311 by the user, the ink tank 310 can be replenished with ink IK of each color. The ink IK for the user to refill the ink tank 310 is stored and provided in a separate refill container. Further, an discharge port 312 for supplying ink to the print head 107 is provided on the upper surface of the rear portion of the ink tank 310. By providing the injection port 311 on the side close to the front surface of the electronic device 10, it is possible to facilitate the injection of ink IK.

1.4 Other Configurations of Electronic Devices FIG. 5 is a schematic configuration diagram of the electronic devices 10 according to the present embodiment. As shown in FIG. 5, the printer unit 100 according to the present embodiment includes a carriage 106, a paper feed motor 108, a carriage motor 109, a paper feed roller 110, a processing unit 120, a storage unit 140, and a display unit. It includes 150, an operation unit 160, and an external I / F unit 170. In FIG. 5, the specific configuration of the scanner unit 200 is omitted. Further, FIG. 5 is a diagram illustrating the connection relationship of each part of the printer unit 100 and the ink tank unit 300, and does not limit the physical structure and positional relationship of each part. For example, various embodiments can be considered for the arrangement of members such as the ink tank 310, the carriage 106, and the tube 105 in the electronic device 10.

A print head 107 is mounted on the carriage 106. The print head 107 has a plurality of nozzles that eject ink IK in the −Z direction on the bottom surface side of the carriage 106. A tube 105 is provided between the print head 107 and each ink tank 310. Each ink IK in the ink tank 310 is sent to the print head 107 via the tube 105. The print head 107 ejects each ink IK sent from the ink tank 310 to the print medium P from a plurality of nozzles as ink droplets.

The carriage 106 is driven by the carriage motor 109 to reciprocate on the print medium P along the main scanning axis HD. The paper feed motor 108 rotationally drives the paper feed roller 110 to convey the print medium P along the sub-scanning axis VD. The injection control of the print head 107 is performed by the processing unit 120 via a cable.

In the printer unit 100, under the control of the processing unit 120, the carriage 106 moves along the main scanning axis HD from the plurality of nozzles of the print head 107 with respect to the print medium P conveyed to the sub-scanning axis VD. Printing is performed on the print medium P by injecting the ink IK.

One end of the main scanning axis HD in the moving region of the carriage 106 is a home position region in which the carriage 106 stands by. In the home position region, for example, a cap (not shown) for performing maintenance such as cleaning the nozzle of the print head 107 is arranged. Further, in the moving area of the carriage 106, a waste ink box or the like for receiving waste ink when flushing or cleaning the print head 107 is arranged. Note that flushing refers to injecting ink IK from each nozzle of the print head 107 during printing on the print medium P, regardless of printing. Cleaning means cleaning the inside of the print head by sucking the print head with a pump or the like provided in the waste ink box without driving the print head 107.

Here, an off-carriage type printing device in which the ink tank 310 is provided at a position different from that of the carriage 106 is assumed. However, the printer unit 100 may be an on-carriage type printing device in which the ink tank 310 is mounted on the carriage 106 and moves along the main scanning axis HD together with the print head 107. The on-carriage type printing device will be described later with reference to FIG. 40.

An operation unit 160 and a display unit 150 as user interface units are connected to the processing unit 120. The display unit 150 is for displaying various display screens, and can be realized by, for example, a liquid crystal display or an organic EL display. The operation unit 160 is for the user to perform various operations, and can be realized by various buttons, GUI, and the like. For example, as shown in FIG. 1, the electronic device 10 includes an operation panel 101, and the operation panel 101 includes a display unit 150, a button which is an operation unit 160, and the like. Further, the display unit 150 and the operation unit 160 may be integrally configured by a touch panel. When the user operates the operation panel 101, the processing unit 120 operates the printer unit 100 and the scanner unit 200.

For example, in FIG. 1, after setting a document on the platen of the scanner unit 200, the user operates the operation panel 101 to start the operation of the electronic device 10. Then, the original is read by the scanner unit 200. Subsequently, the print medium P is fed from the paper cassette into the printer unit 100 based on the image data of the scanned document, and the printer unit 100 prints on the print medium P.

An external device can be connected to the processing unit 120 via the external I / F unit 170. The external device here is, for example, a PC (Personal Computer). The processing unit 120 receives image data from an external device via the external I / F unit 170, and controls the printer unit 100 to print the image on the print medium P. Further, the processing unit 120 controls to read the original by the scanner unit 200 and transmit the image data as the scanning result to the external device via the external I / F unit 170, or control to print the image data as the scanning result. I do.

The processing unit 120 performs, for example, drive control, consumption amount calculation processing, ink amount detection processing, and ink type determination processing. The processing unit 120 of this embodiment is composed of the following hardware. The hardware can include at least one of a circuit that processes a digital signal and a circuit that processes an analog signal. For example, hardware can be composed of one or more circuit devices mounted on a circuit board or one or more circuit elements. One or more circuit devices are, for example, ICs and the like. One or more circuit elements are, for example, resistors, capacitors, and the like.

Further, the processing unit 120 may be realized by the following processor. The electronic device 10 of the present embodiment includes a memory for storing information and a processor that operates based on the information stored in the memory. The information is, for example, a program and various data. The processor includes hardware. As the processor, various processors such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and a DSP (Digital Signal Processor) can be used. The memory may be a semiconductor memory such as SRAM (Static Random Access Memory) or DRAM (Dynamic Random Access Memory), a register, or a magnetic storage device such as a hard disk device. , An optical storage device such as an optical disk device may be used. For example, the memory stores instructions that can be read by a computer, and when the instructions are executed by the processor, the functions of each part of the electronic device 10 are realized as processing. The instruction here may be an instruction of an instruction set constituting a program, or an instruction instructing an operation to a hardware circuit of a processor.

The processing unit 120 controls the carriage motor 109 to perform drive control for moving the carriage 106. Based on the drive control, the carriage motor 109 drives the print head 107 provided on the carriage 106 to move.

Further, the processing unit 120 performs a consumption amount calculation process for calculating the amount of ink consumed by injecting ink IK from each nozzle of the print head 107. The processing unit 120 starts the consumption amount calculation process with the state in which the ink IK is filled in each ink tank 310 as an initial value. More specifically, when the user replenishes the ink tank 310 with ink IK and presses the reset button, the processing unit 120 initializes the ink consumption count value for the ink tank 310. Specifically, the count value of ink consumption is set to 0 g. Further, the processing unit 120 starts the consumption calculation process triggered by the operation of pressing the reset button.

Further, the processing unit 120 performs an ink amount detection process for detecting the amount of ink IK contained in the ink tank 310 based on the output of the sensor unit 320 provided corresponding to the ink tank 310. Further, the processing unit 120 performs an ink type determination process for determining the type of ink IK contained in the ink tank 310 based on the output of the sensor unit 320 provided corresponding to the ink tank 310. Details of the ink amount detection process and the ink type determination process will be described later.

1.5 Detailed configuration example of the sensor unit FIG. 6 is an exploded perspective view schematically showing the configuration of the sensor unit 320. The sensor unit 320 includes a substrate 321, a photoelectric conversion device 322, a light source 323, a light guide body 324, a lens array 325, and a case 326.

The light source 323 and the photoelectric conversion device 322 are mounted on the substrate 321. The photoelectric conversion device 322 is, for example, a linear image sensor in which photoelectric conversion elements are arranged side by side in a predetermined direction. The linear image sensor may be a sensor in which photoelectric conversion elements are arranged in a row, or a sensor in which photoelectric conversion elements are arranged in two or more rows. The photoelectric conversion element is, for example, PD (Photodiode). By using the linear image sensor, a plurality of output signals based on a plurality of photoelectric conversion elements are acquired. Therefore, it is possible to estimate not only the presence or absence of ink IK but also the position of the liquid level. The liquid level may be paraphrased as an interface.

The light source 323 has, for example, R, G, and B light emitting diodes (LEDs), and emits light in order while switching the R, G, and B light emitting diodes at high speed. Hereinafter, the light emitting diode of R is referred to as a red LED 323R, the light emitting diode of G is referred to as a green LED 323G, and the light emitting diode of B is referred to as a blue LED 323B. The light guide body 324 is a rod-shaped member for guiding light, and the cross-sectional shape may be a quadrangular shape, a circular shape, or another shape. The longitudinal direction of the light guide body 324 is a direction along the longitudinal direction of the photoelectric conversion device 322. Since the light from the light source 323 is emitted from the light guide body 324, if it is not necessary to distinguish between the light guide body 324 and the light source 323, the light guide body 324 and the light source 323 are used. Collectively referred to as a light source.

The light source 323, the light guide body 324, the lens array 325, and the photoelectric conversion device 322 are housed between the case 326 and the substrate 321. The case 326 is provided with a first opening 327 for a light source and a second opening 328 for a photoelectric conversion device. When the light emitted by the light source 323 is incident on the light guide body 324, the entire light guide body emits light. The light emitted from the light guide body 324 is irradiated to the outside of the case 326 through the first opening 327. Light from the outside is input to the lens array 325 through the second opening 328. The lens array 325 guides the input light to the photoelectric conversion device 322. Specifically, the lens array 325 is a SELFOCK lens array (SELFOC is a registered trademark) in which a large number of refractive index distribution type lenses are arranged.

FIG. 7 is a diagram schematically showing the arrangement of the photoelectric conversion device 322. As shown in FIG. 7, n (n is an integer of 1 or more) photoelectric conversion devices 322 are arranged side by side on the substrate 321 along a given direction. Here, as shown in FIG. 7, n may be 2 or more. That is, the sensor unit 320 includes a second linear image sensor provided on the longitudinal side of the linear image sensor. The linear image sensor here is, for example, 322-1 in FIG. 7, and the second linear image sensor is 322-2. As described above, each photoelectric conversion device 322 is a chip having a large number of photoelectric conversion elements arranged side by side. By using the plurality of photoelectric conversion devices 322, the range for detecting the incident light is widened, so that the target range for detecting the amount of ink can be widened. However, the number of linear image sensors, that is, the setting of the target range for ink amount detection can be variously modified, and it is not prevented that there is only one linear image sensor.

FIG. 8 is a cross-sectional view schematically showing the arrangement of the sensor unit 320. As can be seen from FIGS. 6 and 7, the positions of the photoelectric conversion device 322 and the light source 323 do not overlap on the Z axis, but for convenience of explaining the positional relationship with other members, the light source 323 is shown in FIG. There is. As shown in FIG. 8, the sensor unit 320 includes a light blocking wall 329 provided between the light source 323 and the photoelectric conversion device 322. The light blocking wall 329 is, for example, a part of the case 326, and is formed by extending a beam-shaped member between the first opening 327 and the second opening 328 to the substrate 321. The light blocking wall 329 blocks direct light from the light source 323 to the photoelectric conversion device 322. By providing the light blocking wall 329, the incidental light can be suppressed, so that the accuracy of detecting the amount of ink can be improved. The light blocking wall 329 may block direct light from the light source 323 to the photoelectric conversion device 322, and its specific shape is not limited to FIG. Further, a member different from the case 326 may be used as the light blocking wall 329.

FIG. 9 is a diagram illustrating the positional relationship between the ink tank 310 and the sensor unit 320. As shown in FIG. 9, the sensor unit 320 is fixed to any wall surface of the ink tank 310 in a posture in which the longitudinal direction of the photoelectric conversion device 322 is the ± Z direction. That is, the photoelectric conversion device 322, which is a linear image sensor, is provided so that the longitudinal direction is along the vertical direction. The vertical direction here represents the direction of gravity when the electronic device 10 is used in an appropriate posture, and the opposite direction.

In the example of FIG. 9, the sensor unit 320 is fixed to the side surface of the ink tank 310 in the −Y direction. That is, the substrate 321 on which the photoelectric conversion device 322 is provided is closer to the discharge port 312 than the injection port 311 of the ink tank 310. Whether or not printing can be executed in the printer unit 100 depends on whether or not the ink IK is supplied to the print head 107. Therefore, by providing the sensor unit 320 on the discharge port 312 side, it is possible to perform the ink amount detection process on the ink tank 310 at a position where the ink amount is particularly important.

As shown in FIG. 9, the ink tank 310 may include a main container 315, a second discharge port 313, and an ink flow path 314. The main container 315 is a portion of the ink tank 310 used for accommodating the ink IK. The second discharge port 313 is, for example, an opening provided at the most −Z direction position in the main container 315. However, various modifications can be made to the position and shape of the second discharge port 313. For example, when suction is performed by a suction pump or pressurized air is supplied to the ink tank 310 by a pressure pump, the ink IK accumulated in the main container 315 of the ink tank 310 is discharged to the second discharge port. It is discharged from 313. The ink IK discharged from the second discharge port 313 is guided in the + Z direction by the ink flow path 314, and is discharged from the discharge port 312 to the outside of the ink tank 310. At this time, as shown in FIG. 9, the ink flow path 314 and the photoelectric conversion device 322 are not opposed to each other, so that an appropriate amount of ink can be detected. For example, the ink flow path 314 is provided at the end of the ink tank 310 in the −X direction, and the sensor unit 320 is provided in the + X direction with respect to the ink flow path 314. By doing so, it is possible to prevent the ink in the ink flow path 314 from deteriorating the accuracy of the ink amount detection process.

As described above, the "discharge port" in the present embodiment is a discharge port 312 for discharging the ink IK to the outside of the ink tank 310, and a discharge port 312 for discharging the ink IK from the main container 315 to the discharge port 312. Includes a second outlet 313. Of these, the second discharge port 313 is more strongly related to whether or not the ink IK is supplied to the print head 107. As shown in FIG. 9, the substrate 321 on which the photoelectric conversion device 322 is provided is closer to the second discharge port 313 than the injection port 311 of the ink tank 310. This makes it possible to perform the ink amount detection process at a position where the ink amount is particularly important. However, as the distance between the discharge port 312 and the second discharge port 313 becomes longer, it is necessary to lengthen the ink flow path 314, which may complicate the arrangement of the ink flow path 314. That is, it is desirable that the discharge port 312 and the second discharge port 313 are provided at close positions. Therefore, as described above, by providing the substrate 321 at a position closer to the discharge port 312 than the injection port 311 it is possible to perform the ink amount detection process targeting the position where the ink amount is important. The same applies to the following description, and in the expression that the given member is "closer to the injection port 311 than the discharge port 312 of the ink tank 310" or a similar expression, the discharge port 312 is appropriately referred to as the second discharge port 312. It can be replaced with the exit 313.

The sensor unit 320 may be adhered to, for example, the ink tank 310. Alternatively, the sensor unit 320 may be attached to the ink tank 310 by providing fixing members to the sensor unit 320 and the ink tank 310, respectively, and fixing the members to each other by fitting or the like. Various modifications can be made to the shape, material, etc. of the fixing member. Further, as will be described later with reference to FIGS. 38 to 40, the sensor unit 320 may be configured to be relatively movable with respect to the ink tank 310.

The photoelectric conversion device 322 is provided in the range of z1 to z2, for example, on the Z axis. z1 and z2 are coordinate values on the Z axis, and z1 <z2. When the light from the light source 323 is applied to the ink tank 310, the ink IK filled in the ink tank 310 causes light absorption and scattering. Therefore, in the ink tank 310, the portion not filled with the ink IK becomes relatively bright, and the portion filled with the ink IK becomes relatively dark. For example, when the liquid level of the ink IK exists at the position where the coordinate value on the Z axis is z0, the region of the ink tank 310 whose Z coordinate value is z0 or less becomes dark and the region larger than z0 becomes bright.

As shown in FIG. 9, by providing the photoelectric conversion device 322 so that the longitudinal direction is the vertical direction, the position of the liquid surface of the ink IK can be appropriately detected. Specifically, if z1 <z0 <z2, among the photoelectric conversion devices 322, the photoelectric conversion element arranged at the position corresponding to the range of z1 to z0 receives a relatively small amount of light, so that the amount of light input is relatively small. The output value becomes relatively small. Since the photoelectric conversion element arranged at the position corresponding to the range of z0 to z2 receives a relatively large amount of light, the output value becomes relatively large. That is, it is possible to estimate z0, which is the liquid level of the ink IK, based on the output of the photoelectric conversion device 322. That is, it is possible to detect not only binary information as to whether or not the amount of ink is equal to or greater than a predetermined amount, but also a specific liquid level position. If the position of the liquid level is known, it is possible to determine the amount of ink in units of milliliters or the like based on the shape of the ink tank 310. Further, when the output value of the entire range of z1 to z2 is large, it is determined that the liquid level is lower than z1, and when the output value of the entire range of z1 to z2 is small, it is determined that the liquid level is higher than z2. Is also possible. Further, the range in which the amount of ink can be detected is the range of z1 to z2 in which the photoelectric conversion device 322 is provided. Therefore, the detection range can be easily adjusted by changing the number of photoelectric conversion devices 322 and the length per chip. Further, the resolution of ink amount detection is determined based on the pixel pitch of the photoelectric conversion device 322 and the pitch of the lens array 325. In the example described later with reference to FIG. 15, the ink amount detection is performed at a resolution corresponding to k times the pixel pitch. Although various modifications can be made to the specific resolution, according to the method of the present embodiment, it is possible to realize highly accurate ink amount detection as compared with the conventional method.

Considering that the amount of ink is detected accurately, it is preferable that the light emitted to the ink tank 310 is about the same regardless of the position in the vertical direction. As described above, the presence or absence of ink IK appears as a difference in brightness, and if the amount of irradiation light varies, the accuracy will decrease. Therefore, the sensor unit 320 has a light guide body 324 arranged so that the longitudinal direction is the vertical direction. The light guide body 324 here is a rod-shaped light guide as described above. Considering that the light guide body 324 is uniformly illuminated, it is preferable that the light source 323 injects light into the light guide body 324 from a lateral direction, that is, a direction along the longitudinal direction of the light guide body 324. In this way, the incident angle becomes large, so that total reflection is likely to occur.

10 to 12 are views for explaining the positional relationship between the light source 323 and the light guide body 324. For example, as shown in FIG. 10, the light source 323 and the light guide body 324 may be provided so as to be aligned with each other on the Z axis. By irradiating the light source 323 with light in the + Z direction, it becomes possible to guide the light in the longitudinal direction of the light guide body 324. Alternatively, as shown in FIG. 11, the end portion of the light guide body 324 on the light source side may be bent. In this way, the light source 323 can guide the light in the longitudinal direction of the light guide body 324 by irradiating the light in the direction perpendicular to the substrate 321. Alternatively, as shown in FIG. 12, a reflecting surface RS may be provided at the end of the light guide body 324 on the light source side. The light source 323 irradiates light in a direction perpendicular to the substrate 321. The light from the light source 323 is guided in the longitudinal direction of the light guide body 324 by being reflected by the reflecting surface RS. The light guide 324 in the present embodiment widely applies a known configuration, such as providing a reflector on the surface of the light guide 324 in the −Y direction and changing the density of the reflector according to the position from the light source 323. It is possible. Further, the light source 323 may be provided in the + Z direction with respect to the light guide body 324, or the light source 323 of the same color may be provided at both ends of the light guide body 324, and the configurations of the light source 323 and the light guide body 324 are various. Can be modified.

It is desirable that at least the portion of the inner wall of the ink tank 310 facing the photoelectric conversion device 322 has higher ink repellency than the outer wall of the ink tank 310. Of course, the entire inner wall of the ink tank 310 may be processed so that the ink repellency is higher than that of the outer wall of the ink tank 310. The portion facing the photoelectric conversion device 322 may be the entire inner wall of the ink tank 310 in the −Y direction, or may be a part of the inner wall. The part of the inner wall is specifically a region of the inner wall of the ink tank 310 in the −Y direction including a portion whose position on the XZ plane overlaps with the photoelectric conversion device 322. When ink droplets adhere to the inner wall of the ink tank 310, the portion of the ink droplets becomes darker than the portion where the ink does not exist. Therefore, the accuracy of detecting the amount of ink may decrease due to the ink droplets. By increasing the ink repellency of the inner wall of the ink tank 310, it is possible to suppress the adhesion of ink droplets.

1.6 Detailed configuration example of the sensor unit and the processing unit FIG. 13 is a functional block diagram of the sensor unit 320. The electronic device 10 includes a processing unit 120 and an AFE (Analog Front End) circuit 130. In this embodiment, the photoelectric conversion device 322 and the AFE circuit 130 are referred to as a sensor 190. The processing unit 120 is provided on the second substrate 111. The processing unit 120 corresponds to the processing unit 120 shown in FIG. 5 and outputs a control signal for controlling the photoelectric conversion device 322. The control signal includes a clock signal CLK and a chip enable signal EN1 described later. The AFE circuit 130 is a circuit having at least a function of A / D converting an analog signal from the photoelectric conversion device 322. The second substrate 111 is, for example, the main substrate of the electronic device 10, and the substrate 321 described above is a sub substrate for the sensor unit.

In FIG. 13, the sensor unit 320 includes a red LED 323R, a green LED 323G, a blue LED 323B, and n photoelectric conversion devices 322. As mentioned above, n is an integer greater than or equal to 1. The red LED 323R, the green LED 323G, and the blue LED 323B are provided in the light source 323, and the plurality of photoelectric conversion devices 322 are arranged side by side on the substrate 321. A plurality of red LED 323R, green LED 323G, and blue LED 323B may be present.

The AFE circuit 130 is realized by, for example, an integrated circuit (IC). The AFE circuit 130 includes a non-volatile memory (not shown). The non-volatile memory here is, for example, SRAM. The AFE circuit 130 may be provided on the substrate 321 or may be provided on a substrate different from the substrate 321.

The processing unit 120 controls the operation of the sensor unit 320. First, the processing unit 120 controls the operations of the red LED 323R, the green LED 323G, and the blue LED 323B. Specifically, the processing unit 120 supplies the drive signal DrvR to the red LED 323R for a certain exposure time Δt at a constant cycle T to cause the red LED 323R to emit light. Similarly, the processing unit 120 supplies the green LED 323G with the drive signal DrvG for the exposure time Δt in the cycle T to emit the green LED 323G, and supplies the drive signal DrvB to the blue LED 323B for the exposure time Δt in the cycle T. Then, the blue LED 323B is made to emit light. The processing unit 120 causes the red LED 323R, the green LED 323G, and the blue LED 323B to emit light exclusively one by one in order during the cycle T.

Further, the processing unit 120 controls the operation of n photoelectric conversion devices 323 (322-13-22-n). Specifically, the processing unit 120 commonly supplies the clock signal CLK to the n photoelectric conversion devices 322. The clock signal CLK is an operating clock signal of the n photoelectric conversion devices 322, and each of the n photoelectric conversion devices 322 operates based on the clock signal CLK.

When each photoelectric conversion device 322-j (j = 1 to n) receives the chip enable signal ENj after each photoelectric conversion element receives light, each photoelectric conversion element receives the light in synchronization with the clock signal CLK. The output signal OS is generated and output based on the light.

The processing unit 120 generates a chip enable signal EN1 that is active only for a time until the photoelectric conversion device 322-1 ends the output of the output signal OS after emitting the red LED 323R, the green LED 323G, or the blue LED 323B, and the photoelectric conversion device 120 generates a photoelectric It is supplied to the conversion device 322-1.

The photoelectric conversion device 322-j generates a chip enable signal ENj + 1 before ending the output of the output signal OS. Then, the chip enable signals EN2 to ENn are supplied to the photoelectric conversion devices 322 to 322-n, respectively.

As a result, after the red LED 323R, the green LED 323G, or the blue LED 323B emits light, the n photoelectric conversion devices 322 output the output signal OS in order. Then, the sensor unit 320 outputs the output signal OS sequentially output by the n photoelectric conversion devices 322 from terminals (not shown). The output signal OS is transferred to the AFE circuit 130.

The AFE circuit 130 sequentially receives output signal OSs that are sequentially output from n photoelectric conversion devices 322, performs amplification processing and A / D conversion processing on each output signal OS, and performs amplification processing and A / D conversion processing on each output signal OS of each photoelectric conversion element. It is converted into digital data including a digital value according to the amount of received light, and each digital data is sequentially transmitted to the processing unit 120. The processing unit 120 receives each digital data sequentially transmitted from the AFE circuit 130, and performs an ink amount detection process and an ink type determination process, which will be described later.

FIG. 14 is a functional block diagram of the photoelectric conversion device 322. The photoelectric conversion device 322 includes a control circuit 3222, a booster circuit 3223, a pixel drive circuit 3224, p pixel units 3225, a CDS (Correlated Double Sampling) circuit 3226, a sample hold circuit 3227, and an output circuit 3228. The configuration of the photoelectric conversion device 322 is not limited to FIG. 14, and it is possible to carry out modifications such as omitting a part of the configuration. For example, the CDS circuit 3226, the sample hold circuit 3227, and the output circuit 3228 may be omitted, and corresponding processing such as noise reduction processing and amplification processing may be performed in the AFE circuit 130.

In the photoelectric conversion device 322, the power supply voltage VDD and the power supply voltage VSS are supplied from the two power supply terminals VDP and VSS, respectively. Further, the photoelectric conversion device 322 operates based on the chip enable signal EN_I, the clock signal CLK, and the reference voltage VREF supplied from the reference voltage supply terminal VRP. The power supply voltage VDD corresponds to the high potential side power supply, and is, for example, 3.3 V. VSS corresponds to the low potential side power supply, for example, 0V. The chip enable signal EN_I is one of the chip enable signals EN1 to ENn in FIG.

The chip enable signal EN_I and the clock signal CLK are input to the control circuit 3222. The control circuit 3222 controls the operations of the booster circuit 3223, the pixel drive circuit 3224, the p pixel units 3225, the CDS circuit 3226, and the sample hold circuit 3227 based on the chip enable signal EN_I and the clock signal CLK. Specifically, the control circuit 3222 includes a control signal CPC that controls the booster circuit 3223, a control signal DRC that controls the pixel drive circuit 3224, a control signal CDSC that controls the CDS circuit 3226, and a sampling signal that controls the sample hold circuit 3227. The SMP, the pixel selection signal SEL0 that controls the pixel unit 3225, the reset signal RST, and the chip enable signal EN_O are generated.

The booster circuit 3223 boosts the power supply voltage VDD based on the control signal CPC from the control circuit 3222, and generates a transfer control signal Tx having the boosted power supply voltage as a high level. The transfer control signal Tx is a control signal for transferring the electric charge generated based on the photoelectric conversion by the photoelectric conversion element during the exposure time Δt, and is commonly supplied to the p pixel units 3225.

The pixel drive circuit 3224 generates a drive signal Drv that drives p pixel units 3225 based on the control signal DRC from the control circuit 3222. The p pixel units 3225 are provided side by side in the one-dimensional direction, and the drive signal Drv is transferred to the p pixel units 3225. Then, when the drive signal Drv is active and the pixel selection signal SELi-1 is active, the i-th pixel unit 3225 (i is any of 1 to p) activates the pixel selection signal SELi to generate a signal. Output. The pixel selection signal SELi is output to the i + 1th pixel unit 3225.

The p pixel units 3225 include a photoelectric conversion element that receives light and performs photoelectric conversion, and each includes a transfer control signal Tx, a pixel selection signal SEL (any of SEL0 to SELp-1), a reset signal RST, and a drive signal Drv. Based on the above, the photoelectric conversion element outputs a signal having a voltage corresponding to the light received during the exposure time Δt. The signals output from the p pixel units 3225 are sequentially transferred to the CDS circuit 3226.

The CDS circuit 3226 is input with a signal Vo including signals output from each of the p pixel units 3225 in order, and operates based on the control signal CDSC from the control circuit 3222. The CDS circuit 3226 removes noise generated by variation in the characteristics of the amplification transistors of the p pixel units 3225 and superimposed on the signal Vo by correlated double sampling with reference to the reference voltage VREF. That is, the CDS circuit 3226 is a noise reduction circuit that reduces noise included in the signal output from the p pixel units 3225.

The sample hold circuit 3227 samples the signal from which noise has been removed by the CDS circuit 3226 based on the sampling signal SMP, holds the sampled signal, and outputs the sampled signal to the output circuit 3228.

The output circuit 3228 amplifies the signal output by the sample hold circuit 3227 to generate an output signal OS. As described above, the output signal OS is output from the photoelectric conversion device 322 via the output terminal OP1 and supplied to the AFE circuit 130.

The control circuit 3222 generates a chip enable signal EN_O, which is a high pulse signal, shortly before the output of the output signal OS from the output circuit 3228 ends, and outputs the chip enable signal EN_O from the output terminal OP2 to the photoelectric conversion device 322 in the next stage. The chip enable signal EN_O here is one of the chip enable signals EN2 to ENn + 1 in FIG. After that, the control circuit 3222 stops the output of the output signal OS in the output circuit 3228, and further sets the output terminal OP1 to high impedance.

As described above, the sensor 190 of the present embodiment includes the photoelectric conversion device 322 and the AFE circuit 130 connected to the photoelectric conversion device 322. In this way, it is possible to output appropriate pixel data based on the output signal OS output from the photoelectric conversion device 322. The output signal OS is an analog signal, and the pixel data is digital data. The sensor 190 may output a number of pixel data corresponding to the number of photoelectric conversion elements included in the photoelectric conversion device 322, but the sensor 190 is not limited to this. As will be described later with reference to FIG. 16, the photoelectric conversion device 322 may generate an output signal OS representing the total output of a plurality of pixels. Alternatively, as will be described later with reference to FIG. 20 and the like, in the AFE circuit 130, a part of the outputs of the plurality of pixels may be thinned out, or information corresponding to the total output of the plurality of pixels may be calculated. Good.

2. Lens Pitch and Pixel Pitch As described above, the sensor unit 320 of the present embodiment includes a lens array 325 in which a plurality of selfock lenses are arranged side by side in a predetermined direction. The photoelectric conversion element included in the photoelectric conversion device 322 receives light from the lens array 325 and outputs a signal corresponding to the amount of light.

FIG. 15 is a diagram showing the relationship between a plurality of selfock lenses and a plurality of photoelectric conversion elements arranged in the ± Z direction and the amount of light after passing through the lens array 325. One selfock lens has a light amount distribution in which the amount of light is large in the direction along the optical axis and the amount of light decreases as the distance from the optical axis increases. The optical axis here is, for example, an axis that passes through the center of the selfock lens and is parallel to the Y axis. In a Selfoc lens array, the image produced by a given Selfoc lens overlaps the image produced by a nearby Selfoc lens. Since the amount of light of the Selfock lens array is the sum of the amount of light of each Selfock lens, the amount of light has periodic unevenness corresponding to the pitch of the lens, as shown in FIG. For example, even when a uniform amount of light is incident on the lens array 325, the amount of light transmitted through the lens array 325 changes periodically in the ± Z direction.

In the present embodiment, the ink amount detection process and the ink type determination process are performed based on the amount of light detected by the photoelectric conversion device 322 as described later. Light intensity unevenness is a factor that reduces the accuracy of these processes. Specifically, due to the unevenness of the amount of light, there is a possibility that an erroneous determination may occur in the comparison process with the threshold value described later.

When the lens array 325 and the photoelectric conversion device 322 are used in the scanner, shading correction is performed. Since the reference value in the shading correction is information including the light amount unevenness, the light amount unevenness can be reduced by performing the shading correction using the reference value. Also in this embodiment, shading correction is not hindered. However, in order to perform shading correction, it is necessary to measure the reference value in advance and write it to the non-volatile memory. Therefore, the number of processes before shipping increases, which leads to an increase in cost. Further, the processing unit 120 needs to perform an ink amount detection process or the like after performing a correction process using the reference value on the pixel data output from the sensor 190. Therefore, the processing load during operation of the printing apparatus is also large.

Therefore, in the present embodiment, the pitch of the plurality of lenses may be k times the pixel pitch of the sensor 190 (k is an integer of 2 or more). The lens pitch is the lens arrangement interval included in the lens array 325. Specifically, the lens pitch is the distance from the reference position of a given lens to the reference position of adjacent lenses. The reference position here may be the center of the lens, one end point on the Z axis, or the other position. As shown in FIG. 15, when it is considered that the lenses are arranged without gaps, the pitch of the lenses corresponds to the length of one lens on the Z axis, specifically, the diameter. The pixel pitch of the sensor 190 is the arrangement interval of the photoelectric conversion elements included in the photoelectric conversion device 322. Specifically, the pixel pitch is the distance from the reference position of a given photoelectric conversion element to the reference position of adjacent photoelectric conversion elements.

Then, the processing unit 120 determines the amount of ink based on the total output of k consecutive pixels. The pixel here corresponds to the pixel portion 3225 of FIG. 14, and represents the output of the smallest unit in the photoelectric conversion device 322. Specifically, one pixel corresponds to one photoelectric conversion element.

As described above, the light intensity unevenness of the lens array 325 has a periodicity corresponding to the pitch of the lens. By setting the pitch of the lens to k times the pixel pitch, k consecutive pixels have a length corresponding to the wavelength of light intensity unevenness. Therefore, unevenness in the amount of light can be reduced by summing the outputs of continuous k pixels. For example, the degree of occurrence of light amount unevenness in the three pixels shown in A1 of FIG. 15 and the degree of occurrence of light amount unevenness in the three pixels shown in A2 are equivalent. Therefore, when the outputs of the three pixels shown in A1 and the three pixels shown in A2 are totaled, the difference due to the uneven light intensity is sufficiently reduced between the two totals. The same applies to the total output of the three pixels shown in A3 and A4. The information used by the processing unit 120 may be information based on the total output of continuous k pixels, and is not limited to the total itself. For example, the processing unit 120 may determine the amount of ink by using the average of the outputs of continuous k pixels. In a broad sense, the processing unit 120 may determine the amount of ink based on the information obtained by multiplying the total output of k pixels by a constant. The constant here is not limited to 1 / k, and information other than the average based on the sum may be used.

Here, the pitch of the lens is, for example, 300 micrometers. 300 micrometers is a widely used pitch in Selfoc lens arrays. For example, a Selfoc lens array widely used in scanners can be applied to the method of this embodiment.

Further, k may be 3 or more and 5 or less. Various designs are possible for the size of the photoelectric conversion element. However, it is not easy to manufacture an excessively large element. Further, in the ink amount detection process and the like in the present embodiment, an extremely high resolution is not required. For example, a scanner may use a resolution of 600 dpi (dots per inch), 1200 dpi, 4800 dpi, or the like, but the resolution of the present embodiment may be lower than this. For example, by using a pixel pitch photoelectric conversion device 322 used in a low-resolution scanner of about 250 to 430 dpi, it is possible to reduce costs while diverting parts. When the pitch of the lens is 300 micrometers, the pixel pitch is about 60 to 100 micrometers. Hereinafter, an example of k = 3 will be described.

The sensor 190 may output pixel data in units of one pixel to the processing unit 120, and the processing unit 120 may perform processing for obtaining the total or average of the pixel data for k consecutive pixels. In this case as well, it is possible to reduce the unevenness of the amount of light.

Alternatively, the sensor 190 may output pixel data corresponding to the total output of continuous k pixels. In this way, the sensor 190 performs a process of obtaining the total or average of the pixel data. Compared with the case where the processing unit 120 obtains the total or the average, the amount of data stored in the SRAM in the AFE circuit 130 can be reduced, and the amount of communication data between the AFE circuit 130 and the processing unit 120 can be reduced. It will be possible. The details of the amount of data will be described later with reference to FIGS. 19 to 26.

FIG. 16 is a diagram showing the configuration of the photoelectric conversion device 322. The same configuration as in FIG. 14 is omitted as appropriate. As shown in FIG. 16, each pixel unit 3225 is connected to the output terminal OP1 via a switch. As shown in FIG. 14, a CDS circuit 3226 or the like may be provided between the output terminal OP1 and the pixel unit 3225. Here, since nine pixel portions are illustrated, switches SW0 to SW8 are described. Each switch is realized by, for example, a transistor. The on / off of the switch is controlled by the control circuit 3222 based on the instruction from the processing unit 120.

The control circuit 3222 turns on the switches SW0, SW1 and SW2 and turns off the other switches during the period when the first to third pixel units 3225 of the p pixel units 3225 output a signal. In this case, an analog signal corresponding to the total of the three pixel units 3225 is output from the output terminal OP1. By performing A / D conversion processing on the signal in the AFE circuit 130, pixel data corresponding to the total output of three consecutive pixels is output. The pixel unit 3225 may include an amplifier. In this case, by adjusting the gain of the amplifier in advance, it is possible to output the total of three pixels, or it is possible to output the average of three pixels. Alternatively, the gain of the amplifier included in the AFE circuit 130 may be adjusted.

Similarly, during the period when the 4th to 6th pixel units 3225 output a signal, the switches SW3, SW4 and SW5 are turned on and the other switches are turned off to add up the next three consecutive pixels. Is output. The same applies thereafter, and the sensor 190 can output pixel data corresponding to the total output of continuous k pixels by controlling the k switches to be turned on in sequence. In this case, the output signal OS output from one photoelectric device 323 is a signal including p / k signals in order.

The photoelectric conversion device 322 may output pixel data in units of one pixel to the AFE circuit 130, and the AFE circuit 130 may perform a process of obtaining the total or average of the pixel data for k consecutive pixels.

Further, the sensor 190 may be capable of switching between an output in units of one pixel and an output in units of k pixels. For example, the processing unit 120 gives an output instruction in units of one pixel or an output instruction in units of k pixels to the sensor 190. When the output instruction in units of one pixel is received, the control circuit 3222 of the photoelectric conversion device 322 turns on the switches provided corresponding to the pixel unit 3225 one by one. Specifically, only the switch corresponding to the active pixel unit 3225 is turned on, and the other switches are turned off. When the output instruction in units of k pixels is received, the control circuit 3222 of the photoelectric conversion device 322 turns on the switches provided corresponding to the pixel unit 3225 in k sets as described above. In this way, it is possible to switch whether or not the sensor 190 corrects the light intensity unevenness. For example, when reducing the processing load in the processing unit 120, the output of k pixels is totaled in the sensor 190. On the other hand, when importance is attached to accuracy, the sensor 190 outputs pixel data in units of one pixel, and the processing unit 120 performs shading correction.

The lens pitch is, for example, 300 micrometers, the pixel pitch is, for example, 100 micrometers, and k = 3. However, since a manufacturing error occurs in the lens pitch and the pixel pitch, the lens pitch may not be an integral multiple of the pixel pitch. As described above, when the light amount unevenness is strictly corrected, it is desirable that the pitch of the lens and the k times of the pixel pitch are matched. This is because the continuous k pixels correspond to the wavelengths of uneven light intensity. However, it was confirmed that by using the pixel data corresponding to the total of a plurality of continuous pixels, it is possible to reduce the light amount unevenness to the extent that there is no problem in the ink amount detection process. Therefore, "the lens pitch is k times the pixel pitch" in the present embodiment may be designed so that the lens pitch is k times or substantially k times the pixel pitch, and the actual pitch ratio is an integer. It is not limited to doubling. For example, the lens pitch, pixel pitch, and k in this embodiment each have one significant digit.

In other words, the processing unit 120 determines the amount of ink based on the total output of k consecutive pixels provided in the sensor 190 corresponding to each lens of the plurality of lenses. That is, the lens and the continuous k pixel need only have a corresponding relationship, and do not have to be exactly the same.

For example, the pitch of the lens may be 300 ± 40 micrometers. In the present embodiment, even when an error of about 10% occurs in the lens pitch, the pixel pitch, or the relative relationship between the two pitches, the ink amount detection process can be performed with sufficient accuracy. It has been confirmed that.

3. 3. Ink amount detection process Next, a process of determining the amount of ink IK contained in the ink tank 310 based on the output of the sensor 190 will be described.

3.1 Basic ink amount detection process FIG. 17 is a waveform representing pixel data output from the sensor 190. As described above with reference to FIG. 13, the output signal OS of the photoelectric conversion device 322 is an analog signal, and pixel data, which is digital data, is acquired by A / D conversion by the AFE circuit 130.

The horizontal axis of FIG. 17 represents the position of the photoelectric conversion device 322 in the longitudinal direction, and the vertical axis represents the value of pixel data corresponding to the photoelectric conversion element provided at the position. The numerical values on the horizontal axis of FIG. 17 represent the distance from the reference position in millimeters. FIG. 17 shows an example in which a red LED 323R, a green LED 323G, and a blue LED 323B are provided as the light source 323. The processing unit 120 acquires three RGB pixel data as pixel data of the photoelectric conversion device 322.

When the longitudinal direction of the photoelectric conversion device 322 is the vertical direction, the left direction of the horizontal axis corresponds to the −Z direction and the right direction corresponds to the + Z direction. If the positional relationship between the photoelectric conversion device 322 and the ink tank 310 is known, it is possible to associate each photoelectric conversion element with the distance from the reference position of the ink tank 310. The reference position of the ink tank 310 is, for example, a position corresponding to the inner bottom surface of the ink tank 310. The inner bottom surface is the position of the lowest expected ink liquid level.

Further, the pixel data corresponding to one photoelectric conversion element is, for example, 8-bit data, and has a value in the range of 0 to 255. However, the value on the vertical axis can be replaced with the data after normalization processing or the like. Of course, the bit is not limited to 8 bits, and other bits such as 4 bits and 12 bits may be used.

As described above, the photoelectric conversion element corresponding to the region where the ink IK does not exist has a relatively large amount of light received, and the photoelectric conversion element corresponding to the region where the ink IK exists has a relatively small amount of light received. In the example of FIG. 17, the value of the output data is large in the range shown in D1, and the value of the output data is small in the range shown in D3. Then, in the range shown in D2 between D1 and D3, the value of the pixel data changes significantly with respect to the change in position. That is, the range of D1 is an ink non-detection region with a high probability that ink IK does not exist. The range of D3 is an ink detection region where there is a high probability that ink IK is present. The range of D2 is an ink boundary region representing the boundary between the region where the ink IK exists and the region where the ink IK does not exist.

The processing unit 120 performs ink amount detection processing based on the pixel data output by the sensor 190. Specifically, the processing unit 120 detects the position of the liquid surface of the ink IK based on the pixel data. As shown in FIG. 17, it is considered that the liquid level of the ink IK exists at any position in the boundary region D2. Therefore, the processing unit 120 detects the liquid level of the ink IK based on a given threshold value Th that is smaller than the value of the pixel data in the ink non-detection region and larger than the value of the pixel data in the ink detection region.

For example, the processing unit 120 specifies the maximum value of the pixel data as the value of the pixel data in the ink non-detection region. Then, the processing unit 120 determines a value smaller than the specified value by a predetermined amount as the threshold value Th. Alternatively, the processing unit 120 specifies the minimum value of the pixel data as the value of the pixel data in the ink detection region. Then, the processing unit 120 determines a value that is larger than the specified value by a predetermined amount as the threshold value Th. Alternatively, the processing unit 120 may determine the threshold value Th based on the average of the maximum value and the minimum value of the pixel data.

However, once the type of ink IK and the type of light source 323 are determined, it is possible to determine in advance the value of the pixel data corresponding to the ink liquid level. Therefore, the processing unit 120 may perform a process of reading a predetermined threshold value Th from the storage unit 140 instead of obtaining the threshold value Th each time.

When the threshold value Th is acquired, the processing unit 120 detects the position where the output value becomes Th as the liquid level position of the ink IK. In this way, the amount of ink contained in the ink tank 310 can be detected by using the photoelectric conversion device 322 which is a linear image sensor. The information directly obtained using Th is the relative position of the ink liquid level with respect to the photoelectric conversion device 322. Therefore, the processing unit 120 may perform a calculation for obtaining the remaining amount of ink IK based on the position of the liquid surface.

Further, when all the output data is larger than Th, the processing unit 120 does not have ink in the target range of ink amount detection, that is, the liquid level is further lower than the end point in the −Z direction of the photoelectric conversion device 322. Is determined. Further, when all the output data is smaller than Th, the processing unit 120 is filled with ink in the target range of ink amount detection, that is, the liquid level is at a position higher than the end point in the + Z direction of the photoelectric conversion device 322. Judge that there is. If it is impossible that the liquid level is higher than the end point in the + Z direction of the photoelectric conversion device 322, it may be determined that an abnormality has occurred.

The ink amount detection process is not limited to the process using the threshold value Th in FIG. For example, the processing unit 120 performs a process of obtaining the slope of the graph shown in FIG. The slope is specifically a differential value, and more specifically is a difference value of adjacent pixel data. Then, the processing unit 120 detects a point where the inclination is larger than the predetermined threshold value, more specifically, a position where the inclination is maximum as the position of the liquid surface. When the maximum value of the obtained inclination is equal to or less than a given inclination threshold value, the processing unit 120 raises the liquid level to a position lower than the end point in the −Z direction of the photoelectric conversion device 322 or from the end point in the + Z direction. It is determined that the position is higher. Which side the liquid level is on can be identified from the value of the pixel data.

When a plurality of pixel data are acquired based on a plurality of lights having different wavelength bands as shown in FIG. 17, the ink amount detection process may be performed based on any one pixel data. Alternatively, the processing unit 120 may specify the position of each pixel using each output data, and determine the final position of the liquid level based on the specified position. For example, the processing unit 120 has a liquid level position obtained based on the pixel data of R, a liquid level position obtained based on the pixel data of G, and a liquid level position obtained based on the pixel data of B. The average value of, etc. is determined as the liquid level position. Alternatively, the processing unit 120 may obtain the composite data obtained by synthesizing the three pixel data of RGB, and may obtain the position of the liquid surface based on the composite data. The composite data is, for example, average data obtained by averaging RGB pixel data at each point.

FIG. 18 is a flowchart illustrating a process including an ink amount detection process. When this process is started, the process unit 120 controls the light source 323 to emit light (S101). Then, during the period when the light source 323 emits light, a reading process using the photoelectric conversion device 322 is performed (S102). When the light source 323 includes a plurality of LEDs, the processing unit 120 sequentially executes the processes of S101 and S102 for each of the red LED 323R, the green LED 323G, and the blue LED 323B. By the above processing, the three RGB pixel data shown in FIG. 17 are acquired.

Next, the processing unit 120 performs an ink amount detection process based on the acquired pixel data (S103). As described above, the specific processing of S103 can be various modifications such as comparison processing with the threshold value Th and detection processing of the maximum value of the slope.

The processing unit 120 determines the amount of ink IK filled in the ink tank 310 based on the detected position of the liquid level (S104). For example, the processing unit 120 sets in advance three levels of ink amount, "large remaining amount", "low remaining amount", and "ink end", and determines which of the three levels of the current ink amount corresponds to. .. The large remaining amount means that a sufficient amount of ink IK remains and no user action is required to continue printing. The low remaining amount means that printing can be continued, but the amount of ink is low and it is desirable for the user to replenish the ink. The ink end represents a situation in which the amount of ink is significantly reduced and the printing operation should be stopped.

When it is determined in the processing of S104 that the remaining amount is large (S105), the processing unit 120 ends the processing without performing notification or the like. When it is determined in the process of S104 that the remaining amount is low (S106), the processing unit 120 performs a notification process for prompting the user to replenish the ink IK (S107). The notification process is performed, for example, by displaying a text or an image on the display unit 150. However, the notification process is not limited to the display, and may be a notification by causing a light emitting unit for notification to emit light, a notification by sound using a speaker, or a combination of these. You may. When the ink end is determined in the processing of S104 (S108), the processing unit 120 performs a notification process for prompting the user to replenish the ink IK (S109). The notification process of S109 may have the same contents as the notification process of S107. However, as described above, it is difficult for the ink end to continue the printing operation, and the ink end is in a more serious state than the remaining amount is small. Therefore, the processing unit 120 may perform a notification process different from that of S107 in S109. Specifically, the processing unit 120 changes the displayed text to a content that strongly prompts the user to replenish the ink IK, increases the frequency of light emission, makes the sound louder, and the like, as compared with the processing of S107. May be executed in S109. Further, the processing unit 120 may perform a process (not shown) such as stop control of the printing operation after the process of S109.

The execution trigger of the ink amount detection process shown in FIG. 18 can be set in various ways. For example, the start of execution of a given print job may be used as an execution trigger, or the elapse of a predetermined time may be used as an execution trigger.

Further, the processing unit 120 may store the amount of ink detected by the ink amount detection process in the storage unit 140. Then, the processing unit 120 performs processing based on the time-series change of the detected ink amount. For example, the processing unit 120 obtains an ink increase amount or an ink decrease amount based on the difference between the ink amount detected at a given timing and the ink amount detected at a timing earlier than that.

Since the ink IK is used for printing, head cleaning, and the like, it is natural for the electronic device 10 to reduce the amount of ink. However, the amount of ink IK consumed per unit time in printing and the amount of ink IK consumed per head cleaning are fixed to some extent, and if the consumption is extremely large, some abnormality such as ink leakage will occur. There is a possibility that it is.

For example, the processing unit 120 obtains in advance the standard ink consumption expected in printing or the like. The standard ink consumption may be determined based on the estimated ink consumption per unit time, or may be determined based on the estimated ink consumption per job. The processing unit 120 determines that an abnormality occurs when the ink reduction amount obtained based on the time-series ink amount detection processing is larger than a predetermined amount by a predetermined amount or more with respect to the standard ink consumption amount. Alternatively, the processing unit 120 may perform a consumption amount calculation process for calculating the ink consumption amount by counting the number of times the ink IK is ejected. In this case, the processing unit 120 determines that the abnormality is determined when the ink reduction amount obtained based on the time-series ink amount detection process is larger than the ink consumption amount calculated by the consumption amount calculation process by a predetermined amount or more. ..

The processing unit 120 sets the abnormality flag to ON when it is determined that there is an abnormality. In this way, it is possible to execute some kind of error processing when the amount of ink is excessively reduced. Various processes can be considered when the abnormality flag is set to ON. For example, the processing unit 120 may re-execute the ink amount detection process shown in FIG. 18 using the abnormality flag as a trigger. Alternatively, the processing unit 120 may perform a notification process that prompts the user to confirm the ink tank 310 based on the abnormality flag.

In addition, the amount of ink increases as the user replenishes the ink IK. However, the amount of ink increases even when the ink IK is not replenished, such as a temporary change in the liquid level due to the shaking of the electronic device 10, backflow of the ink IK from the tube 105, and a detection error of the photoelectric conversion device 322. Can be considered. Therefore, when the ink increase amount is equal to or less than a given threshold value, the processing unit 120 determines that the ink IK is not replenished and the increase width is within an acceptable error range. In this case, since it is determined that the change in the ink amount is in a normal state, no additional processing is particularly performed.

On the other hand, when the ink increase amount is larger than a given threshold value, the processing unit 120 determines that the ink has been replenished and sets the ink replenishment flag to ON. The ink replenishment flag is used, for example, as an execution trigger of the ink type determination process described later. Further, the ink replenishment flag may be used as a trigger of the process of resetting the initial value in the consumption amount calculation process.

However, when the amount of ink increase is larger than a given threshold value, it cannot be denied that some abnormality may cause an unacceptably large error. Therefore, the processing unit 120 performs a notification process for requesting the user to input whether or not the ink IK has been replenished, and determines whether to set the abnormality flag or the ink replenishment flag based on the input result of the user. You may.

3.2 Ink amount detection processing that can reduce the amount of data As described above with reference to FIGS. 13 and 14, the output signal OS of the photoelectric conversion device 322 is transmitted to the AFE circuit 130, and the AFE circuit 130 is digital data. The pixel data is transmitted to the processing unit 120. The AFE circuit 130 includes a memory (not shown), and it is necessary to temporarily store pixel data after A / D conversion in the memory. Hereinafter, an example in which the memory is SRAM will be described.

FIG. 19 is a diagram illustrating an arrangement of the ink tank 310 and the photoelectric conversion device 322. As described above with reference to FIG. 9, the photoelectric conversion device 322 is a linear image sensor, and is arranged so that the longitudinal direction is the vertical direction. That is, the plurality of photoelectric conversion elements included in the photoelectric conversion device 322 are arranged side by side in the vertical direction. The number of photoelectric conversion devices 322 included in one sensor 190 can be variously modified, and the number of photoelectric conversion elements included in one photoelectric conversion device 322 can also be variously modified. That is, the number of photoelectric conversion elements included in the sensor 190 can be modified in various ways. Hereinafter, the number of photoelectric conversion elements included in the sensor 190 is defined as q. q is an integer greater than or equal to 2.

For example, the AFE circuit 130 receives an output signal OS including q signals based on q photoelectric conversion elements, A / D converts the output signal OS, and q pixel data which is an A / D conversion result. To the SRAM. As described above with reference to FIGS. 15 and 16, it is conceivable that the output signal OS of the photoelectric conversion device 322 includes q / k signals in which continuous k pixels are totaled. Will be described later, and here, an example in which the photoelectric conversion device 322 outputs in units of one pixel will be described.

When one pixel data is represented by 8 bits, the SRAM included in the AFE circuit 130 needs to be able to store q × 8 bit data, which increases the size of the SRAM. The interface between the AFE circuit 130 and the processing unit 120 is, for example, a serial interface such as an SPI (Serial Peripheral Interface). Therefore, when the amount of transferred data is large, the time required for communication becomes long. Therefore, the sensor 190 of the present embodiment may reduce the amount of data. Hereinafter, a specific method will be described.

3.2.1 Designation of reading area and two-step reading For example, the processing unit 120 designates a reading area for the sensor 190 and determines the amount of ink based on the pixel data of the reading area output from the sensor 190. .. The reading area here represents a part of the area where the sensor 190 can detect light. The region where the sensor 190 can detect light is the region where the photoelectric conversion element is arranged.

In this embodiment, the photoelectric conversion element may be arranged in a wider range than the region corresponding to the ink low to the ink full. Ink claw corresponds to the minimum amount of ink IK to be detected, and ink full corresponds to the maximum amount of ink IK to be detected. Hereinafter, the area corresponding to the ink low to the ink full is referred to as a detection area.

For example, when the detection region is in the range corresponding to 180 photoelectric conversion elements, the sensor 190 having 200 photoelectric conversion elements is used. In this way, even if the relative position of the sensor unit 320 with respect to the ink tank 310 deviates in the ± Z direction due to the mounting error, it is possible to perform the ink amount detection process for the detection area. Is. However, in this case, the photoelectric conversion element is arranged at a position that is not the target of ink amount detection, and it is less necessary to use the output of the photoelectric conversion element for processing.

The designation of the reading region in the present embodiment may specify the detection region in the region where the photoelectric conversion element is provided. For example, the ink tank 310 may have a mark at a predetermined position on the wall surface on the sensor unit 320 side. The processing unit 120 detects the mark position based on the output of the sensor 190. Since the relationship between the mark position and the detection area is known, the processing unit 120 designates the target range of the ink amount detection process as the reading area based on the mark detection result.

The photoelectric conversion device 322 outputs in units of one pixel as described above, and the AFE circuit 130 receives an output signal OS including 200 signals based on 200 photoelectric conversion elements. The AFE circuit 130 stores in SRAM the pixel data obtained by A / D converting the signals corresponding to the 180 designated photoelectric conversion elements out of the 200 types of signals. On the other hand, the AFE circuit 130 discards the signals corresponding to the 20 undesignated photoelectric conversion elements out of the 200 types of signals without storing them in the SRAM. By doing so, it is possible to reduce the amount of data stored in the SRAM and the amount of data transmitted to the processing unit 120.

The designated read area may be a part of the detection area in consideration of further reducing the amount of data. For example, by setting the read area as the lower half area of the detection area, it is possible to reduce the number of pixel data stored in the SRAM to 90. Here, the bottom represents the -Z direction. However, if the liquid level of the ink IK is present in the upper half of the detection area, the amount of ink cannot be detected appropriately. Specifically, the values of all the pixel data become small, and the liquid level position cannot be determined.

Therefore, the processing unit 120 may estimate the position of the liquid level of the ink IK based on the low-resolution pixel data output by the sensor 190, and designate a region including the estimated liquid level position as the reading area. Then, the processing unit 120 determines the amount of ink based on the high-resolution pixel data in the reading region output from the sensor 190. In other words, the processing unit 120 instructs the sensor 190 to read in two steps.

By first estimating the approximate position of the liquid level and specifying the reading area based on the estimated position, it is possible to increase the probability that the liquid level exists in the reading area. Therefore, even when a part of the detection area is excluded from the reading area, the ink amount can be appropriately determined. The read area in this case preferably does not include an area outside the detection area. As described above, the photoelectric conversion element outside the detection region is provided in consideration of mounting error and the like, and it is not necessary to detect the liquid level outside the detection region. Hereinafter, an example will be described in which the detection region is a region corresponding to 180 photoelectric conversion elements and a part of the region is designated as a reading region. However, in consideration of reducing the amount of data, the reading region may be limited to a part of the region where the photoelectric conversion element is provided, and it is not prevented that the reading region includes a region outside the detection region.

Various methods can be considered for acquiring low-resolution pixel data and setting the reading area. For example, the sensor 190 includes a plurality of photoelectric conversion elements, and the processing unit 120 may acquire pixel data obtained by thinning out the output from some of the photoelectric conversion elements as low-resolution pixel data. Good.

FIG. 20 is an explanatory diagram of a method for acquiring low-resolution pixel data. For example, the processing unit 120 acquires low-resolution pixel data by dividing the detection area into sections for every 18 pixels, leaving one pixel for each section, and instructing the sensor 190 to thin out 17 pixels. For example, when the lowest pixel of each section is left, the processing unit 120 does not thin out the first pixel, the 19th pixel, the 37th pixel, ..., The 163rd pixel from the bottom of the detection area, and sets the other pixels. The thinning instruction is transmitted to the sensor 190. The AFE circuit 130 saves the pixel data of the pixel instructed not to thin out in the SRAM, and discards the other pixel data without saving. In this case, the SRAM may store pixel data for 10 pixels, and the amount of data can be reduced. Hereinafter, the 10 pixel data will be referred to as 1st pixel data to 10th pixel data.

When the liquid level exists at the position shown in FIG. 20, the values of the 1st pixel data to the 3rd pixel data are determined to be the ink detection area because the values are equal to or less than the threshold value, and the values of the 4th pixel data to the 10th pixel data are high. Since it is larger than the threshold value, it is determined to be an ink non-detection area. That is, it is estimated that the liquid level of the ink IK is between the position of the photoelectric conversion element corresponding to the third pixel data and the position of the photoelectric conversion element corresponding to the fourth pixel data. Hereinafter, the position of the photoelectric conversion element corresponding to the given pixel data is simply referred to as the position of the pixel data. In the above example, the liquid level position is estimated to be in the section between the 37th pixel and the 55th pixel among the 180 pixels corresponding to the detection region. As described above, by using the low-resolution pixel data, it is possible to reduce the amount of data while estimating the liquid level covering a wide range of the detection area, in a narrow sense, the entire detection area.

The processing unit 120 sets the reading area so as to include a corresponding area between the third pixel data and the fourth pixel data. However, when the liquid level position is located near the photoelectric conversion element of the 37th pixel, the value of the third pixel data may change significantly depending on the fluctuation of the liquid level or the like. In other words, it is erroneously determined that the liquid level position is located between the 37th pixel to the 55th pixel due to noise, and it is possible that the actual liquid level position exists below the 37th pixel. .. Similarly, it is conceivable that the actual liquid level position exists above the 55th pixel.

Therefore, the processing unit 120 is the t (t is an integer satisfying 2 ≦ t ≦ s-2) pixel of the first pixel data to the s (s is an integer of 4 or more) pixel data which is the pixel data after thinning. When it is estimated that there is a liquid level position between the data and the t + 1 pixel data, the area obtained by expanding the area is designated as the reading area. Specifying this expanded area means, for example, in this case, designating an area including a section between the t-1 pixel data and the t + 2 pixel data as a read area. In the above example, s = 10 and t = 3.

FIG. 21 is a diagram showing a specific example of the designated read area. In FIG. 21, for convenience of drawing, the number of photoelectric conversion elements included in one section is four, but in the above example, the number of photoelectric conversion elements included in one section is 18. The processing unit 120 includes not only the section corresponding between the third pixel data and the fourth pixel data, but also the section corresponding between the second pixel data and the third pixel data, and the fourth pixel data and the fifth pixel data. Also specify the corresponding interval between and in the read area. For example, a section corresponding to the 19th pixel corresponding to the second pixel data to the 73rd pixel corresponding to the fifth pixel data is designated as the read area.

When the liquid level is determined to be between the first pixel data and the second pixel data, there is no region below that, so the processing unit 120 is between the first pixel data and the third pixel data. Specify two sections as the read area. Similarly, when it is determined that the liquid level is above the 10th pixel data, the processing unit 120 sets two sections between the 9th pixel data and the 10th pixel data and above the 10th pixel data as a reading area. specify. Further, the first pixel data existing at the end point of the detection region can be omitted. Even when the first pixel data is omitted, it is possible to determine whether or not the liquid level is lower than the second pixel data based on the value of the second pixel data.

The processing unit 120 acquires pixel data that is not thinned out in the reading area as high-resolution pixel data. In the above example, the AFE circuit 130 discards the information of the 1st to 18th pixels based on the designation of the reading area from the processing unit 120, and the AFE circuit 130 discards the information of the 55 pixels corresponding to the 19th to 73rd pixels. The pixel data is saved in the SRAM, and the information of the 74th pixel to the 180th pixel is discarded. The processing unit 120 acquires 55 pixel data from the AFE circuit 130 as high-resolution pixel data, and determines the liquid level position by performing processing such as threshold value determination as described above using FIG.

FIG. 22 is a flowchart illustrating an ink amount detection process using the methods shown in FIGS. 20 and 21. When this process is started, the process unit 120 first instructs the sensor 190 to output low-resolution pixel data (S201). Information for identifying the pixels to be thinned out and the pixels to be thinned out is stored in, for example, the storage unit 140, and the processing unit 120 gives an instruction in S201 by reading the information. The sensor 190 outputs low-resolution pixel data based on an instruction from the processing unit 120. The processing unit 120 acquires low-resolution pixel data from the sensor 190 (S202).

Next, the processing unit 120 estimates the approximate position of the liquid level based on the low-resolution pixel data (S203). The process of S203 is, for example, as described above, a process of comparing the pixel data after thinning out with the threshold value. The processing unit 120 sets a reading area used for acquiring high-resolution pixel data based on the estimated liquid level position (S204).

The processing unit 120 indicates the reading area to the sensor 190 (S205). Specifically, in the reading area, the sensor 190 is instructed to output high-resolution pixel data without thinning out the pixels. The sensor 190 outputs high-resolution pixel data based on an instruction from the processing unit 120. The processing unit 120 acquires high-resolution pixel data from the sensor 190 (S206).

The processing unit 120 determines the liquid level position with high accuracy based on the acquired high-resolution pixel data (S207). The process of S207 is the same as that of S103 of FIG. 18, and is a process of comparing the value of the pixel data and the threshold value, or comparing the slope of the pixel data and the threshold value.

Further, the low-resolution pixel data for estimating the approximate position of the liquid surface is not limited to the pixel data acquired by thinning out some pixels. For example, pixel data including information corresponding to the total or average of the outputs of a plurality of pixels may be used as low-resolution pixel data.

FIG. 23 is a diagram illustrating another method of performing two-step reading. As shown in FIG. 23, a first region, a second region, and a third region that overlaps a part of the first region and a part of the second region are set in the region that can be read by the sensor 190. The area that can be read by the sensor 190 may be the entire area where the photoelectric conversion element is provided, or may be a detection area. In the example of FIG. 23, the first region shown in B1 is the lower half region of the detection region, and the second region shown in B2 is the upper half region of the detection region R2. The lower half of the third region shown in B3 overlaps with the first region, and the upper half overlaps with the second region. More specifically, the first region is the first pixel to the 90th pixel, the second region is the 91st pixel to the 180th pixel, and the third region is the 46th pixel to the 135th pixel. However, various modifications can be made for the specific range of each region.

The low-resolution pixel data in the example of FIG. 23 includes the first data based on the total output of the photoelectric conversion elements included in the first region, the second data based on the total output of the photoelectric conversion elements included in the second region, and the second data. Includes third data based on the sum of the outputs of the photoelectric conversion elements included in the third region.

For example, the first data is the total or average of 90 pixel data from the first pixel to the 90th pixel. As described above, the photoelectric conversion device 322 outputs an output signal OS including signals corresponding to 180 photoelectric conversion elements to the AFE circuit 130. The AFE circuit 130 sequentially A / D-converts 180 analog signals included in the output signal OS.

The AFE circuit 130 includes, for example, a digital adder, sequentially adds pixel data of the first pixel to the 90th pixel, and stores only the addition result in the SRAM. Since the total of 90 pixel data is a value in the range of 0 to 255 × 90, it can be expressed by 15 bits. By adding up to the pixel data of the 90th pixel, the total output of the first region is calculated. The AFE circuit 130 may output the total as the first data to the processing unit 120, or may perform an operation for obtaining the average and output the obtained average as the first data to the processing unit 120. Similarly, the AFE circuit 130 sequentially adds the pixel data of the 91st pixel to the 180th pixel, and obtains the second data by storing only the addition result in the SRAM. The AFE circuit 130 sequentially adds the pixel data of the 46th pixel to the 135th pixel, and obtains the third data by storing only the addition result in the SRAM.

For example, the AFE circuit 130 performs an addition process for obtaining the first data for the first pixel to the 45th pixel. For the 46th to 90th pixels, two digital adders are used to perform an addition process for obtaining the first data and an addition process for obtaining the third data in parallel. By using two digital adders for the 91st pixel to the 135th pixel, the addition process for obtaining the third data and the addition process for obtaining the second data are performed in parallel. Since the addition process of the first data is completed in this range, the adder for the first data can be diverted to the addition process for obtaining the second data. For the 136th to 180th pixels, an addition process for obtaining the second data is performed. In this case, the SRAM may hold three addition results, for example, it suffices to have an area of 3 × 15 bits. That is, the amount of data can be reduced as compared with the case where 180 8-bit pixel data are held. Although the example of digitally performing the addition processing has been shown above, it is not prevented that the AFE circuit 130 performs the addition processing in an analog manner.

The processing unit 120 designates a read area based on the first data, the second data, and the third data. Hereinafter, an example in which the first to third data are averages will be described.

When the first region is entirely included in the ink detection region, the value of all pixel data corresponding to the first region is sufficiently small, so that the first data is also a small value. On the other hand, when all the first regions are included in the ink non-detection region, the values of all pixel data corresponding to the first region are sufficiently large, so that the first data is also large. In order to simplify the explanation, it is assumed that the pixel data value in the ink detection region is normalized to 0 and the pixel data value in the ink non-detection region is normalized to 255. In this case, if the first region is all the ink detection region, the first data is 0, and if the first region is all the ink non-detection region, the first data is 255.

When the liquid level is at any position in the first region, the pixel data from the first pixel to the predetermined pixel in the first region becomes 0, and the pixel data above it becomes 255. The first data, which is the average, is a value between 0 and 255, and the value changes according to the height of the liquid level. For example, when the liquid level is in the center of the first region, the number of pixel data to be 0 and the number of pixel data to be 255 are equal, so that the value of the first data is about 128. The same applies to the second region and the third region, and the position of the liquid level in each region can be estimated according to the values of the second data and the third data.

The processing unit 120 determines the read area based on the relationship between the first to third data. For example, the processing unit 120 determines whether the estimated position of the liquid level is below B4, between B4 and B5, or above B5. B4 is a position near the center of the overlapping portion of the first region and the third region. In this case, the first data has a value of about 50, the second data has a value of about 255, and the third data has a value of about 200. Further, B5 is a position near the center of the overlapping portion of the second region and the third region. In this case, the value of the first data is about 0, the value of the second data is about 200, and the value of the third data is about 50. By comparing these values with the actual first to third data, it is possible to determine whether the estimated position of the liquid level is below B4, between B4 and B5, or above B5. ..

As described above with reference to FIG. 17, the pixel data output by the sensor 190 does not suddenly change from 0 to 255 at the liquid level of the ink IK, and there is a region that takes an intermediate value. Further, as will be described later with reference to FIGS. 28 to 33 and the like, the specific waveform differs depending on the type of ink IK and the wavelength band of light. Since the first data is the total or average in the first region, detailed information in the ± Z direction is lost, and it is difficult to estimate the liquid level position with high accuracy only from the first data. Similarly, it is not easy to estimate the liquid level with high accuracy using the second data alone or the third data alone. In that respect, since it is possible to improve the estimation accuracy of the liquid level position by obtaining the first to third data respectively and comparing the relationships as described above, an appropriate reading area can be set. For example, the processing unit 120 is based on the magnitude relationship between the first data to the third data, the ratio between the first data and the second data, the ratio between the first data and the third data, the ratio between the second data and the third data, and the like. To estimate the liquid level position.

As shown in FIG. 23, the first region is a region including the position of the liquid surface corresponding to the ink low, and the second region is a region including the position of the liquid surface corresponding to the ink full. The processing unit 120 may designate an area corresponding to any one of the first area, the second area, and the third area as the reading area based on the first data, the second data, and the third data.

In the example shown in FIG. 23, the detection region is covered by the first to third regions. Therefore, regardless of the position of the liquid level in the detection region, the liquid level position can be accurately determined by setting any of the first to third regions as the reading region. When only the first region and the second region are set, if the liquid level is near the boundary between the first region and the second region, the actual liquid level may deviate from the reading region. However, by providing the third area, an appropriate read area can be set even in such a case. Specifically, when the estimated position of the liquid level is lower than B4, the first region is set as the reading region. When the estimated position is between B4 and B5, the third area is set as the reading area. When the estimated position is above B5, the second area is set as the reading area. The actual read area does not have to match any one of the first to third areas, and an area substantially equal to any one of the areas may be set as the read area.

The processing flow in FIG. 23 is the same as in FIG. 22. However, the first to third data are used as the low resolution pixel data (S201, S202). Further, the estimation of the liquid level position is determined based on the set of the first to third data as described above (S203). The read area is an area corresponding to any of the first to third areas (S204). The process after determining the reading area is the same, and the processing unit 120 executes a process of determining the liquid level using the data in which the pixels are not thinned out in the reading area as high-resolution pixel data.

Even when the method shown in FIG. 23 is used, it is possible to estimate the approximate liquid level position over the entire detection area and determine the liquid level position with high accuracy by setting an appropriate reading area. It will be possible. At that time, since the low-resolution pixel data is used in the first reading and the reading area is limited in the second reading using the high-resolution pixel data, the amount of data can be reduced.

In addition, in FIG. 23, an example in which three regions of the first to third regions are set as the detection region has been described. However, the processing of this embodiment is not limited to this. For example, five regions, a first region to a fifth region, may be set as the detection region. The first to third regions divide the detection region into three. For example, the first region is the first pixel to the 60th pixel, the second region is the 61st pixel to the 120th pixel, and the third region is the 121st pixel to the 180th pixel. The fourth region overlaps a part of the first region and a part of the second region, and the fifth region overlaps a part of the second region and a part of the third region. The fourth region is the 31st to 90th pixels, and the fifth region is the 91st to 150th pixels. The processing unit 120 sets the area corresponding to any of the first area to the fifth area as the reading area based on the first to fifth data corresponding to the total of each area. Even in this way, it is possible to execute an appropriate ink amount detection process while reducing the amount of data. Further, the set area can be expanded to 2 × j + 1 (j is an integer of 1 or more).

3.2.2 Reading once The data amount reduction in the ink amount detection process is not limited to the above method. For example, the processing unit 120 determines the amount of ink based on the low-resolution pixel data output by the sensor 190 in the first reading area and the high-resolution pixel data output by the sensor 190 in the second reading area other than the first reading area. To do. In this way, by setting the area for outputting the low-resolution pixel data and the area for outputting the high-resolution pixel data, the amount of data can be reduced as compared with the case where the high-resolution pixel data is used for the entire area. The first read area and the second read area are each a part of the area that can be read by the sensor 190, and in a narrow sense, a part of the detection area. The second read area is an area different from the first read area, and specifically, is an area that does not overlap with the first read area. More specifically, the second read area is an area other than the first read area in the area that can be read by the sensor 190 or the detection area.

Specifically, the sensor 190 outputs low-resolution pixel data and high-resolution pixel data by one reading. By doing so, it is possible to shorten the time required for the ink amount detection process as compared with the two-step reading described above using FIGS. 20 to 23.

FIG. 24 is a setting example of the first read area and the second read area. C1 in FIG. 24 corresponds to the first read area, and C2 corresponds to the second read area. As shown in FIG. 24, the second reading region is a region including the position of the liquid level corresponding to the inclaw. Here, the ink low represents a state in which the amount of ink IK in the ink tank 310 is less than a given amount, and in a narrow sense, corresponds to the minimum amount of ink IK to be detected. The ink claw is, for example, the ink end described above in FIG. When the ink IK in the ink tank 310 runs out, the ink IK is not ejected to the print medium P, so that there is a possibility that waste paper may occur. In addition, since blank printing occurs in the print head 107, it causes head failure such as ejection failure. By setting the second reading area as shown in FIG. 24, it is possible to accurately detect the ink row using high-resolution pixel data, and it is possible to suppress paper loss and head failure. As shown in FIG. 24, the high resolution pixel data is pixel data in which pixels are not thinned out.

Further, the processing unit 120 may acquire pixel data obtained by thinning out the outputs from some of the photoelectric conversion elements among the plurality of photoelectric conversion elements as low-resolution pixel data. For example, in the same manner as in the above-described example using FIG. 21, the sensor 190 divides the pixels included in the first reading area into sections of predetermined pixels, leaves one pixel from each section, and thins out the other pixels. Outputs low resolution pixel data.

The processing unit 120 performs a process of designating the first reading area and the second reading area for the sensor 190. In the example of FIG. 24, the processing unit 120 specifies a boundary pixel that is a boundary between the first reading area and the second reading area. The boundary in FIG. 24 corresponds to C3. For example, when the sensor 190 sequentially acquires pixel data from the lower pixel to the upper pixel, the processing unit 120 outputs the pixel data from the first pixel to the boundary without thinning out, and is above the boundary. As for the pixels, the sensor 190 is instructed to output low-resolution pixel data obtained by thinning out some pixels.

In this way, the sensor 190 can output appropriate low-resolution pixel data and high-resolution pixel data based on the instruction from the processing unit 120. A fixed value may be used for the position of the boundary pixel, the ratio of the pixels thinned out in the first reading region, and the like, or the processing unit 120 may dynamically change the position.

The settings of the first read area and the second read area are not limited to FIG. 24. In the example of FIG. 25, E1 corresponds to the first read area, and E2 and E3 correspond to the second read area. The boundaries between the first read area and the second read area are E4 and E5. As shown in FIG. 25, the second reading region is a region including the position of the liquid level corresponding to the ink full. Note that FIG. 25 shows an example in which two regions are set as the second reading region, a region including the position of the liquid level corresponding to the ink low and a region including the position of the liquid level corresponding to the ink full.

Ink full represents a state in which the amount of ink is sufficiently large, and in a narrow sense, represents the maximum amount of ink IK to be detected. More specifically, ink full is a state in which the amount of ink is close to the maximum value of the capacity of the ink tank 310. When the user further replenishes the ink IK from the ink-full state, the ink overflows from the ink tank 310, which causes stains or malfunctions inside the printing apparatus. Therefore, when ink full is detected, the processing unit 120 may perform a notification process for suppressing further ink replenishment. By setting the region including the position of the liquid level corresponding to the ink full as the second reading region, the detection accuracy of the ink full can be improved, so that the overflow of the ink can be appropriately suppressed.

As shown in FIGS. 24 and 25, the amount of data can be reduced by setting the relatively important area as the second read area and the less important area as the first read area. become. In addition, important states in the control of the printing apparatus such as ink low and ink full can maintain the same detection accuracy as when the amount of data is not reduced.

3.2.3 Processing using the results of past ink amount detection processing In the above, various methods that can reduce the amount of data in one ink amount detection processing have been described. In the present embodiment, it is assumed that the ink amount detection process is repeatedly executed. This is because the amount of ink fluctuates with the passage of time, and the fluctuation is appropriately detected. Fluctuations in the amount of ink may be a decrease due to the execution of printing or maintenance, or an increase due to the user replenishing ink IK.

However, fluctuations in the amount of ink can be predicted to some extent. For example, the amount of ink IK consumed by printing can be estimated by the product of the number of times ink IK is ejected from the nozzle and the amount of ink ejected at one time. In addition, the amount of ink IK consumed by one flushing or cleaning can be estimated in advance based on the design. Therefore, the processing unit 120 can estimate the current ink amount based on the ink amount determined by the previous ink amount detection process and the execution status of printing and maintenance from the previous ink amount detection process to the present. .. Alternatively, in order to reduce the processing load, a simple ink amount estimation may be performed based on the result of the previous ink amount detection process and the elapsed time. When further simplifying the process, it is not hindered that the result of the previous ink amount detection process is used as it is as the estimated amount of the current ink amount.

In this case, the amount of ink can be appropriately determined by intensively searching the region including the liquid level position corresponding to the estimated amount of ink IK. For example, the processing unit 120 designates a first reading area and a second reading area for the sensor 190 based on the predicted amount of ink amount.

Specifically, the processing unit 120 sets a region including the liquid level position corresponding to the estimated ink amount as the second reading region. For example, the estimated liquid level position is centered, and the region of a given pixel range is defined as the second reading region. The processing unit 120 uses an area other than the second read area as the first read area in the detection area.

FIG. 26 is an example of region designation based on the predicted amount of ink. F1 in FIG. 26 is the liquid level position corresponding to the predicted amount. In this case, the processing unit 120 specifies to the sensor 190 that F2, which is an area including F1, is set as the second reading area, and the other areas F3 and F4 are set as the first reading area. In this way, it is possible to read the region where the liquid level is likely to exist with high accuracy. Further, since the determination is performed using the low-resolution pixel data also in the region other than the second reading region, it is possible to follow the fluctuation even if the ink amount fluctuation exceeds the expectation. For example, when the user replenishes the ink IK, the amount of ink increases sharply, but even in that case, the ink liquid level can be estimated.

Alternatively, the first reading area may not be used in consideration of reducing the load of the ink amount detection process and increasing the speed. Specifically, when the predicted amount of ink can be acquired, the processing unit 120 acquires high-resolution pixel data for only a part of the detection area, as in the second-stage reading shown in FIG. To do. Not only is the high-resolution pixel data not acquired for the other areas of the detection region, but the acquisition of low-resolution pixel data is also omitted. However, in this case, if the actual liquid level exists outside the reading area, the amount of ink cannot be detected appropriately. Therefore, when the processing unit 120 determines that the liquid level exists outside the reading region, the processing unit 120 performs the ink amount detection process again using any of the methods shown in FIGS. 20, 21, 23 to 25. That is, the processing unit 120 performs ink amount detection processing for the entire detection area when the ink amount is not detected or when the ink amount cannot be tracked appropriately, and in other situations, a part of the detection area is used. The target ink amount detection process may be performed.

3.2.4 Additive reading It is also possible to combine the above-mentioned method for reducing the amount of data and the above-mentioned method for reducing the amount of light unevenness using FIGS. 15 and 16.

The process of obtaining the total output of continuous k pixels may be performed by the processing unit 120. In this case, the processing unit 120 performs a process of obtaining the total of k pixel data corresponding to continuous k pixels among the pixel data acquired from the sensor 190. When the low-resolution pixel data is data obtained by thinning out some pixels, the low-resolution pixel data may not have pixel data corresponding to continuous k pixels. Therefore, in this case, the processing unit 120 performs a process of obtaining the total of k pixel data corresponding to continuous k pixels for the high resolution pixel data. Alternatively, low-resolution pixel data such that continuous k pixels remain even after thinning may be used. For example, in FIG. 20, instead of leaving only the 1st pixel, 19th pixel, 37th pixel, ..., 163rd pixel, 1st to 3rd pixels, 19th to 21st pixels, 37th to 39th pixels, ... -The thinning is performed so as to leave the 163rd to 165th pixels. The processing unit 120 transmits an instruction to output the pixel data of the pixel to the sensor 190.

Alternatively, the process of obtaining the total output of continuous k pixels may be performed in the sensor 190, or in a narrow sense, in the photoelectric conversion device 322 as shown in FIG. In this case, the AFE circuit 130 receives an output signal OS including q / k signals. For example, as described above, q = 180 and k = 3, and the AFE circuit 130 can acquire 60 pixel data.

In this case, it is possible to perform the same processing as in the above example by considering that the pixel corresponding to the detection area is changed to 60 pixels instead of 180 pixels. For example, in the first-stage reading shown in FIG. 20, some of the 60 pixels are thinned out. For example, the AFE circuit 130 outputs low-resolution pixel data by thinning out 5 pixels, leaving 1 pixel for every 6 pixels. In the second-stage reading shown in FIG. 21, high-resolution pixel data is output by using the pixels in the reading area without thinning out. For example, in the example of FIG. 21 in which the light amount unevenness is not considered, in addition to the four pixels of the t-1 pixel, the t pixel, the t + 1 pixel, and the t + 2 pixel, 17 × 3 = 51 pixels in between, a total of 55 pixels The data was acquired as high resolution pixel data. In this modification, in addition to the four pixels of the t-1 pixel, the t pixel, the t + 1 pixel, and the t + 2 pixel, 5 × 3 = 15 pixels in between may be set as the reading area, and the high resolution pixel data may be obtained. It becomes the pixel data for the 19 pixels. The same applies to FIGS. 24 to 26. In the first reading area, low-resolution pixel data is output by thinning out 5 pixels per 6 pixels, and in the second reading area, the pixels in the area are not thinned out. As a result, high-resolution pixel data is output. The method shown in FIG. 23 is the same as the above example except that the first to third regions are regions for 30 pixels each.

That is, even when suppressing the unevenness of the amount of light, the processing unit 120 estimates the position of the liquid surface of the ink IK based on the low-resolution pixel data output by the sensor 190, as in the examples of FIGS. 20 to 23. Specify the area containing the estimated liquid level position as the reading area. Then, the processing unit 120 determines the amount of ink based on the high-resolution pixel data in the reading region output from the sensor 190. Alternatively, as in the examples of FIGS. 24 to 26, the processing unit 120 has the low resolution pixel data output by the sensor 190 in the first reading area and the height output by the sensor 190 in the second reading area other than the first reading area. The amount of ink is determined based on the resolution pixel data.

When acquiring low-resolution pixel data, the processing unit 120 may control the sensor 190 to output pixel data corresponding to the total output of continuous k pixels. Specifically, the low-resolution pixel data here is pixel data obtained by thinning out the outputs from some of the photoelectric conversion elements among the plurality of photoelectric conversion elements. That is, the low-resolution pixel data is pixel data acquired by thinning out some pixels.

When pixel thinning is performed, the information of the thinned pixels is lost. When the outputs of continuous k pixels are not summed, for example, 17 out of 18 pixels are thinned out as described above. Since the ratio of the remaining pixels is small, when the pixel data of the remaining pixels contains noise, the influence of the noise on the ink amount detection process becomes large. On the other hand, when the total of continuous k pixels is obtained in the sensor 190, the pixel data output from the sensor 190 includes information for k pixels. For example, in the same example as in FIG. 20, when 10 pixel data is output as low resolution pixel data, the first pixel data corresponds to the total of the first pixel to the third pixel. Therefore, even if the pixel data of the first pixel contains noise, the influence of the noise can be suppressed by using the pixel data of the second pixel and the third pixel. That is, by performing the process for suppressing the light amount unevenness, it is possible to suppress the influence of noise different from the light amount unevenness. It can be said that the process of suppressing the unevenness of the amount of light is particularly effective when acquiring low-resolution pixel data in which the weight per pixel becomes large.

4. Ink Type Determination In the present embodiment, the processing unit 120 may determine the ink type of the ink IK in the ink tank 310 based on the output of the sensor 190.

4.1 Outline of Ink Type Determining As described above with reference to FIGS. 2 and 3, the electronic device 10 may include a plurality of ink tanks 310 each filled with different types of ink IK. In this case, the user may mistakenly fill another ink tank 310 such as the ink tank 310b with the ink IKa to be filled in the ink tank 310a. Further, even if the electronic device 10 is a monochrome printing device having one ink tank 310, if the user also uses printing devices of different models, the ink IK used for other printing devices can be erroneously filled. There is sex. Furthermore, even if the user uses only one monochrome printing device, many different inks are distributed in the market depending on the model, so the user mistakenly purchases ink for a different model. The possibility of filling cannot be denied.

For example, when the ink tank 310 to be filled with yellow ink is filled with magenta ink, the color tone of the print result greatly deviates from the desired color tone. That is, in order to perform proper printing, it is necessary to properly detect ink color errors. Therefore, the processing unit 120 determines the ink color as the ink type.

FIG. 27 is a diagram for explaining the spectral emission characteristics of the light applied to the ink IK and the spectral reflection characteristics of the ink IK. The horizontal axis of FIG. 27 represents the wavelength, and the vertical axis represents the spectroscopic emission characteristic or the spectral reflection characteristic.

In the present embodiment, the ink IK is irradiated with R light corresponding to red, G light corresponding to green, and B light corresponding to blue. For example, the wavelength band of B light is about 430 to 500 nm, the wavelength band of G light is about 500 to 600 nm, and the wavelength band of R light is about 600 to 650 nm. However, various modifications can be made for the wavelength band, peak wavelength, full width at half maximum, etc. of each light.

Further, as shown in FIG. 27, the spectral reflection characteristics differ depending on the color of the ink IK. For example, black ink has low reflectance in a wide wavelength band corresponding to RGB. Yellow ink has a low reflectance in the wavelength band of B light, and has a very high reflectance in the wavelength band of G light and R light. Magenta ink has low reflectance in the wavelength band of B light and G light, and high reflectance in the wavelength band of R light. Cyan ink has a slightly high reflectance in the wavelength band of B light, and has a low reflectance in the wavelength band of G light and R light.

When the input of the photoelectric conversion element is D, the spectral emission characteristic of the irradiation light is S (λ), and the spectral reflection characteristic of the ink IK is R (λ), D is represented by, for example, the following equation (1). .. Since D is the result of receiving light from the region where the ink IK exists, the pixel data in the ink detection region has a value that correlates with the spectral sensitivity characteristics of D and the photoelectric conversion element. As described above, since the spectral reflection characteristic R (λ) in the RGB wavelength band differs depending on the ink color, the characteristics of the pixel data in the ink detection region differ depending on the ink color.

28 to 33 are waveforms representing pixel data for each ink color of the pigment ink. Similar to the example shown in FIG. 17, the horizontal axis of each figure represents the position of the photoelectric conversion device 322 in the longitudinal direction, and the vertical axis represents the value of the pixel data corresponding to the photoelectric conversion element provided at the position. The vertical line in each figure represents the position of the liquid level of the ink IK at the time of pixel data measurement. For example, in the case of the black ink shown in FIG. 28, the liquid level exists at a position around 7.3.

FIG. 28 represents the pixel data of black ink. As shown in FIG. 28, the pixel data of the black ink is 0 or a small value sufficiently close to 0 in the ink detection region below the liquid surface regardless of whether RGB light is received. .. Further, in the ink non-detection region, the pixel data has a large value of about 200. Since the value of the pixel data in the ink non-detection region is not significantly affected by the type of ink IK, the description of the ink non-detection region will be omitted from FIG. 29 onward.

FIG. 29 shows pixel data of cyan ink. As shown in FIG. 29, the pixel data for the R light and G light of the cyan ink is 0 or a small value sufficiently close to 0 in the ink detection region. On the other hand, the pixel data for the B light has a value of about 100 in the ink detection region. That is, the pixel data of the ink detection region for B light is small enough to be distinguished from the ink non-detection region, but is sufficiently large compared to 0.

FIG. 30 represents the pixel data of magenta ink. As shown in FIG. 30, the pixel data for the R light of the magenta ink is about 170 to 200 in the ink detection region. The pixel data for G light is a small value sufficiently close to 0 in the ink detection region. The pixel data for the B light has a value of about 50 or less in the ink detection region.

FIG. 31 shows pixel data of yellow ink. As shown in FIG. 31, the pixel data for the R light of the yellow ink has a value close to 255 in the ink detection region. The pixel data for G light has a value of around 150 in the ink detection region. The pixel data for the B light is a small value sufficiently close to 0 in the ink detection region.

Further, in the present embodiment, the white ink and the clear ink may be the targets of the ink color determination. White ink is white ink, and is used as a base when printing on a transparent material, for example. The clear ink is a transparent or translucent ink that transmits light, and is used for applications such as giving gloss to the print medium P, changing the texture, and giving thickness.

FIG. 32 represents the pixel data of the white ink. The region where the white ink is present is white, which is brighter than the wall color of the ink tank 310 in the ink non-detection region. Therefore, as shown in FIG. 32, the pixel data in the ink detection region of the white ink has a larger value than the ink non-detection region when receiving any of RGB light. Specifically, the pixel data of white ink has a value close to 255 in the ink detection region.

FIG. 33 shows the pixel data of the clear ink. As shown in FIG. 33, the pixel data of the clear ink has a value of about 100 to 150 regardless of whether it receives RGB light.

As shown in FIGS. 27 to 33, the characteristics of the pixel data in the ink detection region differ depending on the ink color due to the difference in the spectral reflection characteristics. Depending on the color of the light, the characteristic difference of the pixel data may be small, such as the R light of black ink and the R light of cyan ink, but the ink color can be determined by combining light of a plurality of colors. For example, when distinguishing between black ink and cyan ink, B light may be used.

The sensor 190 of the present embodiment detects the first light of the first wavelength band color and the second light of the second wavelength band incident from the ink tank 310 side during the period when the light source 323 emits light. The processing unit 120 determines the ink IK in the ink tank 310 based on the first light amount for the first light at the position where the ink IK is present and the second light amount for the second light at the position where the ink IK is present. Judge the ink type of. The processing unit 120 acquires the first light amount and the second light amount from the sensor 190.

The first light amount and the second light amount are specifically pixel data in the ink detection region. The first light amount and the second light amount are, for example, the minimum values of pixel data in the ink detection region. However, other information such as the average value and the median value of the pixel data in the ink detection region may be used as the first light amount and the second light amount. Further, the first wavelength band and the second wavelength band need only be different to the extent that the spectral reflection characteristics of the ink IK are different, and partial overlap is not prevented.

In this way, by using light in a plurality of wavelength bands, it is possible to appropriately determine the ink type. For example, black ink has a different amount of B light when compared with cyan ink. Further, the black ink has a different amount of R light when compared with the magenta, yellow, white, and clear inks. That is, black ink and other inks can be distinguished by using two types of light, R light and B light.

The processing unit 120 of the present embodiment may determine the ink color of the pigment ink based on the first light amount and the second light amount. As shown in FIGS. 28 to 33, since the pigment ink has different spectral reflection characteristics depending on the ink color, the output of each ink color of the sensor 190 differs to the extent that the ink color can be identified. By doing so, it becomes possible to appropriately detect an incorrect insertion of the pigment ink and the like.

Hereinafter, an example in which the ink type determination is the color determination of the pigment ink will be described. However, even if the pigment inks have the same color, the characteristics of the amount of light in the ink detection region are different because the coloring materials used differ depending on the manufacturer, model number, and the like. The difference in the coloring material here may be a difference in the substance itself as a material, or a difference in the blending ratio of a plurality of materials. For example, the waveform shown in FIG. 28 is a characteristic of a given pigment black ink, and the waveform is different in pigment black inks having different coloring materials. By using the difference in waveform, it is possible to determine the difference in type within the same color ink. Further, since the coloring materials of the pigment ink and the dye ink are different, the waveforms are different even if they are the same color. That is, the ink type determination in the present embodiment is not limited to the color determination of the pigment ink, and can be extended to the determination of the ink type including the coloring material and the like.

The light source 323 of the present embodiment may irradiate the first light and the second light. For example, the light source 323 includes a plurality of light sources having different wavelength bands of the emitted light, such as the red LED 323R, the green LED 323G, and the blue LED 323B. Alternatively, the light source 323 has a color filter, and the first light and the second light may be irradiated in a time-division manner by switching the color filter. The first light quantity is the output of the sensor 190 when the light source 323 irradiates the first light, and the second light quantity is the output of the sensor when the light source 323 irradiates the second light. As described above, by using the light source 323 capable of irradiating light of different wavelength bands, the ink type can be appropriately determined.

However, the ink type determination of the present embodiment may be performed as long as the sensor 190 can receive a plurality of lights having different wavelength bands. For example, the light source 323 irradiates light having a wide wavelength band, for example, white light, and the sensor 190 receives the first light and the second light by using a color filter. In this case, the color filter includes an R filter, a G filter, and a B filter having spectral transmission characteristics equivalent to those of the spectral emission characteristics of FIG. 27. Alternatively, the sensor 190 has a photoelectric conversion device 322 that receives the first light and a photoelectric conversion device 322 that receives the second light, and uses a prism or a half mirror to transmit the first light and the second light. It may be configured to separate and incident each separated light on the corresponding photoelectric conversion device 322.

The sensor 190 may also detect light of a third color. The processing unit 120 detects the ink type based on the third light amount, the first light amount, and the second light amount for the light of the third color. By increasing the types of light used, it becomes possible to determine the ink type in more detail. For example, it is possible not only to determine whether or not the ink IK to be determined is black ink, but also to determine how many colors the ink IK is. As can be seen from the above description, the ink color determination of the present embodiment may be a determination of whether or not the ink IK to be determined is the correct color, or a determination of specifying the color of the ink IK. May be good.

Hereinafter, the first light, the second light, and the third light are R light corresponding to the red wavelength band, G light corresponding to the green wavelength band, and B light corresponding to the blue wavelength band. Will be described. The first light and the second light are any two of R light, G light, and B light, and the combination of lights when the ink type determination is performed based on the two lights is arbitrary.

The processing unit 120 is based on the amount of R light representing the amount of R light incident on the sensor 190, the amount of G light representing the amount of G light incident on the sensor, and the amount of B light representing the amount of B light incident on the sensor. , Judge the ink type. Hereinafter, an example in which each light amount is the minimum value of the pixel data will be described, but as described above, the data representing the light amount can be variously modified.

In this way, the ink type can be determined using the three colors of RGB light. As shown in FIGS. 28 to 33, the characteristics of the light amounts of the three colors differ depending on the ink color, so that an appropriate determination can be made. Further, since the combination of the three colors of RGB corresponds to white light, it is widely used when forming an image having a natural color. That is, in the ink type determination of the present embodiment, the photoelectric conversion device 322 and the light source 323 used for a scanner or the like can be diverted.

However, as can be seen from FIG. 27, the wavelength band in which the spectral reflection characteristics differ depending on the ink color is not limited to the RGB wavelength band. Therefore, the light used for determining the ink type can be extended to other light such as V light, ultraviolet light, and infrared light corresponding to purple. In addition, the number and type of light to be used can be appropriately selected depending on which ink needs to be distinguished from which ink. For example, only one type of white light may be used, or five types of light may be used by adding infrared light and orange light in addition to RGB. When a fluorescent ink is used, it can be discriminated by using the spectral fluorescence characteristic in addition to or instead of the spectral reflection characteristic of the ink. In this case, it is desirable that the sensor 190 can detect a sensor 190 having a different wavelength band of light incident on the ink tank and a wavelength band of light incident on the sensor by using a color filter.

4.2 Judgment processing for each ink color In the position where the ink IK exists, the R light amount is the threshold Th _{Bk_R} or less, the G light amount is the threshold Th _{Bk_G} or less, and the B light amount is the threshold Th _{Bk_B} or less. In some cases, it is determined that the ink IK is black ink.

As shown in FIG. 28, when black ink is targeted, all the light amounts of RGB are sufficiently small in the ink detection region. Therefore, it can be determined whether or not the ink is black ink by determining whether or not the ink is equal to or less than a given threshold value. Each threshold value here needs to be larger than the value assumed for black ink. However, in order to prevent the ink IK of other colors from being erroneously determined to be black ink, it is not desirable to make the value excessively larger than the value assumed for black ink. For example, each threshold value is set to be a value larger than the assumed value by Δ. The specific value of Δ can be variously modified, but is, for example, about 20 to 60. Further, the value of Δ may be changed in each of RGB. For example, (Th _{Bk_R} , Th _{Bk_G} , Th _{Bk_B} ) = (50, 50, 50). By performing the determination using such a threshold value, for example, the determination with cyan ink having similar characteristics can be appropriately executed.

The amount of light in the ink detection region in the present embodiment may be the pixel data itself in the ink detection region or the difference between the pixel data based on the ink non-detection region. As described above, the pixel data in the ink non-detection region is information corresponding to the wall surface of the ink tank 310, and is less affected by the type of ink IK. Therefore, the amount of light in the ink detection region may be obtained based on the amount of light in the ink non-detection region. In this case, the determination of whether or not the amount of light in the ink detection region is equal to or less than the threshold value can be realized by determining whether or not the difference value of the pixel data is equal to or greater than the predetermined threshold value. That is, the magnitude relationship in the threshold value determination can be appropriately changed according to the expression of the amount of light.

Further, in the processing unit 120, when the R light amount is _{equal to} or less than the threshold Th C_R, the G light amount is _{equal to} or less than the threshold Th C_G, and the B light amount is _{larger than the threshold Th C_B at the position} where the ink IK exists, the ink IK is cyan ink. Is determined to be. Similar to the example of black ink, Th _{C_R} and Th _{C_G} are set to values larger than the expected light intensity value by Δ. Further, the threshold value Th _{C_B} is set to a value smaller than the expected value of the amount of light by Δ. For example, (Th _{C_R} , Th _{C_G} , Th _{C_B} ) = (50, 50, 50).

Further, in the processing unit 120, when the R light amount is _{larger than the threshold Th M_R} , the G light amount is _{equal to} or less than the threshold Th M_G, and the B light amount is _{equal to} or less than the threshold Th M_B at the position where the ink IK exists, the ink IK is magenta ink. Is determined to be. For example, (Th _{M_R} , Th _{M_G} , Th _{M_B} ) = (130, 50, 70). In consideration of common judgment with other ink colors, Th _{M_B} = 50 may be used.

Further, in the processing unit 120, when the R light amount is _{larger than the threshold Th Y_R} , the G light amount is larger than the threshold Th Y_G, and the B light amount is _{equal to or less than the threshold Th Y_B at} the position where the ink IK exists, the ink is yellow ink. Is determined. For example, (Th _{Y_R} , Th _{Y_G} , Th _{Y_B} ) = (220, 100, 50).

Further, in the processing unit 120, when the amount of light at the position where the ink IK exists is larger than the amount of light at the position where the ink IK does not exist in at least two of the amount of R light, the amount of G light, and the amount of B light, the ink IK is white ink. Judge that there is. In this case, the processing unit 120 obtains the value of the amount of light in the ink non-detection region as a reference value, and determines whether or not the amount of light exceeds the reference value at a position on the −Z side of the value.

In addition, instead of actually measuring the reference value, the value assumed from the design may be set in advance. For example, the processing unit 120 is greater than the threshold value _{Th W_R} R light quantity is larger G light amount than the threshold value _{Th W_G,} if B amount is greater than the threshold _{Th W_B,} determines that the ink IK is white ink. For example, (Th _{Y_R} , Th _{Y_G} , Th _{Y_B} ) = (220, 220, 220).

The processing unit 120, at a position where the ink IK exists, larger than R light amount threshold value _{Th CL_R,} greater than the threshold value _{Th CL_G} G light amount, if B amount is greater than the threshold _{Th CL_B,} ink IK is a clear ink Is determined. For example, (Th _{CL_R} , Th _{CL_G} , Th _{CL_B} ) = (50, 50, 50).

Since the white ink also satisfies this condition, the white ink is identified by performing the above determination regarding the white ink in advance, or in the determination of the clear ink, two types, a lower limit side threshold value and an upper limit side threshold value, are used. It is desirable to set. For example, the processing unit 120 sets the lower limit side threshold value 50 and the upper limit side threshold value 150, and determines that the ink IK is clear ink when each of the RGB light amounts is between the lower limit side threshold value and the upper limit side threshold value. Further, for ink IK other than clear ink, if the assumed value is an intermediate value, the lower limit side threshold value and the upper limit side threshold value may be set. For example, for the amount of B light of cyan ink, the upper limit side threshold value 150 may be set in addition to the lower limit side threshold value 50. Regarding the amount of R light of magenta ink, the upper limit side threshold value 220 may be set in addition to the lower limit side threshold value 130. Regarding the amount of G light of the yellow ink, the upper limit side threshold value 200 may be set in addition to the lower limit side threshold value 100.

As described above, the processing unit 120 determines whether the ink IK to be determined is the first ink color based on the first ink color threshold corresponding to the first ink color, and corresponds to the second ink color. Based on the second ink color threshold, it may be determined whether the ink IK to be determined is the second ink color. That is, in the determination based on the first ink color threshold value, only the ink of the first ink color satisfies the condition, and the inks of other colors do not satisfy the condition. Therefore, the ink type can be determined by performing the determination using the threshold value according to the ink color.

In this embodiment, as described above, light having a plurality of wavelength bands is used. Therefore, the first ink color threshold includes the threshold Th11 used for comparison with the first light amount and the threshold Th12 used for comparison with the second light amount, and the second ink color threshold is compared with the first light amount. Includes a threshold Th21 used in the above and a threshold Th22 used for comparison with the second light intensity. When the first ink color is black, the threshold Th11 is, for example, Th _{Bk_R} , and the threshold Th12 is, for example, Th _{Bk_G} . Further, as described above, the threshold value such as Th11 is not limited to one value, and may include a lower limit side threshold value and an upper limit side threshold value. Further, the values of the above-mentioned threshold values are examples, and various modifications can be made for specific numerical values.

As described above, in order to perform proper printing, it is important to detect whether or not a given ink tank 310 is filled with an inappropriate type of ink IK. For example, in the case of the ink tank 310 for black ink, it is sufficient if it is possible to detect whether or not ink other than black ink is filled, and it may not be necessary to specify a specific ink color. Therefore, the processing unit 120 performs an ink color determination for determining whether or not the ink to be determined is the predicted ink color based on the threshold value set corresponding to the predicted ink color. This ink color determination is started, for example, when it is detected in the ink amount determination that the ink amount has increased beyond the range assumed to be an error.

FIG. 34 is a flowchart illustrating the ink color determination in this case. When this process is started, the processing unit 120 acquires the R light amount, the G light amount, and the B light amount by controlling the light source 323 and the sensor 190 (S301). Further, the processing unit 120 specifies the predicted ink color (S302). The ink tank 310 read by the photoelectric conversion device 322 is known, and the ink color to be filled in the ink tank 310 is also known in terms of design. When the photoelectric conversion device 322 is mounted on the ink tank 310, the relationship between the photoelectric conversion device 322 and the ink tank 310 is fixed at the time of design. Further, as will be described later with reference to FIGS. 38 and 39, even when the positional relationship between the photoelectric conversion device 322 and the ink tank 310 changes, the photoelectric conversion device 322 and the photoelectric conversion device 322 are based on the control information of the drive mechanism such as the carriage. It is possible to determine the relationship of the ink tank 310.

Next, the processing unit 120 branches the processing based on the predicted ink color (S303). When the predicted ink color is black, the processing unit 120 determines whether or not the ink is black ink (S304). The determination of whether or not the ink is black ink is specifically a threshold value determination using _{Th Bk_R} , Th _{Bk_G} , and Th _{Bk_B.} Similarly, when the predicted ink color is cyan, the processing unit 120 determines whether or not the predicted ink color is cyan (S305). When the predicted ink color is magenta, it is determined whether or not it is magenta ink (S306). When the predicted ink color is yellow, it is determined whether or not the ink is yellow ink (S307). When the predicted ink color is white, it is determined whether or not the ink is white ink (S308). When the predicted ink color is clear, it is determined whether or not the ink is clear ink (S309). Further, when it is determined that the ink color is not the predicted ink color in the determinations of S304 to S309, the processing unit 120 sets the error flag to ON.

Next, the processing unit 120 determines whether or not the error flag is on (S310). If the error flag is on (Yes in S310), it is determined that the given ink tank 310 is filled with improper ink IK. Therefore, the processing unit 120 performs a process of notifying the user to that effect (S311). When the error flag is off (No in S310), the processing ends without performing the notification processing.

FIG. 35 is another flowchart illustrating the ink color determination process. When this process is started, the processing unit 120 acquires the R light amount, the G light amount, and the B light amount (S401). The processing of S401 is the same as that of S301 of FIG.

The processing unit 120 determines whether or not the ink IK to be determined is black ink (S402). The processing of S402 is the same as that of S304. When it is determined that the ink IK is black ink (Yes in S402), the processing unit 120 ends the ink color determination process.

When it is determined that the ink IK is not black ink (No in S402), the processing unit 120 determines whether or not the ink IK to be determined is cyan ink (S403). The processing of S403 is the same as that of S305. When it is determined that the ink IK is cyan ink (Yes in S403), the processing unit 120 ends the ink color determination process.

Hereinafter, the processing unit 120 sequentially determines whether or not the ink IK is magenta ink, yellow ink, white ink, or clear ink (S404 to S407), and processes at the stage where it is determined to be any ink color. To finish. The order of processing of S402 to S407 is not limited to the example shown in FIG. 35, and various modifications can be performed.

By performing the process shown in FIG. 35, it is possible not only to determine whether or not the ink IK is the predicted ink color, but also to specify a specific ink color. If No is determined in any of S402 to S407, it means that the ink color could not be specified. Therefore, the processing unit 120 finishes the process after performing the process of notifying the error (S408).

As shown in FIGS. 34 and 35, the ink color determination process in the present embodiment may be a determination process of whether or not the ink IK to be determined is the predicted ink color, or a specific ink. It may be a color specifying process.

4.3 Modifications In the above, an example in which the R light amount, the G light amount, and the B light amount are the minimum value, the average value, or the like of the pixel data in the ink detection region has been described. That is, the amount of light is one numerical data, and the ink color determination process is a comparison process between the numerical data and the threshold value. However, the amount of light in this embodiment may be a set of a plurality of pixel data in the ink detection region. For example, the processing unit 120 performs comparison processing with the above threshold value for each pixel data of a plurality of pixel data. Then, the ink color of the ink IK to be determined is determined based on whether or not the pixel data of a predetermined ratio or more satisfies the condition.

Alternatively, the amount of light may be waveform information including a plurality of pixel data in the ink detection region. For example, the storage unit 140 stores reference waveform information for each color of ink IK. The reference waveform information is waveform information assumed for the ink IK of the corresponding color. For example, the reference waveform information of black ink is set based on the waveform information actually measured for black ink. The processing unit 120 may determine the ink color of the ink IK to be determined by comparing the waveform information acquired from the sensor 190 with the reference waveform information for each ink color. Here, the waveform information is a set of a plurality of pixel data in the ink detection region. The entity can express numbers by enumeration or mathematical formulas, but it is called waveform information because it looks like a wave when graphed as shown in FIGS. 27 to 33.

Further, in the above, an example in which a comparison process using a threshold value corresponding to the predetermined ink color is performed in order to determine whether or not the ink color is a predetermined color has been described. In this case, a threshold value for black ink, a threshold value for cyan ink, and the like are individually set, and each threshold value includes a threshold value for comparison with the amount of R light, a threshold value for comparison with the amount of G light, and a threshold value for comparison with the amount of B light. In other words, the method of making a judgment based on the ink color has been described.

However, the method of this embodiment is not limited to this. The processing unit 120 performs a comparison process using the first light amount and the first light amount threshold value including a plurality of threshold values having different values, so that the first light amount characteristic is any of the characteristics of 3 or more. You may classify whether there is. Similarly, by performing a comparison process using the second light amount and the second light amount threshold value including a plurality of threshold values having different values, which of the three or more characteristics the second light amount characteristic is. To classify. Then, the processing unit 120 determines the ink color based on the combination pattern of the first light quantity characteristic and the second light quantity characteristic. When the third light is used, the processing unit 120 performs a comparison process using the third light amount and the third light amount threshold value including a plurality of threshold values having different values, so that the third light amount characteristic is 3 or more. Classify which of the characteristics it is. Then, the ink color determination is performed based on the combination pattern of the first to third light intensity characteristics.

For example, in view of FIGS. 28 to 33, four characteristics are set as each light quantity characteristic. The first characteristic is a characteristic in which the difference between the pixel data in the ink detection region and the pixel data in the ink non-detection region is very large, such as the amount of R light of black ink. For example, the pixel data in the ink detection region is in the vicinity of 0, and the pixel data in the ink non-detection region is in the vicinity of 200. It can be said that such a light amount characteristic is suitable for the ink amount detection process because the value change range is large in the vicinity of the liquid surface. Regarding the B light amount of black ink and the B light amount of magenta ink, the pixel data in the ink detection area does not decrease to 0, but since the difference from the ink non-detection area is sufficiently large, those light amount characteristics are included in the first characteristic. ..

The second characteristic is a characteristic in which the difference between the pixel data in the ink detection region and the pixel data in the ink non-detection region is very small, such as the R light amount of magenta ink. For example, the pixel data in the ink detection region and the pixel data in the ink non-detection region are both in the vicinity of 200. Such a light amount characteristic is not suitable for the ink amount detection process because the range of change in the value near the liquid surface is small. The G light amount of the yellow ink is a value of about 150 for the pixel data in the ink detection region, but the value of the ink non-detection area is also a value of about 160 to 170. Therefore, the G light amount characteristic of the yellow ink is the second characteristic. is there.

The third characteristic is a characteristic in which the difference between the pixel data in the ink detection region and the pixel data in the ink non-detection region is an intermediate value, such as the amount of B light of cyan ink. For example, the difference between the pixel data in the ink detection region and the pixel data in the ink non-detection region is about 100. Since the range of change in the value of such a light amount characteristic is medium in the vicinity of the liquid surface, the ink amount detection process is possible, but it is difficult to determine with higher accuracy than the first characteristic.

The fourth characteristic is that the pixel data in the ink detection region has a larger value than the pixel data in the ink non-detection region. The fourth characteristic corresponds to the case where the reflectance of the ink IK becomes very high. For example, the R light intensity characteristic of the yellow ink and each light intensity characteristic of the white ink are the fourth characteristics.

FIG. 36 is a diagram showing the relationship between the ink color, the wavelength band of light, and the light amount characteristic. In FIG. 36, ◯ represents the first characteristic, × represents the second characteristic, Δ represents the third characteristic, and * represents the fourth characteristic.

As shown in FIG. 36, in the black ink, all of the R light amount characteristic, the G light amount characteristic, and the B light amount characteristic are ◯. The cyan ink has an R light quantity characteristic and a G light quantity characteristic of ◯, and a B light quantity characteristic of Δ. The magenta ink has an R light quantity characteristic of x, and a G light quantity characteristic and a B light quantity characteristic of ◯. The yellow ink has an R light intensity characteristic of *, a G light intensity characteristic of ×, and a B light intensity characteristic of ◯. The white ink has all of the R light amount characteristic, the G light amount characteristic, and the B light amount characteristic *. In the clear ink, all of the R light amount characteristic, the G light amount characteristic, and the B light amount characteristic are Δ.

As can be seen from FIG. 36, the black, cyan, magenta, yellow, white, and clear inks do not overlap with each other in the combination patterns of the three light intensity characteristics of RGB. Therefore, the processing unit 120 can obtain a combination pattern of light quantity characteristics for the ink IK to be determined, and can determine the ink color based on the determination of which pattern in FIG. 36 the pattern matches.

For example, the processing unit 120 obtains the absolute difference between the pixel data in the ink non-detection region and the pixel data in the ink detection region as the amount of light. Then, when the amount of light is greater than 150, it is determined to be the first characteristic, and when it is greater than 50 and 150 or less, it is determined to be the third characteristic. When the amount of light is 50 or less, the magnitude relationship between the pixel data in the ink detection region and the pixel data in the ink non-detection region is determined. The processing unit 120 determines that the second characteristic is when the pixel data in the ink detection region is relatively small, and determines that the fourth characteristic is when the pixel data in the ink detection region is relatively large. In this case, the plurality of thresholds included in the first light intensity threshold are 50 and 150. Similarly, the plurality of thresholds included in the second light intensity threshold are also 50 and 150. However, the specific numerical value of the threshold value can be modified in various ways. Further, the plurality of thresholds included in the first light amount threshold value and the plurality of threshold values included in the second light amount threshold value do not have to match. For example, the threshold value for determining the R light intensity characteristic and the threshold value for determining the G light intensity characteristic may be different.

Further, although an example in which the pixel data in the ink detection region based on the pixel data in the ink non-detection region is used as the light amount has been described here, the pixel data in the ink detection region may be used as it is as the light amount. For example, the processing unit 120 sets three thresholds of 50, 150, and 220 as the first light intensity threshold. Then, the processing unit 120 determines that the value of the pixel data in the ink detection region is 50 or less as the first characteristic, if it is larger than 50 and 150 or less, it is determined as the third characteristic, and if it is larger than 150 and 220 or less. If it is larger than 220, it is determined to be the fourth characteristic. Similarly, for the second light amount threshold value and the third light amount threshold value, the light amount characteristic may be determined based on the three threshold values.

Further, as can be seen from FIG. 36, even if Δ is replaced with ×, the combination patterns of the light intensity characteristics do not overlap with each other. Therefore, the processing unit 120 may classify the light quantity characteristics into three without distinguishing between the second characteristic and the third characteristic. Similarly, even if * is replaced with x, the combination patterns of the light intensity characteristics do not overlap. Therefore, the processing unit 120 may classify the light quantity characteristics into three without distinguishing between the second characteristic and the fourth characteristic.

Further, in the above, an example in which the ink type determination is performed after acquiring all the RGB light amounts has been described. However, this can also be modified. In the following, in order to simplify the explanation, a process of determining the ink color for four colors of black, cyan, magenta, and yellow will be described.

FIG. 37 is another flowchart illustrating the ink color determination process. When this process is started, the process unit 120 acquires the amount of R light (S501). In S501, the light emission control of the red LED 323R corresponding to R is performed, and the light emission control of the green LED 323G and the blue LED 323B is unnecessary. The processing unit 120 makes a determination using the amount of R light (S502). The process of S502 is, for example, the determination of the light quantity characteristic using FIG. 36, and in a narrow sense, the determination of whether or not it is the first characteristic.

When the R light intensity characteristic is the first characteristic (Yes in S502), the ink IK to be determined is determined to be black or cyan. Therefore, the processing unit 120 acquires the amount of B light (S503). In S503, the light emission control of the blue LED 323B is performed, and the light emission control of the red LED 323R and the green LED 323G is unnecessary. The processing unit 120 makes a determination using the amount of B light (S504). When the B light intensity characteristic is the first characteristic (Yes in S504), the processing unit 120 determines that the ink IK to be determined is black ink (S505). When the B light intensity characteristic is not the first characteristic (No in S504), the processing unit 120 determines that the ink IK to be determined is cyan ink (S506).

When the R light intensity characteristic is not the first characteristic (No in S502), the ink IK to be determined is determined to be magenta or yellow. Therefore, the processing unit 120 acquires the amount of G light (S507). In S507, the light emission control of the green LED 323G is performed, and the light emission control of the red LED 323R and the blue LED 323B is unnecessary. The processing unit 120 makes a determination using the amount of G light (S508). When the G light intensity characteristic is the first characteristic (Yes in S508), the processing unit 120 determines that the ink IK to be determined is magenta ink (S509). When the G light intensity characteristic is not the first characteristic (No in S508), the processing unit 120 determines that the ink IK to be determined is cyan ink (S510).

In the process shown in FIG. 37, two lights having different wavelength bands may be emitted before the ink color is determined. Compared with the case of acquiring the light amounts of all three colors of RGB, the time required for the light emission of the light source 323 and the output of the pixel data by the sensor 190 can be reduced, so that the ink color determination process can be speeded up. In FIG. 37, an example in which the R light amount is first determined and then the G light amount or the B light amount is determined has been described, but it is easy to understand that various modifications can be performed in the determination order. Further, the determination of S502, S504, and S508 may be any process as long as the difference between the ink colors can be identified, and is not limited to the above-mentioned light intensity characteristic determination using FIG. 36.

Further, in the present embodiment, the light source 323 used for the ink amount detection process may be determined based on the ink type. Specifically, when the ink IK of any one of black ink, cyan ink, magenta ink, and yellow ink is targeted, the light source 323 whose light amount characteristic is the first characteristic is used for the ink amount detection process. As described above, the difference between the first characteristic and the pixel data between the ink detection region and the ink non-detection region is large. Therefore, by using the pixel data of the first characteristic, it is possible to increase the accuracy of the ink amount detection process as compared with the case of using the pixel data of other characteristics.

An example of combining the process of FIG. 37 and the ink amount detection process will be described. When it is determined that the ink IK to be determined is black ink (S505), the processing unit 120 performs ink amount detection processing based on the pixel data of R acquired in S501 or the pixel data of B acquired in S503. I do. Since the light amount characteristic of all RGB is the first characteristic of the black ink, the processing unit 120 can use the pixel data of any color for the ink amount detection process. Here, R or B is used in consideration of using the acquired pixel data.

When it is determined that the ink IK to be determined is cyan ink (S506), the processing unit 120 performs the ink amount detection process based on the pixel data of R acquired in S501. When it is determined that the ink IK to be determined is magenta ink (S509), the processing unit 120 performs the ink amount detection process based on the pixel data of G acquired in S507.

When it is determined that the ink IK to be determined is yellow ink (S510), the processing unit 120 performs the ink amount detection process based on the pixel data of B. However, since the B light amount has not been acquired at the stage of S510, the processing unit 120 acquires the B light amount by controlling the light emission of the blue LED 323B, and then performs the ink amount detection process based on the acquired B pixel data.

5. Notification using the light source of the center unit In the above, an example in which the light source 323 included in the sensor unit 320 is used for the ink amount detection process or the ink type determination process has been described. That is, the light source 323 irradiates light toward the side surface of the ink tank 310. However, it is possible to provide the light source 323 with these other functions as well.

For example, the electronic device 10 which is a printing device includes an ink tank 310, a print head 107, a light source 323, a sensor 190, and a processing unit 120, as well as a light guide 112 that guides light from the light source 323 to the outside of a housing. It may be. The housing here is a member that houses each part of the printing apparatus. For example, the electronic device 10 includes a housing that houses an ink tank 310, a print head 107, a light source 323, a sensor 190, and a processing unit 120. The housing here corresponds to the case portion 102 of the printer unit 100, but the housing may include the case portion 201 of the scanner unit 200, the case portion 301 of the ink tank unit 300, and the like. Further, the light guide body 324 described above with reference to FIG. 6 guides the light from the light source 323 to the outside of the sensor unit 320, and is different from the light guide body 112 that guides the light from the light source 323 to the outside of the housing. .. For example, the light from the light source 323 enters the light guide body 112 via the light guide body 324, and is guided to the outside of the housing by the light guide body 112.

In this way, the light source 323 used for the ink amount detection process and the ink type determination process can be diverted to other uses. Specifically, the light source 323 is used to visually notify the state of the printing apparatus. For example, it is possible to urge the user to take appropriate measures by notifying the amount of ink based on the light emission of the light source 323 and notifying the occurrence of an error or the like. In this way, it is not necessary to provide a light source dedicated to notification separately from the light source 323, so that the cost of the printing apparatus can be reduced.

38 and 39 are perspective views illustrating the positional relationship between the ink tank 310, the sensor unit 320 including the light source 323, and the light guide 112 in the printing apparatus of the present embodiment. As shown in FIGS. 38 and 39, the light guide 112 and the ink tank 310 are aligned in the first direction. The first direction here is, for example, the ± X direction, which corresponds to the main scanning axis HD of the printing apparatus. Here, five ink tanks 310a to 310e are illustrated as the ink tanks 310. For example, the light guide 112, the ink tank 310a, the ink tank 310b, the ink tank 310c, the ink tank 310d, and the ink tank 310e are arranged side by side in this order along the + X direction.

Further, the light source 323 is provided at a position in the −Y direction with respect to the ink tank 310 and the light guide body 112, and irradiates the side surface of the ink tank 310 or the light guide body 112 on the −Y direction side with light. Here, as shown in FIGS. 38 and 39, the light source 323 and the sensor 190 may move relative to the ink tank 310 and the light guide 112 in the first direction.

As described above with reference to FIG. 9, the sensor unit 320 may be fixed to the side surface of the ink tank 310 in consideration of the ink amount detection process. However, if that state is maintained, it is difficult to guide the light from the light source 323 to the outside of the housing by using the light guide 112. On the other hand, when the ink tank 310, the light guide 112, and the sensor unit 320 can move relative to each other along the X-axis direction, the X-axis of the light guide 112 and the sensor unit 320 is shown in FIG. 38. It is possible to switch between a state in which the positions of the ink tanks 310 and the sensor unit 320 overlap in the X-axis as shown in FIG. 39. In the state shown in FIG. 38, the light from the light source 323 is incident on the light guide 112. Therefore, by extending the light guide body 112 to the vicinity of the housing, the light of the light source 323 can be guided to the outside of the housing. In the state shown in FIG. 39, the light from the light source 323 is incident on the side surface of the ink tank 310. Therefore, the above-mentioned ink amount detection process and ink type determination process can be performed.

Furthermore, it is also possible to control switching between a state in which the positions of the ink tank 310a and the sensor unit 320 overlap on the X-axis and a state in which the positions of the ink tank 310b and the sensor unit 320 overlap on the X-axis. Therefore, it is also possible to use a small number of sensor units 320, or in a narrow sense, one sensor unit 320, to execute ink amount detection processing and ink type determination processing for a plurality of ink tanks 310.

FIG. 40 is a diagram for explaining the positional relationship of each part when the ink tank 310, the light guide body 112, and the sensor unit 320 are observed from the + Z direction. As shown in FIG. 40, the printing apparatus further includes a carriage 106 that includes an ink tank 310 and moves relative to the housing. That is, the carriage 106 has an ink tank 310 and a print head 107, and can move in the main scanning direction with the ink tank 310 and the print head 107 mounted therein. In this way, the positional relationship between the ink tank 310 and the light source 323 can be adjusted by controlling the carriage 106 to be driven. In this case, the position of the sensor unit 320 with respect to the housing can be fixed, but driving both the carriage 106 and the sensor unit 320 is not hindered. Further, it is not hindered that the light guide body is composed of one member or a plurality of members.

More specifically, the light guide body 112 includes a first light guide body 112-1 mounted on the carriage 106 and a second light guide body 112-2 provided outside the carriage 106 and fixed to a housing. Has. Then, the light that has passed through the first light guide body 112-1 is emitted to the outside of the housing via the second light guide body 112-2. By mounting the first light guide body 112-1 on the carriage 106, it is possible to adjust the positional relationship between the light guide body 112 and the sensor unit 320 on the X axis. That is, as shown in FIG. 38, it is possible to realize a state in which the light of the light source 323 is incident on the light guide body 112. Further, by fixing the second light guide body 112-2, the portion of the light guide body 112 to be moved can be limited. When the entire light guide body 112 moves, it is necessary to open a large space as a movement path in order to suppress collision with other members. On the other hand, by fixing the second light guide body 112-2 to the housing, it is possible to suppress the increase in size of the printing apparatus.

As shown in FIG. 40, in a state where the light from the light source 323 is guided to the outside of the housing, the light source 323, the first light guide body 112-1, and the second light guide body 112-2 are the first. They are arranged in this order in the second direction that intersects the directions. The second direction is a direction along the Y axis and corresponds to the sub-scanning axis VD. The second direction is specifically the + Y direction. In this way, the light from the light source 323 is guided in the order of the first light guide body 112-1 and the second light guide body 112-2, so that the light can be appropriately guided to the outside of the housing. It will be possible.

The printing device includes a light guide body 112 and an indicator including a window portion. That is, by making a part of the housing a translucent window portion, the light from the light source 323 guided by the light guide 112 can be emitted to the outside of the housing. Hereinafter, an example in which the window portion transmits the light without changing the wavelength band of the light emitted from the light source 323 will be described. For example, when the light source 323 emits the red LED 323R, the indicator emits red. However, the method of the present embodiment is not limited to this, and the light from the light source 323 may be subjected to some sort of filtering, and the light after the filtering may be emitted to the outside of the housing. Further, the light from the light source 323 may be used as a backlight for a liquid crystal display or the like. Further, the window portion may be a translucent member or an opening provided in the housing.

The processing unit 120 controls the light guided to the outside by the light guide 112 based on the state of the printing apparatus. In this way, it is possible to appropriately notify the user of the state of the printing device. Specifically, the state here is an error state of the printing apparatus or an ink IK state in the ink tank. The state of ink IK is specifically a state corresponding to ink low or ink full. As the error represented by the error state, various errors such as ejection failure of the print head 107, paper jam, ink leakage, motor failure, and pump failure are assumed. The error state is a state in which printing cannot be executed, or a state in which printing may not be executed unless the user takes corrective action. Therefore, it is important to notify the error status. Ink low is a state in which a defect of the print head 107 may occur due to running out of ink, and ink full is a state in which ink leakage may occur due to further replenishment. Even in these cases, the printing device can be operated appropriately by notifying the user.

The notification control according to the state may be, for example, control relating to a light source of any color included in the light source 323. In this case, the processing unit 120 controls the state by turning on, off, blinking, or the like of the light source. The processing unit 120 may notify the state in an identifiable manner by adjusting the blinking interval and the like.

Alternatively, the light source 323 may irradiate light of a plurality of colors. The processing unit 120 controls the light according to the state based on the light emission pattern of the light of a plurality of colors. As described above, in the ink amount detection process and the ink type determination process, for example, three colors of RGB light are irradiated. Therefore, the processing unit 120 may control not only the light emission timing such as lighting, extinguishing, and blinking, but also the light emitting color of the indicator. For example, the processing unit 120 adjusts the amount of light by PWM (Pulse Width Modulation) control to mix the light in each wavelength band of RGB, thereby causing the indicator to emit light in the ink color to be notified.

FIG. 41 is a diagram illustrating color mixing of light. As shown in FIG. 41, the processing unit 120 controls the pulse width of the control signal of the red LED 323R, the pulse width of the control signal of the green LED 323G, and the pulse width of the control signal of the blue LED 323B, thereby intensifying the intensity of each color of RGB. To adjust. In the example of FIG. 41, the light from the light source 323 can be made yellow light by increasing the intensity of the R light and the G light and not emitting the B light. For example, when it is determined that the yellow ink is ink low or ink full, the processing unit 120 controls the indicator to emit yellow light. For example, the processing unit 120 controls to turn on the indicator in yellow when the yellow ink is determined to be ink low, and controls to blink the indicator in yellow when the yellow ink is determined to be ink full. In this way, in a printing apparatus using ink IK of a plurality of colors, it is possible to notify the state of the ink IK in an easy-to-understand manner.

Further, the method of the present embodiment includes an ink tank 310, a print head 107, a light source 323, a sensor 190, and a processing unit 120, and the processing unit 120 controls the light source 323 according to the state of the printing apparatus. This can be applied to a printing device that performs a process of notifying the user of the state. That is, the printing apparatus of the present embodiment may have a configuration capable of executing notification using the light of the light source 323, and the configuration is not limited to the light guide 112. It can also be applied to a so-called off-carry type printing apparatus in which an ink tank is provided on the outside of a carriage. In this case, the light source 323 may move to a position opposite to the light guide body fixed to the housing so as to line up with the ink tank, so that the notification using light can be executed.

6. Multifunction device The electronic device 10 according to the present embodiment may be a multifunction device having a printing function and a scanning function. FIG. 42 is a perspective view showing a state in which the case portion 201 of the scanner unit 200 is rotated with respect to the printer unit 100 in the electronic device 10 of FIG. In the state shown in FIG. 42, the platen 202 is exposed. The user sets the original to be read on the platen 202, and then uses the operation unit 160 to instruct the scan to be executed. The scanner unit 200 reads the image of the original by performing the reading process while moving the image reading unit (not shown) based on the user's instruction operation. The scanner unit 200 is not limited to the flatbed type scanner. For example, the scanner unit 200 may be a scanner having an ADF (Auto Document Feeder) (not shown). Further, the electronic device 10 may be a device having both a flatbed type scanner and a scanner having an ADF.

The electronic device 10 includes an image reading unit including a first sensor module, an ink tank 310, a print head 107, a second sensor module, and a processing unit 120. The image reading unit reads a document using a first sensor module including m (integer of 2 or more) linear image sensor chips. The second sensor module includes n (n is 1 or more, an integer of n <m) linear image sensor chips, and detects light incident from the ink tank 310. The processing unit 120 detects the amount of ink in the ink tank based on the output of the second sensor module. The first sensor module is a sensor module used for scanning an image in the scanner unit 200, and the second sensor module is a sensor module used for ink amount detection processing in the ink tank unit 300.

Both the first sensor module and the second sensor module include a linear image sensor chip. The specific configuration of the linear image sensor chip is the same as that of the photoelectric conversion device 322 described above, and is a chip in which a plurality of photoelectric conversion elements are arranged side by side in a predetermined direction. Since the linear image sensor used for image reading and the linear image sensor used for ink amount detection processing can be shared, it is possible to improve the efficiency of manufacturing the electronic device 10.

However, the first sensor module needs to have a length corresponding to the size of the document to be read. Since the length of one linear image sensor chip is, for example, about 10 mm, the first sensor module needs to include at least two or more linear image sensor chips. On the other hand, the second sensor module has a length corresponding to the target range of ink amount detection. The target range of ink amount detection can be modified in various ways, but is generally shorter than that of image reading. That is, as described above, m is an integer of 2 or more, n is an integer of 1 or more, and m> n. In this way, the number of linear image sensor chips can be appropriately set according to the application.

The difference between the first sensor module and the second sensor module is not limited to the number of linear image sensor chips. The m linear image sensor chips of the first sensor module are provided along the horizontal direction in the longitudinal direction. The n linear image sensor chips of the second sensor module are provided along the vertical direction in the longitudinal direction. Since the second sensor module needs to detect the liquid level of the ink IK as described above, the longitudinal direction is the vertical direction.

On the other hand, in consideration of reading the image of the original, the longitudinal direction of the first sensor module needs to be the horizontal direction. This is because when the longitudinal direction of the first sensor module is set to the vertical direction, it is difficult to stably set the original on the platen 202, or it is difficult to stabilize the original posture when the original is conveyed by the ADF. By setting the longitudinal direction of the linear image sensor chip according to the application, it becomes possible to appropriately execute the ink amount detection process and the image reading.

Further, the first sensor module operates at the first operating frequency, and the second sensor module operates at the second operating frequency lower than the first operating frequency. In image reading, it is necessary to continuously acquire signals corresponding to a large number of pixels and perform A / D conversion processing, correction processing, etc. of the signals to form image data. Therefore, it is desirable that the reading by the first sensor module be performed at high speed. On the other hand, the ink amount detection is less likely to be a problem even if the number of photoelectric conversion elements is small and it takes a certain amount of time to detect the ink amount. By setting the operating frequency for each sensor module, each sensor module can be operated at an appropriate speed.

As described above, the printing apparatus of the present embodiment includes an ink tank, a printing head, a light source, a sensor, a processing unit, and a light guide body. The print head prints using the ink in the ink tank. The light source irradiates the ink tank with light. The sensor detects the light incident from the ink tank side during the period when the light source emits light and outputs the pixel data. The processing unit determines the amount of ink based on the output of the sensor. The light guide guides the light from the light source to the outside of the housing.

In this way, the light of the light source used for determining the amount of ink can be guided to the outside of the housing. Since the light source for the ink amount detection process can be diverted to the notification process and the like, the cost can be reduced.

Further, the light guide body and the ink tank of the present embodiment are arranged in the first direction, and the light source and the sensor may move relative to the ink tank and the light guide body in the first direction.

In this way, it is possible to switch between a state in which the amount of ink can be detected using the light source and a state in which the light of the light source is guided to the outside of the housing.

Further, the printing apparatus of the present embodiment may further include a carriage that is equipped with an ink tank and moves with respect to the housing.

In this way, it is possible to switch between a state in which the amount of ink can be detected using the light source and a state in which the light of the light source is guided to the outside of the housing based on the drive of the carriage.

Further, the light guide body of the present embodiment has a first light guide body mounted on the carriage and a second light guide body provided outside the carriage and fixed to the housing, and the first light guide body is provided. The light that has passed may be emitted to the outside of the housing via the second light guide body.

In this way, the light guide body to be moved while switching between a state in which the amount of ink can be detected using a light source and a state in which the light of the light source is guided to the outside of the housing based on the drive of the carriage. It becomes possible to suppress the size of the.

Further, in the present embodiment, the light source, the first light guide body, and the second light guide body may be arranged in the order of the light source, the first light guide body, and the second light guide body in the second direction where the light source, the first light guide body, and the second light guide body intersect in the first direction. Good.

In this way, it is possible to appropriately guide the light of the light source to the outside of the housing by using the first light guide body and the second light guide body.

Further, the processing unit of the present embodiment may control the light guided to the outside by the light guide based on the state of the printing apparatus.

In this way, it is possible to notify the state of the printing apparatus by using the light source for the ink amount detection process.

Further, the light source of the present embodiment irradiates light of a plurality of colors, and the processing unit may control the light according to the state based on the emission pattern of the light of the plurality of colors.

In this way, various notification processes can be performed using the light source for the ink amount detection process.

Further, the state of the present embodiment may be an error state of the printing apparatus or a state of ink in the ink tank.

In this way, it is possible to appropriately notify the state that needs to be dealt with by the user.

Further, the light guide body of the present embodiment and an indicator including a window portion may be further included.

In this way, it is possible to realize notification using a light source with an efficient configuration.

Further, the printing apparatus of this embodiment includes an ink tank, a printing head, a light source, a sensor, and a processing unit. The print head prints using the ink in the ink tank. The light source irradiates the ink tank with light. The sensor detects the light incident from the ink tank side during the period when the light source emits light and outputs the pixel data. The processing unit determines the amount of ink based on the output of the sensor. Then, the processing unit controls the light source according to the state of the printing device to notify the user of the state.

In this way, the light source used for determining the amount of ink can be diverted to the notification process, so that the cost can be reduced.

Further, the sensor of the present embodiment may include a photoelectric conversion device and an AFE (Analog Front End) circuit connected to the photoelectric conversion device.

In this way, it becomes possible to realize a sensor that outputs pixel data, which is digital data.

Further, the photoelectric conversion device of this embodiment may be a linear image sensor.

By using a plurality of photoelectric conversion elements arranged in a predetermined direction in this way, it is possible to accurately detect the amount of ink.

Further, the linear image sensor of the present embodiment may be provided so that the longitudinal direction is along the vertical direction.

By using a plurality of photoelectric conversion elements arranged in the vertical direction in this way, it is possible to accurately detect the amount of ink.

Although the present embodiment has been described in detail as described above, those skilled in the art will easily understand that many modifications that do not substantially deviate from the new matters and effects of the present embodiment are possible. .. Therefore, all such variations are included in the scope of the present disclosure. For example, a term described at least once in a specification or drawing with a different term in a broader or synonymous manner may be replaced by that different term anywhere in the specification or drawing. All combinations of the present embodiment and modifications are also included in the scope of the present disclosure. Further, the configuration and operation of the electronic device, the printer unit, the scanner unit, the ink tank unit, and the like are not limited to those described in the present embodiment, and various modifications can be performed.

For example, in the photoelectric conversion device, the linear image sensor may be arranged horizontally or diagonally from the horizontal direction. In this case, by arranging a plurality of linear image sensors in the vertical direction or moving them in the vertical direction relative to the ink tank, it is possible to obtain the same information as when the linear image sensors are arranged in the vertical direction. .. Further, the photoelectric conversion device may be one or a plurality of area image sensors. By doing so, one image sensor may be straddled over a plurality of ink tanks.

10 ... Electronic equipment, 100 ... Printer unit, 101 ... Operation panel, 102 ... Case, 104 ... Front cover, 105 ... Tube, 106 ... Carriage, 107 ... Print head, 108 ... Paper feed motor, 109 ... Carriage motor, 110 ... Paper feed roller, 111 ... Substrate, 112 ... Light guide, 120 ... Processing unit, 130 ... AFE circuit, 140 ... Storage unit, 150 ... Display unit, 160 ... Operation unit, 170 ... External I / F unit, 190 ... Sensor, 200 ... Scanner unit, 201 ... Case, 202 ... Document stand, 300 ... Ink tank unit, 301 ... Case, 302 ... Lid, 303 ... Hinge, 310, 310a-310e ... Ink tank, 311 ... Note Inlet, 312 ... Discharge port, 313 ... Second discharge port, 314 ... Ink flow path, 315 ... Main container, 320 ... Sensor unit, 321 ... Board, 322 ... Photoelectric conversion device, 3222 ... Control circuit, 3223 ... Boost circuit, 3224 ... Pixel drive circuit, 3225 ... Pixel part, 3226 ... CDS circuit, 3227 ... Sample hold circuit, 3228 ... Output circuit, 323 ... Light source, 323R ... Red LED, 323G ... Green LED, 323B ... Blue LED, 324 ... Light guide Body, 325 ... Lens array, 326 ... Case, 327,328 ... Opening, 329 ... Light blocking wall, CDSC, CPC, DRC ... Control signal, CLK ... Clock signal, Drv, DrvB, DrvG, DrvR ... Drive signal, EN_I , EN_O, EN1 to ENn ... Chip enable signal, HD ... Main scanning axis, VD ... Sub scanning axis, IK, IKa to IKe ... Ink, OP1, OP2 ... Output terminal, OS ... Output signal, P ... Print medium, RS ... Reflective surface, RST ... reset signal, SMP ... sampling signal, SW0 to SW8 ... switch, Tx ... transfer control signal, VDD, VSS ... power supply voltage, VDP, VSS ... power supply terminal, VREF ... reference voltage, VRP ... reference voltage supply terminal

Claims (13)

Ink tank and
A print head that prints using the ink in the ink tank,
A light source that irradiates the ink tank with light,
A sensor that detects light incident from the ink tank side during the period when the light source emits light,
A processing unit that determines the amount of ink based on the output of the sensor,
A light guide that guides the light from the light source to the outside of the housing,
A printing apparatus comprising. In claim 1,
The light guide and the ink tank are arranged in the first direction.
A printing apparatus characterized in that the light source and the sensor move relative to the ink tank and the light guide in the first direction. In claim 2,
A printing apparatus comprising the ink tank and further including a carriage that moves with respect to the housing. In claim 3, the light guide body includes a first light guide body mounted on the carriage and a second light guide body provided outside the carriage and fixed to the housing.
A printing apparatus characterized in that light that has passed through the first light guide body is emitted to the outside of the housing via the second light guide body. In claim 4,
In the second direction in which the light source, the first light guide body, and the second light guide body intersect in the first direction, the light source, the first light guide body, and the second light guide body are arranged in this order. A printing device characterized by the fact that. In any one of claims 1 to 5,
The processing unit is a printing device that controls the light guided to the outside by the light guide based on the state of the printing device. In claim 6,
The light source irradiates light of multiple colors and
The processing unit is a printing apparatus characterized in that the light is controlled according to the state based on the light emission pattern of the plurality of colors of light. In claim 6 or 7,
The printing device is characterized in that the state is an error state of the printing device or a state of the ink in the ink tank. In any one of claims 1 to 8,
A printing apparatus comprising the light guide body and an indicator including a window portion. Ink tank and
A print head that prints using the ink in the ink tank,
A light source that irradiates the ink tank with light,
A sensor that detects light incident from the ink tank side during the period when the light source emits light,
A processing unit that determines the amount of ink based on the output of the sensor,
Including
The processing unit
A printing device characterized in that a process of notifying a user of the state is performed by controlling the light source according to the state of the printing device. In any one of claims 1 to 10,
The sensor is a printing apparatus including a photoelectric conversion device and an AFE circuit connected to the photoelectric conversion device. 11.
The photoelectric conversion device is a printing device characterized by being a linear image sensor. In claim 12,
The linear image sensor is a printing apparatus characterized in that the linear image sensor is provided so that the longitudinal direction is along the vertical direction.