JP2017170879A - Position detector, droplet ejection device, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position detector that is able to reduce the size of a bottom face part.SOLUTION: A position detector that detects the position of an object moved on a transfer surface, the object having the position detector mounted thereon, comprises: movement amount detection means that detects an amount of movement on the transfer surface; posture detection means that detects posture of the object on at least the transfer surface; and position calculating means that calculates the position of the object on the basis of the amount of movement and the posture.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a position detection device, a droplet discharge device, and a program.

  There is known a printer that forms an image by ejecting ink or the like at a timing when the sheet is conveyed and the sheet reaches an image forming position. On the other hand, with the downsizing of notebook PCs and the spread of smart devices, there is an increasing need for downsizing and portability of printers. Therefore, a printer that is reduced in size by deleting the paper transport system from the printer (hereinafter referred to as HMP: Handy Mobile Printer) is being put into practical use. Since the paper transport system is not mounted on the HMP, a person moves on the paper surface to scan the paper surface and eject ink.

  The HMP detects its own position on the paper surface and discharges ink for forming an image corresponding to the position. As a mechanism for detecting this position, an HMP in which two navigation sensors are arranged on the bottom surface is conventionally known (see, for example, Patent Document 1). The navigation sensor is a sensor that optically detects a minute edge of the paper surface and detects a movement amount for each cycle time. Since there are two navigation sensors, the HMP can detect the rotation angle in the direction horizontal to the paper surface.

  However, the conventional HMP has a problem that it is difficult to reduce the size of the bottom surface. First, even if there is only one navigation sensor, the position can be detected. Two are necessary for calculating the rotation angle of the HMP with respect to the paper surface and calculating the position based on the rotation angle. In order to improve the detection accuracy of the rotation angle, it is preferable that the interval between the two navigation sensors is long to some extent. For these reasons, it has been difficult for the conventional HMP to reduce the size of the bottom surface.

  In view of the above problems, an object of the present invention is to provide a position detection device capable of reducing the size of the bottom surface.

  The present invention is a position detection device for detecting a position on a moving surface of a mounted object on which a position detecting device is mounted, the moving amount detecting means for detecting a moving amount on the moving surface, and at least the moving surface on the moving surface. Posture detection means for detecting the posture of the mounted object; and position calculating means for calculating the position of the mounted object based on the movement amount and the posture.

  A position detection device capable of reducing the size of the bottom surface portion can be provided.

It is an example of the figure which shows the outline of a structure of HMP of this embodiment. It is an example of the figure which shows the image formation by HMP typically. It is an example of the hardware block diagram of HMP. It is an example of the figure explaining the structure of a control part. It is an example of the figure explaining the principle in which a gyro sensor detects angular velocity. It is a figure which shows the structural example of the hardware constitutions of a navigation sensor. It is an example of the figure explaining the detection method of the movement amount by a navigation sensor. 3 is an example of a configuration diagram of an IJ recording head driving circuit. FIG. It is an example of the top view of HMP. It is an example of the figure explaining the coordinate system of HMP, and the calculation method of a position. FIG. 6 is an example of a diagram for explaining how to obtain a rotation angle dθ of HMP generated during image formation. It is an example of the figure explaining the relationship between a target discharge position and the position of a nozzle. It is an example of the flowchart figure explaining the operation | movement procedure of an image data output device and HMP. It is an example of the figure explaining the image formation possible range in case the navigation sensor shown for the comparison is two. It is an example of the figure explaining the image formation possible range in case there is one navigation sensor. It is an example of the figure explaining the example of arrangement | positioning of a navigation sensor. It is an example of the figure which shows the example of arrangement | positioning of a gyro sensor. It is an example of the figure explaining the attitude | position of HMP which a gyro sensor detects. It is an example of the figure which shows the change of the resolution of the distance between sensor papers and movement amount. It is an example of the figure explaining the assembly | attachment position of a navigation sensor. It is an example of the figure explaining the floating amount from the printing medium of a navigation sensor. (Example 2) which is an example of the flowchart figure explaining the operation | movement procedure of an image data output device and HMP.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

First, schematic features of the handy mobile printer (hereinafter referred to as HMP) of this embodiment will be described with reference to FIG. FIG. 1 is a diagram showing an outline of the configuration of the HMP 20 of the present embodiment. FIG. 1A shows a configuration diagram of a conventional HMP 20 shown for comparison. The conventional HMP 20 has one IJ recording head 24 and two navigation sensors 30 (hereinafter referred to as navigation sensors S ₀ and S ₁ for distinction).

FIG. 1B shows an image formable range 501 of the conventional HMP 20. The HMP 20 in FIG. 1A has an IJ recording head 24 on the left side, and two navigation sensors S ₀ and S ₁ are arranged vertically on the right side. The distance between the navigation sensor S ₁ and the lower end of the nozzle 61 is A [mm], and the distance from the nozzle 61 to the navigation sensors S ₀ and S ₁ is B [mm]. Since the navigation sensors S ₀ and S ₁ protrude from the print medium 12, the HMP 20 cannot move to the right of B [mm] from the left end of the print medium 12. The navigation sensors _{S 1} and since a distance between lower edge is A nozzle 61 (mm), HMP20 can not move lower than A (mm) from the lower end of the print medium 12. Therefore, as shown in the drawing, a place where printing cannot be performed under or on the printing medium 12 is generated.

FIG.1 (c) shows the block diagram of HMP20 of this embodiment. The HMP 20 of this embodiment has one IJ recording head 24, one navigation sensor S ₀ , and one gyro sensor 31. FIG. 1D shows an image formable range 501 of the HMP 20 of this embodiment. The interval between the lower end and navigation sensors S ₀ of nozzles 61 and A [mm]. Since the navigation sensor S ₀ protrudes from the print medium 12, the HMP 20 cannot move below A [mm] from the lower end of the print medium 12. On the other hand, since the horizontal distance between the nozzle 61 and the navigation sensor S ₀ is zero, the HMP 20 can move from the left end to the right end of the print medium 12. Therefore, as shown in the figure, there is a place where printing cannot be performed only on the lower side.

  As is apparent from a comparison between FIG. 1B and FIG. 1D, the number of navigation sensors can be reduced to one by installing the gyro sensor 31, and the size of the bottom surface can be reduced. As a result, the image formable range 501 can be increased.

<Terminology>
The size of the bottom surface is a range surrounding the navigation sensor and the nozzle 61, or the size of the bottom surface of the HMP 20 that cannot be further reduced by being restricted by this range. The actual size of the bottom surface of the HMP 20 may be larger than the range surrounding the navigation sensor and the nozzle 61, and may be determined in consideration of operability and design.

  The mounted object refers to an object on which a position detection device is mounted. It may be an object whose position can be detected on the moving surface. For example, the HMP 20 is an example of a mounted object. In addition, since the position detection device can detect the distance moved, a distance measuring device can be an example of the mounted object.

  The moving surface only needs to be a surface on which the HMP 20 can move, and includes a curved surface as well as a flat surface. Specific examples include the print medium 12, but the present invention is not limited to this.

  Further, the posture of the object means a degree of freedom representing a rotation angle among the six degrees of freedom of the rigid body (a rotation angle centered on three axes orthogonal to each other through the center of gravity of the rigid body). Among these, the posture of the object in the plane is represented by a rotation angle about an axis perpendicular to the plane.

  The calculation of the position means obtaining information related to the position by performing an operation on some data, and the detection of the position means obtaining information related to the position regardless of the process. However, both are the same in that information about the position can be obtained, and in the present embodiment, position calculation and position detection are not strictly distinguished.

<Image formation by HMP20>
FIG. 2 is an example of a diagram schematically showing image formation by the HMP 20. For example, image data is transmitted to the HMP 20 from an image data output device 11 such as a smartphone or a PC (Personal Computer). The user holds the HMP 20 and scans it freehand so as not to lift up from the print medium 12 (for example, a standard paper or a notebook).

HMP20 detects the position in the navigation sensors S ₀ and a gyro sensor 31 as described later, HMP20 is when you move to the target discharge position, discharging the color inks to be ejected at the target discharge position. Since the place where ink has already been ejected is masked (because it is not an ink ejection target), the user can form an image by scanning the HMP 20 on the print medium 12 in any direction.

It is preferable that the HMP 20 does not float from the print medium 12 because the navigation sensor S ₀ detects the amount of movement using reflected light from the print medium 12. When the HMP 20 is lifted from the print medium 12, the reflected light cannot be detected and the amount of movement cannot be detected. If the navigation sensors S ₀ from the print medium 12 protrudes even, or not be detected reflected light by the thickness of the printing medium 12, which may be able to detect or misaligned. For this reason, the navigation sensor S ₀ is preferably scanned on the print medium 12, and the nozzle 61 and the navigation sensor S ₀ are preferably both present on the print medium 12 as described above.

<Configuration example>
FIG. 3 shows an example of a hardware configuration diagram of the HMP 20. The HMP 20 is an example of a droplet discharge device or an image forming device that forms an image on the print medium 12. The overall operation of the HMP 20 is controlled by the control unit 25, and the communication I / F 27, IJ recording head drive circuit 23, OPU 26, ROM 28, DRAM 29, navigation sensor 30, and gyro sensor 31 are electrically connected to the control unit 25. Has been. Further, since the HMP 20 is driven by electric power, it has a power source 22 and a power source circuit 21. The power generated by the power supply circuit 21 is transmitted through a communication line I / F 27, an IJ recording head drive circuit 23, an OPU 26, a ROM 28, a DRAM 29, an IJ recording head 24, a control unit 25, a navigation sensor 30, and the like. It is supplied to the gyro sensor 31.

  As the power source 22, a battery is mainly used. A solar cell, a commercial power source (AC power source), a fuel cell, or the like may be used. The power supply circuit 21 distributes the power supplied from the power supply 22 to each part of the HMP 20. Further, the voltage of the power supply 22 is stepped down or boosted to a voltage suitable for each part. When the power source 22 is a rechargeable battery, the power source circuit 21 detects the connection of the AC power source and connects it to the battery charging circuit, thereby enabling the power source 22 to be charged.

  The communication I / F 27 receives image data from the image data output device 11 such as a smartphone or a PC (Personal Computer). The communication I / F 27 is a communication device that supports communication standards such as wireless LAN, Bluetooth (registered trademark), NFC (Near Field Communication), infrared, 3G (mobile phone), or LTE (Long Term Evolution). In addition to such wireless communication, a communication device that supports wired communication using a wired LAN, a USB cable, or the like may be used.

  The ROM 28 stores firmware that performs hardware control of the HMP 20, drive waveform data of the IJ recording head 24 (data that defines voltage changes for ejecting droplets), initial setting data of the HMP 20, and the like.

  The DRAM 29 is used for storing image data received by the communication I / F 27 and storing firmware developed from the ROM 28. Therefore, it is used as a work memory when the CPU 33 executes the firmware.

  The navigation sensor 30 is a sensor that detects the amount of movement of the HMP 20 every predetermined cycle time. The navigation sensor 30 includes, for example, a light source such as a light emitting diode (LED) or a laser, and an image sensor that images the print medium 12. When the HMP 20 is scanned on the print medium 12, minute edges of the print medium 12 are detected one after another (imaged), and the amount of movement is obtained by analyzing the distance between the edges. In the present embodiment, only one navigation sensor 30 is mounted on the bottom surface of the HMP 20. Previously there were two. However, for the sake of explanation, the HMP 20 having two navigation sensors 30 may be described. Note that a multi-axis acceleration sensor may be used as the navigation sensor 30, and the HMP 20 may detect the movement amount of the HMP 20 only by the acceleration sensor.

  The gyro sensor 31 is a sensor that detects an angular velocity when the HMP 20 rotates about an axis perpendicular to the print medium 12. Details will be described later.

  An OPU (Operation panel Unit) 26 has an LED for displaying the state of the HMP 20, a switch for the user to instruct the HMP 20 to form an image, and the like. However, the present invention is not limited to this, and may have a liquid crystal display and may further have a touch panel. Further, it may have a voice input function.

  The IJ recording head driving circuit 23 generates a driving waveform (voltage) for driving the IJ recording head 24 using the above driving waveform data. A drive waveform corresponding to the ink droplet size can be generated.

  The IJ recording head 24 is a head for ejecting ink. In the figure, four colors of CMYK ink can be ejected, but it may be a single color or ejecting five or more colors. A plurality of ink ejection nozzles 61 (ejection units) arranged in a line (may be two or more) for each color are arranged. Further, the ink ejection method may be a piezo method or a thermal method, or any other method. The IJ recording head 24 is a functional component that ejects and ejects liquid from the nozzle 61. The liquid to be ejected is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the IJ recording head 24. However, the viscosity is 30 [mPa · s] at normal temperature, normal pressure, or by heating and cooling. The following is preferable. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. , Edible materials such as natural pigments, solutions, suspensions, emulsions, and the like. These include, for example, inkjet inks, surface treatment liquids, components of electronic devices and light emitting devices, and formation of electronic circuit resist patterns. It can be used in applications such as liquids for use, three-dimensional modeling material liquids, and the like.

  The control unit 25 has a CPU 33 and controls the entire HMP 20. Based on the amount of movement detected by the navigation sensor 30 and the angular velocity detected by the gyro sensor 31, the control unit 25 determines the position of each nozzle of the IJ recording head 24 and the image to be formed according to the position, which will be described later. Judgment as to whether or not the discharge nozzle is possible. Details of the control unit 25 will be described below.

  FIG. 4 is an example of a diagram illustrating the configuration of the control unit 25. The control unit 25 has a SoC 50 and an ASIC / FPGA 40. The SoC 50 and the ASIC / FPGA 40 communicate via buses 46 and 47. This means that the ASIC / FPGA 40 may be designed by any mounting technology, and may be configured by other mounting technology other than the ASIC / FPGA 40. Further, the SoC 50 and the ASIC / FPGA 40 may be configured as a single chip or substrate without using separate chips. Or you may mount with three or more chips | tips or a board | substrate.

  The SoC 50 has functions such as a CPU 33, a position calculation circuit 34, a memory CTL (controller) 35, and a ROM CTL (controller) 36 connected via a bus 47. In addition, the component which SoC50 has is not restricted to these.

  The ASIC / FPGA 40 includes an image RAM 37, a DMAC 38, a rotator 39, an interrupt controller 41, a navigation sensor I / F 42, a print / sensor timing generation unit 43, an IJ recording head control unit 44, and a gyro connected via a bus 46. A sensor I / F 45 is provided. In addition, the component which ASIC / FPGA40 has is not restricted to these.

  The CPU 33 executes firmware (program) or the like developed from the ROM 28 to the DRAM 29, and controls operations of the position calculation circuit 34, the memory CTL 35, and the ROM CTL 36 in the SoC 50. Also, the operations of the Image RAM 37, DMAC 38, rotator 39, interrupt controller 41, navigation sensor I / F 42, print / sensor timing generation unit 43, IJ recording head control unit 44, gyro sensor I / F 45, etc. in the ASIC / FPGA 40 are performed. Control.

The position calculation circuit 34 calculates the position (coordinate information) of the HMP 20 based on the movement amount for each sampling period detected by the navigation sensor 30 and the angular velocity for each sampling period detected by the gyro sensor 31. Strictly speaking, the position of the HMP 20 is the position of the nozzle 61, but if the position of the navigation sensor 30 is known, the position of the nozzle 61 can be calculated. In the present embodiment, it refers to the position of the navigation sensor S ₀ as the position of the navigation sensor 30 unless otherwise specified. Further, the position calculation circuit 34 calculates a target discharge position. The position calculation circuit 34 may be realized by the CPU 33 in software.

  As will be described later, the position of the navigation sensor 30 is calculated on the basis of, for example, a predetermined origin (the initial position of the HMP 20 when image formation is started). The position calculation circuit 34 estimates the moving direction and acceleration based on the difference between the past position and the newest position, and predicts the position of the navigation sensor 30 at the next discharge timing, for example. In this way, it is possible to discharge ink while suppressing a delay with respect to scanning by the user.

  The memory CTL 35 is an interface with the DRAM 29, requests data from the DRAM 29, sends the acquired firmware to the CPU 33, and sends the acquired image data to the ASIC / FPGA 40.

  The ROM CTL 36 is an interface with the ROM 28, requests data from the ROM 28, and sends the acquired data to the CPU 33 and the ASIC / FPGA 40.

  The rotator 39 rotates the image data acquired by the DMAC 38 in accordance with the head that ejects ink, the nozzle position in the head, the head tilt due to attachment errors, and the like. The DMAC 38 outputs the rotated image data to the IJ recording head control unit 44.

  The image RAM 37 temporarily stores the image data acquired by the DMAC 38. That is, a certain amount of image data is buffered and read according to the position of the HMP 20.

  The IJ recording head control unit 44 performs dither processing on the image data (bitmap data) to convert the image data into a set of points representing the image with size and density. As a result, the image data becomes data of the ejection position and the dot size. The IJ recording head control unit 44 outputs a control signal corresponding to the dot size to the IJ recording head drive circuit 23. The IJ recording head drive circuit 23 generates a drive waveform (voltage) using the drive waveform data corresponding to the control signal as described above.

  The navigation sensor I / F 42 communicates with the navigation sensor 30, receives movement amounts ΔX ′ and ΔY ′ (which will be described later) as information from the navigation sensor 30, and stores the values in an internal register.

  The print / sensor timing generation unit 43 notifies the timing at which the navigation sensor I / F 42 and the gyro sensor I / F 45 read information, and notifies the IJ recording head control unit 44 of the drive timing. The period of timing for reading information is longer than the period of ink ejection timing. The IJ recording head control unit 44 determines whether or not the ejection nozzle is available, and determines that ink is ejected if there is a target ejection position where ink should be ejected, and that ejection is not performed if there is no target ejection position.

  The gyro sensor I / F 45 acquires the angular velocity detected by the gyro sensor 31 at the timing generated by the printing / sensor timing generation unit 43 and stores the value in the register.

  The interrupt controller 41 detects that the navigation sensor I / F 42 has completed communication with the navigation sensor 30 and outputs an interrupt signal for notifying the SoC 50 of the completion. The CPU 33 acquires ΔX ′ and ΔY ′ stored in the internal register by the navigation sensor I / F 42 by this interruption. In addition, it has a status notification function for errors and the like. Similarly for the gyro sensor I / F 45, the interrupt controller 41 outputs an interrupt signal for notifying the SoC 50 that the communication with the gyro sensor 31 is completed.

<Gyro sensor>
FIG. 5 is an example for explaining the principle by which the gyro sensor 31 detects the angular velocity. When rotation is applied to a moving object, Coriolis force is generated in a direction perpendicular to both the moving direction of the object and the rotation axis.

In order to move the object, the gyro sensor 31 generates a velocity v (vector) by vibrating a micro electro mechanical systems (MEMS) element. When rotation of an angular velocity ω (vector) is applied to a vibrating MEMS element having a mass m, a Coriolis force is applied to the MEMS element. The Coriolis force F can be expressed as follows.
F = -2mΩ × v
Note that “x” represents an outer product of vectors, and the direction of the Coriolis force F is a direction orthogonal to the moving direction of the object and the rotation axis as described above. The MEMS element has, for example, an electrode having a comb-tooth structure, and the gyro sensor 31 captures a displacement generated by the Coriolis force F as a change in capacitance. A signal of the Coriolis force F is amplified and filtered in the gyro sensor 31, and then calculated and output as an angular velocity. That is, since F, m, and v are known, the angular velocity ω can be extracted.

<About navigation sensors>
FIG. 6 is a diagram illustrating a configuration example of the hardware configuration of the navigation sensor. The navigation sensor 30 includes a host I / F 301, an image processor 302, an LED driver 303, two lenses 304 and 306, and an image array 305. The LED driver 303 is an integrated LED and control circuit, and emits LED light according to a command from the image processor 302. The image array 305 receives the reflected light of the LED light from the print medium 12 via the lens 304. The two lenses 304 and 306 are installed so as to be optically focused on the surface of the print medium 12.

  The image array 305 includes a photodiode having sensitivity to the wavelength of the LED light, and generates image data from the received LED light. The image processor 302 obtains the image data, and calculates the movement distance (ΔX ′, ΔY ′) of the navigation sensor from the image data. The image processor 302 outputs the calculated moving distance to the control unit 25 via the host I / F 301.

  A light emitting diode (LED) used as a light source is useful when a printing medium 12 having a rough surface, such as paper, is used. This is because, when the surface is rough, a shadow is generated, so that the movement distance in the X-axis direction and the Y-axis direction can be accurately calculated using the shadow as a characteristic part. On the other hand, a semiconductor laser (LD) that generates laser light can be used as a light source for the printing medium 12 having a smooth surface or a transparent surface. This is because a feature portion can be created by forming a striped pattern or the like on the print medium 12 with a semiconductor laser, and the movement distance can be accurately calculated based on the feature portion.

  Next, the operation of the navigation sensor 30 will be described with reference to FIG. FIG. 7 is a diagram for explaining a method of detecting the movement amount by the navigation sensor 30. The light emitted from the LED driver 303 is applied to the surface of the print medium 12 through the lens 306. The surface of the print medium 12 has minute irregularities of various shapes as shown in FIG. For this reason, various shapes of shadows are generated.

  The image processor 302 receives the reflected light through the lens 304 and the image array 305 at every predetermined sampling timing, and acquires the image data 310. The image processor 302 forms the image data 310 generated as shown in FIG. 7B in a matrix with a prescribed resolution unit. That is, the image data 310 is divided into a plurality of rectangular areas. Then, the image processor 302 compares the image data 310 obtained at the previous sampling timing with the image data 310 obtained at the current sampling timing to detect the number of rectangular regions to which the image data 310 has moved, It is calculated as the moving distance. Assume that the HMP 20 moves in the ΔX direction illustrated in FIG. When the image data 310 at t = 0 and t = 1 is compared, the shape at the right end matches the shape at the center. Therefore, since the shape has moved in the −X direction, it can be seen that the HMP 20 has moved by one square in the X direction. The same applies to times t = 1 and t = 2.

<IJ recording head drive circuit>
FIG. 8 is an example of a configuration diagram of the IJ recording head drive circuit 23. First, the IJ recording head 24 includes a plurality of nozzles 61, and each nozzle 61 is provided with an actuator. The actuator may be either a thermal type or a piezo type. In the thermal method, the ink in the nozzle is heated and expanded, and ink droplets are ejected from the nozzle 61 by this expansion. In the piezo method, ink droplets are ejected by pushing a nozzle wall with a piezoelectric element and pushing out ink inside.

  The IJ recording head drive circuit 23 includes an analog switch 231, a level shifter 232, a gradation decoder 233, a latch 234, and a shift register 235. The IJ recording head control unit 44 sends the image data SD, which is serial data corresponding to the number of nozzles 61 (the number of actuators) of the IJ recording head 24, to the IJ recording head drive circuit 23 by the image data transfer clock SCK. Transfer to the shift register 235.

  When the transfer is completed, the IJ recording head control unit 44 stores each image data SD in the latch 234 provided for each nozzle by the image data latch signal SLn.

  The IJ recording head control unit 44 latches the image data SD, and then outputs a head drive waveform Vcom for ejecting ink droplets of each gradation value from each nozzle to the analog switch 231. At this time, the IJ recording head control unit 44 gives the head drive mask pattern MN as a gradation control signal to the gradation decoder 233, and selects the head drive mask pattern MN in accordance with the timing of the drive waveform. Transition.

  The gradation decoder 233 performs a logical operation on the gradation control signal and the latched image data, and the level shifter 232 boosts the logical level voltage signal obtained by the logical operation to a voltage level at which the analog switch 231 can be driven.

  The analog switch 231 receives the boosted voltage signal and turns it ON / OFF, so that the drive waveform VoutN supplied to the actuator of the IJ recording head has a different waveform for each nozzle. The IJ recording head 24 ejects ink droplets based on this drive waveform to form an image on the print medium 12.

  Note that the configuration in FIG. 8 and the description thereof are configurations generally employed in ink jet printers. As long as ink droplets can be ejected, the configuration is not limited to the configuration shown in FIG.

<Regarding the nozzle position in the IJ recording head>
Next, the nozzle position and the like in the IJ recording head 24 will be described with reference to FIG. FIG. 9A is an example of a plan view of the HMP 20. FIG. 9B is an example for explaining only the IJ recording head 24. The surface shown is the surface facing the print medium 12.

HMP20 of this embodiment has one navigation sensor _{S 0.} Figure 9 S ₁ of (a), for convenience of explanation, the installation position of case navigation sensors there are two. When there are two navigation sensors 30, the length between the two navigation sensors S ₀ and S ₁ is the distance L. The longer the distance L, the better. This is because the minimum detectable rotation angle θ decreases as the distance L increases, and the position error of the HMP 20 decreases.

The distances from the navigation sensor 30 to the IJ recording head 24 are distances a and b, respectively. The distance a and the distance b may be equal to each other or may be zero (in contact with the IJ recording head 24). When there is only one navigation sensor 30, the navigation sensor S ₀ is arranged at an arbitrary location around the IJ recording head 24. Accordingly, the position of the navigation sensors S ₀ illustrated is an example. However, the distance of the IJ recording head 24 and the navigation sensor _{S 0} is likely to reduce the bottom size of the HMP20 by short.

  As shown in FIG. 9B, the distance from the end of the IJ recording head 24 to the first nozzle 61 is a distance d, and the distance between adjacent nozzles is a distance e. The values a to e are stored in advance in the ROM 28 or the like.

If the position calculation circuit 34 or the like calculates the position of the navigation sensor S ₀ , the position calculation circuit 34 can calculate the position of the nozzle 61 using the distance a (distance b), the distance d, and the distance e.

<About the position of the HMP 20 in the print medium 12>
FIG. 10 is an example of a diagram illustrating a coordinate system of the HMP 20 and a method for calculating the position. In this embodiment, the horizontal direction to the print medium 12 is set as the X axis, and the vertical direction is set as the Y axis. Origin is the position of the navigation sensors S ₀ when the image forming is started. These coordinates will be referred to as print medium coordinates. In contrast, navigation sensors _{S 0} coordinate axes (X'axis, Y'-axis) in FIG. 10 outputs the movement amount. That is, the movement amount is output with the arrangement direction of the nozzles 61 as the Y ′ axis and the direction orthogonal to the Y ′ axis as the X ′ axis.

As shown in FIG. 9A, the case where the HMP 20 is rotated clockwise θ with respect to the print medium 12 will be described as an example. It is difficult for the user to scan the HMP 20 without tilting the print medium coordinates at all, and it is considered that a non-zero θ is generated. If there is no rotation, X = X ′ and Y = Y ′. However, when the HMP 20 rotates with respect to the print medium 12 by the rotation angle θ, the output of the navigation sensor S ₀ and the actual position of the HMP 20 on the print medium 12 do not match. The rotation angle θ is positive in the clockwise direction, X and X ′ are positive in the right direction, and Y and Y ′ are positive in the upward direction.

FIG. 10A is an example for explaining the X coordinate of the HMP 20. Figure 10 (a) the amount of movement navigation sensors S ₀ when HMP20 the rotation angle θ is moved while the same rotation angle θ only in the X direction is detected ΔX', ΔY' and X, which indicates the correspondence Y . When there are two navigation sensors 30, the relative positions are fixed, so the outputs (movement amounts) of the two navigation sensors 30 are the same. X coordinate of the navigation sensors _{S 0} is X1 + X2, X1 + X2 is DerutaX', determined from ΔY' and the rotation angle theta.

FIG. 10B shows the correspondence between the movement amounts ΔX ′, ΔY ′ and X, Y detected by the navigation sensor S ₀ when the HMP 20 with the rotation angle θ moves in the Y direction with the same rotation angle θ. . Y coordinates of the navigation sensors _{S 0} is the Y1 + Y2, Y1 + Y2 is -DerutaX', determined from ΔY' and the rotation angle theta.

Therefore, when the HMP 20 moves in the X direction and the Y direction with the rotation angle θ, ΔX ′ and ΔY ′ output from the navigation sensor S ₀ can be converted into X and Y of the print medium coordinates as follows.
X = ΔX′cos θ + ΔY′sin θ (1)
Y = −ΔX′sin θ + ΔY′cos θ (2)
<< Detection of rotation angle θ >>
In the present embodiment, the position calculation circuit 34 obtains the rotation angle θ from the output of the gyro sensor 31. However, in order to show that the longer the distance L, the position can be obtained with high accuracy, how to obtain the rotation angle θ when there are two navigation sensors 30 will be described.

FIG. 11 is an example for explaining how to obtain the rotation angle dθ of the HMP 20 generated during image formation. The rotation angle dθ is calculated using the movement amount ΔX ′ detected by the two navigation sensors S ₀ and S ₁ . Movement amount ΔX'0 the upper navigation sensors S ₀ of the printing medium 12 is detected, the movement amount of navigation sensor S ₁ is detected and DerutaX'1. In FIG. 11, the rotation angle already obtained is θ.

When the HMP 20 rotates dθ while moving in parallel, the movement amounts ΔX ′ 0 and ΔX ′ 1 do not match. However, since both outputs are movement amounts in the direction perpendicular to the straight line connecting the two navigation sensors S ₀ and S ₁ , the difference between the movement amounts ΔX ′ 0 and ΔX ′ 1 is obtained as “ΔX ′ 0 −ΔX ′ 1”. be able to. This difference is a value generated by the HMP 20 rotating dθ. Further, since “ΔX′0−ΔX′1”, L, and dθ have the relationship shown in FIG. 11, dθ can be expressed as follows.
dθ = arcsin {(ΔX′0−ΔX′1) / L} (3)
The position calculation circuit 34 can calculate the rotation angle θ by integrating the dθ. As shown in equations (1) and (2), since the rotation angle θ is used for position calculation, the rotation angle θ affects the position accuracy. As can be seen from the equation (3), it is preferable to increase the distance L in order to detect a smaller dθ. Therefore, although the distance L affects the position accuracy, if the distance L is increased, the bottom area of the HMP 20 is increased, and the image formable range 501 is decreased.

Next, a method for calculating the rotation angle θ using the output of the gyro sensor 31 will be described. The output of the gyro sensor 31 is an angular velocity ω.
ω = dθ / dt
Therefore, when dt is a sampling period, the rotation angle dθ can be expressed as follows.
dθ = ω × dt
Therefore, the current rotation angle θ (time t = 0 to N) is as follows.

Thus, the gyro sensor 31 can also determine the rotation angle θ. As shown in equations (1) and (2), the position can be calculated using the rotation angle θ. If the position of the navigation sensor S ₀ can be calculated, the position calculation circuit 34 can calculate the coordinates of each nozzle 61 based on the values a to e shown in FIG. Since X in equation (1) and Y in equation (2) are the amounts of change in the sampling period, the current position can be obtained by accumulating X and Y.

<Target discharge position>
Next, the target discharge position will be described with reference to FIG. FIG. 12 is an example for explaining the relationship between the target discharge position and the position of the nozzle 61. The target ejection positions G1 to G9 are target positions (pixel formation destinations) at which the HMP 20 lands ink from the nozzles 61. The target discharge positions G1 to G9 can be obtained from the initial position of the HMP 20 and the resolution (Xdpi, Ydpi) of the HMP 20 in the X axis / Y axis direction.

  For example, when the resolution is 300 dpi, the target ejection position is set every about 0.084 [mm] in the longitudinal direction of the IJ recording head 24 and the direction perpendicular thereto. If there are pixels to be ejected at the target ejection positions G1 to G9, the HMP 20 ejects ink.

  However, in practice, since it is difficult to capture the timing at which the nozzle 61 and the target discharge position completely coincide with each other, the HMP 20 has an allowable error 62 between the target discharge position and the current position of the nozzle 61. When the current position of the nozzle 61 is within the range of the allowable error 62 from the target discharge position, ink is discharged from the nozzle 61 (providing such an allowable range is referred to as “discharge nozzle availability determination”).

  As indicated by an arrow 63, the HMP 20 monitors the moving direction and acceleration of the nozzle 61 and predicts the position of the nozzle 61 at the next discharge timing. Therefore, it is possible to prepare for ink ejection by comparing the predicted position with the allowable error 62.

<Operation procedure>
FIG. 13 is an example of a flowchart for explaining the operation procedure of the image data output unit 11 and the HMP 20. First, the user presses the power button of the image data output device 11 (U101). The image data output unit 11 accepts it, and is activated when power is supplied from a battery or the like.

  The user selects an image to be output by the image data output unit 11 (U102). The image data output unit 11 accepts image selection. Document data of software such as a word processor application may be selected as an image, or image data such as JPEG may be selected. If necessary, the printer driver may change data other than image data into an image.

  The user performs an operation of printing the selected image with the HMP 20 (U103). The HMP 20 accepts a print job execution request. Image data is transmitted to the HMP 20 in response to a print job request.

  The user holds the HMP 20 and determines an initial position on the print medium 12 (for example, a notebook) (U104).

  Then, the user presses the print start button of the HMP 20 (U105). The HMP 20 accepts pressing of the print start button.

  The user freely scans the HMP 20 to slide on the print medium 12 (U106).

  Subsequently, the operation of the HMP 20 will be described. The following operation is performed by the CPU 33 executing the firmware.

  The HMP 20 is also activated when the power is turned on. The CPU 33 of the HMP 20 initializes the hardware elements shown in FIGS. 3 and 4 built in the HMP 20 (S101). For example, the registers of the navigation sensor I / F 42 and the gyro sensor I / F 45 are initialized, or timing values are set in the print / sensor timing generation unit 43. Communication between the HMP 20 and the image data output unit 11 is established.

  The CPU 33 of the HMP 20 determines whether or not the initialization is completed, and if not completed, repeats this determination (S102).

  When the initialization is completed (Yes in S102), the CPU 33 of the HMP 20 notifies the user that printing is possible by, for example, LED lighting of the OPU 26 (S103). As a result, the user grasps the printable state and requests execution of the print job as described above.

  In response to a print job execution request, the communication I / F 27 of the HMP 20 accepts input of image data from the image data output unit 11, and notifies the user that the image has been input, for example, by blinking the LED of the OPU 26 (S104). ).

When the user determines the initial position of the HMP 20 on the print medium 12 and presses the print start button, the OPU 26 of the HMP 20 accepts this operation, and the CPU 33 causes the navigation sensor I / F 42 to read the position (movement amount) (S105). Thus, the navigation sensor I / F 42 communicates with the navigation sensors _{S 0,} is stored such as to get the amount of movement navigation sensor _{S 0} is detected register (S1001). The CPU 33 reads the movement amount from the navigation sensor I / F 42.

  Even if the movement amount acquired immediately after the user presses the print start button is zero but not zero, the CPU 33 stores the initial position of the coordinates (0, 0) in the DRAM 29 or the register of the CPU 33, for example (S106). .

When the initial position is acquired, the print / sensor timing generation unit 43 starts generating timing (S107). The print / sensor timing generation unit 43 instructs the navigation sensor I / F 42 to determine the timing and the gyro sensor I / F 45 to specify the timing when the acquisition timing of the movement amount of the navigation sensor S ₀ set in the initialization is reached. This is carried out periodically and becomes the above sampling period.

  The CPU 33 of the HMP 20 determines whether it is time to acquire the movement amount and angular velocity information (S108). This determination is performed by a notification from the interrupt controller 41, but may be determined by the CPU 33 counting the same timing as that of the print / sensor timing generation unit 43.

When it is time to acquire the movement amount and angular velocity information, the CPU 33 of the HMP 20 acquires the movement amount from the navigation sensor I / F 42 and acquires angular velocity information from the gyro sensor I / F 45 (S109). As described above, the gyro sensor I / F 45 acquires angular velocity information from the gyro sensor 31 at the timing generated by the print / sensor timing generation unit 43, and the navigation sensor I / F 42 is generated by the print / sensor timing generation unit 43. It has acquired movement amount at the timing of the navigation sensors S _0.

Then, the position calculation circuit 34 calculates the current position of the navigation sensors S ₀ using the amount of movement and the angular velocity information (S110). Specifically, the position calculation circuit 34 adds the position (X, Y) calculated in the previous cycle, the movement amount (ΔX ′, ΔY ′) acquired this time and the movement distance calculated from the angular velocity information, to the calculated position of the navigation sensor S _0. If only the initial position and there is no previously calculated position, the current position of the navigation sensor S ₀ is obtained by adding the movement distance (ΔX ′, ΔY ′) acquired this time and the movement distance calculated from the angular velocity information to the initial position. calculate.

Then, the position calculation circuit 34 calculates the current position of the nozzles 61 with the current position of the navigation sensor S ₀ (S111).

  As described above, since the angular velocity information and the movement amount are acquired simultaneously or substantially simultaneously by the printing / sensor timing generation unit 43, the position of the nozzle 61 is calculated with the movement amount acquired at the timing when the rotation angle and the rotation angle are detected. it can. Therefore, even if the position of the nozzle 61 is calculated using information from sensors of different types, the accuracy of the position of the nozzle 61 is unlikely to decrease.

  Next, the CPU 33 controls the DMAC 38 to transmit the image data of the peripheral image of each nozzle 61 from the DRAM 29 to the Image RAM 37 based on the calculated position of each nozzle 61 (S112). The rotator 39 rotates the image in accordance with the head position designated by the user (such as how to hold the HMP 20) and the tilt of the IJ recording head 24.

  Next, the IJ recording head control unit 44 compares the position coordinates of each image element constituting the peripheral image with the position coordinates of each nozzle 61 (S113). The position calculation circuit 34 calculates the acceleration of the nozzle 61 using the past position and the current position of the nozzle 61. Accordingly, the position calculation circuit 34 determines the position of the nozzle 61 for each ink discharge period of the IJ recording head 24 that is shorter than the period in which the navigation sensor I / F 42 acquires the movement amount and the gyro sensor I / F 45 acquires angular velocity information. Calculated.

  The IJ recording head control unit 44 determines whether or not the position coordinates of the image element are included within a predetermined range from the position of the nozzle 61 calculated by the position calculation circuit 34 (S114).

  If the discharge condition is not satisfied, the process returns to step S108. When the ejection condition is satisfied, the IJ recording head control unit 44 outputs image element data for each nozzle 61 to the IJ recording head drive circuit 23 (S115). As a result, ink is ejected onto the print medium 12.

  Next, the CPU 33 determines whether all image data has been output (S116). When not outputting, the process from step S108 to S115 is repeated.

  When all the image data has been output, the CPU 33 turns on the LED of the OPU 26, for example, and notifies the user that printing has ended (S117).

  If the user determines that the image data is not required to be output, the user may press the print completion button, and the OPU 26 may accept it and end printing. The user can turn off the power after the printing is completed, or the power may be automatically turned off when the printing is finished.

<Image formable range with one navigation sensor>
The image formable range 501 when there is one navigation sensor will be described with reference to FIGS. FIG. 14 is an example for explaining an image formable range 501 in the case where there are two navigation sensors 30 shown for comparison.

In FIG. 14A, two navigation sensors 30 are arranged in parallel with the nozzle. FIG. 14A shows the HMP 20 as viewed from above. FIG. 14B shows a polygon 502 formed by parts (navigation sensor, nozzle) that must be on the print medium 12 in the arrangement of FIG. Polygon 502 is an example of the size of the bottom surface. The distance from the nozzle 61 forming the polygon 502 to the right navigation sensors S ₀ and S ₁ is A [mm], and the distance from the lower end of the nozzle 61 to the lower navigation sensor S ₁ is B [mm].

FIG. 14C shows an image formable range 501 in the arrangement shown in FIG. Since the nozzle 61 is at the left end and the upper end of the polygon 502, an image can be formed from the upper end of the left end of the print medium 12. On the other hand, since the distance from the nozzle 61 to the right navigation sensors S ₀ and S ₁ is A [mm], the nozzle 61 cannot move to the right of A [mm] from the right end of the print medium 12 (image formation cannot be performed). ). Therefore, the right end of the image formable range 501 is a place having a length A [mm] from the right end of the print medium 12. Similarly distance from the nozzle 61 to the navigation sensor S ₁ of the lower side since B [mm], the nozzle 61 can not move downward than B [mm] from the bottom short of the printing medium 12 (not be the image formation). For this reason, the lower end of the image formable range 501 is a place having a length B [mm] from the lower end of the print medium 12.

In FIG. 14D, two navigation sensors S ₀ and S ₁ are arranged in series above and below the nozzle 61. FIG. 14 (e) shows a polygon 502 formed by parts (navigation sensor, nozzle) that must be on the print medium 12 in the arrangement of FIG. 14 (d). A length from the navigation sensors S ₀ to S ₁ forming the polygon 502 is A [mm].

  FIG. 14F shows an image formable range 501 in the arrangement shown in FIG. Since the vertical length of the print medium 12 is shorter than the length A [mm], the HMP 20 cannot form an image on the print medium 12. Even if the HMP 20 is rotated 90 degrees and the HMP 20 is arranged in parallel to the horizontal direction of the print medium 12, the horizontal length of the print medium 12 is shorter than the length A [mm], so Can not form. For this reason, the image formable range 501 does not exist in FIG.

  As described above, when any one of the two navigation sensors 30 protrudes from the print medium 12, the HMP 20 cannot detect the position (the position becomes inaccurate). Therefore, the size of the bottom surface of the HMP 20 is large. There has been a disadvantage in that the image formable range 501 on the medium 12 is limited. Of course, even if the two navigation sensors 30 are on the print medium 12, the HMP 20 cannot form an image if the IJ recording head 24 protrudes from the print medium 12. Therefore, the two navigation sensors 30 and the IJ recording head 24 must be inside the print medium 12, and the image formable range 501 is limited. For this reason, in the conventional HMP 20, it may be difficult for a user to form an image using a wide space.

FIG. 15 is an example for explaining an image formable range 501 in the case where there is one navigation sensor 30. In FIG. 15A, one navigation sensor S ₀ is arranged in series with the nozzle 61. That is, navigation sensors S ₀ are arranged adjacent in a state of close as possible beneath the nozzle 61. FIG. 15A shows the HMP 20 as viewed from above. FIG. 15B shows a polygon 502 formed by parts (navigation sensor, nozzle) that must be on the print medium 12 in the arrangement of FIG. The distance to the lower end and navigation sensors S ₀ of nozzles 61 that form a polygon 502 is A mm.

FIG. 15C shows an image formable range 501 in the arrangement shown in FIG. Since the polygon 502 is substantially linear, an image can be formed from the upper end of the left end of the print medium 12 to the upper end of the right end of the print medium 12. However, since A [mm] is spacing up navigation sensors S ₀ of the lower from the nozzle 61, the nozzle 61 can not move downward than A (mm) from the bottom short of the printing medium 12 (not be the image formation). For this reason, the lower end of the image formable range 501 is a place having a length A [mm] from the lower end of the print medium 12.

As can be seen from a comparison between FIGS. 14C and 14F, and FIG. 15C, it can be seen that the image forming possible range 501 is greatly expanded by using one navigation sensor 30. FIG. In particular, since the upper half or more of the print medium 12 becomes the image formable range 501, when the HMP 20 is inverted 180 degrees, the lower half of the print medium 12 becomes the image formable range 501. Accordingly, the entire print medium 12 can be made the image formable range 501. Note that navigation sensors _{S 0} in FIG. 15 (a) may be disposed above the IJ recording head 24. In this case, the image formable range 501 is a range in which A [mm] remains from the lower end to the upper end of the print medium 12 (the image formable range 501 in FIG. 15C is inverted upside down).

One navigation sensor S ₀ in a direction perpendicular to the array direction of FIG. 15 (d) the nozzle 61 is arranged. That is, navigation sensors S ₀ are arranged adjacent in a state of close as possible to the right of the nozzle 61. FIG. 15E shows a polygon 502 formed by parts (navigation sensor, nozzle) that must be on the print medium 12 in the arrangement of FIG. 15D. The distance to the nozzle and navigation sensors S ₀ to form a polygon 502 is A mm.

FIG. 15F shows an image formable range 501 in the arrangement shown in FIG. Nozzles can be image forming because there is no navigation sensors S ₀ below the upper end and located at the left end nozzle 61 of the polygon 502 from the left end of the top edge of the print medium 12 to the lower end. However, the distance to the right of the navigation sensors S ₀ is because A [mm] from the nozzle 61, the nozzle 61 can not move in the right direction than A (mm) from the right end of the printing medium 12 (not be the image formation). Therefore, the right end of the image formable range 501 is a place having a length A [mm] from the right end of the print medium 12.

As can be seen from a comparison between FIGS. 14C and 14F, and FIG. 15F, it can be seen that the number of the image forming possible range 501 is greatly expanded by using one navigation sensor 30. Particularly, since the left half or more of the print medium 12 is the image formable range 501, the right half of the print medium 12 becomes the image formable range 501 when the HMP 20 is inverted 180 degrees. Accordingly, the entire print medium 12 can be made the image formable range 501. Incidentally, in FIG. 15 (d), the navigation sensors _{S 0} may be disposed on the left side of the IJ recording head 24. In this case, the image formable range 501 is a range from the right end to the left end of the print medium 12 where A [mm] is left (the image formable range 501 in FIG. 15F is horizontally reversed).

Further, as shown in FIG. 16, a navigation sensor S ₀ may be arranged in the IJ recording head 24. Figure 16 is an example of a diagram for explaining an example of arrangement of navigation sensors S _0. Navigation sensors S ₀ is placed into a hole provided in the bracket (holding member) which surrounds the example nozzle 61. Alternatively, if the navigation sensor S ₀ may not be in the vicinity of the bottom surface, navigation sensors S ₀ to the inside of the housing may be installed from the bottom surface. In this case, it can be shortened intervals navigation sensors S ₀ and the nozzle 61 so the navigation sensors S ₀ and the nozzle 61 on the same plane may not be disposed.

<Gyro sensor placement example>
It is known that the gyro sensor 31 is preferably arranged closer to the center of rotation. However, the center of rotation of the HMP 20 is often near the elbow of the user than when it is the center or center of gravity of the HMP 20. This is because the user scans the HMP 20 around the elbow. Therefore, the gyro sensor 31 is preferably arranged as shown in FIG.

  FIG. 17A is an example of a diagram illustrating an arrangement example of the gyro sensor 31. The gyro sensor 31 is disposed on the front side of the housing of the HMP 20 and substantially at the center in the width direction. This is because it is closest to the user's elbow. With such an arrangement, it is expected that the accuracy of the angular velocity to be detected is improved because the gyro sensor 31 is arranged at a location near the rotation center. Note that the user may scan the HMP 20 while being rotated 90 degrees or 180 degrees. Considering this point, it is preferable that at least one gyro sensor 31 is installed at the end of the HMP 20 in a plan view from above the HMP 20.

  On the other hand, when the HMP 20 is a rigid body, the necessary accuracy cannot be obtained unless the HMP 20 is always disposed on the front side of the housing, and the practically sufficient accuracy can be obtained wherever the HMP 20 is disposed. However, the vicinity of the portion of the HMP 20 that can be touched by the user may be deformed by applying a weight when the user scans the HMP 20. When such a deformation is transmitted to the gyro sensor 31, there is a possibility that noise may enter the angular velocity.

  Therefore, it is preferable that the gyro sensor 31 is disposed in a state that the user cannot touch inside the housing of the HMP 20 and is not easily deformed. Specifically, it is arranged on the printed circuit board 70 near the bottom surface of the HMP 20. The printed circuit board 70 is a plate-shaped component made of resin or the like, on which electronic components, integrated circuits (ICs), and metal wirings connecting them are mounted with high density. The printed circuit board is sometimes called a PWB or an electronic board. By being arranged in this way, even if the HMP 20 is deformed by a general human force, it is difficult to be transmitted to the gyro sensor 31, so that noise can be prevented from entering the angular velocity.

  Further, it is known that the angular velocity of the gyro sensor 31 is affected by a temperature change, and it is preferable that the gyro sensor 31 is arranged in a place where the temperature change in the housing is small. A circuit through which a large amount of current flows, such as an SoC, an LSI such as ASIC / FPGA, or a power supply, is a heating element that generates heat during operation. Therefore, the temperature change is large near these circuits. For this reason, it is preferable that the gyro sensor 31 is disposed as far as possible from the SoC 50 and the ASIC / FPGA 40 as shown in FIG. In FIG. 17B, the gyro sensor 31 is arranged on a printed circuit board 70 different from at least SoC and ASIC / FPGA.

  Since a human hand also serves as a heat source, it is preferable that the gyro sensor 31 is disposed near the bottom surface from this point.

  When the temperature characteristic is linear or the temperature characteristic can be investigated in advance, the temperature may be measured by a temperature sensor, and the angular velocity may be corrected according to the temperature characteristic.

It is also effective that the navigation sensor S ₀ and the gyro sensor 31 are mounted on the same printed circuit board 70. In FIG. 17C, the gyro sensor 31 and the navigation sensor S ₀ on the near side of the HMP 20 are arranged on one printed circuit board 70. Not particularly contribute to the reduction of the bottom size of the HMP20 be closer the positions of the gyro sensor 31 and the navigation sensor S _0. However, when the gyro sensor 31 has three axes, a change in posture other than the rotation angle with respect to an axis perpendicular to the print medium 12 can be detected, and thus there is an advantage as follows.

FIG. 18 is an example of a diagram illustrating the attitude of the HMP 20 detected by the gyro sensor 31. When the gyro sensor 31 is triaxial, angular velocities in the yaw direction, roll direction, and pitch direction can be detected. Of these, the angular velocity in the yaw direction is used to calculate the position of the navigation sensor. If angular velocities in the roll direction and the pitch direction are detected during image formation, the navigation sensor S ₀ may have moved away from the print medium 12. When the navigation sensor S ₀ and the gyro sensor 31 are arranged on the same printed circuit board 70, an angular velocity equivalent to the angular velocity in the roll direction and the pitch direction detected by the gyro sensor 31 also acts on the navigation sensor S ₀ . Since it is considered, it is easy to detect that the angular velocity in the roll direction or the pitch direction is generated so that the navigation sensor S ₀ is separated from the print medium 12.

Therefore, when the navigation sensor S ₀ and the gyro sensor 31 are arranged on the same printed circuit board 70, it is easy to detect whether the navigation sensor S ₀ is separated from the print medium 12 by using the three-axis gyro sensor 31. .

<Process when assembling the gyro sensor 31>
Further, when the gyro sensor 31 can detect the triaxial angular velocity, the HMP 20 or the like can detect the assembly accuracy when the gyro sensor 31 is assembled to the HMP 20. It is preferable that the gyro sensor 31 is assembled to the HMP 20 as horizontally as possible. By doing so, all changes in the attitude of the HMP 20 in the yaw direction can be detected by the angular velocity. However, in the actual assembly, there may be a slight deviation from the horizontal, and in this case, the angular velocity in the roll direction or the pitching direction may be detected even if the user rotates the HMP 20 only horizontally.

  Therefore, for example, the user operates the HMP 20 in a test mode or the like and scans the HMP 20 horizontally. The HMP 20 detects the angular velocity in the roll direction or the pitching direction, and determines how much the gyro sensor 31 is inclined with respect to the HMP 20. Knowing how much is tilted, the angular velocity in the yaw direction can be corrected.

  In addition, when the gyro sensor 31 detects an angular velocity of only one axis (yaw direction), a jig that can be moved in a range of 0 degrees → 90 degrees → 0 degrees is prepared. The HMP 20 detects the angle when the user is moving in the range of 0 ° → 90 ° → 0 ° with the jig. When the detected angle does not become 90 degrees, a correction coefficient that is 90 degrees is calculated and stored in the apparatus. Therefore, the angular velocity can be corrected during actual image formation.

  When the user scans the HMP 20 on the print medium 12, the bottom surface may slightly float from the print medium 12. Since the navigation sensor 30 also floats, the position detected by the navigation sensor 30 is not accurate. The position error due to the float can be ignored, but the resolution of the movement amount changes greatly.

  The resolution of the optical navigation sensor 30 is represented by CPI (Count Per Inch). This means the number counted while the navigation sensor 30 is moved by 1 inch. The larger the number, the higher the resolution.

  As shown in FIG. 19, the navigation sensor 30 changes the resolution of the movement amount depending on the distance between the paper surface and the navigation sensor 30. FIG. 19 is an example of a diagram illustrating changes in the distance between the sensor paper and the resolution of the movement amount. It can be seen that the resolution decreases as the distance between the sensor papers increases. This is because the navigation sensor 30 optically detects the edge of the print medium 12, and therefore the closer the sensor paper distance is, the more advantageous for edge detection (easy to detect minute edges).

  Since the navigation sensor 30 has such properties, the manufacturer of the HMP 20 detects the movement amounts of X and Y with a predetermined resolution (CPI) according to the assembly position of the navigation sensor 30 in the HMP 20.

  For this reason, when the HMP 20 floats from the print medium 12, the movement amount also shifts (only a movement amount smaller than the actual movement amount can be detected), and therefore some correction is preferably performed. In the present embodiment, the HMP 20 that suppresses the reduction in the resolution of the movement amount due to the floating of the HMP 20 from the print medium 12 will be described.

  FIG. 20A is a diagram showing the assembly position of the navigation sensor 30 from the top surface of the HMP 20, and FIG. 20B is a diagram for explaining the three-axis rotation of the navigation sensor 30.

  As illustrated in FIG. 20B, the print medium 12 is installed on the XY plane, and the direction perpendicular to the print medium 12 is the Z axis. As described in the first embodiment, the position of the nozzle 61 is calculated from the rotation angle about the Z axis. On the other hand, how much the navigation sensor 30 floats from the print medium 12 is affected by at least one of the rotation angle about the X axis and the rotation angle about the Y axis. Note that it is not necessary to consider that the entire navigation sensor 30 translates in the Z-axis direction. This is because, in general, the user does not use such a method, and an error occurs when the entire navigation sensor 30 floats greatly.

  If the rotation angle about the X axis at the start of printing and the rotation angle about the Y axis are zero, the gyro sensor 31 is rotated on the X axis (YZ plane) and on the Y axis (ZZ plane). By detecting this, the position calculation circuit 34 can detect floating during printing scanning.

  Next, a method for calculating the floating amount will be described with reference to FIG. FIG. 21 is an example of a diagram illustrating the floating amount of the navigation sensor 30 from the print medium 12. FIG. 21A is a side view when the navigation sensor 30 is viewed from the Y-axis direction of FIG. FIG. 21B shows the amount of floating when the navigation sensor 30 rotates (floats) about the left end, and FIG. 21C shows the case where the navigation sensor 30 rotates (floats) about the right end. Indicates the amount of floating.

  The distance from the left end of the housing of the HMP 20 of the navigation sensor 30 is L1, and the distance from the right end is L2. Since the rotation direction about the Y axis is reversed between when the left end is rotated and the right end is rotated, the position calculation circuit 34 determines the rotation direction (left end axis rotation and right end depending on whether the rotation angle is positive or negative). Shaft rotation). In the case of left end axis rotation, the floating amount is calculated as shown in FIG. 21B, and in the case of right end axis rotation, the floating amount is calculated as shown in FIG.

The rotation angle detected by the gyro sensor 31 is α. Α after the rotation direction is determined may be an absolute value. From FIG. 21 (b), the floating amount in the case of the left end shaft rotation is as follows.
L1sinα
Similarly, from FIG. 21 (c), the floating amount in the case of the left end shaft rotation is as follows.
L2sinα
Although the floating amount in FIGS. 21A and 21B is generated by the rotation about the Y axis, the HMP 20 also has a rotation about the X axis. For this reason, the position calculation circuit 34 also calculates the floating amount generated by the rotation about the X axis. From the above, the final floating amount is calculated as the sum (sum) of the floating amount by the X-axis center rotation and the floating amount by the Y-axis center rotation as follows.

The floating amount of the navigation sensor 30
= Floating amount (X axis rotation) + Floating amount (Y axis rotation)
In addition, when the navigation sensor 30 floats, the navigation sensor 30 moves not only in the height direction of the navigation sensor 30 but also in the lateral direction. The movement amounts are “L1-L1cosα” and “L2-L2cosα”. However, in actual scanning of the HMP 20, the floating amount is small and can be ignored.

  However, the difference in the resolution of the movement amount due to the change in the distance between the print medium 12 and the navigation sensor 30 caused by floating cannot be ignored. When the navigation sensor 30 is slightly lifted during scanning, the resolution of the movement amount output from the navigation sensor 30 changes greatly (becomes smaller). Therefore, the amount of movement detected than the amount of movement of the navigation sensor 30 actually. Becomes smaller.

  Therefore, the position calculation circuit 34 uses the proportional relationship between the sensor paper distance and the movement amount resolution shown in FIG. 19 to perform resolution conversion for converting the floating amount into a change in resolution, thereby correcting the movement amount. This will be described using a specific example.

For example, it is assumed that the relationship between the sensor paper distance of the navigation sensor 30 and the resolution of the movement amount is as follows.
When the distance between the print medium and the sensor is 2 mm, the equivalent of 4000 cpi When the distance between the print medium and the sensor is 2.1 mm, the equivalent of 3500 cpi In other words, when the floating amount changes from 2 mm to 2.1 mm, the resolution of the moving amount decreases by 500 cpi. This is because when the distance between the print medium and the sensor is 2 mm, the amount of movement output by the navigation sensor 30 when the navigation sensor 30 moves 1 mm is 157 counts, but when the distance between the print medium and the sensor changes to 2.1 mm, the navigation sensor 30 This means that the amount of movement output from the navigation sensor 30 when the 30 moves 1 mm decreases to 137 counts. Therefore, the movement amount of the navigation sensor 30 is calculated to be smaller than the actual movement amount, and the position of the navigation sensor 30 is displaced.

  However, as shown in FIG. 19, since the position calculation circuit 34 can estimate the resolution of the movement amount from the floating amount by holding the proportional relationship between the sensor paper distance and the resolution of the movement amount, the position calculation circuit 34 can estimate the position correction. It becomes possible.

  For example, the relationship between the sensor paper distance and the resolution of the movement amount as shown in FIG. y is the resolution of the moving amount, x is the distance between the sensor papers, and a and b are coefficients. Since x is obtained from the floating amount, the resolution of the moving amount can be obtained. The value obtained by dividing the resolution of the moving amount when the floating amount is zero by the resolution of the moving amount is multiplied by the moving amount (count number) detected when the navigation sensor 30 is floating. Thereby, even if the navigation sensor 30 floats, it can correct | amend to the movement amount in case the floating amount is zero.

  Since the proportional relationship between the distance between sensor papers and the resolution of the moving amount may change depending on the paper type, it is preferable to maintain the proportional relationship between the distance between the sensor papers and the resolution of the moving amount according to the paper type.

  FIG. 22 is an example of a flowchart for explaining the operation procedure of the image data output unit 11 and the HMP 20. In the description of FIG. 22, differences from FIG. 13 are mainly described.

  First, in step S106, the CPU 33 stores the initial angle (X, Y axes) of the gyro sensor 31 together with the initial position of the coordinates (0, 0), for example, in the register of the DRAM 29 or the CPU 33 (S106). That is, the CPU 33 reads the angular velocity information of the gyro sensor 31.

Then, the position calculating circuit 34 in step S110, when calculating the current position of the navigation sensors S ₀ using the amount of movement and the angular velocity information, the rotation angle about the X-axis and Y-axis gyro sensor 31 detects Based on this, the floating amount is calculated, and the position of the navigation sensor 30 is corrected.

  As described above, according to this embodiment, since the navigation sensor 30 is lifted, the position of the navigation sensor 30 can be corrected even when the resolution of the movement amount changes.

<Other application examples>
The best mode for carrying out the present invention has been described above with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the scope of the present invention. And substitutions can be added.

  For example, the constituent elements of the SoC 50 and the ASIC / FPGA 40 described above may be included in any of them depending on the CPU performance, the circuit scale of the ASIC / FPGA 40, and the like.

  In the present embodiment, it has been described that an image is formed by ejecting ink. However, an image may be formed by irradiation with visible light, ultraviolet light, infrared light, laser, or the like. In this case, for example, a print medium 12 that reacts to heat or light is used. Further, a transparent liquid may be discharged. In this case, visible information is obtained when light in a specific wavelength region is irradiated. Further, metal paste, resin, or the like may be discharged.

  In the present embodiment, the gyro sensor 31 detects the posture of the print medium 12. However, the horizontal posture (orientation) can also be detected by the geomagnetic sensor.

  Moreover, the gyro sensor 31 is not restricted to one, and two or more gyro sensors 31 may be installed.

The navigation sensor S ₀ is an example of a movement amount detection unit, the gyro sensor 31 is an example of a posture detection unit, and the position calculation circuit 34 is an example of a position calculation unit. The print / sensor timing generation unit 43 is an example of a timing notification unit, the IJ recording head control unit 44 and the like are an example of a droplet discharge unit, and the HMP 20 is an example of a droplet discharge device. The CPU 33, the position calculation circuit 34, and the gyro sensor 31 are an example of a floating amount calculation unit.

Further, a device having a minimum function necessary for calculating the position in the HMP 20 is a position detection device. For example, it includes a navigation sensor S ₀ , a gyro sensor 31, a position calculation circuit 34, and a CPU 33. In other words, the HMP 20 that does not have a function necessary for image formation is the position detection device. Further, a device on which the position detection device is mounted is a mounted object, and the HMP 20 is an example of a mounted object.

DESCRIPTION OF SYMBOLS 11 Image data output device 12 Print medium 25 Control part 30 Navigation sensor 31 Gyro sensor 33 CPU
34 Position Calculation Circuit 42 Navigation Sensor I / F
43 Sensor timing generator 45 Gyro sensor I / F
61 Nozzle 70 Printed circuit board

Special table 2010-522650 gazette

Claims (13)

A position detection device for detecting a position on a moving surface of a mounted object on which a position detection device is mounted,
A moving amount detecting means for detecting a moving amount on the moving surface;
Attitude detection means for detecting the attitude of the mounted object on at least the moving surface;
Position calculating means for calculating the position of the mounted object based on the movement amount and the posture;
A position detecting device. Timing notification means for notifying the movement amount detection means and the posture detection means of timing;
The position detection device according to claim 1, wherein the timing notification unit notifies the posture detection unit of a timing for detecting the posture at the same timing as the movement amount detection unit detects the movement amount.   The position detection device according to claim 1, wherein the movement amount detection unit and the posture detection unit are arranged on one substrate.   The position detection device according to any one of claims 1 to 3, wherein the posture detection means is disposed at an end when the mounted object is viewed from above.   The position detection device according to claim 1, wherein the posture detection unit is arranged on a substrate different from a substrate on which a heating element inside the mounted object is arranged.   The position detection device according to claim 1, wherein the posture detection unit is arranged on a bottom surface of the mounted object. A floating amount calculating means for calculating a floating amount from the moving surface of the mounted object from the posture of the mounted object detected by the posture detecting means;
The position detection device according to claim 1, wherein the position calculation unit corrects the movement amount detected by the movement amount detection unit according to the floating amount calculated by the floating amount calculation unit. The position detection device according to any one of claims 1 to 7,
Droplet discharge means for discharging droplets for forming an image at the position according to the position of the mounted object;
A droplet discharge device having   The liquid droplet ejection apparatus according to claim 8, wherein one movement amount detection unit and the liquid droplet ejection unit are disposed adjacent to each other. The droplet discharge means has a plurality of droplet discharge portions arranged in a row,
The droplet discharge device according to claim 8, wherein the movement amount detection unit is arranged adjacent to a direction perpendicular to the row of the droplet discharge units. The droplet discharge means has a plurality of droplet discharge portions arranged in a row,
The droplet discharge device according to claim 8, wherein the movement amount detection unit is disposed adjacent to the row of the droplet discharge units in series. When the mounting object is scanned over a print medium by a person,
The droplet discharge device according to any one of claims 8 to 11, wherein the posture detection means is disposed on the front side as viewed from a person and substantially in the center in the width direction. A position detection device that detects the position on the moving surface of the mounted object on which the position detection device is mounted,
A moving amount detecting means for detecting a moving amount on the moving surface;
Attitude detection means for detecting the attitude of the mounted object on at least the moving surface;
Position calculating means for calculating the position of the mounted object based on the movement amount and the posture;
Program to function as.