JP2015020373A - Printer, gap determination method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem such that when a paper gap in a printer is measured by a manual operation, a lot of time and labor are taken.SOLUTION: A printer includes: a printing head in which an ink ejection part for ejecting an ink onto a printing medium is formed; a sensor which irradiates a predetermined pattern formed on a printing medium with light, receives reflected light from the pattern and outputs a signal according to an intensity of the reflected light; a move part for moving the sensor with respect to the pattern; and a gap determination part 65 for determining a paper gap which represents a space between the ink ejection part and the printing medium. A spot diameter of light radiated onto the pattern from the sensor changes according to a paper gap, and the gap determination part 65 determines the paper gap on the basis of a signal outputted from the sensor which moves with respect to the pattern.

Description

  The present invention relates to a printing apparatus, a gap determination method, and a program.

  Some ink jet printers are configured to be able to adjust an interval (hereinafter referred to as a “gap”) between an ink discharge portion of a print head that discharges ink and a print medium or a platen. As a gap measurement method for adjusting the gap, for example, in Patent Document 1, in various printers including an ink jet printer, an operator inserts a measurement gauge between a print head and a platen, thereby forming the gap. I am trying to measure. In addition, there is a method in which a gap is measured and automatically adjusted by mounting a dedicated sensor for measuring the gap in the printer instead of manual work as in Patent Document 1.

JP 2009-143227 A

  However, when the gap is manually measured as in Patent Document 1, much labor and time are required for the measurement. In particular, in the case of a wide printer such as a large format printer, it is difficult to provide an accurate gap measurement value in a short time by providing many measurement points in the main scanning direction. In addition, when a dedicated sensor for measuring the gap is provided in the printer, a large-scale mechanism is required to cope with the dedicated sensor and the like, resulting in an increase in manufacturing cost of the printer.

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

  [Application Example 1] Light is applied to a print head in which an ink discharge unit that discharges ink to a print medium is formed, and a predetermined pattern formed on the print medium, and reflected light from the pattern is received. A sensor that outputs a signal corresponding to the intensity of the reflected light, a moving unit that moves the sensor with respect to the pattern, and a gap determination that determines a paper gap that represents an interval between the ink ejection unit and the printing medium. A spot diameter of light emitted from the sensor onto the pattern changes according to the paper gap, and the gap determination unit outputs from the sensor that moves relative to the pattern. A printing apparatus, wherein the paper gap is determined based on a signal level.

  According to the printing apparatus described above, the spot diameter of light emitted from the sensor onto the pattern of the printing medium changes according to the paper gap. For this reason, the target range of the pattern in which the sensor receives reflected light also changes according to the paper gap, and the output signal level of the sensor also changes according to the paper gap. This makes it possible to automatically determine the paper gap based on the output signal level of the sensor. Further, since the sensor is a mechanism for reading a pattern printed on a print medium, for example, the sensor can be used as a sensor for reading a pattern and performing correction processing (calibration) according to the read result. Thereby, it can suppress that the increase in manufacturing cost is caused for the correspondence of paper gap determination.

  Application Example 2 The printing apparatus, wherein the predetermined pattern is obtained by alternately arranging regions having different densities in the movement direction of the sensor.

  According to the printing apparatus described above, the reflected light of the pattern can be received while the sensor moves on the pattern in which the regions having different densities are alternately arranged. Therefore, a signal corresponding to the intensity of the reflected light can be output from the sensor for each of the regions having different densities set at a plurality of locations on the print medium. Thus, for example, even for a wide printer such as a large format printer, accurate paper gap measurement values can be obtained in a short time by setting regions having different densities at a plurality of locations on a wide print medium. it can.

  [Application Example 3] The printing apparatus, wherein the gap determination unit determines the paper gap based on a gradual change in the output signal level when the sensor moves in the regions having different densities. .

  According to the printing apparatus described above, when the sensor moves from one of the regions having different densities on the pattern to the other and outputs a signal, the output signal level changes according to the paper gap. The paper gap can be determined based on the change in the output signal level at this time.

  Application Example 4 The gap determination unit is configured based on the first and second changes in the output signal level when the paper gap is maximum and the first and second changes in the output signal level when the paper gap is minimum. The printing apparatus according to claim 1, wherein the paper gap is determined using a function.

  According to the printing apparatus described above, based on the correlation between the maximum paper gap and the gradual change of the output signal level, and the correlation between the minimum paper gap and the gradual change of the output signal level, the paper gap And a linear function representing the correlation between the change of the output signal level and the rate of change of the output signal level. Thereby, a paper gap can be determined using this linear function.

  Application Example 5 The printing apparatus described above, wherein each of the regions having different densities is printed on the print medium.

  According to the printing apparatus described above, each of the regions having different densities is printed on the print medium. By printing both areas with different densities, one of the areas with different densities is printed and the amount of ink printed on the print medium is greater than when the other is not printed and is used as the base of the print medium. It can be adapted to the usage pattern.

  Application Example 6 A gap adjustment mechanism for adjusting the paper gap is further provided, and the gap adjustment mechanism adjusts the paper gap based on the paper gap determined by the gap determination unit. The printing apparatus.

  According to the printing apparatus described above, the gap adjustment mechanism adjusts the paper gap based on the paper gap determined by the gap determination unit. Thus, after the paper gap is automatically acquired, the paper gap can be automatically adjusted to an appropriate state.

  [Application Example 7] Light is applied to a print head in which an ink discharge unit that discharges ink to a print medium is formed, and a predetermined pattern formed on the print medium, and reflected light from the pattern is received. In a printing apparatus having a sensor that outputs a signal corresponding to the intensity of the reflected light and a moving unit that moves the sensor with respect to the pattern, a paper that represents an interval between the ink ejection unit and the printing medium A gap determination method for determining a gap, wherein a spot diameter of light irradiated on the pattern from the sensor changes according to the paper gap, and the gap determination method moves the pattern with respect to the pattern. A gap determination method comprising: determining the paper gap based on an output signal level from a sensor.

  According to the gap determination method described above, the spot diameter of the light emitted from the sensor onto the pattern of the print medium changes according to the paper gap. For this reason, the target range of the pattern in which the sensor receives reflected light also changes according to the paper gap, and the output signal level of the sensor also changes according to the paper gap. This makes it possible to automatically determine the paper gap based on the output signal level of the sensor. Further, since the sensor is a mechanism for reading a pattern printed on a print medium, for example, the sensor can be used as a sensor for reading a pattern and performing correction processing (calibration) according to the read result. Thereby, it can suppress that the increase in manufacturing cost is caused for the correspondence of paper gap determination.

  Application Example 8 Light is applied to a print head on which an ink discharge unit that discharges ink to a print medium is formed, and a predetermined pattern formed on the print medium, and reflected light from the pattern is received. In a printing apparatus having a sensor that outputs a signal corresponding to the intensity of the reflected light and a moving unit that moves the sensor with respect to the pattern, a paper that represents an interval between the ink ejection unit and the printing medium A program for determining a gap, wherein a spot diameter of light emitted from the sensor onto the pattern changes according to the paper gap, and the program outputs an output from the sensor that moves relative to the pattern. A program for determining the paper gap based on a signal level.

  According to the above-described program, the spot diameter of light emitted from the sensor onto the pattern of the print medium changes according to the paper gap. For this reason, the target range of the pattern in which the sensor receives reflected light also changes according to the paper gap, and the output signal level of the sensor also changes according to the paper gap. This makes it possible to automatically determine the paper gap based on the output signal level of the sensor. Further, since the sensor is a mechanism for reading a pattern printed on a print medium, for example, the sensor can be used as a sensor for reading a pattern and performing correction processing (calibration) according to the read result. Thereby, it can suppress that the increase in manufacturing cost is caused for the correspondence of paper gap determination.

FIG. 2 is a diagram illustrating a schematic configuration of a printer. The block diagram of the whole structure of a printer. FIG. 2 is a diagram illustrating a schematic configuration of a main part of a printer. Explanatory drawing which shows the arrangement | sequence of the nozzle and the optical sensor in the lower surface of a head. Explanatory drawing which shows the structure of an optical sensor typically. FIG. 4 is a diagram illustrating an example of a measurement pattern formed on a sheet. Explanatory drawing of the spot irradiated to the pattern for a measurement from an optical sensor. The figure which shows the change of an output signal level when an optical sensor moves, and the pattern for a measurement is read. The graph which shows the correlation of the angle of a waveform, and a paper gap. FIG. 10 is a diagram illustrating an example of a measurement pattern printed on a sheet in Modification Example 1. Explanatory drawing of the spot irradiated to the pattern for a measurement from the optical sensor in the modification 1. FIG.

  Hereinafter, a printing apparatus according to the present embodiment will be described with reference to the drawings.

<Printer configuration>
FIG. 1 is a diagram illustrating a schematic configuration of a printer 1 as a printing apparatus according to the present embodiment. As shown in FIG. 1, the printer 1 is connected to a computer 110 by a USB cable or the like. The computer 110 functions as a print control device that supplies print data to the printer 1 and controls printing operations in the printer 1. The printer 1 is an inkjet printer (Large Format Printer: LFP) that prints an image by ejecting ink to form ink dots on a print medium. In the present embodiment, paper S or the like is used as a print medium.

  FIG. 2 is a block diagram of the overall configuration of the printer 1. FIG. 3A is a perspective view illustrating a schematic configuration of a main part of the printer 1. FIG. 3B is a cross-sectional view illustrating a schematic configuration of a main part of the printer 1. Hereinafter, a basic configuration of the printer 1 will be described.

  The printer 1 includes a transport unit 20, a carriage unit 30, a head unit 40, a detector group 50, and a controller 60. The printer 1 that has received print data from the computer 110 that is an external device controls each unit (the conveyance unit 20, the carriage unit 30, and the head unit 40) by the controller 60. The situation in the printer 1 is monitored by the detector group 50, and the detector group 50 outputs the detection result to the controller 60.

  The transport unit 20 is for transporting a print medium (for example, the paper S) in the transport direction. The transport unit 20 includes a paper feed roller 21, a transport motor (not shown), a transport roller 23, a platen 24, and a paper discharge roller 25. The paper feed roller 21 is a roller for feeding the print medium inserted into the paper insertion slot into the printer 1. The transport roller 23 is a roller that transports the print medium fed by the paper feed roller 21 to a printable area, and is driven by a transport motor. The platen 24 supports the printing medium being printed. The paper discharge roller 25 is a roller for discharging the print medium to the outside of the printer 1 and is provided on the downstream side in the transport direction with respect to the printable area.

  The carriage unit 30 (moving unit) is for moving (also referred to as “scanning”) the head in a direction crossing the transport direction (hereinafter referred to as “moving direction”). The carriage unit 30 includes a carriage 31, a carriage motor 32, a carriage shaft 33, and a gap adjustment mechanism 35. The carriage 31 is slidably held on the carriage shaft 33 and can reciprocate in the moving direction, and is driven by a carriage motor 32. The carriage 31 detachably holds an ink cartridge that stores ink. The gap adjusting mechanism 35 is a mechanism for adjusting the height of the carriage shaft 33, that is, the head in the vertical direction. The gap adjusting mechanism 35 adjusts the height of the carriage shaft 33 by the gear 36, the cam 37, the fixing pin 38, and the like.

  The head unit 40 is for ejecting ink onto a print medium. The head unit 40 includes a head 41 having a plurality of nozzles. Since the head 41 is provided on the carriage 31, when the carriage 31 moves in the movement direction, the head 41 also moves in the movement direction. Then, by intermittently ejecting ink while the head 41 is moving in the moving direction, dot lines (raster lines) along the moving direction are formed on the print medium.

  The detector group 50 includes a linear encoder 51, a rotary encoder 52, a paper detection sensor 53, an optical sensor 54, and the like. The linear encoder 51 detects the position of the carriage 31 in the moving direction. The rotary encoder 52 detects the rotation amount of the transport roller 23. The paper detection sensor 53 detects the position of the leading edge of the print medium being fed. The optical sensor 54 reads a pattern formed on the print medium by using a light emitting unit that is a light source and a light receiving unit that is a light receiving sensor attached to the carriage 31. Details of the light emitting unit and the light receiving unit will be described later.

  The controller 60 is a control unit for controlling the printer 1. The controller 60 includes an interface (I / F) unit 61, a CPU 62, a memory 63, a unit control circuit 64, and a gap determination unit 65. The interface unit 61 transmits and receives data between the computer 110 and the printer 1. The CPU 62 is an arithmetic processing unit for controlling the entire printer. The memory 63 is for securing an area for storing a program of the CPU 62, a work area, and the like, and includes storage elements such as a RAM and an EEPROM. The CPU 62 controls each unit via the unit control circuit 64 in accordance with a program stored in the memory 63. The gap determination unit 65 determines the vertical distance between the lower surface (ink ejection unit) of the head 41 and the print medium (hereinafter referred to as “paper gap”) based on the signal output by the optical sensor 54 reading the measurement pattern. judge. Details of the determination method in the gap determination unit 65 will be described later.

  FIG. 4 is an explanatory diagram showing the arrangement of nozzles and the optical sensor 54 on the lower surface of the head 41. On the lower surface of the head 41, a black ink nozzle group K, a cyan ink nozzle group C, a magenta ink nozzle group M, and a yellow ink nozzle group Y are formed. Each nozzle group includes a plurality (180 in this case) of nozzles that are ejection openings for ejecting ink of each color.

The plurality of nozzles of each nozzle group are aligned at a constant interval (nozzle pitch: k · D) along the transport direction. Here, D is the minimum dot pitch in the carrying direction (that is, the interval at the highest resolution of dots formed on the print medium). K is an integer of 1 or more. For example, when the nozzle pitch is 180 dpi (1/180 inch) and the dot pitch in the transport direction is 720 dpi (1/720 inch), k = 4. The nozzles of each nozzle group are assigned a smaller number as the nozzles on the downstream side (# 1 to # 180). That is, the nozzle # 1 is located downstream of the nozzle # 180 in the transport direction. The position of the optical sensor 54 in the transport direction is further downstream in the transport direction than the nozzle # 1 located on the most downstream side.
The ejection method for ejecting ink from the nozzle may be a method for ejecting ink using a piezoelectric element (piezo element), or a method for generating bubbles in the nozzle by heat. Other methods may be used.

<Configuration of optical sensor>
FIG. 5 is an explanatory diagram schematically showing the configuration of the optical sensor 54. As shown in FIG. 5, the optical sensor 54 includes a light emitting unit 55 and a light receiving unit 56. The light emitting unit 55 is a light emitting device for irradiating light toward a print medium (hereinafter described as “paper S”). For the light emitting unit 55, a light emitting device such as a light emitting diode, a laser diode, or an incandescent bulb can be used. The light receiving unit 56 is a photoelectric conversion device that detects reflected light reflected by the paper S and converts it into an electrical signal. A photodiode, a phototransistor, or the like can be used as the light receiving element.

  The irradiation light emitted from the light emitting unit 55 is reflected by the paper S, and the diffuse reflection component of the reflected light reaches the light receiving unit 56. The intensity of the reflected light depends on the color density at the reflection position of the paper S. The light receiving unit 56 generates an electrical signal corresponding to the intensity of the reflected light and outputs it as an output signal to the controller 60. In the present embodiment, the optical sensor 54 has a low output signal level when the density is high (dark), and conversely, the output signal level becomes high when the density is low (bright).

  Here, when the irradiation light from the light emitting unit 55 is focused on the surface of the paper S, a region where the paper S is irradiated by the irradiation light is referred to as a spot. In FIG. 5, the spot diameter is shown as a spot diameter d. In the present embodiment, the lower surface of the head 41 shown in FIG. 3B and the lower surface of the optical sensor 54 have the same height in the downward direction, and as shown in FIG. The paper gap g is the distance from S, that is, the vertical distance between the lower surface of the head 41 and the paper S. In FIG. 5, the larger the paper gap g, the longer the optical path from the light emitting section 55 to the paper S, and the larger the spot diameter d. Conversely, the smaller the paper gap g is, the shorter the optical path from the light emitting portion 55 to the paper S is, so the spot diameter d becomes smaller.

  In the present embodiment, the optical sensor 54 is used for measuring the paper gap, but is not limited thereto. For example, it is also possible to use a sensor for reading a density correction pattern and performing correction processing (calibration) according to the read result.

  Further, in the present embodiment, in the optical sensor 54, the direction of the light emitting unit 55 is set so that the irradiation light is irradiated obliquely with respect to the surface of the paper S, but is not limited thereto. For example, the direction of the light emitting unit 55 may be set so that the irradiation light is irradiated perpendicularly to the surface of the paper S. Moreover, although the optical sensor 54 of this embodiment is comprised including the light emission part 55 and the light-receiving part 56, it is not restricted to this. For example, the optical sensor 54 may be configured separately as a light emitting device and a light receiving device.

<Read pattern>
FIG. 6 is a diagram illustrating an example of a measurement pattern formed on the paper S in order to measure the gap. The measurement pattern PT10 shown in FIG. 6 has a checkered pattern in which square-shaped black regions PT11 and white regions PT12 are alternately arranged in the moving direction. The vertical and horizontal widths of the black regions PT11 and the white regions PT12 are the same size. Further, the white area PT12 is an area in which the background of the paper is used as it is. When the optical sensor 54 moves together with the head 41 in the movement direction, the optical sensor 54 sequentially reads the black region PT11 and the white region PT12 of the measurement pattern PT10 one by one.

  FIG. 7 is an explanatory diagram of spots irradiated from the optical sensor 54 to the measurement pattern PT10. FIG. 7A shows each spot s1 that is irradiated to the measurement pattern PT10 while the optical sensor 54 moves in the moving direction in the state of the paper gap (also referred to as “PG”) g1. FIG. 7B shows each spot s2 irradiated to the measurement pattern PT10 while the optical sensor 54 moves in the moving direction in the state of the paper gap g2. Here, it is assumed that the paper gap g2 is larger than the paper gap g1. That is, the distance between the lower surface of the head 41 and the paper S is larger in FIG. 7B than in FIG. For this reason, the spot diameter d2 of the spot s2 shown in FIG. 7B is larger than the spot diameter d1 of the spot s1 shown in FIG. That is, the spot diameter of the spot irradiated from the optical sensor 54 changes according to the paper gap. In the case of FIG. 7, the spot on the surface of the paper S increases as the paper gap increases. Note that the spot irradiated from the optical sensor 54 to the measurement pattern PT10 is not limited to the example shown in FIGS. 7A and 7B. For example, the distance between the spots may be smaller or larger. Further, the spots may partially overlap each other.

  In the state of the paper gap g1 shown in FIG. 7A, the light emitting unit 55 of the optical sensor 54 irradiates each spot s1 to the measurement pattern PT10 while moving in the moving direction, and the light receiving unit 56 receives each spot s1. An output signal corresponding to the intensity of the reflected light from is output to the controller 60. On the other hand, in the state of the paper gap g2 shown in FIG. 7B, the light emitting unit 55 irradiates the measurement pattern PT10 with each spot s2 while moving in the moving direction, and the light receiving unit 56 receives light from each spot s2. An output signal corresponding to the intensity of the reflected light is output to the controller 60.

  FIG. 8 is a diagram illustrating a change in the output signal level when the measurement pattern PT10 is read while the optical sensor 54 is moving. FIG. 8A shows a change in the output signal level of the reflected light from the spot s1 irradiated while the optical sensor 54 moves in the moving direction in the state of the paper gap g1 shown in FIG. 7A. FIG. 8B shows a change in the output signal level of the reflected light from the spot s2 irradiated while the optical sensor 54 moves in the moving direction in the state of the paper gap g2 shown in FIG. 7B. As shown in the waveforms of FIGS. 8A and 8B, the output signal level is high in the white region PT12, and conversely, the output signal level is low in the black region PT11. Further, when the white region PT12 shifts to the black region PT11, the output signal level gradually decreases with the inclination of the angle a1 in FIG. 8A and with the inclination of the angle a2 in FIG. 8B. On the other hand, when shifting from the black region PT11 to the white region PT12, the output signal level gradually increases with the same inclination. Here, the angle a2 shown in FIG. 8B is smaller than the angle a1 shown in FIG. That is, the change in the output signal level shown in the waveform of FIG. 8A is abrupt, and the change in the output signal level shown in the waveform of FIG. 8B is gentler than that. When comparing each of FIGS. 7A and 7B, the region of FIG. 7B having a larger spot diameter is closer to the region adjacent to the moving direction than FIG. 7A having a smaller spot diameter. By being affected for a longer time.

  FIG. 9 is a graph showing the correlation between the angle of the waveform shown in FIG. 8 and the paper gap. The horizontal axis of the graph indicates the above-described angle in the waveforms as shown in FIGS. 8A and 8B, and the angle increases toward the right in the figure. The vertical axis of the graph indicates the paper gap, and the gap increases as it goes upward in the figure. Further, Max shown on the vertical axis of the graph is the maximum value of the paper gap in the printer 1, and Min is the minimum value of the paper gap. In FIG. 9, the angle of the waveform is minimized when the paper gap is Max. As the paper gap becomes smaller, the waveform angle decreases with the inclination of the linear line, and the waveform angle becomes maximum when the paper gap is Min. Therefore, the paper gap can be determined by executing a linear function calculation of paper gap = f (waveform angle). In the case of FIG. 9, the paper gap Gs is calculated in the case of the waveform angle As. Here, it is assumed that the relationship between the paper gap Max and the waveform angle and the paper gap Min and the waveform angle in FIG. 9 is preset when the printer 1 is shipped from the factory.

  In the above-described embodiment, while the optical sensor 54 moves in the moving direction, the measurement pattern PT10 in which the black region PT11 and the white region PT12 are arranged is irradiated with light, and the reflected light is output from the black region PT11 and the white region PT12. The paper gap is determined based on the change in signal level. This is because the size of the spot diameter irradiated on the measurement pattern PT10 is proportional to the size of the paper gap. Thus, the paper gap can be automatically determined by the optical sensor 54 reading the measurement pattern PT10. Further, the controller 60 controls the gap adjustment mechanism 35 of the carriage unit 30 based on the determination result, so that the gap adjustment can be automatically executed.

(Modification 1)
In the above-described embodiment, the paper gap is determined using the gradual change in the output signal level of the reflected light from the measurement pattern (angles a1 and a2 shown in FIG. 8). However, the method is not limited to the method using the gradual change of the output signal level. For example, FIG. 10 is a diagram illustrating an example of a measurement pattern printed on the paper S in the first modification. The measurement pattern PT20 shown in FIG. 10 has a polka dot pattern in which circular black regions PT21 are arranged in the moving direction with the white region PT22 interposed therebetween. FIG. 11 is an explanatory diagram of spots irradiated from the optical sensor 54 to the measurement pattern PT20. FIG. 11A shows each spot s1 that irradiates the measurement pattern PT20 while the optical sensor 54 moves in the moving direction in the state of the paper gap g1. FIG. 11B shows each spot s2 irradiated on the measurement pattern PT20 while the optical sensor 54 moves in the movement direction in the state of the paper gap g2. Here, it is assumed that the paper gap g2 is larger than the paper gap g1.

  As shown in FIG. 11, the spot diameter d2 shown in FIG. 11 (b) is larger than the spot diameter d1 shown in FIG. 11 (a). For this reason, the ratio of the black area PT21 occupying the spot s1 area shown in FIG. 11A is larger than the ratio of the black area PT21 occupying the spot s2 area shown in FIG. That is, the ratio of the black region PT21 occupying the spot region irradiated from the optical sensor 54 changes according to the paper gap. In the case of FIG. 11, the larger the paper gap, the larger the black region PT21 occupying the spot region. The ratio becomes smaller. Thereby, the paper gap can be determined using the correlation between the paper gap and the ratio. Note that the black region PT21 is not limited to a circular shape, and may be an arbitrary shape.

(Modification 2)
In the embodiment described above, it is possible to use a measurement pattern formed in advance on the paper S. However, the printer 1 may be used to print the measurement pattern PT10. In this case, the black region PT11 is printed with black ink, but the white region PT12 may be used without printing anything, and the background of the paper may be used as it is. For example, printing may be performed using white ink or yellow ink. Also good. In the case of a user who prints paper with a large amount of ink per line, a phenomenon (cockling) in which the paper deforms so as to wave may occur. When both the black region PT11 and the white region PT12 are printed, the paper gap can be measured more accurately in accordance with the actual usage of the user.

(Modification 3)
In the embodiment described above, the printer 1 is described as the printing apparatus. However, the present invention is not limited to this, and it is embodied in a liquid ejecting apparatus that ejects or ejects fluid other than ink (liquid, liquid material in which particles of functional material are dispersed, or a fluid such as gel). It can also be converted. For example, color filter manufacturing apparatus, dyeing apparatus, fine processing apparatus, semiconductor manufacturing apparatus, surface processing apparatus, three-dimensional modeling machine, gas vaporizer, organic EL manufacturing apparatus (especially polymer EL manufacturing apparatus), display manufacturing apparatus, film formation The same technology as that of the above-described embodiment may be applied to various devices to which inkjet technology is applied, such as a device and a DNA chip manufacturing device. These methods and manufacturing methods are also within the scope of application.

  DESCRIPTION OF SYMBOLS 1 ... Printer, 20 ... Conveyance unit, 23 ... Conveyance roller, 24 ... Platen, 25 ... Discharge roller, 30 ... Carriage unit, 31 ... Carriage, 32 ... Carriage motor, 33 ... Carriage shaft, 35 ... Gap adjustment mechanism, 36 ... Gear, 37 ... Cam, 38 ... Fixing pin, 40 ... Head unit, 41 ... Head, 50 ... Detector group, 51 ... Linear encoder, 52 ... Rotary encoder, 53 ... Paper detection sensor, 54 ... Optical sensor, 55 ... Light emitting unit, 56 ... Light receiving unit, 60 ... Controller, 61 ... Interface (I / F) unit, 62 ... CPU, 63 ... Memory, 64 ... Unit control circuit, 65 ... Gap determination unit, 110 ... Computer.

Claims (8)

A print head in which an ink discharge portion for discharging ink to a print medium is formed;
A sensor that irradiates a predetermined pattern formed on the print medium with light, receives reflected light from the pattern, and outputs a signal according to the intensity of the reflected light;
A moving unit that moves the sensor relative to the pattern;
A gap determination unit that determines a paper gap that represents an interval between the ink discharge unit and the print medium;
The spot diameter of light emitted from the sensor onto the pattern changes according to the paper gap, and the gap determination unit is configured to output the paper based on an output signal level from the sensor that moves relative to the pattern. A printing apparatus characterized by determining a gap.   The printing apparatus according to claim 1, wherein the predetermined pattern is obtained by alternately arranging regions having different densities in a moving direction of the sensor.   The printing apparatus according to claim 2, wherein the gap determination unit determines the paper gap based on a change in the output signal level when the sensor moves in the regions having different densities. .   The gap determination unit uses a linear function based on a gradual change of the output signal level when the paper gap is maximum and a gradual change of the output signal level when the paper gap is minimum. The printing apparatus according to claim 3, wherein a paper gap is determined.   5. The printing apparatus according to claim 2, wherein each of the regions having different densities is printed on the print medium. A gap adjusting mechanism for adjusting the paper gap;
The printing apparatus according to claim 1, wherein the gap adjustment mechanism adjusts the paper gap based on the paper gap determined by the gap determination unit. A print head in which an ink discharge portion for discharging ink to a print medium is formed;
A sensor that irradiates a predetermined pattern formed on the print medium with light, receives reflected light from the pattern, and outputs a signal according to the intensity of the reflected light;
In a printing apparatus having a moving unit that moves the sensor with respect to the pattern,
A gap determination method for determining a paper gap representing an interval between the ink ejection unit and the print medium,
The spot diameter of light emitted from the sensor onto the pattern changes according to the paper gap. In the gap determination method, the paper is based on the output signal level from the sensor that moves relative to the pattern. A gap determination method characterized by determining a gap. A print head in which an ink discharge portion for discharging ink to a print medium is formed;
A sensor that irradiates a predetermined pattern formed on the print medium with light, receives reflected light from the pattern, and outputs a signal according to the intensity of the reflected light;
In a printing apparatus having a moving unit that moves the sensor with respect to the pattern,
A program for determining a paper gap representing an interval between the ink ejection unit and the printing medium,
The spot diameter of light emitted from the sensor onto the pattern changes according to the paper gap, and the program sets the paper gap based on the output signal level from the sensor that moves relative to the pattern. A program characterized by judging.

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