JP2005066415A - Droplet observation method and droplet observation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a droplet observation method which efficiently and precisely observes droplets which are discharged and flown from a plurality of nozzles of a droplet discharging head, and also provide a droplet observation device. <P>SOLUTION: The droplet observation device 1 observes the droplets 200 which are discharged and flown from the six nozzles 101 of the droplet discharging head 100. The droplet observation device 1 moves the droplet discharging head 100 pitch by pitch in the direction of the arrangement of the six nozzles 101 so that states in which the trajectories of the droplets 200 cross the laser beams 233 and 234 may sequentially be obtained for each nozzle 101 by moving the droplet discharging head 100 to the laser beams 233 and 234 based on information on the position of each nozzle 101. During that time, the droplet observation device sequentially observes the droplets 200 thus discharged for the nozzles 101, in which the trajectories of the droplets 200 cross the laser beams 233 and 234, based on the output signal of a light receiving means 4 receiving the laser beams 233 and 234. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a droplet observation method and a droplet observation apparatus that can observe a droplet ejected from a nozzle hole of a droplet ejection head and flying.

In recent years, liquid crystal display devices, alignment film devices, overcoat devices, organic EL (Electro-Luminescence) devices, electron emission devices, PDP (Plasma Display Panel) devices, electrophoretic display devices, resist devices using droplet discharge devices It has been proposed to produce microlens arrays, metal wiring, products in the bio field, and the like.
In such a droplet discharge device, since it is necessary to land each droplet at an accurate position on the workpiece, when controlling the droplet discharge device, or when developing or designing the droplet discharge device, etc. In this case, it is necessary to observe the flight state (for example, flight speed, flight direction, landing position, etc.) of the droplet ejected from the nozzle hole of the droplet ejection head.

Conventionally, when observing the flight state of a flying droplet, a laser beam is irradiated to the droplet by an imaging optical device having a laser beam irradiation unit (semiconductor laser) and a light receiving element (photodiode), and the irradiated laser The amount of light received by a light receiving element that receives light is measured to observe the flight state (see, for example, Patent Document 1).
By the way, in order to observe the flight state of the droplet, it is necessary to align the position of the nozzle hole from which the droplet to be observed is ejected with the laser beam irradiation unit and the light receiving element. However, a large number of nozzle holes (for example, 180) are formed in the droplet discharge head, and each time the position of the droplets discharged from different nozzle holes is observed, this alignment is set to a different nozzle. There is a problem that it is necessary to carry out every hole.
In addition, since this positioning is performed manually, there is a problem that it takes time and variation in positional accuracy occurs.

JP 2002-48810 A

  An object of the present invention is to provide a droplet observation method and a droplet observation device capable of efficiently and accurately observing droplets ejected from a plurality of nozzle holes of a droplet ejection head and flying. is there.

Such an object is achieved by the present invention described below.
The droplet observation method of the present invention is a droplet observation method for observing droplets ejected from a plurality of nozzle holes provided in a droplet ejection head and flying.
While irradiating at least one laser beam from the laser beam irradiation unit in a direction crossing the flight direction of the droplet, and detecting the output signal of the light receiving unit that receives the laser beam and performs photoelectric conversion,
By moving the droplet discharge head relative to the laser light irradiation means based on the information on the position of each nozzle hole, the state in which the trajectory of the droplet intersects the laser light is the plurality of nozzle holes. The droplet discharge heads are relatively pitch-fed along the arrangement direction of the plurality of nozzle holes so that the nozzle trajectory of the droplet intersects the laser light. Information on the ejected liquid droplets is obtained based on the output signal of the light receiving means, whereby the liquid droplets are sequentially observed for the plurality of nozzle holes.
Thereby, it is possible to efficiently and accurately observe the droplets ejected from the plurality of nozzle holes of the droplet ejection head and flying.

The droplet observation device of the present invention is a droplet observation device for observing a droplet ejected from a plurality of nozzle holes provided in a droplet ejection head and flying.
Laser light irradiation means for irradiating at least one laser light in a direction crossing the flight direction of the droplets;
A light receiving means for receiving the laser beam and performing photoelectric conversion;
Based on the output signal of the light receiving means, a droplet observing means for obtaining information about a droplet ejected from a nozzle hole to be observed;
Moving means for moving the droplet discharge head relative to the laser light irradiation means along the arrangement direction of the plurality of nozzle holes;
Control means for controlling the operation of the moving means;
Nozzle position detecting means for detecting the position of the nozzle hole,
By operating the moving means based on the information regarding the position of each nozzle hole detected by the nozzle hole position detecting means, the state in which the trajectory of the droplet intersects the laser beam is sequentially applied to the plurality of nozzle holes. The droplet discharge head is relatively pitch-fed so as to obtain, during which the droplet observation means observes the droplet in the nozzle hole where the trajectory of the droplet intersects the laser beam, Thus, droplets are sequentially observed for the plurality of nozzle holes.
Thereby, it is possible to efficiently and accurately observe the droplets ejected from the plurality of nozzle holes of the droplet ejection head and flying.

In the droplet observation apparatus according to the aspect of the invention, the nozzle hole position detecting unit detects the position of the nozzle hole by performing image processing on the electronic image and a camera that captures an electronic image of the nozzle surface of the droplet discharge head. It is preferable to have an image processing means.
Thereby, the photographed image of the nozzle surface can be processed more accurately, and the position of the nozzle hole can be easily detected.

The droplet observation device of the present invention is a droplet observation device for observing a droplet ejected from a plurality of nozzle holes provided in a droplet ejection head and flying.
Laser light irradiation means for irradiating at least one laser light in a direction crossing the flight direction of the droplets;
A light receiving means for receiving the laser beam and performing photoelectric conversion;
Droplet observation means for observing a droplet based on an output signal of the light receiving means;
Moving means for moving the droplet discharge head relative to the laser light irradiation means along the arrangement direction of the plurality of nozzle holes;
Control means for controlling the operation of the moving means;
Storage means for storing information regarding the position of each nozzle hole,
By operating the moving means based on the information on the position of each nozzle hole stored in the storage means, a state in which the trajectory of the droplet intersects the laser light can be obtained sequentially for the plurality of nozzle holes. The droplet discharge head is relatively pitch-fed, and during that time, the droplet observation means observes the droplet with respect to the nozzle hole where the trajectory of the droplet intersects the laser beam, It is characterized in that droplets are observed sequentially for a plurality of nozzle holes.
Thereby, it is possible to efficiently and accurately observe the droplets ejected from the plurality of nozzle holes of the droplet ejection head and flying.

In the droplet observation apparatus of the present invention, the laser beam irradiation means irradiates a plurality of laser beams, and the plurality of laser beams includes a droplet trajectory corresponding to a nozzle hole to be observed. It is preferable to cross each other.
As a result, the same droplet blocks the laser beam at a plurality of locations, and this blockage causes a temporal change in the amount of laser beam received by the light receiving means. Due to this temporal change, it is possible to measure the time difference between the output signals output from the light receiving means.

In the droplet observation apparatus of the present invention, it is preferable that the droplet observation unit obtains information related to the flight speed of the droplet based on a time difference in output signal change of the light receiving unit with respect to the plurality of laser beams. .
Thereby, the flight speed of the droplet can be observed more accurately.
In the droplet observation apparatus of the present invention, it is preferable that the plurality of laser beams intersect each other.
Thereby, the flight speed of the droplet can be observed more accurately.
In the droplet observation apparatus of the present invention, it is preferable that a position where the plurality of laser beams intersect with each other and a position where the plurality of laser beams intersect with the trajectory of the droplet are different.
Thereby, the information regarding a droplet can be obtained more correctly.

Hereinafter, a droplet observation method and a droplet observation device of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
<First Embodiment>
FIG. 1 is a plan view showing a first embodiment of the droplet observation apparatus of the present invention, FIGS. 2, 3 and 6 are side views showing the first embodiment of the droplet observation apparatus of the present invention, FIG. FIG. 5 is a cross-sectional view taken along the line AA, a cross-sectional view taken along the line BB and a cross-sectional view taken along the line CC in FIG. 3, and FIG. FIG. In the following description, for convenience of explanation, unless otherwise specified, the upper part in FIGS. 2, 3 and 4 is described as “upper” and the lower part is described as “lower”. Further, the laser beam in FIG. 3 is exaggerated for convenience.

  As shown in FIGS. 1 and 2, the droplet observation apparatus 1 observes droplets 200 that are ejected from a plurality of (six in FIG. 1) nozzle holes 101 included in the droplet ejection head 100 and fly. Device. The droplet observation apparatus 1 includes a laser beam irradiating unit 2 that irradiates two laser beams 233 and 234, a light receiving unit 4 that receives the laser beams 233 and 234 and performs photoelectric conversion, and an output signal of the light receiving unit 4. Based on this, the droplet observation means 63 for obtaining information about the droplet 200, the movement means 3 for moving the droplet discharge head 100, the control means 6 for controlling the operation of the movement means 3, and the position of the nozzle hole 101 are detected. And nozzle hole position detecting means 7 for performing the above-described operation.

  As shown in FIG. 2, nozzle holes 101 are formed in the nozzle surface (nozzle plate) 102 of the droplet discharge head 100. The nozzle hole 101 is provided with a pressure chamber communicating with the nozzle hole 101 and an actuator (none of which is shown) for changing the pressure of the liquid filled in the pressure chamber. The droplet discharge head 100 discharges the liquid in the pressure chamber as the droplet 200 from the nozzle hole 101 by driving the actuator. The actuator provided in the droplet discharge head 100 is not particularly limited, and may be configured by a piezoelectric actuator or a heating element that generates bubbles by heating a liquid.

The droplet discharge head 100 is driven by a head driving unit (head driver) 300. The head driving unit 300 generates an ejection signal at a predetermined timing (driving frequency). In the droplet discharge head 100, the actuator is operated by the discharge signal input from the head driving unit 300, and the droplet 200 is discharged.
The liquid (including the dispersion liquid) discharged by the droplet discharge head 100 is not particularly limited. For example, ink, a filter material for a color filter, and a fluorescent material for forming an EL light emitting layer in an organic EL device. In order to form a fluorescent material for forming a phosphor in a PDP device, a migrating material for forming an electrophoretic material in an electrophoretic display device, a bank material for forming a bank on the surface of a substrate, various coating materials, and an electrode Liquid electrode material, particle material constituting spacer for forming a minute cell gap between two substrates, liquid metal material for forming metal wiring, lens material for forming microlens, resist material And a light diffusing material for forming a light diffuser.

  Such a droplet discharge head 100 is installed so as to be movable along the direction of arrangement of the six nozzle holes 101 (hereinafter simply referred to as “array direction”) by the guide rail 31 of the moving means 3. .

  As shown in FIG. 5, the control unit 6 controls the laser beam irradiation unit 2, the moving unit 3, the light receiving unit 4, the nozzle hole position detecting unit 7, and the head driving unit 300. The control unit 6 includes a CPU (Central Processing Unit) 61, a storage unit 62, and a droplet observation unit 63. The storage means 62 has a storage medium (recording medium) that can be read by the CPU 61, and this storage medium is composed of a magnetic or optical recording medium, a semiconductor memory, or the like.

As shown in FIGS. 1 to 3, the laser beam irradiation means 2 includes a laser beam irradiation unit 21 that irradiates a single laser beam 23, and a beam splitter that branches the laser beam 23 into a laser beam 231 and a laser beam 232. (Prism) 25, laser blade 26 that shields a part of each of laser beams 231 and 232, and lens 27.
The laser beam 23 irradiated by the operation of the laser beam irradiation means 2 is received by the light receiving means 4 while its cross section changes as shown below. FIG. 3 is a side view of a part of the droplet observation apparatus 1 (in the vicinity of the laser beam irradiation means 2) in FIG.

First, as shown in FIG. 4, the laser light 23 emitted from the laser light irradiation unit 21 has a substantially circular cross section (see FIG. 4A).
Next, when the laser beam 23 passes through the beam splitter 25, the laser beam 23 branches into a laser beam 231 and a laser beam 232. The cross sections of the laser beams 231 and 232 are almost semicircular (see FIG. 4B).

Next, when the laser beam 231 and the laser beam 232 pass through the laser blade 26, the upper part of the laser beam 231 is shielded from light, and the lower part of the laser beam 232 is shielded from light. At this time, the laser beams 231 and 232 are laser beams 233 and 234, which are band-shaped light beams, respectively, and the cross sections thereof are elongated (see FIG. 4C).
Next, the laser beams 233 and 234 are collected by the lens 27, intersect each other, and intersect the trajectory of the droplet 200 corresponding to the nozzle hole 101 to be observed (see FIG. 1).

Next, the laser beams 233 and 234 that intersect the trajectory of the droplet 200 are received by the light receiving means 4. (See FIG. 1).
With such a configuration, the same droplet 200 shields the laser beams 233 and 234, respectively, and this light shielding causes a temporal change in the amount of received light with the laser beams 233 and 234 received by the light receiving means 4. Due to this temporal change, the time difference between the output signals output from the light receiving means 4 can be measured.

As shown in FIGS. 1 and 2, the light receiving means 4 is composed of light receiving elements 433 and 434 provided vertically at a constant distance H (distance indicated by H in FIG. 2).
The light receiving elements 433 and 434 are installed on the opposite side of the lens 27 of the laser light irradiation means 2 through the flight region 400 of the droplet 200. That is, the laser beams 233 and 234 are emitted from the side opposite to the light receiving elements 433 and 434 through the flight region 400.

As shown in FIG. 5, the nozzle hole position detecting means 7 detects the position of the nozzle hole 101 by image processing the camera 71 that captures an electronic image of the nozzle surface 102 of the droplet discharge head 100. Image processing means 72.
The camera 71 has a solid-state imaging device such as a CCD (Charge Coupled Device) and a camera lens, for example, and a nozzle surface through a passing area 401 through which a laser beam in a flying area 400 where the droplet 200 flies passes. It is installed on the opposite side of 102 (see FIG. 2).
With such a configuration, the photographed image of the nozzle surface 102 can be processed more accurately, and the position of the nozzle hole 101 can be easily detected.

As shown in FIG. 1, the moving means 3 extends in the arrangement direction and is installed in the same direction as the guide rail 31 and the guide rail 31 that guides the droplet discharging head 100 in the same direction. And a servo motor 34 for applying a rotational force to the ball screw 33.
The moving means 3 operates based on information on the position of each nozzle hole 101 detected by the nozzle hole position detecting means 7.

Although it does not specifically limit as this detection, For example, it is preferable to carry out as shown below. Note that the droplet discharge head 100 moves in the direction of the arrow in FIG. 1 by the operation of the moving unit 3, but hereinafter, it is simply referred to as “the droplet discharge head 100 moves”. Further, α and p shown below are arbitrary numerical values.
First, the droplet discharge head 100 moves to a predetermined reference position (initial position) (see FIG. 6A).
Next, the droplet discharge head 100 moves from the initial position by a distance α (a distance indicated by α in FIG. 6) measured in advance, and the camera 71 captures an image of the nozzle surface 102 of the droplet discharge head 100. (See FIG. 6B).

Next, the captured image is processed by the image processing unit 72 of the nozzle hole position detecting unit 7. The image processing is not particularly limited, but binarization processing is generally used. In this case, first, the image processing means 72 binarizes the captured image of the nozzle surface 102 and extracts the region of the nozzle hole 101a. Next, the center point of this region is calculated, and this center point is set as the center point (position) of the nozzle hole 101a.
Next, the position of the droplet discharge head 100 is adjusted (moved) so that the lower flight region 400 from the center point of the nozzle hole 101a intersects the laser beams 233 and 234.

Next, the droplet discharge head 100 moves from this position to the distance (distance between pitches) p (distance indicated by p in FIG. 6) between the nozzle holes 101, and the nozzle surface 102 of the droplet discharge head 100 is moved by the camera 71. (See FIG. 6C).
Next, similarly, the center point (position) of the nozzle hole 101b is detected, and the position of the droplet discharge head 100 is adjusted.
Thereafter, this is repeated sequentially for the nozzle holes 101c (see FIG. 6D), 101d, 101e, and 101f.

  As shown in FIGS. 1 and 2, the control unit 6 operates the moving unit 3 on the basis of information on the position of each nozzle hole 101 detected by the operation of the nozzle hole position detecting unit 7, thereby causing the droplet 200. The droplet discharge head 100 is pitch-fed (moved at a pitch distance p) so that a state in which the trajectory of the nozzles intersects the laser beams 233 and 234 is sequentially obtained for the six nozzle holes 101. Meanwhile, the operation of the droplet observation means 63 observes (measures) the flight speed of the droplet 200 at the nozzle hole 101 where the trajectory of the droplet 200 intersects the laser beams 233 and 234. As a result, the droplets 200 are sequentially observed for the six nozzle holes 101. That is, the control means 6 performs the following control.

First, as described above, the position of the nozzle hole 101a is detected by the operation of the nozzle hole position detecting means 7.
Next, as described above, based on this detection, the droplet discharge head 100 moves, and the trajectory of the droplet 200a discharged from the nozzle hole 101a intersects the laser beams 233 and 234.

Next, the light receiving elements 433 and 434 receive the laser beams 233 and 234 that intersect the trajectory of the droplet 200a, respectively.
Next, the droplet observation means 63 is activated, and the flying speed of the droplet 200a is measured based on the output signals of the light receiving elements 433 and 434 that have received the laser beams 233 and 234.
Next, as described above, the position of the nozzle hole 101 b is detected by the operation of the nozzle hole position detecting means 7.

Next, as described above, based on this detection, the droplet discharge head 100 moves, and the trajectory of the droplet 200b discharged from the nozzle hole 101b intersects the laser beams 233 and 234.
Next, the light receiving elements 433 and 434 receive the laser beams 233 and 234 that intersect the trajectory of the droplet 200b, respectively.

Next, the droplet observation means 63 is activated, and the flight speed of the droplet 200b is measured based on the output signals of the light receiving elements 433 and 434 that have received the laser beams 233 and 234.
Thereafter, this is sequentially repeated for the droplets 200c, 200d, 200e, and 200f.
Thereafter, for example, in the same manner as described above, the flight speed of the droplet 200 from each nozzle hole 101 is measured from the direction opposite to the moving direction of the droplet discharge head 100 described above while returning by the distance p. May be.

With such a configuration, the droplet observation apparatus 1 changes the position of the droplet discharge head 100 based on the control of the control unit 6, thereby discharging the discharged droplet 200 in each of the six nozzle holes 101. It can be observed.
As a result, the droplet 200 ejected from the six nozzle holes 101 of the droplet ejection head 100 and flying can be observed efficiently and accurately.

As described above, the droplet observation means 63 is based on the time difference of the output signal change of the light receiving means 4 that receives the two laser beams 233 and 234, and the droplet 200 ejected from the nozzle hole 101 to be observed. It is configured to obtain information on the flight speed of the aircraft.
As a result, the distance h (distance indicated by h in FIG. 2) that the droplet 200 moves (flies) between the laser beam 233 and the laser beam 234, which has been measured in advance, is measured by the droplet observation means 63. The flying speed of the droplet 200 can be calculated by dividing by the time difference between the output signal changes of the received light receiving elements 433 and 434. The flight speed calculated in this way has less errors and is a more accurate numerical value.

In order to calculate the flying speed of the droplet 200, it is necessary to detect the droplet 200 with the light receiving element 433 and the light receiving element 434. Therefore, the laser beam 233 and the laser beam 234 intersect with each other (FIG. 2). And the positions where the laser beams 233 and 234 intersect with the trajectory of the droplet 200 are different.
Thereby, since the time difference can be measured, the flight speed of the droplet 200 can be calculated.

  When observing such a droplet 200, the observed droplet 200 is preferably in the vicinity of a point F where the laser beam 233 and the laser beam 234 intersect. At this time, the distance h becomes very small. On the other hand, since the light receiving elements 433 and 434 themselves have a certain size, it is difficult to set the distance H as small as the distance h. However, the distance H can be set large because the laser beam 233 and the laser beam 234 intersect each other as in this embodiment.

  Further, when observing the droplet 200, each time the droplet 200 is observed, the position of the nozzle hole 101 to be observed is detected by the operation of the nozzle hole position detecting means 7 as in this embodiment. The method is not limited to observing the droplet 200 from the nozzle hole 101. For example, by the operation of the nozzle hole position detecting means 7, the position of each nozzle hole 101 to be observed is stored in the storage means 62 of the control means 6 in advance, and based on the information (position), The droplet 200 may be observed.

The plurality of nozzle holes 101 is not limited to all the nozzle holes 101 provided in the droplet discharge head 100, and may be any nozzle hole 101 that discharges the droplet 200 to be observed.
Further, the number of nozzle holes 101 formed in the droplet discharge head 100 is not limited to six as in this embodiment, and may be two to five or seven or more.
Further, the flight state of the droplet 200 that can be observed is not limited to the flight speed as in the present embodiment, and examples thereof include ejection failure, flight bend, and flight direction.

Further, the moving means 3 is not limited to the one using the ball screw 33 as in this embodiment, and may use any structure, for example, a belt such as a timing belt, a rack and pinion gear, a linear An arbitrary configuration using a motor or the like can be used. Further, a linear scale may be installed so as to further improve the positional accuracy of the droplet discharge head 100.
In addition, the moving unit 3 is not limited to moving the droplet discharge head 100 with respect to the laser beam irradiation unit 2 (laser beams 233 and 234) as in the present embodiment. The laser light irradiation means 2 and the light receiving means 4 may be moved.

Further, the number of laser beams 233 and 234 that intersect the trajectory of the droplet 200 is not limited to two as in this embodiment, and may be one or three or more laser beams.
Further, the light receiving means 4 is not limited to being configured by a plurality (two) of light receiving elements 433 and 434 as in the present embodiment, and may be configured by using a CCD camera, for example.
The light receiving elements 433 and 434 are not particularly limited, and examples thereof include a photodiode and a photomultiplier tube.

Second Embodiment
FIG. 7 is a cross-sectional side view of a droplet discharge head provided in the droplet observation apparatus of the present invention.
Hereinafter, the second embodiment of the droplet observation method and the droplet observation apparatus of the present invention will be described. However, the difference from the first embodiment will be mainly described, and the description of the same matters will be omitted.
In the present embodiment, the droplet observation apparatus 1A does not include the nozzle hole position detection unit 7 that detects the position of the nozzle hole 101, and the storage unit 62 of the control unit 6 stores information regarding the position of each nozzle hole 101. Other than the above, the second embodiment is the same as the first embodiment.

Information relating to the position of each nozzle hole 101 is stored in the storage unit 62 in advance. Although this information is not particularly limited, for example, the following information is preferable.
First, the distance between the centers of the nozzle holes 101 of the droplet discharge head 100 (the distances indicated by p ₁ , p ₂ , p ₃ , p ₄ and p ₅ in FIG. 7) is measured (see FIG. 7).
Next, the position of the droplet discharge head 100 is adjusted (moved) so that the trajectory of the droplet 200a discharged from the nozzle hole 101a intersects the laser beams 233 and 234.

Next, this position is stored in the storage means 62 as the position (information) of the nozzle hole 101a (hereinafter, this position is referred to as “position a”).
Next, the position of the droplet discharge head 100 moved by the distance p ₁ from the position a is stored in the storage means 62 as the position (information) of the nozzle hole 101b (hereinafter, this position is referred to as “position b”).

Next, position of the nozzle hole 101c of the droplet discharge head 100 has moved a distance p ₂ from position b (information) as storage means 62 is stored (hereinafter, referred to this position as "position c").
Thereafter, this is repeated sequentially for the nozzle holes 101d, 101e and 101f, and the corresponding positions d, e and f are stored in the storage means 62.

  The control unit 6 of the droplet observation apparatus 1A operates the moving unit 3 based on the information on the position of each nozzle hole 101 stored in the storage unit 62, so that the trajectory of the droplet 200 is changed to the laser beams 233 and 234. The droplet discharge heads 100 are pitch-fed so that the intersecting state is sequentially obtained for the six nozzle holes 101. Meanwhile, the droplet observation means 63 observes the droplet 200 with respect to the nozzle hole 101 where the trajectory of the droplet 200 intersects the laser beams 233 and 234. As a result, the droplets 200 are sequentially observed for the six nozzle holes 101. That is, the control means 6 performs the following control (see FIG. 1).

First, the droplet discharge head 100 moves to position a, and the trajectory of the droplet 200a discharged from the nozzle hole 101a intersects the laser beams 233 and 234.
Next, the light receiving elements 433 and 434 receive the laser beams 233 and 234 that intersect the trajectory of the droplet 200a, respectively.
Next, the droplet observation means 63 is activated, and the flying speed of the droplet 200a is measured based on the output signals of the light receiving elements 433 and 434 that have received the laser beams 233 and 234.

Next, the droplet discharge head 100 moves to position b, and the trajectory of the droplet 200b discharged from the nozzle hole 101b intersects the laser beams 233 and 234.
Next, the light receiving elements 433 and 434 receive the laser beams 233 and 234 that intersect the trajectory of the droplet 200b, respectively.
Next, the droplet observation means 63 is activated, and the flight speed of the droplet 200b is measured based on the output signals of the light receiving elements 433 and 434 that have received the laser beams 233 and 234.

Thereafter, the droplet discharge head 100 is sequentially moved to position c, position d, position e, and position f, and this is repeated for the corresponding droplets 200c, 200d, 200e, and 200f.
Thereby, the effect similar to the above can be acquired.
Note that the information regarding the position of each nozzle hole 101 is not limited to information using the distance between the centers of each nozzle hole 101 as in the present embodiment. For example, the nozzle hole 101b measured from the nozzle hole 101a, Information using the distances to 101c, 101d, 101e, and 101f may be used.

  The droplet observation method and the droplet observation apparatus of the present invention have been described above with reference to the illustrated embodiment. However, the present invention is not limited to this. Each unit constituting the droplet observation apparatus can be replaced with any component that can exhibit the same function. Moreover, arbitrary components may be added.

It is a top view which shows 1st Embodiment of the droplet observation apparatus of this invention. It is a side view which shows 1st Embodiment of the droplet observation apparatus of this invention. It is a side view which shows 1st Embodiment of the droplet observation apparatus of this invention. It is the sectional view on the AA line in FIG. 3, BB sectional drawing, and CC sectional drawing. It is a block diagram showing roughly a 1st embodiment of the principal part of a droplet observation device of the present invention. It is a side view which shows 1st Embodiment of the droplet observation apparatus of this invention. It is a cross-sectional side view of a droplet discharge head provided in the droplet observation apparatus of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 1A ... Droplet observation apparatus 2 ... Laser beam irradiation means 21 ... Laser beam irradiation part 23, 231, 232, 233, 234 ... Laser beam 25 ... Beam splitter 26 ... Laser blade 27 ... Lens 3 ... Moving means 31 ... Guide rail 33 ... Ball screw 34 ... Servo motor 4 ... Light receiving means 433, 434 ... Light receiving element 6 ... Control means 61 ... CPU 62 ... Storage means 63 ... Droplet Observation means 7... Nozzle hole position detecting means 71... Camera 72... Image processing means 100... , 200a, 200b, 200c, 200d, 200e, 200f... Droplet 300. Part 400 ...... flight region 401 ...... passage region

Claims (8)

A droplet observation method for observing a droplet ejected from a plurality of nozzle holes provided in a droplet ejection head and flying,
While irradiating at least one laser beam from the laser beam irradiation unit in a direction crossing the flight direction of the droplet, and detecting the output signal of the light receiving unit that receives the laser beam and performs photoelectric conversion,
By moving the droplet discharge head relative to the laser light irradiation means based on the information on the position of each nozzle hole, the state in which the trajectory of the droplet intersects the laser light is the plurality of nozzle holes. The droplet discharge heads are relatively pitch-fed along the arrangement direction of the plurality of nozzle holes so that the nozzle trajectory of the droplet intersects the laser light. A droplet observing method characterized in that information on ejected droplets is obtained based on an output signal of a light receiving means, whereby droplets are sequentially observed for the plurality of nozzle holes. A droplet observation apparatus for observing a droplet ejected from a plurality of nozzle holes provided in a droplet ejection head and flying,
Laser light irradiation means for irradiating at least one laser light in a direction crossing the flight direction of the droplets;
A light receiving means for receiving the laser beam and performing photoelectric conversion;
Based on the output signal of the light receiving means, a droplet observing means for obtaining information about a droplet ejected from a nozzle hole to be observed;
Moving means for moving the droplet discharge head relative to the laser light irradiation means along the arrangement direction of the plurality of nozzle holes;
Control means for controlling the operation of the moving means;
Nozzle position detecting means for detecting the position of the nozzle hole,
By operating the moving means based on the information regarding the position of each nozzle hole detected by the nozzle hole position detecting means, the state in which the trajectory of the droplet intersects the laser beam is sequentially applied to the plurality of nozzle holes. The droplet discharge head is relatively pitch-fed so as to obtain, during which the droplet observation means observes the droplet in the nozzle hole where the trajectory of the droplet intersects the laser beam, Thus, the droplet observation apparatus is configured to sequentially observe the droplets with respect to the plurality of nozzle holes.   The nozzle hole position detection unit includes a camera that captures an electronic image of a nozzle surface of the droplet discharge head, and an image processing unit that detects the position of the nozzle hole by performing image processing on the electronic image. The droplet observation apparatus according to 2. A droplet observation apparatus for observing a droplet ejected from a plurality of nozzle holes provided in a droplet ejection head and flying,
Laser light irradiation means for irradiating at least one laser light in a direction crossing the flight direction of the droplets;
A light receiving means for receiving the laser beam and performing photoelectric conversion;
Droplet observation means for observing a droplet based on an output signal of the light receiving means;
Moving means for moving the droplet discharge head relative to the laser light irradiation means along the arrangement direction of the plurality of nozzle holes;
Control means for controlling the operation of the moving means;
Storage means for storing information regarding the position of each nozzle hole,
By operating the moving means based on the information on the position of each nozzle hole stored in the storage means, a state in which the trajectory of the droplet intersects the laser light can be obtained sequentially for the plurality of nozzle holes. The droplet discharge head is relatively pitch-fed, and during that time, the droplet observation means observes the droplet with respect to the nozzle hole where the trajectory of the droplet intersects the laser beam, A droplet observation apparatus that sequentially observes droplets from a plurality of nozzle holes.   The laser light irradiation means irradiates a plurality of laser beams, and the plurality of laser beams intersect with the trajectory of the droplet corresponding to the nozzle hole to be observed, respectively. The droplet observation apparatus according to any one of the above.   The droplet observation apparatus according to claim 5, wherein the droplet observation unit obtains information related to a flight speed of the droplet based on a time difference in output signal change of the light receiving unit with respect to the plurality of laser beams.   The droplet observation apparatus according to claim 5 or 6, wherein the plurality of laser beams intersect each other.   The droplet observation apparatus according to claim 7, wherein a position where the plurality of laser beams intersect with each other and a position where the plurality of laser beams intersect with the trajectory of the droplet are different.

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