JP2002370345A - Liquid droplet discharging unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid droplet discharging unit which can prevent a non-intended liquid droplet from being discharged and hence from being adhered to an unnecessary place or from scattering into air, to be used for an ink jet printer or the like in which a discharging direction of an ink droplet is fundamentally in an open space like an electronic stamp and which has a high safety. SOLUTION: The liquid droplet discharging unit comprises a discharge head having a plurality of nozzles for discharging liquid droplets and a plurality of liquid droplet discharge means disposed corresponding to the plurality of nozzles and to be driven to be modulated in response to a signal, a detecting means for detecting a state of a virtual surface opposed to the head or an angle detecting means for detecting an angle between the discharging direction of the droplet from the head and a vertical direction, and a means for inhibiting the discharge of the droplet from at least a part of the plurality of the nozzles in response to the detected result of the detecting means or the detecting angle by the angle detecting means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a droplet discharge device used for an ink jet printer or the like.
More specifically, the present invention relates to a highly safe droplet discharge device that prevents unintended discharge of ink in a handy type inkjet printer or the like.

[0002]

2. Description of the Related Art Various types of printers employ a thermal ink jet system in which a portion of ink is rapidly vaporized by heating with a heater, and ink droplets are ejected from nozzles by the expansion force or the like (Japanese Patent Laid-Open No. 48-48). No. 9622,
No. 54-51837, etc.). Further, there is also known a printer that uses an ink jet that vibrates a vibration plate by a driving unit such as static electricity or a piezo element, and discharges ink droplets from a nozzle by the energy (Japanese Patent Application Laid-Open Nos. 11-207956 and 11-207956). 309850, etc.).

[0003] Such an ink jet printer usually takes an ink receiver, that is, a recording medium (hereinafter, represented by a recording sheet) such as a recording sheet, a recording sheet, an image receiving sheet, or an image receiving medium into the apparatus. , While transporting,
Perform image recording.

For example, a so-called line head type ink jet recording head (hereinafter, referred to as an ink jet recording head) in which nozzles for ejecting ink over one side of a target recording sheet are arranged.
In the case of a printer using a recording head, the recording head is fixed, and while the recording sheet is positioned at a predetermined recording position, the recording sheet is continuously conveyed (scanned) in a direction orthogonal to the nozzle arrangement direction. (Conveyance), an image is recorded on the entire surface of the recording sheet. In the case of a so-called serial type printer, which is widely used, the recording sheet is intermittently conveyed at a predetermined pitch corresponding to the length of the nozzle array, and the nozzle arrangement direction is stopped while the conveyance of the recording sheet is stopped. The image is recorded on the entire surface of the recording sheet by repeatedly performing image recording by scanning the recording head in a direction perpendicular to the direction of the recording sheet.

[0005] On the other hand, there is also known an electronic stamp type ink jet printer which is arranged at a position corresponding to a recording medium and records an image without taking a recording medium such as a recording sheet into the apparatus. For example, JP-A-3-26
No. 1560 discloses a plane in which a recording head (printer) body in which nozzles are arranged in a matrix (two-dimensional) shape is placed on an arbitrary recording sheet and two-dimensional printing (image recording) is performed by inkjet. A printer is disclosed.

In such a printer as an electronic stamp, prior to image recording, the printer is positioned with respect to a recording sheet (recording medium) so that the recording sheet faces the nozzles of the recording head. Then, image recording (droplet ejection) is performed. Therefore, unlike printers that take in a recording sheet and record an image while transporting it, such as the above-mentioned serial type printer, the size, shape, thickness, and stiffness of the recording sheet (strength, hardness, etc.) There is an advantage that image recording can be performed without any restrictions. Further, since the recording target is not taken into the inside of the printer, various objects such as walls and three-dimensional objects can be used as a recording medium in addition to the recording sheet, and an image can be recorded on these recording media. There is also an advantage.

On the other hand, a printer such as an electronic stamp discharges ink at an arbitrary position in accordance with an arrangement position, a situation, a direction, and the like, since an ink discharge direction is an open space. can do. Therefore, for example, when the ink is ejected inadvertently in an unintended situation, such as when the ink is ejected before the recording head properly faces the recording sheet, the ink may be other than the recording object of the image. It adheres to objects, for example, human skin, clothes, furniture, and the like. Even if the ink does not adhere to anything other than the recording target, the situation where the ink is scattered in the air is not preferable because the ink is not toxic but the air becomes dirty.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and the ink ejection direction is basically an open space like the above-mentioned electronic stamp. A droplet discharge device used for an inkjet printer or the like that modulates according to a signal and discharges a droplet, and a droplet discharge head is not properly facing a droplet discharge target. , Which can prevent unintentional ejection of droplets, and thus prevent droplets from adhering to unnecessary places and dispersal of droplets into the air. It is to provide a device.

[0009]

According to a first aspect of the present invention, a plurality of nozzles for discharging liquid droplets and a plurality of nozzles are provided corresponding to each of the plurality of nozzles. An ejection head having a plurality of droplet ejection means that are modulated and driven in accordance with a signal, a detection means for detecting a state of a virtual surface facing the ejection head, and at least a detection result obtained by the detection means. Means for inhibiting droplet discharge from a part of the plurality of nozzles of the discharge head.

In the droplet discharge apparatus according to this aspect, the detecting means may be a human body detecting means or a distance between the discharge head and an object present at a position where the plurality of nozzles of the discharge head discharge droplets. Preferably, the means or the detecting means is a change detecting means for detecting a change in the state of the recording medium present at the droplet discharge positions of the plurality of nozzles of the discharge head.

According to a second aspect of the present invention, there are provided a plurality of nozzles for ejecting liquid droplets, and a plurality of nozzles, each of which is arranged corresponding to each of the plurality of nozzles and which is modulated and driven in accordance with a signal. A discharge head having droplet discharge means, and an angle detection means for detecting an angle between a discharge direction of droplets from at least a part of the plurality of nozzles of the discharge head and a predetermined reference direction, for example, a vertical direction And a means for inhibiting discharge of droplets from at least a part of the plurality of nozzles of the discharge head in accordance with an angle detected by the angle detection unit. It is.

Further, in the droplet discharge devices according to the first and second aspects, it is preferable that the direction of droplet discharge from the discharge head is an open space. Preferably, the droplet is an ink droplet, and the droplet discharge device is an ink jet printer.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a droplet discharge device according to the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

FIG. 1 shows a conceptual diagram of an embodiment of an ink jet printer using the droplet discharge device of the present invention. In FIG. 1, (A) is a side view (described later, as viewed from the nozzle row direction), (B) is a front view (described later, as viewed from the scanning direction), and (C) is a bottom view ( FIG.

An ink jet printer (hereinafter, referred to as a printer) 10 shown in FIG.
, Legs 14, rollers 16, auxiliary wheels 17, and an ink jet recording head (hereinafter, referred to as a recording head) 18.
And an IR (infrared) sensor 20. The printer 10 records an image on a recording medium other than a human (a recording sheet P is illustrated in the illustrated example).
A user (user) contacts the legs of the printer 10 with the ink ejection surface facing the recording medium (recording sheet P), and arranges the nozzles in the recording head 18 in the direction in which the nozzles are arranged (in the direction of arrow a in the figure). By manually moving (scanning) in a predetermined direction (hereinafter, referred to as a scanning direction) indicated by an arrow b in the figure, which is orthogonal to (hereinafter, referred to as a nozzle row direction),
A full-color image is recorded on a recording medium (recording sheet P).

As shown in the block diagram of FIG. 2, the main body 12 has a CPU 30 for controlling the entire printer 10, a driver 32 for the recording head 18, a detection level setting device 36, and an abnormal display. Unit 38, recording instruction switch (SW) 40, data input unit 42, data memory 4
4. Display 46 and forced recording switch (SW) 48
Are arranged inside or outside. These will be described later together with the operation of the printer 10. Note that an ink tank for supplying ink to the recording head 18 is mounted inside the main body 12 (or external mounting is also possible).
Further, the shape of the main body 12 is not limited to a substantially quadrangular prism shape.

The lower surface of the main body 12 (the surface facing the recording sheet P, ie, the surface on which the ink jet recording head 18 is arranged)
Are fixed to the four corners. In the illustrated example of the printer 10, the four legs 14 (or rollers 16 described later instead of the two legs 14) are brought into contact with (for example, placed on) the recording sheet P, thereby forming an ink jet recording head. The distance between the recording sheet 18 and the recording sheet P is properly maintained. In a preferred embodiment, the lower surface of the main body 12 prevents the recording sheet P from floating, and
Auxiliary wheels 17 are provided for keeping the position of the recording sheet P constant at the ink discharge positions from 8 to enable recording of high-quality images. The auxiliary wheel 17
Is basically a roller that rotates in the scanning direction, but it is preferable that a roller that may contact the recording sheet P after image recording (after ink reception) has a small contact area with the recording sheet P, For example, a spur-shaped roller or a roller with a warp is preferably exemplified.

A pair of legs 14 (the right side in the figure in the illustrated example) opposed to the nozzle row direction (in FIG. 1A, the direction perpendicular to the plane of the paper) is a leg 14 A roller 16 that projects slightly in the direction of ink ejection (hereinafter, this direction is referred to as downward) is pivotally supported. That is,
The roller 16 rotates in the scanning direction (in FIG. 1B, the direction perpendicular to the plane of the drawing). Further, a rotary encoder 50 is mounted on the roller 16 (its rotation axis), and the roller 16 is moved by the movement of the printer 10 in the scanning direction.
And generates a pulse signal corresponding to the rotation of the control signal, and sends the pulse signal to the CPU 30 (see FIG. 2).

On the lower surface of the main body 12, an ink jet recording head (hereinafter, referred to as a recording head) 18 is arranged.
In the illustrated example, the recording head 18 is
It is installed so as to eject ink in a direction perpendicular to the lower surface of the main body 12. That is, the ink is ejected toward an open space outside the printer 10.

The recording head 18 is a known (inkjet) recording head having nozzles for discharging ink and ink discharging means corresponding to each nozzle, and has a large number of nozzles in the nozzle row direction (direction of arrow a). It has an array of nozzles. In the illustrated example, the nozzle rows 18Y that discharge Y (yellow) ink and the nozzle row 1 that discharges M (magenta) ink are arranged in the scanning direction (the direction of arrow b).
A nozzle array 18C for discharging 8M, C (cyan) ink,
And a nozzle row 18K for discharging K (black) ink.

The printer 10 is placed on the recording sheet P, and is moved in the scanning direction (the direction of the arrow b) by the user, so that the recording sheet P is two-dimensionally scanned by the nozzle row of the recording head 18. The CPU 30 detects the moving amount (scanning amount) of the printer 10 based on the pulse signal generated by the rotary encoder 50 at this time, adjusts the ink ejection timing in synchronization with the movement, and modulates the ink according to the recording image. Then, the recording head 18 is driven by the driver 32, and the recording head 18 modulates and discharges the ink of each color, so that the recording sheet P
, Full color images of Y, M, C and K are recorded. As will be described later, in the illustrated example, the rotary encoder 5 is used.
In response to the pulse signal generated at 0, the IR sensor 20 measures IR light. In the printer 10, this makes it possible to compensate for fluctuations in the moving speed of the printer 10 by the user, to enable proper image recording, and
As a result, erroneous ejection of ink is reliably prevented.

Here, the printer 10 in the illustrated example records an image by being moved in the direction of arrow b. However, the present invention is not limited to this. It may be recorded.

In the printer 10 of the present invention, as described above, the recording head 18 may be a known ink jet recording head. Therefore, the recording head 18 may be of a so-called top shooter type (face inkjet) that discharges ink in a direction perpendicular to the substrate, or a so-called side shooter type (edge inkjet) that discharges ink in parallel to the substrate. It may be. Also, a so-called thermal ink jet, which discharges ink by heating by a heater, may be used. A recording head that vibrates a vibration plate of an ink chamber using a piezo element or electrostatic force and discharges ink with this force. May be. Furthermore, in addition to the above four colors, an ink column such as light C or light M may be used, or a monochrome printer that ejects only K ink instead of a color printer may be used.

On the lower surface of the main body 12, an IR sensor 20 is arranged. In addition, in order to ensure higher security, the IR sensor 20 is preferably arranged near the recording head 18. In the illustrated printer 10, I
The R sensor 20 is a detection unit that detects the state of the virtual surface facing the recording head (ejection head) 18, specifically, the state of the ejection position of ink (droplets) from the recording head 18. In the present invention, the ink ejection position is defined as
A region where the recording head 18 discharges ink, including the ink discharge surface (for example, the surface of the orifice plate (the surface on the ink discharge side) where the nozzles are formed in the recording head 18). Note that a recording surface such as the surface of a recording medium may be used as the virtual surface or the ink ejection position.

FIG. 1 illustrates the recording sheet P as a recording medium (ink receptor).
Is for recording an image by ejecting ink using a medium other than a person as a recording medium, and ejecting ink when a human body is present at the ink ejection position (a human body is facing the recording head 18). do not do. (Ink ejection (image recording) is not started. Ink ejection is prohibited or stopped during recording.) In the printer 10, the IR sensor 20 detects the intensity of IR from the ink ejection direction, thereby detecting the ink ejection. It is detected whether or not a human body is present at the ejection position, and if a human body is detected, the recording head 18 does not eject ink.

In the present invention, by providing a detecting means for detecting the state of the ink discharge position, various types of recording sheets such as image receiving paper and recording paper can be used without limitation on the thickness and strength of the paper. Three-dimensional objects such as plate materials,
The ink ejection direction is basically open, such as a printer that uses various image receiving media such as walls as a recording medium, or a printer that moves to an arbitrary location and records an image, such as the aforementioned electronic stamp. Space (inkjet)
In the printer, careless ejection of ink can be prevented,
Improper position as a recording medium such as human skin or clothes,
A safe printer (droplet ejection device) that prevents ejection / spraying of ink into the air in a room or the like can be realized.

In the present invention, the IR sensor 20 used
There is no particular limitation, and for example, various known devices used for detecting a human body by IR, such as a thermopile using a thermoelectromotive force and a pyroelectric sensor using a pyroelectric effect, can be used. The human body detection is not limited to the method using IR, and various methods can be used. For example, a method of detecting carbon dioxide using a metal oxide sensor, a method of irradiating light in the ink ejection direction and measuring the amount of reflected light, and the like, determine whether or not a human body exists in the ink ejection direction. May be detected.

In the present invention, the detecting means for detecting the state of the ink discharge position is not limited to the human body detecting means. For example, the position of the recording medium existing at the ink discharge position from the printer, in other words, The relative positional relationship between the printer and the recording medium may be detected, and the ejection of the ink may be prohibited or stopped according to the result.

As a preferred example, a contact sensor with a recording medium, a microswitch that is turned on (or off) in contact with an object, or the like is attached to the leg 14 or the main body 12 as a detecting means. When the contact sensor is not in contact with the recording medium or when the micro switch is not properly turned on, a method of prohibiting or stopping the ejection of ink is exemplified. In this embodiment, two, preferably three or more contact sensors are arranged at distant positions,
If all of the contact sensors and the like are not in the proper state, it is preferable to determine that they are inappropriate. In addition, when the detection unit comes into contact with the recording medium, it is preferable that the detection unit is disposed at a position that does not come into contact with the recording medium immediately after ink ejection.

A distance measuring means is used as a detecting means, and a distance between the recording head 18 (for example, an ink ejection surface) and a recording medium is measured. How to prohibit or stop dispensing,
It is suitable. At this time, the appropriate distance is not particularly limited, and may be appropriately set according to the characteristics of the recording head. The method for measuring the distance is not particularly limited. For example, a known means such as an optical distance sensor using the principle of triangulation or an acoustic distance sensor may be used.

As shown in FIG. 6, when the interior 90 of a building is printed as a recording medium, an area 92 to be recorded, such as a wall to be ejected, and a portion not to be ejected, for example, a window, a window frame, an outlet, and an air intake. By discriminating the recording prohibited area 94 such as a mouth, a skirting board, and other attachments, the prohibition of discharge from at least a part of the discharge head 96, that is, the discharge from a part or all of the nozzles of the droplet discharge head 96. It is necessary to control ejection prohibition. In FIG. 6, reference numeral 92a denotes a recorded area in the area 92 to be recorded, and reference numeral 92b denotes an unrecorded area in the area 92 to be recorded. In this case, as shown in FIG. 6, it is generally considered that the area 92 to be recorded and the recording prohibited area 94 are designated in advance by coordinates or the like, but this method not only requires the accuracy of the recording apparatus but also In addition, it is necessary to accurately obtain the positional accuracy between the recording apparatus and the recording medium, for example, a building, which not only makes the apparatus expensive, but also has extremely poor workability and requires a long time to start recording. .

To solve this problem, in the present invention,
The change of the state of the recording medium is detected by the detecting means, and the ejection is controlled (whether or not to perform recording) based on this state, so that recording is performed only on necessary portions, for example, as shown in FIG. Can be performed. The means for detecting the state of the recording medium includes the above-described IR sensor 20, the distance measuring means, the relative position detecting means such as the contact sensor, and the like. For example, optics (reflectance, color, IR, etc.) , Surface roughness, (ultra) sonic waves, temperature, and the like.

Further, it is more preferable to change the threshold value in accordance with the use condition when the ejection prohibition is determined by such a detecting means. For example, when recording in a room 90 of a building as shown in FIG.
The state of the recording medium in the area 92 to be printed and the state of the recording medium in the recording prohibited area 94 where printing should be prohibited are scanned in advance by a droplet discharging apparatus on the surface to be printed without discharging ink. It is preferable that the state of the recording medium is measured by the recording medium state detecting means provided in the above-mentioned method, and a threshold value for prohibiting ejection is determined based on the measurement result. Also, the ejection prohibition area determined based on the threshold value may be confirmed on a CRT monitor or the like, and the recording prohibition data may be partially added, or the ejection prohibition data may be partially deleted. good. Further, the state of the recording medium may be monitored while recording, and recording / recording inhibition may be determined based on a preset threshold value. Further, it is more preferable that the detecting means can detect a plurality of areas so as to be able to determine according to the position in the head (nozzle row). For example, when approaching the boundary of the window frame from the wall, ejection prohibition control is performed for the nozzle at the front end in the head traveling direction, but it is preferable that the center and the rear end still continue ejection.

In the various examples described above, the state of the recording medium facing the ejection head is detected by the detecting means, and the ejection of ink is inhibited according to the result. However, the present invention is not limited to this. Instead, the state of the ejection head itself may be detected, and the ejection of ink may be prohibited according to the result.
As a detecting means for detecting the state of the ejection head itself, for example, a detecting means for detecting the direction of droplet ejection from the ejection head can be mentioned. As such a means for detecting the direction of droplet ejection from the ejection head, an angle detecting means can be mentioned, and for example, an angle detecting means for measuring an angle formed by a weight attached to the head main body with a vertical direction. A method of detecting the angle between the ink ejection direction and the vertical direction, and prohibiting or stopping the ink ejection when the angle is inappropriate is also preferably exemplified. For example, mainly for a printer that records an image on a recording medium placed on a desk or the like, the ink ejection direction is usually substantially the same as the vertical direction, and the ink ejection direction and the vertical direction are generally the same. Is too large, the ejection of ink is prohibited or stopped. On the other hand, mainly in the case of a printer that records an image on a wall surface or a screen, since the ink ejection direction is substantially horizontal, the angle between the ink ejection direction and the vertical direction is about 90 °. When the angle deviates from 90 ° by a predetermined amount or more, the ejection of the ink is prohibited or stopped.

In this embodiment, the angle between the vertical direction and the ink ejection direction is not particularly limited, and may be appropriately determined according to a recording medium mainly targeted by the printer or a state where the printer is normally used. Good. A known angle detection unit may be used. Although there is no particular limitation on the allowable angle range, in order to ensure sufficient security, it is preferable to set the angle to about ± 5 ° based on an ideal angle for recording. In the above-described example, the angle of the ink ejection direction is obtained based on the vertical direction. However, the present invention is not limited to this, and a reference direction is set in advance as a reference, and the preset reference direction is set. The angle of the ink ejection direction with respect to the direction may be obtained. For example, by setting this reference direction to the original (or correct) ink ejection direction, the angle between this reference direction and the actual ink ejection direction can be calculated as follows.
It can be set as a deviation angle from the reference direction.
Therefore, in the case where the ink is ejected in the above-described vertical direction and an image is recorded on a recording medium placed on a desk or the like, the ink is also ejected in a horizontal direction that forms 90 ° with the vertical direction, Recording an image on a wall surface, a partition, or the like can be handled in the same manner, and the allowable angle range can be set on the same basis, which is preferable.

In the present invention, it goes without saying that a plurality of detecting means for detecting the state of the ink discharge position may be used in combination.

Hereinafter, the present invention will be described in more detail by describing the operation of the printer 10 with reference to FIG. When the power of the printer 10 is turned on, various displays (for example, whether or not printing is possible, the presence or absence of image data, etc.) are displayed on the display 46, and the CPU 30 resets the ejection prohibition flag (Flag). Then, the abnormality display of the abnormality indicator 38 is turned off. If necessary, the user may be allowed to select a recorded image, input the number of prints, and the like. These are provided by a GUI (Graphica
l UserInterface) or another known method.

Next, it is confirmed whether image data exists in the data memory 44 and whether or not the image data is image data corresponding to recording. If image data corresponding to recording is not stored, data input is performed. The image data is fetched from the unit 42 into the data memory 44. The capture of the image data may be performed by a known method such as a wired or wireless download or a read from a loaded recording medium. The supply source of the image data may be the same as various printers such as a scanner (image reading device), a computer, a digital camera, and a communication network. Further, in addition to the supplied image data, image data of a predetermined pattern may be stored, and an image may be recorded with the image data of this pattern in accordance with an instruction.

If image data corresponding to recording exists in the data memory 44 and the recording instruction switch 40 is turned on, then IR measurement from the ink ejection position is performed by the IR sensor 20. Alternatively, the IR sensor 20 constantly performs measurement, and outputs the output to the CPU 3.
0 may be confirmed. The recording instruction switch 40 is
The user may turn on / off, or the printer 1
It may be turned on / off automatically according to the state of 0, for example, whether recording is possible or not.

The timing of measurement by the IR sensor 20 is not particularly limited. However, as a preferred embodiment, every time the printer 10 is moved by a predetermined amount in the scanning direction (the direction of arrow b) by the user, Each time the 50 generates a predetermined number of pulse signals, the measurement by the IR sensor 20 is performed. Alternatively, it is also preferable to perform the measurement by the IR sensor 20 at a predetermined time interval or at a predetermined number of clocks.

The measurement result (output signal) by the IR sensor 20 is converted into a digital signal by the A / D converter 34 and sent to the CPU 30. The CPU 30 confirms the measurement result, and when the measured IR is equal to or smaller than the set value (threshold), the CPU 30 moves the printer 10 by the user, that is, generates a pulse signal from the rotary encoder 50, and The driver 32 is driven by modulating according to the recording image, and the recording head 18 ejects the ink modulated according to the recording image for a predetermined time (a predetermined number of lines).

Incidentally, the IR measurement timing and the ink ejection time may be appropriately set according to the required safety and the like. Further, in the illustrated example, as a preferable mode, the intensity of the IR for determining that a human body is present (the set value) can be arbitrarily set by the detection level setter 36. However, the present invention is not limited to this, and a fixed value may be set according to the target safety or the like.

If the image data to be recorded remains in the data memory 44 after the ink modulated according to the image is ejected for a certain period of time, as long as the value measured by the IR sensor 20 does not exceed the set value, the "IR Measurement by Sensor 20 "~
"Ink ejection" is repeated. When the ink ejection for all the image data of this image is completed, the recording of this image is completed, and it is confirmed whether or not the image data to be recorded next exists in the data memory 44, and the image data exists. If a recording instruction has been issued, image recording is performed in the same manner. Image recording is performed in response to a compulsory recording switch on which will be described later (compulsory recording). When recording of one image is completed, the abnormal display is turned off, the data memory 44 is checked, and similarly, Perform image recording. The image data for which recording has been completed is deleted from the data memory 44 automatically or in response to an instruction from the user. It is preferable that such erasure of image data be selectable.

On the other hand, when the measured value of IR by the IR sensor 20 exceeds the set value, the CPU 30 determines that there is a person in the ink ejection direction, and turns on the abnormality display by the abnormality display 38.

The CPU 30 turns on the abnormal display, or further warns with an alarm, etc.
Check 8. When the forcible recording switch 48 is turned on, the image is forcibly recorded by ejecting the ink for a certain period of time in the same manner as described above regardless of the abnormality detection.

When the forced recording switch is off, C
The PU 30 forcibly turns off the recording instruction switch 40, does not perform image recording (does not start ink ejection, and inhibits or stops ink ejection during recording), and includes recorded image data. And image data in the data memory 44
To hold. Next, a recording prohibition flag is set, a warning is generated by an alarm, and this image recording is forcibly terminated. At this time, the image recording may be resumed after some instruction input (for example, the recording instruction switch 40 is turned on) by the user.
Alternatively, when the image recording is forcibly terminated, the power of the printer 10 may be automatically turned off, and the image recording may be restarted after the user turns on the power again.

FIG. 4 shows a conceptual diagram of another embodiment of the ink jet printer according to the present invention. 4A is a plan view (top view) and FIG. 4B is a side view.
The above-described printer 10 performs image recording by manually moving the printer 10 in a predetermined scanning direction by a user. The inkjet printer 60 (hereinafter, referred to as a printer 60) illustrated in FIG. Recording medium M
After being installed at a location corresponding to (or its image recording position), image recording is performed by moving the (inkjet) recording head two-dimensionally like an xy plotter.

The printer 60 shown in FIG. 4 extends in one direction (in FIG. 4B, a direction perpendicular to the plane of the drawing, hereinafter referred to as an x direction), and is provided with two bases arranged in parallel at an interval. In the vicinity of the base 62 and the end of the base 62 in the extending direction,
two first guide arms 66 extending in a direction orthogonal to the x direction (hereinafter, referred to as the y direction) and fixed so as to be bridged by both bases 62; A slider 68 held by a guide arm 66 and a second guide arm 6 extending in the x-direction and supported by both sliders 68
9 and a head unit 70 supported by a second guide arm 69 movably in the x direction.

Although not shown, a recording head is arranged on the lower surface of the head unit 70. The recording head is arranged so as to eject ink in a direction perpendicular to the plane formed by the rectangular frame formed by the base 62 and the guide arm 66 (that is, the ink is released from the outside of the printer 60 in an open state). Is discharged into an appropriate space). The recording head is a publicly known one similarly to the example shown in FIG. 1, and in the illustrated example, as an example, C,
It has four nozzle rows of M, Y and K.

Further, the head unit 70 is provided with a distance sensor 72 as a detecting means for measuring the distance to an object located below (ink ejection position). The distance sensor 72 described above may be used. As the detecting means, all the above-described examples such as an IR sensor and a contact sensor can be used other than the distance sensor. These detecting means are provided on the base 62 or the guide arm 66 according to the detecting method or the like.
It goes without saying that they may be arranged at the same position.

The base 62 has a known wire driving means using a wire 74, and the slider 68 movably held by the guide arm 66 is moved in the y direction by the wire driving means. The slider 68 also has a well-known wire driving unit using a wire 76, and the head driving unit movably held by the second guide arm 69 is moved in the x direction by the wire driving unit. That is, the head unit 70 having the recording head on the lower surface is two-dimensionally moved over the recording medium M by the two wire driving units.

Therefore, in the printer 60, according to the above-described serial type (inkjet) printer, after the head unit 70 is moved in the x direction to perform image recording by ink jet, the length of the nozzle array is adjusted. By repeatedly moving the slider 68 (head unit 70) in the direction of arrow y by a predetermined amount and moving the head unit 70 in the direction x again to record an image, the image is recorded on the recording medium M two-dimensionally. Can be recorded.

Here, in the printer 60, basically, the object facing the recording head (ink ejection surface) and the ink ejection surface of the recording head (head unit 70) are determined according to the measurement result by the distance sensor 72. When the distance to the image is within a predetermined range, image recording is performed by discharging ink.
On the other hand, if the distance is out of the predetermined range, the ink is not ejected because the ink ejection is inappropriate (if the recording is being performed, the ink ejection is prohibited or stopped). Alternatively, the position of the recording head may be configured to be adjustable in the ink ejection direction, and the ejection of the ink may be prohibited or stopped when the position exceeds the adjustment range measured by the distance sensor 72. The sequence at this time may be in accordance with, for example, the above-described flowchart of FIG.

Therefore, also in this embodiment, only when the recording medium M is properly present at the ink ejection position,
Since the ink is ejected (image recording), it is possible to prevent the ink from being scattered to a person, a space, or the like.
0 can be realized.

Although the (inkjet) printer of the present invention described above records an image on a plane, the present invention is not limited to this, and a plurality of three-dimensional objects can be used. The image recording may be performed simultaneously on the surface. For example, FIG. 5 ((A) is a side view, (B)
(Front view)) (inkjet) printer 80 shown in FIG.
As described above, a rectangular frame body 82 is used, and the recording heads 84 are arranged on two inner side surfaces and a ceiling surface of the frame body 82 facing each other. The recording head 84 has a nozzle row extending in a direction orthogonal to a scanning direction indicated by an arrow b in the drawing (in FIG. 5B, a direction orthogonal to the paper surface), and has an inner wall surface of the frame 82. Are arranged so as to eject ink in a direction perpendicular to the direction. Therefore, also in the printer 80, ink is ejected into an open space corresponding to the size of the frame 82.

In such a printer 80, the frame 8
2, the recording medium M having a rectangular cross section is inserted, and the frame body 82 and the recording medium M are relatively moved in the scanning direction, and in synchronization with this movement, according to the image to be recorded. The modulated ink is ejected from each recording head 84. Thus, images can be recorded on the three surfaces of the recording medium M by the inkjet. This relative movement (scanning) may move the frame, or may move the recording medium M.

In this printer 80 as well, for example, a detecting means for detecting the state of the above-described ink discharge position is arranged on, for example, the ceiling surface of the frame body 82, and the state of the ink discharge position is not a predetermined state. , The ejection of ink is prohibited or stopped. Thereby, for example, when a recording medium other than the proper recording medium is inserted into the frame 82, or when the recording medium is not present in the frame 82, careless ejection of ink is prevented. Highly secure printer 8
0 can be realized.

Although the above-described example is an example in which the droplet discharge device of the present invention is used in an ink jet printer, the present invention is not limited to this. If it has a droplet discharge means,
It can be used for various droplet discharge devices. For example, the present invention can be suitably used for an apparatus that applies an adhesive in a minute pattern.

Although the droplet discharge device of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various improvements and changes can be made without departing from the spirit of the present invention. Of course, you can.

For example, in the printer 10 shown in FIG. 1 and FIG. 2, the user manually moves the printer 10. It may be a mobile printer. Also,
In the printer 60 of the embodiment shown in FIG. 4, for example, a so-called line head having a long nozzle row extending in the x direction is used, and the image is recorded on the recording medium only by moving the line head in the y direction. May be performed.

[0061]

As described in detail above, the droplet discharge device of the present invention detects the state of the droplet discharge position of ink or the like, and discharges droplets appropriately according to the detection result. If not, the ejection of the droplet is prohibited or stopped. Therefore, according to the droplet discharge device of the present invention, it is possible to realize a highly safe ink jet printer, an adhesive application device, and the like that prevent unnecessary droplets from being discharged into an unnecessary place such as a person or the air.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an example of an ink jet printer according to the present invention, wherein (A) shows a side view, (B) shows a front view, and (C) shows a bottom view.

FIG. 2 is a block diagram of the ink jet printer shown in FIG.

FIG. 3 is a flowchart illustrating an operation of the ink jet printer shown in FIG. 1;

4A and 4B are conceptual views of another example of the ink jet printer according to the present invention, wherein FIG. 4A is a plan view and FIG. 4B is a side view.

5A and 5B are conceptual views of another example of the ink jet printer according to the present invention, wherein FIG. 5A is a side view and FIG. 5B is a front view.

FIG. 6 is an explanatory diagram for explaining the operation of the ink jet printer according to the present invention.

[Explanation of symbols]

 10, 60, 80 (inkjet) printer 12 main body 14 legs 16 roller 17 auxiliary wheel 18 recording head 20 IR sensor 30 CPU 32 driver 34 A / D converter 36 detection level setting device 38 abnormality display device 40 recording instruction switch 42 data input Unit 44 data memory 46 display 48 compulsory recording switch 50 rotary encoder 62 base 66 guide arm 68 slider 70 head unit 72 distance sensor 74, 76 wire 82 frame 84 recording head 90 interior of building 92 area to be recorded 92a recorded Area 92b Unrecorded area 94 Recording prohibited area 96 Droplet discharge head P Recording sheet M Recording medium

Claims (7)

[Claims] An ejection head having a plurality of nozzles for ejecting droplets, and a plurality of droplet ejection means, each of which is arranged corresponding to each of the plurality of nozzles and driven by modulation in accordance with a signal; Detecting means for detecting a state of a virtual surface facing the discharge head; and means for prohibiting discharge of droplets from at least a part of the plurality of nozzles of the discharge head according to a detection result by the detection means. A droplet discharge device comprising: 2. A droplet discharging apparatus according to claim 1, wherein said detecting means is a human body detecting means. 3. The droplet discharging device according to claim 1, wherein the detecting unit is a measuring unit for measuring a distance between an object existing at a droplet discharging position of the plurality of nozzles of the discharging head and the discharging head. apparatus. 4. The change detecting means according to claim 1, wherein said detecting means is a change detecting means for detecting a change in a state of a recording medium present at a position at which the plurality of nozzles of the discharge head discharge droplets. The droplet discharge device according to the above. 5. An ejection head, comprising: a plurality of nozzles for ejecting liquid droplets; and a plurality of droplet ejection means, each of which is arranged corresponding to each of the plurality of nozzles and driven by modulation in accordance with a signal. An angle detection unit that detects an angle between a discharge direction of droplets from at least a part of the plurality of nozzles of the discharge head and a preset reference direction; and, in accordance with a detection angle of the angle detection unit, Means for inhibiting discharge of droplets from at least some of the plurality of nozzles of the discharge head. 6. The droplet discharge device according to claim 1, wherein a direction in which the droplet is discharged from the discharge head is an open space. 7. The ink jet printer according to claim 1, wherein said droplet is an ink droplet, and said droplet discharge device is an ink jet printer.
7. The droplet discharge device according to any one of 6.