JP4415638B2 - Droplet ejection apparatus and droplet ejection method - Google Patents

Description

The present invention, a droplet discharge device, relates to a droplet discharge how.

For example, in a liquid crystal device, liquid crystal disposed in a liquid crystal panel is used as part of display control means.
Conventionally, when placing liquid crystal in such a liquid crystal panel, first the two substrates are bonded together to form the liquid crystal panel, then the inside of the liquid crystal panel is evacuated, and then the liquid crystal is sucked into the liquid crystal panel It is
However, this method has a problem that the amount of liquid crystal used is enormous and the time for manufacturing one liquid crystal panel becomes long.
Therefore, in recent years, there has been disclosed a technique in which a liquid crystal is applied and disposed on a substrate before the two substrates are bonded together by using an ink jet apparatus or the like (see, for example, Patent Documents 1 to 3). In this technique, the liquid crystal, which is a high-viscosity material, is discharged after its viscosity is lowered by heating the liquid crystal to a dischargeable temperature so that the liquid crystal can be discharged by an ink jet apparatus or the like. According to this ink jet type apparatus, the amount of liquid crystal used is small, and the liquid crystal can be arranged with higher definition.
JP-A-5-281562 Japanese Patent Laid-Open No. 10-221666 Japanese Patent Laid-Open No. 2001-183684

  By the way, a heater is used to heat the liquid crystal to a dischargeable temperature and reduce the viscosity. However, the heater takes a long time to heat the liquid crystal. For this reason, it is desired to shorten the heating time of the liquid crystal and improve productivity.

It is an object of the present invention to provide a droplet discharge device and a droplet discharge method that can rapidly heat a liquid material such as liquid crystal to have an appropriate viscosity and can greatly improve the productivity of the liquid crystal device. Yes.

  In order to achieve the above object, a droplet discharge device according to the present invention is a droplet discharge device that discharges a liquid material from a discharge head including a piezoelectric element by vibration of the piezoelectric element, and the piezoelectric element includes: By applying a voltage of a predetermined frequency, the liquid is heated to slightly vibrate to such an extent that the liquid is not discharged, thereby heating the liquid. Note that control means for applying a voltage of a predetermined frequency to the piezoelectric element to slightly vibrate the piezoelectric element may be provided.

  In this way, by applying a voltage of a predetermined frequency to the piezoelectric element and causing the liquid to vibrate to such an extent that it does not discharge, the piezoelectric element generates heat, rapidly heating the liquid in the discharge head, and the viscosity of the liquid Can be made into a state in which good discharge is possible. As a result, the liquid material can be discharged quickly.

  In addition, it is desirable that the control means continuously applies the voltage of the predetermined frequency to the piezoelectric element during the discharging step of discharging the liquid material to slightly vibrate the piezoelectric element. According to this configuration, the liquid material of the discharge head is always heated to an appropriate temperature, and a good discharge by the discharge head can be achieved.

  Further, immediately after the liquid material is discharged, the control means adjusts the voltage value, frequency, or waveform of the voltage applied to the piezoelectric element to slightly vibrate the piezoelectric element, thereby generating a calorific value of the piezoelectric element. It is desirable to increase the value. According to this configuration, when the temperature of the liquid material of the discharge head decreases immediately after the liquid material is discharged, the amount of heat generated by the piezoelectric element is increased, and a good discharge can be quickly achieved.

  Further, the control means adjusts any one of a voltage value, a frequency, and a waveform of a voltage applied to the piezoelectric element to slightly vibrate the piezoelectric element based on a temperature difference between the liquid material of the ejection head and the outside air. It is desirable to do. According to this configuration, it is possible to suppress the influence of the outside air temperature on the viscosity of the liquid as much as possible, and it is possible to obtain a state in which satisfactory discharge can always be performed.

  Further, the discharge head includes a heater for heating the liquid material, and the control means supplies the current to the heater and the piezoelectric element so that the total amount of heat generated by the heater and the piezoelectric element becomes a predetermined value. It is desirable to control the voltage. According to this configuration, since the liquid material is heated together with the heater, the liquid material of the discharge head can be heated more rapidly, and the viscosity of the liquid material can be brought into a state in which favorable discharge is possible.

  Next, a liquid droplet ejection method according to the present invention is a liquid droplet ejection method in which a liquid material is ejected by vibration of the piezoelectric element from an ejection head having a piezoelectric element, and a voltage having a predetermined frequency is applied to the piezoelectric element. Then, the piezoelectric element is caused to generate heat by being vibrated to such an extent that the liquid does not discharge, thereby heating the liquid.

  In this way, by applying a voltage of a predetermined frequency to the piezoelectric element and causing it to vibrate slightly to the extent that the liquid material is not discharged, the piezoelectric element is heated to rapidly heat the liquid material of the discharge head, and the viscosity of the liquid material is increased. It is possible to achieve a state in which good discharge is possible. As a result, the liquid material can be discharged quickly.

  Note that, during the discharge process of discharging the liquid material, the voltage of the predetermined frequency may be continuously applied to the piezoelectric element to cause slight vibration. As a result, the liquid material of the discharge head is always heated to an appropriate temperature, so that the discharge head can perform good discharge.

  In addition, immediately after the liquid material is discharged, the voltage value, frequency, or waveform of the voltage applied to the piezoelectric element may be adjusted to slightly vibrate the piezoelectric element to increase the amount of heat generated by the piezoelectric element. desirable. In this way, when the temperature of the liquid material of the discharge head decreases immediately after the discharge of the liquid material, the amount of heat generated by the piezoelectric element is increased, and a good discharge can be quickly achieved.

  Further, it is desirable to adjust any one of a voltage value, a frequency, and a waveform of a voltage applied to the piezoelectric element so as to cause the piezoelectric element to vibrate based on a temperature difference between the liquid material of the ejection head and the outside air. According to this configuration, it is possible to suppress the influence of the outside air temperature on the viscosity of the liquid as much as possible, and it is possible to obtain a state in which satisfactory discharge can always be performed.

  In addition, it is preferable that a heater is provided in the ejection head, and the current to the heater and the voltage to the piezoelectric element are controlled so that the total amount of heat generated by the heater and the piezoelectric element is a predetermined value. According to this configuration, since the liquid material is heated together with the heater, the liquid material of the discharge head can be heated more rapidly, and the viscosity of the liquid material can be brought into a state in which favorable discharge is possible.

  The liquid crystal device according to the present invention is a liquid crystal device in which a liquid crystal layer is sandwiched between a pair of substrates, and the liquid crystal is formed on one of the pair of substrates by the above-described droplet discharge method. It is characterized by being discharged and applied. As a result, the liquid crystal is quickly discharged onto the substrate and applied to increase the production efficiency, so that the cost can be reduced.

  In addition, an electronic apparatus according to the present invention includes the liquid crystal device. According to this configuration, an electronic apparatus including a low-cost liquid crystal device can be provided.

  The best mode for carrying out a droplet discharge apparatus and a droplet discharge method according to the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

[Liquid Crystal Device]
FIG. 1 shows a plan view of the liquid crystal device with the color filter substrate removed. FIG. 2 is a side sectional view of the liquid crystal device taken along the line HH ′ of FIG. FIG. 1 is a plan view showing a state in which the color filter substrate is removed to explain the planar structure of the TFT array substrate. FIG. 2 is a side sectional view of the entire liquid crystal device including the color filter substrate. Yes.
In the liquid crystal device 200, a liquid crystal 250 is sealed in a space formed by the TFT array substrate 210, the color filter substrate 220, and a sealing material 252 to form a plurality of pixels.

  A TFT array substrate 210 shown in FIG. 1 is obtained by forming a thin film transistor (TFT) as a switching element of each pixel on the surface of a substrate such as glass. A plurality of scanning lines (not shown) extend in parallel from the gate electrode of each TFT (not shown). An interlayer insulating film is formed above each TFT, and a plurality of data lines (not shown) are formed in parallel on the surface. The source of each TFT is connected to each data line through a through hole. Each scanning line and each data line are arranged in a lattice pattern orthogonal to each other, each scanning line is connected to the scanning line driving circuit 204 formed on the peripheral edge of the substrate, and each data line is formed on the peripheral edge of the substrate. The data line driving circuit 201 is connected. Further, terminals 202 for connecting the scanning line driving circuit 204 and the data line driving circuit 201 to the outside are formed on the peripheral edge of the substrate. Further, an interlayer insulating film is formed above the data line, and a pixel electrode (not shown) is formed on the surface thereof. The drain of each TFT is connected to the pixel electrode through a through hole. In addition, an alignment film of liquid crystal molecules is formed above the pixel electrode.

  On the other hand, the color filter substrate 220 shown in FIG. 2 is obtained by forming color filter layers 223 for each color of RGB on the surface of a substrate such as glass. A black matrix is formed in a frame shape in the gaps between the color filter layers 223. A protective film is formed on the surface of the color filter layer, and a common electrode 221 made of ITO or the like is formed on the surface. Further, an alignment film is formed above the common electrode 221. The alignment film formed on the inner surface side of the TFT array substrate 210 and the color filter substrate 220 is composed of a polyimide thin film or the like. In addition, rubbing treatment is performed by rubbing the surface of the alignment film in a predetermined direction with a nylon roll or the like. By this rubbing treatment, the liquid crystal molecules can be regulated in the predetermined direction. Instead of rubbing treatment, it is also possible to regulate the alignment of liquid crystal molecules by forming a plurality of elongated protrusions on the surface of the alignment film. Further, the alignment regulating direction of the alignment film in the TFT array substrate 210 and the alignment regulating direction of the alignment film in the color filter substrate 220 are in a state of being shifted by a predetermined angle.

  As shown in FIG. 1, a sealing material 252 made of a thermosetting resin before curing is applied to the periphery of the image display area of the TFT array substrate 210. The sealing material 252 is formed on the entire circumference of the TFT array substrate 210, and a conductive member 206 for drawing the common electrode of the color filter substrate to the TFT array substrate 210 is formed at the corner. As shown in FIG. 2, a liquid crystal 250 is applied to the inside of the sealing material 252 by an application method described later. The TFT array substrate 210 and the color filter substrate 220 are bonded to each other through the sealing material 252. Thus, the liquid crystal 250 is sealed in a space formed by the TFT array substrate 210 and the color filter substrate 220 and the sealing material 252. Further, a polarizing film (not shown) is formed on the outer surfaces of the TFT array substrate 210 and the color filter substrate 220. The liquid crystal device 200 is configured as described above. A plurality of pixels are formed in a matrix in the image display area of the liquid crystal device 200.

[Droplet discharge device]
FIG. 3 shows a schematic external perspective view of the droplet discharge device. The liquid crystal 250 is applied to the TFT array substrate described above using the droplet discharge device 10 shown in FIG. The droplet discharge device 10 mainly includes a discharge head 20 composed of an inkjet head that discharges a liquid crystal 250 and a head moving unit 16, and a stage 46 and a stage moving unit on which a TFT array substrate (hereinafter simply referred to as a substrate) 210 is placed. 14 and vibration applying means 70 that vibrates the stage 46.

  The head moving means 16 is composed of two support columns 16a and 16a that are erected at a predetermined interval, and a column 16b that is installed on the upper ends of both support columns. A guide rail (not shown) extending in the X direction in FIG. 3 and a slider (not shown) movable along the guide rail are provided on the lower surface of the column 16b. As the slider driving means described above, for example, a linear motor or the like is employed. Thereby, the discharge head 20 arranged below the slider can be moved along the X direction, and can be stopped at an arbitrary position. On the other hand, a linear motor 62 or the like is fixed to the surface of the slider described above, and a rod (not shown) can be moved in the Z direction in FIG. And the discharge head 20 is being fixed to the front-end | tip of the rod. Thereby, the discharge head 20 can be moved along the Z direction, and can be stopped at an arbitrary position. Furthermore, by connecting the ejection head 20 to another motor or the like, the ejection head 20 can be rotated around the X, Y, and Z axes, and can be stopped at any position.

  Here, a structural example of the ejection head 20 will be described with reference to FIG. A reservoir 95 and a plurality of liquid crystal chambers 93 are formed in the head main body 90 of the ejection head 20. The reservoir 95 is a flow path for supplying the liquid crystal 250 to each liquid crystal chamber 93. In addition, a nozzle plate constituting the droplet discharge surface 20P is attached to one end surface of the head body 90. In the nozzle plate, a plurality of nozzles 91 for discharging the liquid crystal 250 are opened corresponding to the liquid crystal chambers 93. A flow path is formed from each liquid crystal chamber 93 toward the corresponding nozzle 91. On the other hand, a diaphragm 94 is attached to the other end surface of the head body 90. This diaphragm 94 constitutes the wall surface of the liquid crystal chamber 93. Piezo elements (piezoelectric elements) 92 are provided outside the diaphragm 94 so as to correspond to the liquid crystal chambers 93. The piezo element 92 is obtained by sandwiching a piezoelectric material such as quartz with a pair of electrodes (not shown).

  FIG. 5 is a schematic diagram showing the drive voltage waveform W1 of the piezo element and the operation of the ejection head 20 corresponding to the drive voltage. Below, the case where the drive voltage of the waveform W1 is applied with respect to a pair of electrode which comprises the piezo element 92 is demonstrated. First, in the positive gradient portions a1 and a3, the piezoelectric element 92 contracts to increase the volume of the liquid crystal chamber 93, and the liquid crystal 250 flows from the reservoir 95 into the liquid crystal chamber 93. In the negative gradient portion a <b> 2, the piezoelectric element 92 expands to reduce the volume of the liquid crystal chamber 93, and the pressurized liquid crystal 250 is discharged from the nozzle 91. The application amount of the liquid crystal 250 is determined by the amplitude of the drive voltage waveform W1 and the number of times of application. Further, the piezoelectric element 92 provided in the ejection head 20 functions as a heater as will be described later.

  On the other hand, in the droplet discharge device 10 shown in FIG. 3, the stage moving means 14 is configured by a guide rail (not shown) extending in the Y direction, a slider (not shown) movable along the guide rail, and the like. As the slider driving means, for example, a linear motor or the like is employed. Accordingly, the stage 46 disposed above the slider can be moved along the Y direction, and can be stopped at an arbitrary position. Furthermore, the stage 46 can be rotated around the Z axis by connecting the ejection head 20 to another motor or the like, and can be stopped at an arbitrary position.

  In addition, the droplet discharge device 10 shown in FIG. The operation control unit 80 can move the ejection head 20 to a predetermined position by outputting an operation signal to the head moving unit 16 and the linear motor 62. Further, by outputting a drive signal to the piezo element 92 of the ejection head 20, a predetermined amount of the liquid crystal 250 can be ejected from the ejection head 20 at a predetermined timing. On the other hand, the operation control unit 80 can move the stage 46 to a predetermined position by outputting an operation signal to the stage moving unit 14.

  On the other hand, a temperature sensor (not shown) is attached to the ejection head 20 in order to adjust the temperature of the liquid crystal 250. Further, since the liquid crystal 250 is supplied from the liquid crystal tank 86 to the discharge head 20 via the liquid crystal flow path 87, the liquid crystal tank 86 and the liquid crystal flow path 87 are provided with a heater and a temperature sensor (not shown). . The droplet discharge device 10 also includes a temperature sensor (not shown) that measures the outside air temperature. In addition, it is preferable to provide a heater and / or a cooler and a temperature sensor (not shown) also on the stage 46 on which the substrate 210 on which the liquid crystal 250 is discharged is placed. The droplet discharge device 10 is provided with a temperature control unit 82, and controls the operation of each heater, the piezo element 92, etc. while monitoring the measurement results by the above-described temperature sensors, thereby controlling the liquid crystal 250 at a predetermined temperature. It can be adjusted to.

[Droplet ejection method]
Next, a method of discharging the liquid crystal 250 using the above-described droplet discharge device 10 will be described with reference to FIGS. FIG. 6 is an explanatory diagram of the manufacturing method of the liquid crystal device according to the present embodiment.

  First, as shown in FIG. 6A, a sealing material 252 made of a thermosetting resin or the like is applied to the periphery of an image display area of a TFT array substrate (hereinafter simply referred to as a substrate) 210. The sealing material 252 is applied by screen printing, a dispenser, or the like. Note that particles may be included in the sealant 252 in order to make the gap between the substrates constant. On the other hand, an alignment film is formed on the surface of the substrate 210, and a rubbing process is performed in a direction indicated by a broken line 211 in FIG. 6 to regulate the alignment direction of the liquid crystal molecules. The substrate 210 is placed on the upper surface of the stage 46 in the droplet discharge device 10 shown in FIG. Hereinafter, a case where the substrate 210 is placed with the orientation regulating direction of the substrate 210 aligned with the X direction of FIG. 3 will be described as an example.

  Next, an operation signal is output from the operation control unit 80 shown in FIG. 3 to the stage moving unit 14 and / or the head moving unit 16, and the ejection head 20 is arranged above the coating start position on the substrate 210. The discharge of the liquid crystal 250 by the discharge device 10 is started. Here, in general, the liquid crystal 250 is a highly viscous fluid and exhibits a viscosity of 50 cps or more at room temperature (20 ° C.). Such a highly viscous fluid is difficult to be ejected from a minute diameter nozzle in the ejection head 20. In order to stably discharge the liquid crystal 250 by the discharge head 20, it is necessary to reduce the viscosity of the liquid to about 10 cps, for example. Therefore, the temperature control unit 82 shown in FIG. 3 drives the heaters mounted on the liquid crystal tank 86 and the liquid crystal channel 87 and drives the piezo element 92 as follows.

  The temperature control unit 82 applies a voltage having a predetermined frequency to the piezo element 92, thereby causing the piezo element 92 to constantly vibrate so that the liquid crystal 250 is not discharged from the discharge head 20. Here, the voltage applied to the piezo element 92 is about 30% of the rated voltage applied to discharge the liquid crystal 250. As a result, the liquid crystal 250 in the ejection head 20 is heated by the heat of the piezo element 92 that has generated heat due to micro-vibration, the temperature is maintained at about 70 ° C., and the viscosity is reduced to about 10 cps. 250 can be discharged, and a predetermined amount of the liquid crystal 250 can be discharged accurately.

  The temperature controller 82 also controls the voltage value or frequency applied to the piezo element 92 based on the measurement result from the temperature sensor that detects the outside air temperature, and maintains the viscosity of the liquid crystal 250 at the optimum temperature for ejection. To do. That is, since the liquid crystal 250 always emits heat to the external environment, the temperature control unit 82 compensates for this by increasing the voltage value applied to the piezo element 92 as the temperature difference between the outside air temperature and the liquid crystal temperature increases. Control either frequency or waveform.

  Then, as described above, in a state where the liquid crystal 250 is heated to a predetermined viscosity by the temperature control unit 82, a drive signal is output from the operation control unit 80 to the piezo element 92 of the ejection head 20, and the ejection is performed. The liquid crystal 250 is discharged from the head 20. Further, the liquid crystal 250 is discharged from the discharge head 20 while moving the stage 46 and / or the discharge head 20. By adjusting the relative speed between the ejection head 20 and the stage 46, the ejection frequency of the liquid crystal 250 by the ejection head 20, the inclination angle of the ejection head 20 around the Z axis, and the like, the coating amount per unit area can be adjusted. Can be controlled. Thereby, as shown in FIG. 6B, the liquid crystal 250 is applied to the inside of the sealing material 252 in the substrate 210. Note that particles may be included in the liquid crystal 250 in order to make the gap between the substrates constant.

  Here, the temperature in the ejection head 20 is lowered by the newly supplied liquid crystal 250. Therefore, the temperature control unit 82 controls any one of the voltage value, frequency, and waveform applied to the piezo element 92 to slightly vibrate immediately after application of the liquid crystal 250 to the substrate 210 in order to compensate for this temperature drop. The temperature is increased to maintain the viscosity of the liquid crystal 250 at an optimum temperature for ejection. Thereby, when the liquid crystal 250 is applied thereafter, the liquid crystal 250 can be discharged from the discharge head 20 very smoothly.

  Note that the control of the temperature control unit 82 based on the temperature drop of the discharge head 20 is stable before the liquid crystal 250 is discharged onto the substrate 210 by preventing thickening in the discharge head 20 and precipitation of liquid solids. It is also performed immediately after the preliminary discharge called flushing for performing discharge. In other words, immediately after the flushing, the temperature control unit 82 controls the voltage value, frequency, or waveform applied to the piezo element 92 to slightly vibrate to increase the temperature, and the viscosity of the liquid crystal 250 is optimal for ejection. Maintain temperature.

  Then, the color filter substrate 220 (see FIG. 1) is bonded to the substrate 210 to which the liquid crystal 250 is applied. Specifically, bonding is performed in a vacuum while adjusting the gap between the substrates to be uniform, and heating is performed at about 120 ° C. for about 10 minutes in a heating furnace, whereby the sealing material 252 is cured and both the substrates are cured. Glue the substrates. Note that the liquid crystal 250 comes into contact with the sealing material 252 at the stage where the two substrates are bonded together, but the resin constituting the sealing material is not mixed into the liquid crystal 250 after the sealing material 252 is cured. Thus, the liquid crystal device 200 shown in FIG. 1 is completed.

  As described above, according to the droplet discharge device and the droplet discharge method according to the above-described embodiment, a voltage of a predetermined frequency is applied to the piezo element 92, and the piezo element is vibrated to the extent that the liquid crystal 250 is not discharged. The liquid crystal 250 of the discharge head 20 can be quickly heated by generating heat at 92 so that the viscosity of the liquid crystal 250 can be discharged satisfactorily. As a result, the liquid crystal 250 can be discharged quickly, and the productivity of the liquid crystal device 200 can be increased and the productivity can be greatly improved. In addition, the temperature control unit 82 continuously applies a voltage of a predetermined frequency to the piezo element 92 during the liquid crystal 250 discharge process, and causes the piezo element 92 to vibrate slightly. It can be heated to a suitable temperature so that good discharge by the discharge head 20 is possible.

  In addition, immediately after the liquid crystal 250 is discharged, the temperature control unit 82 adjusts the voltage value, frequency, or waveform of the voltage applied to the piezo element 92 so as to slightly vibrate the piezo element 92, thereby generating a heat value of the piezo element 92. Therefore, when the temperature of the liquid crystal 250 of the discharge head 20 decreases immediately after the liquid crystal 250 is discharged, the amount of heat generated by the piezo element 92 is increased, and a good discharge can be quickly achieved. Further, the temperature control unit 82 determines any one of a voltage value, a frequency, or a waveform of a voltage applied to the piezo element 92 to slightly vibrate the piezo element 92 based on the temperature difference between the liquid crystal 250 of the ejection head 20 and the outside air. Since the adjustment is performed, the influence on the viscosity of the liquid crystal 250 due to the outside air temperature can be suppressed as much as possible, and a state in which satisfactory discharge can always be achieved can be achieved. According to the liquid crystal device manufactured by the droplet discharge method, the liquid crystal 250 is quickly discharged onto the substrate and applied to increase the production efficiency, so that the cost can be reduced.

  In the above embodiment, the piezo element 92 provided in the ejection head 20 is slightly vibrated to heat the liquid crystal 250 in the ejection head 20, but a heater for heating the liquid crystal 250 in the ejection head 20 is separately provided. The liquid crystal 250 in the discharge head 20 may be heated together with the heater. In this case, as the control by the temperature control unit 82, the current applied to the heater and the piezo are applied so that the heater and the piezo element 92 are always driven and the total amount of heat generated by the heater and the piezo element 92 is constant. The voltage value, frequency, or waveform applied to the element 92 is controlled. And according to said structure, since the liquid crystal 250 is heated with the piezo element 92 with a heater, the liquid crystal 250 of the discharge head 20 is heated more rapidly, and the viscosity of the liquid crystal 250 is made into the state which can discharge favorably. Can do.

  In this embodiment, the sealing material 252 is formed on the TFT array substrate 210 shown in FIG. 1, and the liquid crystal 250 is discharged onto the TFT array substrate 210 to be bonded to the color filter substrate 220. However, conversely, the sealing material 252 may be formed on the color filter substrate 220, and the liquid crystal 250 may be discharged onto the color filter substrate 220 to be bonded to the TFT array substrate 210. In addition, in order to promote the wetting and spreading of the applied liquid crystal 250, when the substrate is heated by a heater or the like provided in the table, the sealing material may be cured before the two substrates are bonded together. In this case, it is preferable that the sealing material 252 is formed on one of the TFT array substrate 210 and the color filter substrate 220, the liquid crystal 250 is applied to the other substrate, and the two substrates are bonded together. Thereby, the sealing material 252 is not cured before the two substrates are bonded together, and the two substrates can be bonded together satisfactorily.

[Electronics]
Next, an example of an electronic device including a liquid crystal device is described with reference to FIGS. FIG. 7 is a perspective view of the mobile phone. The liquid crystal device formed by the above method is disposed inside the housing of the mobile phone 3000.
And according to the electronic device comprising the mobile phone 3000, an electronic device equipped with a low-cost liquid crystal device can be provided.

  Note that the liquid crystal device formed by the above method can be applied to various electronic devices other than cellular phones. For example, LCD projectors, multimedia personal computers (PCs) and engineering workstations (EWS), pagers, word processors, TVs, viewfinder type or monitor direct view type video tape recorders, electronic notebooks, electronic desk calculators, car navigation systems The present invention can be applied to electronic devices such as a device, a POS terminal, and a device provided with a touch panel.

  It should be noted that the technical scope of the present invention is not limited to the above-described embodiments, and includes those in which various modifications are made to the above-described embodiments without departing from the spirit of the present invention. That is, the specific materials and configurations described in the embodiments are merely examples, and can be changed as appropriate.

It is a top view of a liquid crystal device. It is a sectional side view of the liquid crystal device of the part equivalent to the HH 'line of FIG. It is a schematic external perspective view of a droplet discharge device. It is explanatory drawing of the structural example of an ejection head. It is a figure which shows the voltage waveform to a piezoelectric element, and operation | movement of an ejection head. It is explanatory drawing of the method of apply | coating a liquid crystal and manufacturing a liquid crystal device. It is a perspective view of the mobile phone which is an electronic device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Droplet discharge apparatus, 20 ... Discharge head, 82 ... Temperature control part (control means), 92 ... Piezo element (piezoelectric element), 200 ... Liquid crystal device, 3000 ... Cell-phone (electronic device)

Claims (8)

A liquid droplet ejection apparatus for ejecting liquid crystal by vibration of the piezoelectric element from an ejection head equipped with a piezoelectric element,
Control means for vibrating the piezoelectric element so that the liquid crystal is not discharged from the discharge head;
Wherein the control means, by Rukoto the piezoelectric element to generate heat by vibrating such that the liquid crystal from the ejection head is not ejected, to reduce the viscosity of the liquid crystal,
Adjusting the waveform applied to the piezoelectric element so as to vibrate the piezoelectric element so that the liquid crystal is not discharged from the discharge head after discharging the liquid crystal having a reduced viscosity, thereby increasing the amount of heat generated by the piezoelectric element. A droplet discharge apparatus characterized by 2. The liquid droplet according to claim 1 , wherein the control unit continuously applies a voltage of the predetermined frequency to the piezoelectric element and vibrates the piezoelectric element during an ejection step of ejecting the liquid crystal. Discharge device. 3. The droplet discharge device according to claim 1, wherein the control unit adjusts a waveform to be applied to the piezoelectric element based on a temperature difference between the liquid crystal in the discharge head and the outside air. The ejection head includes a heater that heats the liquid crystal, and the control unit generates a current to the heater and a voltage to the piezoelectric element so that a total amount of heat generated by the heater and the piezoelectric element is a predetermined value. the apparatus according to any one of claims 1 and controls 3. A droplet discharge method for discharging liquid crystal by vibration of the piezoelectric element from an ejection head including a piezoelectric element,
Said piezoelectric element to vibrate the piezoelectric element so as not to eject the liquid by heating to reduce the viscosity of the liquid crystal by Rukoto,
Adjusting the waveform applied to the piezoelectric element so as to vibrate the piezoelectric element so that the liquid crystal is not discharged from the discharge head after discharging the liquid crystal having a reduced viscosity, thereby increasing the amount of heat generated by the piezoelectric element. A method for ejecting droplets. 6. The droplet discharging method according to claim 5 , wherein, during the discharging step of discharging the liquid crystal , the voltage of the predetermined frequency is continuously applied to the piezoelectric element to vibrate. 7. The droplet discharge method according to claim 5 , wherein a waveform applied to the piezoelectric element is adjusted to vibrate the piezoelectric element based on a temperature difference between the liquid crystal in the discharge head and outside air. . Wherein the heater is provided in the discharge head, in order to the total heating value of the heater and the piezoelectric element to a predetermined value, 5 to claim, characterized in that controlling the current and voltage to the piezoelectric element to the heater the droplet discharging method according to any one of 7.

Images