JP4790240B2 - Feedback control type dry spacer sprayer. - Google Patents

Description

  The present invention relates to a dry-type spacer spraying device for spraying spherical spacers of a minute specified size in order to accurately and uniformly provide a gap between display elements to be superimposed on a liquid crystal cell in a liquid crystal display substrate manufacturing process, More specifically, the present invention relates to a feedback-type dry spacer spraying device that detects the charge amount of the sprayed spacers and enables the spacers to be sprayed more accurately based on the detected value.

  In the process of assembling the liquid crystal cell, in order to accurately and evenly provide the gap between the display elements, spherical spacers of a minute specified size are dispersed on the substrate. There are wet spraying method and dry spraying method.

  Here, the wet spraying method is a method in which spacers are dispersed in a solvent and sprayed as a liquid to uniformly distribute the spacers on the substrate. In this method, the apparatus is inexpensive and the spacers themselves are charged. Therefore, there is an advantage that the external static electricity and the influence of the surroundings can be minimized, and it is widely used in twisted nematic liquid crystal devices and super twisted nematic liquid crystal devices.

  However, in this method, the solvent as a liquid needs to be surely dried before reaching the substrate, otherwise the spacers aggregate as the solvent on the substrate dries, and therefore the solvent is volatile. The liquid inside must be dried at a high temperature in the chamber. Further, since aggregation is likely to occur during the spraying process, strict management is required from the preparation stage of the spacer dispersion liquid to the spraying moment in the apparatus.

  On the other hand, the dry spraying method is a method of supplying and spraying the spacer itself, and since it is not necessary to add anything to the spacer, preparation is very simple. The dry spraying method is generally divided into a charging method in which the spacer is pumped and sprayed on an air current, and an electrostatic method in which the spacer is forcibly charged and sprayed. Since it can be sprayed without being placed in an airflow for charging, it has the advantage that the use efficiency of the spacer is improved. However, it is not suitable for a wide range of spraying, and the spacer charged at a high voltage reaches the substrate as it is. Therefore, there is a problem in that there is a risk of pattern destruction on the substrate. On the other hand, in the charging method, it is difficult to separate and disperse the spacers, and various ideas and know-how are required.

  By the way, liquid crystal cells are now widely used as display elements, and liquid crystal cells with different display structures are used according to various requirements. However, this kind of increase and size increase As the range of applications as display elements expands, the requirements have diversified, and various types of spacers have been developed. For example, spacers having a minute particle diameter of about 1 μm have been developed. In addition, there is a demand for spreading the substrate material not only on glass but also on plastic films. On the other hand, the current spraying device does not necessarily satisfy the performance including the high speed and reliability. Therefore, there is a demand for a spacer spraying device capable of meeting various demands with higher performance. ing.

Therefore, in the past, the present applicant has responded to such demands in the past, so that the preparation and handling of the spacer is simple, and it can be applied to a large substrate, from a small diameter spacer to a large diameter spacer, We have proposed dry spacers that can be sprayed not only on glass substrates but also on film substrates, with high spacer spraying efficiency, high speed spraying, and high reliability.
JP 2002-148635 A

  By the way, in recent years, the display size has been particularly demanded, and at the same time, the range of application as a display element has further expanded. There is a fact that has been needed.

  Therefore, the present invention is different from conventional spacer volume and weight weighing methods, and by adopting a new charge amount detection feedback method, a dry spacer spraying method capable of meeting even more severe requirements in the future and An object is to provide an apparatus.

  The present invention is a dry spacer spraying device having a weighing chamber and a spacer pressure feeding pipe, provided with a spraying spacer charge amount detection sensor for monitoring the charge amount of the spray spacer, and monitoring the charge amount by the sensor simultaneously with the start of spraying, The spraying is continued until the monitor value reaches the set spray charge amount, and spraying can be terminated when the monitor value reaches the set spray charge amount.

  In the present invention, the amount of charged spacers is detected and the amount of dispersed spacers is controlled based on the detected value. That is, the present invention is fundamentally different from the conventional spreader, and before the spraying, the spacer spray amount is sprayed after the weight or volume is weighed by a physical method, or sprayed while weighing. Since this is a feedback system that controls the delivery amount according to the detection amount and at the same time determines the total application amount based on the detection result and completes the application, the conventional spacer Unlike volume and weight weighing methods, stable spacer spraying is possible.

  The dry spacer spraying apparatus of the present invention has a weighing chamber, a spraying chamber, a spacer pressure feed pipe, and a spray nozzle provided in the spray chamber, and detects the charge amount of the spray spacer on the spacer pressure feed pipe or the spray table. A spacer charge amount detection sensor is provided for feeding back the detected charge amount.

  At the same time as the start of spraying the spacer, the charge amount of the spacer sprayed by the sensor is monitored and the detected value is fed back, and spraying is continued until the fed back monitor value reaches the set spray charge amount. The spraying can be terminated when the set spraying charge amount is reached.

  Here, in order to stably feed the spacer into the weighing chamber, a hopper block having vibration, a buffer block, and a feed block may be provided so that each block can be independently controlled to vibrate. A spacer amount detection sensor for detecting the upper limit and the lower limit of the spacer amount in the buffer may be provided in the buffer block.

  An embodiment of a dry spacer spraying apparatus (hereinafter simply referred to as “spreading apparatus”) of the present invention will be described with reference to the drawings. FIG. 1 is an overall view of the spraying apparatus of the present embodiment. Unit B is a spray chamber. That is, the spraying apparatus of the present embodiment has the spraying chamber B and the spacer weighing unit A as main units.

  And the spray nozzle B1 is attached to the ceiling part in the spray chamber B, and this spray nozzle B1 is connected with the weighing chamber A2 in the weighing unit A via the spacer pressure feed pipe A5.

  A work table B2 on which a substrate for spraying spacers is placed is disposed below the spray chamber B, and an exhaust port B3 is provided below the work table B2.

  Next, in the spacer weighing unit A, a weighing control box A1 and a weighing chamber A2 are arranged. Further, in the weighing chamber A2, as shown in FIG. A feeder unit A200 for controlling the delivery to A5 is accommodated, and the delivery spacer is guided to the nozzle B1 in the spraying chamber by the pressure feeding pipe A5.

  Further, in the vicinity of the pressure feeding pipe A5 in the spacer weighing unit A, a charge amount sensor A3 for detecting the amount of the sending spacer (both a contact type and a non-contact type sensor can be considered, but in this embodiment, a non-contact type) Further, a control unit A4 in which a power source for controlling the entire apparatus, a CPU, and the like are accommodated is disposed on the lower side in the spacer weighing unit A.

  In other words, in the spraying device of this embodiment, the spacer spray amount is measured after the weight and volume are weighed by a physical method before spraying, or is not sprayed while weighing, but the spray spacer amount is regarded as an electrical signal. It is possible to control the delivery amount according to the detected amount, and at the same time, the feedback method to judge the entire spray amount based on the detection result and complete the spraying is enabled. This is a fundamentally different part. As a result, not only the performance of the apparatus was improved, but also a significant reduction in apparatus cost and running cost could be achieved, and operational advantages could be confirmed.

  Next, the weighing chamber A2 will be described with reference to FIG. 2. A feeder unit A200 shown in FIG. 3 is accommodated in the weighing chamber A2, and a spacer supply hopper A201 is provided in the feeder unit A200 above. A chamber door A20 for inserting a spacer is prepared.

  Further, a pipe A21 that applies an internal pressure (spacer pressure feeding pressure) to the weighing chamber A2 is connected to the weighing chamber A2. In FIG. 2, A22 indicates the wiring connected to the electrical components used in the feeder unit A200 accommodated in the weighing chamber A2, and A23 indicates the piping connected to the external exhaust. Are connected to the feeder unit A200. Furthermore, A5 is a pressure feed pipe for sending a spacer to the spray nozzle B1 attached to the ceiling of the spray chamber B, and this pressure feed pipe A5 is also connected to the feeder unit A200.

  Next, the feeder unit A200 will be described with reference to FIG. 3. In this embodiment, the feeder unit A200 includes a hopper block, a buffer block, a feed block, and a sensor.

  First, the hopper block includes a hopper A201 for supplying a spacer from the outside, a hopper mounting plate A202, and a diaphragm A203. Further, although not shown, the diaphragm A203 includes a piezo as a vibration source. An element is provided.

  Next, the buffer block has a hole A212 through which a spacer is sent out by vibration at the bottom, and is connected to a buffer A210 for securing a certain amount of spacer and a piezo element as a vibration source to vibrate the buffer. It consists of a diaphragm A211.

  The feeder block is composed of a feeder A220 having a lower oblique groove A222 so that the spacer flows, and a diaphragm A221 that is connected to a piezo element as a vibration source and vibrates the buffer. And, one end of the pressure feeding pipe A5 for guiding the spray spacer to the spray nozzle B1 is arranged immediately below the feeder groove A222.

  In addition, there are fiber beam sensors A204 and 205 for detecting the spacer supply upper limit of the buffer A210 as sensors, and a sensor block for detecting the lower limit. The sensor block is made of metal inserted in the middle of the buffer A210. The pipe A230, a sealed shutter box (not shown) having a solenoid for controlling the opening and closing of the pipe, and a sensor amplifier A231 (both sensors can be a contact type or a non-contact type. In this embodiment, the non-contact type is used. Is used). Further, the shutter box has a discharge port A233 for a spacer sent out from the metal pipe A230, and the sending spacer is exhausted by a pipe A23 from the outside.

  Next, the circuit configuration of the present embodiment will be described. FIG. 4 is a diagram showing the overall circuit configuration of the control of the weighing unit A. In FIG. 1, reference numeral 1 denotes a power source that controls the entire apparatus, a CPU, and the like. CPU of the control unit A4 is shown. The CPU control line A21 is connected to each circuit of the weighing control box A1, and the output of each circuit is connected to the control component of the weighing chamber A2 and the sensor amplifier A3 of the spacer pressure feeding pipe A5.

  In the figure, reference numeral 2 denotes an internal pressure setting control circuit having a D / A converter of the weighing chamber A2, and the output voltage is connected to the electropneumatic regulator 3. Then, the output pressure gas is sent to the weighing chamber A2 through a pipe (A21 in FIG. 2), and as a result, the set internal pressure is given to the entire weighing chamber.

  In the figure, 4 is a hopper piezo driver having an oscillator, and 5 is a piezo element connected to the output. Then, the hopper vibrates according to the control command of the CPU 1 and the spacer is supplied to the buffer (A210 in FIG. 3). Reference numeral 6 denotes a buffer piezo control circuit and a piezo driver, and 7 denotes a piezo element connected to the output. Then, the buffer is vibrated by the control instruction of the CPU 1, and the spacer is dropped into the feeder groove (A222 in FIG. 3). The buffer piezo control circuit 6 is a general circuit and is not particularly shown, but has an oscillator and a frequency modulation circuit, and the amount of spacers sent from the buffer can be controlled by setting the frequency.

  In the figure, 8 is a feeder driver having an oscillator, 9 is a piezo element connected to the output, 10 is a fiber sensor amplifier, and A204 is a light emitting fiber head.

  Next, the sensor is disposed between the lower end of the hopper A201 (spacer outlet) and the upper end of the buffer A210, and is provided to determine the upper limit setting position of the buffer capacity of the spacer supplied from the hopper.

  A231 is a charge sensor amplifier, which is set near the metal pipe A230. One end of the pipe is inserted in the middle of the buffer A210, and is provided to determine the lower limit setting position of the buffer capacity of the spacer supplied from the hopper. On the opposite side of the pipe, there is a shutter box A232 that houses a shutter solenoid, and the pipe is electrically insulated. In addition, 11 is a solenoid driver, 12 is a shutter solenoid, and the pipe can be opened and closed by a shutter ON-OFF control command of the CPU 1. In the figure, reference numeral 13 denotes a spray amount control circuit, to which a control line from the CPU 1 and an output line of the spray charge sensor A3 connected to the pressure feeding pipe A5 are connected.

  Next, spray control and timing will be described. FIG. 5 is a diagram showing an internal basic circuit of the spray amount control circuit 13, and FIG. 6 is a spray timing chart. Spacer pumping is sprayed connected to the transfer A5. The output of the charge detection sensor A3 is connected to an absolute value amplifier 141, and the output of the amplifier 141 is connected to each input of the four comparators 143 to 146.

  Next, in the figure, reference numeral 142 denotes a D / A comparator, and the CPU 1 sets the application amount to the D / A comparator through 142a. The output of the D / A comparator 142 is equally divided by four resistors R, and each equal output is connected to the other input of each of the comparators 143 to 146. As a result, after the start of spraying, the comparator output is sequentially turned on every time the set spray charge amount reaches ¼. In FIG. 6, TCH1 indicates a spraying flag, TCH2 indicates the charge amount of the pressure feeding pipe A5, that is, the output of the spray charge detection sensor A3, and 2a, 2b, 2c, and 2d are 1/4 to 4 of the set spray charge amount. / 4 is shown. Further, the comparator outputs 146b, 145b, 144b, and 143b in FIG. 5 correspond to the TCH21, TCH22, TCH23, and TCH24 in FIG.

  In this embodiment, a multiplexer nozzle is used as the spray nozzle B1, but FIG. 7 is a conceptual view of a spray area by the multiplexer nozzle. SPA 1 to 4 in the figure are spray areas 1 to 4 in the multiplexer nozzle. The timing is shown. That is, in FIG. 7, the spray glass (square outer periphery) and the spray area (SPA1 to SPA4) at each timing are shown, and the virtual nozzle B1 is shown at the center.

  Next, the principle of the spraying operation will be described below in the order of the normal spraying operation based on a specific embodiment. It is assumed that spacers are supplied to the hopper (A201 in FIG. 3) of the feeder unit.

(1) Scattering (charging) amount setting When a charging amount (Q in this embodiment) corresponding to the desired number of spraying is set from the device panel, the spattering amount control circuit in the weighing control box (A1 in FIG. 1) is set in the CPU1. The charge amount is set in the D / A converter (142 in FIG. 5) (13 in FIG. 4).

(2) Calibration operation switch ON
By pressing the calibration switch, the pre-operation processing is completed and the spray calibration operation is started. Here, “spreading calibration” refers to automating the normal dummy spraying by searching for the appropriate control condition parameters for the set spraying (charging) amount, setting the calibration parameters, and starting the normal spraying operation. It is to reduce manual work, and as a result, it is possible to quickly and stably start up a spraying line. In the case of spraying without changing the spraying conditions such as the set spraying (charging) amount as before, the calibration operation is not necessary, but in this embodiment, it is assumed that the charge amount is newly set.

(3) Pre-operation processing As pre-calibration processing, pressure feed output and spacer supply to the buffer are performed.
First, the control CPU 1 sets a prescribed pressure in the D / A converter of the weighing chamber internal pressure setting control circuit (2 in FIG. 4) and turns on the electropneumatic regulator (3 in FIG. 4). At the same time, the hopper piezo driver (4 in FIG. 4) is turned on, and the hopper (A201 in FIG. 3) of the feeder unit is vibrated to ensure an appropriate spacer amount in the buffer A210. The proper spacer amount means that there is a spacer filling surface between the fiber sensor 10 that detects the upper limit setting position of the buffer capacity described in the overall circuit configuration and the charging sensor A 231 that detects the lower limit setting position. In the detection method of the fiber sensor 10, the vibration of the hopper is intermittently operated, and the supply to the hopper is ended when the sensor is turned on when the vibration is turned off.

  On the other hand, the detection method of the lower limit position is as follows. That is, first, the shutter solenoid is turned on for a moment at the detection timing. At this time, if there is a spacer up to the tip of the metal pipe 230, the spacer is passed through the metal pipe by the pressure difference between the internal pressure of the weighing chamber (A2 in FIG. 2) and the pipe connected to the shutter portion and the exhaust (A23 in FIG. 2). Flows rapidly and frictional charging occurs in the metal pipe. The charge amount at this time is detected by the charge sensor A231. Although not shown, it is naturally necessary to ground the pipe and initialize the charge prior to detection. In addition, prior to spraying, it is necessary to apply a high voltage to the inner wall of the spray chamber (B in FIG. 1).

(4) Calibration operation start Next, the CPU 1 starts the piezo vibration operation of the buffer A210 and the feeder A220 of the feeder unit (FIG. 3). As described above, the buffer A210 has a frequency modulation circuit, and the spacer delivery amount can be controlled by the spraying amount and the spacer output (A212).
On the other hand, the feeder A220 operates at a predetermined set frequency so that the spacer delivered from the buffer A210 continuously generates a uniform flow in the feeder groove A222.
In the present embodiment, these two controls are very important. The buffer A210 is controlled by controlling the spacer feed amount in accordance with the variable set spraying amount to make the processing time uniform (which is an absolute condition for an in-line mass production machine) and the flow of the spacer as a property of the powder. It is necessary to correct the characteristics that change every moment.
For this reason, as described above, it is important for the present apparatus not only to make the amount of spacers contained in the buffer uniform, but also to control the amount of spacers delivered.
In addition, the spacer whose frequency modulation circuit is controlled in the buffer A210 as in this embodiment is likely to cause an intermittent flow of the delivery amount. In the apparatus of this embodiment in which spacers with such an increase / decrease are sprayed while feedback-controlling the pressure feed pipe (A5 in FIG. 3), the dispersion amount for the delay time flowing in the pipe is varied. By delaying the spacer with the increase / decrease in this way from the feeder groove A222 by dropping the spacer which has become a continuous and uniform flow by the control of the feeder A220, the spacer is sucked into the feeding pipe A5 by the internal pressure of the weighing chamber (FIG. 2) and dispersed. The amount of time is kept constant and the number of sprays is stabilized.

(5) Calibration Operation Control Next, the calibration operation will be described with a focus on the spacer feed amount control of the buffer A210. Initial control parameters determined in advance at the start of the calibration operation (the frequency control value will be described as N in this embodiment). Start calibration spraying control after setting.

  When the piezo-vibration operation of the buffer A210 and the feeder A220 is started, the spacer dropped from the feeder groove A222 is sucked into the pressure feeding pipe A5 immediately below by the internal pressure of the entire weighing chamber A2, and diffused by the spraying pressure from the multiplexer nozzle in the spraying chamber. Then, the region 1 starts to be sprayed (SPA1 in FIGS. 6 and 7). Then, after resetting the grounding of the pressure feeding pipe A5, the scattering charge detection sensor A3 starts measuring the amount of dispersion (charging) with the absolute value amplifier 141 (Note that the absolute value amplifier 141 always has + It is provided for handling as polarity.)

At the same time, the CPU 1 starts measuring the spraying time. When the charge measurement amount reaches Q · ¼ in this way, the CPU senses the comparator output 146b and commands the spraying of the spraying region 2 (SPA2 in FIGS. 6 and 7).
In addition, when the dispersion measurement time of the dispersion 1 is longer than a specified value (in the present embodiment, it is assumed that T = 3 seconds) T seconds, the spacer delivery amount frequency control value of the buffer A210 is shorter to N-1. In that case, set N + 1 and continue spraying.
Similarly, when the measured charge amount reaches Q · 2/4, the comparator output 145b is sensed, and the spray command for the spray region 3 (SPA 3 in FIGS. 6 and 7) and the setting of the spacer sending amount frequency control value are sprayed.
Thus, when the charge measurement amount reaches Q · 3/4, the comparator output 144b is sensed, the spraying command for the spraying region 4 (SPA4 in FIGS. 6 and 7) and the setting of the spacer feed amount frequency control value are sprayed and sprayed. When the comparator output 143b whose measured value reaches Q · 4/4 is sensed, the calibration spraying for one glass is finished. At this time, it is determined whether each of the spraying times Ts of the spraying SPAs 1 to 4 (explained as T ± 1 second in this embodiment) has entered 2 <Ts <4 seconds. If the determination result is GO, the calibration operation is completed. On the other hand, if the determination result is NG, the second calibration spraying is started again, and the calibration operation is completed at the GO determination time point.

(6) Spraying operation switch ON
As the pre-spreading process, pressure feed pressure output and spacer supply to the buffer are performed.

(7) Starting spraying operation In the same manner as the calibration operation, the piezo vibration operation of the buffer A210 and the feeder A220 of the feeder unit (FIG. 3) is started. Naturally, the frequency control value of the buffer starts operation from the value at the time of completion of the calibration operation.

(8) Scattering operation control In the same sequence as the calibration operation, spraying is performed while controlling the buffer spacer feed rate frequency. However, the measured spraying time Ts differs from the calibration operation in that an error occurs if the measured spraying time Ts exceeds the specified range. .
In this way, it is possible to obtain stable spraying and spraying time (4 Ts) by controlling the spacer feed amount. In the case of an in-line spreader, the buffer control is performed in the pre-spreading process, and if the buffer capacity does not reach a certain value within a specified time, an alarm is given that the hopper spacer is empty.

  Thus, in this embodiment, unlike the conventional spraying device and spraying method, since the closed weighing chamber is provided, the spacer is exposed to the pressure N2 of the pressure feeding pressure and is not affected by the humidity so far. It is possible to maintain above. In addition, since no external force such as abrasion is applied to the spacer, stable spacer powder can be dispersed without damaging the surface of the spacer or the surface coating film such as the fixed spacer.

  In addition, the use of the spacer charging feedback system eliminates the need for a weighing pan, further eliminates the loss of grinding, and increases the use efficiency of the spacer by about 20 to 25%. Even a small amount of various types of spacers can be sprayed with only the buffer capacity, and the surroundings are hardly soiled by the spacers. Therefore, a great effect was obtained such as greatly shortening the cleaning time and labor when changing.

  In addition, the spray charge amount is set and the spray charge real-time measurement amount feedback method is used. It was confirmed that the number complement control and spray charge measurement can be fed back by the sensor on the spray table instead of the pressure feed pipe.

  In this way, the spraying device of the present embodiment that controls the spraying amount as an electric signal is required to ensure the required performance and spraying stability as a sprayer compatible with the large side glass and the recent strong spacer, which will be called the sixth generation in the future. It has a big meaning. 8 and 9 show measured data of the spacer amount (weight), the measured charge amount, and the number of sprays, which are the basis of the basic concept of this embodiment.

  In the present invention, when the spacers are dispersed, the amount of charged spacers is detected and the amount of dispersed spacers is controlled based on the detected value. Therefore, not only the liquid crystal display substrate manufacturing process but also the dry spacer dispersion. It is applicable to all of the above.

1 is an overall view of an embodiment of the present invention. It is a whole block diagram of a weighing chamber. It is a whole block diagram of a feeder unit. It is a whole circuit block diagram of control of a weighing unit. It is an internal basic circuit diagram of a spreading amount control circuit. It is a figure which shows a dispersion | distribution timing chart. It is a spray area conceptual diagram. It is actual measurement data of the spacer amount, the measured charge amount, and the number of sprays. It is actual measurement data of the spacer amount, the measured charge amount, and the number of sprays.

Explanation of symbols

A Spacer weighing unit A1 Weighing control box A2 Weighing chamber A200 Feeder unit A201 Hopper A202 Mounting plate A203 Diaphragm A204, A205 Fiber beam sensor A210 Buffer A211 Diaphragm A212 Spacer feeding hole A220 Feeder A221 Diaphragm A222 Groove A230 Groove A230 A231 Sensor amplifier A232 Shutter box A233 Spacer discharge port A20 Chamber door A21 Piping A22 Wiring A23 Piping A3 Charge amount sensor A4 Control unit A5 Pressure feed piping B Spraying chamber B1 Spray nozzle B2 Work table B3 Exhaust port 1 CPU in control unit
2 Internal pressure setting control circuit 3 Electropneumatic regulator 4 Hopper piezo driver 5 Piezo element 6 Buffer piezo driver 7 Piezo element 8 Feeder driver 9 Piezo element 10 Fiber sensor amplifier 11 Solenoid driver 12 Shutter solenoid 13 Spreading amount control circuit 141 Absolute value amplifier 142 D / A converters 143 to 146 comparators

Claims (2)

A dry spacer spraying device with a weighing chamber and spacer pressure feed piping is equipped with a spray spacer charge amount detection sensor that monitors the charge amount of the spray spacer, and the monitor value is set by monitoring the charge amount with the sensor as soon as spraying starts. It is possible to continue spraying until reaching the spray charge amount, and to stop spraying when the monitor value reaches the set spray charge amount ,
A feedback control type dry spacer spraying device , wherein a spacer delivery mechanism having a hopper block having vibration, a buffer block, and a feed block is provided in the weighing chamber, and each block can independently control vibration . The feedback control type dry spacer spraying device according to claim 1 , wherein a spacer amount detection sensor for detecting an upper limit and a lower limit of the spacer amount in the buffer is provided in the buffer block.

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