JP2013012550A - Phosphor applying apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a partial point defect of a light-emitting element to which a phosphor-containing solution is applied, by stably supplying the phosphor-containing solution to a spray nozzle 12 during spray injection, and by moving the phosphor-containing solution without contaminating impurities therein during non-spray injection.SOLUTION: A phosphor applying apparatus 10 includes a movement adjustment section 18 to adjust movement of a phosphor-containing solution. During spray injection by the spray nozzle 12, the movement adjustment section 18 extrudes the phosphor-containing solution from a pressure tank 15, and supplies the phosphor-containing solution to the spray nozzle 12 by supplying air into the pressure tank 15. On the other hand, during non-spray injection, the movement adjustment section 18 extrudes the phosphor-containing solution from the pressure tank 15, and moves the phosphor-containing solution to a storage tank 14 via the spray nozzle 12 by the supply of the air.

Description

  The present invention relates to a phosphor coating apparatus that sprays a phosphor-containing liquid on a surface of a light emitting element (for example, an LED (light emitting diode)) with a spray nozzle.

  Conventionally, a light emitting device in which a phosphor layer emitting yellow fluorescence is formed on the surface (including a light emitting surface) of a blue LED emitting blue light is known. In this light emitting device, white light can be obtained by mixing the blue light emitted from the blue LED and the yellow light emitted when the phosphor receives the blue light and emits secondary light. That is, a light emitting device (white LED) that emits white light can be realized by a combination of a blue LED and a phosphor layer.

  Here, in forming the phosphor layer on the surface of the LED, for example, the following method is adopted. First, a phosphor that is a solid powder is mixed with a predetermined solution containing alcohol to prepare a phosphor-containing liquid (first liquid). And this fluorescent substance containing liquid is sprayed on the surface of LED using a spray nozzle. Thereafter, a mixed liquid (second liquid) obtained by mixing the organometallic compound and the organic solvent is further applied from above the sprayed phosphor-containing liquid, fired, and hardened. Thereby, said fluorescent substance layer is formed.

  By the way, the above phosphor-containing liquid is filled in a tank in advance, and is supplied from a tank to a spray nozzle by a pump and sprayed from there at the time of spray injection. Although the phosphor-containing liquid is not sprayed, a configuration in which a solution is supplied from a tank to a spray nozzle using a pump is disclosed in Patent Document 1, for example.

  On the other hand, if the phosphor-containing liquid is left as it is when spraying is not performed, the phosphor has a large specific gravity, and thus precipitates in the spray nozzle and the pipe. Therefore, in the conventional phosphor coating apparatus, a circulation pump is used, and when the spray is not sprayed, the phosphor-containing liquid in the pipe is circulated and moved by the circulation pump, thereby suppressing the precipitation of the phosphor. . In addition, said patent document 1 is common with the said conventional fluorescent substance coating device by the point which suppresses precipitation of the substance contained in a solution using a circulation pump.

JP 2007-185565 A (refer to paragraphs [0010], [0067] to [0068], FIG. 2, FIG. 7, etc.)

  However, in the configuration in which the phosphor-containing liquid is supplied from the tank to the spray nozzle at the time of spray injection, the amount of the phosphor-containing liquid applied by spray injection is not stable due to the pulsation of the pump. Therefore, it is desirable to supply the phosphor-containing liquid from the tank to the spray nozzle by a method other than the pump.

  In addition, in the configuration in which the phosphor-containing liquid in the pipe is circulated and moved by a circulation pump to suppress the precipitation of the phosphor when spraying is not performed, since the phosphor in the phosphor-containing liquid is hard particles, A diaphragm (diaphragm) or the like in the pump is scraped by the phosphor, and the scrap is mixed into the phosphor-containing liquid as impurities (contaminant, contaminant). As a result, when the phosphor-containing liquid is sprayed to form a phosphor layer on the surface of the LED and the LED is turned on, a partial point defect due to the above-described impurities occurs, and this causes variations in the illumination intensity of the LED. Cause.

  The present invention has been made in order to solve the above-described problems. The object of the present invention is to stably supply a phosphor-containing liquid to a spray nozzle at the time of spray injection, while mixing impurities at the time of non-spraying. Provided is a phosphor coating apparatus that can move the phosphor-containing liquid without causing a partial point defect of the light emitting element to which the phosphor-containing liquid is applied, thereby reducing variations in illuminance. There is to do.

  The phosphor coating apparatus of the present invention is a phosphor coating apparatus including a spray nozzle that sprays a phosphor-containing liquid on the surface of a light-emitting element, the storage tank storing the phosphor-containing liquid, and the spray nozzle A pressure tank that receives the phosphor-containing liquid supplied from the storage tank; and a movement adjusting unit that adjusts the movement of the phosphor-containing liquid, and the movement adjusting unit is configured to perform spraying by the spray nozzle, By supplying air to the inside of the pressure tank, the phosphor-containing liquid is pushed out from the pressure tank and supplied to the spray nozzle. On the other hand, when spraying is not performed, the phosphor is supplied from the pressure tank by supplying the air. The contained liquid is extruded and moved to the storage tank through the spray nozzle.

  According to the above configuration, the phosphor-containing liquid is stored in the storage tank, supplied from the storage tank to the spray nozzle through the pressure tank, and sprayed from the spray nozzle to the surface of the light emitting element (for example, LED). Is done. Thereby, a fluorescent substance is apply | coated to the surface of a light emitting element.

  Here, at the time of spray injection, the movement control unit pushes out the phosphor-containing liquid from the pressure tank by supplying air to the pressure tank and supplies it to the spray nozzle. Thus, since the phosphor-containing liquid is supplied from the pressure tank to the spray nozzle by supplying air to the pressure tank, the phosphor-containing liquid can be stably supplied. That is, the supply amount of the phosphor-containing liquid does not fluctuate due to the pulsation of the pump as in the case where the phosphor-containing liquid is supplied from the pressure tank to the spray nozzle using a pump.

  In addition, the movement adjusting unit pushes out the phosphor-containing liquid from the pressure tank by supplying the air and moves it to the storage tank via the spray nozzle when spraying is not performed. Thereby, it can suppress that the fluorescent substance in a fluorescent substance containing liquid precipitates in the flow path (pipe) which connects a spray nozzle and each tank in a spray nozzle. Moreover, since the phosphor-containing liquid is moved by supplying air into the pressure tank and no circulation pump is used for the above movement, the diaphragm of the circulation pump is moved by the phosphor in the phosphor-containing liquid. The shavings (impurities) can be prevented from being mixed into the phosphor-containing liquid. As a result, in the light emitting element after the phosphor is applied, it is possible to suppress the occurrence of partial point defects due to the above-described impurities during light emission, and to reduce illuminance variation.

  In the phosphor coating apparatus of the present invention, the movement adjusting unit includes an air supply unit that supplies air into the pressure tank, and an air control valve that controls supply of air from the air supply unit to the pressure tank. A liquid supply control valve that controls supply of the phosphor-containing liquid from the storage tank to the pressure tank; and a liquid movement control valve that controls movement of the phosphor-containing liquid from the spray nozzle to the storage tank; And the movement adjusting unit closes both the liquid supply control valve and the liquid movement control valve at the time of spray injection and opens the air control valve by the air supply unit. While supplying air into the pressure tank, when the spray is not sprayed, the liquid supply control valve is closed, and the liquid movement control valve and the empty tank are closed. With open control valve, it may be supplied to the air in the interior of the pressure tank by the air supply unit.

  During spray injection, both the liquid supply control valve and the liquid movement control valve are closed and the air control valve is open. Therefore, air is supplied from the air supply unit to the pressure tank via the air control valve, and the pressure tank Thus, the phosphor-containing liquid can be reliably extruded from, and the extruded phosphor-containing liquid can be supplied only to the spray nozzle and sprayed. On the other hand, when the spray is not sprayed, the liquid supply control valve is closed and the liquid movement control valve and the air control valve are open, so air is supplied from the air supply unit to the pressure tank via the air control valve, The phosphor-containing liquid can be reliably pushed out of the tank, and the pushed-out phosphor-containing liquid can be moved to the storage tank via the spray nozzle and the liquid movement control valve.

  In the phosphor coating apparatus according to the present invention, the storage tank is located above the liquid surface of the phosphor-containing liquid in the pressure tank, and the movement adjusting unit is configured to perform the spray non-injection. The phosphor-containing liquid in the storage tank may be supplied to the pressure tank by switching the air control valve from the open state to the closed state and switching the liquid supply control valve from the closed state to the open state.

  In this case, the phosphor-containing liquid in the storage tank can be supplied (supplemented) to the pressure tank by its own weight.

  In the phosphor coating apparatus of the present invention, the air control valve is a three-way valve that, when in the closed state, stops supplying air from the air supply unit to the pressure tank and simultaneously releases air from the pressure tank to the outside. It may be comprised.

  In this configuration, when the air control valve is closed, the supply of air from the air supply unit to the pressure tank stops, and at the same time, the pressure tank immediately returns to atmospheric pressure. Thereby, the phosphor-containing liquid can be smoothly supplied (supplemented) from the storage tank to the pressure tank.

  The phosphor coating apparatus according to the present invention includes a spray instruction unit for instructing spraying by the spray nozzle and stopping thereof, and the liquid supply control valve and the liquid movement control valve based on an instruction from the spray instruction unit. And a valve control unit that controls opening and closing of the air control valve, and the valve control unit is configured to control the liquid supply control valve and the liquid movement when spraying is instructed by the spray instruction unit. While the control valve is closed and the air control valve is opened, when the spray instruction is instructed to stop spray injection, the liquid supply control valve is closed and the liquid movement control valve and the air control valve are opened. May be.

  Control of each valve of the valve control unit based on such an instruction from the spray instruction unit eliminates the need for the user to perform switching operation (opening / closing operation) of each valve between spray injection and non-spray injection.

  The phosphor coating apparatus of the present invention further includes a remaining amount detection sensor for detecting the remaining amount of the phosphor-containing liquid inside the pressure tank, and the valve control unit is configured to detect the remaining amount by the remaining amount detection sensor. When it is detected that the remaining amount of the phosphor-containing liquid is not more than a predetermined value, the air control valve may be closed and the liquid supply control valve may be opened.

  When the remaining amount detection sensor detects that the remaining amount of the phosphor-containing liquid in the pressure tank is less than or equal to the predetermined value, the air control valve is closed and the liquid supply control valve is opened. It is possible to automatically supply (replenish) the phosphor-containing liquid to the pressure tank.

  The phosphor coating device of the present invention further includes a stirring device for stirring the phosphor-containing liquid in the storage tank, and the stirring device is in non-contact with the inner surface of the storage tank. You may have the stirring member which is located in and stirs the said fluorescent substance containing liquid.

  Since the phosphor-containing liquid in the storage tank is agitated by the stirring device, it is possible to reduce the precipitation of the phosphor in the phosphor-containing liquid in the storage tank. Further, since the stirring member of the stirring device is provided so as not to be in contact with the inner surface of the storage tank, for example, by appropriately setting the distance between the stirring member and the inner wall of the storage tank, the stirring member and the storage member are stored. The phosphor in the phosphor-containing liquid located in the area sandwiched between the inner walls of the tank can prevent the inner surface of the storage tank or the stirring member from being scraped, and the shavings are mixed into the phosphor-containing liquid as impurities. Can be prevented.

  In the phosphor coating apparatus of the present invention, the storage tank may be formed of a transparent container.

  In this case, the state (stirring state) of the phosphor-containing liquid in the storage tank can be easily confirmed visually.

  In the phosphor coating apparatus of the present invention, the storage tank may be made of ceramic.

  In this configuration, when the phosphor-containing liquid is stirred in the storage tank, the inner surface of the storage tank is scraped by the phosphor in the phosphor-containing liquid, and the shavings are mixed as impurities into the phosphor-containing liquid. Can be suppressed.

  The phosphor coating apparatus of the present invention may further include an extruding unit that pushes the phosphor-containing liquid in the storage tank into the pressure tank by applying pressure to the air in the storage tank.

  In this case, even if the phosphor-containing liquid has a relatively high viscosity, the phosphor-containing liquid can be supplied by being pushed out from the storage tank to the pressure tank by the extrusion unit.

  The phosphor coating apparatus of the present invention may further include a flow rate adjusting valve that throttles the flow rate of the phosphor-containing liquid moving from the spray nozzle to the storage tank.

  When spray is not sprayed, the flow rate of the phosphor-containing liquid that moves from the spray nozzle to the storage tank can be suppressed to gently mix with the phosphor-containing liquid in the storage tank. Can be suppressed.

  The phosphor coating apparatus according to the present invention may further include an air supply amount adjustment valve that reduces an air supply amount to the pressure tank when the spray is not sprayed compared to when spraying.

  In this case, the amount of the phosphor-containing liquid pushed out of the pressure tank by the supply of air when spraying is not performed can be made smaller than when spraying. Thereby, the phosphor containing liquid which moves to a storage tank from a pressure tank via a spray nozzle at the time of spray non-injection is slowly mixed with the phosphor containing liquid in a storage tank. Therefore, foaming during mixing of the phosphor-containing liquid can be suppressed.

  In addition, since the amount of the phosphor-containing liquid is less when spraying from the pressure tank when spraying is not performed than when spraying, for example, the phosphor in the middle of the flow path from the pressure tank to the storage tank via the spray nozzle Compared with the configuration in which the flow rate of the contained liquid is reduced by the bulb, the phosphor contained in the phosphor-containing solution is not clogged in the bulb. Thereby, at the time of spray non-injection, the phosphor-containing liquid can be reliably moved from the pressure tank to the storage tank via the spray nozzle.

  According to the present invention, at the time of spray injection, the phosphor-containing liquid is supplied from the pressure tank to the spray nozzle by supplying air to the pressure tank, so that the fluorescence is generated by the pulsation of the pump as in the case of using the pump. The supply amount of the body-containing liquid does not fluctuate, and the phosphor-containing liquid can be stably supplied.

  In addition, since the phosphor-containing liquid is moved by supplying air to the pressure tank when the spray is not sprayed, the diaphragm of the circulation pump causes the fluorescence in the phosphor-containing liquid to flow as in the case of using a circulation pump. It is possible to prevent impurities from being mixed into the phosphor-containing liquid by being scraped by the body. As a result, in the light emitting element after the phosphor is applied, partial point defects at the time of light emission can be suppressed, and variation in illuminance can be reduced.

It is sectional drawing which shows the schematic structure of the light-emitting device produced with the fluorescent substance coating device which concerns on one Embodiment of this invention. It is explanatory drawing which shows the state which is spraying the fluorescent substance containing liquid toward LED of the said light-emitting device. It is explanatory drawing which shows the schematic structure of the said fluorescent substance coating device. It is a flowchart which shows the flow of operation | movement at the time of the spray injection in the said fluorescent substance coating device. It is a flowchart which shows the flow of operation | movement at the time of the spray non-injection in the said fluorescent substance coating device. It is a flowchart which shows the flow of the replenishment operation | movement of the said fluorescent substance containing liquid. It is explanatory drawing which shows the schematic structure of the fluorescent substance coating device of the comparative example 1. It is explanatory drawing which shows the schematic structure of the fluorescent substance coating device of the comparative example 2. It is another structure of the fluorescent substance coating device of embodiment of this invention, Comprising: It is a block diagram which shows the schematic structure of the principal part. It is explanatory drawing which shows other structure of the said fluorescent substance coating device. It is explanatory drawing which shows other structure of the said fluorescent substance coating device. It is explanatory drawing which shows other structure of the said fluorescent substance coating device. (A) And (b) is explanatory drawing which shows each the structural example of the air supply amount adjustment valve with which the fluorescent substance coating device of FIG. 12 is provided.

  An embodiment of the present invention will be described below with reference to the drawings. First, before describing the phosphor coating apparatus of the present embodiment, a light emitting device manufactured using the phosphor coating apparatus will be described.

(About light-emitting device)
FIG. 1 is a cross-sectional view illustrating a schematic configuration of the light-emitting device 1. The light emitting device 1 is configured by disposing an LED 3 as a light emitting element on an LED substrate 2 having a concave cross section. The LED 3 has a protruding electrode 3a on a surface facing the metal portion 4 on the LED substrate 2, and is connected to the metal portion 4 via the protruding electrode 3a (flip chip type). The light emitting device 1 may have a configuration in which only one LED 3 is provided for one LED substrate 2 or may have a configuration in which a plurality of LEDs 3 are provided.

  In the present embodiment, an LED element that emits blue light (hereinafter also referred to as a blue LED element) is used as the LED 3. The blue LED element is configured, for example, by stacking an n-GaN-based cladding layer, an InGaN light-emitting layer, a p-GaN-based cladding layer, and a transparent electrode on a sapphire substrate.

  Moreover, the phosphor layer 5 is formed inside the concave portion of the LED substrate 2 so as to cover the surface (including the light emitting surface and the side surface) of the LED 3. The phosphor layer 5 includes a phosphor that is excited by blue light emitted from the LED 3 and emits light having a wavelength different from that of the blue light (for example, yellow light). Accordingly, white light can be obtained by mixing the blue light emitted from the LED 3 and the yellow light emitted when the phosphor receives the blue light and emits secondary light, and the light emitting device 1 can be obtained as a white light source. Can be used as

  In forming the phosphor layer 5 on the surface of the LED 3, as shown in FIG. 2, the LED substrate 2 is supported from the back side by the support member 11 of the phosphor coating device 10 so that the LED 3 faces downward. Then, the spray nozzle 12 is disposed below the LED 3, and the phosphor-containing liquid (first liquid) is sprayed upward from the spray nozzle 12. Thereafter, a mixed liquid (second liquid) obtained by mixing the organometallic compound and the organic solvent is further applied from above the sprayed phosphor-containing liquid, fired, and hardened. Thereby, the fluorescent substance layer 5 is formed in the surface of LED3, and the light-emitting device 1 is completed.

(About phosphor-containing liquid and mixed liquid)
Next, details of the phosphor-containing liquid and the mixed liquid will be described.

  The phosphor-containing liquid as the first liquid contains a phosphor, a layered silicate mineral, and inorganic fine particles.

  The phosphor is excited by the light emitted from the LED 3 and emits fluorescence having a wavelength different from the wavelength of the emitted light. In the present embodiment, the blue light emitted from the blue LED element (wavelength 420 nm to 485 nm) is made of a YAG (yttrium, aluminum, garnet) phosphor that converts yellow light (wavelength 550 nm to 650 nm). Note that the phosphor is not limited to the YAG phosphor described above, and other phosphors such as a non-garnet phosphor that does not contain Ce can also be used.

  The layered silicate mineral is composed of a swellable clay mineral having a structure such as a mica structure, a kaolinite structure, or a smectite structure.

  The inorganic fine particles are composed of oxide fine particles such as silicon oxide, titanium oxide and zinc oxide, fluoride fine particles such as magnesium fluoride, and the like. The inorganic fine particles have a filling effect that fills the gap formed at the interface between the organometallic compound in the second liquid and the phosphor and the layered silicate mineral in the first liquid, and the coating liquid before heating (first liquid + second liquid ) To increase the viscosity, and provide a film strengthening effect to improve the film strength of the ceramic layer after heating. When a silicon-containing organic compound such as polysiloxane is used as the organometallic compound in the second liquid, it is preferable to use silicon oxide fine particles as the inorganic fine particles from the viewpoint of stability with respect to the formed ceramic layer.

  The first liquid further contains an organic solvent and water. As the organic solvent, it is preferable to use alcohols such as methanol, ethanol, propanol, butanol, and isopropyl alcohol (IPA) that are excellent in compatibility with the added water. When water is contained in the first liquid, water enters between the layers of the layered silicate mineral and the viscosity of the first liquid increases, so that sedimentation of the phosphor can be suppressed. In addition, since there exists a possibility of inhibiting a polymerization reaction when the impurity is contained in water, it is necessary to make the water to add the pure water which does not contain an impurity.

  As described above, the mixed liquid as the second liquid is configured by mixing an organometallic compound and an organic solvent.

  The organometallic compound serves as a binder for sealing the first liquid phosphor, the layered silicate mineral, and the inorganic fine particles. Examples of the organometallic compound used in the present embodiment include metal alkoxides, metal acetylacetonates, metal carboxylates, and the like. In particular, it is preferable to use metal alkoxides that are easily gelled by hydrolysis and polymerization reaction. Further, the metal alkoxide may be a single molecule such as tetraethoxysilane, or may be a polysiloxane in which an organic siloxane compound is linked in a chain or cyclic form, but the latter polysiloxane is preferable in terms of increasing viscosity. .

  In addition, although there is no restriction | limiting in particular in the kind of metal contained in an organometallic compound, from a viewpoint of the stability of the fluorescent substance layer 5 to be formed, and the ease of manufacture, the organometallic compound may contain silicon. preferable. The organometallic compound may contain a plurality of types of metals.

  As the organic solvent of the second liquid, like the organic solvent of the first liquid, it is preferable to use alcohols such as methanol, ethanol, propanol, butanol, and isopropyl alcohol (IPA) having excellent compatibility with water.

  After the phosphor-containing liquid as the first liquid is spray-coated, the liquid mixture as the second liquid is spray-coated, heated and baked to obtain a light-transmitting ceramic layer as the phosphor layer 5 of the light-emitting device 1. be able to.

(About phosphor coating device)
Next, a phosphor coating apparatus that sprays the above-described phosphor-containing liquid and coats it on the LED surface will be described. FIG. 3 is an explanatory diagram showing a schematic configuration of the phosphor coating apparatus 10. The phosphor coating apparatus 10 includes a support member 11, a spray nozzle 12, and a liquid supply unit 13. As described above, the support member 11 supports the application target.

  The spray nozzle 12 sprays the phosphor-containing liquid on the surface of the LED 3, and has a needle 12a for opening and closing the nozzle. That is, by moving the needle 12a closing the nozzle back and forth, the gap between the nozzles can be opened and closed, and spray injection can be turned ON / OFF.

  The liquid supply unit 13 supplies the phosphor-containing liquid to the spray nozzle 12, and includes a storage tank 14, a pressure tank 15, a stirring device 16, a remaining amount detection sensor 17, and a movement adjustment unit 18. doing. The spray nozzle 12, the storage tank 14, and the pressure tank 15 are connected to each other by piping.

  The storage tank 14 is a tank that stores the phosphor-containing liquid, and is always located above the liquid surface (upper surface) of the phosphor-containing liquid in the pressure tank 15. The pressure tank 15 receives the phosphor-containing liquid supplied to the spray nozzle 12 from the storage tank 14. By dividing the tank holding the phosphor-containing liquid into a storage tank 14 and a pressure tank 15 as in the present embodiment, by supplying air to the pressure tank 15 as described later, the spray nozzle 12 It is possible to achieve spray injection of the phosphor-containing liquid and movement (circulation) of the phosphor-containing liquid when spraying is not performed.

  In the present embodiment, the storage tank 14 is composed of a transparent container. Such a transparent container can be composed of, for example, a transparent resin, transparent glass, or transparent ceramic. Thus, when the storage tank 14 is transparent, the state of the phosphor-containing liquid in the storage tank 14 (the stirring state by the stirring device 16) can be easily confirmed visually.

  The storage tank 14 can be formed of a transparent container because the storage tank 14 is provided separately from the pressure tank 15. That is, the pressure tank 15 is required to have pressure resistance because it is pressurized by the supply of air from an air supply unit 19 to be described later, but the storage tank 14 is not subjected to such pressure, but has pressure resistance. Is not required, the storage tank 14 can be formed of a transparent container.

  Moreover, the storage tank 14 may be comprised with the ceramic. The ceramic at this time may be a transparent ceramic or an opaque ceramic. However, in terms that the phosphor-containing liquid in the storage tank 14 can be visually confirmed, it may be the former transparent ceramic. desirable.

  As described above, since the storage tank 14 is made of ceramic, when the phosphor-containing liquid in the storage tank 14 is stirred by the stirring device 16, the inner surface of the storage tank 14 is scraped by the phosphor in the phosphor-containing liquid. As a result, it is possible to suppress the scrap from being mixed into the phosphor-containing liquid as an impurity.

  The stirring device 16 stirs the phosphor-containing liquid in the storage tank 14, and includes, for example, a stirring member 16a having a plurality of blades such as a propeller, and a drive unit 16b for driving the stirring member 16a. It is configured. The agitating member 16a is located in the storage tank 14 so as not to be in contact with the inner surface of the storage tank 14, and is agitated with the phosphor-containing liquid by being driven to rotate by the drive unit 16b.

  Thus, since the phosphor-containing liquid in the storage tank 14 is agitated by the stirring device 16, it is possible to reduce the precipitation of the phosphor in the phosphor-containing liquid in the storage tank 14. In addition, since the stirring member 16a is provided so as not to contact the inner surface of the storage tank 14, the stirring member 16a and the stirring member 16a can be provided as long as the distance between the stirring member 16a and the inner wall of the storage tank 14 is appropriately set. The phosphor in the phosphor-containing liquid located in the region sandwiched between the inner walls of the storage tank 14 serves as an abrasive, and the inner surface of the storage tank 14 or the stirring member 16a is shaved. Mixing into the liquid can be prevented.

  The remaining amount detection sensor 17 detects the remaining amount of the phosphor-containing liquid inside the pressure tank 15. Such a remaining amount detection sensor 17 can be configured by a known liquid level detection sensor such as an optical method, an ultrasonic method, a capacitance method, or a float method.

  By the way, the optical system is based on the intensity of the reflected light at the time of irradiating the liquid surface with light (laser) and detecting the reflected light and the time from when the laser is irradiated until the reflected light is detected. In this method, the distance to the liquid surface is measured. The ultrasonic method is a method in which a reflected wave of an ultrasonic wave emitted to the liquid surface is detected, and the distance to the liquid surface is measured based on the intensity of the reflected wave and the time until the reflected wave is detected. The electrostatic capacity method is a method of measuring the position of the liquid surface by detecting an electrical change in the detection position. With the float type, a magnet is built in the float that follows the liquid level, and a reed switch is provided on the stem at the position where the liquid level is to be detected. This is a method of detecting the position of the liquid level by outputting an ON signal when entering the inside and outputting an OFF signal when outside the magnetic field.

  Any type of liquid level detection sensor can detect the position of the liquid level of the phosphor-containing liquid in the pressure tank 15, thereby detecting the remaining amount of the phosphor-containing liquid in the pressure tank 15. be able to. In FIG. 3, as an example, a case where the remaining amount detection sensor 17 is configured by a capacitive liquid level detection sensor is illustrated.

  When the remaining amount of the phosphor-containing liquid detected by the remaining amount detection sensor 17 is equal to or less than a predetermined value, a notification unit (not shown) notifies the user. In addition, the alerting | reporting part can be comprised by a display part or an audio | voice output part, for example. That is, it is possible to notify the user that the remaining amount is equal to or less than a predetermined value by displaying on the display unit that the remaining amount is low or by performing audio output (buzzer sounding) from the audio output unit.

  The movement adjusting unit 18 supplies air to the inside of the pressure tank 15 to push out the phosphor-containing liquid inside the pressure tank 15 and adjust the movement of the phosphor-containing liquid. The unit 19 includes an air control valve V1, a liquid supply control valve V2, and a liquid movement control valve V3.

  The air supply unit 19 supplies air into the pressure tank 15 and is connected to the pressure tank 15 through a pipe. The air supply unit 19 may be configured by a compressor that compresses air and supplies the compressed air to the inside of the pressure tank 15.

  The air control valve V <b> 1 is a valve that controls the supply of air from the air supply unit 19 to the pressure tank 15. The liquid supply control valve V <b> 2 is a valve that controls the supply of the phosphor-containing liquid from the storage tank 14 to the pressure tank 15. The liquid movement control valve V3 is a valve that controls the movement of the phosphor-containing liquid from the spray nozzle 12 to the storage tank 14. These valves can be opened and closed manually or automatically. An example of automatic control will be described later.

(Operation of phosphor coating device)
Next, the operation of the phosphor coating apparatus 10 having the above configuration will be described. The operation of the phosphor coating apparatus 10 is roughly divided into an operation at the time of spraying by the spray nozzle 12 and an operation at the time of non-spraying. Hereinafter, each operation will be described in order. In the following description, the determination of the remaining amount of the phosphor-containing liquid in the pressure tank 15 is based on the detection result of the remaining amount detection sensor 17.

<When spraying>
FIG. 4 is a flowchart showing a flow of operations at the time of spray injection in the phosphor coating apparatus 10. First, the phosphor-containing liquid is replenished from the storage tank 14 to the pressure tank 15 (S1). The details of this replenishment operation will be described later. If the remaining amount of the phosphor-containing liquid in the pressure tank 15 is equal to or greater than a predetermined value, the step S1 can be omitted.

  Next, with the liquid movement control valve V3 and the liquid supply control valve V2 closed (S2, S3) and the air control valve V1 opened (S4), the pressure tank 15 is supplied from the air supply unit 19 via the air control valve V1. Air is supplied into the interior (S5). The air pressure in the pressure tank 15 at this time is, for example, 0.1 to 0.5 MPa.

  Then, the spray nozzle 12 is opened (S6). Thereby, by supplying air from the air supply unit 19, the phosphor-containing liquid is pushed out from the pressure tank 15, supplied to the spray nozzle 12, and sprayed from the spray nozzle 12 toward the application target (LED 3). As a result, the phosphor is applied in a dispersed state on the surface of the LED 3.

  Until the spray injection is completed, the extrusion of the phosphor-containing liquid from the pressure tank 15 by the supply of air is continued (No in S7). When the spray injection is to be ended (Yes in S7), the spray nozzle 12 is closed (S8). Thereby, spray injection is complete | finished and it starts the operation | movement at the time of the next spray non-injection.

<When spray is not sprayed>
FIG. 5 is a flowchart showing a flow of operations in the phosphor coating apparatus 10 when spraying is not performed. First, the liquid movement control valve V3 that was closed at the time of spray injection is opened (S11). Then, the liquid supply control valve V2 is kept closed (S12), and the air control valve V1 is kept open (S13).

  In this state, air is supplied from the air supply unit 19 to the inside of the pressure tank 15 via the air control valve V1 (S14). The air pressure in the pressure tank 15 at this time is, for example, 0.1 to 0.5 MPa. At this time, since the nozzle of the spray nozzle 12 is closed and the liquid movement control valve V3 is open, the phosphor-containing liquid in the pressure tank 15 is supplied from the air supply unit 19 to the pressure tank 15. Is pushed through the spray nozzle 12 and moved to the storage tank via the liquid movement control valve V3.

  When the phosphor-containing liquid is transferred from the pressure tank 15 to the storage tank 14 via the spray nozzle 12 as described above, when the spray liquid is transferred (Yes in S15), this flow is finished. The operation at the time of spray injection indicated by 4 is started. On the other hand, in the case of No in S15, that is, when the movement of the phosphor-containing liquid is not continued in S15 and the movement of the phosphor-containing liquid is continued, the remaining amount of the phosphor-containing liquid in the pressure tank 15 is not more than a predetermined value. If (Yes in S16), the replenishment operation of the phosphor-containing liquid is performed (S17). Note that the replenishment operation at this time is the same as S1 in FIG. 4, and details thereof will be described later. On the other hand, in the case of No in S16, that is, if the remaining amount of the phosphor-containing liquid in the pressure tank 15 exceeds a predetermined value, the processes after S14 are repeated.

  When the process proceeds to the spray injection after S17 (Yes in S18), this flow is finished and the operation at the time of the spray injection shown in FIG. 4 is started. On the other hand, in the case of No in S18, the air control valve V1 is closed and the liquid supply control valve V2 is opened by the above-described replenishment operation. Therefore, the process proceeds to S12, and the operations after S12 are repeated.

<Liquid replenishment operation>
Next, the replenishment operation of the phosphor-containing liquid to the pressure tank 15 in S1 during spray injection and S17 during non-spray injection will be described. FIG. 6 is a flowchart showing the flow of the replenishment operation of the phosphor-containing liquid.

  First, the air control valve V1 is closed, and the supply of air to the pressure tank 15 by the air supply unit 19 is stopped (S21). In this state, the liquid supply control valve V2 is opened (S22). Thereby, in exchange for the air in the pressure tank 15 moving to the storage tank 14 via the liquid supply control valve V2, the phosphor-containing liquid is transferred from the storage tank 14 to the pressure tank 15 via the liquid supply control valve V2. It moves and the pressure tank 15 is replenished with the phosphor-containing liquid (S23). At this time, as described above, since the storage tank 14 is always located above the liquid level of the phosphor-containing liquid in the pressure tank 15, the phosphor-containing liquid is transferred from the storage tank 14 to the pressure tank 15. Move with its own weight.

  When the spray is not sprayed, the phosphor-containing liquid pushed out of the pressure tank 15 and moved to the storage tank 14 via the spray nozzle 12 eventually returns to the pressure tank 15 and circulates in the apparatus. Will be the same.

  The replenishment of the phosphor-containing liquid is performed until the remaining amount of the phosphor-containing liquid in the pressure tank 15 exceeds a predetermined value (No in S24). When the remaining amount of the phosphor-containing liquid in the pressure tank 15 exceeds a predetermined value (Yes in S24), the liquid supply control valve V2 is closed and the replenishment of the phosphor-containing liquid from the storage tank 14 to the pressure tank 15 is ended. (S25).

(About effect)
As described above, in this embodiment, at the time of spray injection, air is supplied into the pressure tank 15 to push out the phosphor-containing liquid inside the pressure tank 15 and supply it to the spray nozzle 12. On the other hand, when spraying is not performed, the phosphor-containing liquid is pushed out from the pressure tank 15 by the supply of the air and is moved to the storage tank 14 via the spray nozzle 12.

  Thus, by supplying the phosphor-containing liquid from the pressure tank 15 to the spray nozzle 12 by spraying air to the pressure tank 15 during spray injection, the phosphor-containing liquid is applied to the nozzle using a pump. The supply amount of the phosphor-containing liquid does not fluctuate due to the pulsation of the pump as in the case of supplying the liquid. As a result, the phosphor-containing liquid can be stably supplied to the spray nozzle 12, and the phosphor-containing liquid can be uniformly applied to the surface of the LED 3.

  At the time of spray injection, both the liquid supply control valve V2 and the liquid movement control valve V3 are closed and the air control valve V1 is open. The phosphor-containing liquid can be reliably pushed out from the pressure tank 15 by supplying air, and the pushed-out phosphor-containing liquid can be supplied only to the spray nozzle 12 and sprayed.

  On the other hand, at the time of spray non-injection, the phosphor-containing liquid is pushed out from the pressure tank 15 by supplying air to the pressure tank 15 and moved to the storage tank 14 via the spray nozzle 12. Precipitation of the phosphor in the phosphor-containing liquid can be suppressed. Moreover, since the phosphor-containing liquid is moved by supplying air into the pressure tank 15, the diaphragm of the circulation pump is used to move the phosphor-containing liquid as in the case where the phosphor-containing liquid is moved using a circulation pump. It is not scraped off by the phosphor inside, and it is possible to prevent scraps (impurities) from being mixed into the phosphor-containing liquid. As a result, in the LED 3 after the phosphor is applied, it is possible to suppress the occurrence of partial point defects due to the above-described impurities during light emission, and to reduce illuminance variation.

  Further, when the spray is not ejected, since the liquid supply control valve V2 is closed and the liquid movement control valve V3 and the air control valve V1 are open, the air supply unit 19 supplies air to the pressure tank 15 via the air control valve V1. And the phosphor-containing liquid can be reliably pushed out from the pressure tank 15, and the pushed-out phosphor-containing liquid is moved to the storage tank 14 via the spray nozzle 12 and the liquid movement control valve V3. Can do.

  Further, when the spray is not sprayed, the phosphor-containing liquid moves from the pressure tank 15 to the storage tank 14 via the spray nozzle 12 and the liquid movement control valve V3, so that the amount of the phosphor-containing liquid in the pressure tank 15 is increased. Gradually decreases. However, the storage tank 14 is located above the liquid level of the phosphor-containing liquid in the pressure tank 15, and when the spray is not sprayed, the air control valve V1 is switched from the open state to the closed state to control liquid supply. By switching the valve V2 from the closed state to the open state, the phosphor-containing liquid in the storage tank 14 can be replenished to the pressure tank 15 by its own weight.

  By the way, the air control valve V1 described above is a three-way valve that, when closed, stops the supply of air from the air supply unit 19 to the pressure tank 15 and simultaneously releases the air in the pressure tank 15 to the outside. It is desirable. In this case, the air control valve V1 serves as an air vent that draws out air from the pressure tank 15, stops the supply of air from the air supply unit 19 to the pressure tank 15, and at the same time, the pressure tank 15 immediately reaches atmospheric pressure. Return to. Thereby, the phosphor-containing liquid can be smoothly supplied (supplemented) from the storage tank 14 to the pressure tank 15.

  That is, for example, when the air control valve V1 is not a three-way valve, if residual pressure remains in the pressure tank 15, the residual pressure and the pressure due to the weight of the phosphor-containing liquid are pressed against each other, and the pressure tank 15, the phosphor-containing liquid may not move smoothly. On the other hand, when the air control valve V1 is constituted by a three-way valve, when the supply of air from the air supply unit 19 to the pressure tank 15 is stopped, the residual pressure is reset and the storage tank 14 As the phosphor-containing liquid enters the pressure tank 15, the air in the pressure tank 15 escapes from the exhaust port of the three-way valve, so that the phosphor-containing liquid can be smoothly supplied from the storage tank 14 to the pressure tank 15. .

(About point defect evaluation)
Next, evaluation of point defects of the LED 3 after the phosphor is applied will be described. Evaluation of this point defect was performed as follows. First, in the phosphor coating apparatus 10 of the present embodiment described above, the phosphor-containing liquid in the pressure tank 15 is moved and circulated for a predetermined time (for example, 1 hour) in a non-spraying state, and then the LED 3 is sprayed to spray. A phosphor-containing liquid (first liquid) was applied to the surface, and then a mixed liquid (second liquid) was applied to form a phosphor layer 5 to complete the light emitting device 1 that emits white light. Then, the light emitting device 1 was turned on to illuminate the blackboard 3 m ahead, and it was visually confirmed whether or not a point defect (in this case, a black spot) occurred in the illumination area of the blackboard. Such point defects were confirmed for each of the 100 light emitting devices 1 manufactured under the same conditions, and the defect rate was calculated. The defect rate (%) at this time was calculated by ((number of light-emitting devices in which point defects were confirmed) / (number of all light-emitting devices)) × 100.

  Further, for comparison with the present embodiment, a light emitting device was manufactured under the same conditions as described above using the phosphor coating apparatuses 100 and 200 of Comparative Examples 1 and 2, and the same evaluation as described above was performed. The composition of the phosphor-containing liquid in the initial state was the same in this embodiment and Comparative Examples 1 and 2.

  In addition, the structure of the fluorescent substance coating device 100 * 200 of the comparative examples 1 and 2 is as follows. FIG. 7 is an explanatory diagram illustrating a schematic configuration of the phosphor coating apparatus 100 of the first comparative example. The phosphor coating apparatus 100 includes a tank 101 that contains a phosphor-containing liquid, a spray nozzle 102, a circulation pump 103, and a valve 104. The tank 101 and the spray nozzle 102 are connected by two pipes arranged in parallel. The circulation pump 103 is located on one pipe, and the valve 104 is located on the other pipe.

  In this configuration, when spraying by the spray nozzle 102, the phosphor-containing liquid in the tank 101 is supplied to the spray nozzle 102 by operating the circulation pump 103 with the valve 104 closed. Therefore, when the spray nozzle 102 is opened, the phosphor-containing liquid is sprayed from the spray nozzle 102 toward the application target.

  At the time of non-spraying, the circulation pump 103 is operated with the valve 104 open, whereby the phosphor-containing liquid in the tank 101 moves to the tank 101 via the spray nozzle 102 and the valve 104 and circulates.

  As described above, the phosphor coating apparatus 100 of Comparative Example 1 supplies the phosphor-containing liquid from the tank 101 to the spray nozzle 102 at the time of spray injection, and moves and circulates the phosphor-containing liquid at the time of non-spraying. Both are configured by the circulation pump 103.

  On the other hand, FIG. 8 is an explanatory diagram showing a schematic configuration of the phosphor coating apparatus 200 of Comparative Example 2. The phosphor coating apparatus 200 includes a tank 201 that contains a phosphor-containing liquid, a spray nozzle 202, an air supply unit 203, a first valve 204, a circulation pump 205, and a second valve 206. Yes. The tank 201 and the spray nozzle 202 are connected by two pipes arranged in parallel. The air supply unit 203 supplies air to the inside of the tank 201 via the first valve 204 on a different path from the two pipes. The circulation pump 205 and the second valve 206 are provided in one of the two pipes.

  In this configuration, when spraying by the spray nozzle 202, the first valve 204 is opened with the second valve 206 closed, and air is supplied from the air supply unit 203 into the tank 201 via the first valve 204. Supply. Thereby, the phosphor-containing liquid in the tank 201 is supplied to the spray nozzle 202, and the phosphor-containing liquid is sprayed from the spray nozzle 202 toward the application target by opening the spray nozzle 202.

  When spraying is not performed, the circulation pump 205 is operated while the first valve 204 is closed and the second valve 206 is opened, whereby the phosphor-containing liquid in the tank 201 is sprayed with the spray nozzle 202 and the second valve. It moves to the tank 201 via 206 and circulates. The direction of circulation of the phosphor-containing liquid by the circulation pump 205 may be opposite to the above.

  Thus, the phosphor coating apparatus 200 of Comparative Example 2 supplies the phosphor-containing liquid from the tank 201 to the spray nozzle 202 during spray injection by supplying air from the air supply unit 201 to the tank 201. In this configuration, the circulating pump 205 moves and circulates the phosphor-containing liquid when spraying is not performed.

  Table 1 shows the results of evaluation of point defects when the phosphor coating apparatus 10 of the present embodiment and the phosphor coating apparatuses 100 and 200 of Comparative Examples 1 and 2 are used.

  From Table 1, when the phosphor coating apparatuses 100 and 200 of Comparative Examples 1 and 2 are used, the defect rates are 10% or more and 1% or more and less than 10%, respectively, but the phosphor coating apparatus 10 of the present embodiment. The defect rate was less than 1%. From this, it can be said that the point defect of the light-emitting device 1 can be remarkably suppressed by using the phosphor coating apparatus 10 of the present embodiment. In this embodiment, the phosphor-containing liquid is moved by supplying air into the pressure tank 15 when spraying is not performed, and no circulation pump is used as in Comparative Examples 1 and 2. Therefore, it is considered that the diaphragm of the circulation pump is not scraped by the phosphor, and the scrap is not mixed into the phosphor-containing liquid.

(Other configurations of phosphor coating device)
FIG. 9 is a block diagram showing another configuration of the phosphor coating apparatus 10 of the present embodiment and showing a schematic configuration of a main part. The phosphor coating apparatus 10 may be configured to automatically open and close the above-described valves. Such a phosphor coating apparatus 10 is configured to further include a spray instruction unit 20 and a valve control unit 21 in addition to the above-described configuration.

  The spray instruction unit 20 is an instruction unit for instructing spray injection by the spray nozzle 12 and its stop. This spray instruction | indication part 20 can be comprised with the switch which the user of an apparatus switches spray injection and its stop manually, for example. In addition, such a switch may be provided in the spray gun which has the spray nozzle 12, and may be provided in places other than a spray gun.

  Further, the spray instruction unit 20 can also be configured by a sensor that detects that the application target is conveyed above the spray nozzle 12 by the support member 11. For example, when the sensor detects that the application target has been transported above the spray nozzle 12, it outputs a signal instructing spray injection, and the application target is transported and deviated from above the spray nozzle 12. When this is detected, the above-described sensor can be used as the spray instruction unit 20 by outputting a signal instructing the stop of spray injection.

  The valve control unit 21 controls the opening and closing of the liquid supply control valve V2, the liquid movement control valve V3, and the air control valve V1 based on the instruction from the spray instruction unit 20, and the air supply unit 19 supplies the pressure tank 15 to the pressure tank 15. It controls the supply of air and is composed of a central processing unit such as a CPU.

  The valve control unit 21 closes the liquid movement control valve V3 and the liquid supply control valve V2 and opens the air control valve V1 when spraying is instructed by the spray instruction unit 20 (corresponding to S2 to S4 in FIG. 4). ). On the other hand, the valve control unit 21 closes the liquid supply control valve V2 and opens the liquid movement control valve V3 and the air control valve V1 when the spray instructing unit 20 instructs to stop spray injection (S11 in FIG. 5). To S13).

  By controlling each valve of the valve control unit 21 based on an instruction from the spray instruction unit 20 as described above, air is supplied into the pressure tank 15 via the air control valve V1 at the time of spray injection. From this, the phosphor-containing liquid can be extruded and supplied to the spray nozzle 12. On the other hand, when spray is not ejected, air is supplied into the pressure tank 15 via the air control valve V1, and the phosphor-containing liquid is pushed out from the pressure tank 15 and stored via the spray nozzle 12 and the liquid movement control valve V3. It can be moved to the tank 14. Therefore, it is not necessary for the user to perform a switching operation (opening / closing operation) of each valve between spray injection and non-spray injection.

  When the remaining amount detection sensor 17 detects that the remaining amount of the phosphor-containing liquid in the pressure tank 15 is equal to or less than a predetermined value, the valve control unit 21 closes the air control valve V1 and supplies the liquid. The control valve V2 may be opened.

  For example, in the state where the liquid movement control valve V3 is opened and the phosphor-containing liquid is moving toward the storage tank 14 at the time of non-spraying, the remaining amount detection sensor 17 detects the phosphor-containing liquid in the pressure tank 15. When it is detected that the remaining amount is less than or equal to the predetermined value, the air control valve V1 is closed (pushing out the phosphor-containing liquid from the pressure tank by supplying air) and the liquid supply control valve V2 is opened. Accordingly, the supply (replenishment) of the phosphor-containing liquid from the storage tank 14 to the pressure tank 15 can be automatically performed, and the shortage of the remaining amount of the phosphor-containing liquid in the pressure tank 15 is automatically resolved. Can do.

  As described above, the flow shown in FIGS. 4 to 6 can be automatically controlled by the control by the valve control unit 21 as described above (control of opening and closing of each valve during spray injection and non-spray injection).

(Still another configuration of the phosphor coating apparatus)
FIG. 10 is an explanatory diagram showing still another configuration of the phosphor coating apparatus 10. As shown in the figure, the phosphor coating apparatus 10 may further include an extruding unit 22. The extrusion unit 22 applies the pressure to the air in the storage tank 14 when supplying (replenishing) the phosphor-containing liquid from the storage tank 14 to the pressure tank 15, so that the phosphor-containing liquid in the storage tank 14. To the pressure tank 15. The pushing portion 22 is formed of, for example, a piston that is provided at an upper portion of the storage tank 14 and supplies air to the inside of the storage tank 14.

  The air supply unit 19 described above does not supply air to the pressure tank 15 when the phosphor-containing liquid is replenished to the pressure tank 15 (because the air control valve V1 is closed). If the piping is devised so that air is supplied from the portion 19 to the inside of the storage tank 14, the air supply portion 19 can also serve as the extrusion portion 22.

  By providing the extrusion part 22 as described above, even when the phosphor-containing liquid has a relatively high viscosity when the phosphor-containing liquid is replenished from the storage tank 14 to the pressure tank 15, the phosphor The contained liquid can be pushed out from the storage tank 14 by the extruding unit 22 and reliably supplied to the pressure tank 15. Further, since the range of the viscosity of the phosphor-containing liquid to be used is widened, variations in the composition of the phosphor-containing liquid are also increased.

  FIG. 11 is an explanatory view showing still another configuration of the phosphor coating apparatus 10. As shown in the figure, the phosphor coating apparatus 10 may further include a flow rate adjusting valve 23. The flow rate adjusting valve 23 functions as a flow rate restrictor for reducing the flow rate of the phosphor-containing liquid moving from the spray nozzle 12 to the storage tank 14.

  In this configuration, the phosphor-containing liquid that moves from the spray nozzle 12 to the storage tank 14 is reduced in the phosphor-containing liquid in the storage tank 14 by reducing the flow rate of the phosphor-containing liquid by the flow rate adjusting valve 23 when spraying is not performed. Is mixed little by little. Thereby, foaming at the time of mixing of the phosphor-containing liquid in the storage tank 14 can be suppressed, and preparation for the next supply from the storage tank 14 to the pressure tank 15 can be made.

  FIG. 12 is an explanatory diagram showing still another configuration of the phosphor coating apparatus 10. As shown in the figure, the phosphor coating apparatus 10 may further include an air supply amount adjustment valve 24. The air supply amount adjusting valve 24 is a valve for reducing the amount of air supplied to the pressure tank 15 when spraying is not performed compared to when spraying.

  Here, FIGS. 13A and 13B show configuration examples of the air supply amount adjusting valve 24, respectively. As shown in FIG. 5A, when the air flow path from the air supply unit 19 to the pressure tank 15 is configured by one, the air supply amount adjustment valve 24 is provided in a single flow path. The amount of air supplied to the pressure tank 15 may be changed between spray injection and non-spray injection by moving the needle 24a.

  In addition, as shown in FIG. 4B, when the air flow path from the air supply unit 19 to the pressure tank 15 is configured by two flow paths L1 and L2 having different flow rates, The air supply amount adjusting valve 24 changes the air supply amount to the pressure tank 15 between spray injection and non-spray injection by switching the air flow direction between the flow paths L1 and L2 by the directional valve 25. You may let them. For example, it is good also as a structure which suppresses the flow volume of air by switching to the flow path L2 by the direction valve 25 at the time of spray non-injection.

  Thus, by providing the air supply amount adjusting valve 24, the air supply amount to the pressure tank 15 at the time of spray non-injection is smaller than that at the time of spray injection, so that the air supply is pushed out of the pressure tank 15. The amount of the phosphor-containing liquid to be produced can be made smaller than that during spraying. Thereby, the phosphor containing liquid which moves to the storage tank 14 from the pressure tank 15 via the spray nozzle 12 at the time of spray non-injection is slowly mixed with the phosphor containing liquid in the storage tank 14. Therefore, foaming at the time of mixing the phosphor-containing liquid can be suppressed, and the next supply from the storage tank 14 to the pressure tank 15 can be immediately prepared.

  Moreover, in the structure which restrict | squeezes the flow volume of fluorescent substance containing liquid in the middle of the movement of fluorescent substance containing liquid with the flow volume adjusting valve 23 mentioned above, depending on the throttling condition, the fluorescent substance containing liquid is reduced by restrict | squeezing the internal diameter of the flow volume adjusting valve 23. It is also assumed that the phosphor contained in is clogged in the flow rate adjusting valve 23.

  In this regard, by providing the air supply amount adjusting valve 24 as described above, the amount of the phosphor-containing liquid becomes smaller than that during spray injection when it is pushed out from the pressure tank 15 when spray is not sprayed. This prevents the phosphor contained in the phosphor-containing liquid from being clogged in the bulb as in the configuration in which the flow rate of the phosphor-containing liquid is reduced during the movement by the bulb. As a result, the phosphor-containing liquid can be reliably moved from the pressure tank 15 to the storage tank 14 via the spray nozzle 12 when spraying is not performed.

(Other)
In the phosphor coating apparatus 10 of the present embodiment described above, the storage tank 14 and the pressure tank are used rather than the spray nozzle 12 and the surrounding pipes in order to prevent the backflow of the phosphor-containing liquid in the pipes that occurs when the valves are switched. It is desirable to arrange 15 at a high position.

  In the present embodiment, the phosphor-containing liquid is a liquid containing a phosphor that is excited by blue light and emits yellow fluorescence. However, the phosphor-containing liquid is not limited to such a phosphor-containing liquid. The phosphor coating apparatus 10 of the present embodiment can be applied as long as it is a phosphor-containing liquid that includes a phosphor that is excited by the emitted light of the LED and emits fluorescence having a color (wavelength) different from that of the emitted light.

  In the present embodiment, the phosphor-containing liquid as the first liquid and the mixed liquid as the second liquid are separated, and the first liquid is sprayed by the phosphor coating apparatus 10. You may make it spray-spray in the state which mixed 2nd liquid. However, in this case, since the solution is gelled by mixing the first liquid and the second liquid, it is desirable to use up the solution by spraying immediately after mixing.

  The phosphor coating device of the present invention can be used, for example, when a phosphor layer is formed by spraying a phosphor-containing liquid on the surface of a blue LED to manufacture a light emitting device that emits white light.

3 LED (light emitting element)
DESCRIPTION OF SYMBOLS 10 Fluorescent substance coating device 12 Spray nozzle 14 Storage tank 15 Pressure tank 16 Stirring device 16a Stirring member 17 Residual amount detection sensor 18 Movement adjustment part 19 Air supply part 20 Spray instruction | indication part 21 Valve control part 22 Extrusion part 23 Flow control valve 24 Air Supply amount adjustment valve V1 Air control valve V2 Liquid supply control valve V3 Liquid movement control valve

Claims (12)

A phosphor coating apparatus including a spray nozzle that sprays a phosphor-containing liquid on the surface of a light emitting element,
A storage tank for storing the phosphor-containing liquid;
A pressure tank that receives the phosphor-containing liquid supplied to the spray nozzle from the storage tank;
A movement adjusting unit for adjusting movement of the phosphor-containing liquid,
When the spray is sprayed by the spray nozzle, the movement adjusting unit pushes out the phosphor-containing liquid from the pressure tank and supplies it to the spray nozzle by supplying air to the inside of the pressure tank. In some cases, the phosphor coating apparatus is characterized in that the phosphor-containing liquid is pushed out from the pressure tank by the supply of air and is moved to the storage tank through the spray nozzle. The movement adjusting unit is
An air supply unit for supplying air into the pressure tank;
An air control valve for controlling the supply of air from the air supply unit to the pressure tank;
A liquid supply control valve for controlling the supply of the phosphor-containing liquid from the storage tank to the pressure tank;
A liquid movement control valve for controlling movement of the phosphor-containing liquid from the spray nozzle to the storage tank;
In the spray injection, the movement adjusting unit closes both the liquid supply control valve and the liquid movement control valve, and opens the air control valve to bring the air supply unit into the pressure tank. While supplying air, when the spray is not sprayed, the liquid supply control valve is closed, and the liquid movement control valve and the air control valve are opened, and the air supply unit supplies air to the inside of the pressure tank. The phosphor coating apparatus according to claim 1, wherein: The storage tank is located above the liquid level of the phosphor-containing liquid in the pressure tank,
The movement adjusting unit switches the air control valve from an open state to a closed state and switches the liquid supply control valve from a closed state to an open state at the time of non-spraying, thereby containing the phosphor in the storage tank. The phosphor coating apparatus according to claim 2, wherein a liquid is supplied to the pressure tank.   In the closed state, the air control valve is configured by a three-way valve that stops air supply from the air supply unit to the pressure tank and simultaneously releases the air in the pressure tank to the outside. The phosphor coating apparatus according to claim 3. A spray instructing unit for instructing spray injection by the spray nozzle and stopping thereof;
Further comprising: a valve control unit that controls opening and closing of the liquid supply control valve, the liquid movement control valve, and the air control valve based on an instruction from the spray instruction unit;
When the spray instruction is instructed by the spray instruction unit, the valve control unit closes the liquid supply control valve and the liquid movement control valve and opens the air control valve, while the spray instruction unit performs spraying. 5. The phosphor coating apparatus according to claim 3, wherein when the stop of injection is instructed, the liquid supply control valve is closed and the liquid movement control valve and the air control valve are opened. Further comprising a remaining amount detection sensor for detecting the remaining amount of the phosphor-containing liquid inside the pressure tank;
The valve control unit closes the air control valve and opens the liquid supply control valve when the remaining amount detection sensor detects that the remaining amount of the phosphor-containing liquid is a predetermined value or less. The phosphor coating apparatus according to claim 5. A stirring device for stirring the phosphor-containing liquid in the storage tank;
The said stirring apparatus has a stirring member which is located in the said storage tank so that it may become non-contact with the inner surface of the said storage tank, and stirs the said fluorescent substance containing liquid. The phosphor coating apparatus according to any one of the above.   The phosphor coating apparatus according to claim 7, wherein the storage tank is formed of a transparent container.   9. The phosphor coating apparatus according to claim 7, wherein the storage tank is made of ceramic.   The apparatus according to any one of claims 1 to 9, further comprising an extruding unit that pushes the phosphor-containing liquid in the storage tank into the pressure tank by applying pressure to the air in the storage tank. The phosphor coating apparatus described.   11. The phosphor coating apparatus according to claim 1, further comprising a flow rate adjusting valve for restricting a flow rate of the phosphor-containing liquid moving from the spray nozzle to the storage tank.   The air supply amount adjustment valve for further reducing an air supply amount to the pressure tank when the spray is not ejected than when the spray is ejected. Phosphor coating device.

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