JP4893537B2 - Light emitting module and manufacturing method thereof - Google Patents

Description

  The present invention relates to a light-emitting module including a light-emitting element having a light-emitting layer that emits light when supplied with power, and a method for manufacturing the same.

  Conventionally, there are provided various light-emitting modules that include a surface-emitting light-emitting element (for example, an organic EL element) having a thin light-emitting layer on a substrate and emit light in a planar shape when DC power is supplied. Has been.

  By the way, in this type of light emitting module, if the characteristics of the light emitting element are varied during manufacturing or the like, the light output varies among the light emitting modules even if the same DC power is supplied. For this reason, for example, when a large-area light source is configured, a plurality of the light emitting modules may be arranged in parallel to emit light. In such a case, a difference in light output occurs between adjacent light emitting modules. There is a problem that it looks bad.

Therefore, in order to suppress the variation in light output between the light emitting modules, each light emitting module is provided with a semiconductor memory storing the characteristics of the respective light emitting elements, and light emission is performed according to the characteristics of the light emitting elements read from the semiconductor memory. It is considered to control the power supplied to the element (for example, see Patent Document 1).
JP2007-173088 (page 4)

  However, when using a semiconductor memory in which the characteristics of the light emitting element are stored as in the light emitting module described above, in order to turn on the light emitting module, the characteristics can be read from the semiconductor memory, and according to the read characteristics. There is a problem that a dedicated lighting device capable of controlling the supplied power is required, and the configuration of the lighting device becomes complicated.

  The present invention has been made in view of the above-described reasons, and provides a light emitting module capable of suppressing variation in light output while enabling lighting with a lighting device having a relatively simple configuration, and a method for manufacturing the same. With the goal.

According to a first aspect of the present invention, there is provided a light emitting element having a light emitting layer that emits light upon being supplied with power, a pair of power supply terminals that are formed on the substrate and supply power to the light emitting element, and on the substrate. And an output detection terminal that generates an output having a predetermined relationship with the light output of the light emitting element when power is supplied to the power supply terminal, and feedback control of the power supplied to the power supply terminal based on the voltage of the output detection terminal The output detection terminal is connected to each power supply terminal via a resistance element, and each resistance element is fed to the power supply terminal so that the light output of the light emitting element is a predetermined reference. so that the voltage of the output detection terminals when the value is a specified value, the resistance value is characterized that you have been preconditioned.

  According to this configuration, since the output detection terminal generates an output having a predetermined relationship with respect to the light output of the light emitting element when power is supplied to the power supply terminal, in the lighting device, based on the output of the output detection terminal The light emitting element can be turned on with a desired light output only by performing feedback control for controlling the power supplied to the light emitting element. For example, when turning on a plurality of light emitting modules, if the power supplied to the light emitting modules is controlled so that the outputs of the output detection terminals are the same, variations in the light output between the light emitting modules can be suppressed. In other words, there is an advantage that variation in light output can be suppressed while lighting is possible with a relatively simple lighting device.

Further , according to this configuration, the output of the output detection terminal is set by the resistance value of the resistance element, so that the configuration of claim 1 can be realized with a simple setting.

The invention of claim 2 is a method for manufacturing a light emitting module according to claim 1, wherein a resistor forming step of forming a thin-film resistor which constitutes at least a part of the resistive element on the substrate, wherein While monitoring the light output of the light emitting element and the voltage of the output detection terminal, the power supplied to the power supply terminal is changed, and the voltage of the output detection terminal when the light output of the light emitting element becomes the reference value is the specified value. And a resistance value adjusting step of adjusting the resistance value of the resistor by trimming.

  According to the present invention, in the resistance value adjusting step, the resistance value of the thin film-like resistor formed on the substrate is adjusted by trimming, so that the optical output of the light emitting element is predetermined when power is supplied to the power supply terminal. The resistance value of the resistance element can be set easily and accurately so that an output having the above relationship is generated at the output detection terminal.

  In the present invention, since the output detection terminal generates an output having a predetermined relationship with respect to the light output of the light emitting element when power is supplied to the power supply terminal, in the lighting device, the light emitting element is based on the output of the output detection terminal. By simply performing feedback control to control the power supplied to the light emitting element, the light emitting element can be turned on with a desired light output. Therefore, the light output can vary with a relatively simple lighting device, but the light output can vary. There is an advantage that can be suppressed.

  The light emitting module of this embodiment includes a light emitting element that emits light when DC power is supplied, a pair of power supply terminals that supply DC power to the light emitting element, and an optical output of the light emitting element when power is supplied to the power supply terminal. And an output detection terminal for generating an output having a predetermined relationship.

  As shown in FIG. 2, the light-emitting element 1 includes a substrate 2 made of a light-transmitting insulating material such as glass, a thin-film anode electrode 3 provided on the substrate 2, and an anode electrode 3. It has a light emitting layer 4 provided, a thin-film cathode electrode 5 sandwiching the light emitting layer 4 between the anode electrode 3, and a sealing layer 6 made of, for example, silicon resin. Here, the light emitting layer 4 is an organic thin film that emits light when energized in the thickness direction, and the light emitting element 1 constitutes an organic EL element. The anode electrode 3 is formed of a light-transmitting conductive material such as ITO (Indium Tin Oxide), which is a transparent electrode material, and transmits light generated in the light emitting layer 4 to the substrate 2 side. On the other hand, the cathode electrode 5 is made of a metal (for example, aluminum) thin film, and reflects the light generated in the light emitting layer 4 to the anode electrode 3 side.

  With this configuration, if direct current power is supplied between the anode electrode 3 and the cathode electrode 5 so that the anode electrode 3 is an anode and the cathode electrode 5 is a cathode, light from the light emitting layer 4 is transmitted through the anode electrode 3 and the substrate 2. The portion corresponding to the light emitting layer 4 in the substrate 2 emits light in a planar shape. In the present embodiment, the anode electrode 3, the cathode electrode 5, and the light emitting layer 4 are formed smaller than the substrate 2, and the substrate 2 and the light emitting layer 4 are each formed in a rectangular shape whose sides are parallel to each other. The sealing layer 6 is formed to cover the surface and side surfaces of the cathode electrode 5 and the side surfaces of the light emitting layer 4. In the example of FIG. 2, the cathode electrode 5 is formed to be approximately the same size as the anode electrode 3, but the entire area does not overlap the anode electrode 3 in the thickness direction (part of the right end in FIG. 2). Part) is arranged so as to protrude from the anode electrode 3 so as to be shifted to the right in the figure with respect to the anode electrode 3. Here, the light emitting layer 4 extends along the end surface (the right end surface in FIG. 2) of the anode electrode 3 so as to exist in the entire region between the facing surfaces of the anode electrode 3 and the cathode electrode 5.

  As shown in FIG. 1, the power supply terminals include an anode power supply terminal 7 electrically connected to the anode electrode 3 and a cathode power supply terminal 8 electrically connected to the cathode electrode 5. The terminals 7 and 8 are provided on the substrate 2 of the light-emitting element 1 described above as shown in FIG. Specifically, each of the power supply terminals 7 and 8 is formed on one surface of the substrate 2 on which the light emitting layer 4 is provided, and at a portion around the anode electrode 3 and the cathode electrode 5. Each of the power supply terminals 7 and 8 is formed in a rectangular shape in contact with one side of the one surface of the substrate 2, and is disposed at each end portion in the longitudinal direction of the one side. On the one surface of the substrate 2, a first electric path 9 having a conductor pattern narrower than the power supply terminal 7 and continuous with the anode electrode 3, and narrower than the power supply terminal 8 and continuous with the cathode electrode 5. The first electric circuit 9 connects the anode power supply terminal 7 to the anode electrode 3, and the second electric circuit 10 connects the cathode power supply terminal 8 to the cathode electrode. Connect to 5.

  The output detection terminal 11 is formed in a rectangular shape in contact with the one side of the one surface of the substrate 2, like the power supply terminals 7 and 8 of each electrode, and is slightly more negative than the central part in the longitudinal direction of the one side. It is arrange | positioned in the position near the electric power feeding terminal 8. Each of the power supply terminals 7 and 8 and the output detection terminal 11 function as a terminal for connecting an external circuit (such as a lighting device described later).

  By the way, in the light emitting module M of the present embodiment, the output detection terminal 11 is connected to the power supply terminals 7 and 8 via the resistance elements R1 and R2, respectively. That is, a series circuit of a pair of resistance elements R1 and R2 is connected between a pair of electric circuits 9 and 10 connected to the power supply terminals 7 and 8, and the output detection terminal 11 is connected to the resistance elements R1 and R2. The connection point is connected via a third electric circuit 12 narrower than the output detection terminal 11. Here, it is desirable that the resistance value between both ends of the series circuit of the resistance elements R1 and R2 is a high resistance. Note that each of the electrical paths 9, 10, 12, the power supply terminals 7, 8, and the output detection terminal 11 are all formed by plating (for example, chromium plating) and are exposed to the outside without being covered with the sealing layer 6. Has been.

  Here, the resistance values of the resistance elements R1 and R2 are set so that an output having a predetermined relationship with the light output of the light emitting element 1 is generated at the output detection terminal 11 when power is supplied to the power supply terminals 7 and 8. Is done. Specifically, since the output detection terminal 11 obtains a voltage obtained by dividing the DC voltage applied to the power supply terminals 7 and 8 by the resistance elements R1 and R2 as an output, it is applied to the power supply terminals 7 and 8. The ratio of the output of the output detection terminal 11 to the magnitude of the DC voltage (the voltage generated between the output detection terminal 11 and the cathode power supply terminal 8) is the resistance element R1 between the anode power supply terminal 7 and the output detection terminal 11. And the resistance value of the resistance element R2 between the cathode power supply terminal 8 and the output detection terminal 11 is determined. Accordingly, when the light output of the light emitting element 1 is the predetermined reference value P0, the resistance values of the resistance elements R1 and R2 can be set so that the output of the output detection terminal 11 becomes a predetermined specified value V0. For example, when power is supplied to the power supply terminals 7 and 8, an output having a predetermined relationship with the light output of the light emitting element 1 is generated at the output detection terminal 11. In the present embodiment, the rated light output of the light emitting element 1 when the light emitting module M is turned on is set as the reference value P0.

  In short, the output of the output detection terminal 11 is determined based on the magnitude of the light output of the light emitting element 1 without depending on the supply voltage to the power supply terminals 7 and 8. As a result, the light output with respect to the supply voltage varies for each light emitting module M due to variations in the characteristics of the light emitting element 1, and the power supply terminals 7 when the light output of the light emitting element 1 becomes the reference value P0. Even if there is a variation in the supply voltage to 8, the output of the output detection terminal 11 when the light output of the light emitting element 1 becomes the reference P0 is uniformly the specified value V0. The specified value V0 is a voltage obtained by dividing the supply voltage V to the power supply terminals 7 and 8 by the resistance elements R1 and R2 when the light output of the light emitting element 1 becomes the reference value P0. The relationship of V0 <V is established.

  By the way, the resistance values of the resistance elements R1 and R2 are set when the light emitting module M is manufactured. That is, the method for manufacturing the light emitting module M of the present embodiment includes a resistor forming step for forming a thin film resistor constituting the resistance elements R1 and R2, and a resistance value adjusting step for adjusting the resistance value of the resistor. Contains.

  In the resistor forming step, as shown in FIG. 1, a fixed region R1a having a fixed resistance value and a trimming region R1b having an adjustable resistance value are provided between the anode power supply terminal 7 and the output detection terminal 11. One resistance element R1 is formed, and a second resistance element R2 including only a fixed region R2a having a fixed resistance value is formed between the cathode power supply terminal 8 and the output detection terminal 11. Here, the fixed region R1a and the trimming region R1b of the first resistance element R1 are connected in series between the power supply terminal 7 and the output detection terminal 11. The trimming region R1b is a region in which the resistance value can be adjusted by laser trimming, and thus the resistance value of the first resistance element R1 can be adjusted even after the resistor forming step.

  In the resistance adjustment process, as shown in FIG. 3, the light output from the light-emitting element 1 is monitored by the optical sensor 13 and the output from the output detection terminal 11 is monitored by the voltmeter 14. DC power is supplied to the power supply terminals 7 and 8 of the module M. The power supplied from the inspection power supply 15 to the power supply terminals 7 and 8 is controlled by the control device 16. The optical sensor 13 is disposed to face the light emitting surface (the lower surface in FIG. 3) of the light emitting module M, and the voltmeter 14 is connected between the output detection terminal 11 and the cathode power supply terminal 8. Here, the control device 16 receives the output of the light sensor 13 and gradually increases the power (voltage) supplied to the power supply terminals 7 and 8 until the light output of the light emitting element 1 reaches the reference value P0. Then, in a state where the light output of the light emitting element 1 reaches the reference value P0 and the magnitude of the power supplied to the power supply terminals 7 and 8 is fixed, the output of the voltmeter 14 (that is, the output of the output detection terminal 11) is The resistance value of the first resistance element R1 is adjusted so as to be the specified value V0. The resistance value of the first resistance element R1 is adjusted by performing laser trimming on the trimming region R1b of the first resistance element R1. It is also conceivable that a variable resistor is used instead of the trimming region R1b so that the resistance value of the first resistance element R1 can be manually adjusted.

  As described above, the light emitting module M manufactured by the above manufacturing method outputs to the output detection terminal 11 an output having a predetermined relationship with respect to the light output of the light emitting element 1 when supplying power to the power supply terminals 7 and 8. Arise. Therefore, when there is a variation in the characteristics of the light emitting element 1 for each light emitting module M, the supply voltage V to the power supply terminals 7 and 8 when the light output of the light emitting element 1 becomes the reference value P0 differs for each light emitting module M. However, the output of the output detection terminal 11 when the light output of the light emitting element 1 becomes the reference value P0 becomes the specified value V0 in all the light emitting modules M. In other words, when the output of the output detection terminal 11 becomes the specified value V0, the light output of the light emitting element 1 becomes the reference value P0.

  Next, the lighting device 17 that lights the light emitting module M of the present embodiment will be described.

  As shown in FIG. 4, the lighting device 17 includes a DC power supply E1, a series circuit of a switching element Q1, an inductor L1, and a capacitor C1 connected between output terminals of the DC power supply E1, and a switching element Q1 and an inductor L1. It comprises a so-called buck converter including a diode D1 connected between both ends of a series circuit of an inductor L1 and a capacitor C1 so as to connect the cathode to the connection point side, and a drive circuit 18 that controls on / off of the switching element Q1. That is, the output voltage of the lighting device 17 generated at both ends of the capacitor C1 is controlled according to the on / off of the switching element Q1 by the drive circuit 18. Here, a field effect transistor (FET) is used as the switching element Q1. The DC power supply E1 may be a full-wave rectified AC output of a commercial power supply using a diode bridge.

  Here, the light emitting module M is connected between both ends of the capacitor C1 so that the output voltage of the lighting device 17 (the voltage across the capacitor C1) is supplied to the light emitting element 1. That is, the anode power supply terminal 7 is connected to the anode side output terminal (one end of the capacitor C1) of the lighting device 17, and the cathode power supply terminal is connected to the cathode side output terminal (the other end of the capacitor C1) of the lighting device 17. 8 is connected.

  By the way, this lighting device 17 controls on / off of the switching element Q1 by the drive circuit 18 so as to perform feedback control for controlling the power supplied to the light emitting element 1 based on the output of the output detection terminal 11 of the light emitting module M. Thus, a control circuit 19 that controls the output voltage and a feedback circuit 20 that receives the output of the output detection terminal 11 and determines the operation of the control circuit 19 are provided.

  The feedback circuit 20 includes an operational amplifier OP1 and resistors R10, R11, R12, and R13. The difference between the output of the reference power source E2 that generates the specified value V0 and the output V1 of the output detection terminal 11 of the light emitting module M is provided. And a differential amplifier circuit that outputs the signal to the control circuit 19. Here, the output of the output detection terminal 11 is V1, the resistance value of the resistor R10 connected between the output detection terminal 11 and the inverting input terminal of the operational amplifier OP1 is r10, and between the inverting input terminal and the output terminal of the operational amplifier OP1. Assuming that the resistance value of the resistor R11 connected to is r11, the output Vf of the feedback circuit 20 is represented by r11 / r10 (V1-V0).

  The control circuit 19 generates a control signal for controlling on / off of the switching element Q1 in accordance with the magnitude of the output Vf of the feedback circuit 20, and outputs the control signal to the drive circuit 18 to thereby turn on the lighting device 17. Control the magnitude of the output voltage. Specifically, if the output Vf of the feedback circuit 20 is negative (that is, if the output V1 of the output detection terminal 11 is smaller than the specified value V0), the output voltage of the lighting device 17 is increased, and the feedback circuit 20 If the output Vf is positive (that is, if the output V1 of the output detection terminal 11 is larger than the specified value V0), the output V1 of the output detection terminal 11 is decreased by reducing the output voltage of the lighting device 17. To match.

  When the light emitting module M of the present embodiment is turned on using the lighting device 17 having the above-described configuration, the light emitting element 1 of the light emitting module M has a light output (that is, the output V1 of the output detection terminal 11 becomes the specified value V0) (that is, , The light is emitted at the reference value P0). Therefore, when a plurality of light emitting modules M1 are arranged and lit, even if there are variations in characteristics of the light emitting elements 1 between the light emitting modules M, the light emitting elements 1 are set to the reference value P0 for all of the plurality of light emitting modules M. The light output can be made to emit light, and as a result, the variation in the light output between the light emitting modules M can be suppressed. In short, the light emitting module M of the present embodiment can be lit by the lighting device 17 having a relatively simple configuration in which the power supplied to the light emitting element 1 is feedback controlled based on the output V1 of the output detection terminal 11 as described above. Nevertheless, there is an advantage that variation in light output can be suppressed.

  Further, the configuration of the lighting device 17 for lighting the light emitting module M of the present embodiment is not limited to the above-described one. For example, if the lighting device 17 having the configuration illustrated in FIG. Accordingly, by controlling the direct current supplied to the light emitting module M, dimming lighting that adjusts the light output of the light emitting module M becomes possible.

  A lighting device 17 shown in FIG. 5 replaces the feedback circuit 20 of the lighting device 17 shown in FIG. 4 and a current detection unit 21 that detects a direct current supplied to the light emitting module M and an output V1 of the output detection terminal 11. Represents the dimming level, and the storage unit 22 that stores the detected current of the current detection unit 21 as the reference current I0 when the value becomes the specified value V0 (that is, when the light output of the light emitting element 1 reaches the reference value P0). A dimming target value generation unit 23 that receives the dimming signal and the output of the current detection unit 21 and determines the operation of the control circuit 19 is provided. You may provide the operation part operated so that a light control level can be arbitrarily set between 0%-100%.

  The current detector 21 detects and detects the direct current supplied to the light emitting module M by monitoring the voltage across the resistor R20 inserted between the negative power supply terminal 8 of the light emitting module M and the capacitor C1. The current is notified to the storage unit 22 and the dimming target value generation unit 23. The storage unit 22 is connected to the output detection terminal 11 of the light emitting module M, monitors the output V1 of the output detection terminal 11, and detects the current detection unit 21 when the output V1 matches the specified value V0. The current is stored as a reference current I0. The dimming target value generation unit 23 uses the reference current I0 in the storage unit 22 when the set dimming level is a% (0 <a <100), and the current obtained by I0 × (a / 100) Is set to the target value I0 ′. Then, the dimming target value generation unit 23 outputs the difference between the target value I0 'and the current detection current I1 of the current detection unit 21 to the control circuit 19.

  The control circuit 19 generates a control signal for controlling on / off of the switching element Q1 according to the output of the dimming target value generation unit 23, and outputs the control signal to the drive circuit 18 to thereby adjust the output voltage of the lighting device 17. Control the size. Specifically, if the detection current I1 of the current detection unit 21 is smaller than the target value I0 ′, the output voltage of the lighting device 17 is increased, and if the detection current I1 of the current detection unit 21 is larger than the target value I0 ′, the lighting is performed. By reducing the output voltage of the device 17, the detected current I1 of the current detector 21 is made to coincide with the target value I0 ′.

  That is, if the light emitting module M of this embodiment is lighted using the lighting device 17 having the configuration shown in FIG. 5, the light output of the light emitting element 1 can be adjusted according to the set dimming level. Moreover, with respect to the light emitting module M, the reference current I0 when the light output of the light emitting element 1 becomes the reference value P0 is used as a reference, and the reference current I0 is multiplied by a value (a / 100) corresponding to the dimming level. Therefore, even if there is a variation in the characteristics of the light emitting element 1 between the light emitting modules M, all the light emitting modules M can be made to emit light with the same light output based on the reference value P0. In addition, variations in light output between the light emitting modules M can be suppressed. In short, not only the light output at the dimming level a = 100% is aligned with the reference value P0 in all the light emitting modules M, but also the light output at the arbitrary dimming level a is aligned in all the light emitting modules M. Can do.

  By the way, the light emitting module M comprises a lighting fixture with the lighting device 17 as mentioned above. In addition to a case (not shown) for housing the lighting device 17 and fixing the light emitting module M, the lighting fixture is provided with an optical member such as a lens as necessary.

  In addition, the light emitting layer 4 of the light emitting element 1 may emit light when AC power is supplied.

It is the schematic which shows the principal part of the light emitting module of embodiment of this invention. It is a schematic sectional drawing which shows a light emitting module same as the above. It is the schematic which shows the system configuration | structure at the time of manufacture of a light emitting module same as the above. It is a schematic circuit diagram which shows the structure of the lighting device used for the same as the above. It is a schematic circuit diagram which shows the structure of the other lighting device same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emitting element 2 Board | substrate 4 Light emitting layer 7,8 Feed terminal 11 Output detection terminal M Light emitting module R1, R2 Resistive element

Claims (2)

A light emitting element having a light emitting layer on the substrate that emits light when supplied with power, a pair of power supply terminals formed on the substrate for supplying power to the light emitting element, and a power supply to the power supply terminal formed on the substrate And an output detection terminal that generates an output that has a predetermined relationship with the light output of the light emitting element .
Illuminated by a lighting device that feedback controls the power supplied to the power supply terminal based on the voltage of the output detection terminal,
The output detection terminal is connected to each power supply terminal through a resistance element, and each resistance element detects output when power is supplied to the power supply terminal and the light output of the light emitting element reaches a predetermined reference value. light emitting module voltage terminals so that a specified value, the resistance value is characterized that you have been preconditioned. 2. The method of manufacturing a light emitting module according to claim 1, wherein a resistor forming step of forming a thin film resistor constituting at least a part of the resistor on the substrate, a light output of the light emitting device, and the light output The resistor is configured so that the power supplied to the power supply terminal is changed while monitoring the voltage of the output detection terminal, and the voltage of the output detection terminal when the light output of the light emitting element becomes the reference value becomes the specified value. And a resistance value adjusting step of adjusting the resistance value of the light emitting module by trimming .

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